Method for molding plastic shutter for magnetic disk cartridge
US5472657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1994 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Jul 28, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/40
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In a method for injection molding a plastic shutter for a magnetic disk cartridge, the shutter having windows corresponding to an opening formed in a magnetic disk cartridge and being substantially U-shaped in section, the diameter of an injection cylinder for injecting molten resin for forming the shutter is determined according to the following equation: EQU D.sup.2 =A.times.C.times.M / .pi. where D is the diameter (mm) of the injection cylinder, C is the number of the plastic shutters molded simultaneously with one metal mold, M is the volume (cm.sup.3) of the plastic shutter, and A is the cylinder coefficient of the injection cylinder and is limited as follows: EQU 130.ltoreq.A.ltoreq.510. The inventive method is considerably stable, being free from the difficulties that short shot occurs with the metal mold, and the resultant shutter is deformed near the gate of the metal mold, or bent in its entirety.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.