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:
Dec. 12, 1978
Filed:
Jan. 31, 1977
Richard H Mott, Sioux Falls, SD (US);
Clyde L Pritchard, Sioux Falls, SD (US);
Du-Al Manufacturing Company, Sioux Falls, SD (US);
Abstract
An apparatus such as a farm implement or other mechanical device subject to varying loads and power requirements has an hydraulic circuit which automatically shifts two or more hydraulic motors from a normal series operation at high speed to a parallel operation at reduced speed but higher torque in response to increased fluid pressure upstream of the motors. In a disclosed embodiment, a valve is connected to block flows from the fluid source to inlet of one motor and from outlets of both motors directly to drain under low pressure conditions but to shift to allow two parallel flows to the two motors upon increase in pressure in the flow from the source. A third motor driving an auxiliary device such as a material feed is by-passed in the parallel-flow condition.