Abstract: A slack adjuster for axially moved push rods is provided. An axially extending rotating actuating shaft turns a helical, driving cam member that in turn axially displaces a non-rotating driven cam member. The driving and driven helical cam members are located in a housing with the actuating shaft extending out of one end thereof and a threaded push rod extending out of the other end of the housing. A helical return spring is positioned between the driven cam and the inner wall of the housing to bias the cam members together. The push rod is held against rotation internally of the housing by a flange whose periphery is frictionally engaged by the return spring. A nut is threaded onto the rod and engaged by the driven cam member to transmit axial force to the push rod; and relative extension of the push rod from the cam members is accomplished by a one way spring brake acting on the nut and a disc clutch drive between the driving cam and nut.

Abstract: The invention consists of a slack-adjuster for a brake which comprises a pair of interengaged screw threaded members which are urged towards an extended relative position by an axial bias applied to one member. The screw thread has a high helix angle to permit adjustment to take place on release of the brake and reverse rotation is prevented by frictional engagement of the leading member with a brake applying plunger part and by the use of a saw-tooth screw thread.

Abstract: A brake unit for automatically adjusting slack between the brake surfaces of a railway brake has a pre-stressed spring which is released during the initial stroke of the brake piston in a braking application so as to expedite contact of the brake surfaces. After slack has been overcome, further movement of the piston in the braking direction will cause the force-transmitting components to be coupled together so that braking force is transmitted directly to the brake surfaces by subsequent movement of the piston in the braking direction. The release of the pre-stressed spring during the overcoming of slack in the brake rigging will increase the speed of the brake application with respect to the speed of the braking piston.

Abstract: The invention pertains to an automatic brake slack adjuster wherein incremental vehicle brake adjustments are automatically produced as brake lining wear occurs. The novel features include the simplification of structure, the provision of preadjustment including a drive gear which is automatically disengaged from a worm gear upon the placing of a wrench upon an adjustment shaft to simplify preadjustment, and a universal bracket is utilized permitting the adjuster to be readily employed with a wide variety of vehicle brake rod structures eliminating the need for special fittings and modifications.

Abstract: The adjuster has a clutch mechanism operative between an actuator piston and an auxiliary mechanical actuator. The clutch mechanism includes a first member and a second member, one of the members being connected to the actuator piston for axial movement therewith at all times in both directions and the other of the members being connectible with the mechanical actuator. The one member is free to move back and forth with the actuator piston during normal service brake applications, the other member not hindering its movement. Also, the other member is only moved to engage the one member upon actuation of the mechanical actuator. Thus the actuator piston is free to move back during "knockback" and normal braking is not hindered by the clutch mechanism.

Abstract: An internal shoe-drum brake is disclosed in which a pair of arcuate shoes can be applied to a rotatable drum by an hydraulic actuation system for normal service braking when the brake acts as a brake of the "two-leading" shoe type and a mechanical actuation system for parking or emergency braking when the brake acts as a brake of the "duo-servo" type. The hydraulic system comprises two hydraulic pistons, each of which acts on the leading end of a respective shoe, and first and second abutments are provided against which the trailing ends of the shoes are adapted to rest. One abutment is fixed but the other abutment includes an auxiliary hydraulic piston which is adapted to be urged against a fixed stop by hydraulic pressure applied to the pistons. The reaction from the trailing end of a respective shoe tends to urge the piston away from the stop, but the area of the piston is sufficient to prevent this happening when the hydraulic pressure is acting on the piston.

Abstract: A disc brake comprises an operating piston mounted in a cylinder rigid with a stirrup. The piston is movable in the cylinder to cause axial movement of friction linings under the action of hydraulic pressure or the force of a mechanical brake actuator. An operating clearance is provided to allow a limited retraction of the friction linings when the hydraulic pressure or the mechanical actuating force is released. The mechanical actuator comprises a screw rotatable in the cylinder. A nut engaged by the screw is connected to the piston by a unidirectional coupling device comprising teeth on the nut co-operating with teeth on a ring fixed for rotation with the piston. The nut is mounted for translatory movement in relation to the piston solely through a limited distance corresponding to the operating clearance, and the ring is mounted for axial displacement relative to the piston.

