GB2349596A

GB2349596A - Universal punch holder adaptor for punching machines

Info

Publication number: GB2349596A
Application number: GB9910304A
Authority: GB
Inventors: Giorgio Ostini
Original assignee: Tradewise Engineering Ltd; Euromac SRL
Current assignee: Tradewise Engineering Ltd; Euromac SRL
Priority date: 1999-05-04
Filing date: 1999-05-04
Publication date: 2000-11-08
Also published as: EP1050350A1; GB9910304D0; TR200001254A3; TR200001254A2

Abstract

A universal punch holder adaptor (1) for punching machines, comprising a cylindrical seat (3), which is mounted below the lower face of a hammer (4) and inside which a solid punch holder body (5) is accommodated, said body being rigidly coupled to the hammer and being provided with at least one blind and centered seat (6) for the insertion of punches (2), externally actuatable means (7) for the quick retention/release of the punches (2) in said seat (6) and means (10) for extracting the punch from the sheet metal being also provided.

Description

1 2349596 UNIVERSAL PUNCH HOLDER ADAPTOR FOR PUNCHING MACHINES The present

invention relates to a universal punch holder adaptor for punching machines.

Sheet metalworking uses punching machines provided with punches of different kinds according to the type of work to be performed.

Among the various punches, the type known as Trumpf or those known as "high-turret" punches are generally used most frequently.

However, up to now punching machines have been manufactured by presetting them specifically for the exclusive use of each one of said punches, so that if one wishes to have both types of punches available, it is necessary to purchase two punching machines, with an evident increase in costs and capital lockup and amortization.

Another drawback of conventional punching machines consists in that dunng the punching step the punch holder, regardless of its type, is unable to reach the level at which the sheet metal to be worked lies, because the elements that physically retain the punch, especially of the Trumpf type, in the punch holder have a considerable bulk and prevent this configuration ftom being achieved by interposing themselves in the clearance between the lower face of the punch holder and the sheet metal.

Particularly in the case of multiple punching operations to be performed in succession, this causes a warping of the sheet metal which reduces the precision of the work carried out.

The aim of the present invention is to solve the above problems of the prior art by providing a universal adaptor for punching machines which allows to rapidly replace, on a single machine, the punches to be used, without having to resort to the purchase of a plurality of punching machines, and which also allows to perform multiple punching operations without warping the sheet metal being worked.

This aim and other objects which will become more apparent herel'n'after 2 are achieved by a universal adaptor for punching machines, characterized in that it comprises a cylindrical seat, which is mounted so as to be rigidly coupled to the lower face of the hammer and inside which a solid punch holder body is rigidly inserted, at least one blind and centered seat for the insertion of the punches being formed in said body, externally actuatable means for the quick retention/release of the punches in said seat and means for extracting the punch from the sheet metal being also provided.

Further characteristics and advantages will become apparent from the description of a preferred embodiment of a universal adaptor for punching machines, illustrated only by way of non-Iiinitative example in the accompanying drawings, wherein, Figure I is a schematic and partially sectional side view of a punching head of a corresponding machine provided with the adaptor according to the invention, Figure 2 is a corresponding sectional plan view thereof, taken along the plane 11-11 of Figure I; Figures 3 and 4 are schematic side views of the punching head of Figure I during punching and at rest, Figures 5 and 6 are schematic views of an embodiment of means for the micrometric adjustment of the position of the solid body inside the cylindrical seat.

With reference to the above Figures, the reference numeral I designates a universal punch holder adaptor for punching machines.

The adaptor I substantially comprises a cylindrical seat 3 which is fitted below the lower face of a hammer 4 and inside which a solid punch holder body 5 is accommodated; said body is rigidly coupled to the hammer 4, and at least one centered and blind seat 6 is formed therein-, punches 2 are inserted in each instance in seat 6.

The adaptor I includes means 7 for quickly retaining or, viceversa, releasing the punches 2 in the seat 6, the means 7 are actuatable from the 3 outside by an operator.

