Boom gate
US4035955A · kind A · utility
Inventor
Key dates
| Filing date | Mar 14, 1975 |
| Grant date | Jul 19, 1977 |
| Priority date | — |
| Expiry date | Mar 14, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE01F13/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A boom gate comprises a first-class lever counterweighted at one end adjacent to which is the lever fulcrum. The fulcrum is displaceable lengthwise of the lever through a short distance sufficient to cross the center of gravity of the lever. This movement is controlled by a mechanism and the boom lifts automatically under its own weight when the center of gravity is passed. The advantage of such a system is that the effort required to raise the boom is very little and the use of high-torque equipment is unnecessary so that the boom gate can be cheaply made. Ways of displacing the fulcrum using pneumatic pressure, a handle or an electric motor are described. Also a double-sided boom gate is described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.