Патент USA US2118139код для вставки
May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 235' 6 r____ 42.9 10 Sheets-Sheet 1 May 24, 1938. 2,118,139 s. w. BATH ET AL MACHINE FOR GRINDING FLUTES Filed June 1, 1936 l0 Sheets-Sheet 2 235' ‘ii 145 1,, jyezéru dzéwgey 77.? 79% May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 m /ru_ Fu _ _ l0 Sheets-Sheet 3 May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 10 Sheets-Sheef. 4 6 \ \ \ Q312 '55:“... May 24, 1938. s_ w, BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 10 Sheets-Sheet 5 ‘ +205 i 5%? rwmw _I‘ 12 ' I "Tiff-l __ |_._____._:___ _1.-_-_-_]______ ____L‘_j"1££ 63, J- i 1 J40 *" 158.141 1 ‘ —~+--- ----- Jé-Jd“If, Lax IW 1.. " 1m May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 '10 Sheets-Sheet 6 5 Z7220. withdrew May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 l0 Sheets-Sheet 7 \\ \ \ May 24, 1938. s. w. BATH ET AL ' 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 10 Sheets-Sheet 8 an! May 24, 1938. s. w. BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936' 10 Sheets-Sheet 9 May 24, 1938. s. w.- BATH ET AL 2,118,139 MACHINE FOR GRINDING FLUTES Filed June 1, 1936 10 Sheets-Sheet l0 EJ976675‘. fhA'aZAc d12191/8? kley WW. 2,118,139 Patented May 24, 1938' UNITED STATES PATENT orncr: 2.118,139 MACHINE FOR GRINDING FLU'I'ES Stanley W. Bath, Shrewsbury, and Ervin L. Ack ley, Worcester, Mass” assig'nors to John‘ Bath & Company, Worcester, Mann, a corporation of Massachusetts Application June 1, 1936, Serial No. 82,808 16 Claim. (CI. 51-92) This invention relates to the manufacture of taps for threading holes in metal, and relates more particularly to the ?nishing of the longi tudinal ?utes in such'taps or in other similar 5 articles. It is customaryvto rough out these ?utes with a milling cutter before the taps are hardened and to ?nish the ?utes by grinding after the harden ing operation. 10 Fig. 17 is a side elevation of the control mecha nism, looking in the direction of the arrow I‘! in Fig. 16; Fig. 18 is a left-hand side elevation of the table vide an improved machine for performing the the arrow iii in Fig. 1; Figs. 19 and 20 are front elevations of parts of said mechanism, looking in the direction of the arrows l9 and 20 respectively in Fig. 18; Fig. 21 is a detail plan view, looking in the di- 15 In the preferred form, our improved machine 15 of our invention relate to novel devices by which the operator may conveniently vary and control the operation of the machine through manipula tion and adjustment of the hydraulic mechanism. Our invention further relates to arrangements 20 and combinations of parts which will be herein after described and more particularly pointed out in the appended claims. ' A preferred form of the invention is shown in the drawings, in which 25 Fig. l is a front elevation of our improved ?ute grinding machine; Fig. 2 is a partial right-hand elevation, looking in the direction of the arrow 2 in Fig. 1; Fig. 3 is an enlarged front elevation of certain 30 control mechanism; Fig. 4 is a sectional plan view, taken along the line 4-4 in Fig. 3; Fig. 5 is a front elevation of a cam and cam‘ plate to be described; 35 Fig. 6 is a sectional plan view, taken along the line 6-6 in Fig. 1; Fig. 7 is a partial front elevation, looking in the direction of the arrow 1 in Fig. 6; Fig. 8 isv a detail side elevation, looking in the 40 direction of the arrow 8 in Fig. 6; Fig. 9 is a plan view of certain parts,'par'tly in , section, and looking in the direction of the arrow 9 in Fig. 3; - Fig. 10 is a sectional front elevation, taken along the line Iii-40in Fig. 9; Fig. 11 is a right-hand side elevation of certain parts, looking in the direction of the arrow II in Fig. 9; Fig. 12 is a left-hand detail side elevation, look ing in the direction of the arrow l2 in Fig. 9; Fig. 13 is a detail sectional view showing a speed control valve and taken along the line l3-l3 in Fig. 11; 55 Fig. 1; elevating mechanism, looking in the direction of 10 is hydraulically actuated, and important features 50 Fig. 16 is a sectional front elevation of certain ‘valve control mechanism shown at the right in It is the general object of our invention to pro ?ute-grinding operation. 