US1947015A

US1947015A - Strip stock feed for presses

Info

Publication number: US1947015A
Application number: US273500A
Authority: US
Inventors: Frederick J Littell
Original assignee: Littell Machine Co F J
Current assignee: FJ Littell Machine Co
Priority date: 1928-04-28
Filing date: 1928-04-28
Publication date: 1934-02-13
Anticipated expiration: 1951-02-13

Description

Feb. 13, 1934. F; J. LITTELL 1,947,015

' STRIP STOCK FEED 150R PRESSES Filed'April 28. 1928 6 Sheets-Sheet l F. J. LITTELL STRIP STOCK FEED FOR PRESSES 6' Sheets-Sheet 2 Filed April 28. 1928 jade/72%?! z realerooi J Feb. 13, 1934. I |TTE| L 7 1,947,015

STRIP STOCK FEED FOR PRESSEs Filed April 28, 1928 6 Sheets-Sheet 3 M 'i a 2%30 I L j I 25 J Tm-J --JO 12 552665: z ex v read 6716012 I Feb. 13, 1934. FLJ; 1,947,015

STRIP STOCK FEED FOR PRESSE'S Filed April 28, 1928 G SheetS-Sheet 4 Feb. 13, 1934.- J E L, I 1,947,015

STRIP STOCK FEED FOR PRESSES Filed April 28, 1928 6 Sheets-Sheet 5 Feb. 13,11,341 F U TELL, 1,947,015

STRIP STOCK FEED FOR PRESSES Filed April 28, 1928 6 Sheets-Sheet 6 against displacement horizontally so that the Patented Feb. 13, 1934 STRIP STOCK FEED FOR PRESSES Frederick J. Littell, Chicago, 111., assignor to F. J. Littell Machine 00., Chicago, 111., a corporation of Illinois I Application April 28, 1928. Serial No. 273,500 10 Claims. (01. 271-2.4)'

This invention relates to attachments for metal working machines, such as punch presses, whereby stock material in the form of strip metal can be conditioned and fed to theworking tool of the machine where it is subjected to blanking and other steps incident to forming articles from the material, and the scrap'or remanent portions of the material, by continuation of the feeding operation and by subjection to a suitable scrap cutter, can then be discharged from the machine in physical form that renders it convenient for handling as waste. The several operative units which go to make up the conditioning and feeding mechanism of such an attachment are usually mounted in longitudinal alignment upon an elongated press bed and actuated from the plunger or shaft of the machine which they serve, and they have heretofore been equipped with certain adjunctive devices whereby they may be thrown open for convenient introduction of the stock, or manually manipulated for initiating the feed and adjusting the approach of the stock to the working tool, or thrown into and out of action at will; also to have their operation controlled to render it intermittent until such time as the Work is found by observation to be progressing satisfactorily, and then changed to continuous operation, all at the will of the operator.

