Abstract: An actuator for a lever that is connected, with a valve or a wastegate or a variable turbine geometry of an exhaust gas turbocharger. The actuator includes a connecting rod between a drive and the lever. The connecting rod is rotatably supported at a location some distance from the lever. The connecting rod is further guided between the support and the lever on a circular arc.

Abstract: An actuator is equipped with a cylinder body in the interior of which a piston is disposed for displacement therein. A piston rod connected to the piston projects outwardly to the exterior from an end of the cylinder body. A guide unit, having a guide body that is attached to the cylinder body, and a pair of guide rods, which are disposed displaceably with respect to the guide body, are disposed detachably on the cylinder body. Additionally, by mutually interconnecting the guide rods of the guide unit and the piston rod through a connecting plate, when the piston rod is displaced in an axial direction, the piston rod is guided by the pair of guide rods.

Abstract: A trim device includes a trim cylinder, a piston, a piston rod and a support member. The piston is slidable inside the trim cylinder, in the axial direction of the trim cylinder. The piston rod is connected with the piston and moves in the axial direction of the trim cylinder following the movement of the piston. The support member is slidable relative to the piston rod and arranged to support the piston rod so that the piston rod's axial center can become tilted with respect to the axial center of the cylinder.

Abstract: A pump that includes a piston moveable along a first axis and an eccentric cam positioned about a second axis, wherein the second axis is substantially perpendicular to the first axis. The pump also includes an actuator positioned adjacent to the cam and configured to move the cam along the second axis. In addition, the pump further includes a cam-adjacent bearing positioned between the piston and the cam, wherein the cam-adjacent bearing remains positioned substantially along the first axis upon movement of the cam along the second axis.

Abstract: A vibration damper with amplitude-selective damping force includes a cylinder containing a damping medium, a piston rod which is axially movable in the cylinder, and a piston assembly arranged for axial movement in the damping medium, the piston assembly being connected to the piston rod and dividing the cylinder into a working space around the piston rod and a working space opposite the piston rod, the piston assembly includes a piston body having connecting channels for opposite directions of flow between the working spaces, and valve disks which open the channels in respective opposite directions. A pilot assembly includes an axially movable shifting ring which controls a flow connection between the working spaces as a function of movement of the piston rod, and a pair of stop surfaces which limit axial movement of the shifting ring, wherein the stop surfaces are independent of the piston body and the valve disks.

Abstract: The brake actuator assembly of this invention significantly reduces accumulation of road debris, reduces the weight of the push rod and yoke assembly and friction between the mating parts. The brake actuator includes a housing defining a chamber having an opening through the end wall, a push rod and yoke assembly reciprocally mounted within the housing chamber and a shield located within the housing closely receiving the exterior surface of the push rod and yoke assembly which has a smooth substantially continuous external surface. In the preferred embodiment, the yoke is secured to the push rod within the housing chamber, surrounding the push rod having an elliptical exterior surface which sheds accumulation of road debris.

Abstract: The invention relates to a guide bushing between two components axially movable relative to each other, especially for guiding a piston rod subjected to longitudinal and transverse forces in the region of a piston rod seal of a hydropneumatic vibration damper. The guide bushing encompasses the piston rod, is held axially in a piston rod guide and is made of a material having good gliding characteristics. The guide bushing is arranged in the piston rod guide with a radial clearance having a gap with a changeable width when the piston rod is subjected to transverse forces created between the receptacle diameter of the piston rod guide and the outer diameter of the guide bushing.

Abstract: The device comprises a cylinder (3) and a piston (7) which is guided free of contact relative to the cylinder (3). A gap seal (12) is provided between the lateral surfaces (15, 14) of the cylinder (3) and of the piston (7). The gap seal (12) has a very thin and uniform annular cross section. The lateral surfaces (14, 15) of the cylinder liner (4) and of the piston (7) are essentially smooth and comprise a material with a linear thermal coefficient of expansion which is lower relative to steel. The precise maintenance of the sealing gap and the central guidance of the piston (7) in the cylinder liner (4) is ensured through two guides (8, 9) connected rigidly with the housing (5). These guides (8, 9) are elastic in the direction of the central axis (2) of the piston-cylinder unit and highly rigid transversely to the central axis (2).

Abstract: The invention relates to a novel design of a lifting column, especially for patient tables or for industrial applications, with at least one lifting cylinder designed as a hydraulic cylinder at least for one vertical stroke and with at least one guide assigned to at least one lifting cylinder for guidance in the direction of the stroke of the lifting cylinder.

