US3376634A - Methods of and apparatus for punch forming and separating pieces from a strip of material - Google Patents

Description

April 9, 1968 F. v. BROSSEIT METHODS OF AND APPARATUS FOR PUNCH FORMIN AND SEPARATING PIECES FROM A STRIP OF MATERIAL 2 Sheets-Sheet 1 Filed Oct. 19, 1965 mwb WW5 mm v M INVENTOR F. V Brosseh ATTORNEY usaasurasuna ud i 9, 1968 F. v. BROSSEIT 3,376,634

METHODS OF AND APPARATUS FOR PUNCH FORMING AND SEPARATING PIECES FROM A STRIP OF' MATERIAL 2 Sheets-Sheet f.l

Filed Oct. 19, 1965 FIG. 5

FIG. 4

F. V. Brosseir M-J FIG. 7

FIG.6

ATTORNEY 3,376,634 Patented Apr. 9, 1968 3,376,634 METHODS F AND APPARATUS FOR PUNCH FORMING AND SEPARATING PIECES FROM A STRIP 0F MATERIAL Fritz V. Brosseit, Kansas City, Mo., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Oct. 19, 1965, Ser. No. 497,718 Claims. (Cl. 29-428) ABSTRACT OF THE DISCLOS A fiat strip of getter material is intermittently advanced through a punching and inserting apparatus while a series of transistor cans is advanced in a path which is spaced from, parallel to, and in the same direction as the advancing strip of getter material. A reciprocating punch severs successive sections from the strip and returns each severed section to the strip whereafter each subsequent advance of the strip moves each severed section into alignment with an inserting device. The inserting device operates in unison with the punch to remove each severed section cfrom the strip and deposit it in an aligned can.

This invent-ion relates generally to methods of and apparatus for punch forming and separating pieces from a strip or web of material. In a more particular aspect, the invention deals with methods and apparatus of such character which provide also for assembling the separated pieces with other components in conjunction wit-h the separation of the formed pieces from the strip or web.

While the subject matter of the invention has utility in many fields, the principal utility contemplated at the present time is in the manufacture of transistors, and more particularly in the assembly of a disc of getter material into a transistor can.

As is known, it is common practice to place a getter substance in a transistor can prior to assembly of a transistor header with the can. The getter serves to take up undesirable vapor and gases, and to maintain the interior of the can in proper condition. In the past, getters have comprised small solid or doughnut-like pieces of a highly hygroscopic material which have had to be individually loaded into the cans and stabilized in a fixed location by a locking member, usually a wafer spring which interlocks with the interior wall of the can by friction. The handling and proper assembly of these parts has been a difiicult and relatively time consuming task, requiring specialized and rather complex equipment. Jamming and breakage often occurred.

An important object of the present invention, as related to the manufacture of transistors, is to provide a method of incorporating getter material into transistor cans in which the problems present in existing equipment and methods are avoided. In the method of the present invention, the getter component is made by punch forming a disc from a strip of fibrous getter material. The disc is then returned to the strip and is carried by movement of the strip into an aligned position with respect to an open transistor can. Next, the disc is separated from the strip and is pushed into the can with a simple reciprocal move ment of a plunger or other suitable instrument. The method lends itself especially to a substantially continuous operation, the cans and strip moving with one another through a punch forming and then an assembly zone, in which the discs are first punch formed and then inserted into the cans.

:In a broader aspect, an object of the invention is to provide a simple method by which individual pieces of a selected shape can be sequentially cut from a web or strip of material, and then conveyed to and deposited at a location remote from the place of cutting. The method can be applied not only with fibrous webs, but also with webs or strips of other materials such as thin metal sheets.

Another object of the invention is to provide apparatus especially suitable to carrying out the method steps of the invention. In its preferred form, this apparatus features a set of punches for blanking out pieces from a web or sheet. The punches cooperate with spring-biased shedder members located on the side of the sheet opposite from the punches, which permit the necessary displacement of the pieces from the web during punching and which return the pieces to their original positions in the web on withdrawal of the punches. The web is then advanced to carry the precut pieces from the punching zone to an assembly zone, where reciprocal pusher members operate to push the pieces from the strip and into transistor cans aligned therewith.

