Piston-cylinder assembly
OwnerKurt Stoll, Gerhard Hihninventors
Life of this patent
Estimating the term…
Abstract
A piston-cylinder assembly wherein in the cylinder housing there is provided a cylinder chamber extending in axial direction, in which cylinder chamber a piston is movably guided in axial direction. Both the piston and also the cylinder chamber have a cross section which is different from a circular shape. A permanent-magnet piece is arranged fixedly in the area of the outer circumference of the piston. A switch arranged in the area of the linear path of movement of the permanent-magnet piece is provided on the outside on the cylinder housing, which switch can be operated without contact by the magnetic field of the permanent-magnet piece.
Claims12
A piston-cylinder assembly, comprising:
- `an elongated cylinder housing made of nonmagnetic material and including means defining an inner cylinder chamber extending in an axial direction thereof, said inner cylinder chamber having noncircular cross section while an external surface thereof is of a nonconforming shape in cross section so as to define at least one region on said cylinder housing wherein a wall thickness dimension is thinner than at other locations, said region being located on a radial axis of said cylinder housing;
- a piston made of nonmagnetic material and conformed in shape to and non-rotatably received in said inner cylinder chamber, said piston being movable in axial direction in said inner cylinder chamber and guided by a noncircular guide surface formed by a side wall of said inner cylinder chamber;
- means defining a recess in an outer peripheral surface of said piston, said recess being located generally on an axis radially aligned with said radial axis of said cylinder housing;
- at least one magnet received in said recess;
- said inner cylindrical chamber and said piston being both oval in cross-sectional shape, said recess in said piston being located on a major axis of said oval, and said region whereat said wall thickness is thinnest being located on said major axis of said oval;
- at least one switch mounted on an exterior surface on said cylinder housing and arranged within range of the magnetic field of said magnet when said cylinder housing and said switch are generally radially aligned, said switch being operable when present in a magnetic field, whereby said switch is operated by said magnetic field of said magnet when said piston and said switch are generally radially aligned, said noncircular and conforming cross-sectional shapes of said inner cylinder chamber and said piston thereby defining a means for preventing said piston and said cylinder housing moving angularly with respect to each other to maintain a fixed radial alignment relation of said magnet and said switch.
Dependencies are inferred from the claim text.