45 showing the valve in successive di?erent posi tions; Figs. 14 and 15 are views similar to Fig. 13 but rection of the arrow 2| in Fig. 19; . _ Fig. 22 is an end view, looking in the direction of the arrow 22 in Fig. 21; Fig. 23 is a sectional plan view of the work spindle head, looking in the direction of the arrow 20 23 in Fig. 1; Fig. 24 is a. sectional side elevation, taken along the line 24-24 in Fig. 23; ' Fig. 25 is a detail side elevation, looking in the 1 direction of the arrow 25 in Fig. 23; ' 25 Fig. 26 is a'side elevation, partly in section, of certain index valve mechanism, looking in the direction of the arrow 26 in Figs. 1 and 27; Fig. 27 is a sectional front elevation, partly broken away and taken along the line 2l—2‘| in 30 Fig. 26; " Fig. 28 is a view similar to Fig. '27 but showing certain parts in a different position; , Fig. 29 is a front elevation of the index valve disc; 35 Fig: 30 is a side elevation thereof, looking in the direction of the arrow 30 in Fig. 29; _ ' a, Fig. 31 is a diagrammatic view showing the‘ hydraulic connections; and ‘Figs. 32 to ‘35 inclusive show successive steps 40 in a flute-grinding operation. Referring to Figs. 1 and 2, our improved ?ute grinding machine comprises a frame 40 having a wheel head 4! mounted in ?xed position thereon and supporting a grinding wheel W on a wheel 45 spindle 42. The wheel spindle may be rotated by any suitable driving mechanism, such as an electric motor or belt and pulley connection (not shown). - Vertical adjustment of work 50 A bracket 44 (Fig. 2) is siidable in guideways 46 on the front of the frame 40 and is movable vertically by a screw 46 rotatable in ?xed bear ings and threaded through a nut 41 ?xed on the 55 2 8,118,189 bracket 44. A bevel gear 49 is keyed to the screw 46'and is freely siidable thereon. The gear 48 is supported on the bracket 44 and engages a bevel A coil spring 85 is mounted on a reduced por gear 49 (Fig. 20) on a shaft 59 extending laterally to the side of the machine, where it is supported in a bearing 9| (Fig. 19) on the bracket 44. A gear 52 is keyed to the shaft 59 and meshes tion 89 of the plunger" and pushes the plunger provided with a crank arm 59 and handle '89. A hand lever 48 is pivoted at 99 on the plunger bearing and extends upward therefrom. The 10 tated. By ~ As the screw is held in fixed vertical posi _ ingly raised or lowered.‘ The handle 84 is used for major adjustments of the work-supporting bracket 44, but for finer adjustments, particularly during the grinding op 30 40 45 plunger portion 88 engages the rear end of the plunger bearing. tion, the nut 41 and bracket 44 will be correspond 25 to the right in Fig. 23 until the head center 8| engages the work or until a collar 81 on the with a smaller gear 83 mounted on a stud 54 and 10 turning the handle 98, the screw 48 may be ro 20 gitudinally of the table as indicated at 84 in Fig. 24. lower end of the lever 88 is forked as indicated at 99 (Fig. 24) and engages the inner face of the collar 81 previously described. By pressing the handle 88 to the right in Fig. 23, the head center 8| may be withdrawn to permit insertion or re 15 moval of the work. A dog or driver 92 (Figs. 23 eration, we provide an additional crank arm 1 . and 25) is mounted on an enlarged portion of the (Figs. 18 and 19) which is loosely mounted on t e head center 8| and is notched as indicated at 93 to loosely receive the shank of a tap T. outer end of the shaft 89. The hub 88 of the crank arm 51 is_provided Indexing mechanism with an offset axially extending bearing 99 for For the purpose of indexing the work, the head a plunger 69 having a toothed plate 8| (Fig. 22) secured to its outer end "and slidable between center 8| or the work spindle 82 is provided with guiding projections 92 (Fig. 21) formed on the a pinion 88 (Fig. 23)/ meshing with a gear 99 mounted on a counter/shaft 91 rotatable in a fixed offset bearing 59. bearing in the work head 83. At its opposite end A coil spring 93 (Fig. 19) is mounted in a pock et in the crank arm and normally forces the the countershaft 91 is provided with a ratchet plunger 89 to the right in Fig. 19, causing the wheel 88, the teeth of .which are engaged by a teeth on the plate 9| to engage the teeth of the pawl 99 pivotaily mounted on an index lever I99, which in turn is loosely pivoted on the outer end gear 92 which is fast on the shaft". ' The crank arm 91 is thus normally connected of the countershaft 91. The feed lever I99 is provided with a stud I9I direct to the gear 92 and shaft 99. Provision is made, however, for disengaging the toothed plate (Fig. 24) extending through an elongated slot I92 8| from the gear 92 when it is desired to make a in the upper end of an actuating lever I93 pivoted substantial adjustment in the position of the at I94 on the work spindle head 83. A piston rod I95 and piston I96 are siidable in bracket 44 by means of the crank handle 89. an index cylinder I91, and the piston rod is con For this purpose a bell crank 94 (Fig. ‘19) is piv oted at 65 on a projection of the bearing 59, and nected by a slotted head I98 and cross-pin I99 to is connected by a link 98 to a handle lever 91, the index lever I93, with the cross-pin extending which is pivoted at 68 to the upper end of the through a second slot “9 in the index lever. 