Abstract: A pneumatic brake booster (10) has a booster housing (12), the interior of which is subdivided by at least one movable wall (14) into a vacuum chamber (16) and a working chamber (18). Along an axis (A) a control valve (20) for controlling a pneumatic pressure difference acting upon the movable wall (14) projects into the booster housing (12). The movable wall (14) is workingly connected to the outside of a substantially cylindrical control valve housing (22), in that a collar (34) of a plate (30) associated with the movable wall (14) is deformed along its periphery at least in sections radially into the control valve housing (22). In order to simplify manufacture of the brake booster (10), in the portion (36) of the control valve housing (22) overlapped by the collar (34) of the plate (30) a plurality of recesses (40) are provided, which are spaced apart from one another in peripheral direction and into which the collar (34) of the plate (30) is radially deformed.

Abstract: A spring brake actuator has a sealed spring chamber with a hot set large force compression spring. An alternative embodiment has the hot set spring guided by the actuator rod.

Abstract: An object of the present invention is to provide a diaphragm-type pumping apparatus which can prevent a working fluid or a fluid to be delivered from leaking through a clamping portion for clamping a peripheral portion of a diaphragm between a main body section and a casing member while preventing the peripheral portion of the diaphragm from being pulled out of the clamping portion between the main body section and the casing member during a reciprocating motion of a center rod thus to extend life-time of the apparatus.

Abstract: A dual diaphragm pump comprises a first chamber, a second chamber, a mechanical link, and a drive mechanism. The first chamber comprises a first cavity and a first diaphragm. The first chamber couples a pump inlet to a pump outlet. The second chamber comprises a second cavity and a second diaphragm. The second chamber couples the pump inlet to the pump outlet. The mechanical link couples the first diaphragm of the first chamber to the second diaphragm of the second chamber. The drive mechanism couples to the first diaphragm and the second diaphragm. In operation, the drive mechanism drives the first diaphragm causing first fluid within the first cavity to exit the pump outlet while causing second fluid to be drawn from the pump inlet into the second cavity. Further in operation, the mechanical link imparts an inlet pressure force from the second diaphragm to the first diaphragm.

Abstract: The pump of the present invention preferably includes a housing having an inlet port, an outlet port and a chamber located in fluid communication with the inlet port and the outlet port. A diaphragm is sealingly secured in the chamber and, together with the housing, define a fluid passageway from the inlet port to the outlet port. An electromagnetic assembly or other driving device is preferably secured to the housing and is positioned to move the diaphragm in order to pump fluid through the pump. In some preferred embodiments, the electromagnetic assembly includes a plunger positioned and adapted to move the diaphragm against the biasing force of a spring. Improved diaphragms and diaphragm features are also disclosed, including a two-part diaphragm structure, diaphragm sealing portions for sealing the fluid chamber from driving and biasing assemblies of the pump, and inherently biased diaphragms.

Abstract: A vest for a human body has an air core coupled to a pulsator operableto subject the vest to pulses of air which applies and releases high frequency pressure forces to the body. The pulsator has two diaphrams connected to an electric de motor with rotary to reciprocating linear motion transmitting mechanisms operable to generate air pulses in an air pulsing chamber. The diaphragms also increase the pressure in a manifold chamber. A check valve connects the manifold chamber with a pulsing chamber to allow pressurized air to flow from the manifold chamber into the pulsing chamber. An air flow control valve in commmunication with the manifold chamber is used to adjust the pressure of the air in the manifold and pulsing chambers.

Abstract: Disclosed is a diaphragm-based spring brake actuator assembly which allows for the delivery of more force to the push rod without increasing the size of the actuator unit. The invention allows for the use of a stronger heavy main compression spring in the emergency brake chamber to provide greater emergency or parking brake force to the push rod. The invention also allows the service brake chamber to operate more efficiently when braking pressure is introduced. These functions are accomplished through modifications in the design of the actuators which allow for the deployment of a larger pressure plate inside either the emergency housing or the service brake housing, or both, allowing delivery of more force to the push rod of the actuator; and are made possible in actuator units having the same dimensional profile as existing weaker units.

