Punch press die holder with hand-operated retaining clamp
A punch press die holder assembly includes a die holder body with a fixed rim which partially surrounds an upwardly opening die receptacle within the die holder. The receptacle is dimensioned to receive a punch press die, especially of any various circular dies now in commercial use. Cooperating with the fixed rim portion of the die holder is a moveable clamp member that is a portion of the rim that has a centrally directed surface which contacts the die when the die is in place within the receptacle. A manually operable fastener is operatively connected to the moveable clamp member to hold the clamp member in a closed position for restricting the movement of the die and the fastener is movable by hand to an open position for releasing the clamp member and the die from the die holder so that the die can then be removed and replaced from one side by sliding it horizontally out of the die holder.
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Applicants hereby claim the benefit of corresponding provisional application Ser. No. 60/932,420, filed May 30, 2007 which is incorporated herein in its entirety.
FIELD OF THE INVENTIONThis invention relates to the punch and die art and more particularly to an improved die holder for a punch press.
BACKGROUND OF THE INVENTIONIn the punch and die art and particularly in the field of high-speed automated forming and punching equipment for punching and forming a workpiece, e.g., sheet metal and especially in the case of automated turret punch presses, the punch presses are operated by computer to rapidly perform a series of punching or forming operations sequentially. These punch presses which by themselves form no part of the present invention are typically provided with aligned upper and lower turrets that rotate and are indexed intermittently between punching operations. The turrets may hold as many as a dozen or more separate punches that are used in sequence for performing given punching or forming operations.
In prior punch press die holders, the die is simply placed into a bored opening within the die holder and held in place by means of bolts, screws, or similar fasteners. Consequently, the placement and removal of a die requires the use of hand tools and is therefore labor intensive and time consuming. Although methods have been proposed to facilitate more rapid removal of noncircular dies, i.e. those that are octagonal, rectangular, etc., these methods are not applicable to circular dies. Thus, there has been no way to manually remove or replace circular dies that are in wide scale commercial use, that is to say without the use of hand tools. In addition, the die must be inserted or removed from the side since the top of the die holder is obstructed by the upper turret. It has been calculated that in the course of a day, a typical punch press operator may spend as much as two hours removing and replacing dies, and of course the press is out of production during this period.
In view of these and other shortcomings of the prior art, it is one object of the present invention to provide a way of reliably securing a circular punch press die within a die holder that allows removal and replacement of the die without the use of hand tools.
Another object of the invention is to provide a hand-operated retainer that is capable of enabling a circular holder die to be opened or closed manually with what can be referred to as a flick of the wrist and to make it possible for a die to be removed and replaced from the side of the die holder.
Another object is to provide a reliable hand-operated die retainer that will not accidentally release the die or allow it to slide upwardly out of its holder once locked in place manually.
Yet another object of the invention is to provide a manually operable die-retaining device that can be retrofitted into a variety of existing punch press tooling units including what is known as “thick turret” tooling as well as other tooling that employs circular dies.
Still another object is to provide a manually operable die holder that provides precision positioning, centering and angular orientation of each die, yet allows the die to be rapidly removed or replaced from the side of the die holder by means of simple hand movements.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following Figs. and detailed description which illustrate by way of example but a few of the various forms of the invention within the scope of the appended claims.
The invention provides a die holder assembly for a punch press that includes an annular die holder body with a circular rim which surrounds a die receptacle or socket within the die holder body. The receptacle is dimensioned to receive a punch press die, especially of any various circular dies now in wide scale commercial use. At the bottom of the receptacle is a die-supporting surface for limiting the downward movement of the die during operation. A moveable clamp member is provided as a part of the die holder. The clamp member has a centrally directed circular clamping surface which is constructed to forcefully engage the die when the die is in place within the receptacle. A manually moveable fastener is operatively connected to the clamp member to hold the clamp member in a closed position so as to prevent movement of the die but is able to be moved by hand to an open position for releasing the clamp member so that it can be removed bodily or swung to one side to permit lateral removal of the die from the die holder. In a preferred form, the clamp member is an arcuate element which comprises a segment of the rim of the die holder that surrounds the die. The clamp member preferably comprises a segment of a circle having the same inside diameter as the outside of the die. The ends of the clamp member are each connected to an adjoining portion of the rim. A connection at one end of the clamp member comprises the manually operable fastener. The other connection comprises a pivot or an easily separated connection such as a hook and socket connection between the end of the clamp member and an adjacent portion of the rim. In one form, the clamp member is provided with a hook, e.g. at its left end, that is engaged in a complementary shaped socket provided in an adjacent fixed portion of the die holder. A preferred fastener comprises a manually movable cam member at one end of a locking handle connected between the opposite end of the clamp and the die holder for forcefully moving the clamp to a closed position for holding the die in place when the cam is moved manually to a locking position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTSRefer now to the Figs., and particularly to