40 Pipes III and H2 connect the opposite ends crank arm 91. By moving the handle portion 99 of the lever 91 downward, the bell crank 94 may of the cylinder I91 to an index valve mechanism be caused to withdraw the plunger 99 against “4 (Fig. 1) ‘mounted on the front side-of the the pressure of the spring 93, thus disengaging bracket 44 and connected by a pipe I I5 (Fig. 31) the toothed plate 6| from the gear 92. As soon to a high pressure supply pipe II6 which in turn as the handle portion 99 is released, however, the is connected to a pressure pump P. A shut-off valve H1 is preferably provided in plate and gear will be reengaged. The use of the handle 69 during the grinding operation will be the pipe II! for a purpose to be described. The valve mechanism “4 is also provided with an ex hereinafter explained. I A bed 19 (Figs. 2 and 19) is siidable forward haust pipe II8 through which liquid may be dis and rearward along guideways on the top surface charged to a reservoir 8. The index valve mechanism I I4 is shown in de of the bracket 44. An adjusting screw 1| is ro tatable in a bearing 12 at the front of the bed 19 tail in Figs. 26 to 30 and comprises a casing~in and is provided with a hand-wheel 13. The screw which is rotatably mounted a disc I29 having an 55 1| is threaded in a nut 14 on the bracket 44. For ward and rearward manual adjustment of the bed 19 is thus made easily available. A work table 19 is slidable transversely of the machine along guideways 19a and 15'’ (Fig. 2) on 60 the bed 19. The work table" (Fig. 31) is con nected by a piston rod 18 to a piston 18it siidable in a main hydraulic cylinder 11 shown in end view in Fig. 2. Pipes 18 and 19 (Fig. 31) connect the cylinder 11 to hydraulic supply and control mech 65 anism to be described. _ ‘ arcuate recess I2I in one face thereof and having smaller recesses I22 and I23 in the same face but provided with ports I24 and I25‘ extending through the disc from opposite ends of the re cesses I22 and I23. . The disc I29 is mounted on a short shaft I29 rotatable in a bearing I21 formed on the casing of the valve mechanism. The shaft I29 is pro vided at its outer end with an arm I28 (Fig. 1) extending upward into the path of index dogs I29 and I39 adjustably secured in a T-slot I3| in the front of the sliding table 15. I The exhaust pipe II9 (Fig. 27) is connected to a port I32 which communicates with the arcuate The tap T to be ground is mounted on the ' recess |2| in all working positions of the disc I29. 70 sliding work table 15 between a fixed tail center The pipes I II and H2 are also provided with ports 70 89 (Fig. 32) and a head center 8|. The head cen I33 and I34 respectively and the supply pipe H5 ter 9| (Fig. 23) is mounted in the end of a work is connected to a recess I35 (Fig. 26) behind the spindle 82 siidable and rotatable in a bearing in disc I29 and in constant communication with the the work spindle head 93 which is mounted on ports I24 and I25. When the index valve disc I29 is in the position 75 76 the sliding table 15 and which is adjustable lon Work spindle head 2,118,189 shown in Fig. 27, the supply pipe II 5 'is connected through the vport I25, recess I23 and the port I34 to the index cylinder pipe II2, thus giving the in dexing mechanism an operating or feeding move ment. At the same time, the pipe I II from the op posite end of the cylinder is connected through the port I33, arcuate recess I2I and port I32 to the exhaust pipe II8. At this time the port I24 10 and recess I22 are out of alignment with the port I33. 3 any desired position and directly controls the rate of travel of the sliding table. The reversing valve cylinder I40 (Figs. 9 and 31) is provided with end ports I60 and I6I com municating with cross passages I62 and I63. The cross passage I62 is connected by a branch pipe I64 (Fig. 31) to a pressure supply pipe I65 which in turn communicates with the pressure pipe I49 previously described. As substantially higher pressure is required for 10 operation of the index mechanism, it is custom ary to provide a reducing valve I66 between the When the valve disc I20 is shifted to the posi tion shown in Fig. 28, the supply pipe is con pipes H6 and I49 and a low pressure relief valve nected through the port I24, recess I22 and port ~ I61 in a branch pipe I68 connecting the pipe I49 15 I33 to the pipe III, which thus supplies oil under to the reservoir S. With