Abstract: A brake slack adjusting apparatus is disclosed which includes a threaded member at least partially extending coaxially within a tubular member. Threadedly engaging the threaded member is a first rotatable member for varying the relative position of the rotatable member with respect to the threaded rod member. A second rotatable member disposed adjacent the threaded rod member and the tubular housing member selectively couples the tubular housing member to the threaded rod member during a brake application stroke to transmit brake forces to the threaded rod member and to vary the relative axial position between the tubular housing member and the threaded rod member. A locking device is provided between the first rotatable member and the second rotatable member to limit the relative movement between the first rotatable member and the threaded rod member when a predetermined force is transmitted through the second rotatable member.

Abstract: A braking unit for vehicles is disclosed which includes a housing in which slides a piston that can be displaced by means of a pressurized fluid to control, by means of an actuator, a thrust rod which controls a brake shoe. The actuator includes at least one pair of coaxial rollers supported so that they can revolve around a pin, supported by a pair of legs, which is connected to the piston and displaced in rolling contact with inclined surfaces of the thrust rod.

Abstract: Parking brake control apparatus on a vehicle equipped with electrofluidic responsive brakes is disclosed. The apparatus comprises a parking brake on the vehicle operable by a cylinder. A source of pressurized fluid provides fluid pressure to the cylinder. The cylinder responds to fluid pressure to release the parking brake and responds to apply the parking brake when fluid pressure is vented. A directional valve connected intermediate the source of fluid pressure and the cylinder controls fluid communication to the cylinder in one position and vents fluid pressure from the cylinder in a second position. Movement to the second position is controlled on one side of the valve by an electrovalve which responds to electrical signals and on the other side by a cylinder which responds to fluid pressure and can only occur when both an electrical signal is below a predetermined minimum and the fluid pressure is reduced.

Abstract: A braking apparatus and method are taught that allows the vehicle having the apparatus to resume operation when the magnitude of an electrical signal to an electro-fluidic portion of the apparatus is less than a minimum predetermined value. The system uses electro-fluidic braking equipment to supply pressurized fluid in response to an electrical signal and fluid pressure controlled braking equipment to supply pressurized fluid in response to pressure differentials. An automatic selector value (ASV) normally receives pressurized fluid from the electro-fluidic equipment. When a minimum predetermined value electrical signal is not present, however, the ASV receives pressurized fluid from the fluid pressure controlled braking equipment. The system incorporates a release device to isolate the electro-fluidic braking equipment from the ASV when the electrical signal is less than the minimum predetermined value. Thereafter, the equipment may resume operation.

Abstract: A brake actuator device having a pneumatic service brake piston and a spring parking or emergency brake piston operation of either one of which effects displacement of a brake actuator rod which includes a screw-threaded spindle that operates in a non-rotatable nut member in order to adjust the length of the actuator rod. The nut member is provided with an external projection to which the vehicle brakes are mounted. A cogwheel is rotatably fixed to the actuator rod and is normally locked against rotation by a locking pin that engages the cogwheel teeth. The actuator rod is formed in two portions that are connected together through a clutch arrangement, the actuator rod portion having the threaded spindle being free to rotate during brake release to increase the actuator rod length and thereby take up the brake slack.

Abstract: A vehicle brake unit having a fluid pressure operated piston arranged perpendicular to a brake push rod on which is provided a pair of diagonally opposed roller members. An actuator member is connected to the piston and is interposed between the piston and push rod to translate the force of the piston to the push rod. A thrust surface having a cam profile is engageable with the roller members of the push rod, while a reaction surface is engageable with the brake unit housing. The actuator reaction surface is convex and the complementary thrust surface of the housing is concave, thereby providing a pivot point about which the actuator is angularly rotated when the piston is operated to establish a brake stroke of the brake push rod.

Abstract: An LC series resonant regulator is connected across the output of the inverter circuit of a static converter apparatus to vary the output voltage level as the inverter operating frequency varies from a preselected frequency at which the regulator circuit is tuned. The load is coupled across the capacitor element of the regulator and a level detector coupled across the load input. This detector registers variations of the input to the load from a predetermined desired level of load voltage and supplies a feedback signal, indicative of any detected variations, to the control circuit for the inverter circuit element. This control circuit is responsive to a feedback signal to vary the operating frequency of the static inverter so that the regulator varies the output voltage applied to the load to restore the desired voltage level.