US2932428A

US2932428A - Slug feeder

Info

Publication number: US2932428A
Application number: US695054A
Authority: US
Inventors: Robert S Mcgranahan
Original assignee: Federal Mogul Bower Bearings Inc
Current assignee: Federal Mogul Bower Bearings Inc
Priority date: 1957-11-07
Filing date: 1957-11-07
Publication date: 1960-04-12
Anticipated expiration: 1977-04-12

Description

April 12, 1960 R. s. MCGRANAHAN 2,932,428

SLUG FEEDER Filed Nov. '7, 1957 3 Sheets-Sheet 1 FIG. I

FIG. 2

FLEXIBLE SHAFT CONNECTED TO SHAFT OF PUNCH PRESS April 12, 1960 R. s. MCGRANAHAN 2,932,428

sLuG FEEDER Filed Nov. 7, 1957 3 Sheets-Sheet 2 April 1960 R. s. MCGRANAHAN 2,932,428

SLUG FEEDER 5 Sheets-Sheet 5 Filed NOV. '7, 1957 FIG. 6

- related parts.

2,932,428 SLUG FEEDER Robert S. McGranahan, Hinsflale, 111., assignor to Federal-Mogul-Bower Bearings, he, Detroit, Mich, a corporation of Michigan I Application November 7, 1957, Serial No. 695,054

7 Claims. '(Cl. 221-"238) This invention relates to improved device for feeding disc-shaped articles into punch presses and the like, and for accurately positioning them there.

One object of the invention is toprovide a machine which can very rapidly and very accurately fee'd discshaped objects into a punch press and similar devices.

Another object of the invention is topr'ovide a machine that will very rapidly feed metal slugs into a punch press and accurately position them therein.

Another object of the invention is to teen slugs one at a time into a punch press and the like.

Other objects and advantages of the innvention wil appear from the following description of 'a preferred form thereof. 1,

Inthedrawings: V I

Fig. 1 is a top .plan view of a machine embodyingthe present invention shown adjacent a'p'unchfpre'ss, only nited States Patent a portion of the lower seating die in the punch press being shown and the remainder of the press being omitted. The size and the shape ofthe slugs fed through the machine are indicated by broken line circles.

- Figure 2 is an end elevational 'viewfo'f the machine looking towards the right of Figure 1 but not including the punch press. 7 Fig. 3 is a View in elevation and section'taken longitudinally of Fig. 1 showing the device. The liheis .generally along the line 5-5 in Fig. 1, but the position of the machine is different andsome parts, are not shown in section in order to clarify/their location andconst'ruction. Fig. 3 shows the positions of the parts prior to starting the device. g i I Fig. 4 is a view similar generally to Fig. 3, although some of the section indication has been taken at a different point in order to simplify the illustration, and a portion of the punch ,press is shown. A first slug is being pushed into the punch press 'while a second "slug is being moved out from under the stack of slugs.

Fig. 5 is a View taken along the 1ii1'e'55 in Fig. l and indicates the furthest advanced stage of the feeding device. Here the first slug has been fed into "the punch press (the positioning means beingomitt'ed in order to show more clearly the exact position assumed by the slug) and the second slug has beenpushed up into the ready position. H

Fig. 6 is a view similar to Fig. 5 showing the retur'n cycle with the punch press closed and the feeding apparatus retracting.

Fig. 7 is a view in perspective on an enlarged scale,

as compared with Figs. 1-6, of the 'teedin'g'fin'g'e'r which advances the slugs of the initial stack to the second feeding portionof the device. v v

Fig. 8 is a view in elevation and insectio'n of the finger of Fig. 7 mounted in the slide.

Fig. 9 is a fragmentary perspective viewjo'f a .po'rtion of the feeding deviceincluding the finger of Fig. 8 and An outline of a slugis indicatedin a broken line circle. Y

The device shown in the drawings represents a slug movement by a threaded member '28 which may be ro- 2,932,428 Patented 7 Apr." 1 2, 51960 teeding apparatus 10 located adjacent a punch press 11. Only-portions 'of the punch press 11 areshow'n, theremainder being'well khown in the art and not requiring illustration. Basically considered, the punch press 1 1 has a stationarylower die-member 1'2,fand a movable upper die 13. The upper die 13 is slidably mounted on a pair of guide rods 14 and is fixed at theeh'do'r" a reciprocating shaftjlS, springs :16 acting to cush on the die 13.

