Патент USA US2406821код для вставки
Sept. 3, 1946. vQA. Fox \ 2,406,821 . HEÀT PROCESSING MACHINE File‘d Feb. 20, »1942 4 Sheets-Sheet l mi.muw .u NH NN SHQNNNEN È \. . l (Ittornegs Sept. 3, 1946. 2,406,821 v. A. Fox HEAT PROCESSING MACHINE Filed Feb.< 20, 1942 4 Sheets-Shveet 2 i MW, mm inventor ß Z’Öx Bu Gttcrnegs ‘ Sept. 3, 1946. v_ „_ FOX . ' 2,406,821 HEAT PRÓ-CESS ING MACHINE Filed Feb. 2o, 14942 4 sheets-sheet s 122127 z .13s135. Gttornegs sepf.3,1946.h , " v_ A_ FOX' ` HEAT PROCESSING MÀCHI??? Filed Feb. 20, 1942 2,406,821 , l 4 Sheets-Sheet 4 !_._‘r/ È L`¥4~ à» 17'); ra œ' Q l I n ‘ N .\ !i v t\ ` > Y “ ` l“ _ - y Suventor / g. 'yá . » ‘ê ä 1 G L_) Và ' UL g . We Mm’ . ~ @M2 @LL ttomegs 2,406,821 Patented sept. 3, 1946 UNITED STATES i PATENT OFFICE 2,406,821 1 v ` HEAT PROCESSINGMACHINE vernie A. Fox, Denim, Mich. Application February 20, 1942, Serial No. 432,541 (o1. 34-s6> 6 Claims. 2 1 This invention relates to heat processing ma chines, and in particular to conveyor-type heat lower edge accessible for engagement by other portions "of the machine yet providing an elon processing machines, ` gated central support for several different sizes One object of 'this invention is to provide a heat processing machine for automatically con veying and heat-processing sheets or plates of of sheets or plates. Another object is to provide a heat processing machine as set forth in the preceding objects material such as lithographed plates. » wherein cooling devices are provided adjacent ' the outlet of the machine for cooling the heated sheets or plates being processed by the machine. Another object is to provide a heat processingr machine wherein the sheets of material to be in the drawings: ‘ heated are conveyed in carriers through an oven 10 Figure 1 is aside elevation, partly in section, wherein they are subjected to heated air currents of> the outlet end’of` a heat processing machine proceeding upwardly and downwardly in a zig according to a preferred embodiment of the pres zag path in the opposite direction to the direction ent invention.; of travel of the sheets. , Fig. 2 is a view similar to Fig. l, but showing Another object is to provide a heat processing 15 the inlet end and~ adjacent machinery; machine with an endless conveyor which is nor Fig. 3 is a horizontal section along the line 3-3 mally driven from a source of power which also in 1, with the sheet carriers removed to dis drives other machinery, such as coating and/or close the construction more clearly; printing machinery, automatic means being pro Fig. 4 is a horizontal section similar to Fig. 3 vided for connecting in an auxiliary source: of but taken along the line 4-4 in Fig. 2; power when this machinery ceases operation; Fig. 5 is across section along the line 5--5 in Another object is to provide a heat processing Fig. 1; machine having an oven into which articles‘are Fig. 6 is aside elevation of a portion of a con conveyed upwardly at the inlet and downwardly toward the outlet, thereby conserving heat by -25 veyor `chain `with the sheet -carriers mounted reducing the escape of the heated air normally Fig. 7 is a horizontal section along the line 1--`|A occupying the upper portion of the oven. in Fig. 6; y _ x Another object is to provide aheat processing Fig. 8 is a vertical section along the line 8--8 machine as set forth in the previous object ' wherein means is provided at the outlet end of 30 in Fig. 6; Fig. 9 is a detail view of the clutch shown in the machine for momentarily advancing the the lower central portion of Figs. 2 and 4; lower edge of the sheet faster than the upper ` thereon; ì f Fig. lO is a diagrammatic side elevation of the conveyor at the outlet end of the machine, show 35 ing the means whereby the lower edge of the slicing or buckling. ` ‘sheet or plate is momentarily advanced more Another object is to provide a heat processing rapidly than the upper edge so as to make it fall machine having a travelling conveyor with sheet without injury; . carriers spaced at intervals therealong, these Fig, l1 is a circuit diagram of the electrical, sheet carriers being constructed and arranged with elongated central supports to convey either 40 fuel and air circulation systems. large or small sheets without leaving the lower edge so that when the sheet falls as it nears the end of the conveyor it will not be damaged by