US2392138A - Stock feeding mechanism - Google Patents

Description

Jan. 1, 1946. R. A. FREEMAN v 2,392,138

STOCK FEEDING MECHANISM Filed April 17, 1943 s Sheets-Sheet 1 INVENTOR RaymondAfreeman ATTORNEY Jan. 1, 1946. R. A. FREEMAN STOGKFEEDING MECHANISM 'Filed April 17, 1945 3 Sheets-Sheet 2 INVENTOR v Raymond lLFreeman ATI 'ORNEY n: 1, 946. R. A. FRE'EMAN 2,392,138

STOCK FEEDING MECHANISM Filed April 17, 1945 3 Sheets-Sheet 3 I 3' ATroNEY Patented Jan. 1, 1946 UNITED STATES PATENT OFFICE STOCK FEEDING MECHANISM Raymond A. Freeman, Hudson, N. Y., assignor, by mesne assignments, to The V 8a Press Company, Incorporated, Hudson, N. Y., a corporation of New York Application April 17, 1943, Serial No. 483,465

16 Claims.

This invention relates to stock feeding mechanisms and more particularly to improvements in mechanisms for intermittently feeding sheet stock, generally supplied in strip form, to punch presses to have the desired operations performed thereon.

In the operation of the more improved types of multiple tool, crank shaft actuated, punch presses used for quantity production, considerable time is required for the tools, es ecially horizontally acting tools, and for stop and safety devices, to be moved into operative position, a fact well known and recognized by the engineers, or others, in charge. Stock feeding mechanisms in general use, have been timed with respect to the rotation of the press crank shaft, or with respect to the reciprocating movement of the tool carrying slides. Such arrangements limit the time allowance for moving multiple tools,

stop, and safety mechanisms, to approximately g 180 degrees of the crank-shaft rotation. The

more complicated punch presses have been found to require more time for the action of these tools and mechanisms, and therefore, as one object of this invention,. it is contemplated to provide a stock feeding mechanism by the use of which more time than that allowed during 180 degrees of crank-shaft rotation, will be provided,

Another object of this invention is to provide, in combination with a crank-shaft actuated punch press of the above type, a stock feeding mechanism which will provide a time allowance for the operation of multiple tools, stop mechanisms, and safety devices of more than 180 degrees of one revolution of the crank-shaft.

Still another object is to provide a stock feeding mechanism, adapted to be actuated in timed relation with the actuation of a machine operating on the stock, wherein meansis included to allow less time for feeding the stock the required amount, forinstance during a time interval of less than one-half the time required for one complete cycle of the machine operation.

A further object of this invention is to pro.- vide an improved stock feeding mechanism for a machine, which is adapted to intermittently feed stock at timed intervals in respect to the operation of the machine and wherein means is provided to causea delayed action of the stock actuated. v

A still further object 'of this invention is to provide an improved form of stock feeding mechanism which'will be relatively simple in construction, inexpensive to manufacture, read ily manipulated, compact, and very efiicient and durable in use. 7

With these and other objects in view, which will appear as the description proceeds, there has been illustrated in the accompanying drawings a form in which the features' and principles of this invention may be conveniently embodied in practice, it being understood that various changes may be made within the scope of what is claimed, without departing from .the spirit of the invention. V 1

In the drawings:

Figure 1 is a front elevational view of a punch press having astock feeding mechanism-embody ing the features and principles of this invention associated therewith; I

Figure 2 is an enlarged side viewof the stock feeding mechanism of this invention;

Figure 3 is a topplan view of the same;

Figure 4 .is a brokenside view of the stock feeding mechanism similar to Figure 2 but with the parts thereof in a different operative position; v

Figure 5 is a partial front elevational view of a punch press and showing a somewhat modified method of actuating the stock feeding mechanism of this invention; and p a Figure 6 is a, partial front elevational. view of a punch press andshowing another modified method of actuating a somewhat modifiedform of stock feeding mechanism.

