US3213730A

US3213730A - Stagger blanking mechanism

Info

Publication number: US3213730A
Application number: US317014A
Authority: US
Inventors: Erwin B Byam
Original assignee: Textron Inc
Current assignee: Textron Inc
Priority date: 1963-10-17
Filing date: 1963-10-17
Publication date: 1965-10-26
Anticipated expiration: 1982-10-26

Description

3 Sheets-Sheet 1 Filed Oct. 17, 1963 INVENTOR EM Ma Degw ATTORNEYS Oct. 26, 1965 E. B. BYAM 3,213,730

STAGGER BLANKING MECHANISM Filed Oct. 17, 1963 3 Sheets-Sheet 2 INVENTOR EMMA) De w ATTORNEYS Oct. 26, 1965 E. B. BYAM 3,213,730

STAGGER BLANKING MECHANISM Filed Oct. 17, 1965 3 Sheets-Sheet 3 INVENTOR KM M pe w ATTORNEYS United States Patent ice 3,213,730 STAGGER BLANKTNG MEQHANISM Erwin B. Byam, Welcott, Conn, assignor to Textron Inc., Providence, 12.1., a corporation of Rhode Island Filed Oct. 17, 1963, Ser. No. 317,014 8 Claims. (Cl. 83-166) This invention relates generally to a blanking mechanism and, more particularly, to a blanking mechanism forming an integral part of a press for blanking workpieces from a strip of material while providing maximum utilization of the material.

Blanking, as it is known in the art, is the piercing of a workpiece from the material stock usually continuously supplied to the blanking mechanism. The blanked workpieces are then transferred to have additional operations performed on them. The size and shape of the workpiece to be blanked is dependent upon the article into which it will be formed. Very often, the workpiece is blanked in the form of a round, flat disc blanked from a wide strip of fiat material. From consideration of geometrical factors, it will be seen that, if a round disc is blanked from a continuous strip of metal with the discs being in alignment along the strip, substantial stock will remain on the strip. Since the strip with the workpieces blanked therefrom is reduced to scrap, it is quite clear that considerable waste is involved.

In order to reduce waste, it is known to stagger the blanked discs on a wider strip, thereby reducing the amount of scrap per disc. This can be accomplished in a number of ways. Firstly, the blanking die could be provided with two die cavities and two punches so that two staggered discs are concurrently blanked from the strip. However, the additional cost for the second punch and die makes this procedure economically undesirable. A second alternative would be to shift the strip laterally between consecutive blanking operations to stagger the discs or blanks. The major shortcomings of this system are the problems created in shifting a bulky roll of strip material. The third solution would be to laterally shift the punch and die on consecutive blanking operations so as to stagger the blanks without the necessity of shifting the roll of strip. This last-mentioned system has proven to be the most desirable.

Accordingly, it is an object of this invention to provide an improved mechanism for staggering workpieces blanked from continuous strip.

Another object of this invention is to provide an improved stagger blanking mechanism integral with a press which performs subsequent operations on the blanked workpieces.

A further object of the invention is to provide an improved stagger blanking mechanism integral with a press having simplified means for transferring the blanked workpieces to the next operating station of the press.

A still further object of the invention is to provide improved means for laterally shifting a punch and die on consecutive strokes of a press for staggering the workpieces blanked from a strip of material.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Generally speaking, in accordance with the invention, a press such as a multi-plunger press carries a punch and die shitfable along a line parallel to the line of transfer between consecutive stations of the press. Additionally, the punch is adapted to be reciprocated toward and from the die by means of one of the plungers of the multiplunger press. The punch and die are shifted through a plurality of linkages driven in timed relation with the reciprocation of the punch with the linkages being inter- 3,213,730 Patented Oct. 26, 1965.

connected in such a manner that the location and stroke of the shifting punch and die set may readily be adjusted. In synchronism with the blanking operation, yieldable means operate to transfer a blanked workpiece to the next operating station. The yieldable means minimize the possibility of damage to the machine in the event that one of the workpieces being transferred becomes jammed in the mechanism.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a partial side elevational view of a machine constructed in accordance with the invention;

FIG. 2 is a partial front elevational view, partly in section, of a machine constructed in accordance with the invention;

FIG. 3 is a partial sectional view taken along line 33 of FIG. 2;

FIG. 4 is a partial sectional View taken along line 44 of FIG. 2; and

FIG. 5 is a partial sectional view taken along line 5-5 of FIG. 1.

