US3315553A

US3315553A - Stock feeding and blank ejecting apparatus for punch presses

Info

Publication number: US3315553A
Application number: US396866A
Authority: US
Inventors: Milton E Handler; Irwin J Ferdinand
Original assignee: Hirsh Manufacturing Co SA Co
Current assignee: Hirsh Manufacturing Co SA Co
Priority date: 1964-09-16
Filing date: 1964-09-16
Publication date: 1967-04-25
Anticipated expiration: 1984-04-25

Description

April 1957 M. E. HANDLER ETAL 3,315,553

STOCK FEEDING AND BLANK EJECTING APPARATUS FOR PUNCH PRESSES Filed Sept. 16, 1964 4 Sheets-Sheet 1 FIG! INVENTORSZ MILTON E. HANDLER IRWIN J. FERDINAND April 1957 M. E. HANDLER ETAL 3,315,553

3? i 32 M W" "In 32/ 324 s ll MILTO E. HANDLER April 25, 1967 M. E. HANDLER ETAL 3,315,553

STOCK FEEDING AND BLANK EJECTING APPARATUS FOR PUNCH PRESSES Filed Sept. 16, 1964 4 Sheets-Sheet 5 FIG. 4

INVENTORS:

MILTON E. HANDLER IRWIN J. FERDINAND A ril 25, 1967 M. E. HANDLER ETAL 3,315,553

STOCK FEEDING AND BLANK EJECTING APPARATUS FOR PUNCH PRESSES 4 Sheets-Sheet 4 Filed Sept. 16, 1964 INVENTORS: t 1 a] MILTON E. HANDLER IRWIN J. FERDINAND United States Patent 3,315,553 STOCK FEEDING AND BLANK EJECTING APPARATUS FOR PUNCH PRESSES Mllton E. Handler, Evanston, and Irwin J. Ferdinand,

Gleucoe, Ill., assignors to S. A. Hirsh Mfg. Co., Slrokie,

111., a corporation of Illinois Filed Sept. 16, 1964, Ser. No. 396,866 14 Claims. (CI. 8382) The present invention relates to a shelf forming and handling apparatus and particularly to the handling of strip stock fed at a constant rate from a coiled sheet steel supply roll and operated upon by a punch press running at a constant rapid speed to produce shelf blanks 1n which the feed at the stamping dies is alternately retarded and accelerated and the blanks are discharged more rapidly than the acceleration.

While the invention is applicable to the feeding of stock to and the ejection of blanks from punch presses which are designed for a Wide variety of forming operations and in the provision of blanks for producing a wide variety of articles, the invention has, for exemplary purposes, been illustrated and described herein in connection with the production of sheet steel blanks the length of which is the width of commercially supplied unslit or mill-edge prefinished coiled steel. The apparatus herein described is preliminary to ultimately forming the blanks into generally rectangular shelves, marginally reinforced on all four sides, and adapted at their corners for squared attachment to corner posts in the assembly of knockdown steel shelving units. An example of such an apparatus has been shown and described in our copending United States patent application, Ser. No. 390,647, filed Aug. 19, 1964, and entitled, Shelf Handling and Forming Apparatus, of which application the present one is a companion application.

Heretofore, in punch press feeding operations where high speeds are desired and Where the length of the blank in the direction of feed is relatively great, for example in excess of twelve inches, the number of blanks which may be formed over a given period of time, have been governed by two principal considerations, namely the maximum speed at which the coiled steel may be fed with intermittent longitudinal movement of the stock from the roll into the punch press by a reciprocating feed arm, and the maximum speed at which the blanks may be formed and ejected from the working area of the press, whichever is the slowest. The leading edge of the coiled steel must traverse the entire distance of the working area of the press before the press platen is permitted to cycle so that the presence of a full complement of sheet metal will be assured between the dies for the punching of a full size blank at each stroke of the press platen. Likewise, after each punching stroke it is desirable that the blanks be ejected from the working area of the press with sufficient rapidity of body movement that they will cause no interference with the incoming leading edge of the coiled steel that is being moved into position for the production of the next blank. Where the blanks undergoing punching are of appreciable length in the direction of feed movement, the speed of operation of the press is limited by the length of time it takes for the leading edge of the coiled steel to move across the working area and into position beneath the upper punching die and generally the press cycle must pause until tripped each time.

Where a punch press is fed from coiled steel, it is necessary that the sheet steel be straightened to remove the residual curvature before it enters the working area of the punch press. Otherwise the blanks will not lie flat on the die. For this purpose straightening rolls are required and, when such rolls are employed for feeding the coiled steel directly to the punch press, it has heretofore been considered necessary to utilize an intermittent feed to stop the progress of the sheet metal through the rolls at the time that the press performs its actual punchmg operation and until such time as the blank has been e ected from the working area of the press to make room for new material during the next succeeding press cycle. This has required intermittent operation of the straightening rolls or other feed devices, and in turn, this has involved the use of numerous operating instrumentalities such as braking means for periodically stopping the operation of the straightening rolls during each press cycle, and complicated electrical control instrumentalities and timing devices for effecting proper intermittent operation of the feeding mechanism.

Stated otherwise, where intermittent feeding of the stock to the punch press has been required, an appreciable portion of each press cycle is consumed by a period of idle time while the press waits, so to speak, for a full introduction of metal to the working area. Similarly, an appreciable portion of each feeding cycle is consumed while the feeding mechanism awaits the punching operation and the subsequent ejection of the punched blank from the working area of the press.

The present invention is designed to overcome the above noted limitations that are attendant upon the construction and use of conventional punch presses and feeding apparatus therefor, particularly where relatively large blanks are concerned. Accordingly, the present invention contemplates the novel combination of a punch press and feeding apparatus therefor wherein the punch press is run at its full speed and is fed steel directly from a continuous running coiled steel roll through continuous running straightening rolls.

