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:
Jan. 11, 2000
Filed:
Aug. 20, 1997
William J Hicks, Muskegon, MI (US);
Neway Anchorlok International, Inc., Muskegon, MI (US);
Abstract
A spring brake actuator (14) includes a housing having first (51) and second (52) housing sections defining a housing interior (53). A support plate (70) is movable between retracted and extended positions relative to the housing and a spring (72) is disposed between the second housing section and a first surface of the support plate for biasing the support plate to the extended position. An actuator rod (60) is operably connected to the support plate (70) at a first end for reciprocal movement with the support plate. Another end of the actuator rod extends through an aperture (64) in the first housing section (51). A flexible diaphragm (358) abuts a second surface of the support plate opposite the first surface and divides the interior of the housing into a first chamber and a second chamber. A surface of the diaphragm is exposed to fluid pressure to thereby force the support plate (70) to the retracted position against the bias of the spring (72). The diaphragm includes an elongate portion that forms a loop (360) when the support plate is in the retracted position to thereby increase the effective surface area over which the fluid pressure acts as the support plate (70) moves from the extended position to the retracted position. A service brake actuator (12) may be in tandem with the spring brake actuator (14). The service brake actuator includes a housing and a second movable diaphragm within the housing that divides the interior of the housing into first and second service brake chambers. The diaphragm (132) has an elongate portion that forms a loop when a push rod (18) in the service brake actuator housing is in the extended position to increase the effective surface area over which the fluid pressure acts as the push rod (18) moves from the retracted position to the extended position and thereby increase the braking force of the service brake actuator.