Abstract: In an hydraulic power booster a boost piston working in a bore in a housing is of stepped outline having at least three axially spaced portions of at least two different diameters. The two end portions carry seals having slidable sealing engagements with complementary portions of the bore, and a stationary seal is fixed in the housing. An intermediate portion of the piston disposed between the end portions and of smallest diameter has a slidable engagement in the stationary seal.

Abstract: An anti-skid braking system incorporates a modulator assembly through which fluid from a source is supplied to a brake. The modulator assembly comprises a de-boost piston working in a bore in a housing, an expander chamber connected to the brake and defined in the bore between one end of the piston and a first valve, and a second valve for controlling the application to the piston of support fluid to determine the relative position of the piston in the bore, the second valve being manipulated in response to a skid signal. The first valve is normally biassed in to a fully open position, and the operation of the first valve is controlled independently of the piston. An inhibit device is incorporated to ensure that at the termination of a skid signal first valve is maintained in a closed position at least until the piston has returned to an advanced position in which the effective volume of the expander chamber is at a minimum value.

Abstract: An apportioning valve for controlling the pressure applied to the rear brakes of a vehicle comprises an inlet to receive actuating fluid and an outlet for connection to the rear brakes. The inlet and outlet are normally connected via an inlet chamber, and an auxiliary chamber is connected to the inlet chamber via a throttle and to a vent valve seat. A pendulum is biased against the valve seat during deceleration and thus closes the valve seat and allows pressure to build up in auxiliary chamber. When pressure in the auxiliary chamber is sufficiently high control pistons move to isolate the inlet from the outlet.

Abstract: A booster for a vehicle braking system has an input piston, a boost piston and an output piston working a bore, the boost piston being advanced in the bore in response to pressure fluid from a source pressurizing a boost chamber under control of a valve.The operation of the valve is dependent on the pressure in the system, and the valve has a valve mechanism working in a bore in the boost piston of which one part has a pressure-responsive face, the valve being operative, on initial movement of the input piston to cause pressurization of the braking system to the threshold level, and application of pressure fluid to the pressure-responsive face to move the part relative to the input piston to place the boost chamber in communication with the pressure source. Threshold pressurization of the braking system may be achieved by pressurization of the boost chamber, or an auxiliary chamber forward of the boost piston to a predetermined level.

Abstract: A helmet 1 adapted for use by hay fever sufferers is shaped to fit over the head and face of the wearer and has filtered air supplied to its interior by way of an air supply duct 5 from portable filter means remote from the helmet and adapted to be carried by the wearer. The filter means removes pollen, dust and such airborne matter from the air supplied to the helmet. The filter means comprises disposable filters 9, a battery operated electric motor 8 and a fan 7 driven by the motor which draws air from the atmosphere through the filters and supplies it to the air supply duct 5. The battery 13 energizing the motor is in a separate box 14 from a box 6 containing the filters, motor and fan. Both boxes are adapted to be attached to a belt to be worn by the helmet wearer. There may alternatively be just one pack. The helmet has supports 4 which seat on the wearer's shoulders.

Abstract: A sectional hydraulic valve has clamped together an inlet section, an outlet section and at least one working section which can be integral with the inlet and/or outlet sections. Fluid supply and return passages are formed in the sections and are in register at each junction where there are formed contiguous planar sealing surfaces. A depressed area is provided in one of the surfaces surrounding the contiguous planar sealing surfaces of the supply and return passages and a groove containing a sealing ring is formed in one of surfaces around the depressed area. A drain passage leading to a low pressure region opens into the depressed area and should there be leakage between the sealing surfaces of the supply and return passages, particularly as a result of the presence of high pressure in said passages, the leaked fluid merely passes into the depressed area and flows through the drain passage to the low pressure region without subjecting the sealing ring to pressure and possible leakage there past.

