Pneumatic tire pressure indicator
US3999503A · kind A · utility
Inventors
Key dates
| Filing date | Jan 9, 1976 |
| Grant date | Dec 28, 1976 |
| Priority date | — |
| Expiry date | Jan 9, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60C23/0496
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A pneumatic tire pressure indicator adapted to be attached to a valve stem of a pneumatic tire for designating a low pressure condition therein includes a member defining at least one window in a housing, and an attention-attracting member mounted on the housing out of proper orientation relative to the window to conceal the attention-attracting member from view when normal air pressure exists within the tire. A mechanism rotates the members relative to one another to properly orient them to expose the attention-attracting member through the window for indicating purposes when the tire pressure falls below a predetermined value. A sensing mechanism activates the rotating mechanism when the pressure within the pneumatic tire falls below the predetermined value. In one embodiment of the invention, the member defining at least one window and the attention-attracting member each includes optically polarized material which are normally oriented in a cross polarized manner to conceal the attention-attracting member from view, the members being rotated relative to one another to cause the attention-attracting member to be visible through the other polarized material serving as a window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.