Before commencing with a detailed description of the drawings, it should be noted that the mechanism embodying the invention herein is shown as being incorporated in a multi-plunger press wherein each of the plungers are separately actuated from a single driveshaft. As is known in the art, the plungers may be operated through cams or pitmans and the mode of operation of the plungers does not in any way affect the instant invention. Furthermore, the instant invention is equally adaptable for use in headers and like mechanisms wherein all the punches are normally mounted to and operated by a single gate. Thus, the disclosure of the mechanism forming the invention herein in conjunction with a multiplunger press, is not to be considered as a limitation here- Referring now to FIGS. 1 and 2, journalled in the machine frame 11 is a driveshaft 12 drivingly connected to a shaft 13 through bevelled gears 14. Shaft 13 is also journalled for rotation in the machine frame. The machine frame carries a die bed 15 on which is slidably mounted a carrier 16 formed of a lower half 17 and an upper half 18. The lower half of the carrier is slidably mounted to die bed 15 and carries a die 19. Lower half 17 slidably engages a pair of guides 21 (FIG. 3) which guide it for sliding movement toward the left and right as viewed in FIGS. 2 and 3. Upper half 18 is rigidly secured to lower half 17 for movement therewith. Upper half 18 is provided with a wide arm portion 22 which is also guided for sliding movement in the machine frame by means of a pair of guides 23 also secured to the frame. Upper half 18 carries a bearing 24 which slidably receives a punch 25. Punch 25 is adapted to cooperate with die 19 for blanking a workpiece on reciprocation of the punch. Since both the punch and die are carried by carrier 16, their relative positions will be unaffected by the sliding movement of the carrier in the machine frame.

A plunger 26 of the multi-plunger press is positioned above punch 25 and is adapted to reciprocate the punch in the direction shown by the arrow in FIG. 2. The plunger, of course, does not move laterally with the shiftable carrier and means are therefore provided to permit relative lateral movement between punch 25 and the plunger while securing the punch to the plunger for the purpose of reciprocating the punch. Referring especially to FIGS. 2 and 4, plunger 26, which is slidably mounted in machine frame 11, is provided, in its lower face thereof, with a wide elongated slot 27 and a narrow elongated slot 28. A pair of blocks 29 are secured in the wide elongated slot and form a dovetail groove which cooperates with a dovetail tongue 30 on the uppermost portion of unch 25. Through the dovetail arrangement, the punch is free to move laterally with respect to the plunger 'but is secured to the plunger for up and down movement. A pin 31 is slidably mounted within the punch along the central axis thereof and is urged outwardly or toward die 19 by means of a spring 32. The use of which pin will be hereafter described.

Referring again to FIGS. 1 through 3, a bell crank 33 is pivoted to the machine frame intermediate its ends and a link 34 is pivotably connected between one end of the bell crank and arm portion 22. It will immediately be seen that rocking or arcuate movement of ball crank 33 will effect reciprocation of carrier 16 through link 34. A block 35 is pivoted to the other end of hell crank 33 and threadedly receives one end of an adjusting bolt 36. The other end of the adjusting bolt is threadedly received in a block 37 which is adjustably connected to an arm 38. The position of block 37 along the longitudinal axis of arm 38 may be adjusted by means of a bolt 39.

Arm 38 is secured at its innner end fast on a shaft 41 which is rotatably journalled in the machine frame. Also mounted fast on shaft 41, spaced from arm 38, is a bifurcated bell crank 42 having a first arm 43 and a second arm 44. First arm 43 carries a cam follower 45 engaging the surface of a cam 46 which is mounted on and rotates with shaft 13. Second arm 44 carries a cam follower 47 which engages and rides on the surface of a cam 48 also mounted fast on shaft 13 for rotation therewith. The

cam followers

45 and 47 are disposed on opposite sides of

cams

46 and 48 with respect to the center of the cam pivots. In this manner, cam 46 positively rotates bell crank 42 .in a clockwise direction (as seen in FIG. 3) on shaft 41 while cam 48 positively rotates bell crank 42 in a counterclockwise direction. Through arm 38 and bell crank 33, positive reciprocation of carrier 16 is provided for.

With any preselected profile of

cams

46 and 48, control may be had over both the stroke of carrier 16 and the position of the carrier at its shifted positions. The position of the carrier is controlled by suitable adjustment of adjusting bolt 36 wherein the lengthening of distance between

blocks

35 and 37 will position the carrier more toward the right as viewed in FIG. 3 and the shortening of the distance between the blocks will move the carrier more toward the left. By suitable adjustment of bolt 39, block 37 may be moved closer or further from the center of shaft 41. By increasing the distance, the length of the are through which block 37 is moved on any particular degree of arcuate travel of arm 38 is increased, thereby increasing the stroke or the distance of shifting of carrier 16. Reverse adjustment conversely decreases the stroke.