The clamp member 22 is in one form shown in
The clamp fastener assembly 24 includes a tension element, e.g. a cap screw 32, or other elongated fastener which extends through a slot 15a (
During use, the cam 38 can be positioned manually by an extension comprising an integral locking handle 38a which, as shown in
The axis 38d of the cam lobe, i.e. the high point 39 of the cam 38 (
To assemble the clamp fastener assembly 24, the screw 32 which has an adjustment nut 46 near the head is passed through the bore 22d of the clamp 22, is then threaded into the swivel 36 and is preferably bonded therein, e.g. with Loctite®. The swivel 36 is then placed between the bifurcated ends 38b, 38c of the cam and pins 40 and 42 are inserted. The screw 32 is placed in slot 15a and the adjustment nut 46 is then tightened against the bearing surface 15c of the clamp hook 14c to be almost tight when the locking handle 38a is in and “open” dotted line position of
Refer now to
At the left end of the handle 38a is provided a vertical pivot pin 41 that extends through an enlarged head 116 of an eyebolt 118. Threaded on the free end of the eyebolt 118 is a contoured nut 120 for holding the clamp member 22 in a closed die locking position when eyebolt 118 is placed within the slot 15a of the clamp hook 14c. Nut 120 should be turned to adjust the clamping force of handle 38a to about 25 lbs. Located approximately below the center of the clamp 22 is a finger slot 122 that is cut into the body of the die holder. As can be seen, the finger slot 122 opens upwardly as well as horizontally toward the position taken by the operator for enabling the operator's finger to be inserted beneath the die 18 when the die is to be removed. Connected by means of a clamp adjustment screw 129 to the left end of rim 14 is a moveable clamp adjustment base 131 which allows the clamp 22 to be moved to the left or right, i.e. toward or away from the left end of the rim 14 by turning the clamp adjustment screw 129. It will also be noted that the clamp member 22 is in this case provided with a clamp link 124 which is connected to the clamp 22 by means of a pivot pin 126 and to the clamp adjustment base 131 by means of a second pivot pin 128.
When a die 18 is to be to removed, the die clamp arm extension 100 is swung outwardly to a releasing position (
To close the clamp 22 after the die 18 has been inserted, the clamp is moved to the position shown in
The invention is rugged in construction, reliable in operation, and will securely hold circular dies 18 in the die holder but yet can be opened quickly with a flick of the wrist using no tools by manually pivoting the free end of the locking handle 38a outwardly to remove tension on screw 32 or bolt 118 thereby relieving the compressive force applied by the clamp member 22 against the adjoining wall of the die 18. When the clamp 22 is swung away from body 12 of the die holder, the die 18 can be easily withdrawn and replaced from one side whenever required. The handle extension 100 makes possible two important results at the same time; it acts as a lock when the pin 102 enters the recess 112 and the ease of opening and closing the die holder is substantially improved since the extension 100 is provided a greater moment arm. It was also found that the finger hole enables the die to be readily grasped for easy removal by the operator.
The directions; up, down, horizontal, left, right, etc. herein are used in a relative sense without limiting the spatial orientation of the die holder.
Many variations of the present-invention within the scope of the appended claims will be apparent to those skilled in the art once the principles described herein are understood.
Claims
1. A punch press die holder assembly comprising,
- an annular die holder body with a rim that extends around a portion of a die receptacle, the die receptacle being dimensioned to receive a punch press die therein,
- said die holder assembly having a die support for limiting the downward movement of the die therein,
- a moveable retaining clamp member as a part of the die holder that has a centrally directed surface which is positioned to contact the die and
- a manually moveable fastener assembly operatively connected to the clamp member to place the clamp member in a closed position that restricts the movement of the die and
- the fastener assembly is adapted to be repositioned by hand to an open position for releasing the die from the die holder.
2. The punch press die holder of claim 1 wherein the clamp member comprises a moveable segment of the rim of the die holder that contacts one side of the die.
3. The apparatus of claim 1 wherein the clamp member has a pair of ends with connections to adjacent fixed portions of the rim at each such end thereof and the manually moveable fastener is operatively associated with a first one of said connections.
4. The apparatus of claim 3 wherein a second one of said connections is a hook and socket connection between the clamp member and a portion of said rim adjacent thereto.
5. The apparatus of claim 1 wherein the fastener assembly comprising a manually moveable cam member that is operatively associated between one end of the clamp and the die holder for forcing the clamp into engagement with the die when the cam is moved manually to a locking position.
