Apparatus for indicating incomplete and complete fastening of screw components
US4988246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1990 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Feb 23, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S116/34
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Apparatus for indicating incomplete and complete fastening of a screw includes a washer and a ring of a generally flat synthetic resin sheet. The washer includes a pair of washer portions of a generally flat, round shape and a joint portion interconnecting the washer portions to face them in opposite directions to enable the washer portions to receive a shank of a screw in the openings thereof. The lengthwise section of the joint portion forms generally a U shape. The ring is made of a generally round, deformable material and is inserted between the pair of washer portions thus facing each other. The deformable material is expanded radially outward, when compressed by the washer portions receiving the shank of the screw when fastened. Upon the compressive force reaching a predetermined value, the ring will be broken due to the pair of washer portions overlaying one another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.