Abstract: An extra short transmission shaft has two telescopically fitted tubular shaft sections (6,7) having diameters (D',D) substantially greater than the basic diameters of coupling forks (8,9) associated with respective ends of the shaft sections. The increased diameters of the shaft sections ensure a greater torque transmitting contact area between meshed teeth formed on such sections, this strengthening the coupling formed thereby and/or permitting the length of the meshed teeth, and thus of the shaft itself, to be reduced to a minimum without unduly affecting the coupling strength. Preferably, each of the coupling forks is integral with the free end of its respective shaft section.

Abstract: A speed limiting device for vehicles is described in which an actuator is responsive to a vehicle speed sensor to reduce air and fuel supplies to the vehicle engine when a predetermined vehicle speed is reached. The possibility of the vehicle driver overriding the device from the driver's position is eliminated by making electrical connections to supply power for the device direct to the vehicle's battery, and by inserting in the accelerator pedal linkage an compressible elastic strut which limits the force exertable on the throttle linkage by the driver.