Abstract: A fluid power operated advancing unit has housing and a plunger adapted to run axially therein. The plunger is designed in the form of a three sided prismatic body at least along its length section running in the housing, said body being guided in the housing at its three side surface, whereas three transitions between respective adjacent side are not guided. The result is accordingly an extremely accurate guiding action for the plunger while simultaneously preventing rotation thereof.

Abstract: A double acting hydraulic jack comprising a housing from which at least two pistons extend, each of the pistons being telescopic with respect to one another and with respect to the housing, and a counterbalance valve between adjacent pistons. The counterbalance valve allows hydraulic fluid to flow from an outer piston to an inner piston during piston extension and prevents back flow of hydraulic fluid, thus eliminating piston retraction during extension under load.

Abstract: A compressed gas and a liquid are contained in a cylinder. A liquid chamber containing the liquid and a gas chamber containing the gas are divided by a metallic bellows. The liquid chamber is situated on the side of an open end of the cylinder. A rod is inserted in the cylinder. A sealing assembly is provided at the open end of the cylinder. The sealing assembly has a bearing member at only one portion of the cylinder with respect to the axial direction thereof. A space extends throughout the circumference between the outer peripheral surface of the inner end of the rod and the inner peripheral surface of the cylinder. A seal device for sealing the liquid in the liquid chamber includes a seal ring intimately in contact with the outer peripheral surface of the rod and an elastomer ring provided on the outer peripheral surface side of the seal ring and capable of elastic deformation in the radial direction of the rod. The rod can swing within the range of an angle .theta.

Abstract: A pressure washer for delivering a liquid under high pressure has an inlet conduit connected to a liquid supply and an outlet conduit connected to a spray nozzle which can be operated to control the delivery of liquid through the nozzle. A bypass conduit enables recirculation of the liquid from the outlet conduit to the inlet conduit. A bypass system, disposed between the outlet conduit and the bypass conduit, includes a shuttle valve which moves between first and second positions at which it respectively blocks or opens the liquid path from the outlet conduit to the bypass conduit.

Abstract: A cylinder having a radially movable or pivoting rod slidably received in a floating gland disposed in a cavity or recess in an end cap of the cylinder. Preferably, seals are provided between the rod, gland and recess. Hence, the rod and gland can move radially while a fluid tight seal is maintained between the atmosphere and the interior of the cylinder to retain pressurized fluid therein. Preferably, to facilitate radial movement of the rod and hence the gland in the recess, the forces on opposed faces of the gland are equalized by an appropriate arrangement of seals to define equal surface areas on the opposed faces both of which communicate with the interior of the cylinder.

Abstract: A rod seal for a linear hydraulic or pneumatic actuator cylinder includes a seal ring that has a bore that closely matches the diameter of the rods, proximal and distal cylindrical portions and a central annular flange. A seat in the actuator cylinder distal end assembly has proximal and distal cylindrical portions and a central void to receive the rod seal ring proximal and distal portions and central flange respectively. A radial clearance is provided so that the rod seal ring can travel radially, at least for a limited distance, while the rod passes axially through it. Static elastomeric ring seals are provided in the proximal, distal and central portions, and define pressure balancing regions. The rod seal assembly can be constructed at low cost, yet achieve a high degree of sealing with low axial friction characteristics.

Abstract: Located in a stationary frame is a cylinder-piston unit, the piston of which is adapted to displace the bearing housing of a roll in a paper-making machine at right angles to the longitudinal axis thereof. The bearing housing is guided in the frame with the aid of linear guide-elements. The radial play between the piston and the cylinder-bore is greater than the transverse play between the said linear guide-elements. Furthermore, the axial length of the piston is less than the depth of the cylinder-bore. Whenever the cylinder-piston unit is relieved of its load, and the cylinder thus returns to its position of rest, it is centered in the cylinder-bore by means of a centering device.

Abstract: A double-rod hydraulic cylinder for an exerciser including a casing, a piston assembly and a universal joint. The piston assembly includes a piston head and two piston rods. Two bearings are respectively fixed to an inner wall of each closed end of the casing. A disk-type spring washer, a washer, an oil seal and a disk-like fixing gasket are arranged respectively in series from each bearing to said piston head. Each of the bearings, the disk-like fixing gaskets, the disk-type spring washers, the washers and the oil seals have a central hole in alignment for the piston rods to pass through. The washers, the oil seals and the gaskets are axially slidable a short distance within the casing. The two disk-like fixing gaskets and the piston head together define a first chamber and a second chamber. Each disk-type spring washer is compressed when the piston assembly axially moves in either direction. The hydraulic cylinder further includes an oil pipe.