edge unsupported at its ends. , Another object is to provide a heat processing General arrangement In general, the heat processing machine of this inventori includes an oven within downwardly culating system and a heating system, automatic 45 inclined ends for conserving heated air which machine including an oven having an air cir means being provided for delaying the starting of the heating system a predetermined time pe riod after the starting of the air circulating sys ‘ is circulated through the oven by fans or blow ers. An endless conveyor moves through the oven and is provided with spaced sheet carriers tem, so that all explosive or inflammable gases at intervals therealong. The sheet carriers con will be automatically cleared out of the oven . sist of open frames (Fig. 5) having gaps at the before heating commences. " bottom thereof to permit engagement of the `sheet , ` i Another object is to provide a carrier forsheets with other conveying apparatus yet having a of material consisting of a framework of Vrods or bars adapted to be carried by a conveyor and mid-portion of the lower edge of a large sheet having provisions for leaving portions of the or >‘the end portion‘of a smallsheet, thereby downwardly depending central supportl for the 3 2,406,821 adapting the conveyor for conveying various sizes ing motor 23 to drive the machines i9, 20 and 2| together with the conveyor I l by the motor 22, or optionally to drive the conveyor I I alone of sheets without changing the sheet carriers. The machine conveyor is normally driven from a main motor which also drives other processing machinery, such as printing and/or coating ma chines. by means of the auxiliary motor 23. The drive from the main motor shaft 24 is conveyed to the shaft 25 of the machine I9 by a belt or chain 26 interconnecting the pulleys or sprocket 21 and Such printing and coating machines are employed where it is desired to imprint a de sign or message upon the sheets, and preferably 28 (Fig. 4). to varnish these, the oven being employed to dry The shaft 25 carries a pulley‘or sprocket 29 the sheets after they have been thus treated. 10 which drives a pulley or sprocket 30 by means An auxiliary motor is also provided for driving of a chain or belt 3|. The sprocket or pulley 3G the conveyor, together with automatically opera- _ ._ vis loosely mounted upon a shaft 32 mounted in tive mechanism which immediately connects the brackets 33 and drives the shaft 32 through a auxiliary motor when the main motor is halted, - A ~ jaw clutch 34. The shaft 32 carries a bevel gear thereby permitting the printing and/or coating 15:. 35 meshing with a bevel gear 36 mounted machines to be operated intermittently while the ’ on a shaft 3l. The latter is connected by conveyor operates continuously over a given pe- *Í -~ lmeans of a jaw clutch 38 to the auxiliary driv_ riod of time. ing motor 23 by means of a sprocket or pulley The spacing of the carriers along the conveyor> 39 mounted loosely upon the shaft 37. The shaft and the mounting of the carriers at their oppo 20 3'!A y,extends lengthwise of the machine and the site ends on a pair of >parallel conveyors enables pulley or> sprocket 39 is driven by a chain or belt the central portions to be maintained compara" 4I from a pulley or sprocket 42 mounted on the tively free from obstructions. Heaters and blow shaft 43 of the auxiliary motor 23. The shaft ers are provided for circulating heated air up 3l ‘also _carries a sprocket or pulley 44 driving ward and downward between the sheets on their 25 a ~sprocketor' pulley 45 by means of a chain or carriers in a zigzag path, this heated air being belt 46. The sprocket or pulley 45 is mounted finally exhausted from the oven by an exhaust upon the input vshaft, 4l of a reduction gear set fan located near the inlet of the oven, thereby 48, the output shaft 49 of which is mounted trans causing the heated air to travel in the opposite versely in the machine frame members 5i] and direction to the conveyor and sheets. An electri 30 carries a pair of sprockets 5I meshing with the cal circuit is provided whereby the heatersare conveyor chains 52. The shaft 3l (Fig. l) is delayed from starting in operation a predeter rotatablyv supported in brackets 53 mounted on mined time after the fans are started, so that the oven supports 54 and upon the outlet sup the latter may