DEVICE FOR PUNCHING THIN-WALLED MATERIALS

Abstract

A device by which thin-walled materials, such as labels and flat lids for containers, can be punched in micro or small quantities. The device includes a band steel cutting edge (11) that is elastically mounted in the punching direction. The matrix is likewise elastically held on the matrix plate perpendicular to the punching direction by virtue of a matrix seat (33) fastened to the region in the matrix plate (27) that is adjacent to the opening (29). On the matrix seat, an elastically deformable intermediate plate (47) is placed, and the matrix (55) is placed on the intermediate plate.

Claims

1. A device for punching thin-walled materials, comprising labels and flat lids for container in micro and small quantities, comprising a punching plate (1) for receiving a blade (11, 61) and a matrix (55) on a matrix plate (27), with the blade (11, 61) and the matrix (55) being supported in a punching machine in a fixable and mutually displaceable fashion, in order to punch labels and lids comprising paper, plastic, metal, or a laminate from a material tape guided therebetween, with the matrix plate (27) for carrying the matrix (55) comprising a recess (29) for guiding the punched out work pieces therethrough, a matrix seat (33) is fastened on an edge section of the matrix plate (27) abutting the recess (29), an elastically deformable intermediate plate (47) rests on the matrix seat (33), and the matrix (55) rests on the intermediate plate (47).

2. The device according to claim 1, wherein the matrix (55) is guided without play in an X- and a Y-direction by fastening pins (45) and is held in a Z-direction, guided in an elastically displaceable fashion.

3. The device according to claim 1, wherein the matrix seat (33) is inserted and fastened in a step (31) surrounding the recess (29).

4. The device according to claim 2, wherein the intermediate plate (47) and the matrix (55) rest on the matrix seat (33) and are held guided by the fastening pins (45).

5. The device according to claim 4, wherein the fastening pins (45) are guided in guide sleeves (43) which are inserted in the matrix seat (33).

6. The device according to claim 5, further comprising magnets (39) inserted in the guiding sleeves (43) for pulling in the fastening pins (45) and holding the matrix (55).

7. The device according to claim 1, wherein the intermediate plate (47) is formed elastically perpendicular to a surface thereof and comprises a surface coated with an elastic material or is made in its entirety from an elastic material.

8. The device according to claim 1, wherein a recess (3) is formed in the punching plate (1).

9. The device according to claim 8, further comprising a spring-elastic compensating element (7) inserted on a bottom of a groove (5) comprising the recess (3).

10. The device according to claim 9, further comprising a blade holder (9) is arranged in the groove (5) above the spring-elastic compensating element (7).

11. The device according to claim 10, wherein the blade holder (9) is formed U-shaped.

12. The device according to claim 11, wherein the blade holder (9) comprises a first and a second leg (9, 9), with a band steel blade (11) being inserted between the legs (9, 9) of the U-shaped blade holder (9), and a cutting edge (17) projects beyond the blade holder (9).

13. The device according to claim 12, wherein the blade holder (9) in the groove (5) is elastically supported on the compensating element (7) and is held by holding elements (15) in the groove, which engage the punching plate (1).

14. The device according to claim 8, further comprising a compensating element (7) inserted on a bottom of a groove (5) comprising the recess (3).

15. The device according to claim 14, further comprising a magnetic blade support formed as a supporting ring (67) arranged in the groove (5) above the compensating element (7).

16. The device according to claim 15, further comprising a support plate (59) with a blade (61) embodied as a bead rests on the support ring (67) and is held by the magnetic support ring (67).

17. The device according to claim 16, further comprising a plurality of magnets (71) inserted in the support ring (67) by which the support plate (59) with the cutting bead (61) is held.

18. The device according to claim 1, further comprising at least one ejecting device (21) with an ejection plate (19) arranged at the punching plate (1) by which punched out work pieces are ejectable through the recess (29) in the matrix plate (27) into a stacking channel (73).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0015] Based on an illustrated exemplary embodiment the invention is explained in greater detail. It shows:

[0016] FIG. 1 an exploded illustration of a punching plate of a punching device with a punch blade and its support structure in the punching plate, viewed from the left,

[0017] FIG. 2 a vertical section through the punching plate and the ejector,

[0018] FIG. 3 an enlarged illustration of detail A in FIG. 2,

[0019] FIG. 4 a view of the punching plate from the bottom with assembled cutting elements,

[0020] FIG. 5 a perspective view of the punching plate,

[0021] FIG. 6 a perspective illustration of a matrix plate from the top with matrix elements shown in an exploded illustration,

[0022] FIG. 7 a top view of an assembled matrix plate,

[0023] FIG. 8 a vertical section through a matrix plate,

[0024] FIG. 9 an enlarged illustration of the detail D in FIG. 8,

[0025] FIG. 10 an enlarged illustration of the magnetic fastener for the matrix plate according to FIGS. 6-9, and