A further object of the invention is to provide apparatus of the character described which provides for synchronized advancement of a web of getter material and a row of transistor cans, sequential punching of discs of getter material from the web, and insertion of the precut discs into the cans. A feature of the invention in this respect resides in the arrangement by which a single reciprocable die head can be employed to carry both the punches and the pusher members, the latter serving to separate the discs from the web following the punching operation.

Other objects, advantages and features of the invention, will be apparent from the following detailed description of a specific embodiment thereof, when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view of a preferred apparatus according to and for carrying out the method of the invention, the showing being partially schematic;

FIG. 2 is a sectional view taken generally along line 22 of FIG. 1 in the direction of the arrows;

FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 2 in the direction of the arrows, parts being broken away for purposes of illustration;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3 in the direction of the arrows; 7

FIG. 5 is a greatly enlarged, fragmentary sectional view taken in the area included within the circle 5 in FIG. 2;

FIG. 6 is a schematic representation illustrating the initial step in removing a disc from the web and pushing it downwardly toward a transistor can;

'FIG. 7 is a view similar to FIG. 6, but showing the entry of the disc into the can; and

FIG. 8 shows a completed transistor can, part of the wall being broken away to show the getter material in its final lodged position in the can.

Referring now to the drawings, and initially to FIG. 8, the illustrative embodiment of the invention concerns methods and apparatus for forming and assembling the discs of a fibrous getter material with transistor cans. A completed transistor having a disc therein as shown in FIG. 8, the transistor can being identified by the numeral 10, the disc 11, and the transistor header 12.

Referring to FIGS. 1 and 2, the material from which the discs are formed comprises a strip or web 13 of tibrous material having the property of vapor and gas absorptiveness. Conveniently, this web may be a flexible web and composed principally of glass fibers bonded to one another in reticulated arrangement and carrying an active agent such as activated carbon.

A portion of the web is carried in roll form on a feed reel 14 mounted for rotation about a fixed horizontal axis. A power driven take-up reel 15 is located at the other end of the apparatus. Between reels 14 and 15, the web is guided by the guide rolls 1616 and 17-17. For

some applications, it is preferred to drive the rolls 1616 to provide positive feed of the web 13 through the apparatus. The reels and rolls are shown for purposes of illustration as each being journaled at one end in a frame plate F. However, it will be evident that supports can be supplied by any convenient type of framework and bearings, the objective being to mount the reels and rolls for rotation about stationary axes.

Located between the feed and take- up reels 14 and 15 is a work station comprising a punch and die assembly 18, through which the web is guided during operation. This assembly includes a platform 19 on which is carried a stationary die block 20. The block 20 has a horizontal upper surface over which the web 13 is moved, as will be described. A combined stripper plate and punch retainer 21 is superposed on the block 20, being secured thereto in any appropriate manner, as by machine bolts 2222. The lower surface of the plate 21 is cut away to form a channel which provides, with the top surface of the block 20 a horizontal slot 22a of sufficient width and thickness to. accommodate the web 13 for movement therethrough as the take-up reel 15 is advanced.

Positioned above the plate 21 is a punch holder 23, which is supported for vertically guided reciprocation by a plurality of upright posts 24-24. The punch holder 23 is secured to a punch shank 25, which in turn is connected with any conventional reciprocation means (not shown).

The punch holder carries a plurality of punches 2626, in this instance four, which are arranged in a row extending transversely across the holder 23, the location of each punch member being represented in FIGS 1 and 2 by a cap member 26a. The punches are guided in appropriate registering passageways 21a21a, one of which is shown in FIG. 5, formed in the plate 21.

At a second work station the punch holder 23 carries a series of parallel, transversely aligned pusher elements 2727 spaced from the punches in the direction of movement of the web 13. The number and lateral spacing of the pusher elements are the same as those of the punches, the location of the pusher elements being identified by cap members 27a27a in FIG. 1. However, it will be noted that the pusher elements are of substantially greater length than the punches, as shown in FIG. 2, and that when the punch holder 23 is in its down position with respect to the die block 20, the pusher elements extend downwardly through vertical passageways 20a formed in the die block and located below and in alignment with the pusher elements.

