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:
Apr. 03, 1979
Filed:
Feb. 16, 1977
Leonard L Johnson, Fort Wayne, IN (US);
TECO, Inc., Fort Wayne, IN (US);
Abstract
In an articulated boom having a platform and comprised of upper and lower booms respectively, there are hydraulic actuators controlling the movements of the upper and lower booms. Control means are necessary in association with the lower boom to control its rate of movement, slowing such rate of movement as the lower boom approaches its retracted, or full rest, position. A position responsive valve permits unimpeded fluid pressure access to the actuator for lowering the lower boom at its regular rate until the lower boom reaches a critical angle as it approaches horizontal position, at which time the valve prevents further fluid access to its associated hydraulic actuator. Thereafter, a position responsive valve and a pressure reducing valve reduce the rate of descent of the lower boom until the lower boom is fully retracted to its rest position. The described hydraulic control is in a single package which can be retrofitted into existing hydraulic systems and is independent of the pilot operated check valve and cylinder, being located between the main control valve and the power cylinder and does not interfere with existing hydraulic controls.