remove any inflammable gases port 55, and at its outer end carries a sprocket which may have collected within the oven, there " or pulley 56 driving a sprocket or pulley 51 by by preventing accidental fires or explosions from meansy of-a chain or belt 58. The sprocket or such gases being ignited by the heaters. Cooling pulley 5l is mounted upon the input shaft 59 of fans are provided adjacent the outlet of the ma a?reduction gear set 60, the output shaft 5I of chine for cooling the sheets so that they may be which' carries a pair of sprockets 62 driving the removed by hand if desired. outletïends of the main conveyor chains 63 of An auxiliary conveyor is provided at the outlet the conveyor I l, the inlet ends of which are driven end of the machine for temporarily moving the by thefsprockets 5I upon the shaft 49. The shaft lower edges of the sheets ahead of the upper Sigis likewisely mounted transversely upon the edges, so that as the carriers swing downward at _ outlet frame members E4. The shaft 62 also car the ends of the conveyor the sheets will fall gent 45 ries a‘bair of auxiliary conveyor sprockets 65 ly and without shock, thereby preventing damage to the sheets and possible injury to the machine and operators. A withdrawal conveyor is rpro-~ vided adjacent this auxiliary conveyor for carry Y ing away the sheets as they are unloaded from 50 the oven conveyor. Machine driving mechanism driving the Àsprockets S6 vupon the shaft 61 by means of the belts or sprocket chains 69 of the auxiliary conveyor I3 (Fig. 3). The auxiliary conveyor-shaft 6l is mounted in brackets 69 sup ported upon the outlet frame members 64. The latteralso carry brackets "IG rotatably supporting the shafts ,'II carrying pulleys or sprockets l2 driving the belts or chains 73 of the withdrawal Referring to the drawings in detail, Figs. 1 to _ conveyor I4. The latter is also provided with an 4 inclusive show the heat processing machine of 55 intermediate sprocket- or pulley 'I4 mounted upon this invention as consisting of an oven generally a shaft 15 (Fig. l0)v supported in brackets 'IG and designated I0 containing an endless conveyor gen driving an intermediate belt or chain TI. erally designated II having sheet carriers gener The jaw clutches 34 and 38 are of similar con ally designated I2 mounted thereon and moving struction'in that they arearranged to drive their in an orbital path, An auxiliary conveyor, gen particular shaft in one direction and to slip rela erally designated I3 and a withdrawal conveyor tively thereto in the _opposite direction. Accord generally designated I4 are provided adjacent the ingly a single description sufñces for each of the left-hand or outlet end of the machine (Figs' 1 clutches 34 and`33 (Fig. 9), the clutch 38 being and 3). Air circulation fans I5 are provided for , selectedfo'r'this purpose. The clutch 38 consists circulating air heated by burners I6 through the of a drivingimernber "e8 connected to the pulley spaces between the sheet carriers I2 and in a direction opposite the direction of travel of the conveyor II toward an exhaust fan I -I located near the inlet I8 of the oven I0 (Fig. 2). Also located adjacent the oven inlet `I8 is a printing machine I9, a coating machine >2li and a feeder 2I located therebetween. The machines I9,- ZGand 2l in themselves form no part of the present invention, except as to their main driving' motor 22 which cooperates with an auxiliary driv 39 and having jaw portions 'I9 interconnected by inclined portions 89. The pulley 19 is loosely rotatableup'on "thel shaft 31, and seats against a ,collar- BI `'pinned as at 82 to the shaft 31. Co ‘operatin'g- with the clutch member ‘Ißis a clutch member 83 having driving shoulders or jaws 84 interconnected-by inclined portions 85, the clutch member 83" being keyed or splined to the shaft , 3l' as at 85,) so as_to be slídable longitudinally i along the --shaft'â‘l by means of a spring 8l seated 2,466,821 5 against a collar 88 pinned as at 89 to the shaft 31_ vIn this manner eachl clutch 34 or 38 drives its shaft 32 or 31 in oneÍ direction butslips and clicks withoutfdriving vconnection when the drive is in the opposite direction. " Y ' ` " The purpose of the clutches 34 scribed in connection with‘the operation of the machine, is to perrnîtthe conveyor I I to‘be driven Y normally 'by the main driving motor 22 when the