EP0295910A1

EP0295910A1 - Integrated cutting blade assembly

Info

Publication number: EP0295910A1
Application number: EP19880305499
Authority: EP
Inventors: Muneharu C/O Taci-S Co. Ltd. Urai; Takao Tachikawa Kogyo Sasaki
Original assignee: Tachi S Co Ltd
Current assignee: Tachi S Co Ltd
Priority date: 1987-06-19
Filing date: 1988-06-16
Publication date: 1988-12-21
Anticipated expiration: 2008-06-16
Also published as: JPS63318296A; DE3860734D1; EP0295910B1

Abstract

An integrated cutting blade assembly for cutting sheet members comprises a plurality of main blade sections (3A) and a plurality of common blade sections (3B), the main blade sections (3A) being integrally welded (W) to adjacent ones of the common blade sections (3B) to form a plurality of cutting blades. The integrated cutting blade assembly eliminates the loss of materials of the sheet members when compared to the use of a plurality of independent cutting blades having gaps between them.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to an integrated cutting blade assembly used for cutting sheet members. There are various sheet members including surface cover members, members forming surfaces of articles of furniture, thin sheets of wood sheets of rubber, sheets of paper, etc., and they find wide ranges of applications. The integrated cutting blade assembly of the present invention is especially advantageously utilized for cutting surface cover members covering the surface of seat, etc. installed in automobiles.

Description of the Prior Art

Surface cover members such as trim covers or moquettes used as covers for seats of automobiles are mass-produced by cutting a plurality of such surface cover members of standard dimensions at the same time by a set of cutting blades sized to conform to the desired shapes of the surface cover members. For example, according to a prior art practice, a plurality of cutting blades 1A, 1B and 1C as shown in Fig. 11a are prepared, each of which is formed by bending a steel plate into the desired shape and welded endwise as shown at W in Fig. 11a. Such cutting blades are juxtaposed on a table 5 of a press as shown in Fig. 11b, and, after placing a web of surface cover providing material on the cutting blades 1A to 1C, an upper plate (not shown) of the press is forced downward to cut the web into the desired surface cover members at the same time. According to another prior art practice, cutting blades 2A to 2E of various shapes required for cutting various parts of the surface of a seat are arranged as shown in Fig. 12a and, after being partly embedded and fixed in a plywood board 6 as shown in Fig. 12b, the assembly is placed on a table 5 of a press.
However, because of the fact that the cutting blades used in such a prior art cutting process require the presence of gaps t between them, the portions of the surface cover providing material corresponding to the gaps t are inevitably wasted. Especially, in the prior art practice shown in Figs. 11a and 11b, the cutting blades 1A to 1C must be accurately positioned on the table 5 of the press in each cutting process, resulting in consumption of a correspondingly long period of time for positioning. Although the cutting blades need not be positioned in each cutting process in the case of the prior art practice shown in Figs. 12a and 12b, embedding of the cutting blades in the plywood board 6 increases the total weight of the cutting blade assembly, resulting in consumption of a correspondingly long period of time for accurately setting the cutting blade assembly on the table 5 of the press.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an integrated cutting blade assembly which obviates the prior art defects described above.
In accordance with the present invention, there is provided an integrated cutting blade assembly for cutting sheet members, comprising a plurality of main blade sections, and a plurality of common blade sections, the main blade sections being integrally welded to adjacent ones of the common blade sections to form a plurality of cutting blades.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1a is a plan view showing state of a first embodiment of the present invention before welding.
Fig. 1b is a plan view showing the state of the first embodiment after welding.
Fig. 2a is a plan view showing the state of a second embodiment of the present invention before welding.
Fig. 2b is a plan view showing the state of the second embodiment after welding.
Fig. 3 is a plan view showing pipes fixed to the integrated cutting blade assembly shown in Fig. 2b.
Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3.
Fig. 5 is an enlarged plan view of part of the second embodiment to show a weld when the angle between adjacent blade sections is 90°.
Figs. 6 and 7 are enlarged sectional views of part of the first embodiment to show welds when the angle between adjacent blade sections is smaller than 90°.
Fig. 8 is an enlarged sectional view to show how a stress is produced in the first embodiment when the welds differ from those shown in Figs. 6 and 7 although the angle between the adjacent blade sections is smaller than 90°.
Figs. 9 and 10a are enlarged sectional views to show different shapes of the edge of the main blade section in the first embodiment.
Fig. 10b is an enlarged sectional view taken along the line Xb-Xb in Fig. 6.
Fig. 11a is a plan view showing prior art cutting blades juxtaposed on a table of a press.
Fig. 11b is a sectional view taken along the line XIb-XIb in Fig. 11a.
Fig. 12a is a plan view of prior art cutting blades partly embedded in a plywood board.
Fig. 12b is a sectional view taken along the line XIIb-XIIb in Fig. 12a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of the integrated cutting blade assembly of the present invention shown in Figs. 1a and 1b corresponds to the prior art example shown in Fig. 11a. The integrated cutting blade assembly shown in Figs. 1a and 1b is intended to cut three sheet members having a shape substantially the same as that of sheet members cut by the three cutting blades 1A, 1B and 1C shown in Fig. 11a. This integrated cutting blade assembly of the present invention comprises a plurality of outer main blade sections 3A and a plurality of inner common blade sections 3B and 3C. Such an assembly is formed by the steps of bending a web of steel into a form having three semicircular sections in each half as shown in Fig. 1a, forming a flat bottom, welding the bent web of steel endwise as shown at a weld W in Fig. 1b, thereby forming the outer main blade sections 3A, preparing inner common blade sections 3B and 3C by cutting from a similar web of steel, and welding these common blade sections 3B and 3C at their ends to the constrictions between the semicircular main blade sections 3A respectively as shown at welds W in Fig. 1b.
When the angle α between the adjacent main blade sections 3A on both sides of the constriction is smaller than 90° as shown in Fig. 6 or 7, these sections 3A are formed by bending a web of steel, and the common blade section 3B or 3C is welded to the constriction as shown at a weld W in Fig. 6 or 7. Assume, on the contrary, the case where the common blade section 3B or 3C and one of the adjacent main blade sections 3A are formed by bending a web of steel to make an obtuse angle as shown in Fig. 8, and the other main blade section 3A is welded to the common blade section 3B or 3C as shown at welds W in Fig. 8. In such a case, there is the relation P> P′ between the pressure P imparted to the cutting blade assembly by a sheet member being cut in the area of the angle α and the external pressure P′ imparted to the cutting blade assembly, and the other main blade section 3A will be stripped off at the welds W. Also, deformation will occur on this part. On the other hand, no stripping at the welds W occur when the arrangement shown in Figs. 1a, 1b, 6 and 7 is employed. When the angle α is α = 90°, it is preferable to employ an arrangement as shown in Fig. 5.
A second embodiment shown in Figs. 2a and 2b corresponds to the prior art example shown in Fig. 12a. The integrated cutting blade assembly shown in Figs. 2a and 2b is intended to cut a plurality of sheet members having shapes substantially the same as those of sheet members cut by the cutting blades 2A to 2E shown in Fig. 12a. It will be apparent from Fig. 2a that common blade sections 4C, 4D, 4E and 4G are disposed inside of main blade sections 4A, 4B and 4F, and the former are welded to the latter at welds W as shown in Fig. 2b. The integral formation of such a plurality of cutting blades provides a sufficient mechanical strength from the structural aspect, so that the plywood board 6 shown in Fig. 12b is unnecessary. When reinforcement is desired, pipes 7A and 7B may be welded to the back side of the integrated cutting blade assembly to increase the mechanical strength as shown in Fig. 3, and another pipe 7C may also be welded in a relation orthogonal with respect to the pipes 7A and 7B as also shown in Fig. 3, so that the integrated cutting blade assembly can be carried by the bend. Other blade sections, for example, blade sections 4I and 4J may be additionally provided.
As shown in Figs. 3 and 4, a plurality of magnets 8A and 8B are preferably fixed to the integrated cutting blade assembly so that the integrated cutting blade assembly can be fixedly mounted on the table 5 of the press utilizing the magnetic force of these magnets. In another case (not shown), the integrated cutting blade assembly may be mounted on the upper plate of the press.
It is needless to mention that the sheet-member engaging end of the cutting blade is to be finished to have a sharp edge. The sharp edge may be tapered toward one side as shown in Fig. 9 or may be located intermediate the thickness of the cutting blade as shown in Fig. 10a.
In the case shown in Fig. 10a, the relation between the distance a from the sharp edge to one of the side faces of the cutting blade and the distance b from the sharp edge to the other side face of the cutting blade is preferably selected to be a> b. Numerically expressing, the values of a and b are preferably selected to be a = 2.7 mm and b = 0.5 mm. By so selecting the values of a and b, the useful service life of the cutting edge engaged by the press table of steel can be extended beyond that of the cutting edge shown in Fig. 9. In the case of the arrangement shown in Fig. 5, the relation between a and b of the cutting edge of the blade section 4E is preferably a = b. When the cutting edge shown in Fig. 10a is employed, and the joint between the blade sections has an arrangement as shown in Fig. 6, it is preferable to suitably remove the lower portion of the common blade section 3B until the resultant cutting edge makes intimate contact with the edges of the bent main blade sections 3A.
The present invention described above provides the following advantages:

