US2672835A - Sheet feeding mechanism - Google Patents

Description

March 23, 1954 A. PAUL SHEET FEEDING MECHANISM 2 Sheets-Sheet 1 Filed Jan. 9 1951 INVENTOR. @11 4:

ATTORNEYS.

March 23, 1954 A. PAUL 2,672,835;

SHEET FEEDING MECHANISM Filed Jan. 9, 1951 2 Sheets-Sheet 2 IN V EN TOR.

BY M xwmu ATTORNEYS.

Patented Mar. 23, 1954 UNITED STATES PATENT OFFICE SHEET FEEDING MECHANISM Alex Paul, Elmwood Park, Ill., assignor to Radio Steel & Mfg. Co., Chicago, 111., a corporation of Illinois Application January 9, 1951, Serial No. 205,063

and improved sheet feeding device having safety features for determining the sequence of operations for the purpose of avoiding harm to the operator, material being operated on and to the feed system.

It is an object of this invention to produce a new and improved sheet feeding mechanism which is simple in construction and safe and easy in operation and it is a related object to produce a mechanism of the type described for feeding metallic sheet stock in timed relation with the operation of a processing unit and in timed relation with the position of elements embodied within the feed system.

Another object is to produce a mechanism for advancing sheet stock in stepwise movements into feeding relation with a stamping press and it is a related object to embody means within said .feed mechanism for treating the surfaces of the sheet in preparation for the operations for which it is fed.

A further object is to produce a mechanism for advancing sheet stock onto the bed of a forming machine, said mechanism including means for treating the surface of the sheet as it is advanced.

A still further object is to provide a mechanism of the type described embodying separate mechanism for advancing the sheet through a first portion of its travel while the surfaces are being treated and for receiving said sheet from said first feed portion and advancing it to the bed of the forming machine, and it is a related object to provide means in said mechanism for inactivating the first feed section during operation of More specifically, it is an object of this invention to provide mechanism which is simple in construction and easy in operation for feeding metal sheetstock onto the bed of a metal stamping press, said mechanism embodying separate feed units operating in timed relation with each other and with the press whereby the sheet is advanced through a portion of its travel by one feed section which may embody means for applying a lubricant onto the surfaces of the sheet as it advances the sheet into position for actuation by the second feed unit to the bed of the press in timed relation with the'movemen'ts of the press, the first feed unit and-the second-feed unit operating in timed relation whereby the first is deactivated during the feeding cycle of the second so that a sheet will not be fed thereto while it is out of position.

These and other objects and advantages of this invention will hereinafter appear and for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawings in which- Figure 1 is a schematic view partially in section showing the arrangement of parts in a feed system embodying features of this invention;

Figure 2 is a top plan view partially in section of the first roller feed section shown in Figure 1; and

Figure 3 is an end elevational view of the roller.

feed section.

As shown in the drawing, description herein will be madeto feed mechanism embodying fea-. tures of this invention for advancing sheet stock to a stamping press It having a male mold memher I 5 carried on the under side of an upper platen 12 for up and down movement in molding relation between side frame members 13. The male, mold member cooperates with a stationary female mold member I4 having a cavity M for shaping metal sheets !5 fed between the mold dies. It will be understood that feed mechanism of the type embodying features of this invention.

may also be adapted for use in cooperation with other sheet processing devices adapted to make use of intermittent feed.

The sheet feeding mechanism, ordinarily posit-i tionedin front of the press It, is composed of two separate feed sections, the first of which advances the sheet to the second feed section in timed relation with the operation of the latter. The second feed section advances the sheet the remainder of the distance between the mold dies in timed-relation with the press. The first feed section is adapted to embody means for lubricating or otherwise treating the surfaces of the sheet H as it is advanced therethrough and it is adapted.

to become inoperative while the second feed sec- .7 tion is eifective for advancing the sheet to the would become jammed, as will hereinafter be;

pointed out in greater detail.

The first feed section A. comprises horizontally disposed, laterally spaced base plates 20 and 2| provided with upright side frame plates 22 and 23, each of which is formed with vertically disposed slotted' sections 24; 25 and 26 extending from a substantially equally spaced distance from the bottom of the plate to the upper edge thereof. A top plate 21' extends across the upper edge of each side plate and is fixed thereto, as by bolt members 28. A pair of bearing blocks 39 and 3|, 32 and 33, and 34 and 35 are mounted for floating up and down movement in each of the slots 24, 25 and 26, respectively. The extent of up and down movement is limited by the lower end of the slot and by the top plate 21'.

