Abstract: A full function skid control valve assembly for use in an air brake system which provides for brake control utilizing a compact single assembly. The system provides for the maintenance of certain minimum operating pressures so that, when the air pressure within the vehicle brake system falls below predetermined levels, the valve assembly automatically partially or entirely exhausts the air pressure sometimes causing the spring parking brakes to engage. Once the air pressure within the brake system returns to predetermined levels, the valve assembly will allow a reservoir to be charged and the spring brakes to be deactuated. During operation, the assembly provides control of the service brakes while preventing undesired skid conditions.

Abstract: A contaminant-ejecting, pneumatically-controlled brake booster valve is disclosed. The valve comprises an exhaust piston slidably mounted within the stem of a main piston of the valve, wherein the exhaust piston is actuated by supply air pressure to periodically open and close an exhaust passageway leading from the main piston chamber to an exhaust area. Pressurized supply air normally forces the exhaust piston in the exhaust passage blocking position thereby preventing the escape of control air through the exhaust passageway. When supply pressure is released (e.g. when the parking brake is applied), pressurized control air forces the exhaust piston upward, allowing some of the control air to escape through the exhaust passageway to the exhaust area. The escaping control air expels any moisture or other contaminants that may have accumulated in the main piston chamber. Additionally, a check valve is positioned in an orifice of the main piston.

Abstract: A hydraulic system for accommodating fluid pressure variations is provided. The system includes a housing for an actuating piston with the housing having a first end with a hydraulic fluid port and a second end. The actuating piston includes a body portion, having a face, and a rod portion. A first resilient member is confined between the actuating piston and the second end of the housing. A second resilient member is confined between the body portion and the face of the actuating piston. The face of the actuating piston is preferably a pressure accommodating piston which moves relative to the body portion of the actuating piston. Preferably, the second resilient member has a tension force greater than the tension force of the first resilient member. As the actuating piston moves against the bias of the first resilient member toward the second end of the housing in response to hydraulic fluid entering the housing through the fluid port, the movement of the actuating piston is limited by a stop.

Abstract: A long-stroke fail-safe spring brake assembly for heavy duty vehicles comprises aligned first and second cups secured adjacent one another to form a housing for a compressed power spring which biases a spring piston, a hollow tubular push rod having one end open and sealingly secured, preferably by press fitting, to the spring piston and the other end closed and extending sealingly through the second cup for reciprocal control of a brake actuator by the power spring, an annular-shaped flexible diaphragm having an outer periphery radially-sealingly secured adjacent between the cups and an inner periphery sealingly secured adjacent the outer periphery of the spring piston, the intermediate portion of the diaphragm being disposed radially-outwardly of the spring piston. The spring piston is disposed to compress the compressed spring still further toward the first cup under the influence of a compressed fluid medium, the push rod, and the spring piston being sealingly secured to each other.

Abstract: A full function skid control valve assembly for use in an air brake system which provides for brake control utilizing a compact single assembly. The system provides for the maintenance of certain minimum operating pressures so that, when the air pressure within the vehicle brake system falls below predetermined levels, the valve assembly automatically partially or entirely exhausts the air pressure sometimes causing the spring parking brakes to engage. Once the air pressure within the brake system returns to predetermined levels, the valve assembly will allow a reservoir to be charged and the spring brakes to be deactuated. During operation, the assembly provides control of the service brakes while preventing undesired skid conditions.

Abstract: A simplified integrated full-function valve for heavy duty brake systems comprising a valve body having individual ports for fluid communication with spring brake chambers, service brake chambers, pressurized-air reservoir and exhaust and for receiving pressurized control and supply air from respective sources thereof; internal passageways within the valve body providing selected fluid communication with the various ports; a plurality of valve modules within the valve body comprising a spring brake valve module, a relay valve module and a biased one-way pressure protection valve module, and disposed to selectively determine the fluid communications within the internal passageways and ports responsive to the respective positions of the valve modules; the port and related internal passageways for the spring brake chambers being fluid-communicatively-isolated from the reservoir, the service brake chambers and the control air, whereby the number of the internal passageways within the valve body is minimized; the