a) Elimination of the gaps t between the cutting blades improves the rate of utilization of sheet materials to be cut.
b) Saving of the labor required for juxtaposition of separate cutting blades on a table of a press minimizes the period of time required for preparation for cutting sheet members.
c) When compared with the prior art cutting blade assembly shown in Fig. 12b, the plywood board is unnecessary, and the weight of the cutting blade assembly is lighter thereby decreasing the period of time required for preparation for the cutting operation.
d) The use of common blade sections connecting adjacent main blade sections can decrease the total weight of the cutting blade assembly.

Claims

1. An integrated cutting blade assembly for cutting sheet members, comprising a plurality of main blade sections and a plurality of common blade sections, said main blade sections being integrally welded to adjacent ones of said common blade sections to form a plurality of cutting blades.

2. An integrated cutting blade assembly according to claim 1, wherein, when the angle defined between the adjacent main blade sections forming a welded joint with one of said common blade sections is smaller than 90°, said adjacent main blade sections are formed by bending a web of steel, and said common blade section is welded to the bend of said main blade sections.

3. An integrated cutting blade assembly according to claim 1 or 2, wherein the edge of said blade sections has a sharp profile on one side only of its sectional shape.

4. An integrated cutting blade assembly according to claim 1 or 2, wherein the edge of said blade sections has a sharp profile in the middle of its thickness.

5. An integrated cutting blade assembly according to claim 4, wherein said common blade section welded to said main blade sections bent to form said welded joint has its lower portion removed until the edge of said common blade section makes intimate contact with the edges of said bent main blade sections.

6. An integrated cutting blade assembly according to any one of claims 1 to 5, wherein pipes are welded to the back side of said assembly.

7. An integrated cutting blade assembly according to claim 6, wherein another pipe extending orthogonal with respect to said pipes is further welded to the back side of said assembly.

8. An integrated cutting blade assembly according to any one of claims 1 to 7, wherein magnets are mounted on the back side of said assembly so that said assembly can be fixed to a table of a press by the magnetic force of said magnets.

9. An integrated cutting blade assembly according to any one of claims 1 to 7, wherein said assembly is mounted on an upper plate of a press.