Abstract: An improved spring brake actuator which combines the advantages of piston and diaphragm-type brake actuators having superior performance at reduced cost. The improved spring brake actuator includes a tubular flexible diaphragm having one end secured between the rim portions of the cup-shaped housing and cover and an inverted second end portion which is received around the rim portion of a cup-shaped piston and secured in sealed relation with a flexible band. The power spring is received within opposed cup-shaped portions of the piston and cover and the rim portion of the piston is biased against a generally radial portion of the cover permitting use of a power spring having increased performance.

Abstract: An improved diaphragm-type pneumatic brake actuator wherein the diaphragm is releasably secured to the piston as the diaphragm is inverted during actuation of the braking system of a vehicle thereby reducing wear of the flexible diaphragm and improving the performance of the brake actuator. In the disclosed embodiment, a rib or lip is formed on the surface of the diaphragm which receives the periphery of the piston as the diaphragm is inverted forming a mechanical interlock between the diaphragm and the piston thereby preventing spacing of the contact surface of the piston and the central portion of the diaphragm and frictional wear between the peripheral edge of the piston and the diaphragm.

Abstract: This invention provides a sealing mechanism for sealing the piston-cylinder unit of a reciprocating diaphragm pump to ensure that the piston-cylinder unit is permanently and reliably sealed while being simple to assemble. The invention further provides a piston-cylinder unit which has almost no play in the micrometer (&mgr;m) range, and which is sealed by hydrodynamically sealing a slot thereof.

Abstract: This diaphragm support (18) for a motor vehicle brake booster comprises a central region (40) intended to be fixed to a piston (14) of the brake booster and a peripheral region (41). At least part of the support (18) extending from the central region towards the peripheral region includes a stratified structure consisting of a superposition of at least two sheets (42, 44) joined together.

Abstract: An air driven double diaphragm pump including two opposed pump chambers with an air motor having air chambers therebetween. The pump chambers and air chambers form pumping cavities divided by diaphragms. Each pump chamber includes an inlet ball valve and outlet ball valve. An inlet manifold is positioned below the pump chambers and an outlet manifold above. Tie-rods extend both across the pump from one pump chamber to the other with nuts to place the assembly in compression. Tie-rods also extend from the outlet manifold through the pump chambers, to the inlet manifold and to feet mounted therebelow. Two plates, one to either side of the air motor extend to grooves in the inlet and outlet manifold and also extend to grooves in the pump chambers so as to close of the side of the pump structure. With the plates, an outlet manifold is provided from which air may be exhausted remotely. The ball valves include small diametrical clearance and a limitation on lift for added performance.

Abstract: A motorized pump is disclosed that includes a flexible diaphragm fitting within a rigid member, a motor drive mechanism for drawing a puller member attached to the diaphragm away from the rigid member to create a space between the diaphragm and the rigid member and form a negative pressure region within that space, and an outlet communicating with the negative pressure region. In one embodiment, the pump provides a negative pressure in a single chamber which can be used to operate one or two breast shield assembles. In another embodiment, the pump is particularly adapted for double-pumping and provides two chambers which generate vacuum.

Abstract: A pump diaphragm includes a layer fabricated from polytetrafluoroethylene (PTFE) and an integral stud. In one embodiment, the stud is encapsulated within a hub assembly fabricated from PTFE and fastened to the PTFE layer with adhesive or welding, etc. In alternate embodiments, the stud may be molded in-situ with the PTFE layer using various methodology, including pressing the stud onto a heated PTFE layer. The PTFE layer then may be subjected to various forming operations to provide the diaphragm with desired dimensions and/or properties. Moreover, an additional layer or layers, such as an elastomeric layer, may be laminated onto an inside surface of the PTFE layer to provide a composite pump diaphragm.

Abstract: A leak-proof compression pump, which includes a base frame, a pressure cylinder fastened to the base frame, the pressure cylinder having a fluid chamber, a fluid inlet, and a fluid outlet, and a fluid pumping mechanism mounted in between the base frame and the pressure cylinder, the fluid pumping mechanism including an actuating member fixedly connected between the pressure cylinder and the base frame, the actuating member having an integrated semispherical diaphragm reciprocated in and out of the fluid chamber to draw fluid into the fluid chamber through the fluid inlet and to force fluid out of the fluid chamber through the fluid outlet, a reciprocating rod driven to reciprocate the diaphragm of the actuating member, and a supporting cup connected between the actuating member and the reciprocating rod for enabling the diaphragm of the actuating member to be moved in and out of the fluid chamber in the pressure cylinder.