Abstract: A braking system is improved by addition of a spring brake pressure protection valve, to prohibit pressurization of the spring brakes prior to the build up of sufficient pressure to insure complete release of the spring brakes. This prevents the significant problems associated with known systems that permit operation of a tractor trailer with partially released spring brakes, which will cause unnecessary wear and reduced fuel economy. The spring brake pressure protection valve is located between the reservoir and the spring brakes, most preferably between the spring brake quick release valve and the spring brakes, or alternately, between the reservoir and the spring brake quick release valve.

Abstract: A crankshaft assembly provides a combination of a clutched hollow crankshaft for driving a reciprocating device with a driveshaft for driving another device. The drive shaft extends through the crankshaft and is powered by the same flywheel as is used to drive the crankshaft. The assembly permits selective transmission of power to those devices only when they need power. In the preferred embodiment, the drive shaft provides continuous power while the crankshaft provides power as needed by engaging and disengaging the crankshaft clutch.

Abstract: A full-function brake valve for a tandem trailer is contained within a single housing and provides a boost to the control air signal arriving at the full-function valve so that the control air signal can be delivered to a second trailer full-function valve without degradation of the control air signal. The signal boost function is provided by an aperture in the piston of the relay valve that connects the control air inlet to the supply air, to cause the supply air pressure to boost the control air signal.

Abstract: A full function valve incorporating a proportioning valve module that initially directs supply air pressure during initial system charging to the spring brake chambers to prepare the spring brakes for prompt release when there is sufficient system supply air pressure to operate the service brakes. The proportioning valve module then opens to increase supply air pressure to the reservoir, while charging of the spring brake chambers continues, until the service brakes become operable and the spring brakes disengage.

Abstract: A full function brake valve for a semi-trailer is contained within a single housing and provides ports for receiving supply air and control air, and for delivering and receiving air from reservoirs, service brakes and spring brakes, and delivering air to an exhaust. The internal valves include a reservoir check valve and a relay valve to respectively pressurize a reservoir and to deliver supply air to service brakes. A secondary reservoir is supplied via a secondary reservoir check valve and a secondary reservoir outlet in the full function valve, or in a secondary relay valve, and is controlled by a secondary relay valve module to provide a redundant braking system for additional safety.

Abstract: A simplified and less-costly quick-release valve with controlled hysteresis for a vehicle spring-set air-release parking brake system lengthens the operating life of the valve, reduces energy consumption, extends compressor life and alleviates noise problems. The valve comprises a valve body and a plurality of internal passageways each of which is selectively connectable to at least another of the passageways. The selective connection is controlled by an integrally-formed flexural spring-brake-control release diaphragm within the valve body and disposed to either isolate or selectively connect the passageways depending on the relative pressure conditions within the passageways and respective areas of the diaphragm exposed to the pressures. The components are designed so that the normal variations or cycling of the supply or intake pressurized air does not cause cycling of the pressure in the spring-brake chambers.

Abstract: A full function brake valve for a semi-trailer is contained within a single housing and provides ports for receiving supply air and control air, and for delivering and receiving air from reservoirs, service brakes and spring brakes, and delivering air to an exhaust. The internal valves include a pressure protection valve which communicates with a first check valve and a quick release valve to pressurize spring brake chambers, and a reservoir check valve and a relay valve to respectively pressurize a reservoir and to deliver supply air to service brakes. An orifice preferably provided in a second check valve permits partial air flow to the spring brakes to release the spring brakes for towing the vehicle.

Abstract: A full function skid control valve assembly for use in an air brake system which provides for brake control utilizing a compact single assembly. The system provides for the maintenance of certain minimum operating pressures so that, when the air pressure within the vehicle brake system falls below predetermined levels, the valve assembly automatically partially or entirely exhausts the air pressure sometimes causing the spring parking brakes to engage. Once the air pressure within the brake system returns to predetermined levels, the valve assembly will allow a reservoir to be charged and the spring brakes to be deactuated. During operation, the assembly provides control of the service brakes while preventing undesired skid conditions.