machines |9`and 2|) are in operation, yet to permit the auxiliary driving motor 23 to drive the conveyor II when the main driving motor 22 is halted and the machines I9 and 20 are shut down. bln this way the sheets or plates 9|] (Fig. l0) whichfhave been printed and possibly coated are carried through‘the oven Il) and dried even after the machines I9 and `20 and their driv ing motor 22 have ceased operation. . Oven construction The oven I!! is an elongated box-like structure with side walls 9| (Figures 3 and 5), a-top 92, and a bottom 93. The oven also has inlet and outlet ends S4 and 95 respectively (Figs. 1 and 2). (Fig. `5). The latter areconnected to longitudinal angle members, |24 and also carry spaced longi tudinal members |25 between `which the air may circulate freely. Conveyor and carrier construction `The conveyor II and carriers |2`include the conveyorlchains E3 mounted upon the guide rails H8 and ||l as previously described. rThe con veyor chains E3 consist of links 225 and |21 piv otally connected to` pivot pins |28 carrying rollers |29 <which roll along the~top edges of the guide rails II'I` and I lil. The pivot'pins |23 are pro videdon one side with heads `|29 and on the other side areheld in place by cotter pins |33. Mounted adjacent thelinksIZl are angle members `|3| which extend out over the links |21 and provide rests for the lower edges of the sheets or plates 3|] which form the work pieces handled by the machine. Adjacent the opposite links |25 are mounted channel members |32 having aligned apertures |33 and |34 (Fig. 8) through which pass the side portions .|35 of the carriersl2. These side portions |35 are biiurcated as at |35 and spread apart after their insertion so as to The inlet end 94 for the purpose of conserving 25 prevent their accidental withdrawal. heat is directed downwardly toward the inlet The side portions |35 are bent inwardly to form lil. The inlet end 94 is provided with a port 96 top portions |33 and |31. The top portion |31 communicating with the conduit 91 in a casing ` is bent downwardly in a diagonal portion |38 s3 containing the exhaust-fan I1 for creating a (Fig. 5) `to the portion |35 in any suitable way, suction to remove air which has traversed the 30 as by sp-ot welding; The top portion |38 is bent oven and to discharge this air into the discharge ‘ diagonally downwardly in a portion Mb which conduit 99. is secured at lthe top portion le! to the diagonal The outlet end 95 of the oven I 0 (Fig. 1) is portion |38. A diagonal portion |22, also secured provided with an outlet |00 communicating with at the top portion |l|3 to the diagonal portion a hood or vestibule IGI likewise for the pur 35 §38, continues downwardly to a junction at the pose of conserving heat and minimizing the escape of the heated air. Bañies |62 are distributed at intervals along the interior of the oven Iii for impeding the direct passage of the air from one end of the oven to the other so as to force it' - downwardly between the sheets 96 as they are carried along by the conveyor II upon »the car riers I2. One of the walls 9| of the oven is pro vided with doors HB3 for permitting access to thel burners I6 and other portions of the interior of the machine. v ‘ a The burners I6 are shown as gas burners but other types may obviously be employed. The~ air heated by the burners is circulated by the fans or blowers I5, which are 'located in casings | |14 having inlets or intakes IBEAandoutlets or ex top portion |44 with the other side member |35. Secured at its opposite ends M5 to the diagonal members |38 and |62 is a vU-shaped downwardly extending frame |46 having side portions |41 and a cross portion >Idd at thebottom thereof. Secured to the bottom portion M8 at the corners oi the frame lli@ are sheet'supports léi‘el. The sheet supports are inclinedupwardly as at Mila (Fig. 6), and `serve to support the lower edges of thesheets 9d. j , The carriers i2 are ,thus‘spaced at `intervalsy along `therchain 63 and are inclined upwardly »so that the sheets or plates di! rest in inclined posi tions’as they travel through the oven (Fig. 6). The downwardly extending `frame its with its supportsk |49 enables sheets smaller than theV maximum size sheets to be conveyed, hence there hausts |06. The blowers I5 are operated by shafts Ic'imounted in brackets |08 (Fig. 5) secured to is no necessity for