Abstract: A hydraulic diaphragm-actuated valve has an elastic diaphragm for operation of the pressure-controlled valve, and the diaphragm includes an outer rim configured for being clamped between opposed rigid surfaces, an intermediate flexible portion connected to the outer rim, and a rigid central portion having an outside diameter extending between 0.6 to 0.8 of the radial extent of the intermediate flexible portion from the center of the diaphragm. An inner portion is integrally connected to the intermediate flexible portion, and envelopes at least a part of the rigid central portion, and serves for attachment thereto.

Abstract: A spring brake actuator (10), with a first spring brake chamber (76) filled with compressed air and a second spring brake chamber (78) housing a large-force compression spring (82), includes an elastomeric diaphragm (74) having a centrally-disposed aperture (90) separating the first and second spring brake chambers (76 and 78). The elastomeric diaphragm (74) is compressed at a peripheral edge (138) between housing sections (66, 68) and at a collar (140), which is adjacent the centrally-disposed aperture (90), between a ring-shaped retainer (142) and at least one of an actuator rod, a pressure plate (92), and an annular recess (144) in a pressure plate (92). In one embodiment, the retainer (142) includes an annular channel (154) having an inner rim (150), an outer rim (152), and a base (156). Evenly-spaced flanges (146) radiate axially from, and are separated by slots (148) on, the inner rim (150).

Abstract: An air driven double diaphragm pump including two opposed pump chambers with an air motor having air chambers therebetween. The pump chambers and air chambers form pumping cavities divided by diaphragms. Each pump chamber includes an inlet ball valve and outlet ball valve. An inlet manifold is positioned below the pump chambers and an outlet manifold above. Tie-rods extend both across the pump from one pump chamber to the other with nuts to place the assembly in compression. Tie-rods also extend from the outlet manifold through the pump chambers, to the inlet manifold and to feet mounted therebelow. Two plates, one to either side of the air motor extend to grooves in the inlet and outlet manifold and also extend to grooves in the pump chambers so as to close of the side of the pump structure. With the plates, an outlet manifold is provided from which air may be exhausted remotely. The ball valves include small diametrical clearance and a limitation on lift for added performance.

Abstract: The present invention provides a diaphragm member for use in certain valve assemblies. Such diaphragm member comprises a generally circular diaphragm having a first predetermined diameter and having a first surface and a second surface. Such generally circular diaphragm is formed from at least one layer of a preselected elastomeric material. Such generally circular diaphragm includes a nonflexing center portion, a generally annular flexure portion extending around an outer periphery of such nonflexing center portion and a non flexing outer portion extending around an outer periphery of such generally annular flexure portion, such non flexing outer portion is engageable with a body portion of such valve assembly. Such diaphragm member further includes a generally circular insert member, having a second predetermined diameter, disposed within the first surface of such nonflexing center portion of such generally circular diaphragm.

Abstract: An air bag actuated brake cylinder assembly for a railway vehicle braking system is provided which comprises a cylindrical casing engaged with the railway vehicle braking system including a hollow piston assembly having a piston rod assembly attached thereto and mounted for longitudinal movement within the cylindrical casing. An air bag actuator is engageable with the hollow piston assembly and an inner surface of the cylindrical casing for moving the piston and piston rod in an outward direction upon actuation thereof to initiate a braking sequence of the railway vehicle braking system. The air bag actuated brake cylinder assembly of the present invention allows for improved control of the movement of the brake cylinder piston and consequently improved control of the brake shoe forces which is especially desirable during light load conditions. Also, the air bag actuated brake cylinder of the invention is capable of accommodating piston bail and/or misalignment without leaking air.