this arrangement, sub 15 pressure at the right-hand end of the index cylin stantially lower pressure is provided in the pres der I0'I (as viewed in Fig.24) and gives the feed sure supply pipes I49, I65, and I64. ing mechanism an idle return stroke; At the The cross passage I62 (Fig. 31) is also con same time, the pipe H2 is connected through the nected by a pipe I10 to a casing I‘II containing 20 port I34 and arcuate recess I2I to the port I32 a poppet valve I12 under the control of a dog and exhaust pipe II 8, while the supply port I25 I13 on the sliding table 15 (Figs. 6 and '7) through and recess I23 are out of operative position. connections to be described. The casing I ‘II is The arm I28 is engaged by the dog I30 and also provided with a port "4 (Fig. 31) connected shifted from the right-hand position shown in to an exhaust pipe I15 communicating with the 25 Fig. 1 to the left-hand position indicated by the reservoir S. broken line as the table 15 is moved to the left to withdraw the work from the wheel. At the right hand limit of table travel, when the wheel is in the ?ute, the arm I28 is engaged by the dog I29 30 and is returned to the position indicated in Fig. 1, thus giving the indexing mechanism an idle re-* turn stroke without indexing action. On each engagement of the arm I28 by the dog I30, the piston I06 will move to the right in Fig. 24, and the pawl 99 will engage the teeth of the, ratchet wheel 98 and give the countershaft 91 a partial revolution which is communicated‘ through the gear 96 and pinion 95 to' the work The cross passage I63 at the opposite end or the reversing valve cylinder is connected through a pipe I'I6 (Fig. 31) to a second poppet valve casing I'I'I having a valve I18 under the control of a second dog I'I9 on the sliding table ‘I5. A port I80 in the casing I" is connected by a'branch pipe I8I to the exhaust pipe previously described. When the machine is in operation, both ends of the piston I4I are exposed to equal pressures. ex .cept as one or the other poppet valves is opened to partially relieve the pressure. Poppet valve control mechanism spindle 82, thus indexing and advancing the work The cross passage I63 in the left-hand end angularly. _ of the cylinder I40 is also connected through a 40 If it is desired at any time to discontinue the passage I 83 (Fig. 31) and pipe I 84 to a chamber indexing, the valve I" (Fig. 31) may be closed, I85 in a poppet valve control mechanism P. A after which the arm I28 and valve disc I20 may be shifted as previously described but no index 45 ing action will take place. Reversing valve and speed control valve The supply of liquid to the main cylinder ‘I1 is controlled by a reversing valve R (Fig. 31) 50 comprising a cylinder I40 having a ?oating piston or bobbin I4I freely slidable therein. The pipes ‘I8 and ‘I9 previously described con nect ports I42 and I43 in the cylinder I 40 to the opposite ends ‘of the main cylinder 'I‘I which actu 55 ates the sliding table. Exhaust ports I44 and I45 in the cylinder I40 are connected through an ex haust pipe I46 to the reservoir S. .An additional port M1 is connected through a speed-control device D (Figs. 11 and 31) to a 60 branch supply pipe I49 which provides oil under pressure. The speed-control device D is shown in detail in Figs. 11 and 13 to 15, and comprises a throttle valve plate I5I mounted on a short shaft I52 rotatable in ?xed bearings I53 and I54 65 (Fig. 11) and having an arm I55 secured to the front end of the shaft and provided with a handle I56 (Fig.2). _ By manually adjusting the handle I 66, the 70 throttle valve plate I5I will vary the ?ow of oil from. the supply pipe I49 through the port I51 (Fig. 11) to the passage I58 which connects the speed control device D to the port I41 in the re versing valve mechanism R (Fig. 31) . The throt 75 tle valve plate I5I may be manually adjusted to second chamber I86 in the mechanism P is con nected ‘to the pressure supply pipe I65 and a third chamber I8'I is connected by a pipe I88 to the exhaust pipe "5. The control mechanism P is mounted on an arm I89 (Fig. 4) secured to the bed ‘I0 and com prises a poppet valve I90 controlling communi cation between the chambers I86 and I85 and a 60 second poppet valve I9I controlling communica tion between the chambers I85 and I81. The parts are shown in Fig. 31 in the position assumed when the machine is at rest, with the poppet valve I90 closed to cut off pressure oil from 55 the pipe I84 and cross passage I63, but with pres sure oil supplied through the pipe I64, cross pas sage I62 and port I60 to move the ?oating piston or bobbin I4I to the left-hand position indicated