Referring now to FIG. 5, each punch 26 has associated therewith a shedder assembly 28, which is located within the die block 20. Each shedder assembly includes a shedder piston 29 received in a bore 30 which opens into the top surface of the block and is aligned with the punch 26. The shedder piston has an enlarged head 31 secured to or formed integrally therewith this being reciprocably received in the enlarged counterbore 32. A threaded plug 33 closes the lower end of the counterbore. A compression spring 34 is interposed between the plug 33 and the head 31 and serves to bias the shedder piston upwardly. The counterbore 32 forms with the bore 30 an annular shoulder 35 which serves as a stop against which the head 31 seats to limit upward movement of the shedder under the influence of the spring 34 upon retraction of the punch. The length of the shedder piston 39 is substantially equal to or slightly less than that of the bore 30, so that the upper end of the piston lies at or below the plane of the top surface of block 20 when the shedder is in its uppermost position.

Located below the getter web 13 and passing through the lower portion of the punch and die assembly 18 are the upper passes of four side by side roller link chains 36-36, best illustrated in FIGS. 3 and 4. The chains 36-36 are trained respectively over sprocket wheels 37-37 carried on horizontal shafts 38 and 39 located near-the opposite ends of the apparatus. The sidewise spacing of the chains 36--36 with respect to each other is equal to the spacing of the punches 26-26 and pusher elements 2727 in their rows, and each chain can thus be located vertically below a set of punch and pusher elements, as illustrated in FIG. 2. The block 20 is slotted, as indicated by the character 20b, to receive the upper passes of the chains therethrough. The chains are provided with link sections 36a36a disposed to receive therein upended transistor cans 1010, which are deposited therein from a feeder assembly. For some purposes, it is preferable to utilize separate holders or canriers for the workpiece which are attached to the chains with brackets, instead of feeding the workpieces directly into the chain sections 36a36a as illustrated.

While various can-feeding arrangements may be used, for purposes of illustrating the present invention the arrangement shown schematically in FIGS. 3 and 4 has been selected. In the illustrative feeder assembly, a feed hopper 40 of conventional construction is provided, having forwardly and rearwardly sloping inside walls 40a and 40b which converge toward a bottom opening 41. Positioned below the opening is a horizontally reciprocable grate member 42 carried by a horizontal rod 43 which in turn is slidably received in a suitably bored stationary bracket 44. The rod projects rearwardly from a block 45 secured to the the under side of the grade member. A

coil spring 46 encircles the rod and biases the grate to the left as viewed in FIG. 4. A stop pin 47 is located on the rod 43, to engage with the support bracket 44 and thereby limit the travel of the grate to the left.

Positioned below the grate member is a cross shaft 48 on which is mounted a camming Wheel 49 having a plurality of circumferentially spaced camming projections 50-50. The camming projections are designed to engage successively with a horizontal lug 51 projecting from the side of block 45, to deflect the grate 42 momentarily to the right and then release it for spring back under the influence of the spring 46,.The stop pin 47 brings the leftward movement of the grate 42 to a sharp stop by engagement with a confronting portion of the bracket 44. The shaft 48, which carries the camming wheel 49, is driven through a gear 52 at one end which meshes with a gear 53 on the end of the sprocket-wheel shaft 39.

The grate 42 is provided with a plurality of parallel elongated slots 5454, which are open at the left end as viewed in FIGS. 3 and 4. The slots are slightly greater in width than the barrels of the transistor, cans, in order that the can barrels can enter the slot with the can flanges resting upon the top surface of the grate on either side of the slot. In the present embodiment, there are four such slots, these being so spaced that the slots are aligned with and above the conveyor chains 3636.

Repeated reciprocations of the grate load the slots 5454 with rows of cans 10-10, the cans entering the grate slots through the opening 41 in the bottom of the hopper. The repeated reciprocations of the grate serve to discharge the cans from the open slot ends and into the can-receiving links of the chains.

Motion is imparted to the chains 3636 and the web 13 by any suitable drive mechanism which will produce intermittent step-wise advancement of the web and chain through the punch and die assembly. In the illustrated embodiment, a motor 55 is drivingly connected with a transmission 56 which may be a Geneva-type drive mechanism. The output of the transmission 56 is connected through a drive chain 57 to a sprocket on the shaft 38. A gear 58 is mounted on the latter, this meshing with a gear 59 secured to a stub axle 60 which is journaled in the back of the frame plate F. A sprocket 61 is also mounted on the stub axle 60, and a chain 62 drivingly connects the sprocket 61 with a driven sprocket affixed to the take-up reel 15. Thus the take-up reel and conveyor chains are driven in predetermined synchronism with one another.

