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Oct. 11, 1938. a. M. BIRD " METHOD 2,132,316 J IGGING Filed July 23, 1934 5/ Sheei's-She'et 1 [Viki/V702: BYRON M, BIRD Oct. 11, 1938. B. M. BIRD ' 2,132,376 METHOD OF J IGGING Filed July 23, 1934 5 Shueets-Sheet 2 “.LNN A3 mNN434 ATT'x Oct. 11, 1938. ’B_ M_ BlRD 2,132,376 METHOD OF JIGGING Filed July 23, 1934 5 Sheets-Sheet 3 66 59 9 ' 43 92 1 ivl/f/vroe: BYRON M. Buan A777 Oct. 11, 1938. B.‘ M. BIRD 2,132,376 METHOD OF JIGGING Filed July 23, 1934 VB) 5 Sheets-Sheet 5 ‘ my]! 3 “a; -- "z ‘ )5” % )\.___ __ 9, § " a __ ~m a 1PerM/41395. 5’, " s; 5 8 6 _ F“ I I‘ f’ ' I: /'a D g T“ /7 I l ‘ X‘1” ' 0, ?zz/V702; BYRON M. 15x21) 53/ 64M 59/. A7722 Patented Oct. 11, 1938 , 2,132,376 UNITED STATES PATENT OFFICE 2,132,376 METHOD OF JIGGING Byron M. Bird, Columbus, Ohio, assignor to The Je?’rey Manufacturing Company, a corporation of Ohio Application July 23, 1934,: Serial No. 736,443 » In Great Britain July 24, 1933 17 Claims. (Cl. 209-500) This invention relates to the art of jigging, which in general is the stratification of a bed of material resting upon a screen by means of up ' 5 ward pulsations of water, or alternating upward and downward pulsations of water with respect to said bed of material. - The particular problem which this application will consider, as illustrative, is the strati?cation of raw coal into clean coal and refuse such as shale, “bone" and pyrite. This raw material is chosen purely as illustrative and not as restrictive, for the method disclosed may be employed for the stratification of other minerals. anism of Figs. 5 and 6 taken ‘on the line 7-7 of Fig. 5; . r ‘Fig. 8 is a sectional view taken on. the line,8--8 of Fig. 5; v . Figs. 9, 10 and 11 are typical time-velocity curves illustrating a single cycle of movement of the jigging ?uid with respect to a sieve, accord; ing to the method of my invention; and Fig. 12 is a graphical illustration of the condi- . tion of a bed undergoing jigging according to my 10 method at several stages of each cycle of 'opera~ tion. ’ > , - The principal function of jigging is to effect a One object of the invention is to provide a new ' separation of different classes of materials ac ' method of jigging by providing a new cycle of operation of the jigging ?uid, both as to the period of a complete cycle employed for pulsion, and suction, and as to the particular shape of a curve representing the pulsion and suction periods, as a ?uid time-velocity curve. ‘ ;cording‘ to speci?c gravity found in the native 15 state in one mass. In the art of coal cleaning, the problem is to separate the coal from the im purities found therewith, as it comes from a mine. Such impurities may be shale, “bone” and pyrite. Where a sized feed is employed with a Another object of the‘invention is to provide" jig, the problem is not unusually difficult of solu 20 a new and highly e?icient jigging stroke which is tion, but sizing requires considerable operation effective to stratify a large range of sizes of a raw on the coal and, of course, increases the cost of coal containing impurities according to the cleaning thereof. It is therefore desirable to speci?c gravities of its constituents. 2.5 effect a strati?cation and classi?cation of a. coal Another object of the invention is to provide a new cycle of operation of a jigging liquid which will give a high capacity of separation for the amount of liquid used and the amount of power consumed. 7 Another object of the invention is to provide a ' new method of controlling the admission and ex vhaustion of air under pressure to an air controlled jig and to introduce two new periods in acycle of 35 air control thereof. . ‘ Still another object of the invention is to pro vide a new method of controlling the periodic con dition of a bed of material undergoing a jigging operation to provide improved Strati?cation of 4,0 the materials thereof. v Other objects of the invention will appear here inafter, the ‘novel features and combinations being set forth in the appended claims. In the drawings: 45 , - ' Fig. .3 is a side elevational view of another form of ‘apparatus which may be employed to carry out - 1 - Fig. 4 is an end elevational view of the device of Fig. 3; ', ' , Fig. 5 is an enlarged detailed elevational view of a valve and eccentric mechanism which may be employed with the device of Figs. 1 and 2; Fig. 6 is a sectional elevational view of the device of Fig. 5; ‘ , Fig. 7 is a sectional view of the eccentric mech the stratification of an unsized feed or of a feed of a large size range and provides a more com plete separation of the clean coal and coal im purities than has heretofore been realized. The 35 method also reduces the amount of water and . power necessary to effect the cleaning of the raw coal and thus presents a more efficient method than thoseheretofore in use. While my inven tion realizes its greatest utility and advancement 40 in the art in the cleaning of an unsized feed, it also has certain distinct advantages when em ployed with a sized feed, as will hereinafter ap pear. Fig. 1 is an elevational end view of one form of apparatus which may be employed to‘ carry out my invention, parts being shown in section; Fig. 2 is a side elevational view of the device. of Fig. 1 with parts shown in section; . my method; bed without requiring a sizing operation, or, in 25 other words, to operate upon an unsized bedor a‘ bed comprised of a large range of sizes. It'is here that the principal problems of stratification are presented. My method is directed particu larly to a solution of these problems presented in so ~ The art of jigging of minerals thereby to stratify 45 . and separate the constituent particles of a raw ‘ mineral according to the speci?c gravities of the separate particles, particularly by the use of w fer as a jigging ?uid, is very old. _ Q te ‘generally, jigging’ devices comprise a 50 sieve ,or screen for supporting the raw material, some means for cyclically forcing water upward ly through‘ said sieve or screen and generally al~ lowing part of said water to return back through said screen. Part of said water ?ows over a dam or weir and carries with it the particles of the lower speci?c gravity, while the [particles of .v higher speci?c gravity collect on the screen or are ' drawn down into a hutch below the screen, they are small enough. Some means is provided 2,132,376 2 to remove the heavier particles of material ‘ac cumulated on the screen, generally constituting ‘a continuous process. " - 39 and each has communication with the upper part of a chamber 24, individual to each of the sub-compartments 31, 31, under the control of . ,As employed in this speci?cation and in the 5 claims, any movement of water upwardly through the sieve or screen will be a pulsion movement; thus, during each cycle of operation, there will be a pulsion period during which water moves up an eccentric-operated,‘ periodically-reciprocating valve 40. The structure details of a valve 40, which is particularly adapted to be used to carry out my method, are illustrated in Fig. 6 and will be considered more in detail hereinafter. wardly through the sieve or screen. Any move 10 ment of the ?uid downwardly through the screen will be a suction movement; thus, during any cycle of operation in which suction is used, there The plunger 4| of the valve 40 is connected by a connecting rod 42 to an eccentric mechanism 43 operated from the motor 44 through the gear reduction mechanism 45. The details of an ec centric mechanism which is particularly adapted will be a period during which water moves down wardly through the sieve or screen. A suction to cooperate with the valve 40 in carrying out my to prevent a suction stroke or period, and this may possibly be done in my method of operation. 20 However, as will hereinafter appear, I prefer to employ a suction stroke or period, for, in operat plate 46. which, with a stationary guide plate 41, method is shown in detail in Figs. 5, 6 and 7 and ' 15 stroke or period is not essential to a jigging oper . will be described hereinafter. ation and sometimes is not used. This is accom Adjacent the refuse outlet 229 is a refuse dis . plished by supplying su?icient water to the hutch charge chute having a pivoted pressure release ing upon an unsized feed, it has been found to be practically essential to proper strati?cation as it is particularly effective in separating the small 25 particles of refuse from the larger [particles of ' coal. V The term mobility, as-employed in this appli cation and in the claims is defined as that con 7 ditipn of the bed in which all of the particles are 30 just free to movewith' respect to each other. Before discussing in detail the method com prising my invention, it is deemed well to first consider certain apparatus which may be em— 35 ployed to carry out said method. ’ Two devices are illustrated in Figs. 1, 2, 3 and 4. either of which may be employed to carry out the method constituting my invention, in its broadest aspects. The device of Figs. 1 and 2 is also par directs refuse from the sieve 28 to a discharge control paddle wheel valve 48. Upon rotation of said paddle wheel valve 48, under the control of the mechanism hereinafter described, measured quantities of the refuse are discharged into the refuse chamber 49 where it may be removed by a 25 bucket-type chain elevator mechanism 50 which discharges the refuse at the port 5|. The driving chain of said elevator mechanism 59 is driven by motor 44 through the reduction gears 45 operat ing through a chain and sprocket mechanism 52. 