The material from which the workpieces or discs are blanked is usually supplied to the blanking station from a large roll mounted adjacent the front of the machine with a take-up reel being provided adjacent the rear of the machine. The strip, indicated at 49, is fed past the blanking station in the direction indicated by the arrow in FIG. 3 and is guided between rolls 51. Since the means for feeding the strip form no part of the invention herein, no description thereof is deemed necessary. It must, however, be noted that the strip is fed intermittently so that the strip is not moving at the time during which the disc is being blanked from the strip.

The strip passes between the punch and die and a disc is blanked from the strip on each reciprocation of plunger 26. As seen in FIG. 3, the rate of strip feed is synchronized with the reciprocation of the plunger and the shifting of the punch and die to provide maximum utilization of the strip material, thereby minimizing waste. Plunger 26 is reciprocated by means (not shown) which also drive 4

shafts

12 and 13. The profile of

cams

46 and 48 and the speed of shaft 13 is so selected that the punch and die is shifted after each reciprocation of the plunger.

Referring more specifically to FIGS. 1, 2 and 5, strip 49 is fed into the blanking station along the surface of die 19. Upon reciprocation of plunger 26, punch 25 blanks a disc 52 from the strip and carries it through the die to the surface of die bed 15. This is clearly shown in FIG. 2. As the plunger and punch recede, pin 31 extends beyond the surface of the punch under the force of spring 32 to assure that the disc does not adhere to the face of the punch. A pusher blade 53 is slidably mounted along the face of die bed 15 and is adapted to be advanced to the left as shown in FIG. 2 to clear the blanked disc 52 to the next operating station of the machine where forming operations will then be performed. Thereafter, the usual transfer mechanisms in machines of this general type will carry the workpiece between subsequent stations. The mechanism for operating pusher blade 53 will now be described.

A slide 54 is slidably dovetailed in the machine frame as shown in FIG. 1 and pusher blade 53 is secured thereto. An arm 55 is secured to slide 54 and one end of a link 56 is pivoted to arm 55. The other end of link 56 is mounted fast on a shaft 57 rotatably mounted in the machine frame. One end of second link 58 is also mounted fast on shaft 57 for rotation therewith and the other end of link 58 carries a cam follower 59. Cam follower 59 engages the surface of a cam 61 which is secured to shaft 13. A pair of springs 62 act between arm 55 and the machine frame, urging slide 54 to the left as shown in FIG. 2. Springs 62 yieldably urge shaft 57 in a counterclockwise direction thereby holding cam follower 59 against the surface of cam 61.

After a disc has been blanked from the stock and punch 25 commences to recede, the rotation of shaft 13 brings the low side of cam 61 below cam follower 59, thereby permitting link 58 to rotate in a counterclockwise direction under the tension of springs 62. The counterclockwise movement, through link 56, moves slide 54 and pusher blade 53 to the left (FIG. 2) and clears disc 52 to the next operating station. After the disc is cleared, cam follower 59 will approach the high side of cam 61 thereby causing clockwise rotation of shaft 57 and withdrawing the pusher blade to the right to move it to a non-interfering position. It will also be noted that, at the same time, the punch and die will be shifted to its alternate position prior to advance of the plunger for the next blanking operation. The clearing movement of pusher blade 53 takes place by means of the tension of springs 62 rather than under the positive drive of cam 61. By this means, damage to the pusher blade will be avoided if the disc should become jammed.

In some blanking operations, such as where the disc to be blanked has a diameter approaching the width of the strip, it may be desirable to render the punch and die shifting mechanism inoperative and lock it in a central position. In such case, a boss 63 (FIG. 2) is provided on the machine frame. Arm portion 22 is disconnected from link 34 and a pin is secured through the pivot of arm portion 22 into a suitable aperture 64 in boss 63. Link 34 will also be disconnected from bell crank 33 so long as carrier 16 and the punch and die are to be held stationary. Note that during the stationary operation, bell crank 33 Will continue to be operated through

cams

46 and 48 but the operation will be ineffective. However, during the stationary operation, the operation of pusher blade 53 is in no Way affected and the pusher blade will continue to clear the blanked discs to the next machine station.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. In a machine of the class described having a frame, a die bed, a member reciprocated toward and from the die bed, and drive means for reciprocating said member, the combination comprising a carrier slidably mounted on the die bed, a die mounted in said carrier, a punch slidably mounted in said carrier, means slidably mounting said punch to the reciprocated member, and means driven by the driven means for slidably shifting said carrier in timed relation to the reciprocation of the member.