Each bearing block in one side wall plate is adapted to provide a journal for rotatahly mounting a shaft, the opposite end portion of which is similarly rotatably supported in corresponding bearing blocks in the opposite side wall plate member. For example, horizontally disposed shaft 4c is rotatably journaled in blocks 3&- while shaft 4l is rotatably mounted in blocks 3|, shaft 42 in blocks 32, shaft 43 in blocks 33, shaft 44 in blocks 34, and shaft 45 in blocks 35.

Bearing blocks 3!! and 3! and blocks 34 and 35 are provided with recesses 46 and 41 in substantially the same position in their adjacent upper and lower walls, respectively, for seating coil springs 48 and 49 therebetween which constantly urge the blocks in a direction away from each other when in normal position of use. Heavy coil springs 53 and 5! are arranged so that their lower ends bear upon the upper walls of the upper blocks 3| and 35, respectively, While the other ends seat about a post 52 depending from a disc member 53 of larger diameter than the spring. The disc member is fixed to the lower end portion of a bolt 54 that threadably engages a threaded opening through the top plate 2! so as to permit vertical adjustment of the bolt member relative thereto responsive to turning movement. A bolt head 55 is provided to permit convenient turning movement of the bolt member with a suitable tool and a hold-down nut 6! is provided above the top plate to secure the parts in position of adjustment by tightening the nut 6! down upon the plate 21.

The intermediate pair of blocks 32 and 33 are provided with similar recesses 55 and 51 in their respective top and bottom walls and are additionally provided with posts 53 more effectively to seat a heavy coil spring 59 therebetween which urges the blocks and the shafts j ournaled therein inthe direction away from each other. The top wall of the upper block is engaged directly by the lower end of an elongate bolt member 50 to regulate the distance of separation between the blocks 32 and 33. As previously pointed out, nut members at may be provided in threaded engagement with the bolt 60 to fix the bolt in adjusted position when turned down tightly upon the top plate.

Cylindrical sleeve members formed of metal, hard rubber, plastic or the like, or other substantially rigid material are fixed to or else are formed to be an integral part of the shaft portions disposed between the side plates 22 and 23 to form rollers 62, 63, 64, 65, 66 and El. The center pair of rollers 54 and 65 are formed of larger diameter than the others and are provided with outer jackets 68 and 69 of rubber or absorbent material. The lower portion of the lower roller 68 is partially submerged in a lubricating bath I contained in a pan H located beneath the roller system. Lubricant is transmitted from the lower roller to the upper roller 69 when rotating without a plate l therebetween to precondition the rollers for application of lubricant onto both surfaces of the plate as it passes therebetween.

4 The end rollers are free of the bath and in order to align the bite of the rollers with that of the center pair of lubricating rollers so as to permit the sheet :5 to be advanced in a unidirectional path therebetween, the centers of the shafts 40 and 45, and M; and 45 are spaced farther from the top and bottom of the side plates so as to have a lesser spaced relation therebetween. Spaced blocks 52 and 13 are positioned in the lower end portions of the respective slots 24 and 26 to determine the proper position for the blocks. The roller assembly is enclosed within a cover plate 74 to prevent access to the rollers and to mini mize spray of lubricant into the outside atmcsphere.

The rollers are driven from a power source in the form. of an electric motor it having a driving stub shaft 11 which mounts a sprocket 18. A chain '59 operatively connects the sprocket 78 with another sprocket 80 keyed to the end portion of shaft 44 winch. extends beyond the side plate member 23. in meshing relation causes rollers 66 and 6'! formed on shafts 44 and 45 to turn at substantially the same peripheral speed but in opposite direction. Another chain 83 operates between sprocket 84 keyed to shaft 44 and sprocket 85 keyed to shaft 44] whereby shaft. 40 is caused to turn in the same direction and at substantially the same speed as shaft 44. Spur gears 86 and 87 in meshing relation and mounted onthe end portions of shafts 40 and 4|, respectively, cause the rollers on these two shafts to turn at substans tially the same peripheral speed but in opposite directions. A third chain 38 operatively connects a small sprocket 89 keyed to shaft 40 with a considerably larger sprocket 90 keyed to shaft 32. to cause the latter shaft to turn in the same direction as shaft 30 but at a rate calculated to cause the respective cylindrical sections to turn at substantially the same peripheral speed. Meshing spur gears 91 and 92 fixed to the ends of the shafts 42 and 43 which extend beyond the side plate member 23 cause the shafts and rollers 3 positioned thereon to rotate in opposite directions 54 calculated to effect a frictional grip on the leading edge of the plate 15 as it is advanced into the bite. Lubricating rollers 64 and 65 are constantly urged by spring member 59 in spaced apart relation determined by adjustment by bolt member 60 in an amount calculated to engage the top and bottom surfaces of the plate as it passes therebetween for the purpose of applying lubrieating or coating composition thereto. The dis tance between rollers 64 and 65 with respect to the thickness of the sheet 15 passed therebetween substantially predetermines the amount of lubrieating material which may be applied. Cooperating rollers 52 and t3 operate to advance the sheet in one direction through the first feed section and the pair of rollers 66 and 61 are adapted to grip the leading edge of the sheet being fedbefore the trailing edge has passed through the pair of rollers 62 and 63 so as to maintain a posi-v tive grip at all times upon. the sheet being fed.-