Abstract: A power-assisted steering apparatus of the type which includes a control valve arranged to control hydraulic fluid under pressure supplied to a hydraulic power cylinder from a hydraulic pump therethrough in response to the driver's steering effort applied thereto, the power cylinder having a piston mounted therein for reciprocating movement and a piston rod supporting thereon the piston for movement therewith and extending outwardly from the cylinder in opposite directions. In the steering apparatus, a pair of axially spaced cylindrical reaction pistons are slidably mounted on the piston rod at the both sides of the power cylinder piston in such a manner as to be engageable at their inner ends with a pair of axially spaced internal end walls of the cylinder and at their outer ends with a pair of axially spaced retainer members on the piston rod when the power cylinder piston is retained in a neutral position.

Abstract: A turbocharging pressure controlling apparatus employing a diaphragm-type single acting air actuator includes a rod 33 to which is connected a control valve 13 for regulating the opening of a flow dividing hole 15 provided in an exhaust pipe 16 and which enlarges the degree of opening by a retracting motion, thereby reducing exhaust gas pressure for rotating a turbocharger that produces a turbocharging pressure and thus reducing the generation of turbocharging pressure. Through this arrangement the effect of operating directions of the rod upon the mounting position for the apparatus can be minimized. Therefore, the apparatus is not limited by the mounting position, as there is no effect thereon by the motion of the rod.

Abstract: An air-operated spring brake of the type wherein a spring-operated brake actuator is in tandem with an air-operated service brake actuator has a spring diaphragm which separates a spring housing into a fluid pressure chamber and a spring chamber. A spring in the spring chamber bears against a pressure plate to bias the diaphragm longitudinally in the spring housing in a brake-applying direction upon a decrease in pressure in the fluid pressure chamber. The diaphragm is movable generally longitudinally in the other direction to compress the spring in the presence of pressure in the fluid chamber to allow operation of the service brake actuator independently of the spring-operated actuator. A push plate, mounted to a push member, moves reciprocally with the diaphragm in the fluid pressure chamber in abutting relationship to the spring diaphragm.

Abstract: Improved lubricant control assemblies are disclosed for reciprocating piston rods of an engine which prevent crankcase lubricant intruding into the cylinders and fluid from the cylinders from escaping into the crankcase. Each assembly comprises a tubular sleeve fitting closely onto a piston rod and yieldably mounted within the bore between cylinder and crankcase through which the piston rod extends. The sleeve is urged into forceful contact around the piston rod by a plurality of disk members which forcefully urge the sleeve in contact around the piston and for controlling lubrication.

Abstract: A springless floating coupling for a plunger type pump connecting the drive plunger to a driven piston.

Abstract: A fail-safe system for use on a hydraulic piloted pressure reducing and regulating valve for holding the valve at the last selected operating pressure in the event of loss of control signals. A pressure regulating valve having a body and a control piston therein is provided with a pilot piston in the body which is adapted to be connected to and responsive to a hydraulic signal pilot pressure. A segmented locking ring surrounds the assembly and coacting concentric V-shaped locking grooves are provided between the locking ring and the assembly for locking the assembly. The segmented ring is biased towards an unlocked position. An annular cam ring engages the exterior of the locking ring. Coacting wedge surfaces between the cam ring and the locking ring are provided for locking and releasing the locking ring. The cam ring is biased for urging the coacting wedge surfaces into engagement.

Abstract: In a radial piston engine, in order to reduce the friction forces appearing at the pistons, a guide part is provided which engages a hollow piston through a guide section and which includes a bearing section at its outer end, by means of which the guide part is pivotably mounted in the cylinder cover.

