US2851979A - Transfer device - Google Patents

Description

Sept. 16, 1958 H. B. CHATFIELD TRANSFER DEVICE 4 Sheets-Sheet l Filed June l5, 1954 .im Elli! I l lill:

- mmm Y Sept. 16, 1958 H. B. CHATFIELD TRANSFER DEVICE 4 Sheets-Sheet 2 Filed June l5. 1954 llllllllllllllllllllll lli!) IIII Il H. B. CHATFIELD TRANSFER DEVICE Sept. 16, .1958 2,851,979

Filed June 15, 1954 4 Sheets-Sheet 3 124/25 @p53* /02 Lw /Z/ ATTORNEY Sept. 16, '1958 H; B. cHATFlELD 2,851,979

TRANSFER DEVICE Filed June l5. 1954 v 4 Sheets-Sheet 4 INVENTOR HenriyB, Chatelql ATTORNE United States Patent O TRANSFER DEVICE Henry B. Chatield, Kinsman, Ohio Application June 15, 1954, Serial No. 436,880

` 3 Claims. (Cl. 113-38) The present invention relates to punching apparatus and more particularly to gang dies and novel feeding mechanism for advancing articles progressively along a row of dies and associated punches.

To progressively form a series of articles simultaneously, a long strip of sheet material may be fed past alined equally spaced dies in increments equal to the distance between the dies so that a series of punching operations can be performed on each article before it is detached from the strip. The use of such a method increases the rate of production but involves a large waste of material and is therefore costly. The present invention avoids this waste of material Without reducing the rate of production by feeding cut blanks to the first die and then moving the partially formed articles simultaneously from die to die during intervals between punching operations.

The article feeding may be effected by means of a series of grippers mounted on a reciprocable carriage for movement therewith in timed relation to operation of the punches, the grippers being adapted to carry each article from a die to the next adjacent die while the punches are retracted, to release the article, and to move with the carriage backto the former `die before the next punching operation. The grippers are preferably mounted on opposite sides of the dies for movement toward and away from articles alined with the punches and dies when the carriage is at opposite ends of its stroke.

Since each gripper must move into and out of the path of travel of the reciprocating punches and articles as it moves into and out of gripping position and must grip an article for a substantial portion of each operating cycle, the speed of the punches and the frequency of the punching operations must be limited Vto prevent the punches or the articles moved thereby from striking the gripper. If the punching machine is provided with a long punching stroke and is operated at a frequency of less than twenty strokes per minute, it is relatively easy to move each gripper out of gripping position before the punches are lowered against the articles. However, if the stroke is shortened and the frequency is increased, it is diicult to provide a reliable feeding mechanism which will operate satisfactorily for long periods of time.

According to the present invention the -grippers are moved into and out of gripping position extremely rapidly so as to permit reduction in the stroke of the punches and an increase in the frequency of the punching operations. The time required to move the -grippers into or out of gripping position is preferably less than about one-fortieth the time required to move the punches into and out of the dies and to complete -one cycle of operations so that the articles being formed may be gripped and released in the shortest period of time and at exactly the right instant. The machine of the present invention, due to the accurate and high speed operation of the grippers, can easily handle 50 or more articles per minute and can operate satisfactorily when the frequency is 2,851,979 Patented Sept. 16, 1958 greater than punching strokes per minute. Frequencies greater than strokes per minute are usually impractical since the metal pieces being deformed not having been annealed are apt to be torn or otherwise damaged and the punches are apt to be broken when the punches enter the dies at excessive speeds.

ln order to operate the gripping mechanism rapidly, the inertia and change of momentum of the grippers and the actuating mechanism therefor are minimized. The articles are preferably gripped by relatively light weight frangible gripping fingers mounted to reciprocate transversely of the gripper carriage. The fingers of the present invention are preferably actuated by a relatively light weight frame or actuating member that is mounted for movement with respect to the gripper carriage. rPhe actuating member is moved in timed relation to operation of the punches and actuates all the gripping lingers simultaneously when it is moved relative to the gripper carriage. However, it is preferable to provide a yieldable connection between the actuating member and each gripping finger so as to avoid backlash and damage to the gripper actuating mechanism and to permit independent movement of the gripping fingers due to dierences in the sizes of the articles being gripped.

The change in momentum of the gripper actuating mechanism may be minimized by providing gripping fingers which have less inertia than that of the actuating member therefor and/or by providing between the actuating member and the gripping fingers a speed multiplying connection, such as a snap-action mechanism or suitable gears or levers. It is preferable to mount the actuating member for longitudinal reciprocation relative to the gripper carriage and to move the gripping fingers transversely on the carriage while the gripper carriage is stopped at the end of its stroke by means of levers or the like between the ngers and the actuating member which reciprocate each gripping finger through a greater distance than the length of stroke of the actuating member relative to the gripper carriage.

rl`he gripper carriage and the actuating member are moved by separate actuating means in timed relation to the operation of the punches, the gripper carriage being reciprocated in a direction parallel to the rows of punches and dies and the actuating member being preferably moved relative to said carriage while the carriage dwells in stationary position at opposite ends of its stroke. The actuating member is preferably mounted on the carriage for longitudinal reciprocation therewith and is preferably reciprocated longitudinally relative to the carriage to actuate the gripping fingers. The carriage and the actuating member of the present invention are preferably moved by a pair of rotary cams which move the actuating member substantially in unison with the carriage when the carriage is moved in either direction longitudinally and which move the actuating member while the carriage is stationary at each end of its stroke. The cam that moves the actuating member to cause movement of the grippers may be operably connected to the punches to rotate through one revolution during each punching cycle and may be formed to move the grippers rapidly'into or out of gripping position while the cam rotates through an angle of about 6 or 8 degrees. By designing the cam inthis way it is possible during drawing of a cup-shaped article for the gripping fingers to grip the cup until an advancing punch starts to enter the cup and to `release the cup and move out of the path of the punch and cup before the punch engages the bottom of the cup. Likewise the cup may be gripped while it is being stripped from the retracting punch and before the end of the punch leaves the inside of the cup.

By mounting the gripping lingers so that they are acy but are preferably frangible to prevent damage to the gripper carriage, the -gripper actuating mechanism, and other parts Yof the feeding .mechanism when a punch strikes a gripping finger or when the fingers grip a broken punch caught in the stripper plate or in a die and attempt to advance `the saine. A frangible connection is preferred between 'the gripper Vcarriage actuating means and the gripping fingers so that the fingers cannot prevent move-7.

ment of the carriage actuating means.

Where a stationary stripper plate is provided to remove articles from the retractingpunches, there is danger that the gripping fingers will grip a broken punch projecting' hrough the opening in the stripper plate while the gripperv` carriage is being moved so as to effect a connection between the gripper carriage actuating mechanism and thel frame which supports the stripper plate. To prevent damage to the machine, it is preferable that this connection and/ or the connection between the gripping fingers and the carriage actuating mechanism be frangible, for example, by providing frangible gripping fingers or other frangible members. The gripping fingers may be made of a hard brittle metal so that they will break before they prevent movement of the gripper carriage or otherwise damage the machine but will last for thousands of punching operations when the machine is operating properly. If desired suitable safety mechanism may be provided to *stop the machine automatically when a punch or a finger breaks or when an article is not removed from a die and properly gripped by the gripping fingers. By the use of such safety devices and rigid frangible ingers which may be easily .replaced when broken, extensive shut-downs 'are 'avoided and `a high production rate may be'maintained.