in Fig. 31. At the same time the left-hand end of 60 the cylinder I40 is connected through the pas~ sage I 83 and pipe I 84 to the exhaust pipe I98 through the open poppet valve I9I. The detailed construction bf the mechanism P is shown in Figs. 3, 4, 16, and 17. Springs I92 and I93 (Fig. 16) are positioned under the valves I 99 and I 9I and tend to close said valves. The. stems of the valves I90 and I9I extend upward through suitable glands and are engaged at their upper ends by contact screws 70 I94 and I95 in opposite ends of a rock arm I96, pivoted on a bracket I91 mounted on the. arm I89 as previously stated. The rock arm I96 is con nected to an arm I98, which in turn is connected through a link I99 (Fig. 3) to a rock arm 200 4 8,118,188 having a pin 20I extending into a "slot 282 in a cam plate 203. The rock arm 200 is pivoted on the bed 10 and the cam plate 203 is mounted on a slide plate 205 (Fig. 4) vertically movable on a dove-tailed guideway 208 secured to the face of the bed 10. Upward movement of the slide plate 206 by mechanism to be described causes the cam plate 203 to move the rock arm 200 and shift the link 10 I99 in the direction of the arrow a in Fig. 3. This in turn moves the arm I88 and rock arm I86 in a direction to depress and open the poppet valve I90 (Figs. .16 and 31) and to permit simultaneous closing of the poppet valve I9I by its spring I93. 16 The valves I90 and I9I are then in a position which is the reverse of that shown in Fig. 31, and the pressure supply pipe I65 (Fig. 31) is then con nected through the chambers I86 and I85 to the pipe I84 and through the passage I83,v cross pas sage I63 and port I6I to the left-hand end of the cylinder I40 of the reversing valve mechanism R. As the right-hand end .of the cylinder I40 is always supplied with pressure 011. through the pipe I 64, both ends of the cylinder are then under equal pressure and the bobbin I“ will remain in whatever position it happens to occupy until one or the other of the poppet valves I12 or I18 are opened to reduce the pressure in the associated end of the cylinder I40. , If the piston MI is in the position shown in Fig. 31 and the poppet valve I12 is open, the pres sure pipe I64 will be connected through the pipe I10, casing HI and port I 14 to the exhaust pipe 115, thus reducing the pressure in‘ the cross pas sage I62 and in the right-hand end of the cyl inder I40. As full pressure is still maintained in the left hand end of the cylinder, the piston .I4I will‘be shifted to the right, connecting the port I41 to the port I43 and thus admitting oil under pressure through the pipe 19 to the left-hand end of the main cylinder 11,. plate 206 is moved upward. Such upward move ment acts through the rock arm 200 and link I 88 to shift the poppet valve control mechanism P as previously described and place the machine in condition for operation. The upward movement of the slide plate 286 also lifts the lugs 2I6 and 2I6 into the path of travel of the dogs I13 and I18. It is of course un derstood that these dogs, as well as the dogs I29 and I30 previously described, are all conveniently 10 adjustable lengthwise of the sliding table 15 and that they may be secured in adjusted position by bolts 226 for the dogs I28 and I30 and by handle nuts 226 for the dogs I13 and I19. The dog I13 (Figs. 6 and 7) is pivoted at 221 16 to an adjustable support 228 and has a projection 229 engaging an abutment 230 on said support. The dog I13 thus swings freely in a clockwise direction but is rigidly held from movement in the opposite direction. This permits a run-o? of the table 16 to the left beyond the position deter mined by the dog I13, when desired. ‘ The operative faces of the dogs I13 and I19 are also beveled or inclined to correspond to the bevel of the lugs 2I6 and 2I8. The sliding table 16 is preferably provided -25_ with‘ an upwardly extending wall 236 (Figs. 23 and 24) enclosing the head and tail stocks and protecting the mechanism from grinding wheel dust. A shelf 236 (Fig. 2) may be mounted on 30 the front side of the table ‘wall 235 for the con-' venience of the operator. A supply pipe 231 (Fig. 31) extends from the reservoir S to the pump P. Operation have been described at considerable length in con nection with the detail description of the parts, but for convenience a comprehensive statement of the cooperation of the several parts will now 40 be given. The operation to be performed is indicated in Figs. 32 to 35, in which a tap T is shown mounted The piston “I will remain at the right-hand end of the cylinder I40 until the poppet valve I18 ' between tail and head centers 80 and 8| and is