changing the carriers l2 for the walls 9|. The shafts |û1 carry pulleys |69 diiierent sizes of sheets. Moreover, the open 55 driven by belts III) from pulleys III upon the spaces between the side members £35 and |46 shafts I I2 of motors I I3. The latter are mounted permit the lower edges of the plates to be engaged upon brackets I I4 beneath the longitudinal frame by the auxiliary conveyor 65| (Fig. l0) which members II5 interconnecting the oven supports 5d. The brackets I|4 are also matched by corre-- sponding brackets i IB on'the opposite side of the machine (Fig. 5) and these together support the angle guide rails ||1 upon which the conveyor chain E3 travels on its return path. » " The'interior oi the oven is likewise provided with angle guide rails I i8 which support the con veyor 53 in its travel through the oven, and these guide rails `I Ill` are inclined downwardly at the opposite ends ofthe oven. Cooling fan motors H9 provided with fans |20 incasings |2I are passes through these spaces and serves to advance the lower edges of the sheets 9S ahead of their upper edges as previously described above. ` Heating, driving and air circulating systems` ` Figure 11 shows diagrammatically the system whereby the various motors are energized and the various burners and blowers controlled, The system consists broadly of an electrical circuit for` energizing the various blower motors |1, I I3 and IIB, a fuel `supply system consisting of piping located near the outlet end 95 of the oven so as 70 controlled by a magnetically operated master valve and magnetically operated burner valves, to cool the sheets or plates 90 as they emerge and an electrical safety circuit controlled by ther from the vestibule or hood |!.'||. mostatic switches so that the gas burner valves Near the oven outlet Icll the guide rails II8 remain open only while the temperature is high are supported by a cross member 22 and else where within the oven by cross members |23 755 and close when the‘temperature drops. A tirne~ 2,406,821 7 delay relay inserted in the circuit of themaster magnetic valve delays the opening of this valve until the blower motors I|3 have been in oper Thus, when the blower motors I|3 are operated, the'contactor switches |92, |93 and|94 close and the switches 200 likewise close to permit ation a predetermined length of time so as to clear the oven of inflammable or explosive gases before the burners can be ignited. current to energize the time-delay relay 203. of the oven of all explosive gases. Leading from the power lines |54, |55 and |56 are auxiliary pursue its orbital path through the oven I0 and >After the latter has run through its cycle, it ener gizes the operating coil of the gas supply valve In particular, the electrical system consists of |68 through the lines 205 and 206 opening this power current supply lines |50 to |52 having a normally closed valve. Thus, gas is not admitted single throw switch |53. This controls the ener to the gas line |69 until the blower motors ||3 gization of the blower motor energization lines 10 have been operating a predetermined time. |54, |55 and |56 leading to the blower motors Operation I|3 and I|9 and also to the exhaust fan motor I1. Consequently when the switch |53 is closed, In the operation of the machine of this inven the blower motors I1, ||3 and ||9 start in oper tion, the main and auxiliary driving motors 22 ation, permitting the blowers to clear the interior and 23 are energized to cause the conveyor I| to also to drive the printing press I9 and coating machine 20. The switches |53 are then closed, energizing the blower motors I1, | I3 and I I9, and air compressor I 6I. The latter has an intake 20 causing air to flow through the oven in a cir |62 and a discharge conduit |63 leading by branch cuitous path opposite the direction travel of the lines |64 to electrically controlled proportional conveyor II. The baiiies |02 cause the air to mixers |65. The branch lines |64 contain manual move up and down between the carriers I2, so air valves |66. that the air follows a zigzag path as indicated Fuel gas is supplied to the proportional mixers 25 by the arrows in Figures 1 and 2. |65 from the gas supply line |61 by way of the The operator now closes the switches |9| and magnetically operated valve |68, the gas supply |84 to energize the control circuit. The air oper line |69, the branch lines |10, the manual gas ated valves 200 then close under the influence of valves I1| and the magnetically operated gas the blast of air from the blowers, thereby closing valves |12. From the proportional mixers |65 30 the circuit to the time-delay relay 203 through the conduits |13 lead to the burners I6. Asso the contactor switches |92, |93 and |94, which ciated with each burner I6 is a thermocouple |14 have been closed since the blower motors II3 which generates current when it is heated by were energized by the closing of the switch |53. the burner I6. This current is conveyed through After a predetermined time, the gas valve I 68 the lines |15 and |16 to the operating coil of the 35 opens after being energized by the time-delay re normally closed gas valve |12 to maintain it open lay at the end of its cycle and fuel gas passes power lines |51, |58 and |59 for energizing the air compressor motor |60 which operates the while the burners I6 are alight but to permit the gas valves |12 to close when the burners are not from the conduit |61 into the conduits |69 and |19, Meanwhile, air has been supplied by the lighted. The normally closed magnetic valves compressor |6| to the conduits |63 and |64 lead |12 are provided with manually operated valve 40 ing to the proportional mixers I 65. It is, of members |11 by which the valves |12 may be course, assumed that the manual valves |66 and manually opened when the burners I6 are ignited. I1I have been opened. The proportional mixers I 65 are under the con The operator now opens the normally closed trol of thermostatic bulbs |18 connected by the gas valves |12 by pressing upward 0n the valve lines |19 to the temperature control instruments members |11, permitting gas to flow from the |80 which in turn are connected by the lines conduits |10 into the proportional mixer |65. |8I, I 82 and |83 to the proportional mixers |65. The motors of the latter have been energized The latter are likewise under the control ofthe through the lines |85 and |86 by the closing of switches |84 connecting the lines |85 and |86 the switches |84, and consequently mixed gas is to the lines |81 and |88. The lines |81 and |88 50 suppliedto the burners I6 through the conduits are energized from the current supply lines |89 |13. The operator lights the burners I6, holding and |90 under the control of the single throw up the valve members |11 manually until the switch ISI. heating of the thermoccuples |14 generates The electrical circuit (Fig. 11) includes the enough current to energize the operating coils contactor switches |92, |93 and |94 having oper 55 of the magnetic gas valves |12, a suñicient ating coils |95, |96 and |91 respectively con amount to hold them open. If the temperature nected either to the power lines |54 and |56 or to rises and falls in the oven, the thermostatic bulbs the power lines |51 and |59. The contactor |19 and the temperature control instruments |80 switches I 92, |93 and |94 are normally open, and so regulate the proportional mixers |65 that the are closed by the energization of their operating 60 ratio of air to gas remains the same while the coils |95, |96 and |91 in response to the closing volume is varied in order to maintain a substan of the switch |53. The latter, when closed, ener tially constant temperature within the oven I0. gizes the blower motors I I3 and causes the blow In the meantime, the printing machine |9 and ers to operate. coating machine 20 have been imprinting designs Running from the current line |88 is a line | 98 65 on the sheets 20 of tin or other material, and which continues in the line |99 beyond the con these have been deposited upon the carriers I2 as tactor switch |92. The line |99 is provided with the conveyor II moves them through the oven. a series of normally-open air-responsive switches The heated air circulates in a zigzag path through 200 which are closed automatically when the the spaces between the carriers and the sheets, blower motors | I3 are operating, thereby permit 70 and follows a general direction opposite to the ting current to be transmitted to the contactor direction of travel of the conveyor II, due to the |93, thence through the line 20| through the con tactor |94 to the line 202 leading to the time delay relay 203, from the opposite pole of which a line ‘204 leads to the current supply line |81. operation of the exhaust chain 98. As the sheets or plates 90 emerge from the vestibule |0|, they are cooled by the drafts of cool air coming from the cooling fans |20 operated by the motors |I9. 