Abstract: Conventional vapor-compression refrigeration systems modified for greater efficiencies by installation of a liquid refrigerant level sensor in the drain line after the condenser, the sensor activating a valve in the high pressure vapor line in communication with the refrigerant receiver or reservoir, and the drain line being trapped to prevent vapor in the reservoir from backing up into the condenser.

Abstract: The invention relates to diaphragm spring friction clutches in which the diaphragm spring is supported on a cover by tabs which extend through slots between the fingers of the diaphragm spring and are bent radially outwards on assembly over an adjacent arc of a fulcrum ring which is on the opposite side of the spring to the cover. To achieve firm clenching of the diaphragm spring and the fulcrum ring by the tabs, during the bending operation each tab is supported against radially inward movement where it extends through the spring slot while the fulcrum ring is supported against radially outward movement over those arcs which are gripped by the tabs.