6. A punch press die holder assembly comprising,
- a die holder body with a rim partially surrounding a die receptacle therein, the receptacle being dimensioned to receive a punch press die therein,
- said die holder assembly having a die-supporting element for limiting the downward movement of the die therein,
- a clamp member as a part of the die holder that has a surface which is constructed to contact the die but is movable to provide an opening for access to the die from one side thereof,
- a fastener assembly operatively connected to the clamp member to move the clamp member to a closed position for preventing removal of the die,
- the fastener assembly comprises a manually moveable cam member that is engaged between the clamp and the die holder for forcing the clamp to a position for holding the die in place when the cam is moved manually to a locked position and
- the cam has a handle that is moveable by hand to an open position for releasing the clamp member and the die from the die holder.
7. The punch press die holder of claim 6 wherein the clamp member comprises a moveable segment of the rim of the die holder.
8. The apparatus of claim 6 wherein the rim has a pair of ends and the fastener assembly is connected to one of said ends.
9. The apparatus of claim 8 wherein a hook and socket connection is provided between the clamp member and a second one of said ends for enabling the clamp member to be removed bodily from the die holder.
10. A punch press die holder assembly comprising,
- a die holder body with a rim and a die receptacle therein, the receptacle being dimensioned to receive a punch press die therein,
- a moveable clamp member as a part of the receptacle that has a centrally directed surface which is constructed and arranged to contact the die when the die is in the die receptacle,
- a manually moveable fastener operatively connected to the clamp member to hold the clamp member in a closed position that prevents removal of the die and the fastener is moveable by hand to an open position for releasing the die from the die holder,
- the clamp member has a pair of ends and the fastener is connected to one of said ends, and
- a second one of said ends is pivotally associated with the die holder.
11. A die holder for a punch press comprising a die holder body that is divided into two cooperating moveably related die holding portions confronting one another,
- each of the die holding portions of the die holder has a centrally facing surface constructed and arranged to contact a mating outer surface of a die,
- at least one of the die holding portions is a clamp that is moveably mounted on the die holder with a pivotal connection at one end thereof for enabling the clamp to pivot with respect to the other die holding portion,
- a manually operable fastener that has a locking handle for being grasped by an operator for forcing an end of the moveable clamp member that is opposite the pivotal connection toward a locking position so as to exert pressure on the die for retaining the die in place within the die holder.
12. The apparatus of claim 11 wherein the locking handle has a cam member thereon with a lobe that is operatively associated with the die holder for tightening the clamp member when the lever arm is moved to a locking position.
13. The punch press die holder of claim 11 wherein the clamp member comprises a removable arcuate segment of the rim of the die holder.
14. The apparatus of claim 11 wherein the clamp member has a pair of ends, each with a connection to a portion of the die holder, the manually operable fastener comprises one of said connections and the other of said connections comprises a hook and socket or pivotal connection between one end of the clamp member and a portion of the die holder adjacent thereto.
15. The punch press die holder of claim 1 wherein the manually moveable fastener assembly comprises a locking handle and a handle extension is pivotally connected to the locking handle by a pivot pin.
16. The punch press die holder of claim 15 wherein the die holder has a retaining slot for the pivot pin to retain the clamp member in a closed position.
17. The punch press die holder of claim 1 wherein the clamp fastener assembly has an eyebolt connected to a free end thereof with a clamping nut threaded on one end thereof for engagement with a clamp hook located on said die holder body.
18. The punch press die holder of claim 15 wherein the clamp member has a clamp link pivotally connected between a proximal end thereof and a rim of the die holder body.
19. The punch press die holder of claim 18 wherein a moveable clamp adjustment base is adjustably connected between the link and the rim of the die holder.
20. The die holder of claim 1 wherein the die support is provided with a finger slot to facilitate manual removal of the die from the die holder.
21. The die holder of claim 1 wherein the die holder has a finger slot in a die supporting surface that opens outwardly in a horizontal direction and opens upwardly to expose a lower surface of a die.
22. A die holder for a punch press comprising, a die holder body having a socket for supporting a die therein, a clamp member proximate the socket for engaging and holding the die in the socket, a manually moveable arm member mounted upon the die holder and being operatively associated with the clamp member for moving the clamp member into a die-retaining position when the arm member is moved manually to an operating position and said arm member releasing the die when the arm member is moved manually away from the operating position such that the clamp member is then moveable away from the die-retaining position to provide an opening for access to the die at one side thereof for removing the die from the die holder.
23. The die holder of claim 22 wherein one end of the clamp member is connected to the die holder body by a clamp hook or a pivotal connection for supporting said one end of said clamp member on the die holder body.
Type: Application
Filed: May 28, 2008
Publication Date: Dec 4, 2008
Applicant:
Inventors: Bruce M. Thielges (Fridley, MN), Alex M. Thell (Eagan, MN)
Application Number: 12/156,014
International Classification: B21D 37/00 (20060101);