Abstract: A pneumatic booster includes a movable wall mounted in a hollow body to divide the interior of the body into a low pressure chamber and a high pressure chamber, the movable wall having an internal bore extending therethrough. An input member is movably received in the bore and carries a plunger. A valve member is selectively engageable with a first valve seat formed on the plunger and a second valve seat formed on the surface of the bore for controlling a pressure differential between the low and high pressure chambers. At least one pin slidably extends through the movable wall and is engageable with a rear wall of the body for allowing the movable wall to move rearwardly relative to the pin. An operating member has a tubular portion slidably received in the bore and is connected to the pin for movement therewith. An output member and a load-transmitting member for transmitting a load to the output member in response to a forward movement of the input member are received in the tubular portion.

Abstract: The servomotor incorporates a component (50, 51) for retaining and positioning the plunger (12) forming the movable seat (11) for the valve mechanism (9) of the servomotor, the retaining component incorporating a cylindrical component (50) pivoting in the valve body (8) about an axis perpendicular to the direction of movement of the plunger (12), provided with a longitudinal groove (57) bounded by a first cam surface (58) cooperating with a shoulder (47) of the plunger (12) and a follower lever (51) outside the valve body (8) and incorporating a profiled edge (60) cooperating, on the return of the servomotor towards its rest position, with a ring (43) mounted in the neck (21) of the casing (1).

Abstract: A brake system includes a brake booster coupled to a front wheel brake cylinder. The brake booster substantially defines a pair of rear wheel brake cylinders separate from the front wheel brake cylinder so that a pair of diaphragms are separated during braking to generate a power assist for the front and rear brake cylinders. A control valve cooperates with the brake booster to alter the power assist for the rear brake cylinders in response to a signal from an electronic control unit.

Abstract: A power brake booster, in which the valve piston is slidably supported in the control hub and cooperates with the poppet valve, that is formed of any rubber-elastic material. The poppet valve is designed as a cone valve. Thus when the valve passage is opened, atmospheric air enters the working chamber from the air chamber through the opening, that is arranged in the control hub transversely to the booster's longitudinal axis, to flow in almost undisturbed and without turbulence. To ensure a reliable sealing seat, the peripheral surface of the truncated-cone-shaped end of the valve piston is equipped with a curcumferential groove, the one lateral wall of the groove forming together with the peripheral surface a sealing edge which reliably abuts on the plane plate surface of the poppet valve when the valve is closed.

Abstract: Differential pressure brake boosters are known having a reinforcement tube extending axially through the low-pressure casing with its ends fastened to both end surfaces of the casing. A mechanically actuated control valve for connecting the working chamber to the low-pressure chamber or to atmosphere is axially movable in the reinforcement tube. A sleeve surrounding a master cylinder piston push rod has radial ribs extending through longitudinal slots of the reinforcement tube to connect the push rod to the movable wall. These ribs are subjected to a high bending stress. According to the present invention the radial ribs are constructed as flat tongues disposed in a common plane, the tongues being engaged on a side thereof adjacent the low-pressure chamber by an outwardly angled collar of an extension of the housing of the control valve.

Abstract: An hydraulic booster has a boost piston which works in a bore and is subjected to boost pressure in a boost chamber to actuate a master cylinder assembly, and a control valve assembly controls pressurization of the boost chamber in response to an input load applied to a pedal-operated input member. The input member works in a bore in the boost piston and in operation, a reaction load from the master cylinder is fed back through the booster to the input member through a reducer mechanism to provide a reaction at the pedal which is not affected by the boost pressure, and the reducer mechanism is received within a recess in the boost piston, which is defined between two relatively movable parts of the boost piston.

Abstract: A brake system for a vehicle comprises a booster unit including a power piston disposed slidably in a housing for defining a first chamber and a second chamber in the housing, a regulator disposed slidably in the power piston, a flow restrictor formed between the first chamber and a fluid pressure source for restricting flow of fluid in response to movement of the regulator, a pilot pressure chamber disposed upstream of the flow restrictor, a movable member moved by the internal pressure of the pilot pressure chamber thereby permitting communication between the second chamber and the fluid pressure source, and a reaction spring disposed between the power piston and the regulator. A master cylinder is connected to the power piston of the booster unit to supply braking hydraulic fluid at controlled pressure to front and rear brakes, and a brake pedal actuates the regulator of the booster unit to cause movement of the regulator relative to the power piston.

