US2084456A - Bolster pin holder - Google Patents

Description

June 22,1937. F. J. RODE BOLSTER PIN HOLDER Filed Jan. 7, 1935 the press.

Patented June 22, 1937 UNITED STATES Are'r OFFICE 4 Claims.

My invention relates to a sheet metal drawing press and particularly relates to a holder for the bolster pins which are commonly mounted in the bolster plate of a sheet metal drawing press.

As is well known to those skilled in the art, a bolster plate is commonly mounted on the bed of a sheet metal drawing press and supports a male forming die which cooperates with a female die mounted on a reciprocating part or plunger of The female die acts inconjunction with a follower die slidably movable in coaxial relation to themale die and tends to grip the work. While the follower and female-dies hold the work, the female die draws it over the male forming die.

The follower die is commonly operated by I bolster pins which are insertable and freely reciprocable in openings formed in the bolster plate. The bolster pins are caused to reciprocate or are yieldingly held against movement during the operations of the cooperating female die by a pressure pad on which they bear and by means of which they are held upright in their respective openings. Oftimes during a retractory or nonworking stroke of the pressure pad, the bolster pins may dislodge themselves from their particular openings in'the bolster plate and fall from an upright position on to the pressure pad or into the base of the press, necessitating removal of the diesand bolster plate with its attendant delay and expense in order to retrieve the pins and reinsert the same in their respective openings.

My invention has for an object to provide 'means for holding the bolster pins in their remeans for holding the bolster pins in their respective openings, which functions independently of the bolster pin actuating means or pressure pad.

A still further object of the invention is to .provide a bolster pin holding means which enables yieldingly resistant movement of the bolster pins relative to the bolster plate thereby facilitating mounting or dismounting of the dies with reference to the bolster plate.

A more particular object is to provide an auxiliary pad supported by the main pressure pad and independently movable with respect thereto and forming means for yieldably supporting the bolster pins and dies operated thereby in a normal upwardly extending position. A still further common to all the pins and readily yieldable whereby the movement of one pin will cause a like movement of the others. -This feature-is of particular advantage when setting up the press.

The invention consists in other features and advantages which will appear from the following description and upon examination of the drawing. Structures containing the invention may partake of different forms and still embody the invention. To illustrate a practical application of the invention, I have selected a bolster pin holder as an example of the variousstructures and details thereof that contain the invention and shall describe the selected bolster pin holder hereinafter, it being understood that variationsmay be made without departing from p the spirit ofthe invention. The particular 'bolster pin holder selected is shown in the accompanying drawing and described hereinafter.

Fig. 1 of the accompanying drawing illustrates a broken front sectional view of a sheet metal press showing an embodiment of my invention in an installed position. Fig. '2 illustrates a 'view .of a section taken on the plane of the line 2--2 indicated in Fig. 1. Fig. 3 illustrates an enlarged View of a section taken" along the plane of the line 3-3 indicated in Fig. 2. a The sheet metal press shown in the drawing in part, for'purposes of illustration, has aframe I comprising a crown 2, a base 3, and uprights'4. The uprights 4 support the crown 2 above the base 3 and have suitable ways 5 in which is slidably supported a reciprocable plunger 6. 'I'he plunger 8 is caused to reciprocate by means of any well-known mechanical means, such as the drive shaft 8, powered as from some suitable source of 3 power in a manner well known to theart, The plunger 6 may carry a female .die member 9 shaped according to the work to be performed.

- The base 3 has a bed ID on which may be supported abolster plate I l. According to the 3 In operative relation to the with respect to the die member M. The ring die [5 has a surface, such as that shownat I6, facing the die member 9 which coacts with the die member 9 to grip the work and hold it while the die member 9 is being moved in mating relation to the die 14. The ring die is caused to move and regulated in its movement by means of suitable bolster pins I1 freely and slidablysupported in openings, I8 formed in the bolster plate.

The bolster pins "are caused to move and regulated in their movement by a pressure pad 20 located in the base 3 of the pressand reciprocated by any well-known means, such as the pneumatic bellows 2| which may be supplied from a suitable source of compression and be controlled by suitable valve mechanisms to expand and contract in a manner well known to those skilled in the art. It will be apparent that in a cycle of operation of the sheet metal press shown in Fig, 1, starting at the position shown in Fig. 1, the plunger 6 will be moved upwardly away from the bed l and at the same time the follower or ring die l5 may be caused to move upwardly, if desired, stripping the die M of the work, until the surface I6 of. the follower is flush with or slightly above, the head of the die member I4. A 7

piece of sheet metal is then placed on the surface l6 and the plunger 6 caused to move toward the bed I0 and the die l5, the die member 9 contacting the sheet metal. The follower die I5 is yieldingly held against movement by the bellows 2| acting through the'pressure pad and bolster pins 11 so as to effect a firm clamping; of the sheet metal between the die 9 and follower [5. Upon continued movement of the plunger 6, the sheet metal is formed about the die M, as shown at 23, the follower die l5 retreating in timed relation to the advancement of the die 9 in a manner well known to the art. 7

It will be seen that as long as the pressure pad 20 is controlled in its operation and amplitude of stroke, the bolster pins II will be maintained in their respective openings I8; However, as often happens, the source of pneumatic compression may fail causing the bellows to collapse or the operator may over amplify'the retracting stroke of the pressure pad a distance sufficient to permit the upper ends of the bolster pins to escape their respective openings and fall from an upright position on to the pressure pad 20 or into the baseof the press. In order to replace the fallen pins, it is necessary to stop the particular press, unmount the dies, and again reset the press. Considerable waste of time and expenditure of money is suffered by the user in the replacement of the bolster pins.

