Fork lift truck speed control dependent upon fork elevation
US4265337A · kind A · utility
33Cited by
7References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Jul 16, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66F17/003
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A speed control circuit is provided for a lift truck which is driven by an electric truck drive motor powered from a power source through a motor controller. The motor controller is responsive to a power control signal generated by summing a speed sensor signal, which is derived by comparing a tachometer signal with a speed selection signal. A fork height sensor provides a fork height signal which is used to limit the maximum level of the speed control signal. A safety circuit monitors operation of the speed control circuit and disconnects the circuit from the motor controller upon occurrence of a malfunction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.