The rotary cams employed for reciprocating the gripper carriage and the gripper actuating memberare preferably of a type which may readily be modified or replaced to vary the timing of the feeding mechanism with respect to the punches, the distance the grippers are moved, and/or the speed of movement of the grippers. It is preferable to provide cams having face grooves -formed by cam members vwhich may be removed and replaced or otherwise modified. The cam which operates the gripper actuating member is preferably provided with removable cam segments which may -be replaced with segments of differentA shapes to vary the operation of the gripping fingers.

An object of the present invention is to provide a vmachine which is capable of performing a series of progressiveoperations on afseries of articles advanced therethrough such as drawing, coining, sizing, piercing, trimming, etc. and which is capable of performing the operations automatically at maximum speed and with a minimum Aof ymaterial so as to minimize the cost of the operations.

A further object of the invention is to provide a high speed feeding mechanism which accurately positions the articles with 4respect to the punches and dies before each punching operation.

A still further object is to provide a high speed feeding mechanism that releases the articles being formed substantially simultaneously with movement of the punches against the articles and that grips the articles substantially simultaneously with stripping of the articles from the punches.

Another object of the invention is to provide a feeding device having gripping mechanism of lowV inertia which "may r'belreciprocatedatgeirtrernely high speeds.

A further object of the invention is to provide a high speed feeding mechanism for a punching machlne which is not permanently damaged by routine failure of moving parts or improper forming of articles and which can manufacture a maximum number of pieces before extensive repairs are required.

A still further object is to provide a high speed gripper actuating mechanism whose timing or speed may be readily adjusted with respect to operation of the punches.

Other objects, uses and advantages of the present invention will be apparent -fron'tihe following description and from the drawings in which: A n

Figure l is a front elevational view of a punching machine constructed in accordance with the present invention;

Figure 2 is a fragmentary vertical section on a larger scale with parts broken away showing a portion of the punching machine including the dies, the stripper, and the gripping fingers, the articles being shown in solid lines in the positions in which they are gripped shortly after they are stripped from-the punches;

Figure 3 is a fragmentary top Vplan view of the machine on a different scale with parts broken away, the grippers being shown in gripping position;

Figure 4 is a fragmentary side elevational view of the feeding mechanism shown in Fig. 3 with parts broken away and shown in section;

Figure 5 is a fragmentary vertical section with parts broken away on a larger scale and showing portions of the blank feeding mechanism;

Figure 6 isa vertical sectional view with parts broken away taken substantially on the line indicated at 6 6 1n Fig. 4 and on a larger scale;

Figure 7 is a vertical sectional view with parts broken away taken substantially on the line indicated at 7 7 in Fig. 4 and on the Asame scale as Fig. 6 showlng how the gripper carriage 'and the fra'rn'eme'mber are connected to their actuating pistons; r

Figure 8 is a fragmentary verticalsectional View taken substantially on the line indicated at 8-8 in Flg. 3 but on a larger scale and with parts broken away; D

Figur`e'9 is a fragmentary vertical sectional v1ew taken substantially on-the line indicated at 9-9 in Flg. 3 but on a larger scale and with'parts removed;

Figure 10 is a diagrammatic fragmentary plan v1ew on a reduced scale and with parts broken away to illustrate the general operation of the gripper carriage and the frame member sliding therein;

Figure 'll is an elevational view on an enlarged scale of the cam and follower actuating means for the carriage and the frame member when the carriage is Yat one end of its stroke and an instant after the gripping fingers are retracted, the follower and a portion of the cam for the gripper carriage being shown in dotted'lines;

Figure l2 is an elevational viewsimilar to Figure ll but showing the'cams in'fheir'po'stions'when the carriage is at`the opposite end of its"strokeandan instant before the gripping lingers are advanced to gripping position; and

Figure 13 is a fragmentary plan view showing details of the feeding mechanismisho'wn in Fig. 3 but on a larger scale and with parts broken away and shown in section,

' the position of the parts when the grippers are completely retracted being shown vin solid lines and the position of one gripping finger and the lever 'connected thereto when an article is .gripped being shown in dotted lines.

Referring more particularly to -the drawings in which like parts are identified with the same numerals throughout the several views, Figure 1 Vshows a progressive punching machine includingastationary upright frame 1 having a lower base portionZ, an upper-head portion 3, and an intermediate portion including an elongated horizontal table 4 which rests yon andprojects outwardly from the base vportion 2. The'table provides a rigid support for a row fof longitudinally-aligned equally-spaced dies to 1'1 which are held in fixed position with their upper edges substantially in a single plane. The head portion 3 of the frame provides a rigid support for a iiywheel 12 and for a punch holder 13 which carries a row of longitudinally alined equally spaced punches to 21, each in axial alinement with one of said dies.

The flywheel 12 is mounted on a crankshaft 22 for continuous rotation on'the head 3, and the punch holder 13 is slidably mounted between opposed vertical ways 23 and 24 for reciprocation vertically toward and away from the dies carried by the table 4. A motor or other suitable driving means is provided to continuously drive the flywheel in one direction, and a driving connection such as a crank and connecting rod or the like is provided to convert rotary motion of the flywheel into reciprocation of the punch holder. As herein shown, the cranksl'iaft 22 is journaled in the head 3 and has an integral crank pin or eccentric which is journaled in the upper end of an oscillating connecting rod whose length is adjustable to vary the vertical position of the punch holder. The connecting rod 25 has a ball and socket connection 26 to the punch holder 13 so as to permit oscillation of the connecting rod as it moves the holder vertically.

By adjusting the length of the connecting rod 25, the distance that the punches move into the die cavities can be closely controlled. The length of stroke of the punches is fixed as determined by the distance between the axes of the crankshaft and the crank pin and is suiiicient to move the punches out of the dies the distance required to permit feeding of articles from die to die. in the punching machine shown in the drawings the bottoms of the punches are elevated a distance above the top of the dies at least several times the maximum lheight of the articles being formed so as to provide room from suitable gripping and stripping mechanism above the dies.

According to the present invention an individual blank is fed to the first die S during each rotation of the flywheel 12 and the articles formed from the blanks are progressively advanced from die to die so that a series of operations are performed on each article as it advances from the first die 5 to the last die 11. Each time the punch holder is moved by rotation of the iiywheel to its lowermost position and so long as the punching machine is full of pieces the following operations are performed simultaneously:

(a) the punch 15 enters the die 5 and draws a cup from a circular blank,

(b) the punch 16 enters the die 6 and redraws a cup received from die 5.

(c) the punch 17 enters the die 7 and performs a second redrawing operation on a cup,

(d) the punch 18 coins and sizes a cup shaped article in the die 8.