The object of the present invention is to improve the construction and operation of the several units of conditioning and feeding mechanism of the kind alluded to, with respect to both their individual functions and their relations one to another; and, to these ends, the invention proceeds upon the principle of providing, at the intake end of the machine where the stock is received in strip form preferably from acoil or reel, a novel stock guiding and oiling unit, a stock straightening unit, and an intake feeding unit; and on the discharge side of the machine, a discharge feed unit coupled to operate in unison with the intake feed unit, a driving unit for both feed units, and, if desired,,a scrap cutter; which said units, function generally in the manner hereinbefore set forth but specifically in the improved manner hereinafter described, whereby they attain the object herein stated. That is to say The guiding and oiling unit comprises vertical rollers which impinge only against the edges of the stock, and lubricating rollers suitably supplied with oil, which impingeagainst and simultaneously oil the upper and lower faces of the stock; the lubricating rollers confining the material against displacement vertically and their closely related guiding rollers confining it guiding and oiling unit as a whole accurately positions and properly presents the stock to the next unit, which comprises stock straightening means which is to deflect the stock in the direction of its minor transverse dimension sufliciently beyond its limit of elasticity to give it a permanent set in straight form and thereby remove the curvature incident to coiling the stock upon the reel. This straightening unit comprises upper and lower series of rolls. the rolls of the two series alternating inposition so that the rolls of the upper series are vertically over spaces between the rolls of the lower series, and means for adjustably depressing the individual rolls of the upper. series so that they intersect or dip below the feed line which is tangential to the upper surfaces of the rolls of the lower series, the degree of such intersection being regulated at will to determine the deflection of the stock in giving it the desired permanent set in straightened form; also means for adjusting these upper rolls collectively in the form of a quick opening means for elevating'them and holding them elevated as a group to facilitate convenient passage of the stock at the time of first introducing it; said quick opening or group elevating means returning the upper series to operative position without disarranging their individual adjustments, and thereby insuring delivery of stock to the next unit, which is the intake stock feeding .unit, in an accurately straightened and fully lubricated condition and permitting succeeding coils of the same gauge stock to be successively introduced in the same condition without requiring readjustment. The intake stock feeding unit comprises a pair of rolls with one-way clutch drive, having means for adjusting their feeding grip upon the stock as well as means for quickly opening them and holding them open for introduction of the forward end of the stock in initiating the operation; a manual drive for the said rolls in addition to the automatic drive from the machine operating through the medium of its own one-way clutch so that the manual drive is wholly independent of the automatic drive-and remains stationary when the automatic drive is functioning; also a quick opening mechanism including an arm which is normally in the path of a part that reciprocates with the plunger of the machine and causes the feed rolls to open andrelease the stock to the justifying effect of the operating dies at each stroke of, the latter; also a novel construction of detent which holds the advance feed rolls open and thereby interrupts the feed when desired, for instance, when fresh stock is being introduced and it is desired to manipulate the manual drive of the feed and completely discharge spent stock from the machine; such detent being automatically released by the working plunger of the machine when operations are to be resumed. The discharge feed unit comprises a pair of rolls in all respects similar to those of the intake feed. unit and having (lit the same quick opening and automatic macle opening attachment but without the. automati cally released detent for holding them open. The driving unit for the two-feed units com prises a horizontal drive shaft common to both and having continuous rotary diagonal-gear driving connection with each, as distinguished from oscillating driving connection; a thrust bar extending from the operating shaft of the ma= chine to which it is connected through' means of a novel form of radial screw adjustment to vary the stroke of the rod, a rack and pinion connection between the thrust rod and the hori= zontaldrive shaft, and the pinion of which said connection has a one-way driving clutch connec tion with said shaft, and diagonal gears of the said drive shaft meshing with diagonal gears on the shafts of the lower rolls of the respective feed units which. in turn are positively geared to the respective upper rolls. The scrap cutter, when employed, comprises a guillotine type of cutter intersecting the path of the spent stock and carried by the intermediate portion of an actuating lever, the outer end of which is ful= crumed upon a bracket upstanding from the table, while the inner end is received by a pin on the press plunger and is actuated to maintain cutting strokes of the cutter as the operation proceeds; both the fulcrum point and the plunger actuated connection being adjustable in the direc= tion of scrap-feed to permit the point of severance to be located through the portion of the scrap which offers least resistance to the cutting stroke. In the accompanying drawings, in which the preferred embodiment of the invention is shown by way of illustration- I Figure 1 is a front elevation of an automatic punch press having the several features of the invention applied thereto.

Figure 2 is an elevation of the same, as seen from the right-hand end of Figure 1.

Figure 3 is a plan view of the table and the press attachments mounted thereon, the pop-- tions of the press proper being omitted.

Figure 4 is a detail view showing, in axial section, the manual drive for the feeding units.

Figure 5 is a transverse section on the line ore-5a: of Figure 4, showing the clutch through which rotation of the drive shaft by the hand wheel is established inone direction.

Figure 6 isa detail view of one of the two substantially identical feeding units, the section being taken in the vertical plane of the axes of the rolls.

