US3477270A - Coin press - Google Patents

Description

N 1969 K. FINSTERWALDER 3,477,270

COIN PRESS Filed Dec. 22. l96

United States Patent O 3,477,270 COIN PRESS Kurt Finsterwalder, Goppingen, Germany, assignor to L. Schuler GmbH, Goppingen, Germany Filed Dec. 22, 1966, Ser. No. 604,070 Int. Cl. B21d 22/00; B21j 7/26; B21c /00 U.S. Cl. 72359 5 Claims ABSTRACT OF THE DISCLOSURE A coin press comprising a frame and die holder together with a drivable ram, the ram and die holder being displaceable relative to the frame and to each other. A press ring is mounted adjacent the die holder and is displaceable by the ram under overload. Means are provided to immobilize the coin press dependently upon the displacement of the press ring.

This invention relates to a coin press with a press ring In known coin presses a coin or similar circular disclike article is pressed between the front face of the displaceable punch driven by the ram and the opposite face of a die which is stationary during pressing. The pressing process takes place in the opening of a press ring. Between the press ring and the die holder there is disposed a strong spring which, on the one hand, forces the press ring against an annular shoulder of the holder member for the press ring, on the other hand, however, holds the die in contact with a table receiving the pressing force. When the coin is to be ejected from the press ring the die is displaced axially against the effect of the spring until the front end of the die has pressed the coin out of the press ring from where it is then guided away. This known construction has the advantage that the die cannot only be displaced axially against the effect of this spring for the purpose of ejecting the coin out of the press ring, but it may also happen that when some irregularity occurs in the operating cycle the axially effective pressing force is applied at least partly to the press ring and the latter yields then driven back by the punch against the effect of the above mentioned spring. This however is the case always when for example the blank has a larger diameter than the central opening in the press ring. This is the case also when the blank is not applied by the feeder means exactly centrally in front of the opening of the press ring so that it cannot be inserted correctly centred in the opening of the press ring during the next following punch stroke. Also the press ring is pressed back by the punch when the diameter of the punch has assumed a larger diameter than the diameter of the opening in the press ring in consequence of a compression. In all practically occurring cases of disturbances the press ring is therefore forced back by the punch against the effect of the spring supporting it. Such a known press is produced and distributed for example by L. Schuler A. G. in Goppingen.

The known coin presses have overload protection devices which are mostly incorporated in the ram and respond when the pressing force exceeds a certain value. The invention is based on the problem to provide presses having a resiliently supported press ring with an overload protection device which can be produced in a simplified manner.

The invention consists in that the press is adapted to be switched olf dependently upon the movement of the press ring. The particular advantage of the invention resides in the fact that switching off protection devices which are directly actuated by the movement of the press ring can by produced very much more simply. For example according to one embodiment of the invention a movement of an actuating member causing the press to be switched off can be derived from the movement of the press ring. In this case the movement of the press ring may be detected mechanically and this mechanical movement may actuate directly an electrical contact. Such an embodiment of the invention is particularly simple and economical. This embodiment of the invention may be constructed in such manner that the feeler pin of an end switch rests against the press ring so that the switch is actuated when the press ring is forced back by the punch in the case of a disturbance.

In another embodiment of the invention switching off of the press may be derived from the movement of the press ring in such manner that the movement of the press ring is transmitted directly to a control valve controlling the hydraulic or pneumatic disengagement of the clutch and the initiation of the braking process.

Finally it is not absolutely necessary that in order I. to perform the invention the press ring is sensed medisplaceable under overload against the force of a spring.

chanically; under certain circumstances the movement of the press ring cannot be sensed mechanically. In such cases the press ring may be scanned for example by optical means and an appropriate control pulse released thereby which stops the press at once.

One embodiment of the invention will now be described by way of example with reference to the accompanying drawing which illustrates an axial section through the parts necessary for understanding the invention.