(e) the piercing punch 19 passes through a piercing ring in the bottom portion of the die 9 and cuts a circular slug from the article in said die.

(f) the punch 20 performs a chamfering `operation and further shapes the article in the die 10, and

(g) the trimming punch 21 passes through a trim ring forming the upper portion of the die 11 to cut excess material from the margin of the article and to eject the article downwardly through the die, the position of the article at the instant of cutting being shown in dotted lines in Fig. 2.

The articles shown in solid lines in Fig. 2 are shown in the positions they have shortly after they are stripped off the punches and gripped, it being understood that the punches will move upwardlya substantial distance from their position shown in Fig. 2 as the articles are advanced by the grippers and before the holder 13 reaches the top of its stroke. Before the punches are again lowered the articles are accurately advanced a distance equal to that between the axes of adjacent dies. The position of the circular blank fed to the die 5 and the position of the article advanced from the die 1G to the die 11 before lowering of the punches is shown in dotted lilies in Fig. 2.

Suitable discharge chutes are provided to remove slugs cut in the die 9 and finished articles cut or trimmed in the die 11. As herein shown, the table 4 is provided with inclined passages or chutes 27 and 28 leading from the lower end of the dies 9 and 11, respectively, to the exterior of the table. The positions of a slug and a iinished piece in the chutes are shown in dotted lines in Fig. 2. If desired an extension 29 may be provided on the frame to convey the finished pieces from the chute 28 to boxes or other article containers.

According to the present invention the pieces formed in the dies are lifted a predetermined distance out of the dies after each punching operation and are then gripped and advanced before the next punching operation. Suitabe means is provided to remove each piece from the die after each punching operation. The punches and dies may be designed so that the pieces cling to the punches as they are retracted and the pieces are pulled out of the die cavities by the punches. For example, each piece formed in the die 9 is removed therefrom by the punch 19. However it is preferable to provide suitable bottom ejectors below the die cavities so as to insure that the pieces areV properly removed from the dies at all times.

As herein shown, each of the dies 5, 6, 7 and 8 is provided with an ejector rod or plunger mounted on the table 4 for reciprocation along the axis of the die. The upper portions of the plungers 130 have a diameter substantially less than that of the die cavities and engage the bottoms of the cup-shaped articles formed in the dies. A similar ejector rod or plunger 131 is provided for the die 1t) and is mounted like the plungers 130 coaxial with said die. The plunger 131 is the same as each plunger 130 except that the upper portion thereof carries an -enlarged head 132 which slides in the die 10 and has yan external diameter greater than the inside diameter of the sleeve-shaped article formed in the die.

Each of the ejector plungers 130 and 131 is provided with a circular flange 133 and is biased toward the punches by an ejector spring 132. The article engaging face of each plunger 130 is preferably shaped to conform to the shape of the article being formed and as herein shown is fiat so as to resist tilting of the article as it is advanced into or ejected from the die. The upward movement of the plunger 130 and 131 is limited by the iianges 133 as shown in Fig. 2, but the plungers are free to move downwardly when engaged by an article being advanced into the die. Since each ejector plunger engages an article when it iirst enters a die and aids in positioning the article as it is being deformed, each plunger improves the accuracy of the forming operations. It will be understood that each plunger is accurately guided for reciprocation in suitable bores so that tilting of the plungers is avoided.

Suitable stripping means is provided to remove the pieces from the punches after they have been raised a predetermined distance above the dies and suitable grippers are provided to grip the pieces substantially simultaneously with stripping of the same from said punches. The pieces may be stripped at the proper time by stripping means carried by the punches or by the grippers but it is preferable to mount the strippers on the stationary frame independently of the grippers and punches.

As herein shown, a horizontal stripper plate 30 is mounted on the table 4 and has a stationary position a iixed distance above the dies at the instant it is engaged by the pieces being raised by the punches. This stripper plate has a row of longitudinally alined equally spaced circular openings, each coaxial with a punch and die. Each opening has a diameter greater than the maximum diameter of the punch and smaller than the maximum diameter of the piece formed by said punch so as to permit advancing of the punch into the die and to strip pieces from the punch as the latter is retracted. The stripper plate 30 is shown herein as being stationary, but

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-it may be mounted formovement downwardly when the punches Jare lowered so longas itstrips the pieces from -thepunches substantially `as shown in Fig. 2.

The stripper plate is :also shown in position above `the die 11 to insure removal from the punch of any scrap VVring which maybe formed during trimming. However, this -portion of the stripper plate may be omitted and Qreplaced by-a spring-pressed stripper sleeve mounted on -the punch 21 since the scrap ring may be stripped from `the punch at any time.

-driven in timed relation tothe operation of the punches to 21 so as to advance a separate -blank to the first die 5 and to advance Veach piece from one die to the next adjacent die while thepunches are retracted. The

`pieces are advanced by light weight gripping fingers 31 and the blanks are advanced by a feed plate 32 in timed .relation to the rotation of the flywheel 12 and reciprocation of the punch holder 13. The feeding mechanism 4for controlling the grippingngers and the blank feed plate is driven from the crankshaft 22 by any suitable means, such as a sprocket and chain or suitable gearing. As herein shown, a sprocket wheel 33 fixed to the crankshaft .'22 is drivingly connected to a sprocket wheel 34 and an idler sprocket 35 by means of a link chain 36, the wheel 34 rotating once each time the crankshaft makes one revolution.

The sprocket wheel 34 is keyed to one end of the shaft 371so that the shaft is driven at a speed fixed with respect to the speed of rotation of the iiywheel 12. The shaft is journaled in a `stationary housing 38 carried by the table 4, said housing being rectangular in vertical cross section and having longitudinal side walls 39 and 40, a horizontal bottom wall 41, and a removable horizontal cover 42. The shaft 37 is carried by ball bearings 43 and 44 in the walls 39 and 4t), respectively, for rotation about a transverse axis preferably parallel to the horizontal axis of the crankshaft 22 and normal to the longitudinal rows of punches and dies.

The outer end of the shaft 37 is keyed to an externally cylindrical eccentric disc 45 to drive the same. An eccentric rod 46 has an internally cylindrical ring portion .47 rotatably mounted on said disc for oscillation thereon. Since the ringV portion 47 is eccentricand not concentric to the shaft 37, rotary movement of the shaft causes .reciprocation of the rod 46 and oscillation of a lever 48 that is pivotally connected at its lower end to the end of the eccentric rod 46. The lever 48 is drivingly connected to a lever 49 by means of a rotatably mounted pivot pin or shaft 50 that is keyed or otherwise connected to the levers for oscillation therewith about a fixed axis. The shaft 50 is rotatably supported from the table 4 by a bearing member 51 which is bolted to the underside of the table 4.

The upper end of the lever 49 is pivotally connected to one end of a yieldable connecting rod 52 by means of a yoke 53 and a pivot pin 54. The opposite end of the connecting rod is pivotally connected lin a similar manner to the upper end of a lever 55 which is rotatably mounted onthe table 4 for oscillation with the lever 49. The lever 55 is drivingly connected to a toothed gear segment '56 by means of a transverse pivot pin or shaft 57 which is keyed to said lever and said segment and is rotatably mounted to oscillate therewith about a fixed axis parallel to the shaft 37. The shaft '57 is rotatably supported on opposite sides of the segmental gear 56 by bearings 58 and 59.