Abstract: A mechanical brake actuator has rotatable and non-rotatable cam components provided with confronting helical grooves between which ball bearings are arranged to form a helical thrust bearing. A push rod, connecting rod or the like acts generally tangentially on a lever arm on the rotatable cam component for turning the latter. The lateral reaction arising from the lateral force due to the push rod is transferred from the rotatable cam component to the non-rotatable cam component by the helical thrust bearing, thereby avoiding the need to provide a separate journal bearing for the rotatable cam component. The rotatable cam component acts on a tappet member via an axial thrust bearing and an automatic adjuster mechanism.

Abstract: Apparatus is disclosed for bonding a plurality of cores of a multi-core ribbon electric cable in side-by-side relationship by heating the insulation of the cores to bond together the insulation of adjacent cores. Instead of continuously bonding the cores together along their entire length, the apparatus is designed to interrupt the bonding at predetermined intervals so that when the cable is cut at a sectional interval it is not necessary to separate the insulation of one core from the next.

Abstract: An anti-skid braking for a vehicle comprises a wheel having an hydraulic brake applicable by supplying thereto fluid under pressure from a master cylinder, a sensor to sense the presence of skid conditions at the wheel during braking and thereupon to produce a skid signal, a dump valve operative to cause fluid to be displaced from the brake in response to a skid signal so as to relieve the brake pressure, and a flow-control regulator valve arranged to regulate flow of fluid to the brake so as to re-apply the brake pressure at a controlled rate. The flow-control valve comprises a first restriction of predetermined size connected in series with a second restrictor defined between two relatively movable members and located upstream of the first restriction. The first restriction is defined at least in part by the member of which that member is biassed by a valve spring against the action of the pressure difference across the first restriction.

Abstract: A wormwheel (1) has teeth (2) over at least a portion of its periphery. The teeth (2) are shaped such that the pitch diameter (5) is greater at one face (3) of the wormwheel than the other and does not increase along the path of the tooth from said one face (3) to the other face (4). Because of this tooth shaping the wormwheel may be cast and is thus suitable for mass production. Wormwheels of this type are particularly, but not exclusively, suitable for use in valve actuators. In order to facilitate the casting process the wormwheel is formed with only one integral bearing (10) and has an internally splined opening (8) in which can be received a bearing sleeve (18) which may also be adapted to receive the valve stem within its own axial opening (21). A variety of bearing sleeves suitable for use with different valve stems may be provided for cooperation with the same wormwheel thereby eliminating the need for special adaptors and reducing the number of parts required to construct a range of valve actuators.

Abstract: A heater for heating a liquid including a housing defining a closed elongate heating chamber therein with a cylindrical chamber surface, a rotor body rotatably journalled in the heating chamber with a cylindrical peripheral surface thereon concentrically of the chamber surface so as to define an annular space between the chamber surface and the peripheral surface on the rotor body, drive means for effecting relative rotation between the rotor body and the housing, and pump means for circulating the liquid through the annular space so that the rotation of the rotor body heats the liquid passing through the annular space.

Abstract: The present invention relates to a fuel saving device adaptable to all types of carburetors, petrol engines and domestic or industrial burners, constituted by a solenoid generating a magnetic field which has an influence on the air-fuel mixture.Said solenoid has a red copper coil, has its axis oriented in parallel to the axis of the engine, and, periodically, in a first pre-determined direction, during the moon phase which goes from the full moon to the new moon, and in a second, opposite, direction, during the moon phase going from the new moon to the full moon.The invention finds an application in motor engine of low consumption.

Abstract: A vehicle brake control device especially suitable for load carrying vehicles comprises a device for sensing front and rear brake pressure and vehicle deceleration, and a control device for maintaining the relationshipAP.sub.1 -BP.sub.2 +C=Dfwhere P.sub.1 is the front brake pressure, P.sub.2 is the rear brake pressure, f is the sensed deceleration, and A,B,C and D are constants with A greater than B.

Abstract: The present invention provides a hydrostatic bearing type coupling for a vibrating machine. The coupling is interposed between a vibration table upon which a test specimen or the like is mounted and a vibrator in such a way that even when the vibration table is caused to vibrate three-dimensionally, there are free movements in the two directions.