Abstract: A fluid pressure servomotor for automotive vehicle wheel brake system including a housing having a movable wall therein for reciprocable movement, the movable wall dividing the housing into two compartments, one on each side of the movable wall. The two compartments cooperate to produce a pressure differential on opposite sides of the movable wall that causes the wall to be moved by the higher pressure in the direction of the lower pressure. The servomotors further have a control valve operated by the operator of the vehicle that regulates the degree of vacuum or less than atmospheric pressure established at one side of the movable wall. The movable wall is usually connected with the master cylinder of the hydraulic brake system of the motor vehicle so that when a pressure differential is effective on the movable wall and hence a power movement of the wall is produced, hydraulic fluid is displaced from the master cylinder into the hydraulic fluid brake system to apply the hydraulic brakes of the vehicle.

Abstract: A servo amplification system is created particularly for heavy construction equipment, but has a general utility that is much broader. The system utilizes a hydraulic analog system with a separate subsystem for each dimension of motion. The operator moves the operative element, such as the backhoe bucket, of the analog replica which ordinarily would be situated in the cab of the backhoe or other piece of equipment. A small hydraulic cylinder operative in response to movement at each articulated connection of the backhoe operates a pilot valve which controls a pilot piston mechanically linked to the drive valve of the drive cylinder of the corresponding articulation in the actual backhoe. A feedback system comprising a mechanical link from the actual drive piston to a feedback cylinder and piston delivers hydraulic fluid back to the inlets of the pilot valve in such a way as to cancel the pilot orders from the initial control cylinder.

Abstract: A vacuum power servo booster having an improved retainer for an annular seat of a control valve body. A spring seat for a compression spring which presses the annular seat against the valve housing is formed at the front end portion of a retainer. A recess is formed on the front side of the spring seat to receive the skirt of the control valve body. The spring seat is formed by bending a smaller diameter portion of the retainer inwardly prior to assembly. In this manner, the longitudinal axis of the retainer is made to substantially coincide with that of the control valve body.

Abstract: For use in a brake booster of the type having a master cylinder disposed rearwardly of a booster mechanism having a power piston and in which a braking reaction force produced on an output shaft is transmitted therefrom to an input shaft through a reaction disc and a reaction transmitting member, an apparatus is provided for adjusting the magnitude of a clearance defined between the reaction disc and the reaction transmitting member. In this apparatus, the input shaft comprises a first section associated with the reaction transmitting member and a second section on which a valve seat is formed. The valve seat forms a valve mechanism disposed within a valve body for controlling the opening or closing of a passage for hydraulic fluid. The first and the second section of the input shaft are formed by separate members, both of which project toward the front shell and are connected together in a manner to permit their relative position to be adjusted.

Abstract: A master-cylinder and brake booster assembly in which the movable piston of the booster is mechanically coupled to the piston or pistons of the master-cylinder by means of a pulling rod protruding from the axial wall of the atmospheric actuation enclosure of the depression chamber of said booster.

Abstract: In a mechanical gear selector for a synchronized gear change, there is disposed an automatic force amplifier--primarily a hydrostatically operating automatic amplifier--that amplifies or amplifies the force introduced depending on the magnitude thereof, no separate energy such as a fluid pump being needed therefor, and the amplification also taking place only when needed, primarily for the synchronization of gears. Between a force input shaft and a casing disposed concentrically thereto, which casing also transmits the amplified force, there is situated in connection with an annular and a pressure space the force amplifier proper and a spring element for the defined amplification threshold. On the design depends from what input force amplification starts. From a defined amplified pressure, the amplifying action is terminated by a pressure-reducing valve so that the transmission of force is continued practically with this pressure that has been reached or a pressure therebelow.

Abstract: A vacuum responsive switch for detecting a failure in creation of a control vacuum within the control diaphragm chamber. A solenoid valve is provided which functions to equalize pressure within one of a power diaphragm chamber and a leak chamber with the other when vacuum represented by a signal from the vacuum responsive switch is lower than a predetermined value.

