Abstract: A device for supporting a workpiece 5 from a bench 4 in any required spatial position comprises two G-clamps 1 which are adjustably fixed to a metal tube 2 by clamping devices 3. Each of the devices 3 is operated by a single clamping screw having a handle 21 and when the clamping screw has been released, the device 3 can slide along, and turn about the axis of, the tube 2. Also, the clamp 1 can turn relative to the clamping device 3 about the axis of the clamping screw and about the axis of a pin 24 which is perpendicular to the axis of the clamping screw. This enables the workpiece 5 to be set in almost any desired position and orientation relative to the bench 4 and, when set, to be locked in its set position by tightening the two clamping screws by means of their handles 21. The device is therefore extremely versatile and it can, of course, alternatively be used to hold two workpieces in position relative to each other, for example while glued joints set.

Abstract: A variable-pitch marine propeller comprises helicoidal blades 6 each mounted on a hub 1 to freely pivot about radial axis 25 spaced in front, in the direction of rotation, of the center of pressure of the blade 6 whereby water pressure acting on the blade exerts a torque which tends to turn it about its axis in a direction to bring the surfaces of the blade into line with the flow of water over it. The axis 25 is also spaced behind, with respect to the direction of movement of the propeller through the water, a major portion of the pressure surface of the blade whereby, the resultant of the drag of the water exerts a torque which tends to turn the blade in an opposite direction. The shape and mass distribution of the blades relative to their pivot axes are also such that centrifugal effects tend to move the blades, in the absence of hydrodynamic forces, into a pitch equal to that of the helicoid.

Abstract: In order to make better use of the energy which is generated by the combustion of fuel and air in an internal combustion engine, such an engine is provided with a turbine through which the hot exhaust combustion gases are expanded to drive a power output shaft of the turbine, a compressor for compressing the air drawn into the engine, and passages extending in the engine around the combustion chamber or chambers through which pass the compressed air which is not used for combustion, this air extracting heat from the engine and being expanded through the turbine to assist the exhaust gases in driving the turbine output power shaft.