Referring to thedrawings, wherein like reference numerals designatelike partsthroughout the several views, the reference numeral H denotes the frame of a punch press in which a slide I2 is arranged to be reciprocated in the usual manner in ways l3 and Mby a crank shaft I5, rotated by being connected to a flywheel l6 which in turn is rotated by a motor driven belt (not shown), or by direct motor drive (not shown). A multiple. tool holding block 11secured to the lower end of the slide l2, carries tools I 8, l9 and 2| in cooperating relation .with suitable dies,,etc. (not shown) but mounted: in a die block 22 bolted to abase member 23 which extends outwardly from the frame I I. The stock feeding-mechanismpf this invention is shownassociated with the above described punch press and is adapted to intermittently feed stock 24 from a source of supply to the required position between the tools l8, I9 and 2| and the dies mounted in the die block 22. One cycle of the press, or machine, includes, in this instance, a down stroke of the slide I 2 from its extreme up-position, and an upstroke of this slide to its initial lip-position, all of which takes place during one revolution of the crank-shaft I5, and during the time interval required forthese slide movements, asafety device checks the. register bf the stock and acts to stop the press if the stock is not in register, the tools [8, I9 and 2| act upon the stock and are withdrawn enough to clear the stock, horizontally acting tools actuate, and a new portion of stock is fed into position.

The stock feeding mecha'nisin of this invention, whereby stock is fed tothemachine during less than one-half of the time interval required for one cycle of machine. operation, in-

cludes a base 25, herein shown securedupo ai side extension 26 of the machine basemember 23, a. shaft supporting flange 21 extending upwardly from the" base 25, a shaft 28 supported by and journaled in the flange 21, a gear 29 suitably secured to the inner end of the shaft 28, and a crank arm 3| keyed and clamped to the outer end of the shaft 28. The crank arm 3| is connected by a link 32 to a crank arm 33 which is mounted upon a shaft 34 for free rotation thereon.

The link 32 is pivoted toth'e crank arm 3| by a pivot pin ,35 and to the crank arm 33 by a pivot pin 36. A'pawl 31 is mounted on the inner end of the pivot pin 36 and a coiled spring 38 is provided on the pivot .pin 36 and: arranged to react between this pin and. the vpawl 31 to constantly urge th pawl downwardly against a toothed, or ratchet, wheel 39 shown keyed to the shaft 34. The shaft: 34 extendsthroughiandis journaled in a bracket 42 andspaced a'p'art upwardly extending frame members 43 and 44. The bracket 42 is secured upon the base member side extension 26. The . framemembe'rs 43 and 44 are also secured upon the side extension 26. Between the frame members 43 and 44, a roller 46 is secured to. the shaft '34. operates, to feed stock 24 fed therebetween, with a roller '41 secured to a shaft 48 which is journaled in and extends between bearing blocks 49 and which are slidably mounted in the frame members 43 and 44 respectively. An adjustable compression spring 52 is provided and arranged to act upon each of the bearing blocks 49 and 5| respectively, by reacting between'an adjusting nut 52a, screw threaded upon a stud 52b extending upwardly from each frame member 43 and 44, and a sleeve 52c engaging the respective bearing block 49 or 5|, whereby the required feeding pressureis applied to the stock 24 to properly feed it when the roller 46 is rotated.

To prevent the roller 46 from overrunning, an adjustable tension brake band 54 of the usual form may be provided. Means comprising an elongated bar 55 may also be provided to be manipulated either manually, or automatically,

The roller 46 cov 51 threaded into and extending downwardly, in this instance, from an extension of the slide I2 and comprising a short arm 58 secured to one side of the slide l2, whereby near the bottom of the down stroke of the slide [2, the roller 41 will be raised. The bar 55 intermediate its other end and the pivot 56 is disposed under an extended portion 49a of the bearing block 49 to engage the same to raise the roller 41 when the bar 55 is actuated either manually or by the screw 51. A cam lever 59 pivoted to the frame member 43 is adapted when manually swung into ahorizontal position, as shown in full lines in Figure 2, to engage the outer end of the bar- 55 to raise the roller 41. A spring catch 6| is arranged to releasably grip a pin 62 provided on the lever 59 to hold the lever 59 in bar raising position.-