Abstract: A servo booster mechanism (18) having a piston (48) responsive to movement of a plunger (84) by an input signal for controlling the rate of fluid flow past a seat (82) into a passage (80) for distribution to the surrounding environment. A first restrictor (75) creates a first pressure drop in a supply fluid pressure P.sub.s to present an operational chamber (46) with fluid at a pressure P.sub.x. A second restrictor (openings 74-76) creates a second pressure drop in fluid pressure P.sub.x supplied from the operational chamber (46) to present control chamber (88) with fluid at a pressure P.sub.h. The difference in pressures combine to act on the piston (48) and plunger (84) to provide a constant force at stem (26), which provides a feedback to the input member (12), and provide a linkage (22) with a force to hold a position sensor (24) in a stationary position.

Abstract: A vacuum booster device which is mainly used to operate a master cylinder for hydraulic brakes or the like of automobiles. The device is so constructed that the inner peripheral bead of the diaphragm disposed within the booster shell and the clamping band adapted to clamp the bead tightly are fitted in the annular fitting groove formed in the rear surface of the booster piston, a part of the inner peripheral bead is formed as a thin-walled elastic valve portion which is in close-contact with the inner surface of the annular fitting groove in a separable manner and which engages with the notched recess formed in the rear side wall of the fitting groove, and the relief is provided between the valve portion and the clamping band to allow deformation of the elastic valve portion. Thus, when the pressure within the first working chamber is increased, air can be discharged from the first working chamber to the second working chamber through a gap made in the relief region due to deformation of the valve portion.

Abstract: A control valve 44 for use in a fluid pressure operated motor 10 to control the communication of fluid between first and second chambers 34 and 36. The control valve 44 includes a plunger 58, a disc 46 and a retainer 70. The retainer 70 has a cylindrical body 82 with an inwardly projecting lip of which section 84 engages and holds the peripheral surface 48 against shoulder 78 on the hub 26 and an end section 94 which acts as a stop to limit the movement of plunger 58 in bore 38 when the valve 44 is in the released position. Tabs 100, 100'. . . 100.sup.N on sleeve or cylinder 82 are located in groove 102 to lock the retainer 70 in place. In response to an input, push rod 56 moves plunger 58 to allow disc 46 to move and initially interrupt communication of a first fluid between the first and second chamber 34 and 36 and thereafter permit a second fluid to flow into the second chamber 36.

Abstract: A pneumatic servo booster including a housing, a power piston unit partitioning the interior of the housing into front and rear chambers and having therein a first passage with one end opening to the front chamber and the other end opening to the interior of the power piston unit and a second passage with one end opening to the rear chamber and the other end opening to the interior of the power piston unit, and a valve mechanism provided in the interior of the power piston unit and being associated with an input rod to control the communication between first and second passages and between the second passage and another passage which is communicated with a source of a first reference pressure. A plurality of diversion channels are provided in at least one of the first and second passages to decrease the speed of the air flow in the passage and to rectify the air flow thereby suppressing noise.

Abstract: A reaction force mechanism for a brake power booster includes an elastic member (53) which forms a hydraulic pressure reaction force chamber (50) and is spaced from an end surface (17d) of an input shaft (17) by a predetermined distance (.delta.) so that braking hydraulic pressure is not immediately detected by a driver. In addition, a passage (57) normally provides communication between the hydraulic pressure reaction force chamber and a primary side pressure chamber (45) of the master cylinder, and, alternatively, provides communication between the hydraulic pressure reaction force chamber and a secondary side pressure chamber (46) of the master cylinder when no hydraulic pressure is established in the primary side pressure chamber of the master cylinder.

Abstract: A vacuum booster assembly in which a diaphragm member is coupled over a piston body at its inner peripheral bead and secured to the inner wall of a housing of the booster assembly at its outer peripheral bead, and an annular support plate is attached to one face of the diaphragm member and has an inner cylindrical portion coupled with the inner peripheral bead of the diaphragm member to fasten the same to the piston body. The annular support plate is made of thin sheet metal and formed at its radially inward circumference with an annularly pressed portion, and an annular reinforcement plate of thick sheet metal is integrally secured to the annularly pressed portion of the support plate and has an inner cylindrical portion coupled with the inner cylindrical portion of the support plate.