Abstract: A single-acting, clearance sensing slack adjuster for brakes is provided. The slack adjuster includes a displaceable brake actuation assembly (28), a rotatable driving member (52), a rotatable intermediate member (60) and a rotatable driven member (56). The driven member is in driving relationship with a rotatable adjustment member (50) which is rotatable in a given direction to advance a brake friction member (32) to maintain the running clearance (38) within predetermined limits. A linear to rotational motion assembly (76-80) is provided to rotate the driving member in the slack decreasing direction of rotation in response to greater than predetermined movement (82) of the brake actuation assembly. A first coil clutch (20) couples the driving and intermediate members while a second coil clutch (72) couples the intermediate and driven members.

Abstract: The actuating device comprises an actuating nut and spindle combination disposed in a brake piston, the spindle being rotated by an actuating lever and the nut having an outer thread engaging an inner thread of the brake piston thereby providing a brake pad clearance adjusting device. The brake piston is rotatably connected to the spindle via a one-way clutch for progressively screwing the brake piston out of the nut to compensate for brake pad wear. The one-way clutch is connected to the spindle by a rod extending through an axial bore in the spindle enabling the clutch to be unlocked from the outside of the actuating device for resetting the brake piston when worn brake shoes are being replaced.

Abstract: An automatic slack adjuster (10) having a lever housing (30) containing interior components to be lubricated and defining a first bore (36) in which a worm gear (38) is received, a second bore (42) intersecting the first bore in which a worm (44) and worm shaft (52) are received and a third bore (54) in which a drive mechanism (72 & 66) for rotating the worm shaft is received is provided. A lubricant fitting (150) is provided into the first bore and a passage (152) is provided between the first and third bore. Seals are provided to seal the exterior openings of the bores. The passage (152) defines in part a lubricant path between the fitting and the exterior opening (73) to the third bore which is configured so that the resistance to the flow of lubricant from the fitting (152) to the exterior opening (73) of the third bore is greater than the resistance to the flow of lubricant between the fitting and any other interior component to be lubricated.

Abstract: A disc brake is provided with a fluid pressure operating mechanism for a service brake and concurrently with a mechanical operating mechanism for a parking brake. A parking lever of the parking brake is connected to an adjusting bolt through a spindle and a connecting link and further connected to a piston slidable in a cylinder through a sleeve nut. The adjusting bolt is prevented from rotation by a stopper plate fixed to the cylinder. The adjusting bolt and the sleeve nut are connected by thread and provided therebetween with a stopping means of rotation which allows a forward rotation of the sleeve nut toward a disc but limits a retracting rotation of the sleeve nut from the disc. The stopping means of rotation is provided with a locking means which effectively prevents a retraction of the sleeve nut. A clearance between friction pads and the disc is automatically adjusted by the fluid pressure operating mechanism when linings of the friction pads are worn more than a predetermined amount.

Abstract: An improved slack adjuster (10) of the clearance sensing type for brakes of the type having a running clearance adjustable by controlled rotation of a shaft (52) such as cam (14) actuated brakes. The slack adjuster includes a one-way drive mechanism including a spring clutch (86) wrapped around the ends of a driving shaft (62) and a driven shaft (52) which is adapted to slip when the torque necessary to rotate the driven shaft exceeds a predetermined limit. The surface (138) of the driven shaft under the spring clutch is provided with a deposit (142) of material different from the remainder of the shaft which will improve the wear and/or frictional characteristics of the surface. The improvement comprises providing a shoulder (148) at the end (146) of the surface of the driven shaft closest the driving shaft which has been found to improve the resistance of the deposit to chip and/or separate from the shaft during assembly and/or use.

