Indian Head Industries, Inc.

Thomas O Schultz

Ronald S Plantan

Christopher J Prager

Michael M Holm

Gary R Sprague

An improved diaphragm-type pneumatic brake actuator wherein the diaphragm is releasably secured to the piston as the diaphragm is inverted during actuation of the braking system of a vehicle thereby reducing wear of the flexible diaphragm and improving the performance of the brake actuator. In the disclosed embodiment, a rib or lip is formed on the surface of the diaphragm which receives the periphery of the piston as the diaphragm is inverted forming a mechanical interlock between the diaphragm and the piston thereby preventing spacing of the contact surface of the piston and the central portion of the diaphragm and frictional wear between the peripheral edge of the piston and the diaphragm. In the preferred embodiment, the piston includes an arcuate rim which extends away from the central portion of the diaphragm when the diaphragm is located in its extended cup-shaped position prior to actuation of the vehicle braking system and the diaphragm then conforms to the arcuate rim as the diaphragm is inverted and the diaphragm rib snaps over the piston rim as the diaphragm is inverted to actuate the vehicle braking system. The diaphragm rib may be molded on the surface of the diaphragm when the diaphragm is molded without any substantial increase in cost.

Brake actuator

A brake actuator having an improved push rod and end plate assembly which eliminates the requirement for thread adhesive and avoids deformation of the exterior surface of the push rod. The push rod includes an axial internally threaded bore through one end and the shank portion of the mounting screw includes an unthreaded intermediate portion adjacent the threaded end portion having a plurality of radial lobes which are turned into the internally threaded bore of the push rod securely retaining the end plate to the push rod under vibration loading and extreme temperature conditions. The radial lobes on the intermediate portion of the mounting screw each include an arcuate spiral lead surface and a flat generally radial following surface which requires only a relatively small torque to secure the end plate to the push rod, but a significantly larger torque to unthread the mounting screw from the push rod.

Push rod and plate assembly for brake actuators and method of forming same

A shield for a brake actuator has a bore closely surrounding a piston rod which is welded to a yoke. The shield is formed with a plurality of slits that allow portions of the shield between the slits to bend radially outwardly and allow the yoke to move through the bore. Thus, the invention allows the use of a yoke which is welded to a piston rod, and also allows the use of a shield which closely surrounds the piston rod.

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Davidson, NC, United States of America

Thomas O Schultz