30 In order to remove the ?ne particles of refuse which collect in the bottom of the hutch 26, a screw mechanism 53 is provided in the refuse sump 54 which delivers said ?ne particles to the refuse chamber 49 through a small door 55. Said door'55 is made just sufficiently large to al low the discharge of material from said sump 54 ‘to said refuse chamber 49 and is maintained small in order to confine the pulsion of the ticularly adapted to carry out the method of my ‘ jigging liquid to the said sub-compartments 31, 40 40 invention in one of its more speci?c aspects, and that of Figs. 3 and 4 in another speci?c aspect. Referring ?rst to the device illustrated in Figs. 1 and 2, there is seen a jigging compartment com prising a tank 20 mounted between upright sup 45 ports 2|, 2| carried on the base member 22 com prising a supporting frame. Projecting down wardly into the tank 20 and longitudinally dis :posed with respect thereto is a plate 23 which, with the bottom of said tank 20, forms a U-shaped 50 compartment providing an air chamber 24 and a washing chamber 25. Below said chambers 24 and 25 and comprising a part of the tank 20, is a hutch 26. Carried between the plate 23 and one - side wall 21 of said tank 20, is a sieve 28 which 55 may be in the form of a screen or perforate plate. Said sieve 28, is provided with reinforcing ribs 29 and, as viewed in Fig. 1, extends along a horizon tal line. As illustrated in Fig.2, said sieve 28 slopes downwardly toward the right and directs '60 refuse which is collected thereon toward the refuse discharge port 229. Adjacent the side wall 30 of the tank 20, there is provided a water inlet conduit 3| in communi cation with any desired source of water supply. 65 A hand-operated valve 32 is provided in said con duit 3| to regulate the ?ow of water to the hutch 26. At 33 there is seen a source of air pressure which may comprise a blower, the output of which is delivered to a pressure tank 34 by a con 70 duit 35. From said pressure tank 34 extend indi vidual conduits 36, one for each of the sub-com partments 31, 31, into which said tank 20 is divided as by a laterally-disposed, vertically-ex tending plate 38. The conduits 35 may each be 75 provided with a manually-operable control valve 31 and to prevent any substantial pulsion of the ?uid. in the refuse chamber 49. The mechanism for operating the refuse paddle wheel valve 48 is substantially the same as that illustrated in the ‘device of Figs. 3 and 4 and will be described in 45 connection with said ?gures. However, the driv ing pawl is reciprocated by a driving mechanism driven from motor 44. The material to be jigged is fed to the device at the inlet 56 and progresses to the right, as viewed in Fig. 2 across the sieve 28 during the jigging operation. Fine refuse particles are drawn through said sieve 28 into the hutch 26 and large refuse particles collect on said plate 28 to be discharged through the refuse port 229. The jigging liquid ?owing over the bailie or weir 51 carries with it the cleaned coal which is dis charged at the discharge chute 58. It is to be noted that the valves 40, for each of the sub-compartments 31, 31, are operated from a single motor 44; thus they are operated in synchronism. However, each of said valves 40 is individually adjustable and in addition the ec centric mechanism 43 for each of said valves 40 is individually adjustable. Therefore, the par 65 ticular cycle of operation of each of the sub compartments .31, 31 may be individually con trolled and varied at will. In addition, each of said sub-compartments 31 is provided ‘with its individual conduit 3| and water control valve .32 whereby the amount of water of jigging fluid which is admitted to each of said sub-compart ments 31 may be individually controlled. The individual valves 39, 39 provide additional in dividual and independent control of the admis 75 2,132,376 sion of air to the chamber 24 of each of the sub compartments 31. Referring to ‘Figs. 5, 6, 7 and 8, there,‘ is dis closed an eccentric-operated valve mechanism particularly adapted to carry out my method of operation in the device illustrated in Figs. 1 and 2. However, neither the valve structure, per se, nor the eccentric structure, per se, illustrated in Figs. 5, 6, 7 and 8, is my sole invention but each is 10 the invention of another party. As illustrated in said Figs. 5 and 6, the valve'40 comprises a cylin der 59 provided near the upper part thereof with circumferential inlet ports .60 communicating with a circumferential .chamber 6| provided with 15 a pipe ?tting 62. Adjacent the lower part of said cylinder 59 are a plurality of discharge ports 63 communicating with atmospheric pressure. The bottom'part of said cylinder 59 communicates with a belled conduit 64 forming the upperv part of the air chamber 24. The upper part of the cylinder 59 is provided with a head 65 having an integral guide sleeve 66. 3 adjustment is made between said pistons 61 and 68, said pistons are adapted to move in unisonv under the control of the connecting rod 42. By virtue of the adjustability afforded by the screw threaded connection between the threaded por tion 14 of the hollow sleeve 13 and the cooperat ing threaded portion of the guide thimble'l5, said guide thimble 15 may be adjusted with re spect to said hollow sleeve 13 and thus the posi tions of said pistons 81 and 68 may be adjusted 10 for any given position of the connecting rod 42._ The upper end' of the connecting rod 42 'is connected to an eccentric mechanism 43. Said eccentric mechanism is of the variable throw type and may be of any well-known construction. There is illustrated in Figs. 5, 6 and 7 a par ticular eccentric mechanism which is well adapt ed for use in carrying out the method of my in-_ ' vention, particularly in conjunction with the valve 40. Said eccentric mechanism comprises a split strap 86 rigidly connected with the con necting rod 42. -Mounted upon shaft 81 for rota tion therewith, is a bushing 88 provided with a circumferential ?ange'89and a cylindrical hub 98. Said hub 90 is adapted to ?t into an oval shaped. opening 9| in an eccentric plate 92, which plate is carried rigid with the bushing 88 be tween the ?ange 8.9 and a retaining washer 93 Within the cylinder 59 is a pair of pistons 61 and 68. The piston 61 is adapted to control the opening andclosing of the inlet ports ‘68 and the piston 68 is adapted to control the opening and closing of the discharge ports 63. The piston 61 is provided with‘ a ‘central hub 69 and axially extending spokes 10. The spokes 10 permit the _ bolted to said bushing 88.. The stroke of the 'free'movement of the air received through the connecting rod 42 .is, of course, controlled by inlet port 60, through the. cylinder 59 to the con the displacement of .the'axis of the eccentric duit 64 and into the air chamber 24, when said plate 92 and the axis‘ of the shaft 81;'that is‘, » piston 61 is in said inlet port opening position. The piston '68 is also provided with a hub 1| and spokes 12in order to allow the above mentioned the stroke will be twice this displacement. In ' order to control variably the stroke of said con necting rod 42, the eccentric plate 92 is made adjustable with respect to said bushing 88 where Rigidly attached to the hub 69 is a hollow sleeve by said axial displacement may be controlled 13 adapted to be guided in the guide sleeve 66. at will. The oval-shaped opening 9| permits The upper end of said hollow sleeve 13 is screw relative adjustment between said eccentric plate threaded as illustrated at 14 and is adapted to 92 and said bushing 88. To effect this adjust screw-threadedly receive a split guide thimble 15 vment, the ?ange 89 is provided with three angu which may be clamped rigid thereto after having larly-displaced conical holes 95' adapted selec been adjusted to a desired position with ‘respect tively to receive'the frusto-conical head 95 of a to the threaded neck portion ‘not said guide pin 94, the axis of which is displaced with re thimble 15. The inner cylindrical surface of said spect to the axis of said pin 94. Said pin 94v free passage of air through the cylinder 59.v guide thimble ‘I5 is adapted to slide on the outer surface of the guide sleeve 66. A U-shaped link ‘l8 carrying a connecting rod 42 is pivoted to later-. 50 ally-extending lugs 8|], 89 of the thimble 15. Projecting through the longitudinal opening 8| of the hollow sleeve 13 is a shaft 82 rigidly attachedat its lower end with the hub ‘H of the piston 68 and adjustably connected to the hollow sleeve ‘I3 at its upper end by screw threads 83. 