Figures 1-5 inclusive show a vertically slidablc gear rack 63 having its teeth in mesh with the teeth of the gear 29 to rotate it when the rack isreciprocated up and down. The rack 63 is to raise the-roller 41 away from the roller 46 and P One end of the bar 55 is guided in ways 64 secured to, or formed in, the supporting flange 21. In Figures 1-4 inclusive the rack 63 is shown connected to the slide l2 through the short arm 58 by means of a threaded shank 65 extending from the upper end of the rack 63 and passingthrough the arm 58. Adjusting nuts 66 and 61 screw-threaded on the shank 65 and disposed one on either side of the arm 58 may be manipulated to verticallyadJust the rack 63 in respect to the slide l2, and to change its relationship with the gear 29.

The rack 63 shown in Figures 1-4 is reciprocated with the slide l2, while the rack 63 shown in Figure 5 is reciprocated from the crank-shaft l5 through an adjustable bar 68. One end of the bar 68 is connected to. the crank-shaft 16 through an adjustable crank arm 69 and the other end is connected to the rack 63 by a lug H. The arrangement in Figure 5 is such that whenever the crank-shaft I5is rotated the rack will be reciprocated in timed relation with the same and with the movements of the slide I 2. In the form shown in Figurefi the shaft 28, to which the crank-arm 3| is secured, has an arm 12 secured thereto in place-of the gear 29. The

arm 12 is connected .by a jointed connecting bar 18 to a, ring'l3 which rides on an eccentric plate 14 secured to,. and rotatable with, the crankshaft l5, whereby the shaft 28 will be rocked in timed relation with the rotation of the crankshaft l5 and with the movements of the slide 12.

Referring particularly to Figure 4, the rack 63, the gear 29, the arm 3|, the link 32, the arm 33, and with the arm 33 the pawl 31, are shown by full linesin the position A, which they will assume when the slide l2, and with it the rack 63, is in'the lowermost position of its stroke. When in this position, the tooth engaging end 15 of the pawl 31 is positioned in back of one of the teeth 16, provided in the toothed wheel 39, in this instancefour teeth 16 being provided in the wheel 39. At this point in the cycle of machine operation, the slide 12, due to its connection'with the crank-shaft I5 is about to start its upward movement and most of the tools have performed their operation on the stock.

Under normal conditions the feed of stock would be started at this point and the stock would interfere with the tools not yet withdrawn to clear the stock. However, in the present instance, it is desired that the starting movement of feeding stock be delayed to allow the tools to clear the stock and still finish the feed of the stock at the top of 'the slide stroke so that there is time for the stop and safety devices to be actuated. The novel arrangement of the parts of the stock feeding mechanism of this invention is provided for this purpose.

While assuming the position A (Figure 4) the crank-arm 3| and the link 3i were moved from a position through their dead center position B. Whenthe gear 2% is rocked by the rack 63 during the first portion of the upward movement of the slide I2 and rack 63 the arm 3| and the link 32 must first move from position A through the dead center position B and to the position C before the pawl tooth engages one of the wheel teeth 16 to rock the roller 46 and feed stock.