Abstract: A pull-type booster for a vehicle includes a main body having an internal space; a movable body including a head portion and a cylindrical portion formed integrally with the head portion, the head portion being arranged in the internal space and partitioning the internal space into a lower pressure chamber at one side and a control chamber at another side, and the cylindrical portion projecting from the main body at the other side; a through hole formed in the movable body; a pull input rod extending across the lower pressure chamber and projecting through a seal assembly from the main body at the one side; the seal assembly including a seal member fixed to the main body at its outer circumferential portion and fitted to the pull input rod at its inner circumferential portion; a more flexible portion formed between the outer circumferential portion and the inner circumferential portion in the seal member; a plunger arranged slidably in the through hole and combined with a head portion of the pull input rod; a

Abstract: A rack-and-pinion steering gear structure for a vehicle including a rack housed within a cylinder driven by means of a pinion shaft, comprising: a bolt having a threaded portion screwed in a threaded hole formed in one end face of the rack and a shoulder linked integrally with the threaded portion and smaller in diameter than the rack but greater in diameter than the threaded portion; and a piston housed within a groove formed by the shoulder of the bolt, the seating surface of the bolt head, and the end face of the rack, with clearances with respect to the groove in the axial and radial directions.

Abstract: A seal assembly is arranged to contain leakage of hydraulic fluid passing between a wall opening and a penetrant rod portion passing through the opening. The seal assembly includes a sliding-seal member mounted on a portion of the rod for sliding movement toward and away from an abutment surface and a non-sliding flexible-seal member arranged between the body and the sliding-seal member. The body, flexible-seal member, sliding-seal member and rod define a sealed chamber into which such fluid will leak. The chamber communicates with a fluid reservoir through a oneway check valve. The sliding-seal and flexible-seal members are arranged in parallel with one another. In one embodiment, a spring urges the sliding-seal member to move toward an abutment surface provided on the rod. In another embodiment, movement of the sliding-seal member relative to the body is limited by facing abutment steps.

Abstract: Improved lubricant control assemblies for reciprocating piston rods of an engine which prevent crankcase lubricant intruding into the cylinders and fluid from the cylinders from escaping into the crankcase. Each assembly comprises a tubular scraper fitting closely onto a piston rod and yieldably mounted within the bore between cylinder and crankcase through which the piston rod extends. The yieldable mounting is by means of a compliant housing. The compliant housing allows the scraper to be displaced radially and thereby follow limited radial displacement of the piston rod while maintaining substantially full effectiveness of the scraper's action on the reciprocating piston rod. The scraper is urged into forceful contact around the piston rod by means of a crown spring which is supported on a tubular part which attaches to the compliant housing.

Abstract: Attitude control mechanism for a flexible bag component of a composite pneumatic chamber including a fixed section over which an inturned portion of a flexible bag pneumatic chamber section rolls includes a cantilever bag attitude control stem having its root anchored in a mounting closing the end of the flexible bag remote from the rigid pneumatic chamber section and extends through a central guide aperture of at least one frame mounted within the rigid pneumatic chamber section for substantially linear reciprocation guidance so as to prevent appreciable buckling of the flexible bag as it is contracted axially by movement of the mounting carrying the stem toward the rigid pneumatic chamber section.

Abstract: A pneumatic actuator is provided for a gate valve in a turbocharger system to control the bypass of exhaust gasses to regulate the speed of the turbocharger. The actuator includes a reciprocating rod connected at one end to a diaphragm and adapted to be connected at the other end to a pivoted lever for actuating the valve. A bearing is provided for the reciprocating rod with the bearing being moveably supported by a leaf spring arrangement mounted on the actuator for absorbing vibrations and transverse movement of the reciprocating rod.

Abstract: A hydraulic brake actuator for a wedge type brake includes a tubular structure extending from the brake and housing an extended end of a stem of the wedge of the brake therein. A primary cylinder is mounted on the tubular structure and includes a primary piston mounted for sealed movement therein. The piston has a rod extending from one side thereof into the tubular structure to be operably connected to the extended end of the stem. A spring acts on a second side of the piston and is capable of moving the piston toward a first position within the cylinder for actuation of the brake. Hydraulic fluid can be selectively introduced to the primary cylinder at the first side of the piston to cause movement thereof in opposition to the spring to a second position to prevent actuation of the brake by the spring. An annular space between an interior surface of the tubular structure and an exterior surface of the rod is sealed to prevent the hydraulic fluid from escaping from the cylinder.

Abstract: A control actuator for a turbocharger comprises an actuator rod coupled within an actuator housing to a pressure responsive diaphragm biased by a spring, and projecting out of the housing for connection to a turbocharger wastegate valve. A seal assembly on the rod accommodates sealed axial rod displacement, and includes a spherical seat maintained by a second spring in relatively low pressure pivotally sealing relation with the housing.

