Abstract: A brake actuator device having a pneumatic service brake piston and a spring parking or emergency brake piston operation of either one of which effects displacement of a brake actuator rod which includes a screw-threaded spindle that operates in a non-rotatable nut member in order to adjust the length of the actuator rod. The nut member is provided with an external projection to which the vehicle brakes are mounted. A cogwheel is rotatably fixed to the actuator rod and is normally locked against rotation by a locking pin that engages the cogwheel teeth. The actuator rod is formed in two portions that are connected together through a clutch arrangement, the actuator rod portion having the threaded spindle being free to rotate during brake release to increase the actuator rod length and thereby take up the brake slack.

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

Abstract: A spring-loaded brake cylinder has a slideable braking piston one side of which is acted upon by a first spring in the braking direction and a second side acted upon by air under pressure in the release direction against the force of the spring. There is a releaseable mechanical coupling between the braking piston and a piston rod upon which is mounted a quick-acting piston. The quick-acting piston is actuated by air. The position of the braking piston controls a supply of air to and a discharge of air from the quick-acting piston so as to achieve pressurization and depressurization of the quick-acting piston.

Abstract: An improved emergency and service brake actuator for a wedge type brake is of the type which includes a tubular structure extending from the brake and housing an extended end of a stem of the wedge of the brake therein. An emergency brake actuation portion is mounted on the tubular structure and includes an emergency actuation rod extending into the tubular structure. The emergency brake actuation portion is capable of producing axial movement of the emergency actuation rod to cause an end thereof within an interior of the tubular structure to be selectively located at one of a first position toward the brake for emergency actuation of the brake and a second position remote from the brake. The improvement includes a service cylinder mounted on the end of the emergency actuation rod within the interior of the tubular structure and capable of being axially moved therein. A service piston is mounted on the extended end of the stem for sealed movement within the service cylinder.

Abstract: A door closer comprising at the end of one of two pivotally interconnected arms a closing device whose housing encloses a cylindrical piston driven by the arm through a rack-and-pinion system. On each side of this piston a return spring and a bag, filled with an incompressible but deformable viscous gum placed in a hollow piston biased elastically toward the cylindrical piston are placed on each side of the first-mentioned piston. The hollow piston has a diameter distinctly larger than the diameter of the first-mentioned piston, and the combined actions of this difference in diameters and of the viscosity of the gum ensure an effective braking of the return of the first-mentioned piston.

Abstract: A clutch or brake cylinder has an annular working space accommodating an annular piston which confronts a stack of interleaved friction plates adapted to couple the cylinder to a coaxial member rotatable relatively thereto, the piston being displaceable by fluid pressure toward the stack against the force of a Belleville spring. This piston occupies only part of the working space so as to leave an annular clearance in which an ancillary sealing ring is independently slidable. When fluid pressure is applied, part of that pressure pushes the sealing ring against the Belleville spring and lifts it off the piston which then can exert its full force upon the stack of friction plates. Extraction of the cylinder from a surrounding housing enables the piston and the sealing ring to be replaced by a larger piston, filling the entire cross-sectional area of the working space, if a greater coupling pressure is to be exerted.

Abstract: In the preferred and illustrated embodiment of a valve actuator, a vane type fail safe actuator is disclosed. The actuator comprises a housing enclosing a vane which is integral with a shaft extending through the housing to a rotary operable valve. Fail safe operation is provided by a spring return mechanism connected to the housing. Compressed air is utilized to operate the actuator and the spring return mechanism which assures complete valve closure when the air supply fails or is reduced below a predetermined minimum setting.

Abstract: A brake cylinder device combining a pneumatically-applied service brake and a spring-applied parking brake in a compact unit made possible by limiting the stroke of the parking brake piston to minimize the expansion of the spring and thus the amount of force relaxation, so that a relatively small spring may be used. The service brake piston carries a threaded shaft on which a nut is rotatably carried for locking engagement with the parking brake piston.