Abstract: A diaphragm pump, especially a microdiaphragm pump, with a crank drive (1) having a connecting rod (2) and an elastic diaphragm (3) connected with the connecting rod (2) has on the back side of the diaphragm facing away from the compression chamber at least one undercut fastening opening (8) for insertion of the complementarily formed attachment end of the connecting rod. In order to be able to fix the diaphragm (3) so precisely on the connecting rod (2) that radial as well as axial forces do not move it from its position relative to the connecting rod (2), and in order that the diaphragm (3) is exposed to as little additional flexing work as possible, the connecting rod (2) is provided on its attachment end with a support surface (4) for underside support of the central diaphragm area having a bearing surface (5).

Abstract: A diaphragm (1) for a diaphragm pump consists of a resilient material having a substantially annular outer region of a relatively low thickness and an adjacent central region which becomes thicker radially towards the center. A solid molded core (3) is vulcanized in the central region, for connection with a pump drive part. An outer diameter (F) of the core is less than a third of the outer diameter (D) of the diaphragm, and the thickness (L) of the resilient material of the central region above the solid core is between 5% and 20% of the outer diameter of the diaphragm. The diaphragm is used to avoid undesirable deformation of the diaphragm, during a tilt transmitted from the drive to the solid core, on both sides of top dead center. This diaphragm produces a pump with a low clearance volume and a large compression ratio.

Abstract: A combination pump diaphragm and outer piston arrangement used in certain pump applications in which at least a portion of such diaphragm is in contact with an outer piston which would tend to abrade the diaphragm. The combination comprises a diaphragm member which includes a generally flat portion, a generally flexure annular portion and an enlarged bead like wear ring portion disposed intermediate such generally flat portion and such generally flexure annular portion. Such bead like wear ring portion has a first predetermined diameter and a predetermined configuration. The outer periphery of such diaphragm member is secured to a pump housing. An outer piston member is disposed for securing such diaphragm member to a piston rod of a pump. Such outer piston member includes a generally flat portion contacting such generally flat portion of such diaphragm member and an arcuate portion contacting such enlarged bead like wear ring portion.

Abstract: In a conventional spool valve, the nut holding the diaphragm to the spool valve stem is replaced by a retaining ring, thereby simplifying the machining operation and eliminating the problems caused by damaged threads. A good seal is nevertheless achieved by providing an insert molded diaphragm having a bead around its axial aperture, which is compressed against the radial flange of the valve stem, and such that the retaining ring will maintain the compressed condition of the bead against the radial flange to maintain a good seal.

Abstract: In a diaphragm pump apparatus having a first chamber and a second chamber divided from the first by a movable diaphragm, the diaphragm comprises on both sides annular surfaces, whereby the annular surface is rounded out and goes over into a conically tapering thickened area and the other annular surface is provided with a concavely curved rounded-out portion incorporated into the thickened area of the diaphragm. By means of this design it is achieved that even highly viscous media can be pumped with the diaphragm pump apparatus, that the diaphragm has a long lifespan and that trouble-free operation of the diaphragm pump apparatus is ensured.

Abstract: The present invention provides a combination disc diaphragm assembly which comprises a disc portion having a first configuration and includes a round center portion having a first diameter and a first thickness. It further includes a round outer portion connected to and extending outwardly from an outer periphery of such center portion adjacent a bottom surface. The outer portion has a second diameter which is greater than such first diameter. The outer portion has a second thickness which is less than the first thickness. The disc also has a domed shaped cavity formed in the bottom surface and having a first radius. There is a diaphragm member having a second configuration and a third diameter which is greater than the second diameter of the disc. The diaphragm has a first side with a dome shaped projection disposed on a center portion. The domed shaped projection has a second radius. The first side of the diaphragm has a generally flat surface adjacent the dome shaped center.

Abstract: A two-ply pressure plate (36) for use in an air brake system (10) for a vehicle, such as a bus, truck or the like, is shown. The two-ply pressure plate (36) includes a diaphragm plate (92) which abuts a diaphragm (32) of an air brake system (10) and a support plate (98) which abuts the rear surface of the diaphragm plate (92). A control rod (18) is welded to the support plate (98) and diaphragm plate (92). Some form of mechanical or metallurgical interconnection between the support plate (98) and diaphragm plate (92) is formed in between the mounting point of the rod (18) and the outer perimeter of the smaller of the two plates.