Abstract: A vacuum type brake booster device comprising a first and a second working chambers defined in a booster shell by a booster piston, tie rods extending through the booster piston for connection of the front and rear walls of the booster shell so as to support loads on the booster shell, flexible bellows surrounding each of the tie rods and having opposite ends fixed respectively to the tie rod and the booster piston so that the inside of the bellows is communicated to the second working chamber, and an adjustable stop mechanism provided on an input rod for adjusting a retraction limit of the latter, whereby a control valve is held in a neutral position to keep the second working chamber out of communication with the first working chamber and the external atmosphere so that the bellows becomes expansive owing to a pressure difference between the working chambers for getting out of contact with the tie rod and, accordingly, for keeping the movement of the booster piston undisturbed.

Abstract: A power assist apparatus (18) having a first shell (32) connected to a second shell (34) by a twist lock arrangement (41). The shells (32) and (34) are made of a light weight and flexible material such that when subjected to temperatures above 120.degree. F. the pressure differential created by vacuum on the inside of the shells (32 & 34) and atmospheric pressure on the outside of the shells (32 & 34) a crushing force is produced that urges the end (33) of the shell (32) toward shell (34). A plurality of struts (98) located between the shells (32 & 34) resists this crushing force to maintain the minimum spacial relationship between shells (32 & 34).

Abstract: A tandem type brake power servo booster and toggle joint include a cylindrical member which has a first engaging portion for engaging a second engaging portion of a front power piston so that relative rotation between the cylindrical member and the front power piston can be prevented when a nut is tightened to secure the cylindrical member and the front power piston into position. In addition, a key member extends through a valve body and a hub of the cylindrical member to engage a valve plunger, and a surface of the key member which faces a push rod is spaced apart from the valve body to form a clearance between the valve body and the key member surface, thus providing the toggle joint with increased strength. In addition to the nut which serves as a stop, a second stop is formed on the hub so that the first and second stops integrally join the valve body and a center body of the cylindrical member with each other.

Abstract: A brake power servo booster including a stationary stop provided on the cylindrical projection of a rear shell, and a movable stop provided on an input shaft connected between a brake pedal and a valve mechanism, and operationally associated with the stationary stop to restrict the retracted position of the input shaft. An intermediate stop member is slidably provided in the cylindrical projection, and has its retraction restricted by the stationary stop. The input shaft extends slidably through the intermediate stop member. The movable stop is adapted for abutment on the intermediate stop member to restrict the retracted position of the input shaft.

Abstract: An integral valve body of elastic material for use in the multiple function valve of a vacuum-operated brake power booster has two roughly circular cylindrical parts which are arranged one behind the other. Two annular portions of the valve body which succeed the cylindrical parts are formed to be particularly rigid. A bellows portion which forms a roll fold and interconnects the annular portions has an S-shaped longitudinal sectional profile in the longitudinal direction of the valve body, the profile being comparatively thin-walled.

Abstract: The two chambers (8, 9) on either side of the movable wall structure forming a piston (7) are each sealingly delimited internally by a first and a second flexible impervious walls (23) which connect the central hub part (11) incorporating the control valve (12) to the central annular end zones (22 ; 24) of the corresponding end walls (2 ; 3) of the housing, the central zones delimited peripherally by said flexible walls being interconnected by at least a passage (39) traversing the central hub part, thus providing in the center of the housing a neutral cylindrical zone (32). In this neutral zone (32) there extend force-transmitting elements (38) which have at their ends fastening means (40), for example with assembly flanges (41, 42), and which slidingly pass through said passages (39) formed in the body of the central hub part (11), thus in no way interfering with the control and fluid actuation system of the servo-motor.

Abstract: A tandem-type brake booster including a closed shell assembly composed of front and rear chambers defined by a partition member therein and power pistons coaxially disposed in the front and rear chambers, respectively, the power pistons being operatively coupled with each other and passing through a substantially central portion of the partition member, each of the front and rear chambers being divided into a constant-pressure chamber subjected to a vacuum and a variable-pressure chamber communicable selectively with the constant-pressure chamber and atmosphere, the constant-pressure chambers in the front and rear chambers being held in communication with each other, the variable-pressure chambers in the front and rear chambers being held in communication with each other, the power pistons being axially movable in unison by pressure differences between the constant-pressure chambers and the variable-pressure chambers, respectively, one of the front and rear chambers having an outside diameter smaller than tha

Abstract: A vacuum booster which includes a push rod, a housing having a first and second compartment, a power piston located in the housing and operated by a pressure differential between the first and second compartments and which further includes a small and large diameter portion, a control valve operatively associated with the push rod and located within the power piston for controlling the pressure differential between the first and second compartments in response to movement of the push rod, an output member having a first end slidably disposed within the large diameter portion of the power piston wherein the control valve includes an air-valve element one end of which is slidably disposed in the small diameter portion of the power piston a resilient reaction disc located adjacent the first end of the output member and disposed within the large diameter portion of the power piston, a metallic sleeve provided between an outer peripheral portion of the first end of the output member and an outer peripheral portion

Abstract: In a vacuum suspended type servo device, there is arranged a power ratio adjusting means for adjusting the power multiplying characteristic of the servo device to a desired degree.