opened, whereupon the pressure in the left positioned for engagement by a grinding wheel W. hand end of the cylinder I40 will be reduced and In Fig. 32 the parts are shown just after a fresh the piston I H will return to the position shown tap has been inserted,the tap being loosely po in Fig. 31, with oil under pressure supplied sitioned angularly by the dog 92. The tap is through the ports I41 and I42 and pipe 18 to the then raised to the level of the wheel, as indicated right-hand end of the main cylinder 11. in Fig. 33, and the sliding table isimoved to the The connections between the dogs I13 and I19 right, carrying the work under the wheel. and the poppet valves I12 and I18 will now be The table is then reciprocated, as indicated by described. the double arrow in Fig. 34, and the work is raised very slightly during the grinding operation un Manual and automatic control of table travel til the desired polished surface is attained. A reversing lever 2I0 (Figs. 6 and 7) is loosely The work is then lowered and removed to the mounted on a shaft 2I I, which in turn is sup left, as indicated in Fig. 35, in which position the ported in a bearing in the slide plate 205. A tap is indexed, after which the described opera downward projection of the lever 2I0 terminates tions are repeated, this procedure being followed in a ball-shaped end 2I2 positioned between the until all'?utes of the tap are ground.‘ heads of the poppet valves I12 and I18. The lever Major adjustments of the work vertically are 2I0 also extends upwardly to provide a handle accomplished by use of the handle 56 (Figs. 18 2I3 and a rearward projection 2“ (Fig. 6) of and 19) after the toothed plate 6| has been with the lever 2 I 0 supports oppositely disposed lugs 2 I5 drawn from engagement with the gear 52 by and 2I6, having downwardly inclined outer faces rocking the handle 69. The raising and lower positioned for engagement by the dogs I13 and ing of the work during the grinding’operation, I19 respectively. as described in connection with Figs. 32 to 35, A handle 220 is connected to the front end of is accomplished by swinging the arm 51 (Figs. the shaft 2“ and a lifting cam 22I (Figs. 3, 5,_ 18 and 19). 70 and 8) is secured to the rear end of the shaft 2I I. The reciprocating motion of the table is under The cam 22I cooperates with a cam opening in the control of the manually operated handle 220 ’ plate 206 fixed to the front of the bed 10. (Fig. 4) and cam 22I (Figs. 3 and 5) by which By swinging the handle 220 upward toward the plate 205 and reversing lever 2I0 are raised vertical position, the cam 22I is moved in a clock 75 wise direction as indicated in Fig. 5 and the slide 35 Many features of the operation of the machine 45 I 50 56 60 70 or lowered. When the plate 205 is raised, the cam slot 202 75 5 2,118,189‘ reverses the position of the rock arm I88 forming part of the poppet valve control mechanism P, which action opens the valve I00 and closes the valve ISI' (Fig. 31). This supplies oil under pres sure through the pipe I84 to the left-hand end of the reversing valve cylinder “0, all as pre viously described. quire further attention unless a change in class of work takes place. > . Having thus described our invention and the advantages thereof, we do not wish. to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is: l. In a grinding machine. a sliding table, table-moving mechanism, a single control device . Oil under pressure is thus supplied at both ends of the ?oating piston or bobbin “I and the for said mechanism, table-reversing means, and , manual means to move said device toward and 10 10 piston Ml moves toward one end or the other of the cylinder as one or the other of the poppet valves 112' and H8 is opened to relieve the pres away from the path of table movement,_said de vice when moved by said manual means toward sure on the associated end of the cylinder H0. said path placing said machine'in operation and The lifting of the slide plate 205 not only said device when additionally moved by said man 15 brings the lugs 215 and 216 on the vreverse lever ual means in the same direction being effective to 15 2l0 into the path of movement of the dogs "3 change the range and extent of working travel and H9, but by reason of the inclined surfaces of said table as de?ned by said reversing means on the lugs and associated dogs, the length‘of . and during a grinding operation. stroke of the sliding table 15 and the travel of the 2. In a grinding machine, a sliding table, dogs work supported thereon is also controlled by the on said table, table-moving mechanism, a control 20 extent of lifting action. _ and reverse lever for said mechanism which is By swinging the handle 220 through a greater normally in lowered inoperative position, and or less arc, the cam 22| will lift therslide plate 265 a greater or less distance and the dogs I10 and I19 will engage wider or narrower portions manual means to move said lever vertically into position for engagement by said dogs and by further movement to vary and determine the 25 length of the working stroke of said table during a grinding operation. 