Abstract: An air-operated diaphragm spring brake actuator has a pressure plate formed entirely of plastic. The diaphragm is secured to the pressure plate by ultrasonic welding. The pressure plate also has a central hub which centers the opening and receives the actuator rod in press-fit engagement.

Abstract: Brake actuators are provided with self-centering diaphragms. In one embodiment, the diaphragm is provided with a centering bead radially outwardly of a sealing bead. The centering bead ensures the diaphragm is properly centered prior to the brake actuator housings being secured together. In a second embodiment, the self-centering structure includes structure fit into mating structure in one of the brake actuator housings to ensure the diaphragm is properly centered. The self-centering structure ensures the brake actuator diaphragms are properly centered before connection of the two brake actuator housings. This invention is particularly useful in the type of brake actuator housings having deformed housing portions.

Abstract: A diaphragm assembly has a center disk in which use of a metal member is not required. The center disk comprises first and second center disk members, made of resin, embracing a resin diaphragm between them. The first center disk member has an inwardly directed inner flange on an inner peripheral wall defining a resin charging space, and the second center disk member comprises a resin-molded body, formed by charging a resin, and has an outwardly directed outer flange. A portion of the diaphragm is clamped between the inner flange and the outer flange.

Abstract: A valve assembly 30 having a pressure balancer 38 disposed in a housing 32 in which is formed a chamber 48. A one-piece poppet unit 46 is mounted for movement in the chamber 48. The poppet unit 46 has a shaft 51 with a circular disc 106 to which is bonded a diaphragm 56 and a pair of poppets 52 and 54 formed at either end thereof. The diaphragm 56 divides the chamber to form a compartment on either side thereof in which there is zero leakage across the diaphragm 56 of the poppet unit 46 and eliminating any cross-flow leakage between the hot and cold water, respectively, in the chamber compartments.

Abstract: For the purpose of routing an electric cable through the movable wall of the two pneumatic working chambers of an electronically controllable bake booster, comprising a first pneumatic working chamber and a second pneumatic working chamber which are separated by a movable wall, where a simple assembly and a high functional reliability are to be ensured, a cable feed-through for at least one electric cable penetrating the movable wall is provided, with a portion of the cable-feed through penetrating the movable wall, and a holder which limits the movability of the cable feed-through at least in its longitudinal direction, and a seal surrounding the cable feed-through in the area of the movable wall.

Abstract: An insert member for use in a flexible diaphragm portion of a pump which enables such flexible diaphragm portion of such pump to be provided with a substantially uniform non-obtrusive surface area that will be positioned in such pump for intimate contact with a material to be pumped. Such insert member includes a first disc-like portion having both a first predetermined size and a first predetermined configuration. There is also a second disc-like portion having both a second predetermined size and a second predetermined configuration. The second disc-like portion is secured adjacent one surface thereof to a first surface of the first disc-like portion and such second disc-like portion extends from the first surface of such first disc-like portion for a predetermined distance. This second disc-like portion is disposed substantially in a center portion of the first surface of such first disc-like portion.

Abstract: Inert plastic coated flexible diaphragm for sanitary pump applications includes a first body portion, disposed in center of diaphragm, which is relatively thick and exhibits a first degree of flexibility. A second body portion is formed contiguously with the first body portion and extends around periphery thereof. The second body portion is relatively thin, compared to the first body portion, and exhibits a second degree of flexibility greater than the first degree of flexibility. A sealing bead-like member is formed contiguously with such second body portion and extends around periphery thereof for sealing the flexible diaphragm in an operating position within a housing portion of such pump. A flexible plastic layer is adhered to each surface of the first body portion, the second body portion and such sealing bead-like member which will come into intimate contact with a material to be pumped. Such plastic layer having a substantially uniform thickness.

Abstract: A diaphragm pump (1) with a working diaphragm (16) is provided with an additional diaphragm (26) arranged at a distance (a) from the working diaphragm (16), between the working diaphragm and eccentric drive (7). The diaphragm pump (1) provided with an additional diaphragm may alternatively have a swing connecting-rod with U packing ring instead of the working diaphragm (16). The additional diaphragm, together with a lateral confinement formed by an intermediate casing (4) of the pump case (2), composes an essentially closed diaphragm interspace. A deformable annular zone (30) of the additional diaphragm (26) has a channel-like convexity (31) which, in the undeformed condition of the diaphragm, points in the direction of the eccentric drive (7). For this purpose, the elastically deformable annular zone (30) of the additional diaphragm (26) has a radial expanse wider than the deformable annular zone (24) of the working diaphragm (16).

