Door safety circuit for monitoring of story doors in lift installations
US5616895A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1994 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Oct 5, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B13/22
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A door safety circuit for monitoring of story doors in lift installations. The door safety circuit includes a transmitter that produces a non-electrical signal which is guided by a series of conductor portions. The non-electrical signal may be transmitted through a first conductor partial portion to a latching device of a first story door, depending upon the latched state of the first story door, the signal may be either transmitted to a second conductor partial portion, which may be included within the latching device, or no longer transmitted. If the signal is similarly transmitted through a plurality of conductor partial portions and serially connected story door latching devices, the circuit may indicate that each story door is properly latched. The circuit may also include a plurality of sensors coupled to a failure recognition circuit for monitoring each conductor partial portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.