In the drawing a plunger 2 is attached to a driven press ram 1 and its leading end constitutes a press punch 3. A counter plunger 4 the end face of which lies opposite the press punch 3 is constructed as rearward press plunger or die and is supported by means of a die holder 5 on a face 6 of the press body or frame. The die holder 5 is guided axially displaceably in a recess 7 of the press body. The rearward face of the die holder 5 is engaged by an ejector rod 8. The one end of a helical spring 10 is supported on an annular shoulder 9 of the die holder 5. The spring has a relatively high spring force and rests with its other or forward end against the rear surface of a press ring 11 which has a collar 12 which rests on a corresponding inner shoulder 13 of a holder member 14 which is rigidly connected to the press frame. A plate 15 is attached to the front surface of the holder member 14 and in turn carries an end switch 16 a sensing pin 17 of which extends through an opening 18 in the plate 15 and rests against the front face of the press ring 11. The press ring has a central opening 19.

A blank is applied in front of the opening 19 of the press ring by means of a feeder device not illustrated and is then inserted by the plunger 2 into the opening 19 of the press ring 11. The counter plunger 4 is disposed in the opening 19 of the press ring 11 and the blank is pressed by the plunger 2 within the opening 19 of the press ring 11 against the counter plunger 4, the punch of the plunger 2 coin-pressing the one side of the blank, in the present example a coin 20, the rearward press punch or die on the plunger 4 coin-pressing the other side of the coin 20. After the pressing process the plunger 2 travels back and the counter plunger 4 is displaced axially forward to gether with its holder 5 by means of the ejector rod 8 against the force of the spring 10 so that the plunger 4 forces the coin out of the press ring and the coin can be guided away. When a disturbance occurs, for example if a blank having too large a diameter is supplied in front of the opening 19, if a blank is not applied exactly centrally in front of the bore 19, or if the plunger 2 is slightly compressed or distorted so that it does not enter any more in the opening 19, the forward moving plunger 2 presses the press ring 11 back against the force of the spring 10. Then however the front face of the press ring tends to move away from the sensing pin 17 of the end switch 16, the end switch is actuated in that a contact is opened or colsed therein and the control signal produced thereby stops the press at once, The end switch may be disposed alternatively at a different location, it being essential only that the movement of the sensing pin 17 of the end switch 16 is derived either directly from the movement of the press ring 11 in that the sensing pin rests against the pressing ring 11, or however the movement of the press ring is transmitted to the sensing pin of the end switch intermediate by mechanical members. The end switch 16 may alternatively be disposed at a suitable location within the holder 40 for the press ring, or at another suitable part of the machine.

What I claim is:

1. A coin press comprising a frame, a die holder means, a ram, and driving means for said ram, said die holder means and said ram mounted on said frame displaceable relatively to said frame and relatively to each other, said die holder means adapted to receive a die, a press ring mounted adjacent said die holder means and displaceable by said ram under overload, and means for immobilising said press dependently upon displacement movement of said press ring.

2. A coin press comprising a frame, a die holder means, a ram and driving means for said ram, said die holder means and said ram mounted on said frame displaceable relatively to said frame and relatively to each other, said die holder means adapted to receive a die, a press ring a mounted adjacent said die holder means and displaceable under overload against the force of a spring by said ram, switching means disposed on said press and operatively connected to said press ring, said switching means arranged to immobilise said press dependently upon displacement movement of said press ring.

3. A press according to claim 1, characterised in that a movement of an actuating member causing the press to be switched off is derived from the displacement movement of the press ring.

4. A press according to claim 1, characterised in that the press ring is connected to an actuating member for an electrical contact.

5. A press according to claim 4, characterised in that an end switch having a sensing pin which rests against the press ring is disposed at the front plate of a holder member for the press ring.

References Cited UNITED STATES PATENTS 1,642,736 9/1927 Lyman 72354 2,134,933 11/1938 Smith 723 3,319,087 5/1967 Wintriss 7226 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R. 724, 26, 31

Images