Patent ID: 7555978
Filing Date: 2009-07-07
Classification: F15B

Abstract:
1. Hydraulic actuating device comprising: a first hydraulic actuator, which actuator has a housing containing a cylinder space in which a piston/piston rod assembly is accommodated in such a way that it can move axially to and fro between corresponding first and second end positions, which piston/piston rod assembly projects out of the housing, in which, in the cylinder space, the piston/piston rod assembly bounds a first chamber and second chamber, which chambers have a volume that depends on the position of the piston/piston rod assembly, the volume of the first chamber being at its smallest when the piston/piston rod assembly is situated in the first end position, and the volume of the second chamber being at its smallest when the piston/piston rod assembly is situated in the second end position, in which the housing is provided with a first and a second connection for the supply and discharge of hydraulic fluid, which connections are in communication with the first and the second chamber, respectively, by way of a first and a second opening, respectively, in the cylinder space, a second hydraulic actuator, which second actuator has a housing containing a cylinder space in which a piston/piston rod assembly is accommodated in such a way that it can move axially to and fro between corresponding first and second end positions, which piston/piston rod assembly projects out of the housing, in which, in the cylinder space, the piston/piston rod assembly bounds a first chamber and second chamber, which chambers have a volume that depends on the position of the piston/piston rod assembly, the volume of the first chamber being at its smallest when the piston/piston rod assembly is situated in the first end position, and the volume of the second chamber being at its smallest when the piston/piston rod assembly is situated in the second end position, in which the housing is provided with a first and a second connection for the supply and discharge of hydraulic fluid, which connections are in communication with the first and the second chamber, respectively, by way of a first and a second opening, respectively, in the cylinder space, in which damping means are provided for providing a damping of the speed of movement of a piston/piston rod assembly, wherein the first opening of the second hydraulic actuator is in communication with the first opening of the first hydraulic actuator; the second opening of the second hydraulic actuator is in communication with the second opening of the first hydraulic actuator via a third connection to the housing of the first hydraulic actuator, the third connection being in communication with the cylinder space in the first hydraulic actuator via a third opening; and the damping means are achieved by the fact that the piston/piston rod assembly of the first hydraulic actuator is provided with a throttle means, which, during movement of the piston/piston rod assembly from the first to the second end position, is designed to restrict the outflow of hydraulic fluid via the second opening before the piston/piston rod assembly reaches the second end position, in which, in addition to the first hydraulic actuator, the second hydraulic actuator is also provided with damping means which are achieved by the fact that the piston/piston rod assembly is provided with a throttle means, which is designed to restrict the outflow of hydraulic fluid via the first opening during movement of the piston/piston rod assembly from the second to the first end position before the piston/piston rod assembly reaches the first end position, and in which the first opening of the second hydraulic actuator is in communication with the first opening of the first hydraulic actuator via a third connection to the housing of the second hydraulic actuator, the third connection being in communication with the cylinder space in the second hydraulic actuator via a third opening.