Abstract: A gerotor pump has a pump body having a cavity for housing an outer rotor having an outer surface which slides on the surface of the cavity, and an inner surface with lobes projecting inwards of the outer rotor; and an inner rotor, which is fitted to a drive shaft having an axis of rotation, and has lobes which mesh with the lobes of the outer rotor. The inner rotor is divided into at least two lobed portions by cutting the inner rotor along a plane substantially perpendicular to the axis of rotation.

Abstract: An arrangement is disclosed which enables the variation of the working environment of a computer comprising a working memory, a central processor unit and a plurality of peripheral units including an external memory. The arrangement comprises a switch having a plurality of positions associated with respective working environments and a logic control device responsive to the switch to introduce a group of microprograms, programs forming the operative system and at least one application program associated with the selected position of the switch from the external memory into the working memory. The programs and microprograms introduced into the working memory then are used to control the peripheral units in such a manner to establish different groups of functions, each group specializing the computer for the selected environment.