An arm 60 is rigidly connected to the shaft 57 for oscillation therewith in unison and has an outer end extending below the table 4. The arm is drilled and threaded to receive an adjusting screw 61 which projects -opposite sides of the feed plate 32.

'from the outer end of the arm toward the bottom of the table and serves as an adjustable stop to limit oscillation of the segment 56 in one direction.

Slidably mounted on top of the table 4'is a flat rack member 62 rigidly connected to the feed plate 32 and having teeth meshing with the teeth of the gear segment 56 to convert oscillating movement of the shaft 57 into longitudinal reciprocation of the feed plate. The rack 62 is shown in its fullyretracted position in Fig. 5 and obviously cannot be advanced a distance greater than .that between its forward edge 63 and an upright edge 64 of the table. However, the screw 61 is preferably so `adjusted that the head thereof engages the bottom of the table 4 and prevents engagement of the edges 63 vand 64.

vSince movement of the lever 49 counterclockwise moves the adjustable stop 61 against the table ras shown in Fig. 4, the connection between the lever 49 and the lever 55 is preferably yieldable to permit movement of the lever 49 a short distance counterclockwise after the segmental gear 56 is stopped by the screw 61. AS herein shown the connecting rod 52 includes a hollow tubular portion 65 which has a long cylindrical recess containing a long compression spring 66 and a long slender rod 67 inside said spring. The rod 67 is rigidly connected at one end to a reduced plunger portion 68 of the yoke 53 and has an enlarged head 69 at its opposite end that engages the spring 66 to compress the same when the yoke S3 is moved away from the tubular portion 65 which is connected to the lever 55. The tubular portion of the connecting rod is rigidly connected to an annular guide 70 which has an internal bore providing a cylinder for slidingly receiving and guiding the plunger portion 68. Movement of the lever 49 clockwise as viewed in Fig. 44 moves the enlarged portion of the yoke 53 against the end of the guide 70 and positively drives the connecting rod and the rack in a direction to retract the feed plate 32. Movement of the lever 49 in the opposite direction compresses the spring 66 between the head 69 and the end of the guide 70 and yieldingly advances the feed plate. The spring will be compressed to permit sliding of the yoke 53 with respect to the tubular portion 65 when the screw 61 engages the table 4.

As herein shown the feed plate 32 is adapted to feed Vflat sheet metal circular blanks 6 of a given size to the rst die 5. The blanks are guided to a position to be engaged by the feed plate by means of a magazine 71 having a plurality of upright guide rods 72. The magazine is held in upright position on the table 4 by an annular marginal flange 73 which is connected to the table on The flange is spaced from the portion of the table top over which the feed plate and the blanks slide a distance greater than the thickness of a blank and greater than the thickness of the feed plate as shown in Fig. 5 so that blanks may slide horizontally from beneath the magazine 71 toward the first die 5. However, this distance is preferably less than twice the height of a blank to prevent more than one blank from being fed from the stack at any one time.

The feed plate 32 has a thickness less than that of each circular blank 6 and when advanced by the rack 62 removes the blank at the bottom of the pile of blanks from the pile and advances it toward the die 5. The bottom portion of the magazine 71 prevents any other blanks in the stack from being advanced at this time. The stop 61 may be adjusted so that the feed plate 32 advances a blank a distance equal to or slightly greater than the diameter of the blank each time the flywheel 12 rotates one revolution. When the blanks reach the die 5 they may be guided into the proper position coaxial With the die. As herein shown a stop 14 is provided to halt each blank at the proper place before it is drawn into a cup, the position of a blank just before drawing thereof being shown in dotted lines in Figs. 2 and 5 coaxial with the die 5. If the normal stroke of the feed plate 32 is too great due to improper adjustment of the stop 61, the stop 14 will 9 prevent advancing of the blanks beyond the end of the die and will cause the spring 66 to compress so as to reduce the stroke of said feed plate.

The spring 66 not only permits adjusting the stroke of the feed plate but also avoids damage to the machine where the blanks jam during feeding or where a broken punch and/ or a drawn piece remains in the die 5 to prevent advancing of the feed plate.

The novel feeding mechanism of the present invention includes a cylindrical vcam wheel 74 that is keyed to the shaft 37 for rotation therewith. Opposite sides of the Wheel are provided with endless face grooves 75 and 76, each of uniform depth throughout its length. The grooves provide two non-circular guides of somewhat similar shape for receiving two cylindrical follower rollers 77 and 78 which, in the punching machine shown herein are substantially coaxial when the gripping iingers are in gripping position, the diameter of each follower being substantially equal to the width of its associated cam groove. The follower rollers are rotatably mounted on parallel stub shafts 79 and 80 which are carried by levers 81 and 82 for oscillation therewith. The levers are located adjacent opposite faces of the cam wheel 74 and are rigidly connected at their lower ends to a pair of coaxial pivot pins or shafts 83 and 84. Said pivot pins are journaled in a pair of bearing bosses 85 and 86 carried by the side walls 39 and 40 of the housing 38 and are mounted to oscillate with the levers 81 and 82 about an axis parallel to that of the shaft 37.

The levers 81 and 82 are operatively connected to cylindrical push rods 87 and 88, respectively, which are slidably mounted in the housing 38 to reciprocate horizontally along two xed parallel axes parallel to the rows of dies and punches. The rods are mounted to slide in guide blocks S9 and 90 carried by opposite end walls of the housing 38 and are provided with enlarged rectangular portions 91 and 92 intermediate the guide blocks. The enlarged portions of the rods have fiat vertical surfaces in sliding engagement and are slotted to receive the upper ends of the levers 81 and 82 and a pair of anti-friction rollers 93 and 94, the width of each slot being substantially the same as the thicknesses of the roller and the lever in said slot. The roller 93 is mounted in the portion 91 for rotation on a stub shaft 9S carried by said portion. The roller 94 is similarly mounted on a stub shaft 96 carried by the portion 92 for rotation about an axis parallel to the axes of the shafts 37 and 95. The upper ends of the levers 81 and 82 are provided with vertically elongated slots 97 and 98 of a size to receive the rollers 93 and 94. The slots preferably have a width substantially equal to the external diameter of said rollers so that lost motion between the push rods 87 and 88 and the levers 81 and 82 is less than about 0.001 inch when the rods are reciprocated due to rotation of the cam wheel 74.

The ends of the push rods are externally threaded and are received by internally threaded connecting blocks 99 and 100 of rectangular cross section. The blocks are slotted to receive dovetails 101 and 102 which are internally threaded to receive spaced pairs of transversely alined upright attaching bolts 103 and 104. The Shanks of the bolts 103 and the upper portion of the dovetail 101 are received by a separate rectangular block 105 whereas the shanks of the bolts 104 and the upper portion of the dovetail 102 are received by a transverse cross-bar 106.