Figure 7 is a section through the straightening unit, in a vertical plane, which coincides with the axis of one of the upper rolls and of the quick opening cam shaft.

Figure 8 is a detail view of the automatic driv= ing unit for the feed units.

Figure 9 is a detail view of the timing connection of the crank disk and main shaft of the machine through means of which the feed units are properly timed with respect to the working strokes of the machine.

Figures 10 and 11 are, respectively, a transverse section and an axial section which establishes the one-way driving connection between the pinion of the automatic driving unit and the shaft which serves in common for the two feeding units.

Figure 12 is a detail view of the detent em-,

ployed on the intake side of the press, for holding down the quick opening arm of the intake feed units.

es 13 and it are detail views, in vertical neonate section and top section on line less-1dr, respectively, of a modified construction of detent for the quick opening arm f the intake feed unit.

Figures and 16 are, respectively a side elevation and a front elevation of the preferred construction of automatic quick opening and closing feed unit with releasable hold-open means; and

Figure 17 is a detail view, in position as seen in Figure 15, of the connections through which the press-plunger opens the feed-rolls to free the stock in the feed unit of Figures 15 and 16, and Figure 18 a modification thereof.

Referring more particularly to Figures 1, 2, and 3, 1 represents the working tool or plunger of a press, 2 the bed which carries the die that receives the punch, 3 the main crank shaft of the machine which actuates the plunger, 4 the driving wheel for said shaft, 5 the automatically arrested driving clutch between said wheel and said crank shaft, 6 the control for the clutch 5, and 'l the connecting rod and 8 the pedal for said control. The parts as thus far enumerated may be of any appropriate known construction.

9 represents the guiding andoiling unit, 10 the straightening unit, 11 the intake feeding unit, 12 the discharge feeding unit, 13 the automatic driv ing unit, 14 the manual driving unit, and 15 the scrap cutter, all of which are mounted upon the bed 16 designed for application to a press of substantially the kind described, and adapted to serve said press in the manner hereinbefore indicated.

As shown at the right-hand end of Figures 1 and 3, the guiding and oiling unit 9 comprises a pair of vertical. guide rollers 17 supported with lateral adjustment upon the frame 18 of said unit, and oiling rollers 19, 20 also mounted in said frame, with suitable relative adjustment, such as typified by the set screws 21 to adjust said oiling rollers to stock of different thicknesses, an oiling trough 22 having bottom perforations 23 that adapt the trough to drip oil upon roller 20 from which it is transferred toroller 10, and an oil reservoir 24 mounted upon the bracket arm 25 and having a discharge cook 26 which adapts it to feed measured quantities of oil to the trough 22'.

The effect of guiding and oiling unit upon flat metal stock fed into the machine and still retaining the curvature of the roll is to guide the strip of stock horizontally but with vertical play by means of the vertical rolls 1'], and vertically but with freedom of vertical rocking movement by means of the superposed horizontal rollers 19, 20, thereby avoiding wear and tear upon the vulnerable oiling rolls which are usually faced with absorbent material, and without losing constant contact of the rolls with both sides of the stock, and thereby presenting the stock at a proper level and in the longitudinal axis of the machine, as

well as in thoroughly lubricated condition on both of the faces, to the straightening unit.

The straightening unit 10 comprises a lower series of rolls 27, three of which are shown, but

which may be either two, three, or five according to the degree of straightening treatment required by the stock, which generally varies according to the thickness of the stock, and a series of upper rolls 28, generally one less in number than the lower rolls and positioned vertically them to dip below or intersect the feed line, which is tangential to the upper surfaces of the rolls 27, and thereby deflect the flat stock suificiently beyond its elastic limit and in the direction opposite to the curvature which the stock takes on in coiling, to eliminate the curvature and give the stock a permanent set in a straight line and therefore in proper condition for presentation to the punch. Frame 30, which carries upper rollers 28 and adjusting screws 29 of the straightening unit, is adapted to be lifted bodily with all the elements which it carries through means of a cam shaft 31 controlled by a lever 32 so that the A advance end of the stock may be passed through the straightening unit in originally setting up the machine, and when it is desired to have the straightening unit operate, the upper rolls may be returned to operative position by a reverse movement of the cam shaft 31 and without having lost the accurate adjustment of the rolls appropriate to the particular stock being operated upon.