Abstract: An auto-adjusting mechanism in a disc brake comprising axially movable adjust bolt, adjust nut threaded on adjust bolt, cylindrical piston for transmitting the operating force of a pad-urging-piston to the adjust nut when the piston has moved beyond a predetermined value, spring structure for biasing cylindrical piston toward adjust nut. The cylindrical piston is integrally moved, while the wearing of the brake pads is insignificant, with the piston, but when the wearing has progressed largely, it is abutted on the adjust nut to be separated from the piston, with a result of leaving the thrust force from the spring structure act solely on the adjust nut and rotatingly propelling the nut for compensating the increased brake clearance. And this cylindrical piston is, when the braking fluid pressure in the cylinder body is raised beyond a predetermined value, separated from the adjust nut overcoming the urging force of the spring structure. The over adjustment is prevented in this way.

Abstract: An improved drum brake adjuster includes an adjustable strut with threadably engaged parts disposed between a pair of brake shoes to maintain a controlled spacing between the brake shoes. The adjuster includes an extendible member engaging one of the brake shoes and extending to lengthen the strut in response to the force of an adjusting spring. A pivot member engages the extendible member and the other brake shoe. The adjuster also includes a resilient member and a clutch device disposed between the extendible member and the pivot member. The resilient member and the clutch device cooperate to prevent change in the length of the strut unless brake lining wear occurs.

Abstract: A drum brake includes a pair of brake shoes which are carried by and pivotally anchored to a backing plate. The pair of shoes are engageable with a brake drum to effect a brake application. A running clearance is maintained between the brake shoes and the drum when the brakes are released by an adjusting member which includes an adjusting lever pivotally carried by one of the shoes and a fixed-length spacer carried between the adjusting lever and the other brake shoe. An extensible member is carried between one end of the adjusting lever and the one brake shoe and a three-bar linkage effects an extension of the member to compensate for wear of the brake shoes. The adjusting lever forms one bar of the linkage and carries the other two bars. The second bar of the linkage is pivotally engaged with the adjusting lever and with the spacer and is biased so as to move the spacer away from the adjusting lever during a brake application.

Abstract: The hydraulic activators are provided with a relief valve which serves to permit communication between the disengaging cylinder chamber and the work cylinder chamber. The open position of the relief valve occurs when the release apparatus for the rotatable friction brake member is closed. The closed position of the relief valve occurs after the rotating brake is released. The relief valve can be mounted in the release apparatus of the working piston.

Abstract: Slack adjusting means comprises a linearly movable input member, a linearly movable output member, and an element for transmitting a brake force from the input member to the output member, characterized in that the input and output members are constrained against relative angular movement, and in that the element is engaged with one of said members via co-operating helical thread means provided therebetween and is engageable with the other of said members via co-operable clutch faces provided therebetween and arranged such that in use the clutch faces are retained in force-transmitting engagement by the reaction forces in the co-operating helical thread means and are disengageable when said reaction forces are removed or relieved thereby to permit relative rotation, and hence relative linear displacement corresponding to the slack to be taken up, between the element and said one member in engagement therewith via the co-operating helical thread means.

Abstract: A disc brake including a hydraulic actuator and a mechanical actuator is disclosed. The hydraulic actuator comprises a piston and the mechanical actuator comprises a push rod adapted to engage said piston through a self adjusting device, said adjusting device including a nut received on a threaded rod associated to said push rod, a thrust bearing capable to rotate said nut relative to said push rod on movement of said piston in a brake applying direction, and a clutch spring adapted to prevent rotation of the nut in the opposite direction. The thrust bearing comprises a cage which cooperates with the piston through a circumferential lost-motion connection adapted to limit rotation of said nut relative to said threaded rod to a predetermined angle on each hydraulic brake application.

Abstract: An automatic clearance adjuster for a cam actuated vehicle brake. The adjuster is disposed in a pivotal lever and includes a worm and worm gear, an adjusting mechanism for effecting a clearance decreasing rotation of the worm during the brake apply stroke, a torque limiting ratchet clutch which slips to prevent rotation of the worm by the adjusting mechanism when the shoes are in contact with the drum during the brake apply stroke, and a roller clutch which prevents clearance increasing rotation of the worm by the adjusting mechanism during the brake release stroke.