Abstract: A proportioning module for automatically changing the ratio of delivery pressure to control pressure according to whether a mode control pressure is present or absent. When the mode control pressure is present, the proportioning module is deactivated, causing the delivery pressure to be substantially equivalent to control pressure. When the mode control pressure is absent, the proportioning module functions to provide control pressure to delivery pressure ratios which are dependant upon the control pressure and the resultant delivery pressure.

Abstract: An indicator unit for a vehicle air brake system is provided which includes a brake rod mounted for movement between a non-braking first position and a predetermined safe maximum braking second position. A pivotally mounted slack adjuster is connected to the brake rod and is responsive to the movement of the rod. An indicator unit is provided which has a first section removably mounted on the connection between the rod and adjuster, a second section retained in a predetermined alignment with the rod, and a third section angularly disposed relative to the second section. The unit third section is provided with angularly disposed, exposed, first and second reference marks. When the rod is in the first position, the first reference mark is aligned with a predetermined first segment of the adjuster. When the rod is in the second position, the second reference mark is aligned with the predetermined segment of the adjuster.

Abstract: An air dryer is provided which permits the purge air to bypass the coalescing filter during the unloading cycle in order to minimize the back pressure in the desiccant filter, decrease the purge time of the dryer, and increase the efficiency of the air dryer. In one embodiment, the air dryer may have a passage disposed between the coalescing filter and the desiccant filter so as to permit purge air to bypass the coalescing filter during the unloading cycle. A turbosaver valve may also be disposed so that it controls not only the flow of air through the coalescing filter but also the discharge of the purge air and the contaminants. Disposing the turbosaver valve intermediate the upstream and downstream sides of the coalescing filter insures that the turbosaver valve passes the compressed air through the coalescing filter in the loading mode while permitting the purge air to by-pass the coalescing filter in the unloading mode.

Abstract: A valve assembly for use with spring-set air-release vehicle parking brakes comprises a particular arrangement of conventional components providing desired spring brake operational characteristics heretofore requiring costly, complex specially-designed units. The valve assembly typically employs a plurality of interconnected check valves in combination with pressure protection and quick release valves to provide the desired characteristics. These include a system whereby at startup pressurized air from the tractor fills the trailer reservoir tanks and the spring brake chambers simultaneously. The valve assembly also assures that if during tractor-trailer operation the supply air from the tractor is severed or otherwise lost, service brake air in the trailer reservoir tanks is retained at a sufficient pressure to provide adequate service brake operation.

Abstract: A clutch brake assembly is provided for operatively connecting to a rotatable shaft. The clutch brake comprises at least two arcuate members, each having first and second ends, and inwardly extending tabs for engaging standard grooves in the shaft. The clutch brake further includes a first fastener for pivotally coupling the first ends and a second fastener for connecting the second ends of the arcuate members to form an annular assembly about the shaft. The arcuate members may be preassembled such that they are pivotally coupled at their first ends prior to installation. During installation of the clutch brake around the shaft, the first arcuate member is installed around the shaft and the second arcuate member is then pivoted toward the shaft in a plane substantially perpendicular to the axis of the shaft. The second fastener is then installed.

Abstract: An integrated gladhand and quick-release valve for tractor-trailer highway vehicles is mounted on the tractor, as opposed to the trailer, so the operator of a particular tractor will uniformly have quick-release capability for any trailer drawn by the truck. The integrated gladhand and quick-release valve provides an inlet port for fluid communication from the tractor brake system and an outlet port for fluid communication to the trailer brake system. The intermediate passageway that provides fluid communication between the inlet and outlet ports contains a valve element. The valve element may be apertured to allow limited, continuous fluid communication between the tractor and trailer brake lines. During the quick-release mode, the tractor side is substantially isolated and the trailer side is vented through an exhaust port. The present invention provides a uniform and safe braking system for tractor-trailer highway vehicles where the tractor operator does not own or maintain the trailers.