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:
Sep. 25, 1979
Filed:
Jun. 16, 1977
Otto Mueller, Jr, Detroit, MI (US);
Massey-Ferguson Inc., Detroit, MI (US);
Abstract
An improved pressure control valve which provides equal damping force in both directions of movement of the valve spool and which also provides negative feedback to partially negate fast transients leading to valve instability. The pressure control valve includes a valve body having an inlet chamber and an enlarged adjacent damping chamber. A valve spool is received within the chambers, the spool having a first portion and a second radially outwardly extending portion adjacent the first portion and disposed within the damping chamber. As the valve spool is shifted to an open position fluid will be expelled from the damping chamber through a first orifice, and as the valve spool returns towards its closed position fluid will be expelled through a second orifice, the orifices having cross-sectional areas proportionate to the volume of fluid being expelled so that equal damping will be obtained in either direction of movement of the valve spool. The valve spool is provided with an orifice passageway which permits fluid in the inlet chamber to be in communication with fluid in the damping chamber whereby transient peaks in the inlet may be transmitted to the damping chamber to provide for negative feedback.