Abstract: An absorption dynamometer includes a rotor (12) and restrained stator means (14), and in use of which the rotor energy is substantially dissipated as heat in the stator means. A cooling arrangement (16) for the stator means comprises passage means (62,63) for coolant fluid. This passage means extends, at least in part spirally, from a fluid intake port (70) at or adjacent a first end of the stator means to an oultet outlet port (71) at or adjacent a second end of the stator means. Also disclosed is a vibration absorption means (25) and flexible coupler means (84,85) to dampen the vibrations of a power tool being tested.

Abstract: A reciprocatory machine having a cylinder defining with at least one piston a working chamber. Each piston is reciprocable in the cylinder by a respective crankshaft. The machine has intake and exhaust ports disposed at opposite ends of the working part of the cylinder and has respective valves additional to the pistons for opening and closing the ports. The valves are driven by the crankshaft(s) and have provision for adjusting the timing relationship between the displacement of the crankshaft(s) and the valves and thereby the timing relationship between the respective valves. The location of the ports at opposite ends of the working part of the cylinder permits considerably greater adjustment of the timing than is possible with conventional closely spaced porting arrangements. The machine preferably operates as a two-stroke internal combustion engine but may also operate as a pump or compressor.

Abstract: An improved infinitely variable speed epicyclic drive mechanism having planet discs which are supported by a carrier and revolve on a track determined by a pair of sun discs and matching non-rotating peripheral annular members. In one embodiment, the planet discs are each rotatable in an arm or fork in turn rotatable in the carrier and means is provided to reduce centrifugally induced axial forces occuring between the planet discs and the surrounding annular members. In a further embodiment the sun discs are torque sensitively loaded towards each other for frictionally engaging the planet discs by helical gears in an epicyclic gear train to which the mechanism is coupled.