[0026] FIG. 11 a perspective illustration of another embodiment of the punching die (without punching plate) in a perspective exploded illustration from the bottom according to the Figure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] In FIG. 1, which shows the punching plate 1 in a perspective illustration from the bottom, a recess 3 is discernible in the central area, around which a groove 5 is inserted. The groove 5 serves for receiving a compensation element 7 and a blade holder 9. The blade holder 9 has, as shown in the cross-section, the shape of an upside-down U. Further, a band steel blade 11 is discernible in FIG. 1. The band steel blade 11 is sized such that it can be inserted between the two legs 9, 9 of the blade holder 9, and is held there (also see FIGS. 2 and 3 for reference). It is also discernible from FIG. 3 that the compensation element 7 has a cross-section in a trapezoidal form. Further it is discernible that the blade holder 9 can be inserted precisely fitting in the groove 5 and can be connected by a fastening plate 13 and a screw 15 to the punching plate 1. The blade holder 9 is fixed in the punching plate via the fastening plate 13 and the screw 15. An arrangement of the fastening plates 13 is discernible in FIG. 4. The cutting edge 17 of a band steel blade 11 projects beyond the blade holder 9 by a few tenths of a millimeter. The facial areas of the legs 9 and 9 of the blade holder 9 project in turn beyond the bottom of the punching plate 1 by a few tenths of a millimeter. Further, an ejection plate 19 is shown in FIGS. 1 to 4, with its cross-section being smaller than the internal cross-section of the recess 3 in the punching plate 1 (cf. FIGS. 1 and 3). The ejection plate 19 preferably comprises a plurality of bores or holes 23 in order to avoid at the end of the ejection process any adhesion of the punched-out work piece due to a vacuum. The ejection plate 19 is actuated by at least one ejection device 21. The punched work piece is conveyed with this ejection device 21 from the punching plate 1 downwards into a stacking channel 73 (see FIG. 6). Any operation of the ejection device 21 can occur pneumatically or via a servo drive. The design of the ejection device 21 arranged at the rear of the punching plate 1 is not described in greater detail (see FIGS. 3 and 5). FIG. 5 shows the punching plate 1 from the top and thereon in turn a first and a second ejection device 21 are discernible. Further, the fastening elements for the punching plate 1 are discernible at a punching machine, not shown. These elements are not described in greater detail. Guide sockets 25 are drawn in the proximity of the two narrow sides of the punching plate 1 for a precise vertical guidance of the punching plate 1.

[0028] The FIGS. 6 to 10 show the matrix plate 27. The perspective illustration of the elements of the matrix plate 27 shows the latter in a view diagonally from the top. A penetrating opening 29 for the work pieces is discernible in the matrix plate 27. The edge of the penetrating opening 29 is embodied as a step 31. A matrix seat 33 rests on this step 31. The matrix seat 33 is fastened with screws 35 on the step 31 at the matrix plate 27. Bores 37 are formed in regular intervals at the matrix seat 33, which serve to receive respectively one permanent magnet 39 each (see FIGS. 9 and 10). Each permanent magnet 39 is here fastened locally fixed in a guide sleeve 43 provided for this purpose. The axial length and/or height of the permanent magnets 39 are sized such that a small clearance 41 develops between the top of the permanent magnets 39 and the bottom edge of the fastening pins 45. The fastening pin 45 comprises a flange 49 at its upper end.

[0029] An intermediate layer 47 comes to rest over the matrix seat 33. The intermediate layer 47 is made from a thin sheet metal, which comprises at the top and/or bottom a coating made from rubber or another rubber-elastic material. Alternatively the intermediate plate 47 could also be produced in its entirety from an elastic material. Bores 53 are provided in the intermediate plate 47, which are arranged directly above the bores 37 in the matrix seat 33. The bores 53 have a diameter which allows guiding fastening pins 45 through them with little play. A matrix 55 comes to rest above the intermediate frame 51. A flap-like bulge 57 is formed at the exterior edge of the matrix 55, in which a penetrating recess allows guiding the fastening pins 45, also called positioning pins. The bulges 57 are sized such that the flange 49 of the fastening pins 45 can rest on it. When all elements holding the matrix 55 are assembled, the matrix is pulled by the permanent magnets 39 and the fastening pins 45, made from steel, to the matrix seat 33 and/or the matrix plate 27 and held in place. By the elastic embodiment of the intermediate layer 47 the matrix 55 is held precisely in the horizontal plane (X/Y-direction), on the one side; in the vertical direction (Z-direction) it is slightly supported in an elastic fashion.

[0030] In another embodiment of the invention according to FIG. 11, instead of a band steel blade formed like a bead on the support plate 59, here a blade 61 is provided showing a triangular cross-section. The support plate 59 comprises a thin metal sheet on which the blade 61, is applied for example as a bead made from a high-strength steel or a suitable steel alloy and by a cutting process has been turned into a blade 61. The support plate 59 comprises at least a bore 63 at its four corners, through which a positioning pin 65 each can be guided with little play and is held in the punching plate 1. The support plate 59 is located, similar to the first embodiment according to the FIGS. 1 to 5, in the area underneath the blade 61 on a support ring 67 or a support ring 67 with a magnet 71 inserted therein, which matches the first embodiment of the blade holder 9. The support ring 67 in turn rests on a compensating element 69. The compensating element 69 matches the one with the reference character 7 of the first exemplary embodiment. The compensating element 69 and the support ring are held resting on the punching plate 1. The compensating elements 7 and 69 are made from plastic, e.g., polyurethane (PE). They carry the blades in a resilient fashion.

[0031] In both embodiments of the invention the band steel blade 11 and/or the blade 61 are supported resiliently on the support plate 59 in the Y-direction, i.e. perpendicular to the surface of the punching plate 1. This embodiment allows and/or causes that during the punching process of a work piece, regardless if it comprises paper, metal, or a plastic film, the cutting force can be distributed evenly over the entire perimeter of the work piece. Any potential differences in thickness of the work piece or tolerances in the tool are here compensated by 100%. On the one hand, therefore the cutting process can occur with a moderate cutting force, which the punching machine can easily compensate, and on the other hand the cutting occurs securely along the entire perimeter of the work piece evenly and thus completely. Experiments have shown that the cutting force of elastically supported blades can be reduced by up to 90%.