Abstract: A compressed air system includes an air drying subsystem which can be configured either in an intermittent mode, in which a separate purge volume intermittently purges the desiccant used by the air drying systems when the compressor goes off load, or in a continuous flow mode, in which the purge volume is replaced by a second desiccant cartridge and the two desiccant cartridges are alternatively purged and used to dry the compressed air.

Abstract: A fluid pressure system and stoplight control circuit for a towed vehicle which is either an intermediate unit or the last unit of a vehicle train includes an inlet supply line for receiving fluid pressure from a preceding unit and an outlet supply line which is connected to a corresponding coupling of a succeeding unit when the vehicle is an intermediate unit and which is connected to a coupling hanger when the unit is the last unit of a vehicle train. A pressure responsive stop light switch is connected into the coupling hanger. Accordingly, when the outlet supply line is connected to the coupling hanger, the contacts of the stop light switch are closed, thus permitting power to the stop lights when a brake application is effected. However, when the outlet supply line is connected to a succeeding vehicle, the coupling hanger is vented, so that the contacts of the pressure responsive switch are open, thus interrupting power to the stop lights and conserving power on the vehicle.

Abstract: A signal generator for generating an electrical signal which varies in accordance with movement of an actuating member includes a plunger slidable mounted within a housing which carries a pair of permanent magnets for generating a magnetic field to be applied to a hall effect generator. As the plunger is moved relative to the hall effect generator, the magnets are also moved relative to the hall effect generator, thereby varying the magnetic field applied thereto. Accordingly, a variable output signal is generated as a function of the position of the input member.

Abstract: A fluid pressure responsive valve includes a valve member mounted on a guide pin slidably carried by a piston. A valve guide is engaged by one side of the valve element, and the piston engages the opposite side. The piston controls the valve member. The valve guide acts as a stop for a check valve element that controls communication through the inlet port, and also guides and supports the spring controlling the check valve element.

Abstract: An engine traction control system generates a control cycle of a varying duty cycle which controls the pressure level in a pneumatic actuator in the engine power control linkage to thereby reduce engine power when the driven wheels begin slipping during the vehicle acceleration. The duty cycle is set as a function of wheel speed error between the average wheel speeds of the driven and non-driven wheels, and also as a function of the change in the error between calculation cycles.

Abstract: A fluid pressure braking system for a tractor-trailer combination vehicle includes a proportioning relay valve which controls communication to the rear wheel brakes of the tractor. When the tractor pulls a trailer, the proportioning control within the relay valve is disabled, but when the vehicle is operated in the "bobtail" mode without pulling a trailer a proportioned brake application is effected in which the braking pressure communicated to the rear brake actuator is a predetermined percentage of that in the front wheel braking circuit. The proportioning mechanism is also disabled when the front axle braking circuit malfunctions, so that upon loss of pressure of the front axle system, the driver effects a non-proportioned rear brake application.

Abstract: In a method of manufacturing a brake booster, a step of defining a fixed distance between a peripheral surface on a rear shell of the brake booster and an eye of a linkage member attached to a brake pedal when the movable wall is in a rest position. The wall in the brake booster is adapted to be rotated with respect to a variable surface on the rear shell which acts as a stop for the wall in the rest position. The location of the wall with respect to the variable surface establishes a desired fixed linear dimension between a peripheral surface on the rear shell and an eye on the linkage member which is attached to connecting pin the brake pedal. When the control valve is in the rest position this fixed linear dimension also defines a corresponding fixed location for the pad of the brake pedal with respect to a floor panel in a vehicle.

Abstract: The invention relates to a solenoid valve, in particular for a hydraulic braking circuit of a motor vehicle with a wheel antilockup device, the solenoid valve being disposed between at least a pressurized fluid source (52) and at least a pressure receiver (56) and comprising, in a body (10), a piston mechanism (24) which can be displaced between a rest position, in which it permits communication between the pressurized fluid source (52) and the pressure receiver (56), and a work position, in which it permits communication between the pressure receiver (56) and a low-pressure fluid reservoir (66). According to the invention, the piston mechanism (24) is permanently stressed toward the rest position by a constant force.

Abstract: A liquid filter element includes a circumferentially extending array of pleated filtering material. The end sections of each of the pleats are folded over and crushed together, and are embedded in a plastic plug to form a rigid link extending substantially transversely with respect to the array to thereby strengthen the array against inward radial collapse in response to liquid pressure acting on the array. A process for making the element is disclosed which includes the step of forming a circular array of pleats, applying pressure to the end sections of the pleats to crush the pleats and rigidify them, and then bending the rest of the array about the rigidified portion to form the thimble-shaped filter element.