55 A clamping nut 84 is provided for clamping said shaft 82 ‘rigid with said hollow sleeve 13 after the former is adjusted to a desired position. To provide for the adjustment of said shaft 82 with is adapted to be received in a drill hole in the plate 92. The axial extension 91 of said con ical head 95 is‘screw-threaded to receive a nut 96 and at its extremity is squared to receive a too]. By virtue of this adjusting device, the posi tion of the bushing 88 with respect to said eccen tric plate 92 may be adjustably determined and ?xed in adetermined position. This is accom plished by placing head 95 in one of the three singularly-displaced holes 95' and rotating said .55 pin about its axis to move the hub 90 of bush ing 88 to any desired position in the oval-shaped opening 9| where it may be‘ held by‘ clamping respect to said hollow sleeve 13, the top of said ,home the nut 96. As illustrated in Fig. 7, the distance between the outer wall of the hub 99 within the oval opening 9| and the wall de?ning said opening 9| may be adjusted by rotation of shaft 82 is preferably squared as indicated‘ at 85 whereby a wrench may be employed to rotate said shaft 82 and thereby effect its adjustment.v The portion 19 of sleeve 18 is also squared to receives, tool and thus prevent its turning with shaft 82 during its adjustment. " I As the piston 61 is rigidly attached to the hollow sleeve '13 and as the piston 68 is rigidly attached to the shaft 82, it is obvious that by rotating said shaft 82, which is screw-threaded 70 at 88 with said hollow sleeve 18, the position of the piston 88 may be adjusted with respect to the piston‘ 81. the pin 94 about its axis. This may be e?ected by a wrench ?tted on the axial extension 97. ' Along the section line illustrated in said Fig. 7, the mentioned walls are spaced at substantially their maximum distance. By rotating the head 95, the axis of the pin 94 will move downwardly, as viewed in Fig. 7, and will decrease the men--_ tioned distance. In addition to the above men 70 tioned adjustment, by removing retaining washer This adjustment may be made ' 93, it is possible to move eccentric plate 92 axi within wide limits and, when any‘desired ad ally and disengage the head 95 from one coni Justment is eifected. it may be maintained by 15 clamping home the clamp nut 84. After said cal hole 95' and rotate this plate either 120 or 240 ‘degrees, and place said head '95 in another 1| 13 2,182,878 conical hole. That is, plate 92 may have any one of three positions relative to bushing 88 vand connecting rod 42. By this expedient, the valves of any machine, though driven from a common shaft 81, may be in place or di?er by 120 or 240 degrees from any other valve. This provides for tained until the connecting rod 42 has substan tially completed its stroke in the upward direc tion under the control of the eccentric mecha nism 43. When connecting rod 42 substantially completes its upward stroke, said discharge ports 5 63 are opened while the inlet port GI is main non-synchronous admission of the air to the various sub-chambers which is sometimes desir able for various reasons. By employing the adjustable eccentric mech 10 anism and the adjustable dual piston valve mechanism illustrated in Figs. 5, 6, '7 and 8', very ?exible control of the. admission, mainte nance and discharge of air under pressure to the chamber 24 is provided. The adjustable eccen 15 trio mechanism provides for an adjustable stroke of the connecting rod 42 and a resulting adjust able stroke for the pistons 61 and 68 and for adjusting the phase relation between the two or 20 more valves. The adjustable thimble 15 pro vides for an adjustable determination of the limits within which said pistons 61 and 68 will operate for any given eccentric adjustment and any given relative adjustment of pistons-61 and 68; and the adjustment provided between the shaft 82 and the hollow sleeve 13 provides an adjustment for the relative positions of the pis tons 61 and 68 which, in turn, provides for the relative time of opening and closing of the inlet port 60 and the discharge ports 63. Instead of employing the eccentric mechanism 43 for oper tained closed and the chamber 24 is free to ex haust at, atmospheric pressure. During the fol lowing downward movement of pistons 61 and 68, exhaust ports 63 are closed while inlet port 80 is 10 maintained closed'and the chamber 24 is effec tively sealed. This completes a cycle of opera tion. In the specification and claims, the period dur ing which inlet port 60 is open and ?uid under 15 pressure is added to the air chamber 24, is desig nated the inlet period. The following period during which ports 60 and 63 are both closed is designated the expansion period. The following period during which exhaust ports 63 are open is 20 called the exhaust period and the ?nal period during which ports -60 and 63 are closed under initial atmospheric pressure is called the com pression period. It may be noted that with this particular valve construction, the expansion and 25. compression periods are of necessity of the same duration, while the inlet and exhaust periods may be varied within wide limits and be of di?er ent duration. ’ By lowering ‘1 the posi on of the piston 61 with 39 respect to the connecting rod 42, the period dur ating said valve 40, I may employ a cam device ing which the inlet port SI is maintained open and the cam surface may be given any desired _ may be increased and by raising said piston with respect thereto said period may be reduced. This period may be varied between wide limits, from 20 :15 ity of interchangeable cams may be provided to ‘ degrees to 300 degrees of movement vof shaft 01, afford greater ?exibility of operation of said by controlling the position of said piston 61 onv ‘said hollow sleeve 13. Likewise, by lowering the valve 40. ' position of piston 68 with respect to connecting With the valve‘ 40 and the eccentric 43 ad justed as illustrated in Figs. 5 and 6, and with the rod 42, the period during which the discharge 40 con?guration for operating valve 40 through any desired cycle of operation. If desired, a plural shaft 81 rotated in a counter-clockwise direction~ as viewed ‘in Fig. 5, the cycle of operation of the admission, maintenance, and discharge of the air to the chamber 24 will be substantially as v ' follows: With valve 40 in the position illustrated in m. 6, both the inlet port 60 and. discharge ports 63 ports 63 are open may be reduced and by rais ing said piston with respect thereto said period may be increased. This period. may also be varied between “the limits above mentioned for , piston 61. It is to be noted that thelength or 45 the piston 61 is such that under no condition may said piston be moved upwardly su?icient to open the inlet port 60. This requires the opening of initial atmospheric pressure following a period of ' the. inlet port 60 to take place only during the downward movement of the connecting rod 42. 50 exhaustion of chamber 24. As the shaft 81 ro The piston 68 is also 'of.such length and is pre!- _ tates counter-clockwise and the pistons 61 and erably so adjusted that under no condition will 68 are moved downward, the inlet port 60 is the discharge ports 63 be opened duringa down opened as the eccentric device “'43 approaches the ward movement of the connecting rod 42. That lower limit of its stroke. The discharge ports 63 is, inlet port 60 under the control of the piston 55 are maintained closed through this portion of the 61 is ‘adapted to be opened only in response to a cycle. It may be noted that as the inlet port 60 downward movement_ of the connecting rod 42 does not begin to open until the eccentric 43 has anddischarge ports 63 under the control of pis approached the downward extremity of its stroke ton 88 are adapted to be opened only in response that the rate of opening of said port 50 will be . to an upward movement of vthe connecting rodtco small in comparison with what it would have been 42. Furthermore, the pistons i1 and ‘i are pref had said port ‘started to open at approximately erably so adjusted that under no condition will the instant the axis of the eccentric plate 9| ports 60 and 63 be open at the same .time for, if passed below the axis of the shaft 81. With the. this condition exists, the air under pressure will connecting rod 42 in its extreme downward posi enter the cylinder 59 through the inlet port ‘I and 65 85 tion of the stroke, the inlet port 60 will be com be discharged to the atmosphere through the pletely opened and the discharge ports 63 will be discharge ports 53 thereby wasting the air and are closed and the chamber 24 is sealed at an closed. Under these conditions, the ?uid under doing no useful work. . * 'I pressure would be admitted to the chamber 24 It is obvious that the portion of any cycle of to produce upward movement of the jigging ?uid operation during which inlet port 5! is opened 70 throughv the sieve 28. On the return movement . and discharge ports 64 closed may be varied-with of the connecting rod 42 under the control of the in wide limits. Likewise, the portion of eccentric 43, the inlet port 60 is closed while the during which discharge ports 63 are opened and outlet ports 63 are maintained closed. Under inlet port 60 is closed may be varied within wide these conditions, the chamber 24 is effectively ' limits.