Abstract: A brake actuator comprises a piston working in a cylinder with a seal carried by the piston for engagement with the outermost wall of the cylinder and a seal housed in the innermost wall of the cylinder for engagement with the piston. Each seal is of triangular outline and is received in a seal-receiving groove which has first and second relatively inclined end walls with which faces on the seal are in full facial engagement, and a sealing region for engagement with the wall of the cylinder or the piston is defined by and between the third remaining face and the adjacent face of the seal. A space is provided between the second end wall and the third face to accommodate any deformation of the material of the seal which is otherwise confined between the piston and the cylinder.

Abstract: An anti-skid hydraulic braking system for a vehicle includes a modulator which in response to a skid signal at a skid point is operative to relieve the brake-applying pressure at a braked wheel by displacing fluid from the brake. The modulator includes a brake-application restrictor which is operative to control the rate at which the brake-applying pressure from a source can be re-applied to the brake at the cessation of the skid signal, and a valve assembly is incorporated to by-pass the re-application restrictor. The valve assembly comprising first and second valve members which are relatively movable between a spaced inoperative position in which unrestricted communication is provided between the source and the brake and an operative position in which the valve members are urged into engagement to render the restrictor effective.

Abstract: A tread brake for braking a wheel (2) of a railway vehicle which is sprung relative to a frame (4) of the vehicle, comprises an actuator (5) suspended from the frame (4) by a swing arm (6), and a rigid link arm (7) fixed to the actuator (5) and connected through a pivot (8) parallel to the wheel axis to a bracket (9) fixedly mounted to a bearing in which the wheel axle is journalled. The link arm (7) adjusts the position of the actuator (5) in response to any movement of the wheel (2) relative to the frame (4) so that the braking element (11) is always applied substantially radially to the wheel, which allows the element to take the form of an elongate rod of friction material. A new handbrake structure is also described.

Abstract: A master cylinder for a hydraulic brake system includes a piston which divides a primary bore into a primary chamber and a secondary chamber. The piston rod sealingly slides in a secondary bore of smaller cross-sectional area than the primary bore. An expander piston sealingly slides in a bore and defines a primary expander chamber and a secondary expander chamber. In use, initial movement of the piston causes fluid to be displaced from the primary chamber to the brake circuit at a rate corresponding to the area of the primary bore. When the pressure in primary chamber becomes sufficiently large the expander piston is moved to the right against the bias of a spring to allow fluid to flow out of primary chamber into primary expander chamber via a passage. An equal volume of fluid is displaced from secondary expander chamber into secondary chamber via a passage.

Abstract: A load conscious control valve arrangement for modifying the pressure applied to the rear hydraulic brake of a motor cycle comprises a control valve rigidly mounted by a bracket on the frame of the motor cycle. The stem of the control valve is connected by a tension spring to an adjustable spring support of a combined spring/damper suspension strut. Deflection of the rear suspension as a result of increased loading causes an increased tension to be applied by the spring and thereby increases rear brake pressure. To compensate against the decrease in tension which would otherwise be applied to the valve stem when the adjustable stop is adjusted but there is no increase in the load on the motor cycle, an eccentric formed on the adjustable stop so that rotation of the stop may be provided to adjust the suspension strut causes a shift in the radial direction of the suspension strut of the point Z at which the spring is connected to the spring support.

Abstract: The present invention provides a friction pad assembly comprising a backing plate and a pad of friction material secured thereto, the backing plate having at least one hole offset from the central axis of the assembly, through which a pad support pin passes to engage a wire spring supported on the backing plate and having two generally oppositely directed arms. The arms engage either the pad support pins and/or part of the brake and produce an asymmetric loading of the pad assembly, the spring biassing the friction pad assembly against an abutment face of the brake to thus reduce the possibility of the pad assembly hitting the abutment face to produce disturbing `klonking`.