Abstract: A one-nut slack adjuster with a nut axially disposed having clutch surfaces and on non-self-locking engagement on a spindle coaxially positioned within a tube moving axially to apply brakes has a spring biased thrust bearing held forwardly on the nut in the brake application direction disposed to engage a fixed position control member and when the nut is moved axially forwardly a predetermined desired slack distance thereby to bias the nut backwardly. A second trust bearing on this nut is placed forward of the control member to engage it at a distance from rest less than the clutch separation distance.In a double acting embodiment a further trust bearing spring biased between the nut and tube in a position forward of the control member holds the nut in a forward direction in clutch engagement.A further feature is a barrel spring arrangement foreshortening the assembly by a sleeve converting two coaxially disposed spring sections in series.

Abstract: An automatic clearance adjuster for a cam actuated vehicle brake. The adjuster is disposed in a pivotal lever and includes a worm and worm gear, an adjusting mechanism for effecting a clearance decreasing rotation of the worm during the brake apply stroke and a clearance increasing rotation of the worm during the brake relesase stroke, a two-way torque limiting ratchet clutch which slips to prevent rotation of the worm by the adjusting mechanism when the shoes are in contact with the drum, and a roller clutch which allows a predetermined amount of clearance increasing rotation of the worm by the adjusting mechanism and then locks up and causes slippage of the torque limiting clutch to prevent further clearance increasing rotation of the worm.

Abstract: A brake cylinder device for railway vehicles including a built-in automatic slack adjuster and a manually axially positionable piston for resetting the piston and piston rod relative to the slack adjuster when necessary, such as when replacing worn brake shoes, the piston rod being interconnected through a nut and screw, friction clutch, and a key to a manually rotatable member, which, when rotated causes axial displacement of the piston rod and piston to desired adjusted position relative to the slack adjuster.

Abstract: An automatic clearance adjuster for a cam actuated vehicle brake. The adjuster is disposed in a pivotal lever and includes a worm and worm gear, an adjusting mechanism for effecting a clearance decreasing rotation of the worm during the brake apply stroke and a clearance increasing rotation of the worm during the brake release stroke, a two-way torque limiting ratchet clutch which slips to prevent rotation of the worm by the adjusting mechanism when the shoes are in contact with the drum, and a roller clutch which allows a predetermined amount of clearance increasing rotation of the worm by the adjusting mechanism during the brake release stroke and then locks up and causes slippage of the torque limiting clutch to prevent further clearance increasing rotation of the worm.

Abstract: In an automatic slack adjuster for a vehicle brake, an adjuster member acts on a part of an adjustable strut assembly for maintaining a substantially constant braking clearance between a braking member and a rotatable braking surface, the adjuster member acting on the part through a driven ring, and an overload spring urges a clutch face on the driven ring into engagement with a complementary clutch face on the part so that the driven ring and the part are movable together unless the reaction between the clutch faces exceeds the loading of the overload spring whereafter the driven ring can rotate relative to the strut assembly to preclude adjustment.

Abstract: A hydraulic actuator for a vehicle brake system is provided with an auxiliary mechanical actuator e.g. a handbrake cam which is fitted to a first component (e.g. a first piston) of the hydraulic actuator and acts through an automatic slack adjuster on a second component (e.g. a second piston) of the hydraulic actuator. The adjuster comprises a rotatable push rod and a non-rotatable nut with a screw-thread connection therebetween. The rotatable push rod has a portion which is sealed to the first piston and upon which the mechanical actuator acts.

Abstract: In a brake cylinder there is a reciprocating piston from which extends a non-rotatable sleeve surrounding a co-axial non-rotatable axially displaceable threaded shaft upon which is threaded a coupling nut. A pair of rotary couplings are provided on opposed sides of the coupling nut with the sleeve and the rotary couplings are actuable by axial displacement of the coupling nut. A stop ring is axially displaceable on the coupling nut and is supported opposite to the braking direction by a fixed stop. A second stop on the coupling nut is spaced rearwardly of the first stop a distance approximately equal to the contact stroke of the vehicle brake when the resetting device is in the inoperative position. To provide for single acting operation, the resetting device is provided with a spring which has one end acting against the stop ring and the other end acting against an abutment on the sleeve.