The push rods S7 and 88 are rigidly connected to a gripper carriage 107 and an actuating frame member 108, respectively, to reciprocate the same in timed relation to the `operation of the punches. The gripping fingers 31 are moved into and out of a gripping position in response to relative movement between said carriage and said frame member and are likewise moved in timed relation to operation of the punches.

The gripper carriage and the frame member are mounted -on the frame 1 for sliding movements parallel to the rows of punches and dies. As herein shown, the table 4 l10 has upwardly projecting guide portions 109 and 110 which extend longitudinally and form with the upper surface of the table a groove or nay of rectangularV cross section for slidably receiving the frame member and the gripper carriage.

The frame member or actuating member 10S comprises a pair `of transversely-alined longitudinally-extending actuating bars 111 and 112 which are rigidly connected by a pair of cross-bars 106 and 113. The cross-bar 106 is rigidly connected to the connecting block and the push rod 08 by the dovetail 102 and the bolts 104 so that the frame member 108 reciprocates in unison with the push rod 88. The outer side faces of the bars 111 and 112 are parallel and slidably engage the inner faces of the guide portions 109 and 110, respectively. The bottoms of the bars are located in a horizontal plane and slide on the iiat upper surface of the table 4 in a direction parallel to the rows of punches and dies as guided by the portions 109 and 110.

The gripper carriage 107 includes a large fiat upper plate 114 which extends horizontally from one end of the guide portions 109 and 110 to the connecting block 99 at the opposite end of said guide portions. The plate extends between the portions 109 and 110 and has marginal portions which slide horizontally in longitudinal grooves or ways 115 and 116 of uniform depth and height formed in said portions. The plate has a narrow laterally elongated slot 117 of a width to receive the bolts 103 and is rigidly secured by said bolts to the connecting block 99 and the push rod 87 for reciprocation therewith.

Rearwardly of the guide portions 109 and 110 the table 4 has parallel guide portions 118 and 119 with longitudinal grooves similar to the ways 115 and 116 for slidably receiving marginal portions of the rack 62 to guide the same in a longitudinal direction parallel to the rows of punches and dies.

Six pairs of rigid gripping fingers 31 are carried by the carriage 107 between the stripper plate and the seven dies, and a longitudinally elongated slot 120 is provided in the upper plate 114 to permit reciprocation of the carriage without interfering with lowering of the punches into the dies. As herein shown, the slot has a width to expose the gripping iingers when they are advanced or fully retracted. The six -gripping fingers on each side of the slot are carried by a pair of superposed longitudinal members 121 and 122 which are rigidly connected by suitable bolts or the like. Each pair of these members is of substantially rectangular cross section, has flat bottom surfaces slidably engaging the flat upper surface of the table, and has liat outer surfaces slidably engaging one of the bars 111 and 112. The fiat bottom of the plate 114 engages the flat upper surfaces of the two members 121 and slidably engages the flat upper surfaces of the actuating bars 111 and 112 `of the frame member 108 to prevent movement of said members away from the table 4.

The pairs of superposed members have inner edges substantially flush with the sides of the slot 120 and are rigidly connected to the plate 114 for movement therewith in unison. As herein shown this rigid connection is effected by a plurality of equally spaced dowel-like pivot ins 123 which extend through circular openings in the plate 114 and in the superposed members 121 and 122.

In the device shown herein, the superposed members carry six .equally spaced pairs of laterally alined pistonlike gripper carriers 124 which are mounted for reciprocation on the gripper carriage 107 in a direction normal to the -direction in which the carriage is reciprocated. A frangible wire gripping linger 31 is detachably connected to each carrier 124 by a screw 125, the piston being bifurcated to receive the wire ends of the linger as is best shown in Fig. 9. The six equally spaced pairs of gripping fingers are automatically moved transversely in response to relative longitudinal movement between the actuating bars 111 and 112 and the gripper carriage 107. The fingers of each pair of grippers are alined laterally and are fmovable towards each .other to gripping position when ja 1piece .istodne `advanced from one dieto another.

LIt will be .understood that any suitable grippers may be employed in the punching machine and that articles of various shapes and sizes may be handled. As herein shown, the fingers are adapted to grip cup-shaped pieces of the .typeshownin Fig. 2, and each finger 31.is formed from `a single lpiece offrangible hardened steel wire and is bent so that the wireends are horizontal and-the intermediate .portion is U.shaped and upright. The legs of the U-shapedportion are vertical and provide article engaging surfacesgfor gripping the pieces formed by the punches. ,The top part ofY said U-shaped portion is bent inwardlyas best shown in Pigs. 8 and-9 toy provide clearance for the vround portion `of the .article'projecting between the articlegripping legs.

.The1carriersl24 and the ngers 31.are moved'into and out Yof .gripping positionby a plurality .of Ybell cranks or levers 126, each of which is mounted on one of the pivot pins 123 toconvert longitudinal movement of the frame member .108 on the carriage 107 into transverse movement of a carrier 124. The actuating bars 111 and 112 and the carriers 124 are provided with slots to receive opposite ends of the bell cranks, said ends being rounded substantially as shown in Fig. 13 to facilitate oscillation of the cranks. The width of the slot in each carrier 124 is preferably substantially the .same as the diameter of the rounded end of the bell crank Vreceived in said slot so as to eliminate lost motion between the bell crank and the carrier. However, the slots in .the bars 111 and 112 are preferably large enough vso that the slots do not prevent Voscillationof the bell cranks to their retracted positions. As herein shown, opposite end portions .of the bell cranks have a uniform thicknesssubstantially equal to the height of the slots in which they oscillate.

In order to yieldably resist movement of the bell cranks .and the grippers away from gripping position, the bars 111 and 112 are provided withcoaxial cylindrical bores for slidably receiving a .plurality of piston-like followers 127 :as best shown in Fig. 13. Each follower is held .against the rounded end .of a bell crank or lever 126 by a compressionspring 128. Theend of each bell crank is normally held against the upright wall of its slot by the spring and is normally moved by one of the actuating bars 111 and 112 into and out of gripping position. However, `the spring is .arranged to permit yielding of the gripping fingers radially when the article being gripped prevents movement of the ingers radially inwardly whereby crushing of the article or damage to the gripping fingers is avoided. The followers 127 and the follower springs 128 thcreforerprovide a resiliently yieldable connection between the frame member 108 and each of the gripping fingers 31.

According to the present invention the inertia and change of momentum of the grippers and the vgripper actuating mechanism are minimized so as to permit operation at extremely highspeed. The frame member 108 and the followers 127 carried thereby are of relatively light weight and have little inertia resisting linear acceleration. Similarly the bell cranks or levers are relatively light and have little'resistance to angular acceleration. The gripper carriers 124 and the gripping fingers 31 carried thereby are extremely light and have even less inertia than the frame member 108. In order to minimize the change in momentum when the grippers are actuated it is preferable to provide a speed multiplying connection between the frame Vmember and each gripping finger so that movement of the frame member is minimized. As herein shown the levers V126 provide speed multiplying connections between theframe member and the carriers 124. The pivot pins 123 are located -closei' to the ends of the levers 126 which engage the frame member than to the ends l-of the levers which engage the carriers '124 so thatthe-carriers andthe-grip- -ping fingers supported thereby move atleast 50% Vfarther withgrespect to ,the `gripper'carriage than. the-framemember.

