Drum brakes with interconneted multi-degrees-of-freedom shoes

Abstract

This invention is a new type of drum brake and its variants for motor vehicles, the shoe mechanism assembly of which has at least one set of interconnected shoe mechanism and automatic adjusting mechanism of brake clearance. The interconnected shoe mechanism consists of two interconnected composite shoes of multiple degrees of freedom. Each composite shoe consists of a shoe and a driving lever. The shoe is jointed to the driving lever with a cylindrical pin or a elliptical pin matching with a cylindrical hole or a spherical joint, and the driving lever is pivoted on the backplate of brake with a cylindrical pin or a elliptical pin matching with a cylindrical hole or a spherical joint. The automatic clearance adjusting mechanism is fixed on the backplate and interconnected with the driving lever. When the brake is applied, the automatic clearance adjusting mechanism works as the driving lever drives the shoe outwards against the drum to maintain the required clearance between the drum and lining if lining wear occurs. This type of drum brake and its variants have excellent braking performance in capacity and stability owing to its uniform pressure distribution over the friction surfaces between drum and linings, better resistance to capacity fade with decreasing coefficient of friction due to increasing temperature or humidity, longer life span of shoes, uniform and constant clearance between drum and linings, as well as high shoe factor. They offer the better prospects of solution of existing problems in the vehicle drum brakes.

Dependencies are inferred from the claim text.