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:
May. 16, 1978
Filed:
Sep. 07, 1976
Leonard L Johnson, Fort Wayne, IN (US);
Teco, Inc., Fort Wayne, IN (US);
Abstract
A hydraulic valve system uses spool type pilot valves with the valve openings notched to provide non-linear response to movement of pilot valves. A servo type valve with a four-way spring centered spool is operated either manually or hydraulically by the spool pilot valve. A limit stop is located at each end of the servo spool valve. The notching geometry in the spools of both the pilot valve and servo valve provide a non-linear response such that controllability and safety are improved, without hysteresis. The system has a manual override on both ends of the servo valve which is operated independently of the pilot spool valve. The system is proposed for use on articulated aerial towers which consist of a mobile platform, a rotatable mounting for a lower boom, an upper boom having an articulated mounting on the lower boom, and personnel or tool carrying basket at the outer end of the upper boom.