Abstract: A vehicle wheel drum brake assembly includes an improved brake actuator assembly having a stabilizing cam and roller design. The cam and roller include a centering and guiding surface that cooperate to prevent relative movement between the cam and the rollers in an axial direction which is generally perpendicular to a direction of movement of the brake shoes caused by the cam camming the rollers. The rollers and brake shoes are provided with similarly cooperating centering and guiding surfaces to prevent undesirable relative movement between the shoes and rollers. The centering and guiding surfaces include non-parallel sidewalls such that a wedge of surface contact is provided. The centering and guiding surfaces provide a centering feature and increase the amount of surface contact and the amount of desirable friction experienced in the system.

Abstract: An improved brake shoe table includes the edges of the brake shoe table being bent radially inwardly relative to the remainder of the table by between 45 and 90 degrees. The bent edges increase the rigidity of the brake shoe and also reduce localized lining wear by bringing the lining into contact with a brake drum in a more uniform fashion. Moreover, the improved brake shoe design has unexpectedly decreased the operation noise associated with the use of a cam brake system.