GB2161733A

GB2161733A - Punch press

Info

Publication number: GB2161733A
Application number: GB08417495A
Authority: GB
Inventors: Robert Frederick Gardner
Original assignee: SEAGAR CONTROL SYSTEMS Ltd
Current assignee: SEAGAR CONTROL SYSTEMS Ltd
Priority date: 1984-07-09
Filing date: 1984-07-09
Publication date: 1986-01-22
Also published as: GB8417495D0

Abstract

A punch press comprises a transversely movable carrier 20 mounting a plurality of dies and a transversely movable carrier 24 mounting a plurality of corresponding punches. The movable carriage 10, which mounts clamps 12 for gripping a rear edge of the workpiece 14, carries an actuating element 34 which is arranged to engage the die and punch carriers, when required, to move these carriers to selected positions by movement of the carriage, so that an actuating ram 26 of the press can then act upon the selected punch. <IMAGE>

Description

SPECIFICATION Punch press This invention relates to a punch press.

A known punch press comprises a carriage which mounts say two workpiece clamps for gripping the rear edge of a workpiece (typically a sheet of metal): the carriage is movable along a horizontal beam which is disposed transverse of the press, and the beam is movable along a horizontal axis perpendicular to itself (i.e. lengthwise of the press).

The movements may be controlled by computer numerical control and serve to position the workpiece accurately at successive required locations relative to a punch (and its aligned die) of the machine prior to actuation of the punch at each such location, by its ram.

Various arrangements are known wherein different punches and dies may be selected during the course of operation (e.g. the turret punch press), but in these an additional drive means is required to move the selected punch and die into alignment with the actuating ram.

In accordance with this invention, as seen from one aspect, there is provided a punch press comprising a movable carrier mounting a plurality of dies and a movable carrier mounting a plurality of corresponding punches, a movable carriage mounting workpiece clamps for gripping a rear edge of the workpiece, and an actuating element carried by the workpiece carriage and arranged to engage the die and punch carriers to move these carriers to selected positions by movement of the carriage. It will be seen that, in this machine, the drive means for the carriage is made use of for changing the die and punch and no separate drive means for this is required.

Conveniently the die and punch carriers are elongate shuttles movable transverse of the press, with the dies and punches spaced apart lengthwise of the shuttles. For displacing the shuttles, the workpiece carriage is advanced to a forwardly position and a bolt or similar element is displaced vertically from one shuttle and into engagement with the other shuttle, at a position now rearwardly of the rear edge of the workpiece. A further element projecting forwardly from the workpiece carriage now serves to engage the bolt and, by a transverse displacement of this carriage, to displace both the die and punch shuttles along their lengths until the selected die and punch are aligned below the actuating ram. The bolt is now retracted and the carriage is again employed for positioning the workpiece.

Also in accordance with this invention, as seen from another aspect, there is provided a punch press comprising a relatively large actuating ram and a relatively small actuating ram, and dies and punches for co-operating with the respective rams.

The relatively large ram is required for relatively heavy duty uses, but is limited in its rate of operation, and the smaller ram is able to operate at higher rates for the lighter duty uses. Conveniently the two rams may be at fixed positions spaced transversely of the machine, with transversely movable shuttles mounting a plurality of dies and punches, respectively, at spacings to which the spacing of the two rams is a multiple.

An embodiment of this invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic plan view of portions of a punch press in accordance with this invention; and Figure 2 is a diagrammatic side view of the punch press; Referring to the drawings, there is shown a punch press having an elongate carriage 10 which mounts two workpiece clamps 12 for gripping a workpiece 14 along its rear edge. The carriage 10 is mounted to and movable along a horizontal beam 16 which is disposed transverse of the press, and the beam 16 is movable along a horizontal axis perpendicular to itself (i.e. lengthwise of the press).These movements are controlled by computer numerical control and serve to position the workpiece accurately at successive required locations relative to a punch, and its aligned die, prior to actuation of the punch at each such location, by its ram.