In atypical 'iasm'naabn of the punch press 111, the upper die 13 moves down into the lower die 12 and trims a slug S, usually while also forming it into some desired shape-for example, into a flanged case for an oil sealing device. The punch press 1 1 may cut out a smaller disc from the slug S, or it may cutout an annular blank, usually forming a flange thereon at the same time in a single stroke. In any event, ordinary machines of this kind ordinary feeding devices have tended to waste a great 'deal of the slug S, partly because the cuts were usually off center, so that a considerably oversized slug had to be used. This was partly because of inaccurate positioning of the slug. Moreover, where accurate positioning was obtained in the prior art, it was obtained at the expense of speed, and an important feature of this invention is that both accurate centering and speedy operation are obtained.

To cope with the speed of the feeder 10 and "to counteract the inertialtendency of the slug '8 to slide on :past the point whereitlshould come to rest, the lower die T2 is preferably provided with a pair of adjustable stop bars 17, each with a slot 18 through which projects a bolt 19 or other tightening member. The adjustment makes it slug S "quite "close to the stops 17.

I p The s1ug feeding apparatus lilinciudes a base frame 20 on which 'are mo'unted a plurality of

vertical guide members

21, 22 and 23, preferably three, to retaiiua "stack of the slugs S. The rear guide member 21 is pref- I erably made stationary to define the slug pickuppoint, while the two forward'

guide members

22 and 23 are mounted on movable bases 24 secured to a table 2 5. For example, Allenhead screws 26 may extend through a slot 27 in each base 2 1-, so that the

guides

22 and 23 can each move out along a line at 45 to the of movement of the slug S, their axes of movement converging at the rear guide 21. In this way, diserenrsizes of discs S can be accommodated. For this purpose, "and for accurate centering of the discs S, these two {

forward guide members

22 and 23 are linked for synchronous taneouslyioward the rear guide 21. The table 25 may be mounted on the frame 20 by similar Allen head screws 30 passing through longitudinal slots 31, so

' some adjustment may also be obtainedin that in her.

The table 25 also has a central slot .32 along which moves the reciprocating par'tsof the feeding device 1 0.

Afiexible shaft 33 may lead to a suitable power source (preferably the crankshaft or camshaft for the 'pu'iich press 11 thereby assuring synchronization), to a crankshaft 34 which is j'ournaled to the frame 20 and, in turn, drives a crank 35 which rocks a drank arm 36 pivoted at one end to thecrank 35. The other end of the arm 36 is pivotedjto a bracket 37 on the bottom of a sl'idii'ig member 38,-which may be a solid plate or may have v W p 2,932,428

3 holesin it for the sake of lightness, as shown in Fig. 3. The sliding member 38 moves in a guideway 39 beneath the table 25, supported by the frame 20 for true rectilinear movement back and forth in accordance with the rotation of the crankshaft 34 and the movement of the crank 35. This reciprocating member 38 is preferably bolted or otherwise secured to a narrow elongated upper member 40 which slides with it in the guideway 39. This upper member 40 includes a plate 41 threadably secured to it by screws 42 and projecting beyond it at its forward end.

This plate 41 comprises the forward or second stage of the slug-projecting or slug-feeding means. The member 40 is also provided with a recess 43 in which is mounted, as shown in Figs. 8 and 9, a pivoted pickup member 45, whose pivots 46 are journaled inopenings 47 in the member 40. The pickup member 45 is springmounted, as shown in the drawings, and is retractable behind a stack of slugs S in the

guides

21, 22, and 23. The perspective view of the pickup member 45 in Fig. 7 shows a preferable shape of the pickup member 45, with forward concave lip 50 adapted to engage the rear edge of one of the slugs S.

As shown particularly in Fig. 3, when the crank 35 is .in its rear position, the

slides

38 and 40 are in their rear position and the pickup member 45 lies just behind the stack of slugs S. At this time, one slug S falls by gravity down onto the slide member 41 and the side portions 51 of the member 40. A member adjacent the forward side of the stack of slugs permits the passage of only one slug at a time through it. The pickup member 45 itself is sufficiently thin-projecting less than the thickness of one slug above the member 41so that it does not tend to pick up a second slug.

Thus, as shown in Fig. 4, the pickup member 45 will pick up from the bottom of the stack one slug S and move it forward, while at the same time riding beneath the remainder of the stack of slugs as do the adjacent parts of the slide member 40. Thus, the pickup member 45 carircs the one slug S forward on the upper surface of the impelling member 41 and at the rear thereof, as shown in Fig. 4.