2,406,821 White the carriers“ I2 move over the‘auxilîary ranged inseries with`their intakes toward said conveyors 68, the latter extend into'fthe'spaces in the bottom edges of the carriers l2,engaging 'oven outlet and with their exhausts toward said voven inlet, said blower exhausts having upwardly directed baille portions disposed between adja the bottom edges of the sheets 9D; Since the aux iliary conveyors Bâ are moving more rapidlythan the main conveyor chains 63, the bottom edges of the sheets or plates lill are moved ahead of their top edges (Fig. 1G) so that ¿as the carriers I2 cent blowers whereby to move heated air along a vertical zigzag path in a direction opposite to the direction of conveyor travel,- one of said blowers being positioned adjacent said inlet end to directa blast of air thereacross and form an the sheets @il lie flat against the back of each 10 air wall thereatfand an exhaust fan disposed in swing downwardly around the shaft 62`-as an axis, carrier, until they arrive at the withdrawal "con veyors 'E3 and l1. The latter conveyors then con vey the sheets to thenextfstagebf operations such as the forming oi"V cans from the sheets. one of the walls of the inclined inlet end to re move combustible gases fro-m said oven. "3. In `a heat processing machine, an elongated oven.~having downwardly inclined inlet and out If at any time the gas supply is‘accidentally 15 let- ends with ia substantially horizontal inlet, a interrupted, the thermocoupl'es VM1 immediately cease to generate current and the magnetic valves l’lâ automatically close. This cuts off the supply of gas to the burners It which cannot thereafter be lighted until the switches |12 are manually 20 opened as previously described, Meanwhile, the auxiliary driving motor 23 has also been operat ing but it has failed thus far-to drive the shaft 3l since the automatic body clutch 38 prevents this by the slippage of the clutch members 18 and 83 relatively to each other (Fig. 9). `conveyor movable upwardly through said inlet end ‘and through said oven, a series of ‘racks ar ranged on said conveyor for supporting sheet ma terial onv edge during its passage through said oven and in a substantially horizontal position ‘ during its passage through said inlet, heating means in said oven, a plurality of blowers be neath said conveyor arranged in spaced apart re lation for directing blasts of heated air upwardly through said conveyor and between said sheets of material, de?lector means mounted 0n the roof of the oven for directing said heated air in a downward direction toward the intake of an ad jacent blower, means for driving said blowers, If now the desired quantity of sheets or plates have been printed and coated and the main driv ing motor 22 is shut down to halt the machines I9 and 20, the shaft 25 and the pulley or sprocket 30 means for driving said conveyor, and an exhaust fan disposed in one of the walls of the inclined til immediately come to restl Due to the provi inlet end for removing combustible gases from sion of the automatic jaw clutches 34 and 3Q, said oven. however, the auxiliary driving motor 23 now 4. In a heat processing machine, an elongated drives the shaft 3l through the jaw clutch 33 _oven having downwardly inclined inlet and out while the clutch members of the jaw clutch 34 slip let ends with a substantially horizontal inlet, a relatively to each other. conveyor movable upwardly through said inlet While a specilic embodiment of the invention end and through said oven, a series of racks ar has been described and illustrated, it vwill be ranged on said conveyor for supporting sheet understood that various modifications may be made within the scope of the appended claims 40 material on edge during its passage through said oven and in a substantially horizontal position without departing from the spirit of the inven during its passage through said inlet, heating tion. means in said oven, a plurality of blowers beneath What I claim is: said conveyor arranged in spaced relation, for l. In a heat processing machine, an elongated directing blasts of heated air ,upwardly through oven having a downwardly inclined inlet