GB2053743A

GB2053743A - Strip steel punching tool

Info

Publication number: GB2053743A
Application number: GB8021865A
Authority: GB
Original assignee: Karl Marbach GmbH and Co KG
Current assignee: Karl Marbach GmbH and Co KG
Priority date: 1979-07-18
Filing date: 1980-07-03
Publication date: 1981-02-11
Also published as: GB2053743B; DE2929015C2; FR2461558B1; DE2929015A1; NL8003522A; SE8005209L; FR2461558A1; CH648233A5

Abstract

A strip steel punching or stamping tool comprises steel sections (2,3) for cutting, profiling or grooving, located in slots (21,22,23) formed in a support plate 1 by means of laser beams. The support plate is constructed as a plural- layered, at least partly moisture- insensitive composite plate and com- prises at least one rigid guide plate (5,6) of e.g. acrylic plastics, and a holding plate (7) of elastic material e.g. rubber, the slots (21,23) in the guide plates (5,6) being wider than the slot (22) in the holding plate (7). The plates 5-7 are secured together by means of counter- sunk screws (11) before the slots are formed. <IMAGE>

Description

SPECIFICATION Strip steel punching tool This invention relates to a strip steel punching or stamping tool with a support plate in which slots are made by means of laser beams. Strip steel sections for cutting, profiling, grooving, etc., projecting beyond the support plate are introduced into said slots. In known tools of this type the support plate is made from wood, which is hygroscopic, so that difficulties occur with regard to the dimensional stability in the case of moisture changes. Using such tools, high-performance machines perform for example 21,000 strokes per hour and the temperature in the punching area can reach up to 70"C. Thus, the moisture level is reduced, the support plate shrinks, and the dimensions change on punching.

The present invention aims to provide a strip steel punching tool which maintains its dimensional stability, even at elevated temperatures, but which can still be manufactured in an accurate and inexpensive manner.

According to the invention, there is provided a strip steel punching tool comprising a support plate in which slots are made by means of laser beams and in which are introduced strip steel sections for cutting, profiling, grooving, etc., which project beyond the support plate, wherein the support plate is constructed as a multilayered, moistureinsensitive composite plate and comprises at least one guide plate and at least one holding plate, the guide plate(s) being made from a rigid material and the holding plate being made from an elastic material and the slots made in the composite plate by laser beams are wider in the guide plate(s) than in the holding plate.As a result, the strip steel sections inserted in the slots are securely held and external influences such as moisture and temperature have no influence on the position of the strip steel sections, even if the guide plates are influenced thereby. Manufacture is just as easy as when using conventional wooden plates, because the composite plate is exposed as an entitiy to the laser beams for making the slots.

The width of the slot(s) in the guide plate(s) can be approximately 0.02 mm more than the thickness of the strip steel sections, generally approximately 0.71 mm. Whereas the or each guide plate is desirably made from a plastics material, preferably acrylic glass, the holding plate may be a rubber plate or a plate made from a rubber-like material, particularly a textile plastics material. The rubber plate is relatively tbin preferably being approximately 8 times thinner than the guide plates. It has proved particularly advantageous to have a guide plate thickness of 8 mm and a holding plate thickness of 1 mm. The strip steel sections pass through the entire thickness of the composite plate. One side thereof is preferably flush with the guide plate surface, whilst the working side thereof desirably projects approximately 6 mm above the guide plate surface.

According to another feature of the invention the holding plate is fixed between two guide plates, the plates being secured to one another by screws.

The invention will now be further described, by way of example, with reference to the drawings in which Figure lisa plan view of one embodiment of a strip steel punching tool according to the invention; and Figure 2 is a section taken along the line ll-ll in Figure 1 on a larger scale.