The intake feed unit 11, as shown more clearly in Figure. 6, comprises a lower roll 33 mounted upon a shaft 34 to which it is keyed by any suitable instrumentality, such, for instance, as a- Woodrufi key 35; an upper roll 36 mounted upon shaft 37 to which it is similarly keyed at 38;

gear wheels

39, 40 through means of which

shafts

34 and 37 are connected to compel them to rotate in unison;

springs

41, 42 acting downwardly upon the

bearing blocks

43, 44 of the upper roll and pressing said roll into stock feeding relation to the lower roll 33; a quick opening twin lever 45 having inturned arms 45' fulcrumed at 46 and engaging beneath

bearing blocks

43, 44, as shown at 47 in Figures 1 and 6; a manual control for said quick opening arm consisting of cam 48 on shaft 49, controlled by hand lever 50 (Fig. 6) and through means of which said feed rolls may be opened in passing theforward end of the stock between them in starting the stock through the machine; automatic feed opening means 51 consisting of a set screw carried by a bracket 52 on the plunger 1 and presented by said bracket in position-to engage the end 53 of twin lever 45 each time the plunger 1 descends, thereby opening the feed rolls and freeing the stock so that it may respond to and have its position justified by the pilot pin 1a. on the end of the die beneath the plunger 1; and a detent for said quick opening arm (Fig. 12) to be used when first starting the stock through the feed unit 11, said detent comprising an arm 55 pivoted at 56 upon a stationary portion of the press, and having an adjustable screw 54 in its free end in position to stand over the arm 45 when the latter is depressed, thereby holding down said arm and keeping the feed rolls open until the forward end of the stock has passed through. Detent 54 is held normally out of arm engaging position by means of a spring 58, with the result that whereas thedetent 54 may be manually adjusted to overlie the arm 45 when the latter is depressed I and will remain in depressing engagement with said arm, the first descent of the plunger after such detention will slightly depress the arm and release the detent 54 from its frictional engagement with the arm, so that the detent may return under the action of its spring 58 and thereby restore the feed roll opening function to periodic automatic functioning, as already described.

The modified form of detent for the quick opening arm of the feed unit, as shown in Figures 13 and 14, comprises a latch. pivoted at 56a at its .machines of different sizes.

ing stroke of the press.

lower end, carrying an adjustable latching screw 54a at its upper end adapted by the pivotal action of the latch to engage over the quick opening arm 45 of the feed unit; the body of the latch comprising two

members

55a and 55a lapped one upon the other and held together by screws 59 with adjustment that adapts the latch to serve on stantially the same functionally as the detent shown in Figure 12, in that" when the arm 45 is depressed and this detent is manipulated to bring its latching screw 54a over the arm 45, it will be held in frictional engagement ,with the arm and prevent the arm from returning to roll closing position; but on the first descent of the pressplunger after such detention is set, the arm 45 will be depressed sufliciently to release the frictional engagement and the detent can then be thrown away from the arm 45 by means of its spring 58a, so that the automatic periodic opening of the feed unit, in resonance with the strokes of the press, will be resumed.