Resilient means 8 which react by compression and act on the punches 2 are inserted in the blind bottom of the seat 6, while a pad 9 for resting on the sheet metal is rigidly coupled to the lower face 5a of the solid body 5; the pad 9 is made of flexible material and is arranged coaxially to the blind seat 6; the pad 9, which is a first possible embodiment of extractor means 10, is crossed axially by a perpendicular opening 9a in order to allow the passage of each punch during the active step of the punching machine.

Means 11 for the micrometric adjustment of the body 5 in the seat ') are provided in the adaptor 1, particularly between the cylindrical seat 3 and the solid body 5; such means 11 are described in greater detail hereinafter.

The extractor means 10, in an alternative embodiment shown in Figure 1, are constituted by a plurality of Belleville spring washers, which are generally designated by the reference numeral 4a, are fitted coaxially to the hammer 4 and rest and react on the upper rim of the cylindrical seat 3.

The quick release or retention means 7 are constituted by a plate 12 which is fitted so that it can move transversely back and forth in a corresponding seat 13 which has longitudinally larger dimensions, is formed horizontally in the solid body 5 and continues in the cylindrical seat 3.

The plate 12 can be actuated from the outside thanks to a corresponding actuation means 14 and is affected by a through slot 12a which defines a transverse edge 12b adapted to engage, m the retention configuration which is offset with respect to the punch 2 inserted in the seat 6, with a corresponding periMetric recess 2a usually formed in the punches 2; in the release position, the plate 12 is moved so as to be coaxial to the punch 2, allowing to extract it from the seat 6 by gravity.

The actuation means 14 comprises a button 14a which is transversely movable, in contrast with resilient return means 15, in a corresponding seat 16 formed horizontally on one side of the cylindrical seat 3 and the solid body 5, in alignment with one of the ends of the plate 12.

4 Spring means 17 are interposed between the plate 12 and the solid body 5 and are adapted to contrast the sliding thereof and return the slot 12a to its offset configuration with respect to the blind seat 6.

The means 11 for the micrometric adjustment of the position of the solid body 5 inside the cylindrical seat 3 are constituted by a cylinder 18 which is mounted so that it can rotate transversely in a corresponding through seat 19 which is in turn formed in said seat 3, the cylinder engages a corresponding seat 19a formed in the solid body 5 as an extension of the through seat 19.

The cylinder 18 has, perimetrically with respect to the proximal end that is directed outwards, a toothed ring 18a for coupling to means 21 for the rotary actuation thereof.

Such means are constituted by a key 22 which can be actuated manually or automatically and is provided with a tip 22a which has penmetric teeth M order to engage the toothed ring 1 Sa of the cylinder 18.

is The operation of the punch holder according to the present invention is as follows: the punches 2, of the Trumpf' type, of the high-turret type, or of another conventional type, are inserted m each instance in the hollow seat 6 formed in the solid body 5 that is part of the adaptor 1.

The plate 12 is moved by the operator by acting on the button 14a, so as to vertically align the slot 12a with the seat 6 and allow the selected punch 2 to pass in order to be seated, the punch is engaged by overcoming the action of the spring placed on the blind bottom of the seat 6, which constitutes the resilient means 8.

Once seating has been completed, the plate 12 is released and the sprig means 17 return it to a position in which it is axially offset with respect to the seat 6; in this position, the edge 12b fits under the recess 2a formed m the punch 2, retaining it in the seat 6.

The operator must then exactly align the axis of the punch 2 with the axis of the hammer 4; this is performed by acting on the key 22, turning the eccentric cylinder 18, which in turn moves the solid body 5 by a few tenths of a millimeter, by reaction and against the walls of the seat 19a, until the two axes coincide perfectly.

In this configuration, the punching machine is therefore ready to perform punching- the hammer 4 drops and, in the version of the adaptor I shown in Figure 1, moves not only the solid body 5 but also the cylindrical seat 3 until it is in contact with the sheet metal to be punched.

The punch 2 continues its stroke for a certain extent by being pushed by the hammer 4, which compresses the Belleville spring washers 4a in order to cover the additional extent and performs the punching action.

