Patent ID: 9637364
Date: 2017-05-02
CPC Classifications: B66F

Claim:
1. A car lift for motor vehicles, comprising a first lift element and a second lift element, the first lift element having a first hydraulic cylinder/piston assembly and the second lift element having a second hydraulic cylinder/piston assembly for lifting a motor vehicle, with each of the first hydraulic cylinder/piston assembly and the second hydraulic cylinder/piston assembly comprising a cylinder and a piston with a piston gasket, the cylinder having an inlet connected to an interior chamber at a first side of the piston for feeding hydraulic fluid into the piston when lifting the motor vehicle and a discharge connected to said interior chamber at a second side of the piston for draining hydraulic fluid displaced by said piston when lifting the motor vehicle, and the first hydraulic cylinder/piston assembly being a master assembly, with the discharge thereof being fluidly connected to the inlet of the second hydraulic cylinder/piston assembly which acts as a slave assembly, at least one of the first hydraulic cylinder/piston assembly or the second hydraulic cylinder/piston assembly includes a solid material cylinder wall having a defined material thickness at least in areas of end positions of the piston, said cylinder wall having an inner surface defining an interior chamber of the cylinder, an overflow channel formed by a recess or groove in the inner surface of the cylinder wall positioned at the interior chamber of the cylinder of said at least one of the first hydraulic cylinder/piston assembly or the second hydraulic cylinder/piston assembly, the recess or groove staying within the defined material thickness of the cylinder wall and is arranged such that only in an area of the end positions for the piston that is maximally extended when a vehicle is maximally raised or maximally lowered, the inlet and the discharge of said at least one of the first hydraulic cylinder/piston assembly or the second cylinder/piston assembly with the overflow channel are fluidly connected.