The provision of such a novel combination of a punch press and feeding apparatus constitutes the principal and general object of the invention and in carrying out this object the invention contemplates the novel recurrent accumulation and release of a major portion of the feed material under flexure stresses in a region close to the punch press dies, between the straightening rolls and the dies, during the time beginning with the completion of a previous fee d advance and ending after the press has performed its operative power stroke and has started ejection of the resultant blank from the Working area. Thereafter the accumulated material is self propelled by the flexure stress across the working area of the press with great rapidity, just short of reaching the feed stop whereupon the continuing feed on the part of the straightening rolls moves the material the remaining distance gently to the feed stops in time to trip and keep the press cycle in continuous operation without interruption. By such an arrangement, the continuously operating straightening rolls have no period of idle time nor any stop and start inertias to overcome and they continue to feed the coiled steel forwardly during the time that the punch press performs its operative stroke and during the subsequent ejection of the punched blank from the Working area of the press Without any danger of marring prefinished stockor damaging or bouncing the feed edges of the stock.

It is another and important object of the invention to provide an apparatus of the character briefly outlined above which is devoid of timer controlled operatrons. All punch press and feeding operations take place m a continuous process in their proper sequential order under the check control of the movements of the coiled steel up to the time the blanks leave the working area of the punch press. provided whereby each succeeding operation, whether it be a stock feeding operation or a punch press operation, is cleared for performance by the proper completion of the next preceding operation long before the performance In carrying out this object, novel means are begins whereby controls provided are relegated to function as safety stops and not start controls.

Another and similar object of the invention is to provide' a cyclicly operable apparatus wherein the proper completion of the last operation, namely the complete 7 ejection of a blank from the working area of the punch press, enables uninterrupted regular recurrency of the first operation in the-next cycle, namely the movement of new stock into the .working area of the punch press. Thus the v apparatus is fully automatic and repetitive in its operation and, within the speed limit of the punch press, will continue to operate indefinitely in the high speed production of blanks with a full feed rate of the feed stock, yet'as V a 'further'object of the invention can be controlled at will merely by varying the feed rate of the feed stock to bring Numerous ancillary objects, too numerous to mention at this time, will readily suggest themselves as the nature.

of the invention is'better understood. Thes'ecobjects re- I late to various instrumentalities which are employed for handling either the coiled steel or the blanks which are stamped therefrom, as well as to certain combinations thereof and the control mechanism by means of which in the Working area. The switch associated therewith not only clears the punch press for securement operation without stopping after a preceding operation but also to actuate a clamping mechanism which arrests further feed 7 pressure of the coiled steel upon the stops and allows the aforementioned accumulation of material to take place for use during the next succeeding press cycle. Theinvention further embodies novel 'means' whereby movement of the press ram initiates ejection of'the punched.

blank from the working area of the press on its back stroke 'well before reaching the 'point for. starting its work stroke in a manner that is also novel in that such ejection is completed before the starting point or the ram is reached. Furthermore, the arrival of the ejected blanka-t a point outside the working area'of the press initiates a control function whereby the aforementioned clamping mechanism is released and the blank-ejecting mechanism is retracted simultaneously to place the apparatus in condition for the nextpress cycle,.and with the release of the clamp the coiled steel under" accumulated length and energy shoots across the 'working area to Within an inch or two of the feed stop to be moved the remaining distance at slow feed against the feed stop before the movement of the ram passes a check point at which t can be stopped bythe feed stop switch if there ji s an error in the feed.

the apparatus to a slow motion for study or checking the sequencing operation of the apparatus. 7

7 4 a part of this specification, one illustrative embodiment of the invention has been shown.

FIG. 1 is a perspective view, entirely schematic in its,

representation, of a shelf forming and handling apparatus embodying the stock feeding and blank ejecting apparatus of the present invention; 7 I

FIG. 2 is a perspective viewof oneexemplary form of a marginally reinforced shelf constructed by the apparatus of FIG. 1; I

FIG. 3 is a plan view of a blank from, which the shelf 7 of FIG. 1 is formed; and r i FIGS. 4 and 5, when positioned in s1de-by-srderelatronship, represent a schematic side elevational view of the stock feeding and blank ejecting apparatus, the'view enl bodying a circuit diagram of the control instrumentalit es associated with the'invention; 1

Referring now to the drawings in detail and in particular to FIG. 1, there has been disclosed in this viewiin an entirely schematic manner, anapparatus for forming steel shelves such as the shelf 10jshown at the extremeright hand end of the view and also in FIG. 2. Wrhile'the apparatus is adapted, by modification or interchange of certain forming rolls associated therewith, for the constr'uction of a wide variety'of generally rectangular shelves, the shelf 10 has been selected for illustration herein as being exemplary of at least one particular shelf configuration capable of beingeflectively formed by the apparatus.

The present invention is concerned primarly with the stock feeding and blank ejecting arrangement which appears at the left side of FIG. 1 and which embodies cer-.

tain straightening rolls which also continuously advance I the feed stock, a punch press for severing the blanks from the stock fed to the working area, and an intermediate gatheringstation, hereinafter referred to as the hump leading edge of .thefeed stock is held back by a clamping mechanism from the working area when the press ram is working. This accumulation of feedstock isgathered' in the form of a bulge or hump---between the straightening rolls and the punch press and,.when the clamping mechanism releases its hold on't-he web, the hump is The means whereby the above briefly outlined functions 7 V are accomplished may vary without departing fromthe scope of the present invention. For example, electric,

pneumatic or hydraulic power may be employed for actuating many of the instrumentalities associated with the fthe invention, electric power has been employed exclusively for supplying power to these operating instrumentalities inasmuch as the electrical control devices for effecting actuation thereof are not appreciablyaltered from products purchased on the market. 7 r

' In the accompanying three sheets of drawings forming forcibly collapsed, thus projecting the leading edgeof the feed stock forwardly and 'rapidlyacross the working area of the press.

