The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 03, 1981
Filed:
Sep. 25, 1978
William J Spivey, Jr, Joliet, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A control circuit comprises pressurized fluid source (11), a two-position directional control valve (14) and an actuator (13), such as the pump of a hydrostatic transmission, connected to the fluid source and the control valve to be selectively actuated thereby. Relay valves (17, 18, 19) are interconnected in the control circuit to sequentially (A) prevent communication of pressurized fluid from the source to the actuator upon activation of the source and when the control valve is maintained in its first position, (B) communicate pressurized fluid from the source to the actuator upon continued activation of the source and when the control valve is moved from its first position to a second position thereof, and (C) prevent communication of pressurized fluid from the source to the actuator when the source is deactivated and then reactivated with the control valve being maintained in its second position whereby the control valve must be first returned to its first position and then moved to its second position before pressurized fluid can be communicated to the actuator for actuation thereof.