excess lubricant or treating material from the surface of the sheet.

The: second feed section B. located in advance- The pair of spur gears 8i and 82 of the first but in alignment therewith, comprises apair of laterally spaced, horizontally disposed rail members I and IOI supported on top of a suitable platform. The top surface of the rails are adapted to be substantially on the same level as the top wall of the female mold member It and are generally positioned just below the level of the bite between the cooperating pairs of rollers in the first feed section. The sheet being fed drops down onto the rails I 00 and IUI and is adapted to be advanced along the rails into molding relation between the mold dies by a reciprocable pusher mechanism in the form of a pusher rod I02 having two or more upright fingers Hi3 and IMF The upper walls of the fingers are inclined downwardly and forwardly so that engagement with the trailing edge of the sheet dropped from the first feed section will cause deflection of the sheet in a forwardly direction into full engagement with the surface of the rails me and IUI. The sloping portion extends forwardly beyond the front wall I65 of the finger to provide a ledge I06 which prevents inadvertent disengagement with the trailing edge of the sheet as it is engaged by the pusher rod and advanced in feeding relation.

The pusher mechanism is operated in feeding relation and return by a fluid operated piston and cylinder assembly Ill! having a fluid inlet Iilil in the rearward end portion in communication with a master valve I09 by which the inlet is selectively connected to a fluid pressure source or exhaust. Another inlet II!) is provided in the forward end portion of the cylinder and is connected by conduit Ill to the master valve I09 for the purpose of selectively communicating the inlet with the pressure fluid source to which conduit H2 leads or the exhaust I i 3. A regulator valve I It is provided in the conduit I l leading to the first inlet end of the cylinder I Itand a pressure gauge II! is provided to measure same. Finger valve H8 is arranged between the source of pressure fluid and the master valve I09 for the purpose of manually communicating the inlet )8 with the pressure fluid source whereby the pusher arm I02 connected by rod H9 is actuated in a forwardly direction by the piston within the cylinder. Another finger operated valve I is provided for the purpose of causing return movement of the pusher rod I02 by manual adjustment.

For regulating the sequence of operation in timed relation with the movement of the various. elements, a bracket [2! is secured to the edge portion of the upper platen I2 having a laterally ex-" tending plate. I22 pivoted to the upper end thereof. An air valve member 523 having a trip direction in a molding relation but trips the finger I24 during the return stroke. This adjusts the pilot valve N39 to communicate inlet MS with thepressure fluid source and inlet llil with the exhaust so that the pusher rod is advanced. v

"A pilot button valve I25 is fixed tothe front wall of the press in position to be engaged and 5 tripped by the laterally extending end portion I 26 of the arm I I32, or a button attached thereto, when the pusher arm reaches its forwardly most position of adjustment. Actuation of the button valve I25 upon contact with the pusher arm portion I26 has thesame effect as opening valve The pivoted plate I22.

I 2|] in'that the pilotv'alve I69 communicates inlet III) with the fiuid pressure source and inlet I 08 with the exhaust whereby the pusher arm is caused to return immediately to its normal position of adjustment.

A limit switch I21 having a rocking trip finger I28 for regulating energization and deenergization of the electric motor I6 is located in the path of the pusher arm I02 so that the switch finger I28 will normally be urged forwardly into the path of the pusher arm I02 when the arm is out of position but will be deflected downwardly or depressed upon engagement with the pusher arm m2 as it returns to normal position.