The shelf It is of the type shown and describedin a :copending application of Irwin J.-Ferdinand and Dale R.

"Lopatka, Ser. No. 368,634, filed May 19, 1964, and entitled, Knockdown Steel Shelving Unit and Corner Fastening Means Thereforj? and reference may be had to r i such application for a full understanding of thenature of the shelf and of its use Briefly, however, the shelf is de-I signed for use in a plurality of differentlsizes in conjunc- "tion with'o th er shelves of like sizegin connection with" knockdown steel shelving wherein, the shelves are remova'bly secured at their corn'ersto vertical corner posts.

The shelf 10 is generally of rectangular configuration and it includes a horizontalplanar body portion 12 hav ing downtumed longitudinally extending marginal come pound side flanges. 14 and 'downturned transversely ex tending marginal compoundlendflanges 16. Th'esiddflanges 14 are provided with narrow inturned rim flanges i 18 which terminate in upturned 'reentrant' flanges 20." The end flanges 1 6 are provided with narrow inturned flanges 22. The upper edges: of the flanges 14' project above the plane of the body portion 12 and are connected 7 'notched out as at 28, thus exposing the squared ends of the

flanges

14 and 16 at the notches for reception therein of a corner post (not shown) by means of which the shelf 10 may be assembled in a shelving unit,'all'in=-a manner set forth in the above mentioned copending application. The shelf is adapted to be formed by the apparatus of FIG. 1 from a blank such as the blank (FIG. 3), this blank being of rectangular design and having notched corners 32 which establish the previously mentioned notched out corners 28 of the completed shelf 10 when the shelf is in its final form.

The shelves 10 are successively formed from finishcoated mill run coiled steel (FIG. 1) which passes through straightening rolls 41 and from thence to a punch press 42 where the notched blanks 30 are formed. The notched blanks are then ejected laterally and conducted endwise, i.e. in their long direction, along a conveyor section 44 to a first mill 46 where the elongated narrow strip portions 34 thereof are operated upon by a series of successive forming rolls to produce the

marginal side flanges

14 and 16, these flanges being turned downwardly out of the plane of the blank by the rolls. Due to the relatively great length of the strips in their direction of travel, little or no difficulty is encountered in blank alignment with the forming rolls and the blanks can be formed at a high rate of speed by continuous running rolls.

From the first forming mill 46, the blanks are then conducted to a blank-inverting and direction-changing device in the form of a rotary rack 50 having radial arms 52. These arms receive the blanks and invert them by flipping them over onto a rapid conveyor 54 then to a second conveyor 56 driven in timed relation with a second mill 60 which receives the blanks and by means of which a series of successive forming rolls, operates upon the short strip portions 36 and shapes them into the form of the flanges 16, thereby completing the finished shelf 10.

The disclosure of FIG. 1 being entirely schematic, no attempt has been made herein to disclose all of the blank handling devices and instrumentalities associated with the machine other than those briefly mentioned above. As previously stated, this invnetion is essentially concerned with the operation of the punch press 42, the feeding of coiled steel to the press, and the ejection of blanks from the press, all in a manner and for a purpose that will now be set forth in detail.

Referring now, additionally, to FIGS. 4 and 5, and placing these views in edge-to-edge relationship so that they will constitute a circuit and mechanical diagram of the punch press feeding and blank ejecting mechanism of the present invention, the coiled steel 40 issues from a free floating drum 62 in the form of a web 64 which is conducted to the straightening rolls 41 of a web straightening apparatus 66 Where the residual curvature of the coiled steel is removed in the usual way of progressive reverse flexing. The rolls are continuously driven from an electric motor M1 and thus the straightening apparatus 66 establishes a web feeding station 67 along the linear path of movement of the web 64 preferably at a speed that can be varied by V-belt pulley adjustment or ratios depending on the width of the shelf, i.e., the length of the feed stock cut 05 by the press each stroke; The narrower the width the slower the feed rate.

The web 64 issuing from the straightening rolls passes to a hump table 68 over which it normally slides in a forward uphill direction leading to the punch press 42. The upper surface of the hump table is generally of an arched or sinuous configuration, its curvature representing a relative flat portion of a sine wave. The upper surface of the table has a low trough portion 70 at its rear end, a raised crest portion 72 at its forward end and an intervening upwardly and forwardly inclined ramp surface 73. The web 64 is shown in full lines in its normal position wherein it is almost in flush contact with the upper surface of the table coextensively therealong and, when in such position, the web is pushed forwardly along the table under the drive of the straightening rolls which move the web forwardly with an edgewise compressive force. A crossbar 74 overlies the rear low portion 70 of the table and is provided with a felt or other soft liner 76 so that the upper 6 surface of the web will not become damaged by frictional contact therewith. A similar crossbar 78 overlies the forward high portion of the hump table 68.

The hump table 68 is provided for the purpose of causing the material of the web 64 to be progressively gathered or accumulated in the form of a gradually rising bulge or hump, such as has been shown in dotted lines in FIG. 4 and designated at H, when the forward leading region of the web is restrained against forward movement, the material of the hump being accumulated and held in reserve for forward projection by collapse of the hump when the restraining means is discontinued, all in a manner and for a purpose that will be made clear presently. The hump table thus establishes a web gathering and accumulating station 79 along the path of travel of the web 64. The curvature of the upper surface of the hump table 68 is conducive toward creation of the hump H and it contributes toward the proper shaping of the hump. Inasmuch as the terminal crest portion 72 is disposed at a higher elevation than the initial trough portion 70, when the material resting on the hump table 68 is placed under compression by the feeding action of the straightening rolls 41 when the forward region of the web 64 is restrained, the normal tendency of the material on the hump table 68 is to rise from the table and assume the dotted line curvature which represents the hump H. Suitable venting of the space between the web and hump is provided to avoid air pressure build up which controls in part the full and quick collapse of the hump H when desired. The rise of the hump H is sufliciently gradual that partial vacuum conditions are insignificant.