A modified construction of the feed unit on the intake side of the machine, and particularly the portions thereof which have to do with the manual and automatic opening connections as well as the hold-open means, and a construction that is believed to best serve .the purposes, is shown in Figures 15, 16 17, and 18. In these figures, all those parts which correspond in construction with parts shown in Figures 1, 2, and 6, bear reference characters identical with those in the last-named figures, and those parts which involve changes in construction but correspond in function, have similar reference characters qualified by the exponent b. Thus, in Figures 15, 16, 17 and 18, 33 and 36 represent lower and upper rolls mounted, respectively, upon

shafts

34 and 37, of which the shaft 37 is mounted in vertically sliding journal blocks 47 normally depressed by

springs

41 and 42; and these blocks 47 are adapted to be raised to open the rolls through means of a twin lever 45b having inturned arms 45b fulcrumed at 461) and engaging the blocks 47 at 47b. To actuate the twin lever 45b and thereby raise the blocks 47, shaft 40 carrying cam 48b, which acts upon the twin lever 45b as shown in Figure 16, also has mounted upon it cam 53b, best shown in Figure 15, where coacts with antifriction roller 45c mounted on the twin lever 45b to rock the latter upon its fulcrum 46b; and this cam 53b has a controlling arm 53c pivotally connected through slot andpin connection 570 (Figs. 15, 16 and 17) or link 57d (Fig. 18) with screw 57b in the arm 52, which as shown in Figure 1 projects from the vertically reciprocating plunger 1. Cam 53b has an abraupt shoulder 53d through which it impinges against the anti-fric-. tion roller 450 on twin lever 45b which causes a very quick opening of the

rolls

33, 36 and an equally quickor sharply localized release of the upper roll 36 to closing movement and return movement of cam 53b. Extending from this shoulder 53d, concentrically with the center of oscillation of cam 53b, is a surface 53a which holds the rolls open during the latter portion of the downward movement of the plunger 1 and the first portion of its return movement, so that after an adequate feed 'of the strip stock has taken place, and a fresh portion of the latter has been brought within reach of the forming die 1a, feed will be interrupted until completion of the work- Again, since screw 57b is vertically adjustable in thearm 52, and shoulder 53d constitutes the timing element of the This detent is sub-.

cam 53b, in determining when the feed is interrupted by the opening of the rolls on the downward stroke of the press and how soon the rolls will be released to resume feed on the upward stroke, this cam with its positive drive in opposite directions becomes an exceedingly accurate means of gauging the length of the feed of the stock and will insure accurate registry of the working die or punch with the impression of the pilot punch commonly used in work of the kind for which the machine is intended.

A modified construction of hold-open means, and one which is believed to give the best results, is likewise shown in Figures 15, and 16, and this consists of a finger piece 54b having a finger 54c movable from the full line to the dotted line position of Figure 15 to bring it from a normal position of lever release to a position of lever detention with respect to the twin'lever 45?); a stop finger 450. which arrests the movement of the finger piece in releasing position; a coiled spring 54} which yieldingly holds the finger piece in position of release; and a manipulating finger 549 by which the finger piece can .be manually set in the dotted line position of Figure 15. As in the previous forms of hold-open devices herein described, the finger piece 54b will be held in detaining position over the depressed twin lever 45b by its interengagement with the latter under the pressure induced by the roll

depressing springs

41, 42, until a downward movement of the arm 52 on the press plunger causes the twin lever to be depressed sufficiently to release the finger piece to the action of its return spring 54f. Thus, the automatic roll opening function of Figures 15, 16, 1'7 and 18, and the technique of manipulation of the voluntary hold-open device shown therein are substantially the same as described With reference to Figures 1, 2, 6, 12 and 13.

It is to be understood that shaft 40 with the cam 48 fixed thereon, and manually operated lever 50 for voluntarily opening the rolls in starting the strip stock by hand at the beginning of the operation, are rotatable independently of the automatically actuated opening cam 53b, the latter being sleeved upon shaft 40. Likewise the manually set hold-open device or finger piece 54b does not partake of the rotation of either the cam 53b'or the shaft 40.

The discharge feed unit 12 is in all respects similar to the intake feed 11 except that no detent such as described with reference to Figure 12 or Figure 13 is required, it being merely necessary to throw the arm 50a of the cam 48a to depress the roll opening arm 45a in starting the scrap through the discharge rolls, and to provide a replica of the automatic opening elements in the presence of the adjusting screw 51a in the bracket 52a to insure automatic periodic opening of the discharge rolls and to construct the rolls themselves substantially as described with reference to the intake feed unit 11, as detailed in Figure 6.