Abstract: In a brake actuator device having a fluid pressure actuated service brake and a spring-applied, fluid pressure released auxiliary brake that cooperates with the service brake via a friction clutch mechanism, there is provided a manual release mechanism for releasing the spring-applied brake in the absence of fluid pressure. The manual release mechanism operates to relieve the tension of the actuating spring by causing the piston through which the spring operates to engage a stop formed on the casing of the brake actuator device, so that the spring is caged at its opposite ends by the casing of the brake actuator device. Extension of a retracting screw to initiate the manual release operation is automatically retracted following engagement of the spring piston with its stop to reset the manual release mechanism in readiness for a subsequent operation.

Abstract: This invention relates to fluid pressure servo motors having two operatively independent fluid chambers, each chamber having a piston means therein movable in response to a fluid pressure differential so as to alter in use a two position device from one to the other of said two positions, each piston means having a lost motion means connection to allow the idle return of the piston in the event of cessation of the fluid pressure differential, wherein the two pistons are co-axial and move in opposite directions in response to the pressure differential and one piston is fixed to a stirrup formed as a wire loop which bridges the other piston to act in use against said device.

Abstract: A spring-loaded braking cylinder has a rapid release mechanism which disengageably connects the spring-loaded piston with the piston rod. A damping mechanism damps the relative movement between the piston and the piston rod which occurs upon release of the coupling between the spring-loaded piston and the piston rod. The piston rod is coupled to the piston by a transverse pin a portion of which projects into a transverse slot on the piston rod and another portion of which is movable within an L-shaped slot on the piston rod. An adaptor connected to the pin has a flange which acts as a piston within a closed chamber formed with the piston rod and filled with fluid. The spaces on both sides of the piston-like flange are interconnected by throttle passages.

Abstract: A spring-applied, air-released parking brake, having a manual release mechanism with an automatic reset feature. To release a spring-applied parking brake, in the absence of air, a torsion bolt having a cam member formed on it is manually rotated to a position aligning the cam with an elongated slot in the piston push rod of the parking brake cylinder. This allows the piston to be extended in a direction to extend the spring, thus relieving the spring force. Reapplication of air pressure moves the piston push rod out of the elongated slot to permit angular rotation of the bolt by its torsion spring, so as to prevent its entry in the elongated slot until the bolt is again rotated manually.

Abstract: The cylinder has an open-ended longitudinal bore. A removable plug closes one end of the bore. A power piston is slidably mounted in the bore. A pressure inlet port admits pressure fluid into the bore between the plug and the piston for shifting the piston in the bore. A rod is slidably and preferably sealingly mounted in the opposite end of the bore. The rod shifts in response to an external force and to the force exerted by the power piston. The power piston is easily removed from the bore by removing the plug from the cylinder.

Abstract: An improved spring guide incorporating a collapsible telescoping sleeve assembly is used in conjunction with a conventional fluid pressure operated brake of the type having a safety brake mechanism which employs a spring powered brake actuator for automatic activation of the safety brake in case of an emergency or a pneumatic failure.

Abstract: A spring brake actuator including an advantgeously formed housing having a longitudinally extending cavity therein for retaining a bolt useful in releasing spring induced brake application, and apparaus for selectively communicating fluid from one side of a spring piston of the actuator to the other side of that piston through the cavity.

Abstract: A valve actuator includes a hydraulic cylinder with a pair of pistons separately, slidably mounted therein for movement between a first end and a second end of the cylinder. An actuator rod is joined to a first of the pistons to extend through an opening in the first end of the cylinder to terminate exterior thereto and be capable of being joined to a valve stem. A high pressure gas accumulator is mounted on the cylinder to locate the second end thereof within the accumulator. The second end of the cylinder has an end closure with access therethrough to allow communication between the interior of the accumulator and a first side of the second piston of the pair. Normally, hydraulic oil is supplied to the cylinder to act on the first piston thereby causing both pistons to move axially against the high pressure gas of the accumulator which, in turn, axially moves the pistons when the hydraulic fluid is discharged.

Abstract: A fluid pressure operable servo positioner including a pair of operating piston units diametrally opposingly arranged relative to and abuttingly engageable with opposite sides of a mechanical operating member or lever for positioning the operating member in a preselected position determined by the degree of actuating pressure acting on the piston or pistons which are retractable by return springs, when relieved of actuating pressure acting thereon, completely out of contact with the operating member to an extent at which the operating member may be manually positioned, within a full range of positions, free of any resistance such as piston friction.