2. The structure defined in claim 1 wherein said lastnamed means comprises a cam driven through the drive means, a crank pivoted to the machine frame and cooperatively engaging said cam, and a link connected between said carrier and said crank for reciprocating said carrier in response to the rocking movement of said crank.

3. The structure defined in claim 1 wherein said lastnamed means comprises a pair of cams driven through said drive means, a crank pivoted to the machine frame and provided with follower portions engaging the surface of each cam, a second crank pivoted to the machine frame, adjustable means interconnecting said first and second cranks, and a link acting between said second crank and said carrier.

4. The structure defined in claim 3 wherein said adjustable means comprises a first link pivoted at one end to said second crank, an adjustable threaded member threadedly engaging the other end of said first link, a second link threadedly receiving the other end of said threaded member, said second link being connected to said first crank, and means for adjusting said second link toward and from the pivot of said first crank.

5. In a machine of the class described having a frame, a die bed, a member reciprocated toward and from the die bed, and drive means for reciprocating said member, the combination comprising a carrier slidably mounted on the die bed, a die mounted in said carrier, a punch slidably mounted in said carrier, means slidably mounting said punch to the reciprocated member, and camoperated means driven by the drive means for slidably shifting said carrier in timed relation to the reciprocation of the member.

6. In a machine of the class described having a frame, a die bed, a member reciprocated toward and from the die bed, and drive means for reciprocating said member, the combination comprising a carrier slidably mounted on the die bed and having at least a portion thereof spaced from said die bed, a die mounted in said carrier in spaced relation with said die bed, a punch slidably mounted in said carrier, means slidably mounting said punchto the reciprocated member, means driven by the drive means for slidably shifting said carrier in timed relation to the reciprocation of the member, and pusher means slidably positioned between said die bed and said carrier and reciprocated toward and from said die after each advancement of said puch within said die.

7. The structure defined in claim 6 wherein said pusher means comprises a blade slidably mounted on said die bed, a blade carrier slidably mounted in the machine frame for movement along a single axis, said blade being attached to said blade carrier, a crank pivoted intermediate its ends to the machine frame, said crank being pivoted at one end to said blade carrier, a cam driven by the drive means, said cam cooperatively engaging the other end of said crank, and spring-biased means acting between the machine frame and the blade carrier for urging said blade carrier toward said die.

8. In a machine of the class described having a frame, a die bed, a member reciprocated toward and from the die bed, and drive means for reciprocating said member, the combination comprising a carrier slidably mounted on the die bed, a die mounted in said carrier, a punch slidably mounted in said carrier, means slidably mounting said punch to the reciprocated member, a shaft journalled in the machine frame and driven through the drive means, a plurality of cams mounted fast on said shaft, a crank assembly acting between at least one of said cams and said carrier for shifting said carrier in timed relation to the reciprocation of the member, a pusher blade slidably mounted in the machine frame for advancement between said die and the die bed, springbiased means urging said pusher blade toward said die, and a crank operated by another of said cams for withdrawing said pusher blade from the position proximate to the die.

No references cited.

ANDREW R. JUHASZ, Primary Examiner.

Claims

6. IN A MACHINE OF THE CLASS DESCRIBED HAVING A FRAME, A DIE BED, A MEMBER RECIPROCATED TOWARD AND FROM THE DIE BED, AND DRIVE MEANS FOR RECIPROCATING SAID MEMBER, THE COMBINATION COMPRISING A CARRIER SLIDABLY MOUNTED ON THE DIE BED AND HAVING AT LEAST A PORTION THEREOF SPACED FROM SAID DIE BED, A DIE MOUNTED IN SAID CARRIER IN SPACED RELATION WITH SAID DIE BED, A PUNCH SLIDABLY MOUNTED IN SAID CARRIER, MEANS SLIDABLY MOUNTING SAID PUNCH TO THE RECIPROCATED MEMBER, MEANS DRIVEN BY THE DRIVE MEANS FOR SLIDABLY SHIFTING SAID CARRIER IN TIMED RELATION TO THE RECIPROCATION OF THE MEMBER, AND PUSHER MEANS SLIDABLY POSITIONED BETWEEN SAID DIE BED AND SAID