Abstract: Methods and corresponding control devices for releasing an electric actuator in a reliable manner, such as an electric parking brake in particular, in a motor vehicle brake system. The aim of the invention is to provide an improved function and architecture which helps prevent the disadvantages of open-loop control systems when using a rationalized sensor system, thereby obviating closed-loop control systems. This is achieved by a release method and a corresponding electronic control unit which obtains an especially modulated change in the power requirement during the release process upon impacting the quasi-elastic release end stop of the electric actuating unit such that the change is fed back, the change being detected in order to be used as information for a power interruption or a termination of the power supply to the electric actuating unit.

Abstract: Methods and corresponding control devices for releasing an electric actuator in a reliable manner, such as an electric parking brake in particular, in a motor vehicle brake system. The aim of the invention is to provide an improved function and architecture which helps prevent the disadvantages of open-loop control systems when using a rationalized sensor system, thereby obviating closed-loop control systems. This is achieved by a release method and a corresponding electronic control unit which obtains an especially modulated change in the power requirement during the release process upon impacting the quasi-elastic release end stop of the electric actuating unit such that the change is fed back, the change being detected in order to be used as information for a power interruption or a termination of the power supply to the electric actuating unit.

Abstract: A parking brake is described which has a backplate, first and second brake shoe portions mounted on the backplate, a drum encircling the brake shoe portions, a parking lever pivoted adjacent one end on one of the brake shoe portions, and a strut extending between a first abutment on the parking lever and a second abutment on the other of the brake shoe portions. The backplate includes a viewing opening, and the parking lever and the one brake shoe portion include datum surfaces visible through the viewing opening from which the position of the parking lever relative to the brake shoe portion can be assessed.

Abstract: A parking brake (10) having a drum containing first and second brake shoe portions (11, 12), a handbrake lever (18) pivoted (19) adjacent one end on one (11) of the brake shoe portions and a strut (20) extending between a first abutment on the handbrake lever and a second abutment (21) on the other (12) of the brake shoe portions. Pivoting of the handbrake lever relative to said one brake shoe portion (11) moves the strut (20) which in turn moves the other brake shoe portion (12) away from said one brake shoe portion to bring the shoe portions into contact with the drum thus applying the parking brake. One of the abutments is in the form of a biased wedging means (21) which acts on the strut (20) to take up all play in the thrust path between the handbrake lever (18) and the other brake shoe portion (12) via the strut.

Abstract: A cable operated drum brake has an internal brake operating lever with a quick-attach device for an operating cable. A cable attachment tube projects from a backplate of the brake and the operating cable has an inner cable with a latching formation on the end thereof and a cable outer sleeve. An end portion of the operating cable is slideable towards the backplate within the tube up to a first position at which further movement towards the backplate is stopped by contact between an abutment on the tube and a cooperating abutment on the cable outer sleeve. When the latching formation has moved past the quick-attach device, the cable is then subsequently moveable away from the backplate within the tube to a second position in which the latching formation is fully engaged with the quick-attach device. A fastener maintains the latching formation engaged with the quick-attach device during subsequent operation.

Abstract: A parking brake is described which has a backplate (13), first and second brake shoe portions (11,12) mounted on the backplate, a drum encircling the brake shoe portions, a parking lever (15) pivoted (21) adjacent one end on one (12) of the brake shoe portions, and a strut (17) extending between a first abutment on the parking lever (15) and a second abutment on the other (11) of the brake shoe portions. Operation of a driver operated handbrake lever pivots the parking lever relative to said one brake shoe portion (12)via a connecting cable (19) so that the parking lever moves from a retracted position to an operative position thus moving the strut (17) which in turn moves the other brake shoe portion (11) away from said one brake shoe portion (12) to bring the shoe portions into contact with the drum thus apply the parking brake.

Abstract: A cable operated drum brake has an internal brake operating lever (12) provided with an quick-attach device (10) for an operating cable (11). A cable attachment tube (21) projects from a backplate (17) of the brake and the operating cable has a cable inner (13) with a latching formation (14) on the end thereof and a cable outer sleeve (15). An end portion of the operating cable is slideable towards (X) the backplate (17) within the tube (21) up to a first position at which further movement towards the backplate is stopped by contact between an abutment (26) on the tube and a cooperating abutment (31a) on the cable outer sleeve. When in the first position the latching formation (14) has moved passed the quick-attach device (10). The cable is then subsequently moveable away from the backplate (Y) within the tube to a second position in which the latching formation (14) on the cable inner is fully engaged with the quick-attach device (10).

Abstract: A parking brake (10) having a drum containing first and second brake shoe portions (11, 12), a handbrake lever (18) pivoted (19) adjacent one end on one (11) of the brake shoe portions and a strut (20) extending between a first abutment on the handbrake lever and a second abutment (21) on the other (12) of the brake shoe portions. Pivoting of the handbrake lever relative to said one brake shoe portion (11) moves the strut (20) which in turn moves the other brake shoe portion (12) away from said one brake shoe portion to bring the shoe portions into contact with the drum thus applying the parking brake. One of the abutments is in the form of a biased wedging means (21) which acts on the strut (20) to take up all play in the thrust path between the handbrake lever (18) and the other brake shoe portion (12) via the strut.

Abstract: A brake adjuster for adjusting the working clearance of the shoes of an automotive drum brake, the adjuster including three co-axial elements a first rod element (25) having a head portion for engagement with a first brake shoe and a threaded stem portion, an intermediate element (28) in threaded engagement with the first rod element and a second rod element (27) having a head portion for engagement with a second brake shoe and a stem portion slideably connected with the intermediate element (28) and free to rotate relative thereto. A reaction member (30) is mounted on the intermediate element (28) and a ring gear (35) is provided on the intermediate element which is axially located between the second rod element and the reaction member. A leaf spring (31) acts between the second rod element (27) and the reaction member (30) for pushing the second rod element away from the intermediate element (28).

Abstract: A brake adjuster for adjusting the working clearance of the shoes of an automotive drum brake, the adjuster including three co-axial elements a first rod element (25) having a head portion for engagement with a first brake shoe and a threaded stem portion, an intermediate element (28) in threaded engagement with the first rod element and a second rod element (27) having a head portion for engagement with a second brake shoe and a stem portion slideably connected with the intermediate element (28) and free to rotate relative thereto. A reaction member (30) is mounted on the intermediate element (28) and a ring gear (35) is provided on the intermediate element which is axially located between the second rod element and the reaction member. A leaf spring (31) acts between the second rod element (27) and the reaction member (30) for pushing the second rod element away from the intermediate element (28).

Abstract: A brake adjuster comprises a variable length strut (16) having two end portions (30, 31) and an intermediate portion (32) therebetween which is in screw threaded engagement with one of the end portions (31). A pawl (39) is attached to the other end portion (30) and engages an array of ratchet teeth (38) the intermediate portion (32). As the end portions of the strut (30, 31) move apart during a brake application the pawl (39) rides up a flank of a ratchet tooth (38a) and if the movement apart exceeds a predetermined amount engages behind the tooth (38a). When the end portions (30, 31) move towards each other in the next brake disengagement, the intermediate portion (32) is rotated relative to said one of the end portions (31) to increase the effective length of the strut (16). The pawl (39) may be bi-metallic and arranged to disengage the ratchet teeth (38) if the temperature of the adjuster rises above a predetermined level.