- In addition, the condition under which sealed under pressure and this condition is main 70 - ' ' .15 2,132,878 5 both the inlet port 50 and the discharge ports 63 IOI at Ill and is pivotally connected to the are closed may be varied within wide limits and, piston rod I07 at the point “0 intermediate the in fact, this period may be reduced. to substan ends of said piston rods I07. The jigging ?uid tially 0 or increased to substantially 150 degrees. resting on the piston I05 exerts a downward It may be noted, however, that with this valve _ force thereon which force may be at least par construction this period cannot exceed, even tially balanced by the coil spring II 4 operating 5 theoretically, 180' degrees and as a practical through the lever H0 and its extension H2. The matter-the limit is probably about 150 degrees. lever H0 is provided at its lower face with an In addition, the rate at which the ports 00 and 03 arcuate rack H9 with which is adapted to co 10 are opened or closed once their respective pis tons commence an opening ~or closing operation operate a gear I20 carried upon the upper end of an arm Iii provided at its lower end with a may be varied by varying the stroke of the con ‘ necting rod-42 and by varying the instant during any cycle of operation at which said opening or roller wheel I22 adapted to ride upon the cam I23_carried on the shaft I24 which is supported '15 closing operation begins. The latter is, of course, determined ‘to a large extent by the portion of the cycle a valve is adjusted to be opened, while the ‘ former is independently adjustable. That is, if the portion of a cycle de?ning the limits during -20 which port 60, for example, ?rst starts ‘to open until it is totally closed, is small, such as 60 de to the frame IOI by bearings I26, I20. A link I2‘! is pivoted at I 20 at one end thereof to link 15 I21’ and at its other end is pivoted to the arm I2I at the' axis of said roller wheel I22. Said link I27’ also carries pivot III'and is centrally ?xed to bracket I28’ carried by frame "II. By rotation of the gear I20, the. position of the‘ upper 20 grees, then it‘ begins to open when eccentric 43 the lever I I0, thereby adjustably controlling the approaches the lower part of its stroke, during length of stroke of the piston rod I01 during which the rate ofmovement of- piston 61 is rela each cycle of operation. When said gear I20 is tively small. ' adjacent the left hand end of said rack “9, as It is thus obvious that with the eccentric viewed in Fig. 3, the stroke of said piston rod I0'I ' 25 operated valve structure, illustrated in Figs. 5, will be a minimum and when it is adjacent the 6, 7 and 8, the period during which ?uid is ad * right" hand end'of said rack, the stroke of said mitted to the chamber 24, the rate of this admis piston rod will be av maximum. slon, the period during which the discharge ports Theshape of the cam I23 may, of course, be 30 _ 63 are opened and the-rate of opening thereof, may each be varied within wide limits, thus pro viding a very flexible means for controlling the movement of the jigging ?uid with respect to the sieve 20 and the consequent condition of the bed of material undergoing jigging. Y In Figs. 3 and 4, there is illustrated another device which may be employed to carry out the end of arm I 2| may be adjusted with respect to made anything that is desired and may be made to control the operation of the piston I05 to per form the method of my invention. It the device of said Figs. 3 and A is to be operated for dif ferent cycles comprising my method, more than 35 _ one cam I23 will be provided each with a dif ferent shape whereby different speci?c embodi ments of my invention may be realized. It will, method of my invention, at, least in some of its .of course, be appreciated that the shape of the aspects. This device‘ is similar to the device in cam I23 will determine the particular shape of 40v Figs. 1 and 2 in a number of respects. The de the curve representing the flow of ?uid through scription will be directed principally to the dif ferences between-said device and that of Figs. 1 and 2. Instead of employing air under pres sure to perform the jigging operation, the de vice of Figs. 3 and 4 employ mechanical means for this purpose. Said device comprises a tank I00 mounted upon a frame designated generally by IN. The tank I00 is provided with a sieve I02 which is horizontal along a transverse axis of said tank and slopes downwardly to the right along a longitudinal axis thereof. Said sieve I02 may be of substantially the same construction as. the sieve 28 in the device of Figs. 1 and 2. Said sieve leads to a refuse port I03 which is in com munication with the refuse chamber I04 of sub stantially the same construction as the refuse chamber "illustrated in Figs. 1 and 2. The bottom of the tank I00 comprises a piston I05 ?exibly connected to the bottom wall of the tank I00 by a ?exible ring I06, which may be the sieve I02 and by predetermining the shape of a cam any desired curve may be obtained. In this respect this particular mechanism is more ?exible than that of Figs. 1 and 2 for there is 45 no restriction on the shape of the ,cam and nothing analogous to the requirement of equal expansion and compression periods oi.’ the air valve thereof. As above indicated, by making a plurality of cams of different shapes, a plurality of curves may be followed. Adjustment of the 50 gear I20 will, of course, merely control the am plitude of the stroke of a single cycle but will in no wise vary the general shape of the curve representing said cycle of operation. An electric motor I29 driving through a. belt 65 I30 and a V-belt variable speed mechanism I3I . made of rubber. Said ?exible ring I00 allows vvibratory movement of the piston I 06 which is effective to control periodically the ?ow of the and a gear-type speed-reduction mechanism I32 is provided for driving the shaft I24 at any de sired variable speed. 60 The discharge chute I04 is provided with a discharge paddle wheel valve similar to the. paddle wheel valve 40 of the device of Figs. 1 "jigging ?uid inside of the tank illgwwith respect to the sieve I02. To reciprocate the piston I05, ?oat mechanism I33 which is effective to render a mechanism is provided comprising a piston rod "I01 extending downwardly with said piston I05 and rigidly attached thereto as by reinforcing .70 webqs I00. ‘Said piston rod IN is pivoted at I 09 to a lever I I0 pivoted at III and provided with an extension H2 carrying a piston II3 adapted to move upwardly against the tension of the spring H4 carried in the guide cylinder “5. A U 75 shaped guiding link H0 is pivoted to the frame ' and 2 which is operated under the control as a operative or non-operative a pawl and ratchet mechanism I34, the pawl of which is constantly reciprocating under the control of the recipro-V eating rod I35 connected at one end to a crank I36 geared on the shaft I24 and at the otherend to one arm of the bell crank lever I37, the other arm of which carries a pawl I38. The position of the float I33 is adapted to be determined by the refuse carried by the sieve 28 or I02. Under the control of- refuse carriedon the said sieves‘ 28 2,182,376 6 the time of closing thereof. The “Exhaust valve open” indicates a similar condition with respect to the exhaust ports. The "Expansion-compres sion" column indicates the portion of each cycle during which both the inlet ports and the ex haust ports are completely closed. ‘These pe riods are inherently equal. The "Stroke of valve" and I02, the ?oat I33 is controlled and through the link I38 controls a semi-cylindrical shield I40 adapted to control the engagement or non engagement of the pawl I38 and a ratchet wheel I4I rigidly connected to the shaft of said refuse discharge valve 48. When said refuse becomes of predetermined depth, the ?oat I33 is lifted, column is the stroke of the air valve which de termines the rate of opening and the rate of thereby rotating the semi-cylindrical shield I40 in a counter-clockwise direction as viewed in Fig. 3. This removes the wall of said shield I40 closing of the inch stroke is for this cycle of the port at which previously prevented the engagement of the pawl I38 with the ratchet wheel “I. The refuse discharge valve 48 is then operated by the reciprocating pawl I38 to discharge the accumu inlet and exhaust ports. A 11/2 10 indicated by curve E on Fig. 9 ofv operation, in which the. size any interval of time after either the inlet or exhaust valve starts to open or close is given in square inches per square foot of 15 screen surface. Curves E on Figs. 10 and 11 give similar indications for a 1. inch stroke and 15 lated refuse on the sieve 28 or I02. When said refuse has been discharged or reduced to a de sired level. the ?oat I33 moves downwardly and through the link I38, rotates the shield I40 a 1% inch stroke respectively for the cycle of operation illustrated in said ?gures. whereby it is interposed between the pawl I38 and the ratchet wheel “I, thereby preventing the operation of said ratchet wheel even though the pawl I38 is continually oscillating. Fig. 12 is a graphic illustration of several con 20 ditions of a bed undergoing jigging according to my method and the various stages thereof are approximately indicated on the curves of Figs. A bucket-type chain elevator indicated gen erally by I42 is provided to lift the refuse from 9, 10 and 11 by the numbers corresponding to the bed condition or stage numbers. It will, 25 the elevator boot I43 and discharge it at the of course, be obvious that each stage merges into outlet I44. ' ' ' the next stage and no clear cut limits there In the operation of the device of Figs. 3 and 4, between are possible. Furthermore, a stage may the coal to be cleaned enters the tank IOI ad jacent the end I45 and is subjected to a jigging~ not occur at the exact location indicated on the 30 30 operation while forming a bed above the sieve curve but may appear at either side thereof. I02. The refuse is discharged at the port I03 However, an attempt is made to illustrate with and the clean coal ?ows over the bailie I46 to observation accuracy the limits of each stage. It "may be stated that the arrows adiacent each the discharge chute I41. The fine refuse ac cumulated in the hutch I48 may be discharged number represents the approximate extent of ' 35 into elevator boot I43 through an opening I48’. each stage. Stage 1 is the initial stage and represents the A valve I41’ is provided to control the supply condition of the bed with the mass of the par of water to the hutch I48 from conduit I48’. Referring particularly to Figs. 9, 10 and. 11 ticles resting on the sieve or screen, but with the top layers in partial suspension, which par 40 tial suspension is indicated by the particular of the drawings, there is illustrated three time 40 velocity curves which represent the velocity of the waiter ?owing through a sieve or screen dur- _ shading there illustrated. Stage 2 illustrates substantially the same bed condition as is illustrated by Stage 1 but with the entire bed raised to a slight extent above ing a complete cycle of operation. Each of these curves illustrates the method of my invention, in one of its aspects, and illustrates a cycle of 45 jigging operation which has been found to pro duce an improved and highly e?lcient result. the sieve or screen. Purely by way of illustration and not as a limitation, it may be stated that Figs. 9,. 