When switch arm I28 is in its forwardly position, as when the pusher arm I02 is out of its normal position during operation, the motor 16 becomes deenergized and rotational movement ofv the feed rollers is stopped. When the pusher arm I62 returns to its normal position, the switch arm I28 is deflected rearwardly and the driving motor 15 becomes operative once more for turning the pairs of feed rollers in the first feed section in feeding relation.

In operation, the pusher arm I02 is in its normal rearward position of adjustment where it is able to receive a sheet I5 upon delivery from the first feed section A. When in this posltion,'the switch arm I23 is in depressed position, enabling the motor 15 to be energized for turning the feeding rollers of the first feed section. During such operation, the lower of the lubricating cylinders 64 becomes covered with lubricant and transmits a portion thereof to the periphery of the upper roller 55.

The operator causes a sheet IE to be advanced along a feed table into the bite of the first pair of rollers '62 and 63 which are adjustably tensioned in the direction towards each other to de velop sufficient force for gripping the sheet therebetween and feeding it forward to between the center coating rollers 64 and 85.

i5 therebetween with sufficient clearance to permit application of a uniform calibrated film of lubricant onto both surfaces.

The first pair of feed rollers are adapted to maintain a gripping relation with the sheet I5 at least until the rearward pair of feed rollers 66 and 61 establish a gripping relation with the leading edge thereof and which operate in cooperation with the rollers 62 and 63 or independ-' ently thereof for advancing the sheet I5 through the first feed section and into the second feed section.

In the event that the trailing edge portionof the sheet I5 fails to clear the fingers I 03 and IM, the sloped upper wall I05 deflects the sheet in the forwardly direction so that the sheet may come into full resting relation on top of the rails Thus the sheet is lubricated on both I as and I Ill. surfaces and advanced for feeding into molding relation between the mold dies by the second: feed section B.

As the upper platen I2 completes its molding 1y causes the pusher arm I02'tobe advanced inthe forwardly direction whereby the sheet located a The coating rollers are adjusted, as previously pointed out, by bolt member 60, to permit travel of the sheet canvases on the rails .I I: and I01 and below the ledge I05 of the fingers Hi3 and I04 is slid along the rails into proper position between the mold dies.

When the pusher arm reaches its forward position of adjustment, the end portion I26 actuates the button pilot valve I which operates upon master valve I09 to communicate inlet H0 with the fluid pressure source and inlet I08 with the exhaust so that the piston and the pusher arm I02 are automatically returned to their original, normal position of adjustment.

When the pusher arm I02 starts its forwardly feeding movement and until it returns to start-- ing position, the trip arm I28 is caused to shift forwardly whereby the driving motor 16 is deenergized so that the unidirectionally feeding rollers of the first feed section are inactivated. This prevents sheets frombeing advanced from the first feed section while the pusher arm I02 of the second feed section is out of position. In the event that the motor were allowed to continue to operate while the pusher arm was out of position, it would be possible to feed the subsequent sheet onto the rails while the pusher arm I92 was in advanced position whereby the mechanism would become jammed upon return movement of the pusher arm I02 to its normal position of adjustment.

It will be apparent from this description that I have provided a sheet feeding system particularly adapted for advancing sheet metal stock to the bed of a fabricating unit. The sheet feeding system embodies features adapted to advance the sheet into position for molding in timed relation with the operation of the press, the feed system being divided into a first feed section which also applies a lubricant to the surfaces of the metal sheet and a second feed section adapted quickly to advance the sheet between the mold dies and return so as to provide a more cfiicient feeding relation. It will be apparent from the description that the efficiency of the unit will not be affectedby the slower feed of the first feed section since the operating cycle of the processing unit is a controlling factor but that the second feed section adapted to operate in timed relation therewith provides for rapid movement to make most eillc-ient use of time.

The mechanism embodying features of this invention provides for a sequence of operations which militate against possibility of jamming the equipment and for safety features which minimize harm to operator or equipment.

It will be understood that numerous changes may be made in the details of construction and operation without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. Sheet feeding mechanism for advancing a sheet to a processing unit comprising the combination of a sheet processing unit, a. first sheet feed section and an aligned second sheet feed section to advance a sheet in stepwise fashion by the first feed section to the second feed section and then by the second feed section to the sheet processing unit, unidirectionally rotatable roller means including means for applying a lubricant for the metal sheets onto the rollers for advancing the sheet in said first feed section and coating the surface of the rollers with lubricant, reciprocable pusher means for advancing the sheet by said second feed section, and means responsive to the operation of said sheet processing unit and reciprocable pusher means for. rendering said roller feed means in the first feed sectioninoperative during operation of the reciprocating pusher feed means while the reciprocal pushed feed means is out of normal position for receiving a sheet fed thereto and for rendering said reciprocable pusher feed means operative to advance the sheet in feeding relation upon substanti-al completion of the cycle of operations of the sheet processing unit.

