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:
Jul. 02, 1991
Filed:
Sep. 01, 1989
Harold Gold, Shaker Heights, OH (US);
Other;
Abstract
Two and three stage servovalves having a first stage comprising a torque-motor driven, double jet, flapper valve, extend the present art in dynamic response through the replacement of the present flapper valve inlet orifices with active flow controllers. The flow controllers hold the flow rate from the pressure supply substantially constant under varying supply pressure and under varying operating conditions of the flapper valve and of the second and third stages. The flow controllers increase the gain of differential pressure to flapper displacement, through which the flapper to nozzle null gap can be reduced which, in turn, further increases the gain of differential pressure to flapper displacement and reduces the total flapper stroke. The stroke reduction reduces the torque-motor centering spring force, through which the torque-motor limited differential pressure can be increased. These factors significantly extend the operating supply pressure range and extend the frequency band of second and third stages of multistage servovalves.