Abstract: In a multi-disc brake comprising a torque tube and a piston housing having a plurality of hydraulically operated and circumferentially spaced piston cylinders a thermal isolation element is arranged to restrict heat generated by the friction discs from flowing from the torque tube to the piston housing.

Abstract: Apparatus is provided for sewing the crotch portion of a pair of aligned blanks of limp fabric and stacking the sewn blanks which comprises robots (10 and 20) located one on each side of an operator. Each of the robots (10 and 20) is capable of gripping and removing a limp fabric blank from an associated stack of blanks and transporting the blanks to an operator. The robots (10 and 20) have arms (26) capable of axial movement and movement in a vertical plane and additionally capable of rotating about their axes through an angle of 180.degree.. At least one of the robots (10,20) is capable of rotation about a vertical axis, effecting horizontal movement of the arm (26). The apparatus also comprises a sewing head (30) for sewing the crotch portion of the pair of aligned blanks, and a blank support/transfer carriage (41) adjacent the sewing head mounted for horizontal movement in a direction substantially parallel with the direction of sewing.

Abstract: A striking implement comprises a handle portion and a striking portion, in which the striking implement is discontinuous in that it comprises two parts one part including the striking portion and the other part including the handle portion or a part thereof, the said two parts having complementary hollow formations which are assembled to overlap axially with a vibration-damping material interposed between and bonded to said formations, whereby the two parts are inseparably connected together but the vibration-damping material mechanically isolates one from the other, i.e. there is no direct contact between the two parts.

Abstract: An elastomeric mounting comprises a body of elastomeric material having end regions the surfaces which are bonded to respective confronting surfaces of a pair of rigid end members for compression therebetween. A first of the rigid end members (32) extends radially outwardly from a longitudinal compression axis (19) of the mounting to lie beyond the bonded interface (35). The first end member has outwards of the bonded interface an abutment face (34) which is contacted by the elastomeric body when subject to compression loading, and a discontinuity is defined by the first rigid end member whereby the interface and abutment face depart from a wholly co-planar form.

Abstract: A multi-disc brake suitable for an aircraft has a stack of rotor and stator discs in which the discs of a set at one end of the stack each have a greater allowance for wear than the discs of a set at the other end of the stack whereby the group of discs are removed together from one end of the stack as a fully worn group at a brake servicing operation. An unworn group of discs is added to the other end of the stack.

Abstract: An aircraft disc stack (1) comprises a plurality of interleaved stator and rotor discs (3,4) keyed respectively to a torque tube (5) and a wheel hub (not shown). The stack (1) further comprises bi-functional friction/load transmitting discs in the form of end stator discs (10,13). These discs (10,13) are subject to uneven loading because the non-friction surfaces (12,15) are in use compressed on areas less than the load bearing areas of the opposing friction faces (11,14). This can lead to premature disc failure and in the past load spreader plates have been used to distribute loading over these areas to minimize the risk of failure. In this invention portions of the load bearing areas of non-friction surfaces (12,15) are toughened ie: material underlying these surfaces is toughened, to increase their resistance to deformation, fracture and/or wear thereby removing the need for additional load spreader plates which were hitherto required.

Abstract: Method of fabricating a multi-ply carbon fibre fabric, preform or composite material from a layer of unidirectionally aligned carbon fibres of ultra-high modulus and a layer of low modulus carbon fibre comprising the steps of: arranging in superimposed relationship the layer of unidirectionally aligned carbon fibres of ultra-high modulus and the layer of low modulus carbon fibres so that at least a substantial number of the fibres of low modulus are disposed transversely of the fibres of the ultra-high modulus fibre layer, and connecting the two layers by interlacing fibres of the layer of low modulus fibres with those of the layer of ultra-high modulus fibres by needle-punching using felting needles orientated and configured so that their barbs snag only the low modulus fibres during passage through the layers.

Abstract: Valve system for a vehicle gas suspension system having a central chamber (41) to which pressurized gas is admitted via valve 50 or from which pressurized gas is exhausted via valve 51. Interposed in gas communication paths between the central chamber and each gas suspension unit (46-49) is a respective on-off valve unit (42-45). The valve system includes a regenerative drier (56) and a cushion valve (70) for protecting a compressor from overload during start-up.