10 and 11 represent a curve obtained with a jig of the general type illustrated in Figs. 1 and 2, with the exception that it had only one hutch compart ment 3‘! and one air valve 40, the screen area layers have fallen toward the sieve or screen somewhat, or in other words, are in an open 50 condition. Stage. 4 illustrates the condition in which the top of the bed is raised still more and the bottom layers have fallen downward, the opening of the mass of the particles having extended to 55 approximately the center of the bed. being 1/2 square foot area, the coal being %-0 bituminous or soft coal. The following table gives the other conditions of operation, for a 55 tonnage of 2000 pounds, per hour: , ' Air (tlg‘rves Cycles it ate/rt , prcs- 60 0 1g.—— per mm. . sec. . sure lbs./in.1 9 45 . 0376 2. 9 10 11 B0 45 . 0376 . 0376 , 2. 9 29 Ex Expan 333g hglusi; 3i‘); Stggke ‘2W1 ' open. gig; valve Degree: 180 Degrm 45 Inches 1}‘ 120 120 , 60 60 > ‘ Degree: 90 120 120 v ve ' Stage-8 illustrates the condition in which the top of the bed is raised still more but the bottom _ 1 1% Stage 5 illustrates, the condition where the top of the bed has approached its maximum height and the bed is almost entirely open. Stage 6 illustrates the condition of full mobil 70 ity of the bed, where it is entirely open. the pressure in the air supply tank which re Stage 7 illustrates the bed condition in which mains vsubstantially constant. The “Inlet valve ' open" column indicates the portion of eachrcycle ‘the bottom thereof has closed but the greater open. during which the inlet ports are opened to any part of-the top is stillthe condition in which the 15 76 extent, thus covering the time of opening and > Stage 8 illustrates / By way of explanation, the “Water" column in dicates the amount of water used asexpressed in cubic feet/per second/per square ‘foot of sieve 70 or screen area. The "Air pressure” column is 2,132,376 ‘lower half of the bed is closed while the top part is still open. Stage 9 illustrates the ?nal stage in a cycle of operation, in which the bed is entirely closed. The several‘ stages, as above illustrated, are representative of the average bed condition dur ing a cycle ofv operation in which the bed is constantly receiving raw coal and discharging ?nished products; that is, under- full operating 10 conditions. - In Figs. 9, 10 and 11, there is illustrated three time-velocity curves A which represent the rate of ?ow of the jigging ?uid with respect to a sieve 7. observations from actual operation. Referring to Figs. 9, l0. and 11 and without consideration of ' the bed conditions. comparison of the pulsion period of curve A with the half cycle of sine wave . C which has the same maximum amplitude and same base, or time period is facilitated by dividing the total time of this period into four equal time periods indicated as a, b, c and d. Similarly, comparison of the suction period of curve A with the half cycle of sine wave D which has the same absolute maximum amplitude and same base or time period is‘ facilitated by dividing the total time of this period into four equal time periods or screen carrying a bed of material subject to _ 15 a jigging operation. Each of these curves is rep resentative of my method and each has been found to produce an improved strati?cation of materials. Of the three curves, that represented indicated as e, f, g and h. ' With reference to Fig. 9 and considering ?rst the pulsion period, 15 during the first part of period a, curve A rises at a rate less rapid than the sine curve C, or, by Fig. 9 is preferred, thoughno great di?erence stated in a different manner, the magnitude of the velocity is less than that of the sine curve 24117 appears to be found between the results of“ the three. The curves A of these Figs. 9, l0 and 11 ' C. In period b, the velocity is less than that of 20 may be obtained by any desired apparatus, as, sine curve C while the slope is greater.- The maximum amplitude of curve A and the sine for example, the apparatus of Figs. 1 and 2 or curve C appear at substantially the same time. that of Figs. 3 and‘ 4. There is illustrated at B in In periods a and d, the velocity is less than that 2425» each of said Figs. 9, 10 and 11 a typical pressure of the sine curve C and the slope of curve A is 25 curve which represents the air pressure in the greater than that of sine curve C except for chamber 24 when a jig of the general type illus trated in Figs. 1 and 2 is employed. There is .the last half of period it in which the slopeis also illustrated at F in Fig. 9 a wave curve, or a. 3d curve which is the‘integral of curve A. 'This curve represents the developed surface of a cam which should be employed to obtain curve A when a device like that of Figs. 3 and 4 is employed. That is, the entire curve represents 360 degrees ,35 of a cam and at spaced radial points the cam radius above a given base is given by the curve height. The zero ordinate of said curve repre sents the shortest radius of the cam and the maximum point represents the longest radius It is obvious that by a similar integra 40 thereof. tion of curves A of Figs-10 and 11, similar de veloped cam surfaces may be obtained. In addition, purely for comparison, there is il lustrated two sine waves, of half a cycle each, 45 one, C, for the pulsion period and one, D, for the suction period for each curve A, to form a basis for discussion of said curves A. Each of these sine curves has the same maximum ampli ture, in absolute value, as the corresponding 60 pulsion or suction period and has the same base as its corresponding pulsion or suction period thus representing the same time interval as said - period. It may be stated, that in the speci?ca tion and claims any relative or comparative term 65 or expression employed in describing either a pulsion or a suction period has as areference the half cycle of sine curve associated therewith. For example, if it is stated that the pulsion period ‘has a small rate of increasing velocity 60 during part of a period, it is meant that this rate of increase of velocity is small as compared with the increase in velocity represented by said sine less than that of sine curve C. It is also to be noted that the top ‘portion of curve A, represent ed by about one-fourth of the height thereof at the top, has a smaller radius of' curvature than the sine curve C. or in other words, persists during a shorter time interval than does the sine curve C. Considering next the suction period, in which absolute values will be considered throughout, during period 2 curve A has a greater velocity and a greater slope than the sine curve D. Dur ing period 1‘, curve A reaches its maximum value and changes its slope from negative to positive, also crossing the sine curve D. During periods gr and h, curve A has a velocity less than the sine curve and has a particularly pronounced change in slope near-the end of ‘period :7 with a velocity and slope much smaller than the sine curve D during period it. It may be stated that curves A. as well as the other curves of Figs. 9. 10 and ll, are drawn to scale and the maximum value of the water velocity during the pulsion period is approximately 8.5 inches per second and the maximum absolute ovalue of the suction period 150 I is approximately 4.7 inches per second. Considering curve A of Fig. 10 and comparing. it with the half cycle sine curves C and D, it is seen that during the’ ?rst part of period a curve A rises at a rate less rapid than the sine curve C. 0.1‘ stated in a different manner, the magnitude of the velocity is less than that of the sine curve C. During period b, the velocity is less than that of sine curve C while the slope is greater. The maximum amplitude of curve A appears near 60 the center of period c and thus at a ‘time later than the maximum amplitude of sine curve C. During the latter part of period c and during stant or over'the same period of time. period at, the velocity is greater than that of the Referring to Figs. 9, 10 and 11, there is indi~ ' sine curve ‘C and the slopeis greater than that of 65 cated by the several stage numbers along line said sine curve C. It is also to be noted that G—-G the periods of each cycle during which the the top portion of curve A has a smaller radius several bed conditions illustrated in Fig. '12 are of. curvature than the sine wave C, or in other realized. It is to be distinctly understood that words, persists during a shorter time interval 70 these conditions are approximate as to time, and than does the sine curve C. ' . 