Abstract: A sun visor is disclosed having a frame covered by trim material 9 and a mirror 2 slidingly supported by a cassette assembly 20 which is attached to the frame. The cassette assembly comprises a cover member 8 and a base member 7 snapfitted together by means of integrally formed latching means 14, 13. The mirror 2 is moveable from a first position where it is viewable through respective apertures 4, 4A in the trim material 9 and the cover member 8 to a second position where it is hidden from view.

Abstract: A threaded fastener is made by a method which involves forming a portion having an external thread form and a shank portion. The shank portion has at least one substantially circumferential groove the depth of which is such that the effective stress area thereby produced is less than the minimum effective stress area of the external thread form and is also such that yield of the threaded fastener occurs in use in the region of the or each groove at a predetermined load. The depth of the or each groove may be such that the diameter of the shank portion at the base of the or each groove is in accordance with the relationship: ##EQU1## where D is the diameter at the base of the or each groove (m).delta. is the tensile strength of the wire (N/m.sup.

Abstract: It has been proposed to employ a constant mesh gearbox of the kind having pairs of gears on parallel shafts in constant mesh with each other, together with a clutch, in an automatic vehicle transmission. A microprocessor controls actuators for the clutch and throttle and hydraulic actuators for moving the selector rod of the gearbox, in order to give automatic operation of the gearbox.In accordance with the invention, a constant mesh gearbox of the kind referred is provided with actuating means for moving the selector shaft and, in at least one direction of travel of the selector rod, the actuating means acts via resilient means which is arranged to store the energy of the actuating means when the actuating means is operated but the selector rod is not free to move, the rod being moved by the energized resilient means when the selector rod becomes free.

Abstract: A heat exchanger is provided in which two header tanks (11,12) are structurally connected together by two spaced apart casing members (15,16) therebeing a number of fluid conduits (13) to provide a fluid transfer connection therebetween. Each of the header tanks (11,12) includes a plate member (18) a side wall member (19) which defines in combination with the plate member (18) a fluid manifold each end of which is closed by a respective end cap (20A,20B,21A,21B). Each of the end caps (20A, 20B,21A,21B) includes means (25) used during assembly as an assembly aid. A further feature of the invention is the use of extruded material for several of the structural components.

Abstract: A power assisted steering system which utilizes a brushless electric motor having a rotor and a wound stator. The rotor is directly connected to the steering shaft 12 rotated by a driver of the vehicle, and is formed by a number of permanent magnets secured in respective recesses on the steering shaft. The controller 17 associated with the steering system is arranged to switch off the motor 15 above a pre-determined vehicle speed.

Abstract: An internal combustion engine inlet manifold is disclosed which comprises of a housing defining a plenum, at least one inlet tract and at least one rotary valve member supported by the housing. The or each inlet tract has first and second lengths one of which extends away from the plenum for connection to an engine to which the inlet manifold is to be connected. The or each valve member is arranged to be rotatable from a first position in which the first and second lengths are connected in series between the plenum and the engine via the or each valve member and a second position in which connection is made between the plenum and the engine solely by means of the first length of the or each inlet tract via the or each valve member.

Abstract: In the production of moulds for making moulded articles, e.g. foundry moulds for producing castings, it is known to consolidate resin-coated granular filler in a moulding box containing a pattern to form the mould pieces. A gas such as SO.sub.2 is passed through the filler to cause it to set. However, after repeated use, resin buildings up on the pattern plate. According to the invention, the pattern is provided with a layer of silicone release agent such as siloxane which prevents resin build-up yet can be easily washed away.

Abstract: A steerable wheel suspension system comprising: a hub suspended from the vehicle body by a spring and damper strut system, a steering arm extending outwards and forwards from a steering rack positioned relatively low down and behind the engine to a ball joint on the hub, a first linkage arm extending outwards and rearwards from a forwardly mounted bush on the vehicle body to a ball joint on the hub, and a second linkage arm extending outwardly and forwardly from a hinge pivot on the vehicle body to a pivot joint on the first linkage arm, the arrangement being such that during rearward compliance of the hub, e.g. during braking, the second linkage arm constrains the pivot and hence the ball joint to move along an arc which is matched with an arc along which the ball joint is constrained to move by the steering arm and so reduce or eliminate induced steer during rearward compliance.

Abstract: An inlet manifold 7 for both banks of cylinders of a V-configuration internal combustion engine has two different lengths of tuned inlet passage between a plenum 14 and an inlet valve 3. A first length extends from an opening 13a in one face (in this case the upper) of the plenum 14. A second length extends the first length when valve 13 closes the opening 13a, passes along passage 16 around the side of the plenum remote from the cylinder 2, and communicates with the other face (in this case the lower) via an opening 18. It is possible to construct such a manifold in three parts: a plastics moulding 10 defining the plenum 14; two metal pressings 8, 9 which engage each other; and a third metal pressing 11. Such a construction can be cheaper and lighter than hitherto.

Abstract: A distributor for a spark ignition internal combustion engine is driven via a drive spindle 3 which is held via a resilient bush 4 in a drilling in the end of a camshaft 1 of the engine which operates the usual valve gear. Advance and retard are performed electronically. The resilient bush protects the drive spindle 3 and rotor from vibrations of the camshaft.

Abstract: An internal combustion engine has an integral cylinder block, crankcase and sump structure made in two halves 1, 2. The material of the halves is chosen for lightness. The pressure pulsations in the cylinders are taken by long steel bolts 14, 15 which extend from the top of the cylinder head to a bearing structure comprising yokes (steel clamping members 8, 9 clamped together by traverse fasteners 12, 13) holding together the two main crankshaft bearing housing halves 6, 7 which are formed integrally with each half of the integral engine structure. The integral halves do not have re-entrants and can be produced simply by casting, pressing or moulding.

Abstract: A road wheel suspension includes a wishbone 13 which may be for a rear driven wheel. Fore-and-aft compliance is introduced into the suspension without the usual problems of steering by mounting the wishbone on the body via a link 15 which can pivot about a transverse axis. In one embodiment, the inner ends of the front wishbone arms are mounted at the bottom of (plate-shaped) link 15, which is apertured to allow the propshaft to extend through, and the inner ends of the rear arms are resiliently secured to cross-member 21. The link is pivotally mounted on the final drive casing 14 about a transverse axis. The wishbones are stiff as far as lateral deflections are concerned but compliant for fore-and-aft deflections, the latter feature promoting increased ride comfort.

Abstract: The invention is concerned with a control system for an air/fuel ratio measurement and adjustment system for an internal combustion engine. In order to limit operation of the measurement and adjustment system to occasions when adjustment is likely to be necessary, an altitude sensing system is provided and the air/fuel ratio measurement and adjustment system is operated in response to measurement of a change in altitude. Altitude measurement is by way of measurement of absolute pressure in the engine inlet manifold and relating the measured pressure to an expected inlet manifold pressure at sea level for the current conditions of throttle opening and engine speed.

Abstract: The invention is concerned with a control system for an air/fuel ratio measurement and adjustment system for an internal combustion engine. In order to restrict operation of the air/fuel ratio measurement and adjustment system to occasions when adjustment is likely to be necessary, it is desirable to operate the system at approximately daily intervals. The control system incorporates an ambient temperature sensor and an engine coolant temperature sensor and is arranged to operate the measurement and adjustment system when the engine is started if the engine coolant temperature does not exceed the ambient temperature by more than a predetermined amount.