Overhead impact sensing system
US4979588A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1990 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Feb 12, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66F17/006
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
An electrical deactivation circuit and a two piece overhead guard assembly including two separately movable bar members which extends upward and over the head of an operator located on the upper work platform of an aerial work platform. The guard bar members are connected to the frame of the upper work platform by a pair of movable support assemblies, the movement of which actuates impact detection induction type proximity switch means to interrupt electrical power applied to the electrical control circuits and stop the engine powering the aerial work platform. Each movable support assembly includes a pair of spring loaded mechanical subassemblies including a pair of clamp members between which is located an elongated coil spring whose stiffness is varied in accordance with the distance separation of the clamps. An inductive type proximity switch is located in the lower end portion of each spring to sense movement of the inner end of a respective guard bar member. Each proximity switch is connected in an electrial circuit having a built in time delay or lock out feature for applying power to the aerial work platform after a predetermined time delay and thereafter interrupting power…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.