A brake cylinder device having a parking spring brake mechanism, provided with a clutch mechanism configured so as to transmit or block urging force of a piston to or from a brake force transmitting unit; a latch member for restricting displacement of the brake force transmitting unit relative to the piston by engaging with the clutch mechanism, and allowing displacement of the brake force transmitting unit relative to the piston by disengaging from the clutch mechanism; a latch lock member for engaging at an inclined part with a protruding part of the latch member; and a rotation-preventing part for preventing the latch lock member from rotating.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

To produce a combined service brake cylinder and spring-loaded brake cylinder for a vehicle brake system, force-actuation path characteristic curves of the brake system with the elements that can be actuated by a storage spring of the spring-loaded cylinder are measured/recorded under different operational conditions. Force-actuation characteristic curves of different storage springs for use in the spring-loaded cylinder are also measured/recorded. The minimum necessary actuation stroke of the piston of the spring-loaded cylinder and the minimum necessary spring force for a storage spring to effect a parking brake function are determined by the intersection of the force-actuation curves of the brake system with those of the storage springs. The storage spring that generates a sufficient actuation force under certain operating conditions and the dimensions resulting from the smallest possible piston actuation stroke are selected for producing the combined service brake cylinder and spring-loaded cylinder.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A control method for controlling a spring loaded brake actuator (9) comprising a first chamber (Ch1) to receive a parking brake pressure (PBR) acting against a main spring (92), and a second chamber (Ch2) to receive a service brake pressure (SB) for applying a service brake force, the method comprising a circumstantial selection of one control law among a set of control laws comprising two or more compound control laws:—where the first compound control law (CL1), known as anti-compound mode, is such the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a first upper limit (UL1) corresponding to the force of the main spring (92) when the parking brake pressure (PBR) is substantially null, —where the second compound control law (CL2), known as controlled-compound mode, is such that the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a second upper limit (UL2) higher than the first upper limit.

A spring brake actuator for a commercial vehicle includes a service brake portion (4) and a spring brake portion (6) that has a housing (8, 108) with a first end (10, 110) proximal to the service brake portion (4), a wall section (12, 112) extending from the first end (10, 110), a second end (14, 114) distal to the service brake portion (4), and a locking mechanism (16, 116) for locking the first and second ends (10, 110, 14, 114) to the wall section (12, 112). The locking mechanism (16, 116) is arranged between the wall section (12, 112) and the second end (14, 114) of the housing (8, 108).

An interface between an adapter push rod and a parking brake diaphragm seal includes an axial projection at one end of the push rod, a thread extending axially between a free end of the projection and a remainder of the push rod, and a washer having an approximately conical wall extending radially inwardly from an outer circumference of the washer towards a central mounting connection having a radial flange. A nut is threaded over the free end of the projection, and an opening in a hardened element is aligned axially with the projection to receive the projection. A circumferential groove defined in a side of the radial flange forms a boundary between the approximately conical wall and a remainder of the washer, and a portion of the diaphragm seal is pressed by the nut and the hardened element into the circumferential groove to produce a sealing bead.

A spring brake actuator (1) for a vehicle, in particular a parking or emergency brake actuator, for use in a commercial vehicle, includes a cylinder housing (2) having a cylinder housing base (5) and a spring seat (7) on the base, a spring brake piston (9) located in the cylinder housing (5) for applying a braking force, and a compression spring (11) arranged between the spring seat (7) and the spring brake piston (9). The cylinder housing (2) is divided into a spring chamber (12) and a pressure chamber (14), the compression spring (11) being arranged in the spring chamber (12) and the pressure chamber (14) being supplied with pressurized fluid. An elastically deformable diaphragm (16) is sealingly mounted to the cylinder housing (2), with an inner periphery (18) sealingly mounted to the spring brake piston (9) to fluid-tightly isolate the pressure chamber (14) from the spring chamber (12).

An actuating arrangement (1) for a parking brake of a motor vehicle, having a first actuating unit (5), for manual actuation of the parking brake, and a shaft (2) for transmitting braking forces (F1, F2) to at least one wheel brake cylinder (4) of a service brake of the motor vehicle. The first actuating unit (5) is operatively connected to the shaft (2) so that, when the first actuating unit (5) is actuated, a first braking force (F1) is transmitted via the shaft (2) to the at least one wheel brake cylinder (4). The actuating arrangement (1) has a second actuating unit (7) for the controllable actuation of the parking brake. The second actuating unit (7) is operatively connected to the shaft (2) so that, when the second actuating unit (7) is actuated, a second braking force (F2) is transmitted via the shaft (2) to the wheel brake cylinder (5).

An actuating arrangement (1) for a parking brake of a motor vehicle, having a first actuating unit (5), for manual actuation of the parking brake, and a shaft (2) for transmitting braking forces (F1, F2) to at least one wheel brake cylinder (4) of a service brake of the motor vehicle. The first actuating unit (5) is operatively connected to the shaft (2) so that, when the first actuating unit (5) is actuated, a first braking force (F1) is transmitted via the shaft (2) to the at least one wheel brake cylinder (4). The actuating arrangement (1) has a second actuating unit (7) for the controllable actuation of the parking brake. The second actuating unit (7) is operatively connected to the shaft (2) so that, when the second actuating unit (7) is actuated, a second braking force (F2) is transmitted via the shaft (2) to the wheel brake cylinder (5).