Abstract: A servomotor for power actuation of a mechanical or hydraulic control, for example brake master cylinders for motor vehicles, is disclosed. The servomotor includes a housing in which a power piston separates a low pressure chamber from a high pressure chamber. The power piston being movable from an idle position in response to a pressure difference between the chambers. The pressure difference being controlled by a valve associated with an inlet control member. An auxiliary power member is located in the high pressure chamber. The auxiliary power member has a pressure compartment connectible to an external pressure source. The auxiliary power member is adapted to move the power piston from its idle position irrespective of the establishment of the pressure difference, to permit the servomotor to be used in an automatic or emergency service brake system.

Abstract: A fluid actuator for 90.degree. rotating valves having a return spring coupled to an independent fluid actuated piston to assist in spring compression on the forward stroke.

Abstract: A powered tool control device having a pair of coaxial pistons, with the first piston effective to move the second piston after completing a predetermined amount of pretravel initiated by a prescribed operational condition of the powered tool and with resulting movement of the second piston controlled by fluid directional regulators responsive to different operational conditions of the powered tool.

Abstract: A vehicle braking means is disclosed in which an auxiliary chamber 2 comprises a locking mechanism whose function is to lock together a piston 5 and a piston rod 16. The locking mechanism comprises a spring-loaded guide 19 and locking elements 20 arranged to constantly contact the guide 19 and to engage the piston 5. To release the vehicle brakes, provision is made of a rod 21 or a pushrod 43 extending from the auxiliary chamber 2. As compared with the constructions known currently, the auxiliary chamber 2 is more readily operable and convenient in use.

Abstract: A master cylinder has a first piston and a second piston slidably disposed respectively in two piston chambers of different diameters, reduced diameter stems projecting from the opposing end portions of the pistons respectively, a flange formed around the outer periphery of each of the stems, and a split sleeve consisting of two or more co-operating elements and having stepped portions in the inner circumference thereof at the opposite ends respectively, the split sleeve being restrained in a cylindrical shape with the stepped portions engaging with respective flanges thereby connecting the two pistons with each other.

Abstract: A spring brake actuator has manual means for discontinuing and automatic means for restoring the spring braking function. A non-self-locking nut member is rotatable about the spindle and is releasably locked to the brake cylinder in that direction it rotates due to spring force.

Abstract: A position regulator is provided which is effective to control, via a control unit, a pressure medium circuit to operate at different working pressures. The regulator comprises two or more pressure transmitting elements which divide an internal space into a number of pressure chambers, the pressure transmitting elements being arranged for axial movement within the position regulator. The invention provides pressure transmitting elements defining the pressure chambers which comprise diaphragms or the like which are attached in mutually spaced relationship in the position regulator and which, when subjected to a force, permit axial displacement movements.

Abstract: A manual disconnecting device is provided for disengaging the brake push rod in a spring brake actuator having a movable piston holding the spring compressed by fluid pressure during normal operation. The device once manually disconnected is automatically reconnected upon a normal spring compression stroke of the piston. The disconnecting device provides a clutching device between the piston and the push rod engaging a nut threaded on the push rod with non-self-locking threads. In one embodiment the nut is journalled in the piston. In another embodiment there are clutch surfaces on both the piston and nut which are disengaged by a rotary motion from a special tool.

Abstract: A fluid brake actuating mechanism is described which includes a service brake chamber and a spring actuated auxiliary brake chamber. A device for centering the spring in the auxiliary brake chamber, not only under static conditions, but also under dynamic conditions by guiding the auxiliary piston plate during movement thereof is disclosed. The adaptation of the centering device for brake actuating mechanisms of different structures is described.

Abstract: A hydraulic disc brake actuator is disclosed. The actuator uses a first hydraulic motor for actuating a service brake, and a spring-applied, hydraulically released motor for emergency or handbrake applications. If the braking system malfunctions or is disengaged from its source of hydraulic pressure, the spring motor may be used to apply the brake by merely venting its associated hydraulic motor. The spring brake may be released by energizing a second hydraulic motor, or by using a mechanical restraction device to compress the spring motor. The spring-applied brake may be used as a parking brake or as an emergency brake.