Abstract: In a diaphragm actuator in which a central boss provided in a retainer plate is passed through a central opening of a diaphragm, to prevent any excessive stress or deformation developed in a freely deformable part of the diaphragm from being transmitted to the central opening fitted on the central boss, and adversely affecting the condition of coupling between them, a plurality of through holes are provided in the retainer plate so that, when vacuum is suddenly introduced into a vacuum chamber of the diaphragm actuator, the diaphragm is firmly secured to the retainer plate by suction produced by the through holes.

Abstract: A diaphragm assembly for movement in response to a pressure increase exerted thereon comprised of a resilient flexible diaphragm having a first surface with a predetermined profile when said diaphragm is in a neutral, unflexed condition, the diaphragm having an opening formed therethrough.A rigid pressure plate is adapted to be positioned against the diaphragm. The plate has a contoured surface for mating engagement with the first surface of the diaphragm. The contoured surface has a recessed sealing surface dimensioned to form an open space between the plate and the diaphragm when the diaphragm is in the neutral, unflexed condition, and to enable the diaphragm to flex into sealing engagement therewith when sufficient pressure is exerted on said diaphragm. A first vent passage communicates the opening in diaphragm with the open space, and a second vent passage communicates the open space with the edge of the pressure plate.

Abstract: An improvement of an axial portion of a power piston and a retainer engaging therewith for a booster. An axial portion of the power piston is formed with a first tubular portion, which is provided with a second tubular portion located outward of the first tubular portion. The first tubular portion is fitted over a flange of a valve body from the rear side, and an annular retainer engages the second tubular portion from the front side, thereby securing the axial portion of the power piston, which is formed with the both tubular portions, on the flange of the valve body. The retainer includes a plurality of engaging pawls, which engage the outer peripheral surface of the second tubular portion of the power piston by point contact. This reduces the axial size of the valve body, and hence the axial size of the booster.

Abstract: A membrane supporting plate (10) includes on its outer rim (20) an axially directed ring groove (30), into which an annular membrane (22) is inserted, free from distortion, by its clamping boss (28) disposed on its inner rim. A beaded rim (32) disposed next to the ring groove (30) on the membrane supporting plate (10) is deformed radially outwards by a beading process. As a result of the effected sealing of the ring groove (30), the membrane (22), which is made from highly elastic material, is anchored pressure-tight and free from distortion to the membrane supporting plate (10).

Abstract: A fluid-operated spring brake actuator has a funnel-shaped pressure plate which reduces the volume of fluid necessary to compress the spring and release the brake thereby providing a faster response time upon actuation of the brake.

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

Abstract: To preclude a rolling diaphragm forming together with a metallic diaphragm plate the movable wall of a vacuum brake force booster from being detached from a groove accommodating the radially inward area of the rolling diaphragm, it is provided, in the practice of the invention, that the contour of a supporting face for the diaphragm plate formed on the control valve housing and the contour of the radially inward area (sealing bead of the rolling diaphragm correspond to the curved shaped of the radially inward area (curvature) of the diaphragm plate, and that both the contour of the supporting face and the one of the radially inward area (sealing bead) of the rolling diaphragm correspond to the curved shape of the radially inward area (curvature) of the diaphragm plate, and that the groove with the axial dimension thereof extends into the bearing area of the diaphragm plate of the support face.

Abstract: A vacuum brake power booster and a process is disclosed in which a precise adjustment of the power boost startup characteristic is achieved. The adjustment is carried out as a final step in the manufacture of the booster adjusting the distance between the valve piston and an elastic reaction distance. During adjustment, the vacuum brake power booster has a vacuum applied. A pre-established input force is exerted on the piston rod while simultaneously measuring the output force exerted by the push rod, and the axial length of the valve piston is modified until the measured output force is within a pre-established range. The adjustment is carried out by modifying the length of a two piece valve piston or by temporarily extending a rod within the valve piston until a correct output force is reached and thereafter removing the rod and inserting a transmission pin of a length determined by the extent of travel of the rod at the point at which the desired output force was attained.