In order to prevent the movement of the ends of the bolster pins I 1 from their particular openings, Iprovidemeans independently movable with respect to the pressure pad 20 and tending to- 'yieldingly hold the pins upright in their respective opening. Preferably, such means comprises a plate or pin pad located in superimposed relation to'the pressure pad 20 and supported in position by a plurality of pins 26. The pins 2t extend through openings 21 formed in the pressure pad 20 and are slidably reciprocable with respect thereto. Each opening Z'Iis surrounded by a downwardly extending boss portion having an opening through which its particular associated pin 2,6 extends and may move. The lower .end of each pin 26 may be provided with a limiting stop pin 28. The boss is cored and forms a housing 32 and seat for a suitable compression 7 2,084,456 ,a ring die IS. The die I5 is steam movable spring 33 which bears against chamber wall and the pin pad 25. The springs 33 are preferably of a resiliency sufiicient to support the weight of the pin pad 25, the pins l1 and the particular follower die 15 in a fully uppermost position. Thus, it will be apparent that the length of the pins 26 operating through the pad 25 supplement the length of the bolster pins l1 and in so far as maintaining the pins IT in their respective openings, provide the effect, during unloaded; periods of the press, of a bolster pin substantially equal to the sum of the lengths of a bolster pin l1 and that part of the pin 26 which extends below the boss portion 3!]. This enables increased stroke of operation of the pressure pad 20 and if desired,

foreshortening of bolster pins commonly in use.

In dismounting or mounting dies on the bolster plate, the bolster pins may be easily and manually moved against the yieldable springs 33 to a position where the upper ends thereof are below the pper urface f t e h lst plate permitting the sliding of the dies over the bolster plate into a desired position of installation or dismantling. Also hen h ad .5 i moved a inst the ield ing pressure of the springs, all the bolster pins I! will follow requiring little further attention during setting or dismantling the dies. While in accordance with the provisions of the statutes I have illustrated and described one of the best forms of my invention nowknown to me,'those skilled in the art will readily appreci ate and understand that many changes may be made in the form and construction disclosed herein without departing from the spirit of the invention as set forth in the appended claims".

I claim: I 1. In a sheet metal press having a follower die, a bolster pin for actuating said die, a pressure pad for actuating said pin, and means for moving said pressure pad, a bolster pin holder comprising a. pin pad supported in superimposed re-" lation to the pressure pad and freely" movable with respect thereto, a plurality of springs disposed intermediate the pressure pad and the pin I pad, and a plurality of pins connected to the pin pad and extending through the pressure pad whereby the pin pad may be guided in its movements relative to the pressure pad.

2. In a sheet metal press having a reciprocable pressure pad, a bolster pin, a bolster pin holder comprising a movable pin pad for supporting the bolster pin and located in superimposed relation to the pressure pad, a yieldable means extending between the pressure pad and pin pad tending to maintain the pin pad in spaced rela tion to the pressure pad varying according to the movement of the pressure pad with reference to the press whereby the bolster pin is maintained stationary with reference to the press during certain of the reciprocable movements of-the pressure pad, and means engaging the pressure pad independent of the bolster pin for guiding the pin pad in its movements relative to said pressure pad whereby the pressure pad may engage thepin pad to transmit the force exerted bysaid pressure'pad during certain other reciprocal movements thereof to, cause movement of the pin pad and the bolster pin with reference a tion and along the axis of said pin, a bolster pin holder comprising means engageable by said pressure pad and adapted to engage the bolster pin in end abutting relation and readily disengageable therefrom, a resilient means tending to yieldingly resist engagement between the said pressure pad and said pin holder means and movement of the bolster pin toward the pressure pad with a pressure less than that exerted by means for reciprocating the pressure pad, and means engaging the pressure pad independent of the bolster pin for guiding the pin holder means in its movement relative to said pressure pad whereby the pressure pad may engage said pin holder means to transmit the force exerted by said pressure pad during certain reciprocable movements of said pressure pad to cause movement, with reference to the press, of said pin holder means and the bolster pin.

4. In combination with a sheet metal press having a working die, a bolster pin for actuating said die, a pressure pad for actuating said pin and means for moving said pressure pad, a bolster pin holder comprising a pin pad supported intermediate the pressure pad and the bolster pin and freely movable with respect to said pressure pad, a coiled spring disposed intermediate the pressure pad and the pin pad, and a pin disposed in concentric relation with respect to said spring engaging the pin pad and pressure pad so as to guide the movements of the pin pad relative to the pressure pad.

FREDRICH J. RODE.

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