3. In a grinding machine, a sliding table, dogs of the lugs M5 and 2H5 on the reverse lever M0. The higher the reverse lever and lugs are po sitioned, the longer will be the travel of the table in both directions. This manual control of table travel is of particular advantage in a machine for grinding ?utes, as the ?utes in different taps vary slightly in length and it is desired to grind each ?ute far enough to provide a bright surface but not far enough to force the wheel into solid metal. By operating the lever 220 with one hand ‘and the lever 51 with the other hand, the operator can easily control both the depth and length of the cut, so that an effective grinding operation on said table, table-moving mechanism, a con trol and reverse device for said mechanism, a 30 support on which said control and reversing de vice is movably mounted, ‘said support being ‘ normally in lowered inoperative‘ position, and manual means to raise said support and to there by move said device into the path of travel of said dogs. 4. In a grinding machine, a sliding table, dogs on said table, hydraulic table-moving mecha is quickly performed. nism, a control and reverse device for said mecha nism, a support for said device, means to lower said support so that said device will clear the dogs, and table-stopping means controlled by said . When the slide plate 205 is lowered at the end of the grinding operation, the poppet valve con; trol mechanism P is returned to initial position and shifts the valves I90 and I9! to the position shown in Fig. 31 with the pipe I 84 connected to the exhaust. lowering movement. 5. In a grinding machine, a sliding table, a pair of associated reversing dogs on said table, 45 table-moving mechanism, a control and reverse device for said mechanism normally out of posi The ?oating piston “I will be immediately shifted to the left in Fig. 31, connecting the pipe 18 to the pressure supply and moving the table 15 to the left until further travel is prevented by tion to engage either of said dogs, means to move said device into position for alternate engage ment by both of said dogs, and automatic means 50 to immediately move said table to reloading po sition, and stop said table in such position when a stop collar 240 on the piston rod ‘I6. Near the end of this left-hand travel, the dog I30 engages the arm I28 of the index mechanism, shifting the position of the valve disc I20 (Figs. ever said device is moved out of operative rela 27 to 30) and’ effecting the indexing of the work. tion to both of said dogs and regardless of the As the table 15 completes its left-hand travel, an abutment 22811L (Fig. 7) engages the rearward projection 2“ on the reverse lever 2 l0 and swings the lever anti-clockwise to open the poppet valve I12 (Fig. 31). This relieves the pressure on the right-hand end of the piston I“, so that the direction of travel of the ‘table when said device 65 piston will move immediately to the right as soon as the control mechanism P admits pressure oil to the pipe I84. When the slide plate 205 and reverse lever 2“) 65 are lifted to effect resumption of grinding opera tions, the lugs 215 and H6 will be at the right of the dog I13, but the dog will yield 'to permit pas sage of the lugs as the table moves to the right, which movement is immediately initiated as above described. As previously stated, the rate of travel of the table 15 may be manually controlled by the speed control valve l5l shown in Figs. 13 to 15, and this valve when once set commonly does not re is so moved. ‘ 6. In a grinding machine, a sliding table, dogs on said table, hydraulic table-moving mecha nism, a control and reverse device for said mechanism, a support for said device, means to lower said support so that said device. will clear the dogs, a valve device effective to cause the table to move to reloading position, and a control connection between said support and said valve device. ‘ 65 7. In a grinding machine, a sliding table, dogs on said table, hydraulic‘ table-moving mecha nism, a. control and reverse device for said mechanism, a support for said device, means to lower said support so that said device will