Patent ID: 7938473
Filing Date: 2011-05-10
Classification: B60J,E05F,E05Y,Y10T

Abstract:
1. An electromechanical strut for moving a pivotal lift gate between an open position and a closed position relative to a motor vehicle body, the electromechanical strut comprising: a housing connected to one of the lift gate and the motor vehicle body, the housing including a stationary guide tube; an extensible member slidably mounted to the housing and connected to the other of the lift gate and the motor vehicle body, the extensible member including spaced apart outer and inner tubular walls defining a toroidal chamber therebetween and a radially inner interior chamber, the stationary guide tube extending into the toroidal chamber adjacent the inner tubular wall of the extensible member; at least one coil spring disposed within the toroidal chamber and coupled between one end of the extensible member and the housing for providing a mechanical counterbalance to the weight of the lift gate, wherein a radially inner edge of the at least one coil spring is guided by the stationary guide tube and a radially outer edge of the at least one coil spring is guided by the outer tubular wall of the extensible member; a motor-gear assembly mounted in the housing; a rotatable power screw connected to and driven by the motor gear assembly, the power screw extending into the radially interior chamber of the extensible member; and a drive nut fixedly mounted in the interior chamber of the extensible member, the drive nut threadingly engaging the power screw; whereby the motor gear assembly converts rotary motion of the power screw into linear motion of the extensible member to move the extensible member between a retracted position corresponding to the closed position of the lift gate and an extended position corresponding to the open position of the lift gate.