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: 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 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.

Abstract: A control for an electropneumatic braking system applies a step function to a electronically operated proportional modulator to improve transient response. The current is controlled by a treadle operated signal generator operated by the vehicle operator and by actual feedback braking pressure as generated by a pressure sensor which senses braking pressure. The system includes a master controller which receives and processes information from the operator operated treadle operated signal generator and transmits desired pressure signals to wheel controllers which independently control each wheel of the vehicle.

Abstract: Air dryer for a compressed air system includes a desiccant canister and a tubular oil filter received within a cavity within the canister circumscribed by a desiccant bed. A tubular oil filter is mounted on a removable module so that the module and the oil filter may be removed from the air dryer without disturbing the desiccant canister. Accordingly, the oil filter is replaced at more frequent intervals than is the desiccant. During purging, purge air is bypassed around the oil filter directly to the exhaust port through a check valve permitting communication through a bypass passage only during purging.

Abstract: An air dryer for compressed air braking systems includes a desiccant canister which is provided with a double helix insert which cooperates with the walls of the canister to define a pair of intertwined, serpentine, pneumatically isolated flow paths. The flow paths extend through the canister between the end walls and are filled with a desiccant material. A single center line valve mechanism is provided to switch between the flow paths so that one of the flow paths is purged at the same time that the other flow path is pressurized.

Abstract: A compressed air system includes an air dryer which includes a desiccant for drying compressed air passed through the desiccant before the compressed air is received in a storage reservoir. A humidity sensor is installed in the system downstream of the desiccant for measuring the relatively humidity of the air after it passes through the air dryer. A control module is programmed such that if the humidity level increases above 80%, a timer is started. If a time period of several hours elapses without the humidity level decreasing below 50%, a depleted desiccant and/or a system malfunction is indicated, and an appropriate warning device is actuated.

Abstract: A liquid filter includes an annular filter cartridge and a combination anti-drain back and relief valve assembly. The combination valve includes a valve seat from which axially extending arms extend and a spring retainer and spring which holds a gasket against the valve seat. The gasket includes an anti-drainback portion which projects from the valve seat and a relief valve portion which is supported on the valve seat. Upon assembly the combination valve and filter element in the housing, the filter assembly is supported by the spring retainer and is forced into sealing engagement with the gasket, holding the latter against the valve seat in a gasket engaging area between the relief valve portion and the anti-drainback portion. This assembly process also removes the coil spring load from the barbs on the valve seat arms.

Abstract: A fluid pressure braking system for a tractor trailer vehicle includes a supply line connecting the tractor and trailer braking systems. A low pressure responsive switch responds to the pressure level in the supply line for actuating a warning device when the pressure level in the supply line drops below a predetermined pressure level to thereby warn the driver before a brake actuation is effected that a low pressure level exists in the trailer braking system. A normally open stoplight switch is connected in series with the low-pressure responsive switch so that the signal generated by the low-pressure responsive switch is prevented from actuating the warning device when the tractor is operated in the "bobtail" mode without a trailer.

Abstract: An engine exhaust gas system includes a conduit for transferring exhaust gas, and a butterfly valve within the conduit for controlling communication of exhaust gas through the conduit. The butterfly valve is mounted on a shaft for pivoting relative to the conduit. The shaft is supported on a bushing in a transverse bore. Leakage through the clearance between the bushing and the shaft acts upon the transverse face of a washer which is freely slidable on the shaft, urging the latter into engagement with a retaining ring carried on the housing to effect sealing of the clearance. As the pressure of exhaust gases increases, the washer is urged more forcefully against the retaining ring, thereby improving the effectiveness of the seal.

Abstract: Two different types of converter boxes (38, 84) provide the required interface for transmitting service brake control signals from the tractor unit (12) of a tractor-trailer combination vehicle to the trailer unit (16) thereof in which the tractor unit (17) and trailer unit (16) are provided with dissimilar braking systems. One type of converter box (38) provides the interface between a tractor (12) equipped with an electropneumatic braking system in which service brake applications are controlled by electrical signals and a conventional trailer (16) in which service brakes are controlled by pneumatic signals. The other type of converter box (84) provides the required interface between a tractor (12) which has service brakes controlled by conventional pneumatic signals and a trailer unit (16) which is provided with and electropneumatic braking system in which service brake applications are controlled by electrical signals.

Abstract: A limited service application of the service brakes of the trailer portion of a tractor trailer combination vehicle is applied and held while the vehicle operator gets out of the cab to make a pre-trip inspection. The service actuation is initiated by releasing the trailer parking brakes while the tractor parking brakes remain applied and then making a momentary service brake actuation by use of the vehicle dual control valve. A control valve assembly responds to the service actuation to hold a service actuation of the trailer brakes until either the tractor parking brakes are released or the trailer parking brakes are applied.