Abstract: The stop key (60) for the plunger (50) of the valve means (30) of the servomotor (10) is mounted without play in a radial recess of the hub (19) of the working piston (20), the key having a flat body portion and two angularly folded lateral edges, the recess having a constant axial dimension essentially identical to the overall thickness of the key.

Abstract: A retainer 226 for holding a control valve 656 of a servomotor 42 in a bore 90 of a hub 78. The hub 78 which is attached to a movable wall 56 has first 92 and second 96 passages that connect the bore to first 86 and second 88 chambers in the servomotor 42. The retainer 226 limits the movement of the control valve 656 in the bore 90 to establish a full release position whereby the pressure of the fluid in the first 86 and second 88 chambers equalize. In response to an input force, the control valve 656 moves to an actuation position where fluid under pressure is communicated to the second chamber 88 to create a pressure differential across the movable wall 56. The pressure differential acts on the movable wall 56 to develop an output force corresponding to the input force. On termination of the input force, the control valve 656 moves to the full release position where the fluid pressure equalization occurs.

Abstract: In vacuum brake boosters for motor vehicles, the vacuum casing is conventionally made of sheet steel. The vacuum casing is subjected to mechanical and pneumatic forces which have to be absorbed by the casing components. This makes it necessary to construct the casing components so they are strong enough to take these forces. The result of such construction is, however, high costs and high weight. To eliminate these disadvantages, the invention provides a brake booster wherein the vacuum casing includes a pipe therein extending in approximately coaxial of the longitudinal axis of the vacuum casing and connected to the transverse end walls of the vacuum casing, the pipe enclosing the master cylinder push rod, and the movable wall of the brake booster is sealed relative to the pipe and slidable thereon.

Abstract: A brake booster comprising a housing which is divided into a vacuum chamber and a working chamber by a movable wall. A tube is disposed in the housing coaxial of the longitudinal axis thereof having its ends fastened to the end walls of the housing. The tube is provided with longitudinal slots in the vacuum chamber which are open remote from the movable wall. Parts of the movable wall project through the slots and are fastened to a valve housing extending into the tube, the valve housing containing a control valve which controls the pressure in the working chamber. This arrangement allows a short overall length of the booster and enables easy assembly thereof with respect to known prior art brake boosters.

Abstract: A brake apparatus 10 having a master cylinder 16 with a flange 24 connected to a first shell 56 of a booster 18 and a stationary firewall 71 of a vehicle. A first wall 70 located between the flange 24 and first shell is connected to a piston 38 in the master cylinder 14. A second wall 144 located between the first shell 56, flange 24 and a second shell 121 is linked to the first wall 70 by a plurality of bolts 180 that pass through the flange 24. A valve 102 in response to an input controls the development of a pressure differential across the first and second walls 70 and 144. This pressure differential creates a force such that the first wall 70 pushes piston 38 while the second wall 144 pulls the first wall 70 to pressurize fluid in the master cylinder 16. Since the flange 24 fixes the master cylinder 16 to a stationary firewall 71, measurable axial deflection is eliminated and the entire input is used to operate valve 102 and effect a brake application.

Abstract: Brake power multiplying devices for automobile brake systems include a housing having a pressure responsive flexible diaphragm for dividing the inside chamber of the housing into a suction pressure chamber and a counter-pressure chamber. A piston made of a plastic material is attached to the diaphragm and houses an air valve and a control valve which are adapted to be actuated by a push rod operated by a driver of the automobile through a brake pedal or like operating member. A key member made of a metallic material is provided for holding the air valve on the piston. The key member includes a pair of outer holding arms having tip ends attached with rubber members so that it does not damage the plastic piston.