The conveyor chains 36-36 are constructed to receive transistor cans 10 as they are delivered from the end of the grate 42. As earlier noted, the chains are provided with link sections 36a36a which receive the barrel portions of the cans, the flanges of the cans seating on the upper edges of the can-receiving link sections when the cans are disposed therein. Thus, the cans are carried from the hopper 40 toward and through the punch and die assembly 18, and are subsequently discharged into a collector tray 62 by being pushed from the links of the chain by the teeth of the sprockets 37-37.

OPERATION In carrying out the method of the invention, the web 13 is intermittently advanced through the punch and die assembly 18. During the initial feeding of the Web into position and prior to each incremental displacement of the web thereafter, the punch holder 23 is raised to an open position where the lower ends of the punches 2626 and the pusher elements 27-27 are above the top surface of the web, thus permitting the advancement of the web. After the web has been advanced and is stationary, the punch holder is lowered in conventional fashion.

Dealing first with the punching operation itself, the punches 2626 descend through the web 13 and punch therefrom a set of four of the discs 11-11, in the manner illustrated in FIG. 5, depressing the shedder pistons 2929 against the springs 34-34. The combination of each punch 26 and spring-loaded shedder piston 29 holds the disc 11 securely and perfectly flat during and after the punching operation, and compresses the disc and thereby compacts the material and enlarges the diameter of the disc slightly. FIG. 5 illustrates the bottom of the stroke of one of the punches 2626, showing how the disc 11 is temporarily displaced from the web 13 at the end of the punching stroke. As the punches are retracted, the shedder springs 34-34 force the pistons 29-29 to move up with the punches 2626, with the discs 11-11 still compressed therebetween. This movement continues until the enlarged heads 3131 of the pistons strike the shoulders 35-35 in the die block 20, at which time the discs 11-11 have been returned to the web 13, snugly retained in the opening created by the punching. The enlargement in diameter of the discs 1111 effected during punching allows the discs to be securely held in the web, and permits the web to act as a stripping element for detachment of the discs from the punches.

Following each punching cycle, the web 13 is advanced. Since the discs 1111 have been returned to the web 13 by the shedder assemblies 2828, the discs will be advanced also and eventually will be moved into aligned position with and under the pusher elements 27-27, by which the discs are removed from the web when the punch holder is depressed. It will be evident that, during each reciprocation of the punch holder 23, it must be elevated high enough to lift the lower ends of the pusher elements 2727 above the upper surface of the web 13 so that the web can move freely into a position where the discs can be operated on by the pusher elements. Of course, the punches and pusher elements are elevated and depressed simultaneously, the length of the stroke being determined by the overall length of the pusher elements rather than that of the punches.

In the apparatus herein disclosed, the web displace ment for each stepwise advance is one-third the distance between the punches and the pusher elements. Stated otherwise, the spacing of the pusher elements from the punches is equal to three times the incremental displacement of the web during each stepwise advance. Of course, this can be varied as desired, the only controlling condition being that, when the web halts, a disc is aligned with each pusher element.

Referring to FIGS. 6 and 7, the discs 11 are removed from their carried position in the web by being pushed downwardly by the ends of the pusher elements. The pusher elements are centered with respect to the discs. Since in the assembly of getter material with the transistor cans it is desired to, in effect, wedge or compress the discs into the cans, the diameter of each pusher element is made slightly less than that of the disc element, as is the bore diameter of the passageway 20a below the web. The pusher element is also provided with a rounded, somewhat bullet shaped or ogival tip contour. As a consequence, and as best seen in FIG. 7, as the pusher elements move the discs downwardly in their respective passageways and into the cans therebelow, the discs are dished slightly and this condition is maintained as they are pressed into the can. The dishing of the discs places them in some flexural tension, and as a consequence the discs are difficult to dislodge from their seated positions in the bottom of the cans.

It will be evident that four transistor cans are loaded with each reciprocation of the punch holder 23 and that the web is advanced one step between reciprocations. Consequently, a pattern of holes 13a is formed in the web as it moves through the punch and die assembly. Once the getter web has been wound completely on the take-up reel, the feed and take-up reels can be reversed and the web fed through again. Obviously, also, by slightly shifting the web sidewise in a new run additional punching can be done in the web in order that a maximum amount of material is used from any given web.