Referring to the drawings, the strip steel punching tool comprises a support plate 1 in which are located strip steel sections 2,3. The support plate 1 is constituted by a composite plate 4 which, in the illustraed embodiment, is formed from two guide plates 5, and a holding plate 7. The guide plates 5,6 are made from acrylic glass, such as that known for example under the trade marks "Plexiglas" (Registered Trade Mark). "Paraglas" or "Lucite". The holding plate 7 is made from rubber and its thickness 8 is only 1/8th that of the thickness 9, 10 of the guide plates 5, 6. The plates 5, 6, 7 are pressed on to one another by screws 11, the heads 12 of the screws 11 being flush with the surface 14 of one guide plate 5, whilst the guide plate 6 is provided with screwthreaded bores 15 (only one shown) for screwing in the screws 11.For fixing and adjustment it is possible to use slotted pins, cylindrical pins, etc. (not shown). The strip steel sections 2, 3 pass through the entire composite plate 4. One side 16 thereof is flush with the surface 17 of the guide plate 6 and the working side 18 thereof projects beyond the surface 14 of the guide plate 5. The strip steel sections 2,3 have a thickness 19 of preferably e.g. 0.71 mm. The sections are used for cutting and therefore have a cutting edge 20, which projects beyond the working side 18 of the sections 3, which latter are rounded and are used for forming grooves. The strip steel sections 2,3 are held in a web-like manner by notches in the vicinity of the plates 5,7. They are placed in interrupted slots 21, 22,23 of or the support plate 1, all of which are made by laser beams.As a result of the interruption in connection with the notches a high strength is obtained, as in a latticework structure. The different materials of the plates 5, 6 and 7 lead to different slot widths, so that the slots 21 and 23 are wider than the slot 22 in the holding plate 7. The strip steel sections 2,3 inserted in the slots 21,22 and 23 are consequently mainly secured by the holding plate 7. The width 24 of slot 22 is slightly less or at the most equal to the thickness 19 of the strip steel sections 2 and 3 and the width 25 of slots 21 and 23 in the guide plates 5 and 6 is approximately 2/100 mm greater than the thickness 19 of the strip steel sections 2,3.

Firstly composite plate 4 is assembled. The slots 21 to 23 are then made by laser beams. The strip steel sections 2,3 are then driven in until one side 16 thereof is flush with the surface 17, whereby the latter is supported against a smooth surface of a rigid plate on introducing the sections 2,3 or when working with the tool. In the present embodiment, the thicknesses 9, 10 of the guide plates 5,6 are approximately 8 mm. The thickness 8 of the holding plate 7 is approximately 1 mm. Strip steel sections 2, 3 project approximately 6 mm beyond the surface 14 of the guide plate 5.

Claims

1. A strip steel punching tool comprising a support plate in which slots are made by means of laser beams and in which are introduced strip steel sections for cutting, profiling, grooving, etc., which project beyond the support plate, wherein the support plate is constructed as a multilayered, moistureinsensitive composite plate and comprises at least one guide plate and at least one holding plate, the guide plate(s) being made from a rigid material and the holding plate being made from an elastic material, and the slots made in the composite plate by laser beams are wider in the guide plate(s) than in the holding plate.

2. A tool according to claim 1, wherein the width of the slot(s) in the guide plate(s) is/are approximately 0.02 mm greater than the thickness of the strip steel sections.

3. Atool according to claim 1 or claim 2, wherein the or each guide plate is made from a plastics material.

4. A tool according to claim 3, wherein the or each guide plate is made from acrylic glass.

5. Atool according to any preceding claim, wherein the holding plate is made from rubber or a rubber-like material.

6. Atool according to any preceding claim, wherein the holding plate is secured between two guide plates.

7. A tool according to claim 6, wherein the plates are secured to one another by means of screws.

8. A tool according to claim 7, wherein the screw heads are countersunk in one guide plate and the other guide plate is provided with screw-threaded bores.

9. Atool according to any preceding claim, wherein the thickness of the or each guide plate is approximately eight times the thickness of the holding plate.

10. A tool according to claims 6 and 9, wherein the two guide plates have a thickness of in each case 8 mm and the holding plate has a thickness of 1 mm, one side of the strip steel sections is flush with the outer surface of one guide plate and the working surface of said steel sections projects approximately 6 mm beyond the outer surface of the other guide plate.

11. A strip steel punching tool substantially as described herein with reference to the drawings.