# US 5,342,002 A · Magnetic tape cassette and method for manufacturing magnetic tape cassette

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- Number: US 5,342,002 A
- Document ID: US5342002A
- Status: Granted
- Kind: A
- Application number: 07/984,779
- Filed: 1992-12-03
- Granted: 1994-08-30
- Earliest claimed: 1991-04-17
- Assignees: Fuji Photo Film Co., Ltd.
- Inventors: Kiyoo Morita
- Web page: https://patentgrep.com/patent/US5342002A

## CPC

- B29C 45/1635: {using displaceable mould parts, e.g. retractable partition between adjacent mould cavities}
- G11B 23/08785: {Envelopes}
- G11B 23/113: Apparatus or processes specially adapted for the manufacture of magazines or cassettes {, e.g. initial loading into container (processes involving a single technical art and for which provision exists elsewhere, see the relevant class, e.g. B21, B29, B65)}
- 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)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A magnetic tape cassette and a method for manufacturing a magnetic tape cassette including a combination of upper and lower half cases each including a window part and a main body half, the main body half including a trapezoidal portion on a top side of the main body half extending along a length thereof and defining a portion of the cassette having an increased thickness. The cassette is produced in accordance with a process including the steps of providing a mold having a first injection space defining the main body half and a second injection space defining the window part, providing a first gate, communicating with the first injection space, in the metal mold at a position of the trapezoidal portion of the main body half, injecting a first resin into the first injection space through the first valve gate, providing a second valve gate, communicating with the second injection space, in the metal mold, and injecting a second resin into the second injection space through the second valve gate. The first gate is positioned centrally along the length of the trapezoidal space and the first and second resins have different colors.

## Claims

### Claim 1

A magnetic tape cassette including a combination of upper and lower half cases each including a window part and a main body half, said main body half including a trapezoidal portion on a top side of said main body half extending along a length thereof and defining a portion of said cassette having an increased thickness relative to said main body half, said magnetic tape cassette being manufactured by the method comprising the steps of:
providing a mold having a first injection space defining said main body half and a second injection space defining said window part;
providing a first valve gate communicating with said first injection space in said mold at a position of said trapezoidal portion of said main body half;
injecting a first resin into said first injection space through said first valve gate, said first valve gate leaving a gate mark in said trapezoidal portion;
providing a second valve gate communicating with said second injection space in said mold at a position corresponding to the position of the window part; and
injecting a second resin into said second injection space through said second valve gate, said second valve gate leaving a gate mark in said window part,
wherein said gate marks left by said first and second valve gates have no projections, and portions of said main body half and said window part adjacent said gate marks are consistent in color with other portions of said main body half and said window part.

### Claim 2 (depends on 1)

The magnetic tape cassette of claim 1, wherein said step of providing said first gate comprises positioning said first gate centrally along the length of said trapezoidal portion.

### Claim 3 (depends on 2)

The magnetic tape cassette of claim 2, wherein said injecting steps comprises injecting resins having different colors.

### Claim 4

A magnetic tape cassette including a combination of upper and lower half cases each including a window part and a main body half, said main body half including a trapezoidal portion on a top side of said main body half extending along a length thereof and defining a portion of said cassette having an increased thickness relative to said main body half, said magnetic tape cassette being manufactured by the method comprising the steps of:
providing a mold having a first injection space defining said main body half and a second injection space defining said window part;
providing a first valve gate communicating with said first injection space in said mold at a position of said trapezoidal portion of said main body half;
projecting a slide core into said second injection space;
injecting a first resin into said first injection space through said first valve gate, said first valve gate leaving a gate mark in said trapezoidal portion;
closing said first gate and allowing said first resin to harden;
providing a second valve gate communicating with said second injection space in said mold at a position corresponding to the position of the window part;
removing said slide core from said second injection space; and
injecting a second resin into said second injection space through said second valve gate, said second valve gate leaving a gate mark in said window part,
wherein said gate marks left by said first and second valve gates have no projections, and portion of said main body half and said window part adjacent said gate marks are consistent in color with other portions of said main body half and said window part.

### Claim 5 (depends on 4)

The magnetic tape cassette of claim 4, wherein said step or providing said first gate comprises positioning said first gate centrally along the length of said trapezoidal portion.

### Claim 6 (depends on 5)

The magnetic tape cassette of claim 5, wherein said injecting steps comprises injecting resins having different colors.

### Claim 7

A magnetic tape cassette containing magnetic tape wound around a pair of reels which are rotatably provided in said cassette, said cassette comprising a combination of upper and lower half cases each including a window part and a half main body part, wherein:
said half main body part is formed of a first resin injected through a first valve gate into a first injection space in a mold, said valve gate being communicated with said first injection space corresponding to a position on a trapezoidal portion of said half main body part having an increased thickness relative to said half main body part, said first valve gate leaving a gate mark in said trapezoidal portion;
said window part is formed of a second resin injected through a second valve gate into a second injection space in the mold, said second valve gate being communicated with said second injection space corresponding to the position of the window part, said second valve gate leaving a gate mark in said window part; and
the molding of said half main body part is conducted before that of said window part, and wherein said gate marks left by said first and second valve gates have no projections, and portions of said half main body part and said window part adjacent said gate marks are consistent in color with other portions of said half main body part and said window part.

### Claim 8 (depends on 7)

A magnetic tape cassette as recited in claim 7, wherein said half main body part is formed of said first resin injected through said first valve gate positioning centrally along the length of said trapezoidal portion.

### Claim 9 (depends on 7)

A magnetic tape cassette as recited in claim 7, wherein said parts are both formed of resins having different colors.