Abstract: A brake cylinder device including a conventional release piston spring-biased toward a full-application or emergency application position and operable responsively to fluid pressure applied thereto in opposing relation to the spring force acting thereon, to a brake release position, a conventional service application piston, both pistons being subjectable concurrently to fluid pressure for operating the release piston to its release position and the service piston to a service brake application position in accordance with the degree of fluid pressure acting thereon, and a locking mechanism for automatically locking the release piston in its release position upon attainment of a full service application and thereafter during service braking operation at less than full service level and while the vehicle is in motion, and being operable for unlocking the release piston upon stopping of the vehicle and withdrawal of service braking fluid pressure.

Abstract: A disc brake comprising a caliper housing having axially aligned first and second cylinder bores; a first piston slidable within the first bore and bearing against one of the friction pads; and a second piston slidable within the second bore and having an internally threaded tubular opening into which a clearance adjuster is screwed. The threads of the adjuster are power transmission threads with a helix angle of about 15 degrees, and there is end-wise clearance between the threads sufficient to allow the first piston to move between its retracted and brakes-applied positions. At the end of the adjuster is a head having a conical clutch facing that engages a corresponding conical seat in the bottom of the first piston, so as to exert a powerful rotational clutch action. A spring urges the adjuster toward the bottom of the first piston, and causes the adjuster to unscrew and extent itself whenever there is any clearance between the clutch facing and seat.

Abstract: The present invention is related to a piston-cylinder mechanism for the pivoting or tilting of the platform of a vehicle mounted goods elevator between a raised resting position and a lowered working position, including at least one piston rod slidably movable relative to a piston in the mechanism and uniformly movable by means of a driver together with the piston between a bottom position wherein the platform is lowered and an intermediate position determined by a stop limiting the piston travel, said piston rod being movable relative to the piston between said intermediate position and a position of maximum extension out of the cylinder wherein the platform is swung up, wherein a spring, adapted to be supplied with spring force when the piston rod is moved towards its position of maximum extension out of the cylinder, urges the piston rod from said position in a direction towards the bottom position thereby to initiate at all times a lowering of the platform.

Abstract: A fluid reservoir device for use in conjunction with fluid-filled systems, such as helicopter blade dampers, comprises a cylindrical chamber wall closed across its bottom by a mounting shank having a fluid inlet opening formed therethrough. A first piston is slideably mounted within the cylindrical chamber wall and spring biased downwardly therein, and a second piston is slideably mounted in the first piston, and is spring biased downwardly therein, the combined work surfaces of the first and second pistons closing the cylindrical chamber wall wherein a chamber is defined having a volume which varies according to the positions of the first and second pistons. The chamber is filled by moving the first piston (and the second piston mounted therein) upwardly, and the first piston is spring biased downward to force fluid from the chamber to the fluid-filled system as required.

Abstract: A carburettor for an internal combustion engine includes a chamber into which fuel is introduced from a metering valve to produce a fuel/air mixture in the chamber. A main valve controls the rate of flow of fuel/air mixture from the chamber and a further valve upstream of the main valve is provided the opening of which controls the opening of the metering valve. The further valve opens so as to keep the pressure between the main and further valve constant with changes in flow rate through the chamber. Means are provided to provide an indication of the pressure of fuel/air mixture downstream of the main valve such that the metering valve can be further opened as a function of changes in said pressure downstream of the main valve.

Abstract: A spring brake actuator has a fluid actuated piston coupled to the brake applying piston rod through a manually disconnectable conveying mechanism which enables the piston rod to return alone and which thereafter returns automatically to a position for conveying the piston rod in response to the piston movement.

Abstract: A manual disconnecting device is provided for disengaging the brake push rod in a spring brake actuator having a movable piston holding the spring compressed by fluid pressure during normal operation. The device once manually disconnected is automatically reconnected upon a normal spring compression stroke of the piston. The disconnecting device provides a clutching device between the piston and the push rod engaging a nut threaded on the push rod with non-self-locking threads. In one embodiment the nut us journalled in the piston. In another embodiment there are clutch surfaces on both the piston and nut which are disengaged by a rotary motion from a special tool.