The punch press 42 is positioned forwardly of the hump table 68 and, in passing from the hump table to the press, the web 64 passes over a guide portion which appears at 80 in FIG. 5. A pair of solenoid-actuated clamps 82, one on each side of the guide table 80, are adapted, upon energization of their respective solenoids S1, to engage thelateral edge regions of the moving web 64 and clamp the same against the table 80 and thus arrest forward movement of the web at a predetermined period in the press cycle.

The clamp solenoids S1 are operable under the control of a relay magnet RM1 associated with a stop 84 in a manner that will be described presently, the stop being positioned forwardly of the clamps 82 and in the path of movement of the leading edge 86 of the web 64. At such time as the two clamps 64 become effective to clamp the web against the table 80 and prevent forward movement thereof, the material of the web in the vicinity of the hump table 68 begins to gather in the form of the humplike accumulation H shown in dotted lines in FIG. 5. This accumulation or hump increases in height and is fed by the continuously operating straightening rolls 41 until such time as the clamps 82 release their hold on the Web 64. The clamps 82 thus establish a web clamping station 87 along the path of travel of the web.

The relay magnet RM1 is operable under the control of a spring pressed plunger 88 associated with the stop 84 and which trips the magnet and energizes the same at such time as the leading edge 86 of the web 64 engages the plunger and depresses the same. The relay magnet RM1 also serves, when energized, to maintain the press 42 in operation without interruption, the press being operated continuously.

Still referring in FIGS. 4 and 5, the press 42 involves in its general organization the usual vertically reciprocable ram 90 which overlies the working area W of the press and operates upon descent thereof to drive shear dies 91 and 89 to sever a blank 30 from the portion of the web 64 which is projected into such working area and clean up corner dies 93 and 87. The ram 90 includes a die arrangement that is either in two spaced parts or has a cavity in the middle of it which accommodates

blank eject rollers

92 and 94 near its leading edge. A second relay magnet RM2 is adapted to become energized during the lip-stroke ofthe ram 90 and, when thus energized, it serves to actuate a solenoid S2 which controls the operation of the cooperating leading

eject rollers

92 and 94 by means of which the severed blanks are ejected from the working 'area W. The relay magnet RM2 is adapted to be actuated under the control of a spring biased finger 96 which is engaged by a cooperating bracket 98 mounted on the ram 90 and which is eifective on the upstroke of i the ram to trip the finger 96 and cause energization of the self holding relay magnet RM2. The leading

eject rollers

92 and 94 establish a blank ejecting station 99 along I the path of travel of the web 64, this station 99 being disposed within the confines of the working area W of the punch press 42.

Upon emerging from the trailing eject

rollers

100 and 102, the lead edge of the blank serves to trip a proximity switch SWP which effects deenergization of the relaymagnets RM1 and RM2 and consequent deenergization of the two solenoids S1 and S2, thus releasing the.

clamps 8 2 and disengaging the eject rollers, 92 and 94.

Refer-ring now to FIG. 4, a pair of longitudinally spaced standards 110 and 112 project upwardly from the V hump table 68.' The standard 110 carries at its upper end a photocell 114 while the standard 112 carries at its upper end a cooperating light source 116. As will be described presently,'the photocell and light source constitute no part of the cyclicly operable press instrumentalities but are provided as a precautionary or safety measure by means of which the motor M is deenergized and consequently the operation of the straightening apparatus 66' is terminated in the event that the press becomes jammed. Thus the feeding of coiled steel to the press 42 will be discontinued and with it the press mill shut down when the web is not reaching the working area.

A comparatively wide flexible strap 120 has its ends effectively secured to the standards 110 and 112 and is maintained under'tension by means of a spring 122. This strap overlies the hump table 68 and is adapted to become engaged by the'hump which is created in the web 64 during the building up of the web during each press cycle so that when the clamps 82 are released the hump, which at that time is at its maximum height, will by its own stress of flexure and by the pressure exerted upon itby the strap 120, be collapsed rapidly with the result that the feed end of the web and the excess material contained in the hump will be rapidly projected forwardly and into the working area W of the press to a point just short of the stops 84.

strumentalities will have been restored to their normal condition by reason of the tripping of the proximity complement of web material in the Working area W of the press 42 and actuate the stop SWl-tCh RMI. The high speed projection of accumulated web underthe influence of forcible collapse of the hump contributes largely to i the high speed of operation of which the present apparatus is capable and it constitutes oneof the principal features of the present invention.

*At this'time in the press cycle, the various control 'in- The schematic disclosure of FIGS. 4 and 5, in conjunction with the equally schematic disclosure of FIG. 1'

'41 and 33 backtothe source.

M2 sets the trailing eject

rollers

100 and 102, as'well'as the upper leading eject roller 94' into operation. Closure 8 the roller 102 with which it is iat all times in etfective contact. The upper leading eject roller 94 is also adapted to be continuously driven from the upper terminal roller 102, while the lower leading eject roller 92 is in the na i ture of an idler roller which is carried at oneend offa pivoted rocker arm 130,'the other end of the rocker arm being pivoted to a plunger 132 associated with thesolef 1 noid S2. When the solenoid S2 is deenergized, the idler roller 92 assumes a lowered 'po'sitionwherein it is out of effective contact with the continuously rotating eject roller 94 and below the path of travelof the web. Upon energiZat-ion of the solenoid S2, the plunger 132 is actuatedso that the roller 92 is raised into etfective cooperation with the roller 94 by reason of roller 92 engaging the blank 30 and raising it into contact with the roller 94. During such raising of'the blank 30'by the-roller t i 92, the leading edge of the blank is also'c'aused to' clear the stop 84 so that the

rollers

92 and 94 may advance the blank to the terminal eject rollers 100 and previously described at any speed desired.

