# US 4,981,061 A · Steel rule die and method of manufacture

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- Number: US 4,981,061 A
- Document ID: US4981061A
- Status: Granted
- Kind: A
- Application number: 07/347,572
- Filed: 1989-05-05
- Granted: 1991-01-01
- Earliest claimed: 1989-05-05
- Inventors: Ronald A. Hillock; Steven B. Ross
- Web page: https://patentgrep.com/patent/US4981061A

## CPC

- B23P 15/406: {rotary or plane die cutters}
- B21D 37/205: {Making cutting tools}
- B26F 1/44: Cutters therefor; Dies therefor
- B26F 1/384: {using rotating drums}
- B26F 2001/4463: {Methods and devices for rule setting, fixation, preparing cutting dies}
- B29C 2793/0036: Slitting
- Y10S 76/06: Laminated
- Y10T 83/9454: Reciprocable type
- Y10T 83/97: Miscellaneous
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F)
- B26F: PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING (marking-out, perforating or making buttonholes A41H25/00; shoemaking A43D; surgery A61B; punching metal B21D; drilling metal B23B; cutting of metal by applying heat locally, e.g. flame cutting, B23K; cutting by abrasive fluid jets B24C5/02; details common to machines for severing B26D; drilling wood B27C; drilling stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; of glass C03B; of leather C14B; of textile materials D06H; for light guides G02B6/25; of tickets G07B)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A steel rule die is disclosed having strengthening layers bonded to the die board to stiffen the die board against flexing during handling, while alleviating the tendency to loosen the steel rule during handling and enhancing the durability of the die. KEVLAR graphite fiber fabric is impregnated and bonded to either face of the die board with epoxy resin.

## Claims

### Claim 1

A flat bed steel rule die comprising a flat plywood sheet having opposite faces and formed with a slot pattern extending in a pattern corresponding to a part to be die cut, a steel rule piece extending in a shape corresponding to said pattern, said steel rule piece fit into said slot pattern, said die characterized by a stiffening lamination bonded to each opposite face of said plywood sheet composed of at least one layer of graphite fiber fabric bonded to each opposite face of said plywood sheet to form a stiffened die board.

### Claim 2 (depends on 1)

The steel rule die according to claim 1 further including a series of said fabric layers bonded on each opposite face of said plywood sheet.

### Claim 3 (depends on 2)

The steel rule die according to claim 2 further including coatings of epoxy resin bonding each series of said fabric layers to each other and a respective opposite face of said plywood sheet.

### Claim 4 (depends on 3)

The steel rule die according to claim 3 wherein said epoxy coatings impregnate said fabric layers.

### Claim 5 (depends on 4)

The steel rule die according to claim 4 wherein said graphite fiber fabric layers comprise KELVAR (.TM. ) material.

### Claim 6 (depends on 3)

The steel rule die according to claim 3 further including a bead of epoxy resin applied to the rule along either side of the slot in said die board.

### Claim 7

A method of making a flat bed durable steel rule die including the steps of:
constructing a high stiffness die board by bonding high tensile strength fiber fabric layers to each face of a flat sheet of plywood;
cutting a slot pattern in said high stiffness die board in the form of the part to be cut by said die;
forming a rule piece in the shape of said slot pattern;
assembling said rule piece into said slot pattern.

### Claim 8 (depends on 7)

The method according to claim 7 wherein said fabric layers are bonded by applying coats of epoxy resin to said fabric layers.

### Claim 9 (depends on 7)

The method according to claim 7 wherein said coatings of epoxy resin, fabric layers and die board are compressed in a press during curing of said epoxy resins to impregnate said fabric layer with epoxy resin.