Abstract: A rack and pinion steering gear assembly 10 includes a rack 14 which is movable relative to a housing 12 to turn steerable vehicle wheels. The rack 14 extends through a bellows 34 which is connected with an end portion of the rack 14 and an end portion of a housing 12. A deformable and compressible body 40 of foam material is located in the bellows 34. The deformable and compressible body 40 of foam material includes a body 70 of closed-cell foam 10 material and/or a body 66 of open-cell foam material. The body 70 of closed-cell foam material retards conduction to the rack 14 of any water which may leak through the bellows 34. The body 66 of open-cell foam material contains lubricating liquid which is applied to the rack 14. If desired, the bellows 34 and deformable and compressible body 40 of foam material may be used in an apparatus other than a rack and pinion steering gear assembly.

Abstract: A vehicle speed control system comprises a memory which stores a signal Vr representing desired road speed which is compared in a comparator with a signal Vs representing actual speed. An actuator responds to any error by adjusting the engine to bring the vehicle to the correct speed. Units are provided to enable the driver to increment or decrement the stored desired speed by small amounts (e.g. 0.5 miles per hour). By means of switches, he can switch into the memory either one of two preset desired speed values. He can also modify these present values, by feeding in, instead, the actual road speed of the vehicle, such modified preset values remaining until the engine is next switched off. The system incorporates a "SOFT OFF" feature, by which, under certain switch off modes of the system, the engine power is not shut off abruptly but at a controlled rate. The system is advantageously implemented by means of a microprocessor.

Abstract: An indicator panel 20 has an array of LED's 25A to 25Q to provide an indication to the driver of a road vehicle, particularly a diesel-powered truck, when he should change to the next highest gear during acceleration from rest or low speed. The LED's are lit progressively as the engine speed increases in each gear and, when lit, emit green light if the engine speed is below the optimum change-up speed for that gear. When the engine speed begins to exceed the optimum change-up speed, the next LED illuminated produces red light to the driver. An audible warning may also be produced. If the driver does not change up in response to such warning, further red LED's will show and a more strident audible warning may be given. The change-up speeds to which the system responds are pre-set so as to be the optimum speeds for increased fuel efficiency. The change-up speed corresponding to the lowest gear is relatively low and increases successively for the successively high gears.

Abstract: An actuator which forms part of speed control apparatus for controlling the forward speed of a vehicle, or the rotational speed of an engine, where it is desired to bring the speed control apparatus into operation at the discretion of the operator, has a reversible electric motor which receives a speed correction signal related to the difference between the actual speed and the desired speed. An electromagnetic clutch is provided which includes a rotor driven by the motor, and a clutch ring mounted via a spring from a pulley having a double-acting connection to the throttle lever of the engine. The clutch is energized on engagement of the speed control to bring the rotor and clutch ring into driving engagement, whereby the throttle lever is driven by the electric motor via the pulley and double-acting connection.At any instant, the position of the clutch ring and pulley corresponds with that of the throttle lever.