70 certain of ‘them may. vary appreciably from the Considering the suction period, in which ab positions indicated. It is also to be. understood ' solute values are considered, during period c that they'are not sharply de?ned, but merge, one .and most of period 1‘, the slope is greater than into the other. However, the representation that of sine curve D and the velocities greater. 75 given is in accordance with the best obtainable The maximum value occurs near the center of ' Wave as a time-velocity curve at the same in 1 2,132,876 8 period I. During the latter part of period 3‘ and substantially the whole of period g, the velocity is much less than the sine curve D and has a greater slope. An abrupt change in slope isgseen at the end of period 9 followed by a velocity and slope both smaller than the sine curve D during‘ period It. The maximum value of .r the pulsion period velocity is approximately 5.9 inches per second, and the maximum absolute value of the 10 suction period is‘ approximately 6.1 inches per value of the velocity is smaller than the sine curve and the slope is greater. Also near the end of this period, the slope decreases rather abruptly. During period h the velocity is smaller than the sine wave and the slope quite generally smaller. It is also to be noted that the pulsion and suction periods need not be of equal time duration, though they may be, and in the illustrations given they are not. In the illustration of Fig. 9, the pulsion period 10 is much shorter than the suction period; in the illustration of Fig. 10, the pulsion period is some Considering next curve A of Fig. 11, and com paring it with the half cycle sine curves C and D, what long-er than the suction period; while in it is seen that during the ?rst part of period a the illustration of Fig. 11, they are nearly equal, 15 the suction period being slightly longer. 15 curve A rises at a rate less rapid than the sine Near the bottom of each of the Figs. 9, 10 and curve C, or the magnitude of the velocity is less than that of sine curve C. During period b, the - 11, there is indicated along line G-G, by the velocity follows the sine curve rather closely. numerals I through ‘9, the extent of each of the bed conditions illustrated by Fig. 12 as these bed The maximum amplitude of the curve A substan occur under the action of the water 20 tially coincides with that of the sine curve C. conditions During period c the slope is greater than that of passing through the sieve or screen according to sine curve C‘ and the velocity less. During period the time-velocity curve A of that ?gure. ' A dis (I the velocity is less than that of C and the slope cussion of the water action and the consequent bed condition and stratifying action which takes less. It is again to be noted that the top por place withcurve A of Fig. 9 will be representative 25 tion of curve A has a smaller radius of curva of the entire group, due account being taken in tu're than the sine wave C, or in other words, each case as to the position of the bed condition persists during a shorter time interval than does the sine curve C. Considering the suction indicating numerals. In this consideration, I set period, it is seen that it is essentially the same as forth, not only my belief as to the bed condition 30 it changes under the control of the jigging that of Fig. 10 and the description of said Fig. 10 as ?uid during each cycle of operation, but my may apply with equal force to Fig. 11. The maxi theory as to the reasons why this jigging cycle mum value of the pulsion velocity is approximate produces an improved. result. However, it is to ly 7.2 inches vper second, and the maximum ab be understood that I am not bound by this theory, solute value of the suction period is approxi for whatever the reason may be, and regardless 35 mately 5.6 inches per second. the mode of stratification, it is known that . As a general statement respecting each of the of the particular cycle of operation illustrated by curves A of Figs. 9, 10 and 11 many time-velocity time-velocity water curves illustrated, pro curve representative of my method of operation, _ the duces an improved and desirable jiggling cycle. it vmay be stated that in comparing .the pulsion In a given feed, stratification of the coarser 40 40 period with a half cycle of a sine curve having sizes according to speci?c gravity, is primarily a maximum amplitude and a frequency equal to by the pulsion periods; the stratification the maximum amplitude and frequency thereof effected of the ?ner sizes must be effected by the suction and comparing the suction period with a half periods. In other words, properly used, the suc cycle of a sine curve having a maximum ampli tion periods make it possible to treat a large tude and a frequency equal to the maximum am of sizes in one operation. However, the plitude, in absolute value, and frequency thereof range suction periods are only effective between the and dividing each half sine curve into four equal time the water starts downward and the time the time intervals, designated a, b, c, d and e, f, g‘, h, bed closes. During this short interval, the sepa respectively, the following conditions will main ration is according to speci?c gravity and with tain, though certain exceptions may be encoun out regard to the size and shape of the particles tered. During period a and particularly during being treated. If, during the pulsion periods the ?rst part thereof, the magnitude of the veloc which occur intermittently between the suction ity will be small as compared with the sine curve periods, the bed is held in a condition of mobility or the rate of increase of velocity will be small. for a longer time than necessary for the particles 55 This characteristic is almost always obtained. to become free to move; that is, if there is any During period b, the magnitude of the velocity sustained mobility in any part of the bed, the may be greater or less than the sine curve but jig in effect becomes an upward current classi?er quite generally the slope thereof will be greater, and stratifies ?ne refuse with coarse particles of at least over the ?rst half of the period. During 60 period c, the velocity may be greater or less than coal. To whatever extent this occurs, it nulli?es the effect of the separation according to speci?c the sine curve but if the velocity is greater the obtained in the suction periods. The result slope will be less and if the velocity is lower the gravity is a great loss in capacity in the jig, or the actual slope will be equal to or greater on the average. Period (1 may vary considerably depending on discharge of the ?ner, particles of refuse with the 65 washed coal. In my improved method, the pul 65 period c. In addition, it is quite uniform that sion period is effective to give a nearly simul the top of the curve, representing about one taneous opening of the whole bed presenting a fourth of the ordinates from the top down, has condition of full mobility followed by a quick ’ a smaller radius of curvature than the sine curve, closing of the bed and thus avoiding in a large or in other words, persists over a smaller time measure the deleterious effects of any sustained 70 70 interval than the sine curve. During period e, period of bed mobility; the velocity is greater, in absolute value, than As seen in said Fig. 9, during the ?rst part of the sine curve and the slope is greater. The peak period a the water velocity upwardly through the of the‘ suction stroke quite generally appears in screen increases slowly and is less than the sine period I, or at a time in advance of the peak of curve C. This is followed by an increasing rate 75 15 the sine curve. During period 9, the absolute second. , - . arsasvc 9 of ?ow during the latter part of said period. ated water jigof the type illustrated by Figs. 3 I The ?rst part with the slow increase in velocity, and 4. Where the latter is used a cam is formed partially opens the top of the bed‘ as indicated by the bed condition character I. However, be fore the bed can open, the increased rate of water velocity lifts the entire bed as a whole oil the‘ sieve or screen, indicated by the bed character 2, so that there is a freedom of the bottom particles to move. This freedom of movement allows the 10 coarse particles of refuse normally found near the screen to fall back and become mobile. This condition is indicated by bed character 3. As . the water continues to increase in velocity, it lifts the upper'layers further and the bottom 15 layers continue to drop off the bed. to produce the desired time-velocity curve A in the manner above described in connection with curve F of Fig. 9. Where an air controlled jig is used, designated generally in the art by the name Baum type, the curves A of Figs. 9, 10 and ii may be obtained by setting the valve shown in detail in Figs. 5 and 6 as indicated by the table hereinabove and on Figs. 9, 10 and 11. ‘This set 10 ting of water, air pressure, air volumeand stroke is for a tonnage of 4000 pounds per square foot per hour of bituminous or soft slack coal of %-0 size range. The same water volume would hold for a cam type jig. Certain variations may 15 be necessary with different coals and particu This con tinues further, as indicated by bed characters It andv 5, until the bed is entirely open as indicated - larly if a different size range‘or a di?'erent tons by bed character 6. It is to be noted that the nage is used. Knowledge of these. variations full mobile condition as indicated by bed char will be easily acquired by skilled operators and 20 acter 6 is indicated as appearing on the latter will, of course, be made in carrying out the meth 20 part of period c, or after the maximum velocity od as employed under conditions not identical is reached. 