It will be understood that during the time interval the slide I2 is moving from its extreme up-position to its extreme down-position, that is, during 180 degrees of crank-shaft revolution, no stock 24 is being fed, and the pawl 31 is being retracted about the wheel 39. In addition to this period of no feed there has been added the time interval during which the arm 3| and the link 32 are approaching and passing their dead center position B, and while the slide 12 is being given the first portion of its upward movement by the crank-shaft i5. This delayed action of the pawl 37 upon the wheel 39 and through the shaft 34 to the roller 46 to feed stock, allows additional time for the more complicated tools of modern production methods, especially horizontally moving ones, and stop and safety devices, to be actuated, and thereby increases the efi'iciency of machines in which the mechanism of this invention is structurally included. This delayed action or overtravel occurs near dead center" of the arm 3| and the link 32, thus making a, small amount of overtravel of the pawl correspond to a large angular motion of the gear 29 and of the shaft [5. It will be noted that to obtain the results desired in the mechanism illustrated the arrangement is such that the arm 3! rocks in a direction opposite to the direction the arm 33 rocks thus adapting the arm 3| and the link 32 to pass and repass their dead-center position during one cycle of the rocking movement of the arm 3 I.

The stock feeding roller drive comprising the above disclosed combination and novel arrangement of the arm 3| and the link 32, the pawl 31 and the toothed, or ratchet, wheel 39, forms a means to provide a delayed action of the rollers on the stock to be fed, and provides an increase in the actual machine operating time and decreases the tim for stock feeding during a time interval of less than one-half the time required for one complete cycle of the machine, or less than one-half the time interval for one revolution of the crank-shaft. By the use of the arrangement illustrated, stock may be fed during as little as 110 degrees of one revolution of the crank-shaft, thus giving an added time allowance of '70 degrees of crank-shaft rotation in other forms without" departing from the spirit or essential attributes thereof and it iatherefore, desired that the present embodimentlbe considered in all respects asillustrative, and'not restrictive, reference being had to the claims rather than to the foregoing description to indicate the scope of the invention.

Having thus fully described the invention, what is claimed as new and for which it is desired to secure Letters Patent, is: r

1. In a punch press the combination of a tool carrying slide adapted to 'bereciprocated 'by a rotating crank-shaft, and mechanism for feeding stock to the tools carried by said slide, said mechanism including a pair of cooperating stock feeding rollers, means to rotate one of the rollers including a toothed wheel and a pawl adapted to. engage the teeth of said wheel, a rockable arm to which th pawl is connected, and means to rock said arm to first retract the pawl about the wheel and then cause the pawl to engage a tooth on the wheel to rotate it, including connected arms adapted to pass and repass their dead-center position during one cycle of operation, means actuated by the crank shaft to rock one of the arms to cause them to pass their dead center position while the pawl is being retracted and to pass their dead center" position before the pawl engages a tooth on the wheel to rotate it. w

2. In a stock feeding mechanism, a pair of cooperating rotatable stock feeding rollers, means to rotate one ofuthe rollers including a toothed wheel operably connected to said roller, a first swingable arm having a pawl connected thereto and adapted to engage the teeth on the wheel to rotate it when the first arm is swung in one direction, a second swingable arm connected to the first arm and adapted to be swung in timed relation with reciprocating tools of a machine operating upon the stock, aid first and second arms being arranged to pass their "dead center position when the second swingable arm is swung in one direction to retract the pawl and to repass their dead center position when the second arm is swung to move the pawl into its toot engaging position to rotate said wheel. 7 V 3. The combination in a punch press, of a crank-shaft, a tool carrying slide adapted to be reciprocated by said crank-shaft, a pair of co operating stock feeding rollers, and means to rotate a first one of said rollers to feed stock comprising, a toothed wheel connected to said first roller, a first swingable arm having a wheel tooth engaging pawl secured thereto, a second arm adapted to be rocked in timed relation with the rotation of the crank-shaft of the press, and alink extending between and connected to said first and second arms, said second arm and said link being arranged to pass their dead center" position to swing said first arm in one direction to retract the pawl in respect to the wheel and to repass their dead center" position to swing said first arm in the other direction to dispose the pawl in wheel engaging position to rotate it.