Each carrier 124 is .accuratelyguidedinits .associated bore;and.rigidly. supports a gripping finger V31-so that the finger is ,accurately .positioned with respect to .the punches :and dies ywhen it moves .into .gripping posi tion. Each .gripping .finger .must be vsubstantially rigid and sufficiently strong to .accurately position .articles in .alinement with the punches and dies and yet must be frangible to prevent damage to .the .machine .whenexcesforces are appliedto thelingers. A rigidfinger is preferred since itmay be brittle .and since. it permits positioning of the article gripped within .a few thousandths of .aninch of thef desired location. In the machineshown herein the wire fingers 31 are rigid and .are vaccurately guided by the carriers 124 .and .the gripper carriage is accurately controlled so .that articles are positioned within two or .three thousandths of an inchoi the desired lo-cation'when the machine is in operation.

fn order to prevent .damage lto the machine the ngers 31 are preferably .formed of hard brittle steel which 1s sufficiently .durable when the machine is functioning Yproperly but which is frangible when subjected to excessive forces which might damage the gripper carriers, the gripper actuating mechanism, or the carriage actuating mechanism.

If the fingers grip a broken punch that is held against movement by the stripper plate 30 or by one of the dies, the fingers will break and cannot damage the machine by preventing reciprocation of the gripper carriage. lf a fingerdoes break, it can be readily removed by loosening a screw125 and replaced with another linger.

.The springs 123 cushionimpact ofthe .gripping fingers with the article being gripped and prevent damage to the frangible fingers due to engagement of the fingers with tilted or oversize pieces.

The gripper carriage 107 and the frame member 103 are moved to opposite. ends of their strokes substantially in unison and are accurately controlled by the cam wheel 74. .T he face grooves 75 and 76 may be cut or otherwise formed in opposite faces of the cam wheel but are preferably formed by replaceable cam members so that the shape of the grooves may be readily modified. In the event the length of stroke ofthe punches isxnodified by replacing the crankshaft 22, the type of punches and dies is modified, or other changes are made, the shape of the cam grooves and the timing of the feeding mechanism may be readily varied.

As herein shown the cam wheel 74 is provided with annular grooves or recesses and 136 in its opposite faces that are concentric to the shaft 37 and which receive innerand outer cam members-to form the inner and outer margins of the cam grooves 75 and 76. The radiallyouter portion of the recess 136 receives -a plurality of segments 137 to 140 which abut to provide an endless cam surface that forms the outer margin of the groove 76, and the inner portion of said recess receives a plurality of segments 141 to 144 that abut to provide an endless cam surface that forms the inner margin of said groove.

The radially inner and outer portions of the recess 13S likewise receive removable cam members 146 and 147 which form the outer and inner margins, respectively, of the groove 75. Both the cam segments 13'7 to Md and the cam members 146 and 147 `are drilled and threaded to receive the attaching bolts 145 and have fiat bottom surfaces and rounded outer surfaces which are held in engagement with the bottom and marginal-surfaces of the annular grooves or recesses 135 and 136. These cam members and cam segments therefore form withthe cam wheel 7 a rigid double faced cam for actuating both the gripper carriage 107 and the actuating frame member 108 in a longitudinal direction. The cam members form- The face grooves 75 and 76 formed on opposite sides of the cam wheel 74 have a width and depth throughout their length to receive the follower rollers 77 and '78 and are similarly contoured as best shown in Figs. ll and 12 so that the frame member moves substantially in unison with the gripper carriage when the gripper carriage is moved and moves substantially the same distance longitudinally as said carriage. The face groove 75 is smoothly curved throughout its length and reciprocates the gripper carriage without undue accelerations through a distance equal to the distance between the axes of adjacent punches or dies. Opposite end portions of the groove 75 are of circular form so that the gripper carriage dwells in a stationary position for a substantial period of time at each end of its stroke. The groove 76 is shaped to provide a similar reciprocation and a similar dwell for the frame member 108 but has sharply curved projecting shoulders for rapidly moving the frame member while the gripper carriage is stationary at each end of its stroke.

Operation of the cams will be apparent from Figs. l1 and 12. The cam segments 137 and 141 are radially alined and extend for about 180 to form half of the `cam groove 76. This half of the groove is identical with half of the groove 75 and is alined with said grooves so that the frame member moves in unison with the gripper carriage for about 180 of rotation of the cam wheel 74. The groove 75 is symmetrical and moves the gripper carriage from one end of its stroke to another in about 60 of rotation with a dwell of about 120 between actuations.

The abutting edges of the three segments 138, 139 and 140 are radially alined with those of the segments 142, 143 and 144, respectively, and each segment preferably extends from 50 to 60 around the cam groove 76. As herein shown the segments 138, 140, 142 and 144 are of substantially the same angular extent and the segments 139 and 143 extend through an angle of about 65 The latter segments are smoothly curved throughout their length and have substantially the same curvature as corresponding portions of the cam members 146 and 147 so that the frame member and the gripper carriage move substantially in unison from one end of their stroke to the other as the follower roller 78 is moved relative to the cam wheel from one end of the `cam segment 143 to the other.

As shown in Figs. l1 and 12, the symmetrical face groove 75 formed by the cam members 146 and 147, half of which may be exactly the same size as the groove formed by segments 137 and 141, has a width throughout its length substantially equal to the external diameter of its associated follower roller 77 so as to accurately control the position of the gripper carriage at all times. The portion of the face groove 76 formed by the cam segments 139 and 143 likewise has a width throughout its length substantially equal to the diameter of the follower roller 78 so as to accurately control the position of the frame member 108. In order to position the gripper carriage within .001 or .002 inch of the desired location at each end of its stroke, the gripper actuating mechanism including the elements 83, 76, 97, 146 and 147 are preferably very accurately machined. If desired, the actuating mechanism for the gripping lingers 31 may also be machined with extreme accuracy so that movements of the fingers transversely are controlled within a few thousandths of an inch.

lt will be apparent from Figs. 11 and 12 that the smoothly curved follower engaging surfaces of the cam segments 139 and 143 are parallel to and offset radially outwardly from the corresponding surfaces of the cam members 146 and 147 a predetermined distance equal to the length of stroke of the follower roller 77 and proportional to the stroke of the frame member S so that there is no relative movement between the frame member and the gripper carriage except while the follower roller engages the cam segment 140 or 142.

The major follower engaging portion of the cam seg- 14 ment 142 is circular and has the same curvature as the corresponding portion of the cam 147 with which it is alined so that the frame member may dwell with the gripper carriage in a stationary position at one end of its stroke, but said segment is provided with a raised portion or shoulder 148 adjacent one end of the segment 143 for rapidly actuating the frame member to cause moving of the gripping lingers out of gripping position. Also, the major follower engaging portion of the cam segment is circular and concentric to or parallel to the corresponding circular portion of the cam 146 with which it is alined so that the frame member may dwell with the gripper carriage at the opposite end of its stroke while the gripping lingers are released. The cam segment 140 has a raised portion or shoulder 149 adjacent the end of the cam segment 137 for rapidly moving the follower roller 7S to actuate the frame member 1118 and to advance the fingers 31 to gripping position.