During the return stroke, the hammer gradually rises for the stroke for extracting the punch 2 from the hole while, until the stroke has been completed, the cylindrical seat 3 maintains the pressure on the sheet metal, preventing it from warping.

The hanimer then rises completely, pulling the cylindrical seat 3 and resuming the initial position for a subsequent punching operation.

In the other embodiment of the adaptor I shown in Figures 3 and 4, the punching operation occurs substantially as described above, with the only exception that the cylindrical seat 3 remains fixed during the stroke of the hammer 4 and of the solid body 5, as well as of the punch 2 fitted therein- the resilient pad 9 rests against the sheet metal.

The punch 2 then passes through the opening 9a formed in the pad during its active stroke and retracts during its return step, while the pad 9 maintains contact with the sheet metal throughout the extraction stroke of the punch 2, preventing any warping of the sheet metal.

In practice it has been observed that the described invention achieves the intended aim and objects.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.

All the details may furthermore be replaced with other technically equivalent ones.

6 In practice, the materials used, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.

7

Claims

1. A universal punch holder adaptor for punching machines, characterized in that it comprises a cylindrical seat, which is mounted below the lower face of the hammer and inside which a solid punch holder body is accommodated, said body being rigidly coupled to the hammer and being provided with at least one blind and centered seat for the insertion of the punches, externally actuatable means for the quick retention/release of the punches in said seat and means for extracting the punch from the sheet metal being also provided.

2. The adaptor according to claim 1, characterized in that resilient means which react to compression are interposed between the punches and the blind bottom of said seat.

3. The adaptor according to claim 1, characterized in that said extractor means comprise a pad made of flexible material for resting on the sheet metal, said pad being rigidly coupled to the lower face of said solid punch holder body and being coaxial to said blind seat, said pad being crossed axially by a perpendicular opening for the passage of the punches during the active step of the hammer.

4. The adaptor according to claim 1, characterized in that said extractor means comprise a plurality of Belleville spring washers which are fitted on said hammer and actively rest for contrast on the upper rim of said cylindrical seat.

5. The adaptor according to claim 1, characterized in that means for the micrometric adjustment of said body in said seat are provided between said cylindrical seat and said solid punch holder body.

6. The adaptor according to claim 1, characterized in that said quick retention/release means comprise a plate which is transversely movable back and forth within a corresponding longitudinally larger horizontal seat which is formed in said solid punch holder body and continues in said cylindrical seat, said plate being actuatable from the outside with a corresponding actuation means and being affected by a through slot which forms an edge which is 8 adapted to engage, in the retention configuration position which is offset with respect to the punches, a corresponding perimetric recess formed in said punches, or to align coaxially therewith, allowing their extraction by gravity.

7. The adaptor according to claim 6, characterized in that said actuation means complIses a button which is transversely movable, in contrast with resilient return means, in a corresponding seat formed horizontally on one side of said cylindrical seat and said solid punch holder body in alignment with one end of said plate.

8. The adaptor according to claim 7, characterized m that spring means for contrasting the sliding of said plate and for returmng the slot into an offset configuration with respect to said blind seat are interposed between said plate and said solid punch holder body.

9. The adaptor according to claim 1, characterized in that the lower edge of said cylindrical seat reaches by abutment the sheet metal during the active step for punching said sheet metal.

10. The adaptor according to claim 5, characterized m that said means for the micrometric adjustment of the solid punch holder body M the cylindrical seat comprise a cylinder which is mounted so as to rotate transversely and eccentrically a corresponding through seat which is formed m said seat and engages a corresponding seat formed in said solid body as an extension of said through seat, said cylinder being penmetrically provided, at the proximal end which is directed outwards, with a toothed ring for coupling to rotary actuation means.

11. The adaptor according to claim 10, characterized in that said means for the rotary actuation of said cylinde, comprise a manually-operated key which is provided with a tip which has perimetric teeth for said engagement with said toothed ring.

12. The adaptor according to claim 11, characterized in that said key can be actuated automatically.

13. A universal punch holder adaptor for punching machines, according to 9 one or more of the preceding claims, and substantially as herein described with reference to the accompanying drawings.