4. In a machine having a reciprocable tool carrying slide actuated by a rotatable crankshaft, mechanism to feed stock to the tools carried by said slide including cooperating rollers, and means to actuate the rollers to feed stock during an upstroke of the slide comprising a cooperating pawl and toothed wheel device connected to one of the rollers to rotate it, a swingable arm, means actuated during the upstroke of said slide to swingv said arm in one direction, and a link pivoted to said arm, operably connecting said arm to. said device and cooperating with said armto pass a dead center position during the last portion of; the downstroke. or the slide and to repass the dead-center" position during the first portion-of the upstroke of the slide and before the. device is actuated.

5. In a stock feedinglmechanism :a pair of cooperating stock feeding rollers;v altoothed wheel drivingly connected to one of the. rollers to rotate it, a pawl adapted to engage the. :teeth' on said wheel, a first arm 'swing'able aboutthe. axis of said wheel. and carrying said pawl, a second arm, meansto swing the second arm, and a link pivoted to and connecting the free endsof said first and second arms, said linkand the second arm being arranged to pass. dead center" in one direction when said first. arm is swung thereby in one direction to position said pawl in tooth engaging position and to pass dead center in the other direction when said first arm is swung thereby 'in the other direction to cause a time delay before said wheel is rotated by the movement :of said pawl to rotate the roller to feed stock.

-6. In a machine, arotatable crank-shaft, a stock feeding mechanism comprising a pair of cooperating stock' feeding rollers, a pawl and ratchet device connected to one of the rollers to rotate it to feed stock, a first arm for swinging the pawl ofsaid device about the ratchet of said device, a second arm spaced from the first arm,

means actuated by said crank-shaft to swing said second arm, a link connecting the free ends of said arms, said first and second arms being so positioned in respect to -each other that the said second arm and must pass their dead center" position in both directions during one revolution of the crank-shaft.

In a machine, a rotatable crank-shaft, a stock feeding mechanism comprising a pair of cooperating stock feeding rollers, a pawl and ratchet device connected to one of the rollers to rotate it to feed stock, a first arm for swinging the pawl of said device about the ratchet of said device, a second arm spaced from the first arm, a link connecting the free ends of said arms, a gear connected to said second-arm, a gear rackcooperating with said gear to rock it to'sw-ing' said second arm, and means actuated by said crank-shaft to move said rack to rock said gear.

8'. Ina machine, a rotatable crank-shaft, a stock feeding mechanism comprising a pair of cooperating stock feeding rollers, a pawl and ratchet device connected to one of the rollers to rotate it to feed stock, a first arm for swinging the pawl of said device about the ratchet of said device, a second arm spaced from the first arm, a link connecting the free ends of said arms, a gear connected to said second arm, agear rack cooperating with said gear to rock it to swing said second arm, means-actuated by said crankshaft to move said rack to rock said gear, and means to adjustthe relative operative position of said rack in respect to said gear to vary the stock feeding action of said rollers.

9. In a crank-shaft operated multiple tool punch press, a tool carrying slide reciprocated by said crank-shaft, a pair of cooperating stock feeding rollers, a toothed wheel drivingly :connected to one of the rollers to rotate it, a pawl adapted to engage the teeth on said wheel, a first arm swingable about the axis of said Wheel and carrying said pawl, a rotatable gear, a secondarm connected to said gear; a link pivoted to and connecting the free ends of. said. first and second arms, saidlink andsaid second arm being arranged to pass dead center in one direction when said second arm is swung in one direction by rotation of said gear and to pass "dead center in the other direction when said second. arm is swung in the other direction by said gear, a toothed rack cooperating with said gear to rotate it, and means to connect said rack to said slide for reciprocating movement therewith.

