Clyde Laverne Pritchard
Engineers at Riverdale Rd, Sioux Falls, SD
License number
Colorado 10155
Issued Date
Sep 26, 1970
Renew Date
Feb 23, 1985
Expiration Date
Feb 23, 1985
Type
Professional Engineer
Address
Address
1600 Riverdale Rd, Sioux Falls, SD 57105
Professional information
Automatic Hydraulic Series-Parallel Shift Device For Implement
US Patent:
4129258, Dec 12, 1978
Filed:
Jan 31, 1977
Appl. No.:
5/764444
Inventors:
Richard H. Mott - Sioux Falls SD
Clyde L. Pritchard - Sioux Falls SD
Clyde L. Pritchard - Sioux Falls SD
Assignee:
Du-Al Manufacturing Company - Sioux Falls SD
International Classification:
A01C 306
US Classification:
239650
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.