Abstract: A pneumatic booster includes a housing, a power piston and flexible diaphragm assembly partitioning the interior of the housing into two chambers, a poppet valve mechanism for selectively connecting or disconnecting communication between the two chambers and disconnecting or connecting communication between one of the chambers and a reference pressure, an input rod for actuating the poppet valve mechanism and an output rod connected to the power piston. The poppet valve mechanism includes a plunger connected to the inner end of the input rod, a valve member, a valve body having an axial bore therein for slidably receiving the plunger, and a restricting member mounted on the plunger for restricting the relative axial displacement of the plunger and the valve body. A resilient member is interposed between the restricting member and the valve body to avoid impacting abutment between the restricting member and the valve body.

Abstract: A negative pressure type booster arrangement comprises a pair of booster shells divided by a booster piston disposed therein for reciprocating movement into a constantly negative pressure chamber and a variable pressure chamber. The second chamber is always put in interchangeable communication with the first chamber via a control valve mechanism. An input rod is retractively connected to the booster piston, and is also connected to the valve control mechanism for permitting the booster piston to follow advancement of the input rod due to a difference in air pressure between both chambers. An input transmitting lever is mounted on the rear end of the input rod. A first arm is provided for supporting an operating lever extending successively from the booster shells and for pivotally supporting one end of the input transmitting lever, and a second arm is provided for supporting an operating wire.

Abstract: A fluid pressure device wherein a relatively low powered analog electrical signal accurately controls the position of the output member of a fluid pressure powered actuator which in turn can be used to exert mechanical forces or operate mechanical devices such as fluid pumps, motors or valves. Inlet and outlet passages communicate a control pressure chamber to high and low pressures respectively. A control element totally within the chamber so as to have balanced pressure forces thereon and made of a magnetically sensitive material is moved to a fixed position in the chamber proportional to the strength of an externally generated magnetic field. At least one of the passages moves with the output member so as to be opened or closed by the control element relative to the other passage. The output member follows the control element automatically varying the pressure in the chamber to compensate for any variations in the external forces thereon.

Abstract: A braking-force booster which contains a pressure source, a pedal operated control valve and at least one main brake cylinder; a piston which creates the brake pressure, is exposed to the pressure created in the main brake cylinder by means of the control valve, wherein the control valve, dependent on the pedal displacement, interrupts a connecting channel between the main brake cylinder and a pressureless connection and temporarily creates a second connecting channel between the pressure source and the main brake cylinder. The pedal operated control valve contains a plunger movable by the pedal which extend into the main brake cylinder, and the first connecting channel is integrated into the main brake cylinder piston. The first plunger has a valve closing member for shutting off this connecting channel during the corresponding approach.

Abstract: Servomotor with reduced idle stroke of actuation without decrease in valve lift on release of the brake.According to the invention, the rest position of the actuating rod 36 is determined by movable stop 60 capable of withdrawing on release of the brake in order not to impede lift of the valve poppet 32 relative to the seat 40, which allows, in the rest position, these two elements to be brought closer with a short distance d, thus reducing the idle stroke of actuation.Application to power-assisted braking.

Abstract: A fluid motor (10) having a housing (12) with first (14), second (16) and third (18) chambers therein. A first partition (22) separates the first chamber (14) from the second chamber (16). A second partition (24) separates the second chamber (16) from the third chamber (18). The third chamber (18) is connected to a source of fluid under pressure. A valve mechanism (91) controls the communication of the source of fluid between the second (16) and third (18) chambers. A poppet valve (42) allows the fluid to flow into the first chamber (14) from the second chamber (16). The first chamber (14) is connected to the third chamber (18) through a check valve (118). The valve mechanism (91) responds to an operator input signal by terminating fluid communication between the second (16) and third (18) chambers and initiating communicationof the second chamber (16) with the atmosphere to allow fluid to escape and create a pressure differential across the first (22) and second (24) partitions.

Abstract: A vacuum type brake booster device is provided which comprises a booster shell of substantially elliptical shape in transverse cross section, a booster piston of similar shape as the booster shell and accommodated therein for axial reciprocating movement, and a diaphragm secured about the outer periphery thereof to the booster shell and about the inner periphery to the booster piston to divide the interior of the booster shell into a first working chamber in communication with a vacuum source and a second working chamber adapted to be selectively placed in communication with the first working chamber or the atmosphere by a switching valve. The diaphragm is also shaped substantially elliptically in transverse cross section, and includes a pair of opposite straight peripheral wall sections and a pair of opposite arcuate peripheral wall sections interconnecting the straight wall sections; the arcuate wall sections have a wall thickness greater than that of the straight wall sections.

