Time delay for a seat switch activated loader boom lock
US4389154A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1981 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | May 13, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02F9/166
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A time delay device for the seat interlock mechanism on a skid-steer loader is disclosed wherein the boom structure will not be rendered inoperable for vertical movement, until the passage of a short predetermined period of time after the seat switch has indicated that the operator has left the loader seat. A solenoid valve is operable to stop the flow of fluid to the hydraulic cylinders moving the boom structure along a generally vertical path. A seat switch connected in the electrical circuit to the solenoid valve activates the solenoid valve to stop the fluid flow if the operator leaves the loader seat. The time delay device includes a capacitor, a resistor and a diode in series-parallel with both the source of electrical current and the solenoid valve and prevents the solenoid valve from restricting the flow of fluid through the hydraulic circuit to the boom lift cylinders for a short period of time after the seat switch has indicated that the operator has left the seat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.