Abstract: A sealing bush unit for sealing a reciprocating machine part has an annular bush with an inner diameter exceeding an outer diameter of the reciprocating pump to form a radial gap therebetween, a radially outer surface arranged so that a working pressure acts upon the same and the bush radially displaces towards the reciprocating part, one flat end face facing toward a suction zone and providing an abutment for the sealing bush, and another end face facing toward a pressure zone, wherein a pressing ring is arranged adjacent to the other end face of the bush with axial play relative to a machine housing.

Abstract: The invention disclosed comprises an air cushion system that utilizes a two-diameter piston and a floating bushing to create an effective air cushion seal which prevents the piston from hitting the barrel bridge.

Abstract: A piston assembly is mounted at an inner axial end of the toothed portion of a rack within a tubular extension of a hydrosteering gear housing. The piston assembly includes a piston ring floatingly supported with axial clearance on the base portion of a mounting ring axially fixed to the rack at said inner axial end.

Abstract: A hydraulic rack steering system is provided with a unitary seal assembly around a piston rod which is a composite of compressible toroidal gaskets having an intermediate pre-stressing ring constructed and arranged to radially stress a plastic sealing ring against a piston rod. Thus, there is a sliding sealed relationship established between the piston rod and a composite sealing assembly secured within the servocylinder. The composite sealing ring assembly is carried in an assembly housing with the components locked in place therein by a closure ring press fitted into the housing. The cover ring is spaced from the composite sealing members in order to permit clearance for the piston rod to follow bending of a rack with which the piston rod is integral and wherein the rack is subjected to bending effected by steering stress.

Abstract: Anti-binding structure for jacks is provided which eliminates load-induced binding between an extended jack lift post and the guide structure therefor, so as to facilitate smooth jack operation. The jack of the invention preferably includes a rectangular or sqaure cross section lift post and a plurality of elongated, transversely U-shaped bearing channels respectively disposed between the planar post faces and the upper guide plate of the jack; the channels are each mounted for limited rocking movement about respective axes transverse to the longitudinal axis of the jack post so that any load-induced canting or deflection of the post can be safely accommodated without binding or galling thereof.

Abstract: A control actuator for a turbocharger comprises a diaphragm-displaced actuator rod projecting outwardly from an actuator housing through a seal permitting axial and angular rod movement for variably positioning a turbocharger wastegate valve.

Abstract: A fluid operated cylinder is provided including a tube having rod end and blind end caps which are attached to the tube by radial plugs. The plugs permit relative movement between the rod end cap and the tube when the cylinder is operated to accommodate axial misalignment between the piston rod and the tube.

Abstract: A hydraulic jack suitable for powering a large load such as an elevator or a drawbridge. In a first embodiment the hydraulic jack telescopes at a uniform rate over its entire distance of extension and includes a plunger member telescopingly enclosed within a sleeve member which, in turn, is telescopingly enclosed within a cylinder member, with the cylinder member encircled by an oil jacket within which the cylinder member is capable of limited angular movement. Means are provided for angularly aligning the various members within one another. Means are also provided to restrict the flow of hydraulic fluid as the hydraulic jack reaches a limit of its travel. Hydraulic jacks in accordance with the present invention can be coupled together in systems to lift large loads.

Abstract: A rolling stand with hydraulic adjustment of the mill rolls comprises a hydraulic cylinder whose piston is acted upon by the adjustment spindle and whose cylinder body, in turn, bears upon the block in which the back-up or pressure roll is journaled. The sliding seal of the piston rides in a cylinder lining which is disposed in the cylinder and is sealed relative to the latter with stationary O-rings so that pressure equalization on both sides of the liner is possible, thereby preventing expansion of the line upon subjection of the cylinder to high pressures.

Abstract: An oil hydraulic power steering device of the rack and pinion type which includes a rack rod supported for lateral oscillation about a fulcrum adjacent one end thereof and a power actuator comprised of a piston secured to the rack rod, an outer cylinder, and an inner cylinder in which the piston is slidably fitted and which is floatingly supported in the outer cylinder. The device further includes a spring for normally biasing the rack rod against the pinion and a mechanism for engaging the normally free end of the rack rod while laterally displacing the rod end to increase the backlash in the rack and pinion gearing as the rack rod approaches the end of its stroke. There is no excessive pressure of contact occurring between the meshing gear teeth and the backlash is self-adjustable as the teeth wear down.