Abstract: A clutch drive mechanism for the cooling fan of an automotive engine includes a driving member rotated by the vehicle engine and a driven member carrying fan blades. The driving member includes an axially movable portion which is rotated through drive pins slidably received in bores in the axially movable portion. Resilient grommets are carried in the walls of the bores and engage the pin to prevent noise and rattling as the clutch members are engaged and disengaged. Grooves are provided on the pins which receive the grommets when the axially movable portion is in the fully disengaged position, which allows the axially movable portion to move to a truly centered position with respect to the spindle, thereby eliminating stress on the components when the mechanism is in the released condition.

Abstract: The dual braking unit includes a cylinder with a diaphragm 4, 11-17) for controlling the service braking and a cylinder with a drive spring (3, 6-10) for controlling the parking and emergency braking. The cylinder with the spring includes a piston (6, 10) with an operating tube or tubular push rod (10) which extends sealingly through a hole (5) in a wall (2) separating the operating chambers (8; 12) of the cylinders. There is a pair of holes (35, 36; 35, 34) in the tube (10) for enabling communication between the chamber (7) with the spring (9) and the operating chamber (12) of the cylinder with the diaphragm when only the parking and emergency brake is applied. A cut-off valve device (40-43) is associated with the holes (35, 36; 34. 35) for preventing air from flowing from the operating chamber (12) of the cylinder with the diaphragm to the chamber (7) with the spring (9) when the service brakes are applied while the parking and emergency brake is applied.

Abstract: The regulator supply valve (100, 101, 200, 300, 400, 500, 600, 740) of the present invention provides regulated fluid pressure for adaptive braking and traction control systems (10, 710) operation. The regulator supply valve (100, 101, 200, 300, 400, 500, 600) and system (10) may be supplied as an add-on feature for a standard braking system. During adaptive braking system operation, pressure from a chamber (28, 30; 718, 716) of a master cylinder (12, 712) causes the regulator supply valve (100, 101, 200, 300, 400, 740) to communicate a pressure source (35, 720) with modulators 41, 42; 51, 52; 61, 62, 71; 746, 748, 752; 746', 748', 752') for respective wheel brakes (40, 50, 60, 70; 750, 760).

Abstract: The master cylinder (30) includes primary and secondary pistons (42, 52) each of which has a center compensation valve member (44, 60). An abutment member or pin (38, 40) extends across a bore (36) of the master cylinder (30) adjacent ends of each of the pistons (42, 52) and the pins (38, 40) are each engaged by shafts (45, 64) of the spring biased valve members (44, 60) of the primary and secondary pistons (42, 52). An output rod (43) of a vacuum booster (41) to which the master cylinder (30) is attached disposes the primary piston (52) slightly spacedapart from the respective pin (40) in an at-rest position. The primary piston (52) includes a self-adjusting compensation center valve seat (70) located within the primary piston (52), the valve seat (70) sealingly and slidingly movable relative to the primary piston (52). The valve seat (70) extends through a rear opening (59) of the piston (52) to engage the respective pin (40).

Abstract: An air dryer control system is disclosed in which the compressed air output of a compressor is dried by one of two air dryers connected in parallel. The purging and drying cycles of the air dryers are alternated by timing and relay device. Upon start-up, the output of the compressor is dried by both air dryers until the pressure level in the supply reservoir attains a predetermined level. When the governor cutout pressure is achieved in the reservoir, both air dryers are purged.

Abstract: A turbocharger includes a turbine housing with a variable geometry mechanism which controls the flow area of the throat through which motive exhaust gasses are communicated to the turbine wheel. The turbine housing is provided with an insert which defines one wall of the throat and which is cast in place as part of the turbine housing. The insert may be made of a relative expensive, high nickel content material to assure that a non-corrosive surface is provided adjacent to the vanes which are pivotally actuated to vary the area of the throat. The remainder of the housing is made of a standard ductile iron which is substantially less expensive than the more expensive corrosive resistant high nickel content material from which the insert is manufactured.

Abstract: A method and apparatus for providing charge air to the intake manifold of an internal combustion engine at high pressure levels at low engine speeds without compressor surge provides an auxiliary turbocharger which receives a portion of the compressed air produced by a main turbocharger at low exhaust gas flow conditions. The remainder of the compressed air generated by the turbocharger under such low exhaust gas flow conditions is communicated through the compressor section of the auxiliary turbocharger, where the pressure of the compressed air is further increased to a level sufficient to provide charge air at an adequate pressure level to the intake manifold of an internal combustion engine to permit efficient operation of the engine with minimal emissions at low engine speeds.

Abstract: The rotating components of an exhaust gas driven turbocharger are supported by a pair of axially separated ball bearings having an outer race and an inner race. A spacer between the bearings engages the outer race of both bearings and exerts a preload bias on the outer races of the bearings urging the outer races away from one another. Accordingly the bearings are preloaded so that centrifugal forces generated during high speed operation will not force the ball bearing away from the inner races.