Abstract: In a brake cylinder there is a reciprocating piston from which extends a non-rotatable sleeve surrounding a co-axial non-rotatable axially displaceable threaded shaft upon which is threaded a coupling nut. A pair of rotary couplings are provided on opposed sides of the coupling nut with the sleeve and the rotary couplings are actuable by axial displacement of the coupling nut. A stop ring is axially displaceable on the coupling nut and is supported opposite to the braking direction by a fixed stop. A spring has one end acting against the stop ring and its other end acting against an abutment on the sleeve. A second stop on the coupling nut is spaced rearwardly of the first stop a distance approximately equal to the contact stroke of the vehicle brake when the resetting device is in the inoperative position.

Abstract: A brake adjuster mechanism is of the type operable by a piston moving a threaded spindle axially during braking with a threaded nut thereon adjusting the spindle position. Two control members movable with the spindle are held apart by a spring between shoulder stops on the nut and they serve to position the nut between two opposed clutch surfaces to permit nut rotation until a predetermined slack setting is achieved.

Abstract: This invention relates to a pneumatically-applied spring-released brake assembly for each individual wheel of a railway vehicle truck, wherein the brake assembly comprises a pair of levers that so cooperate with non-self-locking threads formed on a nut and a screw member as to provide a high mechanical advantage or multiplication of the braking force transmitted from a piston to a brake shoe thereby enabling a substantial reduction in the diameter of the piston and therefore of the size of the brake assembly from that of such assemblies heretofore necessary to transmit the same braking force to the shoe.

Abstract: The adjusting device includes a threaded spindle onto which an adjusting nut is screwed, a frictional-engagement turning mechanism for the adjusting nut, a brake for preventing a turning movement of the adjusting nut and a resilient connection between the turning mechanism and the working piston. The brake is formed by two seal lips of a sealing arrangement stationarily connected with the working piston, the two seal lips abutting in a sealed relation against the adjusting nut and acting in opposite directions.

Abstract: A combined hydraulically operated service and mechanically operated parking brake of the disk type. The components are arranged to provide an extremely compact assembly that may be fit into existing vehicles. The mechanical actuator includes a roller type cam mechanism with an externally actuated operating lever. The mechanism is constructed to provide a minimum number of seals and a lip type seal is embodied that will provide a ready indication on test if the seals of the hydraulic portion of the brake are defective. An improved automatic adjustor interconnects the mechanical actuator with the piston of the hydraulic brake to adjust for wear of the brake linings. The automatic adjustor includes a differential screw mechanism and one-way brake that operates to effect automatic adjustment in the event of overtravel during brake application.

Abstract: The present invention refers to an automatic slack adjuster to regulate the slack between a rotating disc that is secured to a railroad car axle, and a braking element which is brought into contact with the rotating disc, to brake it. The slack adjuster is inserted in a pneumatic brake cylinder. This brake cylinder includes at least one piston the purpose of which is to move axially when the cylinder is activated, and a driving shaft or piston rod connected with the braking element.

Abstract: An automatic slack adjuster for a vehicle brake is disposed between a piston and another component, such as a counter piston, of a hydraulic actuator. The adjuster mechanism is housed in an encapsulating container which is positively attached to the piston. A strut, on which an auxiliary mechanical actuator fitted to said other component acts, is in screw-threaded connection with a nut of the adjuster mechanism. The adjuster mechanism is of the incremental type and is adapted to turn the nut responsively to excess axial travel between the container and the strut upon hydraulic brake application, the strut being sealed to said other actuator component. Grossly excessive travel between the piston and the other actuator component beyond the maximum possible travel between the strut and the container is permitted by displacement of the strut relative to said other component.

Abstract: A fail-safe actuator for a disc brake system. A housing contains a reciprocating piston having a retracted position, a spring which urges the piston forward away from its retracted position, and means for retracting the piston against the urging of the spring. An expansible linkage, which connects the piston to the friction element of the brake is expanded in response to retraction of the piston, thereby maintaining a uniform spring expansion per brake application regardless of friction element wear.

