Abstract: A grinder pump with a self aligning cutter assembly, the grinder pump having an inlet port, a drive shaft and a cutter assembly, the cutter assembly comprising a rotary cutter and a stationary, annular cutter. The rotary cutter is supported for rotation by the drive shaft, and the annular cutter is supported in the inlet port. The rotary cutter has a pair of primary knife members with knife edges, and the annular cutter is supported in the inlet port, the annular cutter having a central bore in which a plurality of internal cutting edges are formed. The rotary cutter is supported in the central bore so its primary knife members are rotated in operational cutting engagement with the internal cutting edges by the drive shaft. The annular cutter is provided a limited range of radial movement and is positioned within the range of movement by the rotary cutter.

Abstract: In a vehicle mounted digger derrick or crane, the moment applied to the boom by a lift cylinder is controlled in a customized manner to more fully utilize the structural strength of the machine at different working positions of the boom. In one embodiment, the moment is controlled by controlling the moment arm through a pivot link which carries the base end of the lift cylinder and which is pivoted by an auxiliary cylinder. In another embodiment, the force component of the moment is controlled in response to changes in the boom angle or moment sensed by a linear position transducer or other sensor.