2. Sheet feeding mechanism for advancing a sheet to a processing unit. comprising the combination of a sheet processing unit, a first sheet feed section and an aligned second feed section spaced in advance of and below said first feed section for advancing a sheet in stepwise fashion by the first feed section to the second feedsection and subsequently by the second feed section in feeding relation to the processing unit, unidirectionally rotatable roller feed means ineluding means for applying a lubricant for the metal sheets onto the rollers for advancing the sheet in said first feed section and coating the surface of the rollers with lubricant, reciprocable pusher means for advancing the sheet'in said second feed section including a pusher arm reciprocable between advanced and normal position of adjustment, laterally spaced guide rails over which said pusher arms cause the sheet to be slid during feeding movement, a fluid operated piston and cylinder assembly, and an operative connection between said fluid operated piston and cylinder assembly and said pusher arm for actuating said arm between advanced and normal positions of adjustment, and means responsive to the operation of the processing unit and the reciprocable pusher means for controlling the sequence of operations whereby the roller feed means of the first feed section remains operative while the reciprocable pusher means is in normal position and inoperative when out of position and whereby the piston and cylinder assembly operates to advance the reciproc'able pusher means responsive to substantial completion of the cycle of operations of the processing unit.

3. Sheet feeding mechanism as claimed in claim 2 in which the pusher arm comprises a cross arm having two or more spaced upright fingers formed with an inclined top wall and a hooked end in the upper portion of their forward walls whereby the trailing edge of the sheet as 1t drops onto the second feed section is deflected forwardly upon engagement therewith and is prevented from rising beyond the fingers during advancing movement.

4. Sheet feeding mechanism as claimed in claim 2 in which an electric motor drives the unidirectional roller means of the first feed section and the means for controlling the operation of said electric motor responsive to operation of said reciprocable pusher means comprises a switch member constantly urged to extend into when said switch arm is out of engagement with said pusher arm and capable of energization when rocked upon engagement with the pusher arm in normal position of adjustment.

5. Sheet feeding mechanism as claimed in claim 2 in which the first feed section includes the unidirectionally rotatable roller sheet means and also includes a bath of lubricant in contactwith a coating of lubricant as it is advanced by the rollers in feeding relation.

6. Sheet feeding mechanism as claimed in claim 2 in which the unidirectionally rotatable roller feed means of the first feed section comprises cooperating pairs of rollers positioned to have an aligned bite, the first and last pairs of rollers gripping the sheet therebetween in feeding relation as it is advanced toward the second feed section, a bath of lubricant beneath the feed rollers positioned to be out of contact with the first and last pairs but in which one of the rollers of an intermediate pair is partially submerged therein to apply a coating of lubricant onto the surfaces of the sheet as it is advanced by the roller feed to the second feed section.

7. Sheet feeding mechanism as claimed in claim 6 in which vertically floating bearing blocks mount the pairs of rollers in the roller feed system, means for determining the lower-most position of the bottom bearing blocks, spring means constantly urging the blocks in a direction away from each other, resilient means urging the upper-most blocks in the end pairs of rollers in the downward direction, and means for adjusting the tension of the resilient means.

8. Sheet feeding mechanism as claimed in claim 7 in which means are provided for adjusting the upper limit position of the upper block in intermediate pairs of rollers.

ALEX PAUL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,207,390 Frahm Dec. 5, 1916 1,223,176 Johnson Apr. 17, 1917 1,289,387 Calleson Dec. 31, 1918 1,917,359 Cameron July 11, 1933 1,929,632 Frostad Oct. 10, 1933 1,935,391 Cameron Nov. 14, 1933 1,939,854 Cameron May 22, 1934 2,128,316 Paul Aug. 30, 1938 2,268,298 Pearson Dec. 30, 1941 2,317,440 Cannon Apr. 27, 1943 2,410,694 Tyler Nov. 5, 1946 2,444,544 Thomas July 6, 1948 2,542,303 Bosch Feb. 20, 1951 2,572,472 Griffin Oct. 23, 1951

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