The driving unit 13, serving incommon for the intake feed unit 11 and the discharge feed'unit 12, comprises a horizontal shaft 60 extending longitudinally of the machine and through gear boxes 61 and 61a of the respective driving units where the said shaft is connected in the respective boxes with the lower shafts 34 and 34a of the respective feed units through means of diagonal gearing, such as shown at 62 in connection with the intake drive shaft 34 (Fig. 6), so that the said lower shafts of the driving elements are positively driven in synchronism with the shaft 60, and identical driving effect is developed in both. feed mergers units; also a rack 63, shown in detail in FigureB, meshing with pinion 64 on said driving shaft 60, although not directly connected with the shaft, and a one-way clutch 65, shown in detail in Figures 10 and 11, which is so constructed, for instance, by providing it with cylindrical gripping rollers 66 and non-centered gripping faces 67 between which and a cylindrical surface 68 of the driven member of the clutch said rolls are pressed by means of springs 69, that all'motion transmitted by the rack 63 in the driving direction will be imparted to the shaft 60, and all back-lash of parts will be eliminated; a bearing box 70 provided with extension guards 71, 72 in which the rack 63 reciprocates; a thrust rod 73 forming an extension of the rack 63 and by which the rack is driven; a crank pin '74 with which thrust rod 73 is connected by means of the wrist bearing 75 and which said crank pin is mounted upon the disk '76 of the main crank shaft 3, as-shown in Figure l, and is radially adjustable thereon by means of the screw 77 threaded in the sliding pin block 78; also a circumferentially adjustable timing coupler '79, shown in detail in Figure 9, and comprising disk 80, keyed at 81 to the shaft 3 and connected with the crank disk 76 through means of bolts 82 fixed in one of the members, preferably the disk 76, and working through circumferential slots 82a in the other member, so that by loosing said bolts 82 and circumferentially adjusting the disk 76 relatively to the coupling disk 86 within the limits permitted by the slots 82a, the stroke of the rack 63, and consequently of the shaft 60 and of the feed units, can be properly coordinated with the strokes imparted by shaft 3 to the plunger 1.

The hand drive 14 for the feed drive shaft 60, as shown in detail in Figures 4 and 5, is connected with the shaft 60 through means of the clutch 83 for the purpose of rendering the hand drive 14 stationary while the

automatic drive

63, 64 is in function.

The effect of the automatic and manual drives coordinated as described, is to permit the press to be arrested in its operation, and the stock to be fed up to the exact relation desired to insure proper operation of the punch press, the shaft 60 being permitted by the clutch 65 of the automatic drive to respond to rotation imparted through hand drive 14 while the automatic drive is at rest; and with the detent 55 or its equivalent for the opening arm 45 of the intake feed unit, and through means of which the latter can be thrown out of driving effect upon the stock, it is possible to manipulate the discharge feed unit 12 to run the remnant of spent stock out of the machine when desired. In the automatic drive, the transmission of motion is positive and instantaneous, the advancement of the stock is exceedingly accurate, the working parts are all enclosed where they canbe immersed in oil, and the construction is greatly simplified over feed units used for similar purposes in automatic feed presses as heretofore constructed.

Scrap cutter 15 may consist of the vertically reciprocating guillotine cutting blade 84 mounted through means of the hanger 85 upon the lever 86 which has its outer end fulcrumed at 8'? through meansof link 88 upon the bracket 89, and its inner end in driven connection with plunger 1 through means of pin 90 and slot 91. In accordance with the practice established prior to the present invention, the scrap cutter 15 will be adjustable in the direction of feed to bring the plane of severance in the weaker portion of the scrap, and thus reduce the work of scrap cutting.