Abstract: The apply and release hydraulic parking valve (20, 120) comprises a housing (40, 140) having therein a bore (42) with first (52, 152) and second (54, 154) reservoir grooves communicating with one or more reservoir ports (46, 146A, 146B), a supply groove (63) communicating with a supply port (47, 147), and apply (44, 144) and release ports (48, 148) communicating with said bore (42, 142). A spool valve (60, 160) is located slidably within the bore (42), the spool valve (60, 160) activated by a lever (31, 131) received within an opening (67, 167) of the spool valve (60, 160). One end of the spool valve (60, 160) has a pair of washers (74, 76) disposed thereabout with a spring member (80, 180) located about the spool valve (60, 160) and between the washers (74, 76), and a stop sleeve (82, 182) located about the spool valve (160, 60). The spool valve (60, 160) includes a chamfered groove (61) engaging a check valve (50, 150) within the supply port (47, 147).

Abstract: A test for an electronically controlled braking system, such as an adaptive braking system, is made to assure that the solenoids of each of the modulators are properly wired. According to the test, each modulator is tested in sequence. The exhaust solenoid of a modulator is actuated for 10 milliseconds, and the hold solenoid is then actuated for 30 milliseconds. If the modulator has been miswired, the exhaust solenoid will have been actuated for 30 milliseconds, thus generating a much louder "popping" sound than that generated by the other modulators will be immediately noticed and corrected.

Abstract: A method of manufacturing a tandem brake booster by selectively choosing a front shell having a first cylindrical body with first effective diameter, a transition shell having a second cylindrical body with a second effective diameter and a rear shell having a third cylindrical body with a third effective diameter. The cylindrical body of the transition shell is an integral component of an end wall which separates the interior the resulting tandem brake booster. The end wall has a peripheral ledge with a flange extending therefrom and a groove located on the flange connected to the second cylindrical body. An annular surface on the first cylindrical body is crimped into the groove on the flange while a corresponding annular surface on the second cylindrical body is crimped onto the third cylindrical to join the transition shell with the rear shell to form an integral unit.

Abstract: The production of complex cavities inside castings or semi solid forms is effected by forming a core pattern (10) of a low melting point metal in order to provide a rigid metal core pattern (10). The pattern (10) is then nickel coated using either electroplating or electroless nickel plating. The metal core pattern (10) is melted out of the nickel plating to provide a nickel liner core (16). The nickel liner core (16) is placed within a mold or die cavity, and molten metal introduced into the cavity in order to provide a casting or form (30). The casting or form (30) is removed from the cavity and includes therein a plurality of passageways (20) each of which is defined and surrounded by a corrosion resistent nickel liner surface (22).

Abstract: An electromagnetic valve for controlling a passage for a flow of fluid or for a difference in the pressures between an inlet (48;56) and an outlet (56;48), comprises a body (10;16;46) on which is arranged a solenoid coil (22), a bore (26) in which is slideably mounted valve member (30) progressively displaceable in response to actuation of the solenoid coil (22) between a first position and a second position. The valve member (30) and the body (46) comprises cooperating valve surfaces (54;62) defining the passage. One valve surface (62) has in axial section a variable profile so that the area of the passage, in a radial section is a predetermined function of the intensity of the current applied to the solenoid coil (22).

Abstract: The drum brake has two shoes (12, 14), each presenting a web (16) and a rim (18) whose face facing the drum receives a friction lining (20). The drum brake is arranged on a support plate (10), and the web (16) of each shoe (12, 14) possesses a notch cooperating with a strut (40) determining the separation of the shoes (12, 14). The strut (40) bears in the neighborhood of one of its ends (50) a pivot (52) on which is articulated an actuating lever (46) extending substantially perpendicular to the support plate (10) through an opening (54) made in the latter in hinged and capable of cooperating with one of the shoes. The actuation of the drum brake is obtained by a simultaneous action and reaction on the actuating lever (46) and on the strut (40).

Abstract: A traction servomotor for supplying a control valve with an operational input independently of an operator pedal assembly in response to a signal supplied to a controller indicating a different rotational spin of the wheels of a vehicle. The traction servomotor has a housing with an input rod with a first section retained in axial openings in the housing and a second section is pivotally connected to the operator pedal assembly. The interior of the housing is divided by a diaphragm which is attached to the first portion of the input rod. The controller is connected to the housing such that in a first mode of operation wherein the activation of the control valve is dependent on an input from the operator pedal assembly a first fluid pressure is presented to both sides of the diaphragm and in a second mode of operation, a second fluid pressure is presented to one side of the diaphragm to create an actuation pressure differential.

Abstract: A compressor assembly includes a housing, and a rotatable impeller within the housing which includes a hub and blades extending from the hub. A ring circumscribes the leading edge of the blades, and cooperates with a groove in the housing to define a clearance therebetween which is larger than the clearance between the connecting edge of the blades and a corresponding conforming portion of the housing. This permits free flow of gas around the ring to enhance the operating range of the compressor wheel. The ring also stiffens the blades, permitting the thickness of the hub to be reduced, thereby further enhancing the operating range of the compressor wheel.