Accessory locking device for a doorknob having a keyhole therein
US4631938A · kind A · utility
Inventor
Key dates
| Filing date | Jun 17, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Jun 17, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/7977
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The accessory locking device including hingedly connected shells having confrontable flanges that have convexly curved outer surface portions, each flange having a notch therein. A keeper tube has a slot so that the keeper tube is longitudinally slidable over the convexly curved portions of said flanges. Secured to the keeper tube is an auxiliary cylindrical lock having a projectable and retractable bolt, said bolt being projectable through a hole in the keeper tube so as to provide obstructive interference with the notches in said flanges. In this way, the keeper tube cannot be slidably withdrawn from the flanges until the bolt is fully retracted from the notches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.