| 摘要 |
<p>A trailer brake system provides an improved disc brake assembly (15) with a caliper unit (40) having first and second housings (42, 43) which contain hydraulically operated opposed pistons (46, 46') for engaging brake pads (48, 50) and providing relative movement toward and away from a brake rotor (29). The caliper unit (40) is pivotally mounted to the stationary mounting bracket (30) to allow for movement of the caliper unit (40) for opening a relief valve (70) and release of the hydraulic pressure and firm braking engagement of the brake pads (48, 50) during the backing, non-braking mode. The dual piston arrangement (46, 46') provides for self-centering/self-adjustment of the brake pads (48, 50) without the need for in and out axial movement of the caliper unit (40). The first and second housings (42, 43) also include internal passageways (54) passing therebetween for delivering a high pressure hydraulic fluid to the first and second cylinders (44, 44'), the fluid providing simultaneous actuation of the opposed pistons (46, 46'). An opening (56) is provided in the top of the caliper unit (40) for accessing the brake pads (48, 50). The brake pads (48, 50) may be visually inspected, installed and removed through the opening (56), and heat is allowed to dissipate from the brake pads (48, 50) through the opening (56) during operation. One end of the stationary mounting bracket (30) is left open (31) so that it may be placed over the axle of the trailer and installed without the need for removing the entire hub assembly. A leaf spring (34) is provided for biasing the caliper unit (40) to hold the relief valve (70) closed and towards a forward position during forward movement of the trailer in readiness for brake operation.</p> |
