Abstract: A can opener includes a pair of pivoted handle members (101), (102), associated with a drive wheel (108) and a cutting wheel (111), which are brought into a position to nip the rim of a can when the handles are closed. The nip on the can is not lost when the handle members are partially opened to an intermediate position. As shown the cutting wheel is pivotally mounted on a rotatable carrier (112) in the handle (101) and has a projection (104) entering a recess (105) in the handle (102). The recess allows the handle (102) to move between the closed and intermediate positions without disturbing the carrier (112). Closing the handle (102) drives a drive shaft (110) carrying the wheel (108) through gearing (153), (154), (155). A one-way clutch spring (116) slips when the handles open so that repeated opening and closing of the handles cuts round the can.

Abstract: In apparatus for the reverse osmosis purification of water or other fluid in a module containing a membrane, the water is forced into the module under pressure using two piston-cylinder assemblies mechanically interconnected with the pressurized fluid from the module applied to the rear face of the piston which, from its front face, is driving water into the module, a low pressure continuously operating pump providing a low pressure on the other piston to supply the necessary extra pressure. Valve means automatically reverse the functions of the two cylinders at each end of each stroke.

Abstract: Apparatus for reverse osmosis purification of water or other fluid by passing the fluid under pressure across a membrane, through which membrane a part of the fluid passes in purified form, makes use of a piston or diaphragm pump in which the front face of the piston or diaphragm is used to force the fluid from one end of a cylinder into the module and in which the return fluid is applied to the rear face of the piston or diaphragm so that the pressures on the two faces are substantially balanced. The piston or diaphragm is operated by a piston rod attached to the rear face of the piston or diaphragm; the system is self-regulating to give an extraction ratio equal to the ratio of piston rod area to piston area.