The press ram is reciprocable in its vertical path of M3. A microswitch 146 is positioned in the vicinity of the ram 90 and is adapted to have its normally closed contacts opened momentarily at the time when the ram 90 reaches its uppermost position. The microswitch is disposed in the electric circuit for the motor M3 and serves a purpose that will be set forth presently when the control circuitry of the apparatus is described. The microswitch 146 is operable under the control of a finger 148 mounted on the ram 90.

Considering now the control circuitry by which the above described machine functions are accomplished in their proper sequential order, it should be noted that upon closure of the master switch MS, current isrmade available from the source S, which may be the conven tional'commercial power line, for all of the electrical instrumentalities associated with the apparatus. At such time as the switch MS is closed, the motor M1 will become.

energized, the circuit for this motor extending from the source S through leads 11, 13, 15 and 17, normally closed contacts of the relay magnet RM3, lead 19, motor source.

forwardly along .the hump table 68. Closure of the master switch MS also establishes a circuit through the 7 motor M2, this circuit extending from the source S, through leads 11, 35, 37 and 39, motor M2, and leads Energization of the motor of the master switch MS'also establishes a circuit through the motor M3, the circuit extending from the source through leads 11, 13, 15 and 43, normally closed contacts of the microswitch 146 (now closed by reason of the lowered position of the ram 90), leads 45 and 47, motor M3, and leads 49, 23, 25, 27, 29, 31 and 33 back to the source S. Energization of the motor M3 sets the press 42 into operation.

As soon as the leading edge of the web64 moves the plunger 88 associated with the stop 84, the plunger becomes depressed to provide a web stop limit and trips the relay magnet RM1, thus closing the #1, #2 and #3 contacts thereof. magnet RM1 establishes a holding circuit through the magnet, this circuit extending from the source S through leads 11, 35, 37, 51, 53 and 55, normally closed #1 contacts of the proximity switch SWP (now closed), lead 57, #1 holding contacts of the relay magnet RM1, lead 59, the magnet RM1, and leads 61, 29, 31 and 33 back to v the source.

Closure of the #1 contacts of the;

Closure of the #2 contacts of the relay magnet RM1 establishes a second circuit through the motor M3, such circuit extending from the source S, through leads 11, 13 and 63, #2 contacts of the magnet RM1, leads 65 and 47, motor M3, and leads 49, 23, 25, 27, 31 and 33 back to the source. This latter circuit maintains the motor M3 in operation at such time as the contacts of the microswitch are open. Since the contacts of the microswitch 148 are open only for a brief interval when the ram 90 is at the top of its stroke, these contacts normally maintain the motor M3 in operation during substantially the entire stroke of the ram 90. Closure of the #2 contacts of the relay magnet RM1 bridges the momentary opening of the contacts of the microswitch 148 and thus the press 42 is normally maintained in constant operation. The motor M3 will become deenergized to stop the press 42 only when both the contacts of the microswitch 148 and the #2 contacts of the relay magnet RM1 are open. This latter condition will take place only in the event that the web 64 becomes jammed or, if for any other reason, as for example a stock run-out, the leading edge of the web fails to engage the plunger 88 associated with the stop 84.

Closure of the #3 contacts of the relay magnet RM1 effects actuation of the clamps 82 by energizing the solenoids S1 associated therewith. The circuit for these solenoids S1 extends from the source, through leads 11, 35 and 71, #3 contacts of the relay magnet RM1, lead 73, solenoids S1, and leads 75, 25, 27, 29, 31 and 33 back to the source. Upon energization of the solenoids S1, the clamps 82 move into contact with the moving web 64 and hold the same against further forward movement so that the hump H on the hump table 68 begins to build up as previously described and the web material gathered thereby is held in compression by the strap 120 for projection into the working area W of the press for the next succeeding press cycle. While the hump H is thus being formed, the ram 90 descends and severs a blank 30 from the web 64 but with no efiect upon the magnet-actuating finger 96 by the trip finger 98 but, as the ram subsequently rises, the relay magnet RM2 is tripped in the manner previously described, thus closing the #1 and #2 contacts of this magnet. Closure of the #1 contacts of the relay magnet RM2 establishes a holding circuit through the magnet, the circuit extending from the source S through leads 11, 35, 37, 51, 53 and 77, #2 cont-acts of the proximity switch SWP, lead 79, #1 contacts of the relay magnet RM2, lead 81, the magnet RM2, and leads 83, 31 and 33 back to the source.

Energization of the #2 contacts of the relay magnet RM2 serves to cause energization of the solenoid S2 and consequent retraction of the plunger 132 thereof, thus causing the lower leading eject roller 92 to be raised into engagement with the blank 30 which has been severed from the web 64 by descent of the ram 90. The circuit for the solenoid S2 extends from the source S through leads 11, 35, 37, 51 and 85, #2 contacts of the relay magnet RM2, lead 87, the solenoid'SZ, and leads 89, 27, 29, 31 and 33 back to the source.

Movement of the lower leading roller 92 into contact with the blank 30 forces the latter into contact with the continuously operating upper roller 94 as the ram is moving upwardly and the blank is thus lifted above the level of the stop 84 so that the leading

eject rollers

92 and 94 will advance the blank to the trailing eject

rollers

100 and 102. These rollers are continuously operable and they serve to eject the blank 30 onto the conveyor 44.

