Sequencing control circuit
US4119896A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1976 |
| Grant date | Oct 10, 1978 |
| Priority date | — |
| Expiry date | May 28, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/106
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A sequencing control circuit is provided for a door operator motor which is connected to open and close a garage door as controlled by signals from manual switches and load switches. The sequencing control circuit includes time delay means with a first time delay period in the order of six to eight seconds. This permits a person to hold a push button switch closed for about six to eight seconds so that a slab door may be opened against a snow drift which otherwise would have so much torque requirement on the motor that an overload switch would stop the motor. Enabling means is provided to enable the motor during this time period yet to disable the constant signal from the push button for periods longer than this time delay period so that the door operator motor then is responsive to signals from the load switches. The sequencing control circuit also includes a latch circuit having an output in a feed back loop to maintain the latch circuit latched upon a momentary input control signal. This allows time for the motor to accelerate the load to a normal running condition and to open any closed limit switch or closed torque switch during this acceleration period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.