Abstract: An actuator for a spring brake used for parking and emergency has a spring operating on the brake push rod which will apply braking unless fluid pressure in the braking system applied to a piston overcomes spring pressure. To disable the spring brake the rod is retracted by a mechanism coupling the piston to the rod so that the brake is automatically restored into service when the piston is operated by the fluid pressure. The mechanism has a one-way clutch engaging a threaded push rod by means of a nut in non-self-locking engagement on the push rod threads.

Abstract: A hydraulic hand brake for a fluid pressure actuated brake on a railway vehicle has a cylinder and piston assembly extending coaxially from the brake cylinder. A threaded rod having a non-locking thread extends from the piston and has threaded thereon a traveling nut with a coupling surface on a side away from the brake piston engageable with a second coupling surface on a ring attached to the cylinder. A spring urges the nut in the direction to engage the coupling surfaces and a control piston engages the nut to disengage the coupling surfaces when the control piston is subjected to a hydraulic pressure. Subjecting the piston of the cylinder and piston assembly to a hydraulic pressure will cause the threaded rod to engage the brake piston and to move the brake piston in the braking direction.

Abstract: A position regulator is provided which is effective to control, via a control unit, a pressure medium circuit to operate a different working pressures. The regulator comprises two or more pistons dividing a common cylinder into a number of pressure chambers, the pistons being arranged for movement relative to one another. The invention provides stop means for each separate piston, each stop means being individually adjustable to produce different lengths of stroke for the respective pistons whereby the output piston rod from the cylinder is caused to adopt a number of axially determined limit positions depending upon the control pressure applied to respective pressure chambers.

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

Abstract: A device in which a contact base of a contact breaker is rotated about a cam shaft for effecting ignition timing adjustments for an internal combustion engine. The device comprises a negative pressure chamber defined between a first diaphragm connected to the contact base and a second diaphragm disposed in spaced juxtaposed relation with and having a larger pressure receiving area than the first diaphragm, the second diaphragm being provided with a spring which precludes diaplacement of the diaphragm till the force exerted on the diaphragm reaches a predetermined value.

Abstract: The brake, including a brake housing, is characterized by a housing having an inwardly extending flange forming a pressure chamber with an annular piston slidably positioned in the brake housing, and the annular piston and a secondary piston are operatively associated with opposed sides of the inwardly extending flange to form pressure chambers therewith for individual actions in the brake. Spring means operatively engage the secondary piston for moving the same into operative pressure braking position for fail safe braking operation. Air pressure is supplied to the two pressure chambers or cylinders for controlling brake release and braking action.

Abstract: An actuating force generating device has a multi-stage cylinder body consisting of a plurality of cylinders having different diameters and arranged in series; a plurality of pistons slidably fitted in the cylinders, respectively; fluid ports each provided in the cylinders to discharge or introduce fluid from or into the cylinders; a container provided in the rear of the multi-stage cylinder body; a piston rod forming an actuating end projecting from the multi-stage cylinder body, said rod extending through a rod guide and being affixed to the forward piston; and a resilient member adapted to urge the rearmost piston forwardly.

Abstract: A vehicle wheel spring brake actuator has a service braking piston and cylinder assembly and an auxiliary parking or emergency braking piston and cylinder assembly, the emergency braking piston being spring biassed towards a brake-applying position and normally held off by an opposing fluid pressure, upon release of which the spring force is transferred through the emergency braking piston and a force transferring member to the service braking piston to apply the brake. A quick release device is movable through a small distance to permit relative movement between the force transferring member to release the applied brake, the release device and the force transferring member extending through the emergency braking piston freely and with clearance.

Abstract: A spring brake unit for use in a vehicle braking system comprises a housing, a piston movable therein and connected to a brake or brake linkage, a spring interposed between the piston and a detachable end wall on the housing and urging the piston in a direction to apply the brakes fluid under pressure being introduced to the housing in a controlled manner to hold the piston in brake-off position, and the housing and/or detachable end wall being formed to define one or more drainage channels opening into a gaiter which bridges the joint between them and which includes a drain outlet.

Abstract: There is disclosed apparatus for preventing explosive separation of a heavy spring loaded first portion of a parking brake chamber from a second portion thereof. A clamping band, typically secured by a fastener assembly, is provided at the interface between the two portions of the chamber to maintain them in operative engagement. The apparatus disclosed insures continued engagement upon accidental or inadvertent release of the clamping band under spring loading.