In moving from the trailing eject

rollers

100 and 102, the blank 30 trips the proximity switch SWP, thus opening the #l and #2 contacts thereof. Opening of the #1 contacts serves to discontinue the previously described holding circuit for the relay magnet RM1, while opening of the #2 contacts serves to discontinue the previously decribed holding circuit for the relay magnet RM2. Both of these relay magnets thus open their associated contacts and, as a consequence, the circuits for the clamp solenoids S1 and the blank-ejecting solenoid S2 are opened. Additionally the #2 contacts of the relay magnet RM1 become opened but opening thereof has no effect on the motor M3 which drives the ram because the alternative motor circuit extending through the contacts of the microswitch 146 remain closed at this time. The press 42 therefore continues to operate without interruption. At this point, the apparatus is restored to the condition which it assumes at the commencement of the cycle and the plunger 88 of the stop 84 is readied for contact by the leading edge of the oncoming web 64 well before the ram starts another cycle. 9

At the risk of repetition it is pointed out that contact of the plunger 88 by the leading edge of the web 64 follows quite rapidly and takes place before the ram is cleared to start its next cycle. This is because release of the web 64 by the clamps 82 allows the spring loaded strap 120 to immediately and forcibly collapse the hump H and project an amount of web material equivalent to that gathered in the hump forcibly and with great linear speed into the working area W of the press. All but an inch or so is thus provided, leaving a slight amount of longitudinal feed of the web which instantly follows the straightening rolls 41 at their feed rate. The feed rate of the straightening rolls is gentle enough that no damage or bounce occurs at the feed limit stops. Thereafter this described operation of the apparatus is repetitive indefinitely.

As previously stated, the photocell 114 and its associated circuit normally have no direct function in connection with the press cycle. The circuit for the photocell is effective only in the event that the height of the hump H rises above a predetermined level by reason of a jamming of the web 64 at a point downstream from the hump. For example, failure of any of the electrical circuits associated with the press 42 resulting in failure of the terminal rollers and 102 to eject a blank will result in failure of the contacts of the proximity switch SWP to open, thus clogging the entry end of the working area W of the press. Any contingency which prevents release of the clamps 82 will also cause indefinite accumulation of material in the hump H and, at such time as the height of the hump causes the light beam emanating from the light source 116 to be interrupted by the web 120, the local circuit for the photocell 114 which has been designated in its entirety at 91 will energize the relay magnet RM3, thus opening the contacts thereof and discontinuing the previously described circuit through the motor M1. Deenergization of the motor circuit thus terminates the operation of the straightening device 66 and stops the forward feed of the web 64.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit of the invention. For example, wherein the illustrated embodiment of the invention the clamps 82 and the lower initial eject roller 92 have been illustrated and described as being electrically actuated, it is within the purview of the present invention to actuate these instrumentalities by fluid motors, either pneumatic or hydraulic. In such instances, the solenoids S1 and S2, instead of directly actuating these devices, may be operatively associated with solenoid valves which control the operation of associated fiuid pressure cylinders. Similarly, although not as desirable and fast, the ram 90* may be of the intermittently operable type instead of being continuously operable. In such an instance the contacts of the microswitch 146 may be omitted and the #2 contacts of the relay magnet RM1 will be employed in a suitable manner for effecting energization and deenergization of a solenoid-actuated clutch which selectively controls the operation of the ram. Therefore, only insofar as the 1 1 invention is particularly pointed out in the accompanyin claims is the same to be limited.

What is claimed is: i 'f 1. Ina shelf forming apparatus the combination of a punch press having a die arrangement defining a cavity within itswork area, a feed stop for locating the leading edge of feed stock properly in the work area, means for feeding stock against said feed stop, a feed stock clamp ahead of said work area arresting feed movement of ,the feed stock, said feed stop including a movable element displaced by the leading edge of the feed stock for activating said clamps, a work piece ejecting means disposed in said cavity including a continuous running wheel whose 7 working location is above the level of a severed work piece during the back stroke of the dies and an idler wheel disposed in its retracted portion below the level of the work pieceand movable towards and against the running wheel within the work area, means actuated upon the back stroke for the dies for moving said idler wheel from its retracted position into pressure contact with a work piece and with said running wheel for raising the leading edge of'the work piece clear of said feed stop and releasing said 'movable element, a pair of ejection rollers beyond said' feed stop engaging and rapidly ejecting the V edge of feed stock properly in the work area, a work piece ejecting means disposed in said cavity including a continuous running wheel whose location is above the .level of a severed work piece during the back stroke of V the dies and an idler wheel disposed in its retracted portion below the level of the work piece and movable towards the running wheel to lift the work piece against the running wheel and drive it from the work area, means actuated upon the back stroke of the dies for moving said idler wheel from its retracted position into pressure contact with a work piece and with said running wheel for raising the leading edge of the work piece clear of said feed stop, means actuated upon clearance of the'work area by the work piece for returning said idler wheel to its starting position, means for feeding stock towards said feed stop at a constant rate, clamp means for arresting forward movement of'the feed stockadjacent to the en trance to said. work area whensaid stop is reached by the leading edge of said feed stock, means for accumulat- 1 ing stock continuing to be fed after actuation of said clamp-means in a hump under fiexure stress, means for. 'releasing said. clamping means during clearance of said 7 working area by the work piece, and means for propelling said accumulated stock at an accelerated rate into the work area with'the leadingedge just short of said feed stop upon release of said clamp means with the remaining distance to the feed stop at said constant rate.

