Abstract: A centrifugal pump comprises an impeller which rotates at the center of a volute casing. The open side of the casing is closed by means of a wear plate which is fixed relative to the casing and which has a central inlet opening. The impeller includes a rear plate and a plurality of curved blades radiating from an open central portion of the rear plate. An annular plate is fixed to the outermost edges of the blades at the inlet side of the impeller. A cylindrical sleeve extends in an axial direction from near the inner edge of the annular plate through the opening in the wear plate. The annular plate and sleeve protect the edge of the wear plate and impede grit and sand entering between the annular plate and around the opening and the wear plate causing wear when the pump is used to pump slurry containing grit or sand.

Abstract: An overspeed safety braking device comprising an input shaft, the speed of which is to be braked when it exceeds a limit value, a rotary friction brake having a fixed part and a rotary part, the input shaft being permanently coupled for rotation with the rotating part of the rotary friction brake, a control device for applying the brake, and centrifugal activated structure comprising a braking member which rotates with the input shaft when the speed is below the limit value, a weight pivotally mounted on the braking member and biasing spring coupled to the weight and arranged to bias the weight toward the axis of rotation of the shaft when the speed is below the limit value and away from the axis of rotation when the speed is above the limit value.

Abstract: A rack-and-pinion type hoist has an improved braking apparatus that includes a spring buffer, preferably hydraulic, carried by the cage of the hoist, a rotatable shaft also carried by the cage and positively engaged with a member extending along the mast so as to be driven in rotation by movement of the cage along the mast and connecting means for engaging the shaft and the buffer comprising a centrifugal governor driven by rotation of the shaft and operating, in response to rotation of the shaft in excess of a pre-determined rate of rotation, to provide positive drive to a linearly movable member, the movement of which is opposed by the buffer.