Iclaim:

i. In a machine for feeding punch presses, a feeding unit adapted to draw stock into the machine and present it to the press, said feeding unit comprising a lower shaft carrying a feed roll, an upper shaft carrying a feed roll, said upper roll being movable vertically relatively to the lower roll to interrupt the feed, a quick opening lifting arm for raising said upper roll, a detent for holding down said lifting arm when said H roll is voluntarily raised, means automatically moving said detent to release position, and a vertically reciprocating member adapted to engage said lifting arm during the operation of the press.

2. In a feeding mechanism for punch presses, a feeding unit comprising a lower roll, an upper roll coacting with the lower roll but movable vertically to interrupt their coaction, a quick opening arm adapted to raise the upper roll by the depression of the arm, a detent adapted to engage the depressed end of the arm, said detent automatically returning to non-engaging position when released, but retaining itsengagement by frictional impingement against the arm, and means reciprocating with the press, adapted to engage the end of the arm and depress it, thereby releasing the detent.

3. In feed mechanism for punch presses, the combination of feed rolls, separable to permit movement of the rolls and stock material independently one of the other, a lever controlling 4. In feed mechanism for punch presses, the combination of feed rolls, separable to permit relative movement of the rolls and stock material independently one of the other, a roll opening lever controlling the opening movement of said rolls, a manually operated cam shaft controlling said lever, and a detent adapted to be voluntarily moved independent of the cam shaft, mounted on said cam shaft in position to engage the lever when in roll-opening position.

5. In feed mechanism for punch presses, the combination of feed rolls, separable to permit relative movement of the rolls and stock material independently one of the other, a roll opening lever controlling the opening movement of rolls, a cam movable into engagement with said lever to displace the lever in the roll-opening direction and remaining in engagement with the &

lever to continue said opening, and means operating the cam from the reciprocating part of the press, said means having adjustment to cause the cam to impart opening movement to the lever during a part of the stroke of the reciprocating 861 imparts roll-opening movement to said lever, a 9Q concentric surface on said cam through which it continues in engagement with the lever to hold the rolls open, and means whereby said cam is driven in coordination with the working strokes of the plunger of the press. 9&

8. In combination with a punch press having a reciprocating member, a feeding unit comprising a lower and upper roll, said upper roll coacting with the lower roll but being mounted for movement vertically to interrupt their coaction, a quick opening arm adapted to raise the upper roll by depression of the arm, a detent adapted to engage the depressed end of the arm to thereby hold the rolls separated, said detent retaining its engagement by frictional impingement against the arm but being automatically returned to non-engaging position when released, and. means actuated in timed relation with the reciprocations of said member and adapted to depress the arm to thereby release the detent. 11m

9. In combination with a punch press having a reciprocating member, a feeding unit comprising rotatable. co-acting rolls, a drive shaft for said feed rolls, a one-way drive clutch on said shaft, and means receiving actuation from the 15 reciprocating member for rotating said clutch to cause intermittent rotation of said shaft and said rolls, said rolls being separable to interrupt their co-action, a roll opening lever controlling the opening movement of said rolls, a cam movable into engagement with said lever to displace the lever in the roll opening direction and remaining in engagement with the lever to continue said opening, and means actuating the cam in timed relation with the reciprocating member of the press, whereby the driving impulse to the drive shaft to cause rotation of the rolls occurs in timed relation with the opening and closing movements of the rolls.

10. In combination with a punch press having a reciprocating member, a feeding unit comprising rotatable co-acting rolls, a drive shaft for said feed rolls, a one-way drive clutch on said shaft, and means receiving actuation from the reciprocating member for rotating said clutch to 35 cause intermittent rotation of said shaft and said rolls, said rolls being separable to interrupt their co-action, a roll opening lever controlling the opening movement of said rolls, a cam movable into engagement with said lever to displace the lever in the roll opening direction and remaining in engagement with the lever to continue said opening, and means actuating the cam in synchronism with the working strokes of the reciprocating member of the press, the driving impulse to said drive shaft to cause rotation of the rolls occurring alternately with the actuation of the lever in a direction to open the rolls and interrupt their co-action.

/ FREDERICK J. LITTELL.