Boundary plane warning system
US4408195A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Aug 17, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C15/045
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A laser transmitter emits a beam which scans about a scanning axis to effect a curtain of light which defines a boundary of a working space. Photosensors mounted on the outboard portion of a crane or other construction equipment generate warning signals to the construction equipment operator and other nearby personnel whenever these photosensors move into the light curtain. Additional curtain sensing equipment positioned to intercept the rotating laser beam with each cycle of rotation develops an alarm signal which activates an alarm horn and/or alarm light whenever the laser transmitter fails to provide the light curtain. The additional curtain sensing equipment is mounted an appropriate distance from the laser transmitter so that such additional sensing equipment will not interfere with the reception of the light curtain by the photosensors on the crane, and the laser transmitter and the additional curtain sensing equipment are mounted several feet above the ground to prevent foot traffic and vehicle traffic from producing false indications of a laser transmitter failure by intercepting the light curtain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.