clear 70 the dogs, a valve device effective to cause the table to move to reloading position, a control connection between said support and said valve device, and a cam on said support acting to shift said control connection as said support is lowered. ( 6 2,118,189 8. In a grinding machine, a sliding table, dogs on said table, hydraulic table-moving mecha versing valve device to said pressure supply dur nism,‘ a control and reverse device for said means to connect the pressure connection at one ing the time that the machine is in operation, and end or the other of said reversing valve to the and moved by said dogs, means effective to vary exhaust at each end of table travel and thereby . c. partially reduce the pressure at the correspond the extent of working travel of the table result ant from alternate engagement of said device by ing end of said reversing valve andeffect re said dogs while the portions of said dogs which versal thereof. 13. In a grinding 'machine, hydraulic tableengage said device maintain a fixed relation to said table,‘ and means continuously under man ~moving mechanism, a reversing valve device 0 ual controleifectivetooperatesaid?rstmeans to therefor, a pressure supply continuously con nected to both ends of said valve device while the selectively vary the table travel while the ma chine is performing a grinding operation on a machine is in operation, a relief valve for each end of said cylinder, exhaust connections for said piece of work. . relief valves, and means to open a selected relief 9. In a grinding machine, a sliding table, dogs 15 valve‘ at each end of the table travel to effect on said table, table moving mechanism, a con trol and reverse device for said mechanism, said reversal of said travel. said device being alternately engaged device being alternately engaged and 'moved by 14. In 'a grinding machine, hydraulic table said dogs, and'm'anual means to shift said device moving mechanism, a reversing valve ‘ device bodily relative to said dogs and transversely of their path of travel and to thereby vary‘ the therefor, a- pressure supply continuously con so nected to both ends of said valve device while the machine is in operation, a relief valve for each extent of working travel resultant from engage _ ment of said device‘by said dogs. 10. In a grinding machine, a sliding table, dogs on said table, table-moving mechanism, a con trol and reverse lever for said mechanism, and means to shift said lever vertically, said dogs having lever-engaging surfaces slanting downi wardly toward each other, whereby the range of table travel is determined by the vertical posi tion of said lever. _ 11. In a grinding machine, a sliding table, a hydraulic table moving mechanism, a reversing valve device therefor, -a pressure supply, and a manually operated control mechanism effective to expose both ends of said reversing valve device to full pressure during the time that the machine is in operation andalso effective to maintain ‘full pressure at one end of said valve device and to simultaneously connect the other end of said device to the exhaust to relieve the pressure thereon at any point in the table travel and to thereby effect movement of said valve device by which said table is caused to move to predeter mined initial position and to stop‘ in such posi tion. 12. In a grinding machine, hydraulic table moving mechanism, a reversing valve device therefor, a pressure supply and a control mecha 50 nism effective to connect both ends of said re end of said cylinder, exhaust connections for said relief valves, means to open a selected relief valve at each end of the table travel to effect reversal of table travel, and means to, shift the connec tion at onetend of said valve device from pressure to exhaust when the machine is to be stopped and to thereby cause the machine to be stopped in I 30 reloading position. 15. In a grinding machine, a frame, a work vsupporting member, a lifting screw for said mem ber, a cross shaft geared to said screw, a gear ?xed to said cross shaft, an arm loose on said cross shaft, a handle on said arm, a driving ele 35 ment on said arm engaging said gear, and a connection between said driving velement and said handle whereby said driving element may be moved to inoperative position by rocking said 40 handle on said arm. - I 16. The combination in a grinding machine as set forth in claim 15, in which a second gear engages the gear on the cross shaft, and a second arm and handle are connected to turn said sec ond gear, said second arm and handle being avail able for major vertical adjustments of said member. STANLEY W. BATH. ERVIN L. ACKLEY.