Abstract: The invention relates to a device for transferring heat and a method of controlling such a device, the device comprising a stator chamber containing: a liquid; an input heat exchange surface; an output heat exchanger; and a rotor arranged to be rotated by vapour bubbles.

Abstract: The invention is a compression method having characteristics of smooth compression and internal cooling of the gas. Embodiments of the invention employ a cylindrical chamber and an orbiting rotor to create a moving duct or chamber whose walls converge, relative to a static gas packet drawn into the moving duct, at a “pinch point”. Preferably the closing speed of the walls is subsonic and the speed of the pinch point is supersonic. This enables high pressure to co-exist, at the narrowing end of the duct, with low pressure elsewhere in the duct, because of the pressure information barrier produced by the supersonic advance of the pinch point. The invention also discloses means for providing gas inlet and outlet functionality, and means for providing a variable flow compressor.

Abstract: A coil spring 10 having a plurality of windings 12, at least two of the windings 12 being hinged together.

Abstract: A variable speed drive comprising two drives, an output drive wheel and an endless, extendible member that is driven by the drives and extends around and rotates the output drive wheel. The drives are operable to move the endless member around an endless path at a first speed at a first driving position and at a second speed at a second position. This causes local expansion or contraction of the endless member around the output drive wheel and so varies its speed.

Abstract: A variable speed drive comprising two drives, an output drive wheel and an endless, extendible member that is driven by the drives and extends around and rotates the output drive wheel. The drives are operable to move the endless member around an endless path at a first speed at a first driving position and at a second speed at a second position. This causes local expansion or contraction of the endless member around the output drive wheel and so varies its speed.

Abstract: A variable speed drive comprising two drives, an output drive wheel and an endless, extendible member that is driven by the drives and extends around and rotates the output drive wheel. The drives are operable to move the endless member around an endless path at a first speed at a first driving position and at a second speed at a second position. This causes local expansion or contraction of the endless member around the output drive wheel and so varies its speed.