10. .In a crank-shaft operated multiple tool punch press, a tool carrying slide reciprocated by said crank-shaft, a pair of cooperatingstockfeeding rollers, 21 toothed wheel drivingly connected to one of the rollersto rotate it, a pawl adapted to engage. the. teeth on said wheel, a first arm swingable about the axis of said wheelzand carrying said pawl, a rotatable gear, a second arm connected to said gear, a: link pivoted to and con-. meeting the free ends of :said first and second arms, said link and said second am being arranged to. pass dead center" in one. direction whensaid second armis swung in one direction by rotation of said gear and to pass dead center! in the other direction when. said second arm .is swung in the. other direction. by said gear, a toothed rack cooperating with said gear to rotate it, means to connect said rack to said slide for reciprocating movement therewith, and means: to adjust said rack in respect to said slide. to vary the rotating movement of said gear and through it the stockfeeding action of said rollers.

11. In a crank-shaft Operated multiple tool punch press, a tool carrying slide reciprocated by said crank-shaft, a pair of cooperating stock feed. ing rollers, a toothed wheel drivingly connected to one of the rollers to rotate it, a pawl adapted to engage the teeth on said wheel, a, first arm swingable about the axis of said wheel and carrying said pawl, a rotatable gear, a second arm connected to said gear, a link pivoted to; and connecting the free ends of said first and second arms, said link and said second arm being arranged to pass dead center" in one direction when said second arm is swung in one direction by rotation of said gear to position said pawl in tooth engaging position and to pass dead center. in the other direction when said second arm is swung in the other direction by said gear to cause a. time delay before said wheel is rotated by the movement of said pawl, a toothed rack cooperating with said gear to rotate, it, and means to connect said rack to said slide for reciprocating movement therewith.

12. .In stock feeding mechanism, cooperating stock engaging and feeding rollers, means to rotate one of said rollers including a ratchet wheel operably connected to the said roller, a first arm pivoted at one end and carrying a pawl operatively engageable with said ratchet wheel to rotate it, a second arm pivoted at one end, means to swing said second arm in one direction about its pivot, a link having one of its ends pivoted to the other end of said first arm and having its other end pivoted to the other end of said second arm, said first and second arms being positionedin respect to each other that the first arm will be swung about its pivot by said second arm acting through said link in a direction opposite. to the direction said second arm swings about its pivot.

13, In stock feeding mechanism, cooperating stock feeding rollers, means to rotate one of the rollers including a ratchet wheel operably connected to the said roller, a first arm pivoted at one end and carryinga pawl operatively engages able ,with said ratchet wheel to rotate it, a second arm pivoted at one end, means to rock said second arm in one direction about its pivot, a link having one of its ends pivoted to the other end of said first arm and having its other end pivoted to the other end of said second arm, said first and second arms being positioned in respect to each other that the link and said second arm will pass and repass their dead center position where pivoted together to delay operative engagement of said pawl with said wheel to rotate it.

14. In stock feeding mechanism, a rotatable stock engaging roller, a ratchet wheeLconnected to said roller, a pawl adapted to engage and rotate said wheel in one direction, a first arm swingable in one direction to actuate said pawl to ensage and rotate said wheel, a second arm swingable in a direction opposite to the direction of swinging movement of said first arm, means to swing said second arxri, a link operably connecting said second arm with said first arm to transmit swinging movement from said second arm to said first arm, the link and said second arm being adapted to pass and repass their dead center position to delay actuation of said pawl by said first arm to engage and rotate said wheel during one cycle of the swinging movement of said second arm.

15. In a stock feeding mechanism, a stock feeding roller, a ratchet wheel connected to said roller, a pawl adapted to engage said wheel to rotate it and said roller, a swingable first arm to actuate said pawl, a swingable second arm, means to swing said second arm, means to delay pawl operating movement of said first arm including a link connecting said arms and pivotally connected to each, said link with said second arm being adapted to have the connecting point therebetween pass and repass dead center position during each swinging cycle of operation of the second arm.

16. In a stock feeding mechanism, a stock feeding roller, a ratchet wheel connected to said roller, a pawl adapted to engage said wheel to rotate it and said roller, a swingable first arm to actuate said pawl, a swingable second arm, means to swing said second arm, means to delay pawl operating movement of said first arm including a link connecting said arms and pivotally connected to each, said link with said second arm being adapt-

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