Abstract: A pneumatic control drive 1, 51, 71 for control devices, in particular control valves, comprises a drive housing 5 and a drive member 11 displaceable therein and to which is affixed a drive element 18 displaceable together with said drive member 11 to actuate the control device and exiting the drive housing 5, said drive member dividing the drive housing 5 into a pressure chamber 12 and a reset chamber 13 with a reset member 15, 16 loading the drive member 11. A position controller 3 is adjacent to one of the chambers (13) and communicates through an inner air-supply duct 30, 28, 55, 74 with the pressure chamber 12, a vent duct 35, 58, 76 issuing from the reset chamber 13 toward a vent aperture. In the invention, the drive element 18 comprises an air-supply duct 24, 25 issuing at the side of the drive member 11 away from the position controller 3 into the pressure chamber 12 there.

Abstract: The invention relates to a pneumatic brake-booster comprising a casing (10), inside which is situated a piston (20) comprising a rear tubular part (22) and a movable wall (12) defining a front chamber (16) permanently connected to a vacuum source and a rear chamber (18) selectively connected to the front chamber (16) or to the atmosphere by a valve mechanism (20a, 32a, 40) actuated by a control rod (34) adapted to bear, by way of a plunger (32) against one face of a reaction disk (58) fastened to a push rod (56), the valve mechanism comprising a valve closure member (40) cooperating by an active part with a first valve seat (32a) formed on the plunger (32) and with a second valve seat (20a) formed on the piston (20). According to the invention, a guide mechanism (62) for the air in movement are provided upstream of the valve mechanism.

Abstract: In a tandem type vacuum booster, the inner peripheral end of a front booster piston and the inner peripheral bead of a front diaphragm are clamped between a front end of a sleeve fitted over the outer periphery of a piston boss and a flange provided on the piston boss and are thereby fixed to a front portion of the piston boss, while the inner peripheral end of a rear booster piston and the inner peripheral bead of a rear diaphragm are clamped between a stopper member mounted on the piston boss and a rear end of the sleeve and are thereby fixed to a rear portion of the piston boss. A first port for communicating the front and rear working chambers with the control valve, and a second port for communicating the front and rear vacuum chambers with the control valve extend through both the piston boss and the sleeve, and communication between both the ports is inhibited by a single annular sealing member mounted at an axially intermediate portion of a junction surface between the piston boss and the sleeve.

Abstract: An improvement of a reaction transmitting mechanism for a booster is disclosed. A forward end face of a tubular portion of a valve body which abuts against a reaction disc is provided with an uneven surface. This presents a resistance to an elastic deformation of the reaction disc when a brake booster is actuated. Accordingly, an enhanced hysteresis, which represents a difference in the output between when depressing and releasing a brake pedal, is provided without increasing the hardness of the reaction disc.

Abstract: A vacuum booster has a booster shell formed of a front shell half and a rear shell half interconnected at their open ends opposed to each other, and a diaphragm which divides the shell interior into a vacuum chamber on the front shell half side and a working chamber on the rear shell half side. An outer peripheral bead portion of the diaphragm is clamped between the open ends of both the shell halves with an outer surface of the outer peripheral bead portion being contacted under pressure with an inner surface of the open end of the front shell half. The outer peripheral bead portion is provided at an outer periphery thereof with a first tapered surface tapered toward the front shell half and a second tapered surface tapered toward the rear shell half such that the first and second tapered surfaces are formed into an angled shape in their cross section.

Abstract: An actuator (1) of a diaphragm type which comprises an actuator case (2,3), a diaphragm (5) housed in the actuator case, a diaphragm plate (4) attached to the diaphragm for moving together with the diaphragm according to introduction of negative or atmospheric pressure into a negative pressure chamber (7) formed between the diaphragm and the actuator case (2) so as to actuate a device connected to the diaphragm plate. The diaphragm is formed with one or both of an annular rib (5e) having a thick-walled section and an annular expansive portion (5d) having a curved section. Therefore, the diaphragm is hard to be disengaged from the diaphragm plate even if an immoderate force is applied on the diaphragm.