In the punch press shown, a plurality of dies 18 are mounted in an elongate shuttle 20 and a plurality of corresponding punches are mounted in an elongate shuttle 24. The two shuttles are movable transverse of the machine to position any selected one of the punches, and the corresponding one of the dies 18, in alignment below a ram 26 which serves to actuate the punch. Displacement of the shuttles, when a different punch and its corresponding die are to be selected, is effected by temporarily coupling the carriage 10 to both shuttles and then effecting appropriate displacement of the carriage lengthwise of the shuttles. This is carried out as follows.

Firstly the carriage 10 is advanced to bring the workpiece to a forwards position. Then a vertical bolt 28 is extended from one shuttle (e.g. the lower one) so as to engage with a corresponding bore in the other shuttle: the bolt 28 is carried by a rearwardly extending arm 30 on the one shuttle and engages into a corresponding arm 31 on the other shuttle, such that the bolt travels in the space rearwardly of the workpiece (and preferably the workpiece clamps extend forwards more than usual from the carriage to create this space). The carriage is now displaceable for a notch 32 in a forwards projection 34 from this carriage to engage the bolt, such that the carriage can now be moved transverse of the machine to displace both die and punch shuttles to the required new position, bringing the newly selected punch and die into alignment with the ram 26.The bolt 28 is finally retracted and the machine is operated normally again.

Preferably in each position of the two shuttles, locking pins are extended (e.g. rearwardly from a front mounting of the machine) into locating recesses of the shuttles, so as to lock them in position.

The bolt 28 may further be used when repositioning the workpiece. Thus the bolt may be extended to clamp the workpiece, whilst the workpiece clamps 12 are temporarily released, the carriage displaced, and the workpiece clamps applied again. The bolt 28 may yet further be used, when extended, as a datum reference position for the workpiece.

The punch press shown further includes a second, relatively small ram 36 at a transverse spacing from the larger ram 26 which corresponds to a multiple of the spacing between adjacent dies.

Thus when one die/punch pair is aligned with one ram, another die/punch pair is aligned with the other ram. As mentioned previously, the larger ram 26 serves for the required heavy duty uses, but the smaller ram 36 serves instead for the lighter duty uses and is capable of a higher rate of actuation (for such uses) than the larger ram. The provision of the two rams also enables a reduction in the number of tool changes which are required.

When the provision of the two rams as just described, it may be desirable for the shuttles to be displaceable other than by the carriage, in order to effect a change from one die/punch pair to another more swiftly. In such a case a drive means for each shuttle will be provided, or just a single drive means for one shuttle whilst the bolt 28 is still provided to couple the shuttles together when a dis placement is needed.

Claims

1. A punch press comprising a movable carrier mounting a plurality of dies and a movable carrier mounting a plurality of corresponding punches, a movable carriage mounting workpiece clamps for gripping a rear edge of the workpiece, and an actuating element carried by the workpiece carriage and arranged to engage the die and punch carriers to move these carriers to selected positions by movement of the carriage.

2. A punch press as claimed in claim 1, in which the die and punch carriers are elongate shuttles movable transverse of the press, with the dies and punches spaced apart lengthwise of the respective shuttles.

3. A punch press as claimed in claim 2, in which an element is provided for displacement vertically from one shuttle and into engagement with the other shuttle, for coupling the two shuttles for movement together with each other.

4. A punch press as claimed in claim 3, in which the actuating element carried by the workpiece carriage is arranged to engage said vertically displaceable element, for effecting movement of said shuttles.

5. A punch press as claimed in any preceding claim, comprising a relatively large actuating ram and a relatively small actuating ram, for co-operating selectively with the punches.

6. A punch press comprising a relatively large actuating ram and a relatively small actuating ram, and dies and punches for co-operating selectively with the respective rams.

7. A punch press as claimed in claim 6, in which the two rams are at fixed positions spaced transversely at the press, the press further comprising transversely movable shuttles mounting a plurality of dies and punches, respectively, at spacings to which the spacing of the two rams is a multiple.