Abstract: A reservoir of synthetic plastics material for a master cylinder is constructed from a base and a lid which are permanently connected together at their mating faces, for example by welding, along a join line which lies in a single plane. A partition is upstanding from the base and a passage defined by a wall and including a portion of the lid provides limited communication between chambers on opposite sides of the partition. At least one end of the passage lies outside at least one edge of the lid and the join line passes through the partition.

Abstract: In an internal shoe-drum brake a thrust transmitting member is interposed between a shoe-end and an abutment for that shoe-end. The thrust transmitting member has a planar face engaging with the abutment and an arcuate face which is received in a complementary recess of arcuate outline in the shoe-end.

Abstract: A control valve assembly for vehicle dual hydraulic braking systems is operated by a lever mechanism. The lever mechanism comprises first and second levers which are pivotally connected to each other by a first pivot. One lever acts on a valve mechanism for controlling pressurization of a distributor chamber, and the other lever is pivotally connected to a housing through a second pivot. Each lever acts on a respective one of a pair of brake-applying valves for controlling the supply of pressure fluid in the chamber to an outlet in the housing for connection to a wheel brake.

Abstract: In a pressure modulator for an anti-skid braking system a spring acts through a modulator piston to bias a piston assembly into a position in which an inlet for connection to a pressure source is connected to an outlet for connection to a wheel brake. Normally the spring force is augmented by pressure supplied to the modulator piston through an anti-skid mechanism which cuts off the pressure supply if deceleration of a wheel exceeds a predetermined value, whereby the piston assembly moves into a position in which the outlet is cut-off from the inlet.

Abstract: In a rotor for vehicle brakes, for example, discs for disc brakes and drums for shoe-drum brakes, the braking member is carried from one side of a driving component for connection to a wheel or shaft. The outer face of the member remote from the driving component comprises a braking surface which can be engaged by at least one friction member. The braking member comprises an annulus, and the driving component a cast mounting which is formed with a discontinuous abutment face with which the braking member is in direct intimate contact over a substantial area. Clamping members additional to and separate from the annulus and the mounting are provided for clamping the annulus against the abutment face to maintain the intimate contact between them.

Abstract: In a fluid-pressure operated anti-skid braking system operation of a brake-applying relay valve is controlled by control pressure in an application chamber. A memory chamber is connected to the application chamber through a one-way valve and an orifice permits pressure in the memory chamber to decay into the application chamber when the pressure in the application chamber reduces. Re-application of the brakes following a skid is controlled by closure of a latch valve which permits only a restricted flow of control pressure into the application chamber. This is sufficient to re-apply the brakes rapidly in a first stage until the pressure in the application chamber becomes equal to that of the decayed pressure in the memory chamber, whereafter brake re-application continues at a slower rate since the restricted flow of control pressure has also to increase the pressure in the memory chamber.

Abstract: In an hydraulic system in which an hydraulic accumulator is charged with hydraulic fluid under pressure by means of an hydraulic pump which draws hydraulic fluid from a tank, and an unloader valve disposed in a supply line between the pump and the accumulator is operative to prevent the accumulator from being overcharged and to allow the pump to re-charge the accumulator should the pressure stored therein fall below a desired minimum value, the unloader valve incorporates a control valve, and a pressure responsive slave which is operated by fluid pressure under the control of the control valve.

Abstract: In a reservoir assembly for a tandem master cylinder of a hydraulic braking system the container is separated into compartments by at least one baffle passages being provided for permitting limited communication between the compartments past the baffle. The arrangement is such that when the container is installed in a vehicle and the brakes are applied, the tendency of fluid to transfer from one compartment to another is resisted. The arrangement also ensures that even under the worst conditions of deceleration and altitude of the vehicle there will be a sufficient volume of fluid in the compartments to cover outlets to the master cylinder and thus sustain subsequent brake application.

Abstract: In a reservoir comprising a container for liquid at least one portion of the top wall of the container is depressed to form a window, the depressed portion and at least a part of the surrounding area being transparent or translucent so that the reservoir can be filled with a liquid until the liquid is in visible contact on the under surface of the window with the surrounding part untouched.

Abstract: The frequency of a pulse signal is measured by counting the number of complete pulse cycles and measuring the fractional value of any incomplete pulse cycle occuring during a fixed sampling period, and summing said number of complete pulse cycles and said fractional value of any incomplete pulse cycle so as to obtain a total proportional to said frequency. The length of the incomplete pulse cycle is measured using a clock pulse signal having a base frequency which is multiplied by an integral fractor corresponding to the number of complete pulse cycles occurring during said sampling period, said integral factor being increased by one between successive pulse cycles and the length of each and every pulse cycle being measured in the corresponding clock pulse units.