When the device passes from the position shown in Fig. 4 to that shown in Fig. 5, the slug S passes beneath a pivoted spring-urged dog 52 The passage of the slug S forces the dog 52 to swing up and compress its spring 53 against a bolt 54 secured to the frame. Thus, the dog 52 permits the slug S to pass, but after the slug S passes, the spring 53 forces it down behind it and when the pickup member 45 begins to retract, as shown in Fig. 5, the dog 52 engages the rear edge of the slug S to prevent further retraction holding the slug S in that position. There are also a pair of hold-down

arms

55 and 56 shown in Figs. 1, 2, and 5, pivotally connected adjacent their rear ends to a lateral bar 57 which is urged .downwardly by a spring 58 hearing against a bolt 59 secured to the frame.

The forward ends of the

arms

55 and 56 extend beneath a lateral hold-down bar 60. Thus,

during this stage and is prevented from retracting along with the sliding bar 41 and the pickup member 45 by the dog 52.

When, as shown in Fig. 6, the sliding member 41 and the pickup member 45 are reciproeated back, the slug S wil1 not be returned but will be held back by the dog 52,. and the spring-urged hold-down

arms

55 and 56 will gradually flatten out to hold the whole surface of it. The pickup member 45, however, slides back beneath the stack of members which have been held elevated by the As it retracts, it moves back into the position shown in Fig. 3. Meanwhile, the forward member 41 upon which the slug S was originally carried moves beneath it by virtue of its being never trapped by the dog 52 which trapped the slug S. The relative sliding movements shown in Fig. 6 terthe slug S is held down by the hold-down

arms

55 and 56 minates when the forward end 61 of the slide 41 passes beyond the dog 52 and the slug S then drops down in front of the forward end 61. This places it in the position indicated in dotted lines in Fig. 3.

Further forward movement of the device in the next cycle will not only pick up another slug S from the bottom of the stack, as shown in Fig. 4, and as already described, but will also, .as shown in that same view, begin projecting the first slug S forward in the position shown at the left-hand part of Fig. 4. Here the

holddown arms

55 and 56 prevent the slug S from being urged up vertically or tilted out of its flat position, while the forward edge 61 of the sliding member 41 impels it along a surface 62 upon and into the punch press 11. As shown best in Fig. 2, the surface 62 upon which it slides comprises a pair of spaced-apart members supporting its edges. As the device reaches the position shown in Fig. 5, it has been forced beyond the bed 62 into the punch press 11 and is thrust forward upon the return of the slide feeding member by virtue of its own inertia. Then is when it is stopped by the stop members 17.

When the slide 41 is retracted in the second stage, the punch press 11 closes and the slug S is cut and formed as desired. It will be noted that the apparatus works in synchronization with the punch press by virtue of mechanism well-known in the art which may be, for example, a synchronization of the camshaft or crankshaft shown in Fig. 2 with a similar crankshaft for the punch press itself. Preferably, the shaft 33 is provided with a breakaway coupling or clutch 63, so that if the machine jams, the clutch 63 will slip and the machine will not damage itself by running.

To those skilled in the art to which this invention relates, many additional changes in construction and widely differing embodiments of the invention will suggest themselves without departing from the spirit and scope of the invention as defined in the claims.

What is claimed is:

1. A device for feeding slugs into a punch press while accurately positioning them therein, said punch press having a cyclic power means, said device including in movement over said table surface and passing beneath said stack, said feeding member having an elongated plate, longer than the diameter of a slug with a forward end and a rear end and a pickup member projecting above said rear end a distance less than the thickness of a slug; means for reciprocating said feeding member in synchronization with the cycle of said punch press; means mounted above said table surface forward of said stack and above said elongated plate by a distance greater than the thickness of a single slug and less than the thickness of two slugs so that only one slug is fed at a time from the bottom of said stack; catch means positioned slightly forward of the forward end of said elongated plate when the latter is in its rearmost position, and barely rear of therear end of said elongated plate when the latter is in its forwardmost position, said catch means being yieldably mounted to permit passage therebeneath of a slug carried forward on said elongated plate by said pickup member but preventing its retraction with said pickup member so that it drops on said table in front of said forward end of said elongated plate when said plate is retracted and is later propelled along said table by the forward end of said elongated plate into said punch press; hold-down means for said slug as it is pushed by said elongated plate front end; and stop means in said punch press for limiting the movement of said slug into said punch press.

2. The device of claim 1 wherein said means for retaining the stack of slugs comprises a stationary rear vertical bar and a pair of forward vertical bars synsaid rear bar and from each other.