3. In a shelf forming apparatus of the character de scribed, in combination, a punch press including a vertically reciprocable ram havingv a severing die adapted upon reciprocation of the ram to repeatedly sever flat blanks from a continuous web of sheet metal, means establishing a working area for said press and into which the leading portion of the web is adapted to be recurrently projected for severance therefrom of the blanks, means providing a linear path of movement for said Web, said path terminating within said working area, means establishing a web feeding station, a web gathering and accumulating station ahead of said working area, a web clamping station and a blank ejecting station along said path in the direction of travel of the web and in the order named, means at said web feeding station for impelling said web continuously along said path, means at said clamping V 12 a station and engageable with said web for, releasably clamping the web and terminating the forward movement thereof, means at said gathering and accumulating sta- 7 tion constraining the adjacent portion of the web to move vertically out of said path in the form of a bump during. such time as said clamping m'eansis effiective, releasable means at said ejecting station for impelling the severed V blanks and ejecting them from the working area, means operable by the leading edge of the web which has fully traversed said'working area for rendering said clamping means effective whereby, upon descent of the ranna blank' 1' will be severed from the web in the working area, means operable during upward movement of the ram and'after the blank has been severed from thejweb for rendering said blank impellingmean's efiiective, andmeans operable. during projectionlof theblankfrom said working area for rendering said web clamping means and blank in1-" fpelling means ineffective; j V

'4. In a shelf forming apparatus, the combination set forth in claim 3, wherein the means for constraining the adjacent portion of the web to move vertically out of said path in the formof a hump comprises an upwardly and forwardlyinclined ramp surface underlying the web a at said web gathering and accumulating station ahead of Y said clamping station. a

5. In a shelf forming apparatus, the combination set forth in claim 3 and including, additionally, means at forth in claim' 3 and including, additionally, means at said i leading portion of the web into said working'area almost.

said web gathering and accumulating station for yieldin gly V maintaining the hump established at said web gathering;

and accumulating station under compression whereby,

upon release of said clamping means, the hump will be forcibly'collapsed and the. material accumulated therein forcibly propelled forwardly along said path to thus rapidly project said leading portion of the web into said working area almost to said operable means. 7 6. In a shelf forming apparatus, the combination set web gathering and accumulatingstation yieldingly exerting a downward pressure on the crest portionof the hump.

established at said latter station whereby, upon release of said clamping means, the hump will be forcibly collapsed;

and the material accumulated therein forcibly propelled forwardly along said path to'thusrapid1y project said to said operable means. I j I a 7. In a shelf forming apparatus, the" combination set forth in claim 3 and including, additionally, a vflexible strap disposed at said web gatheringand accumulating station, having its opposite ends secured to fixed reaction points, and positioned to have its medial region yieldingly bear against the crest portion of the hump established at r said latter station whereby, upon releaseof said clamping I means, the hump will be forcibly collap'sedand the mate-., rial accumulated therein forcibly distributed forwardly] along said path to thus rapidly project said'leadingportion of the web into said working area'almo'st to said operable means.

8. In a shelf formm g apparatus, the combination set forth in claim 3, wherein the rate of reciprocation of said ram and the rate of lineartravel of the web forwardly along said path under the influence of said web impelling means are such that the amount of Web material gathered in said hump during the time that the clamping means is effective is such that upon collapse ofthehump the leading portion of the web will be projected across the'major portion of said working area, said web. impelling means being effective to complete the projection of said leading portion of the web fully across said Working area and' against said operable means.

9. In a shelf forming apparatus of the character de- 7 upon reciprocation of the ram to repeatedly sever an blanks from a continuous web of sheet metal, means establishing a working area for said press and into which the leading portion of the web is adapted to be recurrently projected for severance therefrom of the blanks, means providing a linear path of movement for said web, said path terminating within said Working area, means for recurrently feeding the leading portionof the web into said working area, a feed stop defining the front of said working area and projecting above the level of said path and including a control element, engageable by the leading edge of the web for locating the leading edge of the web with respect to said working area and actuating reciprocation of said ram, a rotatable blank-ejecting roller disposed within said working area and positioned above the level of said stop, means for continuously rotating said eject roller, a cooperating idler roller disposed within said working area, said idler roller being movable from a retracted'position wherein it is disposed below the level of said path and out of engagement with said eject roller to an advanced position wherein it engages a severed blank and raises the same above the level of said stop and into engagement with said eject roller for :tractionally impelling the blank forwardly over said stop and control element to project the blank form from said working area, and means controlled by said control element for reciprocating said ram in timed relation to the projection of the leading portion of the web into said working area, means normally maintaining said idler roller in its ret'racted position, means operable under the control of said ram on its retracting movement for moving said idler roller to its advanced position, and means operated by said blank during projection of the blank from said working area for disabling said last mentioned roller moving means.

10. In a shelf forming apparatus of the character described, in combination, a punch press including a vertically reciprocable ram having a severing die adapted upon reciprocation of the ram to repeatedly sever flat blanks from a continuous web of sheet metal, means establishing a working area for said press and into which the leading portion of the web is adapted to be recurrently projected for severance therefrom of the blanks, means providing a linear path of movement for said web, said path terminating Within said working area, means estab lishing a web feeding station, a web gathering and accumulating station, a web clamping station ahead of said working area and a blank ejecting station along said path in the direction of travel of the web and in the order named, means at said web feeding station for impelling said web continuously along said path, means at said clamping station and engageable with said web for releasably clamping the web and terminating the forward movement thereof, means at said gathering and accumulating station constraining the adjacent portion of the web to move vertically out of said path in the form of a hump during such time as said clamping means is effective, releasable means at said ejecting station for impelling the severed blanks and ejecting them from the working area, a stop including a control member positioned at the termination of said path and engageably by the leading edge of the web when the web has been projected completely across said working area, relay actuated means operable by said control member when said stop is engaged by said leading edge of the web for rendering said clamping means effective and activating reciprocation of the ram to sever, a blank from the web in the working area, relay actuated means operable during upward movement of the ram and after the blank has been severed from the web for rendering said blank impelling means effective, and means operable during projection of the blank from said Working area for rendering said web clamping means ineffective whereby the material of the web gathered at said gathering and accumulating station Will be forcibly distributed forwardly along said path to thus rapidly project the leading edge of the web about into engagement with said stop.