Abstract: In a fluid pressure-operated anti-skid braking system for vehicles, operating fluid from a supply is supplied to the wheel brake through a fluid-flow control valve interposed between the supply and the brake. A deceleration responsive device responsive to a skid signal is incorporated for operating the control valve to relieve the brake pressure of the fluid supplied to the brake when the deceleration of the wheel is excessive and exceeds a pre-determined value. A memory for storing a memory pressure dependant on the brake pressure at a skid is incorporated, and the memory pressure operates the control valve directly during a first stage of brake re-application, and provides a changeover point between first and second stages of brake re-application. The second stage comprises continued re-application but at a reduced rate of pressure increase.

Abstract: In a vehicle disc brake of the single sided sliding reaction caliper type the drag on the friction pad assemblies is taken by a drag-taking member. The caliper is slidably mounted for movement relative to the disc on a guide in the form of a single pin which is located on the same side of the disc as that on which an actuator for the brake is located.

Abstract: An anti-skid brake control system which is adapted to control the brake of a wheel comprising a brake release switch that produces a control signal to release the brake on detection of the onset of skidding of the wheel, a sensor for producing an electrical signal proportional to the angular acceleration of the wheel, a charging circuit which is responsive to the acceleration signal and produces a corresponding output signal so that the amplitude-time curves of the two signals cross-over one another after the acceleration peak resulting from release of the brake, and a brake re-applying switch which compares the acceleration signal and the output signal from the charging circuit and produces a control signal to re-apply the brake after the cross-over point.

Abstract: In a spot-type disc brake the pads are insertable in a substantially peripheral direction through openings in an end of the brake. In service the openings are blocked by a closure member which has to block the two openings two limbs each extending through the openings to engage the pads. The member is pivotal about an axis parallel to the rotational axis of the brake's disc and disposed outside the disc's periphery. The brake's caliper is made in two halves bolted together and has blind journals receiving trunnions integral with the member. The drag force tends to act along the limbs so that the drag force is taken substantially entirely by the trunnions.

Abstract: A sliding caliper disc brake comprising a torque member which is adapted to be fixedly mounted adjacent a brake disc and which has portions lying on both sides of the brake disc which are connected by bridging portions positioned radially outwardly of the periphery of the disc. Directly and indirectly operated friction pad assemblies are located on opposite sides of the disc and each include a friction pad carried by a respective pad backing plate. A caliper member is mounted on the torque member. The caliper member is guided for sliding movement relative to the torque member in a direction perpendicular to the disc, the caliper member and both the friction pad assemblies being supported by the torque member so that drag forces experienced by the pads during use of the brake are transmitted directly to the torque member.

Abstract: A vehicle braking system employs a fluid pressure operated device for engaging the brakes. Flow of liquid under pressure to this device is controlled by a solenoid inlet valve and escape of fluid is controlled by a solenoid outlet valve both of which are normally closed. A demand signal and a feedback signal representing the degree to which brake operation has been achieved are fed to a comparator circuit and the valves are energized in accordance with the sign of the error signal. Operation of the respective means for controlling the operation of the respective valves is obtained by a pulse train generator, and a pair of pulse width modulating means, connected to the respective valves for modifying the mark-space ratio of the pulse train.

Abstract: In a disc brake including pad assemblies for engagement with opposite faces of a rotatable disc and a clamp assembly extending over the peripheral edge of the disc, the clamp assembly comprises pressure plates interconnected by spaced parallel limbs passing through superimposed openings in the plates and interconnected at one pair of adjacent ends by a bridge piece which acts on one of the pressure plates.

Abstract: In a disc brake of the kind in which the clamping member straddling the disc consists of pressure plates located on opposite sides of the disc and interconnected at their outermost ends by draw-bars, each draw-bar is provided at one end with a threaded portion and the threaded portions are passed through spaced clearance bores in the pressure plate to which those ends of the draw-bars are to be connected. The pressure plate is clamped between pairs of axially spaced nuts screwed onto the threaded portions.

Abstract: An automatic slack adjuster for a vehicle brake linkage comprising a housing constituting a lever in the linkage, and the lever is angularly movable about the axis of a shaft to impart to the shaft a brake-applying rotary movement which it transmits to it through a meshing worm and worm wheel assembly. Automatic worm driving means are incorporated for rotating the worm for adjustment of slack in the linkage in response to relative movement between the lever and a relatively stationary part, and the worm driving means incorporates a connection having a degree of lost-motion equivalent to a desired braking clearance, and a spring-loaded two-part clutch disposed between the worm and a slidable pawl connected to the stationary part.