3. A device for feeding slugs into a punch press while accurately positioning them therein, said punch press having a cycling power means, said device including in combination a rigid frame having a table surface; a plurality of vertical guide means supported by said frame for retaining a stack of slugs above said table surface; a feeding member mounted for reciprocating sliding movement over said table surface and passing beneath said stack, said feeding member having an elongated plate, longer than the diameter of a slug with a forward end and a rear end, and a pickup member projecting above said rear end a distance less than the thickness of a slug; means for reciprocating said feeding member in synchronization with the cycle of said punch press, including a flexible shaft driven by said punch-press cycling power means and a torque converter for turning rotary movement of said shaft into reciprocating movement of said feeding member; a plate mounted above said table surface and above said elongated plate by a distance greater than the thickness of a single slug and less than the thickness of two slugs; a pivoted spring-urged dog positioned slightly forward of the forward end of said elongated plate when the latter is in its rearmost position, and barely rear of the rear end of said elongated plate when the latter is in its forwardmost position, said dog yielding to permit passage therebeneath of a slug carried forward on said elongated plate by said pickup member but preventing its retraction with said pickup member, so that it drops on said table in front of said forward end of said elongated plate when said plate is retracted and is thence propelled along said table by said elongated plate into said punch press; springurged hold-down means for said slug forward of said dog for holding down said slug as it is pushed by said elongated plate front end; and guide means on said punch press for receiving said slug as it is projected forward and limiting its movement in said punch press, so as to center it there.

4. The device of claim 3 wherein there are three of said vertical guide means, a rear stationary one and two forward ones mounted for simultaneous snychronous movement toward and away from each other and said rear one.

5. A device for feeding slugs across a stationary table surface from a stack of slugs held above said table surface, comprising a feeding member mounted for reciprocating movement over said table surface beneath said stack, said feeding member having an elongated flat portion, longer than the diameter of a said slug, with a forward end and a rear end; a pickup member pivotally mounted to said feeding member adjacent said rear end and yieldingly urged to project above said flat portion less than the thickness of a said slug; means for reciprocating said feeding member beneath said stack so that said pickup member can pick up one slug from the bottom of said stack, said feeding member then carrying said slug on said flat portion; means for preventing said pickup member from carrying more than one slug from said stack at a time; and yieldable catch means positioned slightly forward of the forward end of said elongated flat portion when the latter is in its rearmost position, and

barely rear of said pickup member when said feeding member is in its forwardmost position, said catch means yielding to permit passage therebeneath of a slug carried forward on said elongated fiat portion by said pickup member but preventing retraction of said slug by and with said pickup member so that said slug drops on said table in front of said forward end of said elongated portion when said feeding member is retracted and is propelled along said table by said forward end of said feeding member on its next stroke, said pickup member yielding to be substantially level with said elongated flat portion as it passes beneath said stack on each retraction of said feeding member.

6. The device of claim 5 wherein there is a yieldable hold-down means forward of and separately mounted from said catch means for holding down a slug therebelow as said slug is moved across said table beyond said catch by said forward end of said feeding means.

7. A device for feeding circular metal slugs, comprising a rigid table surface; means for retaining a stack of slugs above said table surface; a feeding member mount ed for reciprocating sliding movement over said table surface and beneath said stack, said feeding member being longer than the diameter of a said slug and having a fiat upper surface with a forward end and a rear end; a pickup member pivotally mounted to said feeding member adjacent said rear end and spring-urged to normally project up above said rear end a distance less than the thickness of a slug, said pickup member having an arcuate edge to engage said slug; means for reciprocating said feeding member; a stationary member mounted above said table surface with a clearance above said feeding member greater than the thickness of a single slug and less than the thickness of two slugs, so that only one slug at a time is fed from the bottom of said stack; yieldably mounted catch means positioned slightly forward of the forward end of said feeding means when the latter is in its rearmost position, and barely rear of the pickup member when the latter is in its forwardmost position, said catch means yielding to permit passage therebeneath of a slug carried forward by said pickup member on the flat upper surface of said feeding member but preventing retraction of said slug so that it drops on said table in front of said forward end of said feeding member when the latter is retracted and is then propelled thereby along said table on the next forward stroke of said feeding 1 member, said pickup member yielding downwardly as it passes below said stack on its return stroke; and springmounted hold-down means forward of said catch means for holding said slug down flat as it is pushed forward by said forward end of said feeding member.

References Cited in the file of this patent UNITED STATES PATENTS