The follower engaging surface of the cam segment B between the shoulder 149 and the segment 139 is concentric to the corresponding surface of the cam member 146 and tangent to the adjacent follower engaging surface of the segment 139 so that the actuating frame member 103 is not moved by the segment 140 until the follower roller 78 engages the shoulder 149. The position of the cam wheel 74 an instant before the follower roller '78 engages the shoulder 149 is shown in Fig. 12, the gripping fingers being fully retracted at this time and out of gripping position. When the cam wheel rotates counterclockwise from its position shown in Fig. 12, the frame member 108 and the gripping fingers are moved throughout the full length of their gripping stroke While the cam wheel rotates through a small angle until the follower roller 73 engages the cam segments 137 and 141.

The follower engaging surface of the cam segment 142 between the shoulder 14S and the cam segment 141 is circular and coaxial with the corresponding surface of the .cam member 147 with which it is alined and is tangent to the adjacent follower engaging surface of the segment 141 sothat the frame member 103 is not moved by the segment 142 until the follower roller 78 engages the shoulder 14S.

The curved follower engaging surfaces of the shoulders 143 and 149 are preferably very steep so that the gripping lingers release the articles and move out of the path of movement of the punches and articles substantially simultaneously with engagement of the punches with the articles and so that the gripping fingers move to gripping position substantially simultaneously with stripping of the articles from the punches by the stripper plate 30. Each of the shoulders is preferably formed to move the gripping iingers into or out of gripping position in a period of time less than about one-fortieth the time required for one revolution of the flywheel 12 or for one punching cycle. As herein shown, each of the shoulders 14S and 149 is at the end of its cam segment and extends circumferentially less than 10 around the margin of the cam groove 76 so as to move the follower roller 78 radially toward or away from a position in axial alinement with the roller 77 and to move the lingers 31 at high speed into or out of gripping position while the cam wheel 74 rotates through an angle of about 6 to 8. The lingers are therefore moved the full distance from one end of their stroke to the other while the flywheel 12 revolves through an angle of about 6 to 8 and while the gripper carriage dwells in stationary position at one end of its stroke.

By replacing the cam segments 140 and 142 with similar segments having shoulders located at various angular positions, the timing of the gripper actuations with respect to the operation of the punches may be closely controlled. The gripper lingers may be moved into or out of gripping position in the path of movement of the punches in any desired 6 to 8 of rotation while the follower roller engages the cam segments 140 .or 142, and the shoulders 14S and 149 may be in any desired position. If the speed of the punching operations is increased or decreased the angular extent and/ or slope of the shoulders may be varied accordingly.

As herein shown, the shoulder 148 is positioned to initiate movement of the fingers 31 out of gripping position when the advancing punches pass through the stripping plate 30 and begin to enter the cup-shaped articles, and the curved surface of the shoulder is steep enough to move the fingers out of the path of travel of the punches and the articles before the bottom faces of the punches engage the bottom portions of the cup-shaped articles. Similarly, the shoulder 149 is positioned to initiate movement of the gripping fingers ybefore articles are stripped from the punches so that the fingers are out of the path of travel of the punches and articles at the instant the articles engage the stripper plate 30 and are moved into gripping position in engagement with the articles substantially at the instant the punches leave the upper ends of the articles. Since the gripping fingers and the gripper actuating means are very light in weight, they ca'n move at extremely high speed and can grip the articles before said articles fall a substantial distance away from the stripper plate 30. The high speed gripping and releasing of the articles insures accurate positioning thereof in axial alinement with the punches each time the punches are lowered. A machine of the type shown can maintain accuracy of positioning within about .002 or .003 inch. This is usually sufficient for high speed operation since the noses of the punches serve as guides to correct any slight misalinement as the articles are moved into the dies. The ejector rods 130 and 131 also help to correct misalinement as the articles are advanced into the dies and to prevent misalinement as the articles are removed from the dies.

The stripper plate 30 likewise aids in positioning the articles so as to prevent tilting of'the articles before they are gripped by the fingers 31. The stripper plate is rigidly supported in a horizontal stationary position a predetermined distance above the dies greater than the height of the articles being formed by lateral bars 150 and 151 which are rigidly connected to the portions 169 and 110 of the table 4 beyond the ends of the row of dies. The bars form a rigid bridge for supporting the stripper plate in a predetermined position. The article engaging bottom surfaces of the stripper plate surrounding each punch receiving opening are flat and perpendicular to the axis of the punch so that the articles do not tilt as they are stripped from the punches and gripped by the fingers 31. When the gripping fingers are in gripping position as shown in Fig. 8, the at bottom surfaces of the stripper plate 30 are only a short distance above the top of the fingers so that there is little chance for tilting or misalinement of the articles being gripped.

The cam surfaces of the segments 138 and 144 are l l formed so as to permit the desired movement of the roller 78 by the shoulders 148 and 149 but need not e11- gage the follower roller for any substantial period of time while it is being controlled by the cam surfaces of the segments 140 and 142. The cam surface of the segment 138 adjacent the segment 139 is tangent to the cam surface of that segment, and the cam surface of the segment 144 adjacent the segment 141 is tangent to the cam surface of the latter segment.

As herein shown, the cam segment 138 is similar to the segment 140 and is provided adjacent the segment 137 with a sharply curved shoulder 150 similar to the shoulder 149. The cam surface of the segment 138 between the shoulder 150 and the segmentV 139 is circular and concentric to the corresponding surface of the cam member 146. Such a construction is preferred so that it is unnecessary to replace the segment 138 when the segment 142 is replaced with a segment having its shoulder 148 closer to the segment 141.

The cam segmentv 144 shown herein is similar to the r16 .segment .142v and is provided adjacent the segment 143 with a sharply Vcurved shoulder 151 similar to the shoulder 148. The cam surface of the ,segment 144 between the shoulder 151 and the segment 141 is circular Aand has the same curvature as the corresponding surface of the cam member 147 with which it is alined so that itis unnecessary to replace the segment 144 when the segment is replaced with asegrnent having its shoulder .149 closer to the segment 139.

With thecam segments shown in the drawing the-timing of the gripper actuations withrespect to operation ofthe punches is normally adjusted merely by replacing one `or both of the Acam .segments 140 and 142. If the height of the stripper Vplate above the dies, the speed of the machine, or other thngsare changed, the timing of the gripper actuations or the speed thereof may be readily changed by changing the angular position or shape of the shoulders 148`and 149.