'It may be that this condition is realized much sooner, for example, near the end of period b or before the maximum velocity is reached. However, the entire bed opening, par ticularly from bed condition 3 to bed condition 6, with the illustrations given. With high .peak velocities required for ‘coarse coal it may be neces sary to operate the jig at lower speeds to give’ ample timefor the bed to open. This is particu 25 larly necessary on the cam produced stroke. or full mobility, takes place in a rather short Referring again to the curve A of Fig. 9 as time interval. # illustrative of all of the A curves and considering The deceleration of the ?uid, or decrease in ‘ particularly the four periods of operation of the 30 velocity after the peak velocity is reached, ‘is air valve, comprising inlet or air admission, -eX- 30 more rapid than the sine curve, as is seen during pansion, exhaust and compression, the resulting period c and the ?rst part of period d; This'is pressures in the air chamber as indicated by effective to reduce to a minimum the separation curve B and the resulting time velocity ?uid or as an upward current classi?er which tends to -water curve A; it is seen that ‘the velocity is zero stratify 'the fine refuse with the larger particles at substantially the "instant the valve starts to 35 of coal. It also allows opening of any top layers open, but the pressure in the air chamber is ap which were possibly not previously completely preciable. The water reaches its maximum ve opened. It is also to be noted that the rapid locity during the air admission or inlet period and decrease in velocity after the peak velocity is .starts to drop off while this valve is still open. reached has as an incident the maintaining of The maximum air chamber pressure is reached w the higher pulsion velocities for a relatively short time. . During period e, which is the ?rst part of the suction period, and particularly during the first 45 part thereof, the ?uidflows down through the screen under the'pull of gravity. The bed is in the condition indicated by bed character ‘I, with the bottom layers closed and most of the top open. During this part of the period, there is a maxi mum separation of particles accgrding to speci?c gravity. With the-bed completely mobile at the beginning of this period, this period reaches its maximum e?’ectiveness. This action continues into periods 1‘ and g as indicated by bed char 55 acter 8 until a distinct downward pull is caused in the topmost layers of the bed. After this period has reached its maximum effectiveness, toward the end of period 9, the downward ?ow before the-maximum.?uid velocity is reached. During the expansion period, when both inlet and exhaust valves are closed, the water velocity de creases rapidly at least until the latter part thereof. During this decrease in velocity, the 45 air chamber pressures drop and may, as, in Fig. 9, actually become slightly negative. This means the continued upward movement of water which takes place after the air chamber is sealed, actually produces a negative pressure in said 50 chamber. This is a characteristic of a high maximum ?uid velocity and a short pulsion period as found in Fig. 9. The air pressures do not become negative in Figs. 10 and 11 where the pulsion period is longer and the maximum ve 55 locity is lower. In Fig. 9, the pulsion period ends at approximately the end of the expansion period. The suction period reaches its maximum of current is sharply reduced to prevent too solid ‘ downward velocity during the exhaust period, 60 a packing of the bed and the bed closes during when the exhaust ports are open, during which 60 the latter part of period 9' and during period it. . time the chamber‘ pressure is zero, as it is open The increased downward velocities during period to atmospheric pressure. Near the end of this c and part of period I is necessary inorder to period, the downward ?uid velocity decreases have strong suction throughout the bed and to rather sharply due to closing ofthe bed and its reach the topmost layers. However, to prevent consequent restriction to fluid flow. The com 65 extreme packing of the bed which would result pression period, with both valves closed, then in an undesired lifting of the entire bed during occurs and forms an air cushion for the ?nal I the ?rst part of period a of the pulsionperiod, downward movement of the ?uid, preventing it is desirable to retard the velocity of the ?uid severe packing of the bed. During this compres 70 during the latter part of the suction period or sion period, the pressure in the air chamber 70 during period It. gradually ‘rises. As has been above stated, the time-velocity It may be noted that in the curve A of Fig. 10 ?uid curves A of Figs. 9, l0 and 11 may be ob the. latter part of the pulsion stroke is during I _ tained by either an air operated water jig of the type illustrated by Figs. 1 "and 2 or a cam oper an exhaust period with a consequent very rapid rate of. deceleration of ?uid ?ow. It is also who w 2,182,876 10 noted that in this case the inlet or air admission period starts before the suction period is entirely ended. In some cases, it has been found that the compression period is effective not only to complete the suction period but actually starts a pulsion period before the air admission period to a chamber containing a jigging liquid adapted to be moved relative to a bed of material, each cycle of which constitutes 360 degrees and com prises, admitting a ?uid under pressure to said chamber for a period of a cycle to force said jig is started. The rate of opening and closing of the inlet and exhaust ports are indicated by curve E of 10 Figs. 9, 10 and 11. These rates, particularly the rate of opening of the inlet ports during air ad ging liquid upward through said bed, discon tinuing the admission of ?uid to said chamber, maintaining said chamber sealed for a period which may be variably determined at a value be— tween 30 and 150 degrees of said cycle and there 10 after opening said chamber to reduce said pres ‘ ~ mission, are effective to control the shape of the sure for a period. 4. The method of jigging by cyclically con curve A. It is obvious that by controlling the rate of opening and closing of the inlet and ex trolling the application of ?uid under ‘pressure haust ports, and by varying the relative periods to a chamber forming one leg of a U-shaped tank 15 of air inlet or admission, expansion, exhaust and carrying a perforate bed supporting plate in the compression, time-velocity ?uid curves A, of a other leg thereof, said tank containing a jigging‘ large variety of shapes may be obtained. This, in itself, is an important feature of my invention. The curves are also effected by the rate of water inlet, for by supplying su?icient water the suc tiorr stroke may be greatly reduced or even eliminated. The maximum upward ?uid ve locity may also be regulated by controlling the cycle of the air control valve and also by control ling the air pressure in the air reservoir. The speed of the jig or the frequency may be varied within wide limits. The range actually used has “ liquid adapted to be moved relative to said plate, each cycle of which constitutes 360 degrees and comprises, admitting a ?uid under pressure to said chamber for a period of a cycle to force said jigging liquid upward through said plate, dis continuing the admission of ?uid to said cham ber, maintaining said’ chamber sealed for a period which may be variably adjusted at a value from 25 20 to 150 degrees of said cycle and thereafter opening said chamber to reduce said pressure for a period. , ' 5. The method of jigging by cyclically con 30 Instead of employing the apparatus of Figs. 3 trolling the application of ?uid under pressure to a chamber containing a jigging liquid adapted and 4 to produce the desired time-velocity curve A, the apparatus disclosed in the application of - to be moved relative to a bed of material, each Byron M. Bird and Ernst F. Muller for Apparatus cycle of which constitutes 360 degrees and com for treating mineral materials, Serial No. ‘736,442, prises, admitting a ?uid under pressure to said 35 chamber for a period of a cycle to force said ?led July 22, 1934, may be employed. ' Obviously those skilled in the art may make jigging liquid upward through said bed, discon various changes in the details and arrangement _ tinuing the admission of ?uid to said chamber, ,of parts without departing from the spirit and maintaining said chamber sealed for a period of scope of the invention as de?ned by the claims not less than 30 degrees of said cycle and there hereto .appended, and I wish therefore not to be after opening said chamber to reduce said pres 40 been between 20 and 150 cycles per minute. restricted to the precise constructionlherein dis- closed. - Having thus described and shown “an embodi ment of. my invention, what I'desire to secure 45 by Letters Patentof the United States is: 1. The method of jigging by cyclically control ling the application of ?uid under pressureto a chamber forming one leg of a U-shaped tank carrying a perforate bed supporting plate in the other leg thereof, said tank containing a jigging