Abstract: A highly durable and light-weighted vacuum type brake booster device including a booster shell, a booster piston axially slidably accommodated in the booster shell to divide the interior thereof into a first chamber communicating with a vacuum source and a second chamber adapted to be placed into selective communication through a control valve with the first chamber and the atmosphere, and an input rod operatively connected with the control valve for operating the latter to generate a pressure differential between the first and second chambers. The front and rear walls of the booster shell are connected with each other by means of tie rod(s) which extend(s) through the booster piston with a deformable seal member disposed therebetween. The booster piston is urged in a retracting direction by a return spring disposed in the first chamber.

Abstract: This invention relates to an automatic temperature control system for automobiles and improved components thereof. The control system operates on the proportional stroke principle and comprises an in-car air sensing tube biased with ambient air; a sensor in an aspirator at the end of the tube; a moving pivot operated directly by the output of the sensor; and a feedback valve operated by the moving pivot for driving a vacuum-assist motor, the output stroke of which operates the various electrical and vacuum functions of the heater-air conditioning system.

Abstract: In order to reduce the forces transmitted by the reaction device of a vacuum brake booster, there is provided a first booster piston directly connected to the booster's output member and a second booster piston of smaller size acting solely on the reaction device. Both booster pistons are controlled by a control valve carried by the second booster piston. The second booster piston is arranged inside an internal cylindrical sleeve penetrating the first booster piston and interconnecting the transverse end walls of the booster housing.

Abstract: Air pressure servomotor including front shell and rear shell coupled to said front shell so as to construct a housing, a diaphragm disposed in the housing, a piston plate located adjacent the diaphragm, input rod and output rod. The front and rear shells hold a cylinder structure which extends axially from the wall of the front shell to the wall of the rear shell and supports the shells axially, and which has slits running from the forward end to the intermediate portion thereof. A valve having a valve mechanism is slidably disposed in the cylinder structure and having a valve mechanism. Said input rod is connected to the foot pedal and the output rod is connected to the master cylinder. And when the foot pedal is operated to actuate the input rod, the action of the input rod is amplified by the operation of the valve mechanism and the piston plate and transmitted to the output rod therethrough, and then the master cylinder is actuated.

Abstract: To provide a space inside the housing of a brake booster for installation of an end portion of a master brake cylinder, the hub member of the booster piston (movable wall) comprising an axial sleeve adapted to embrace an end portion of the master cylinder in the actuated position of the booster and a valve housing extending out of the booster casing opposite to the master cylinder and guided therein, the valve housing including internal longitudinal channels extending from its outer end to a chamber which surrounds the valve housing and leads to the working chamber of the brake booster.

Abstract: To reduce the load or force exerted on the housing of a vacuum brake booster, the master cylinder housing extends axially through the booster housing thereby connecting the two end walls of the booster housing together. The master cylinder housing is directly attached to the splashboard of the vehicle. The movable wall of the booster sealingly surrounds the housing of the master cylinder and acts on the housing of the booster control valve via tie rods extending axially through the end wall of the booster housing adjacent the splashboard and connected to a yoke fixed to the adjacent end surface of the housing of the booster control valve.

Abstract: To reduce the overall weight of mechanically controlled brake boosters it is known to transmit the axial reaction forces by means of axial draw bars or pipes extending axially within the booster housing. According to the present invention the weight reduction and a decrease in axial length of the brake booster is accomplished having the booster housing shaped like a ring which surrounds and is connected to the maste brake cylinder. The master brake cylinder is fastened to the vehicle splashboard via axial webs extending beyond a lateral wall of the booster housing. A yoke arranged movably between the splashboard and the booster housing contains the valve mechanism and transmits the boosting force from the booster piston (movable wall) to the piston of the master brake cylinder.

Abstract: A pneumatic servo booster includes a shell housing consisting of front and rear shells, a valve body incorporating therein a valve mechanism and sealingly extending through and being slidably supported by the rear shell, and a reinforcing plate provided on the inner surface of the rear shell. The inner circumference of the reinforcing plate is utilized to locate a seal member which is provided between the rear shell and the valve body.