One piece knock-out plug
US3991446A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1975 |
| Grant date | Nov 16, 1976 |
| Priority date | — |
| Expiry date | Apr 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02G3/083
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A closure or bushing member for openings in electrical boxes, conduit ends and the like is formed as an integral unit of a thermoplastic synthetic organic polymeric resin and includes a disc or annular shaped head and a coaxial hollow cylindrical shank of lesser diameter. Extending from opposite sides of the distal end of the shank are a pair of opposite radially projecting arms, which terminate in wing members of greater width than the radial arms and which have conically surfaced outer faces flaring rearwardly outwardly. A peripheral recess is formed in the rear outer face of each wing to provide a rearwardly facing shoulder for resiliently engaging the inside border of the opening to which the closure member is applied to retain the closure member therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.