liquid adapted to be moved relative to said plate, each cycle of which constitutes 360 degrees and comprises admitting a ?uid under pressure to said chamber for a period of said cycle less than 55 130 degrees to force said jigging liquid upward through said plate, discontinuing the admission of ?uid to said chamber, maintaining said cham ber sealed for a relatively long period of said cycle and thereafter opening said chamber to reduce the pressure therein for a period. sure for a period. ~ 6. The method of jigging by cyclically control ling the application of ?uid under pressure to a chamber, containing a jigging liquid adapted to be moved relative to a bed of materials, each 45 cycle of _which constitutes ,360 degrees and com prises, admitting a ?uid under pressure to said chamber for a period of a cycle to force said jigging liquid upward through said bed, discon tinuing the admission of ?uid to said chamber, 50 maintaining said chamber sealed for a period of not less' than 60 degrees of said cycle and there after opening said chamber to reduce said pres sure for a period. '7. The method of jigging by cyclically con 55 trolling the appllcation of ?uid under pressure to a chamber containing a jigging liquid adapted to .be moved relative to a bed of material, each cycle of which constitutes 360 degrees and com prises, admitting a ?uid under pressure to said chamberfor a period of a cycle to force said 2. The method of jigging by cyclically control liquid upward through said bed, discon i' ling the application of ?uid under pressure to. jigging a chamber containing a jigging liquid adapted to tinuing .the admission of ?uid to said chamber, maintaining said chamber sealed for a period of be moved relative to a bed of materiaL- each 65 cycle of which constitutes 360 degrees and com ' not less than 90 degrees of said cycle and there prises admitting a ?uid under pressure to said after opening said chamber-to reduce said pres ‘ chamber for a period of said cycle less' than 150 sure for a period. degrees to force said jigging liquid upward through said bed, discontinuing the admission of 70 fluid to said chamber, maintaining said chamber sealed for a relatively long period of said cycle and thereafter opening said chamber to reduce 8. The method of jigging by cyclically control ling the application of ?uid under pressure to a chamber‘ forming one leg of a U-shaped tank 70 carrying a perforate bed supporting plate in the other leg thereof, said tank containing a jigging 'liquid adapted to be moved relative to said plate, the pressure‘therein for a period. ‘ . each cycle of which constitutes 360 degrees and 3. The method of jigging by cyclically con trolling the application of, ?uid under pressure comprises, admitting a ‘?uid under pressure to I 2,139,876 said chamber for a period of a cycle to force said jigging liquid upward through said plate, dis‘ continuing the admission of ?uid to said cham ber, maintaining said chamber sealed for a period of not less than 120 degrees of said cycle and thereafter opening said chamber to reduce said pressure for a period. ' EhThe method of jigging by cyclically con ~ trolling the applicationof fluid under pressure 10 to a chamber containing a jigging liquid to be moved relative to a bed of material, each cycle of which comprises, admitting ?uid under pres sure to said chamber, sealing said chamber against air ingress or egress, opening said cham 15 ber to reduce the pressure therein and again sealing said chamber against air ingress or egress, the periods during which said chamber is sealed being variably determined at a valuebe tween 30 and 150 degrees of a cycle of 360 degrees. 10. The methodof jigging by cyclically con trolling the application of ?uid under pressure to a chamber containing a jigging liquid to be moved relative to a bed of material, each cycle of which comprises, admitting fluid under pressure 25 to said chamber, sealing said chamber against air ingress or egress, opening said chamber to re duce the pressure therein and again sealing said chamber against air ingress or egress, the periods during which said chamber is sealed being not less than 30 degrees of a cycle of 360 degrees. ' 11. The method of jigging by cyclically con trolling the application of ?uid under pressure to a chamber containing a jigging liquid to be moved relative to a bed of material. each cycle of which comprises, admitting ?uid under pres sure to said chamber, sealing said chamber against air ingress or egress, opening said cham ber to reduce the pressure therein and again ‘sealing said chamber against air ingress or egress, the periods during which said chamber is sealed being not less than 60 degrees of a cycle of 360 11 of a cycle of 360 degrees, thereafter opening said chamber to reduce the pressure therein, thereby‘ ‘stratifying the clean coal and refuse in different strata, and directing said refuse and coal into different channels. ' 15. The method of cleaning coal which com prises subjecting a bed of raw coal to a jigging operation by controlling the application of ?uid under pressure to a chamber containing a jigging liquid to be moved relative to said bed'of coal, 10 comprising cyclically admitting fluid under pres sure to said chamber for a period, sealing said chamber for a predetermined period which is at least half as long as said admission period, there after opening said chamber to reduce the pres 16 sure therein,» thereby stratifying the clean coal and refuse in different strata, and separating said strata. 16. The method of separating materials of dif ferent densities by cyclically varying the move-v ment of a ?uid with respect to a perforate sup port carrying a bed of said materials of different densities to stratify said bed, each cycle of which may be represented by a time-velocity curve hav ing successive pulsion and suction periods in which the curve of the pulsion period fairly close ly follows a half-sine wave of equal maximum value and time except for the following varia tions; (1) the slope thereof is lower at ?rst and then increases rapidly to a higher value as the curve peak is approached, (2) the crown of the curve has a smaller curvature, (3) the slope of the curve immediately after the crown is greater; and in which the curve of the suction period roughly follows a negative half-sine wave of equal maximum absolute value and time except that during the final part thereof it is consider ably less than said half-sine wave; thereby stratifying said bed of materials into strata of different speci?c gravities with the high gravity degrees. materials on the bottom and the low gravity ma 12. The method of jigging by cyclically con terms on top, and directing the stratified high trolling the application of ?uid under pressure and low gravity materials along different paths. 17. The method of jigging by cyclically varying to a chamber containing a jigging liquid to be moved relative to a bed of material, each cycle the movement of a ?uid with respect to a perfo rate support carrying a bed of materials of dif of which comprises, admitting ?uid under pres sure to said chamber, sealing said chamber. ferent densities to stratify said bed, each cycle of which may be represented by a time-velocity against air ingress or egress, opening said cham curve having successive pulsion and suction ber to reduce the pressure therein and again seal ing said chamber against air ingress or egress, periods in which the curve of the pulsion period ' the periods during which said chamber is sealed fairly closely follows a half-sine wave of equal being not less than 90 degrees of a cycle of 360 maximum value and time except for the follow degrees. ing variations; (1) the slope thereof is lower at 55 13. The method of jigging by cyclically‘con- - first and then increases rapidly to a higher value trolling the application of ?uid under pressure to as the curve peak is approached, (2) the crown a chamber containing a jigging liquid to be of the curve has a smaller curvature, (3) the moved relative to a bed of material, each cycle slope of the curve immediately after the crown is greater; and in which the curve of the suction of which comprises, admitting ?uid under pres sure to said chamber, sealing said chamber period roughly follows a negative half-sine wave of equal maximum absolute value and time ex— against air ingress or egress, opening said cham her to reduce the pressure therein and ‘again cept that during the final part thereof it is con sealing said chamber against air ingress or egress, siderably less than said half-sine wave, and in the periods during which said chamber is sealed which the bed of materialsbeccmes completely being not less than 120 degrees of a cycle of 360 mobile at a time which is reached after the peak degrees. . ~ velocity of the pulsion period is passed; thereby liquid to be moved relative to said bed of coal, stratifying said bed of materials according to specific gravities with the high gravity materials in the bottom stratum and the low gravity mate rials in the top stratuni, and directing said stratified materials along separate paths to e?'ect 7' comprising cyclically admitting ?uid under pres a separation thereof. 14. The method of cleaning coal which com prises subjecting a bed of raw coal to a jigging operation by controlling the application of fluid under pressure to a chamber containing a jigging sure to said chamber for a period, sealing said chamber for a period of not less than 120 degrees - BYRON M. BIRD.