Abstract: A vehicle suspension system incorporating suspension units (46-48) associated with respective vehicle wheels and selectively controllable to vary the ride height of the vehicle. Vehicle speed sensors and height sensors are responsive to departure of the ride height from a predetermined height datum which is a function of the vehicle speed and to provide a signal related thereto to control movement of at least one suspension unit thereby to tend to move at least a part of the vehicle to said predetermined height datum. Timer means are provided so that the movement of a suspension unit in response to a signal from a height sensor is inhibited until a signal of at least a predetermined magnitude has persisted for at least a prescribed part of a prescribed period of time.

Abstract: Apparatus is provided for sewing the crotch portion of a pair of aligned blanks of limp fabric and stacking the sewn blanks which comprises robots (10 and 20) located one on each side of an operator. Each of the robots (10 and 20) is capable of gripping and removing a limp fabric blank from an associated stack of blanks and transporting the blanks to an operator. The robots (10 and 20) have arms (26) capable of axial movement and movement in a vertical plane and additionally capable of rotating about their axes through an angle of 180.degree.. At least one of the robots (10, 20) is capable of rotation about a vertical axis, effecting horizontal movement of the arm (26). The apparatus also comprises a sewing head (30) for sewing the crotch portion of the pair of aligned blanks, and a blank support/transfer carriage (41) adjacent the sewing head mounted for horizontal movement in a direction substantially parallel with the direction of sewing.

Abstract: A floatable twin carcass hose has a main carcass surrounded by a secondary carcass adapted to expand radially if pressurized fluid leaks through the main carcass to between the two carcasses. There is buoyancy material around the secondary carcass, an outermost cover layer, and inextensible hoop reinforcement between the secondary carcass and outer cover at one or more localized positions along the length of the hose thereby locally to inhibit expansion of the cover if fluid leaks to between the carcasses.

Abstract: In a golf ball, non-circular isodiametrical dimples provide increased efficiency of coverage of the surface of a golf ball (in comparison with the conventional circular dimples). Additionally, the aerodynamic properties of the ball are improved.The dimples have the shape of a regular isodiametrical figure with an odd number of curved sides and arcuate apices. The number of sides of the isodiametrical figure conveniently is from three to nine.

Abstract: A method for the manufacture of a light-weight panel, e.g. for aircraft, comprising preparing a panel preform having a pair of surface members or skins separated and supported by an internal core in which spaces or interconnected pores provide vents to an edge of the panel, the wall surface members and the core comprising fibrous material, which may be carbon fiber, and using a pyrolysis process such as CVD to form a pyrolytic matrix around the fibers within the fibrous material, there being a flow of gas through the vents during the pyrolysis process.

Abstract: A multi-disc brake suitable for an aircraft has a stack of rotor and stator discs in which the discs of a set at one end of the stack each have a greater allowance for wear than the discs of a set at the other end of the stack whereby the group of discs are removed together from one end of the stack as a fully worn group at a brake servicing operation. An unworn group of discs is added to the other end of the stack.

Abstract: A laminated friction disc and method of construction in which a layer (11) of carbon composite material which provides a wear surface is secured against a second layer (12) of material with said wear surface facing away from said second layer of material, holes (16) being formed in each of the layers either before or after the layers are arranged against one another with the holes in the layer of carbon composite material extending through said wear surface and aligned with the holes in the second layer, fastening means (15), such as rivets, being positioned to extend through aligned pairs of holes and arranged to secure the layers against one another with each of the fastening means lying wholly below and spaced from at least the wear surface of the layer of carbon composite material.

Abstract: A heavy duty elastomeric bearing typically of annular shape comprises a pair of rigid end members spaced apart and interconnected by an element of elastomeric material having embedded therein a plurality of substantially rigid reinforcing interleaves each arranged to lie in respective planes generally parallel with confronting surfaces of the rigid members. One or more of the reinforcing interleaves lying substantially mid-way between the confronting surfaces of the end members has a greater thickness than one or more of the interleaves which lies closest to at least one of the end members. The confronting surfaces, elastomeric layers and reinforcing interleaves may each be of annular part-spherical shape.

Abstract: A novel games racket frame, particularly a squash racket frame is asymmetric in that the cross-section of the head portion measured perpendicular to the plane in which the strings will lie varies. Preferably the frame is strung in a "double fan" pattern i.e. the longitudinal strings diverge from the head portion adjacent the shaft portion and the cross-strings diverge from one side to the other.