Patent ID: 11953033
Assignee: BUEMACH ENGINEERING INTERNATIONAL B.V.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A working cylinder with cushioned end-stroke, comprising:
a cylinder having a cylinder tube with an inner cylinder wall, a first closure part and a second closure part, the cylinder tube having a first cylinder tube end and a second cylinder tube end, the first closure part being arranged at the first cylinder tube end and the second closure part being arranged at the second cylinder tube end, the cylinder tube and the closure parts defining a cylinder interior with an axial boundary, the cylinder having a damping zone at one of the tube ends, the cylinder having at least one laterally arranged pressure medium connection associated with the damping zone and being axially spaced the axial boundary;
a piston unit having a piston main part with a guiding pin, the piston unit having a ring body with a radial outer lateral surface, a ring opening, and a piston main part side with an axial ring surface and, opposite said axial ring surface, the piston main part having an axial counter ring surface on a ring body side thereof, the ring body having a circumferential inner ring groove on the radial outer lateral surface, the ring body receiving the guiding pin in the ring opening;
a ring gap being defined between a radial inner lateral surface of the ring body and the guiding pin, the ring body having an axial play and a radial play with respect to the piston main part,
the piston unit slidingly passing through the first closure part and defining at least one working chamber in the cylinder interior, the piston main part being guided in an axially displaceable manner by a guide in the cylinder interior;
a piston ring disposed in the inner ring groove, the piston ring resting resiliently against the inner cylinder wall and having a piston ring gap;
the piston unit constructed for axially passing over the pressure medium connection with the piston ring during an inward movement into the damping zone and enclosing a damping pressure medium volume in a damping zone space in the damping zone, the piston unit constructed for being in a first operating state within the damping zone during inward movement and in a second operating state during outward movement;
in the first operating state, the axial ring surface and the axial counter ring surface abutting against each other and defining a sealing plane, the damping pressure medium volume having an overpressure compared to the pressure medium connection, and the piston ring gap being configured for a throttled outflow of the damping pressure medium volume;
in the second operating state, an axial gap exists between the axial ring surface and the axial counter ring surface, the axial gap and the ring gap defining a pressure medium inlet channel configured for an inflow of a pressure medium into the damping zone space.