end said conveyor and between said sheets of ma with a substantially horizontal inlet, a conveyor terial, deflector means mounted on the roof of movable upwardly through said inlet end and the oven for directing said heated air in a down through said oven, rack members carried by said ward direction toward the intake of an adja conveyor for supporting sheet material on edge cent blower, means for driving said blowers, while being conveyed through said oven and to means for driving said conveyor, and an exhaust extend transversely of said inlet end and par fan disposed in one of the walls of the inclined tially close said inlet, heating means in said inlet end for removing combustible gases from oven, a series of blowers arranged beneath the said oven, said blowers being arranged t0 create conveyor in said oven for directing heated air upwardly between said conveyor and the sheet 55 a forced draft from one end of the oven to the other in a direction opposite to the direction of material thereon, one of said blowers being dis conveyor movement. posed adjacent said inclined inlet end 'to direct a 5. In a heat processing machine, an elongated blast of heated air transversely thereacross, and oven having-downwardly inclined inlet and outlet an exhaust fan disposed in one of the walls of said inclined inlet end for removing combustible 60 ends with a substantially horizontal inlet, a con veyor movable upwardly through said inlet end gases from said Oven. , and through said oven, a series of racks arranged 2. In a heat processing machine, an elongated on said conveyor for supporting sheet material oven having downwardly inclined inlet and out on edge during its passage through said oven and let ends with a substantially horizontal inle't, a conveyor movable through said inlet end and` ~ in a substantially horizontal position during its passage through said inlet, heating means in said along said oven with the lower course thereof oven, a plurality of blowers beneath said con returning to said inlet end externally of said veyor arranged in spaced apart relation for di oven, a series of racks arranged on said conveyor recting blasts of heated air upwardly through for supporting sheet material on edge during its travel through said oven, said racks being ar 70 said conveyor and between said sheets of mate rial, deflector means mounted on the roof of the ranged to support the sheet material in a sub oven for directing said heated air in a downward stantially horizontal position during its passage direction toward the intake of an adjacent upwardly through said inlet end. to partially close blower, means for driving said blowers, means said inlet, heating means located in said oven, a for driving said conveyor, and an exhaust fan plurality of blowers beneath said conveyor ar 2,406,821 ll disposed in one of the' walls of the inclined inlet end for removing combustible gases from said oven, and fan means mounted in close proximity to said outlet for directing a blast of cool air upwardly between said sheets of material as they pass from said oven. 6. In a heat processing machine, an elongated oven having downwardly inclined inlet and outlet ends with a substantially horizontal inlet, a con t 12 recting blasts of heated air upwardly th‘rough said conveyor and between said sheets of ma terial, deflector means mounted on the roof of the oven for directing said heated air in a down ward direction toward the intake of an adjacent blower, means for driving said blowers, means for driving said conveyor, an exhaust fan disposed in one of the walls of the inclined inlet end for removing combustible gases from said oven, said veyor movable upwardly through said inlet end 10 blowers being arranged to create a, forced draft and through said oven, a series of racks arranged from one end of the oven to the other in a direc on said conveyor for supporting sheet material on tion opposite to the direction of conveyor move edge during its passage through said oven and ment, and fan means mounted in close proximity in a substantially horizontal position during its to said outlet for directing a blast of cool air passage through said inlet, heating means in said upwardly between said sheets of material as they oven, a plurality of blowers beneath said con veyor arranged in spaced apart relation for di pass from said oven. VERNIE A. FOX.