.11. In a shelf forming apparatus of the character described, in combination, a punch press including a vertically reciprocable ram having a severing die adapted upon reciprocation of the ram to repeatedly sever fiat blanks from a continuous web of sheet metal, means establishing a working area for said press and into which the leading portion of the web is adapted to be recurrently projected for severance therefrom of the blanks, means providing a linear path of movement for said web, said path terminating within said working area, means establishing a web feeding station, a web gathering and accumulating station, a web clamping station and a blank ejection station along said path in the direction of travel of the web and in the order named, means at said web feeding station for impelling said web continuously along said path, a normally ineffective clamping device at said clamping station for engaging the web and terminating the forward movement thereof, a clamp solenoid operable upon energization thereof to render said clamping device eifective, means at said gathering and accumulating station constraining the adjacent portion of the web to move vertically out of said path in the form of a hump during such time as said clamping device is effective, a normally ineffective blank impelling device at said ejection station for impelling the severed blanks and ejecting them from the working area, an eject solenoid operable upon energization thereof to render said blank impelling device effective, an electric circuit for each solenoid, a first relay magnet having a pair of normally open relay contacts disposed in the circuit for the clamp solenoid and a pair of normally open holding contacts, an electric circuit for each solenoid, a second relay magnet having a pair of normally open relay contacts disposed in the circuit for said eject solenoid and a pair of normally open holding contacts, a combined limit stop and plunger positioned in said path and engageable by the leading edge of the web and effective when engaged thereby to close the contacts of the first relay magnet, a trip finger positioned in the path of movement of the ram and effectively engageable thereby during upward movement of the ram to close the contacts of the second relay magnet, and a proximity switch having a pair of normally closed contacts disposed in the circuit for the first relay magnet and a pair of normally closed contacts disposed in the circuit for the second relay magnet, said proximity switch being provided with a trip finger disposed in the path of the blanks projected from the working area by said blank impelling device.

'12. In a shelf forming apparatus, the combination set forth in claim 11 and including, additionally, means at said web gathering and accumulating stat-ion for yieldingly maintaining the hump established at said web gathering and accumulating station under compression whereby, upon release of said clamping means, the hump will be forcibly collapsed and the material accumulated therein forcibly propelled forwardly along said path to thus rapidly project said leading portion of the web into said working area.

13. In a shelf forming apparatus, the combination set forth in claim 11 and including, additionally, means at said web gathering and accumulating station yieldingly exerting a downward pressure on the crest portion of the hump established at said latter station whereby, upon release of said clamping means, the hump will be forcibly collapsed and the material accumulated therein forcibly propelled forwardly along said path to thus rapidly project said leading portion of the web into said working area.

14. In a device of the class described the combination of a punch press having shear dies for severing blanks from coiled sheet metal feed stock, means for feeding stock to said dies at a continuously constant controlled rate, a feed stop means spaced from said shear dies engaged by the leading edge of said feed stock to locate the leading edge properly in working position, a movable located ahead of said dies and activated by said control member, means for accumulating in a hump under flexure :stress feed stock fed towards said dies during the activation of said clamp means, means between said shear dies and said stop means controlled by retraction of the dies for propelling said blank up and over said feed stop means,ejection means beyond said stop means receiving and ejecting the blank from the punch press, control means beyond said ejection means activated by the leading edge of the ejected blank for de-activating said clamp means and said propelling means, said accumulated feedstock 1 control member engaged by said feed stock in said Work- 4 upon de-activation of said clamp means.

ReferencesCited by the Examiner V UNITED STATES PATENTS 1,499,537 7/1924 Kurkowski 83-221 7 2,025,418 12/1935 Moore 83 156' 2,436,192 2/1948 'Braun 83156 2,480,781 8/1949 Simpson 83-236- FOREIGN PATENTS 594,060 3/1960 Canada.

WILLIAM W. DYE-R; 111., Primar Examiner.

Assistant Examiners.

Claims

1. IN A SHELF FORMING APPARATUS THE COMBINATION OF A PUNCH PRESS HAVING A DIE ARRANGEMENT DEFINING A CAVITY WITHIN ITS WORK AREA, A FEED STOP FOR LOCATING THE LEADING EDGE OF FEED STOCK PROPERLY IN THE WORK AREA, MEANS FOR FEEDING STOCK AGAINST SAID FEED STOP, A FEED STOCK CLAMP AHEAD OF SAID WORK AREA ARRESTING FEED MOVEMENT OF THE FEED STOCK, SAID FEED STOP INCLUDING A MOVABLE ELEMENT DISPLACED BY THE LEADING EDGE OF THE FEED STOCK FOR ACTIVATING SAID CLAMPS, A WORK PIECE EJECTING MEANS DISPOSED IN SAID CAVITY INCLUDING A CONTINUOUS RUNNING WHEEL WHOSE WORKING LOCATION IS ABOVE THE LEVEL OF A SEVERED WORK PIECE DURING THE BACK STROKE OF THE DIES AND AN IDLER WHEEL DISPOSED IN ITS RETRACTED PORTION BELOW THE LEVEL OF THE WORK PIECE AND MOVABLE TOWARDS AND AGAINST THE RUNNING WHEEL WITHIN THE WORK AREA, MEANS ACTUATED UPON THE BACK STROKE FOR THE DIES FOR MOVING SAID IDLER WHEEL FROM ITS RETRACTED POSITION INTO PRESSURE CONTACT WITH A WORK PIECE AND WITH SAID RUNNING WHEEL FOR RAISING THE LEADING