Abstract: A disc or drum brake fluid pressure actuator incorporates a lock actuator strut acting on an inner part of a telescopic piston assembly, of which the inner and outer parts are normally rendered effectively unitary by pre-stressed spring which can, however, deflect under excess pressure to permit extension of the lock actuator strut when it is desired to operate the strut for parking purposes. An hydraulic control system for operating the actuator is also described and illustrated.

Abstract: An internal shoe-drum brake in which arcuate shoes carrying friction linings for engagement with a rotatable drum are mounted on a stationary back-plate and the shoes are separated at one end to bring them into engagement with the drum by a service actuator for normal service braking and at the other end by a mechanical parking actuator. Abutments are provided at or adjacent to the mechanical parking actuator to take the braking loads when the brake is applied by the service actuator, and means are provided in or adjacent to the service actuator for transmitting servo braking forces from one shoe to the other when the brake is applied by the mechanical parking actuator. An actuating member is operative to actuate the parking actuator to release energy stored therein thereby applying continuously to the shoes a force to urge them into engagement with the drum irrespective of the initial position of the shoes when the actuating member is operated.

Abstract: A single acting pneumatic brake assembly is constructed to permit the push rod to be returned by external force when brakes are replaced, and the like. Thus, two pairs of clutch surfaces are both disengaged while the push rod is returned by pressure applied between a stationary part and a movable member of the assembly such as the push rod and wheel. A movable clutch member holds the clutch surfaces open during return of the push rod. A spring holds one clutch surface closed until overcome by pressure to return the push rod.

Abstract: An automatic slack adjuster for a vehicle brake is disposed between a piston and another component, such as a counter piston, of a hydraulic actuator. The adjuster mechanism is housed in an encapsulating container which is positively attached to the piston. A strut, on which an auxiliary mechanical actuator fitted to said other component acts, is in screw-threaded connection with a nut of the adjuster mechanism. The adjuster mechanism is of the incremental type and is adapted to turn the nut responsively to excess axial travel between the container and the strut upon hydraulic brake application, the strut being sealed to said other actuator component. Grossly excessive travel between the piston and the other actuator component beyond the maximum possible travel between the strut and the container is permitted by displacement of the strut relative to said other component.

Abstract: A slack adjuster for a vehicle braking system includes first and second members having a normally reversible screw-thread connection therebetween. The first and second members are disposed between first and second pistons respectively of the braking system and excessive displacement of the pistons causes relative displacement between said first and second member to reduce the displacement of the pistons on the succeeding stroke. One of the first and second members may be a slit or split nut and a wedge member can be provided for urging the slit or split nut against the other of the first and second members to prevent relative rotation therebetween under a brake-applying thrust. The slit or split nut is resiliently biased against the other of the first and second members to prevent undesired relative rotation at the screw-thread connection. The slit nut can be formed as a spring-biased piston designed to prevent over-adjustment due to brake deflection.

Abstract: A combined hydraulically operated service and mechanically operated parking brake of the disk type. The components are arranged to provide an extremely compact assembly that may be fit into existing vehicles. The mechanical actuator includes a roller type cam mechanism with an externally actuated operating lever. The mechanism is constructed to provide a minimum number of seals and a lip type seal is embodied that will provide a ready indication on test if the seals of the hydraulic portion of the brake are defective. An improved automatic adjustor interconnects the mechanical actuator with the piston of the hydraulic brake to adjust for wear of the brake linings.

Abstract: An automatic adjuster comprises a mechanism of adjustable length operative between a hydraulic brake piston and either a cylinder or an opposed piston. A cam journalled in the cylinder or the opposed piston serves to apply the brake mechanically (hand brake) and act as a stop for the mechanism. The adjustable length mechanism comprises two members, one of which may be the first mentioned piston in interengagement with one another through a non-reversible screw-thread connection. A reversible screw-thread connection or a reversible face cam is provided for turning one member of the mechanism relatively to the other responsively to excessive piston travel to effect adjustment.