A significant advantage of the sequential punching and inserting steps is that a sharp punch is necessary to make a clean cut of a disc or other shape from a fibrous web, but such a punch would damage the-transistor can or other article into which the cut piece is to be inserted if it were attempted to punch and insert the piece in a single operation. Conversely, the preferred inserting element, exemplified by the pusher elements 2727, should be slightly smaller than the disc and should have a rounded tip in order to cause each disc to be dished so that it may be securely forced into the can; thus, the inserting element could not be adapted for a punching operation. The combination of a punch with a spring-loaded shedder is especially effective in handling a fibrous web in that the disc is held perfectly fiat while being punched, is compressed to enlarge its diameter enough so that the disc can be forced back into the strip by the shedder and be securely held in place by the strip for advancement to the inserting station. When a noncompressible strip is being handled, such as a thin metal sheet, the cut piece may still be inserted securely back into the strip because of slight flaring of the aperture in the sheet left by the punching step. In this instance, it is preferred to adjust the stop position of the shedder such that it pushes the piece back into the strip an extremely small distance beyond center, which causes the piece to be securely held in the strip by friction resultant from the slight flaring. With this arrangement, thin metal sheets of the order of one ten-thousandth of an inch have been processed. Substantial savings are achieved by using the original strip as the carrier for the precut piece of material, and precise alignment of the piece at the inserting station is automatically insured.

While one specific embodiment of the invention has been described in detail hereinabove, it will be obvious that various modifications may be made from the specific details described without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for forming discs of fibrous material from a strip of material and inserting the discs into transistor cans, which comprises:

(a) a conveyor for moving open transistor cans in a linear path "between two points;

(b) a stationary die platform adjacent to said conveyor;

(c) a shedder mounted on the die platform;

((1) a punch aligned with the shedder, with its punching end normally spaced from the shedder;

(e) a reciprocable head carrying the punch and operable to move the punch into and out of punching relationship with the die platform and shedder, the shedder being operable to return a disc punched from thestrip back into the strip upon retraction of the punch;

(f) a pushing rod carried by the head and spaced laterally from the punch; and

(g) means for intermittently feeding a strip of material between the platform and the punch, and toward and past the pushing rod, the strip substantially paralleling the conveyor, the pushing rod being so located and formed as to operate during the punching stroke, to engage and displace a previously punched disc from the strip and to insert the disc into a transistor can on the conveyor.

2. Apparatus as recited in claim 1, wherein:

said die platform is formed with a passagewayaligned with the pushing rod and designed to guide the disc toward and into the can, the passageway being of slightly smaller diameter than the disc; and

the tip of the rod engageable with the disc is ogival in form to effect a dishing of the disc during its travel through the passageway and into a can.

3. Apparatus as recited in claim 1, wherein the conveyor comprises one pass of an endless roller chain, and the cans are engageable in the links of the chain.

4. Apparatus for forming discs of fibrous material from a strip of material and inserting the discs into transistor cans, which comprises:

(a) means for unwinding and rewinding a coil of fibrous material while providing an unwound strip of material between the wound and rewound portions;

(b) guide means confining the strip to a predetermined path of movement;

8 J (c) a reciprocable head having a punch means operable to punch successive discs of material from the strip; (d) shedder means cooperating with said punch means to return the punched pieces to the strip;

(e) pusher means carried by said reciprocable head t which is spaced from the punch and shedder means in the direction of movement of said strip and operable to push the discs successively from the strip; and (f) means operable to position transistor cans successively in alignment with the pusher means to receive the discs therefrom. 5. A method of inserting pieces punched from a strip of material into open containers, comprising:

intermittently advancing said strip through a first and then a second work station;

sequentially punching pieces from said strip advanced to said first work station;

returning said pieces to the vacant positions in said strip whereafter said pieces are advanced to the second work station by the advancing strip;

sequentially advancing containers to said second work station to position each successive container parallel to and perpendicularly spaced from the plane of said strip and in alignment with each advanced piece; and

sequentially moving each piece advanced to said second work station from its position in the plane of said strip and translating each piece perpendicular to the plane of said strip into each aligned container.

References Cited UNITED STATES PATENTS 1,331,884 2/1920 Sunback 113-1 RICHARD H. EANES, JR., Primary Examiner.

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