Patent ID: 10173872

Abstract:
A lift system includes a cylinder having an end surface, a threaded member supported for movement with a piston, and a nut threadedly engaging the threaded member and selectively engageable with the end surface. Engagement of the nut and the end surface limits axial movement of the piston relative to the cylinder in at least one direction. A drive mechanism rotates the nut relative to the threaded member, and a control valve controls movement of the piston relative to the cylinder. A drive control mechanism controls operation of the drive mechanism and rotation of the nut. A nut sensor senses a portion of the nut. The nut sensor is in communication with at least one of the control valve and the drive control mechanism. When the nut sensor detects a portion of the nut, the control valve stops movement of the piston or the drive control mechanism stops rotation of the nut.