Abstract: Improved brake actuators of the type having both service chamber and spring emergency-parking chambers utilizing piston in each said chamber (no diaphragms); improved double piston brake actuator wherein the service chamber is inboard of the spring emergency chamber; improved double piston brake actuator having an inboard spring emergency-parking and an outboard service chamber.

Abstract: This invention relates to a non-rotatable fluid powered nozzle and valve combination which includes a cylinder having a piston reciprocally received therein for movement between two reciprocated positions and which defines two separated fluid chambers therewith. A piston rod secured to the piston is slidably received through one end of the cylinder, the cylinder being provided with two ports communicating with said two chambers, respectively. The piston and piston rod conjointly having a longitudinally extending passage therethrough. A hexagonal pin is disposed in one of said chambers and is slidably received in sealing relation by a hexagonal portion of the aforesaid passage. The pin is secured in the other end of the cylinder for limited radial but against longitudinal movement with respect to the cylinder.

Abstract: The device comprises on the front end portion of the plunger or piston a retaining ring mounted in the barrel with the interpositioning of a joint in such a way that the bore of the ring is slightly off-center relative to the piston axis when the joint is not deformed.

Abstract: An improved fluid cylinder including a housing defining a cylinder bore and having aligned piston rod openings at opposite ends thereof, which openings are nominally coaxial with the bore. A piston rod is within the bore and extends through both of the openings and a piston is located within the bore and includes a central opening receiving the rod and having a shape complementary to that of the rod while being slightly larger than the rod so that the piston may move radially on the rod. Securing elements are provided for fixing the axial position of the piston on the rod and include an annular shoulder abutted by the piston. A seal is interposed between the piston and the shoulder to preclude leakage of the working fluid therebetween. The relative radial movement of the piston on the rod compensates for lack of precise concentricity of the bore with respect to the rod receiving openings.

Abstract: A rack and pinion steering gear mechanism for use with the dirigible wheels of a road vehicle comprising a steering gear pinion adapted to be connected to a vehicle steering linkage, a power rack engageable with the pinion and adapted for reciprocating linear motion, said rack including a power piston mounted within a power cylinder which define a pair of opposed pressure chambers, a steering shaft connected yieldably to the pinion by a torsion shaft, fluid pressure control valve means including relatively displaceable parts forming in part fluid connections between a pressure source and each of said pressure chambers, one valve part being connected to the pinion and the other part being connected to the steering shaft whereby distribution of working pressure to the pressure chambers is dependent upon the direction of torque applied to the steering shaft, the magnitude of the pressure buildup in the pressure chambers being proportional to the degree of displacement of the steering shaft relative to the pinion

Abstract: A double acting power boost cylinder comprising a movable servo piston for vehicle steering purposes is provided with means comprising a fixed piston protruding into a bore of the servo piston so as to reduce the effective end surface pressure receiving areas of the servo piston. Thus, the total forces acting to drive the servo piston are reduced to avoid overload or damage to a steering mechanism driven by the servo power piston. The invention has its utility in vehicles where a common hydraulic source is used for various purposes such as steering, brakes, vehicle level and the like where pressures required may vary and where the pressure required for steering is not as great as required for other purposes. Usually accumulators are used and the invention is of particular utility since it permits the use of small pumping devices.

Abstract: An oscillating fluid-driven actuator for a shaft, such as a ship rudder shaft, a butterfly valve spindle or the like. The actuator comprises (i) a stationary actuator housing defining an annular chamber coaxial with the shaft and having a suitable cross section, and (ii) an annular piston arranged coaxially with the shaft in the chamber and connected fixedly with the shaft by means of an arm mounted intermediate the ends of the annular piston by means of a central piston hub. The piston hub is made with a coaxial bearing surface or surfaces of convex spherical shape and the actuator housing has a central lower hollow hub defining an inner concave spherical bearing surface to support the piston hub by engagement with the spherical surface thereof. A corresponding concave spherical bearing surface is arranged in the upper portion of the housing to cooperate with the corresponding spherical surface of the upper portion of the hub.

Abstract: Improved brake actuators of the type having both service chamber and spring emergency-parking chambers utilizing piston in each said chamber (no diaphragms); improved double piston brake actuator wherein the service chamber is inboard of the spring emergency chamber; improved double piston brake actuator having an inboard spring emergency-parking and an outboard service chamber.