The feeding mechanism of the present invention operates at high speed in accurately timed relation to the operation of the punches. In the punching machine shown herein, each cycle of operation is substantially as follows:

(l) When the flywheel 12 is at top dead center and the punches are fully retracted, the gripper carriage is in advanced position and the fingers 31 are in gripping position above the dies 6 to 11, each pair of fingers holding an article in axial alinement with a punch and die;

(2) The gripper carriage dwells in advanced position for about 120 degrees .of rotation of the flywheel 12 and the fingers 31 remain ,ingripping position;

(3) After the flywheel is moved almost 120 beyond top dead center to lower thepunches and just before the punches engage the articles gripped by the fingers 31, the follower roller engages theshoulder 148 to move the gripping fingers out of the pathof travel of the punches and articles, the fingers preferably being moved while the gripper carriage is stationary;

(4) As the fiywheel is rotated from about 120 beyond top dead center to about ,bottom dead center the gripper carriage is ,moved to'fully retracted position with the gripping fingers out of gripping ,position and above the dies 5 to 10;

(5) After the flywheel 12 is rotated to about 240 beyond top dead center and substantially simultaneously with stripping of articles from the punches by the stripper plate, the follower roller engages the shoulder 149 to move the fingers 31 to gripping position, the gripper carriage being stationary at this time;

(6) The gripper carriage dwells in its retracted position as the flywheel rotates from about to about 300 beyond top dead center; and

(7) As'the fiywheel 12 rotates about 60 lfrom about 300 beyond top dead center'to top dead center, the face groove 75 causes advancing movement of the gripper carriage to the position described in (l) whereby each article is advanced by a pair of gripping fingers 31 from a position in axial alinement with a punch and die to a position in axial alinement with an adjacent punch and die.

The above described cycle of operations is repeated for each revolution of the fiywheel 12, a circular blank being supplied to the die 5 each time the punches are retracted and each article formed from a blank being advanced automatically in timed relation tov operation of the punches so that a progressive `series of punching operations are performed on each article.

It is to be understood that in accordance With the provisions of the patent statutes, Variations and modifications of the specific devices herein shown ,and described may be made without departing from the spirit of the invention.

Having described my invention, I claim:

l. A punching machine having a'frame, a row of dies carried by the frame and having a row of equally spaced longitudinally aligned cavities, a punch holder mounted on said frame for movement vertically toward and away from said dies and carrying a row of aligned equally spaced punches movable into and out of said dies to perform a progressive series of forming operations on an article as it is advanced from die to die, means for driving said punch holder to reciprocate said holder and the punches carried thereby, a dat horizontal stripper plate carried by said frame having openings therein aligned with said punches, the margins of said openings providing means for separating each article from the punch and die acting thereon during retraction for the punches, reciprocating means for supporting a series of Hat circular blanks and for automatically feeding a single blank longitudinally forwardly to the die at one end of said row of dies each time the punches are retracted, means for limiting longitudinal forward movement of said blank beyond said die at said one end including a stop member mounted adjacent said die for engaging said blank as it moves to said die, means in said die cavities for engaging the articles formed in said dies from said blanks and for ejecting said articles from said die cavities as the punches are retracted, said stripper plate engaging the articles formed during each punching operation after the articles are lifted a predetermined distance above said dies and out of contact with said ejecting means, a gripper carriage on said frame, guide members engaging opposite sides of said carriage and permitting longitudinal movement of the carriage in a direction parallel to said rows of punches and die cavities While preventing movement of said carriage in all other directions, equally spaced pairs of rigid brittle gripping fingers mounted in rows on said carriage for movement thereon laterally into and out of an article-gripping position between said dies and said strippers, each of said pairs being adapted to engage opposite sides of an article to grip the same usbstantially as it is stripped from one of said punches and substantially until it is engaged by the neXt'adjacent punch, said gripping fingers being frangible and unable to prevent reciprocation of said carriage, a relatively light-weight actuating member carried by said frame and mounted for longitudinal reciprocation parallel to and in timed relation to movement of said carriage, a piston-like carrier rigidly connected to each of said gripping fingers and slidably mounted in a cylinder formed in said carriage for reciprocation in a transverse direction with respect to said carriage, means operably connecting said carriage to said punch holder and for reciprocating said carriage in timed relation to reciprocation of said punches to advance each pair of gripping fingers longitudinally to a first position in lateral alignment with one of the punches and thereafter to retract that pair of grippers longitudinally a distance equal to that between the dies to a second position in lateral alignment with the next adjacent punch with a dwell in said first and second positions, yieldable means responsive to relative movement between said gripper carriage and said light-weight actuating member for moving said carriers and the fingers carried thereby laterally toward and away from the articles above said dies including a series of bell crank levers pivotally mounted on said carriage and connected between said actuating members and said carriers, each bell crank lever having one lever arm for engaging one of said carriers so that the lever imparts a transverse movement to its associated carrier that is greater than the relative longitudinal movement between 18 said actuating member and said carriage to minimize the change of momentum of the moving parts of the machine, a spring being interposed between and end of each lever and said actuating member, actuating means for automatically moving said actuating member relative to said carriage while the carriage dwells at each end of its stroke including a rotary cam having a body and segments which may be removed from said body and replaced, said cam being shaped to move the carriers from Vone end of their stroke to the other while the carriage is stationary at each end of its stroke and while the cam rotates through an angle less than about 10 degrees so that the gripping fingers are moved into and out of their article-gripping positions at maximum speed, whereby the fingers grip the articles substantially simultaneously with stripping of the same from the punches and release the articles substantially simultaneously with engagement of the punches with the articles, said fingers providing the sole support for said articles during the intervals of time wherein said punches are out of engagement with the articles.

2. A machine as defined in claim 1 wherein the means for reciprocating said gripper carriage comprises a first rotary cam and a first follower engaging said cam and operably connected to said carriage to reciprocate the same longitudinally and wherein the cam for actuating said actuating member is la second rotary cam having a second follower operably connected to said actuating member to reciprocate the same longitudinally parallel to said carriage, said cams being similarly shaped so that the actuating member and the carriage move substantially in unison and having concentric portions of different diameter to provide a dwell at the end of the stroke of said carri-age, said first cam being smoothly curved throughout its periphery and said second -cam having small impact shoulders that impart hammer blows to said second follower and cause slight longitudinal movement of the actuating member relative to the carriage to move said fingers at high speed into and out of article-gripping positions while the carriage is at each end of its stroke, each of said impact shoulders having steeply inclined surfaces that extend less than l0 degrees around the cam.

3. A machine as defined in claim 1 wherein the punches and die `cavities are shaped to form from said blanks an annular article having a` radial ange, said punches having guide noses of reduced diameter for guiding the articles into the dies after they are released by said fingers and for holding the articles concentric to the dies as the articles are stripped from the punches and gripped by said fingers, said fingers moving a substantial distance laterally while the articles are unsupported so as to clear the radial anges of said articles in a minimum period of time.

References Cited in the tile of this patent UNITED STATES PATENTS 625,872 Carbone May 30, 1899 1,497,001 Rotherham lune 10, 1924 1,870,728 Hothersall Aug. 9, 1932 1,987,101 Fabrice Ian. 8, 1935 2,012,423 Ferris Aug. 27, 1935 2,180,265 Thiel Nov. 14, 1939 2,382,849 Bennett et al. Aug. 14, 1945

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