Patent ID: 8794932

Claim:
A hydraulic lift device, comprising: a hydraulic cylinder having a first cylindrical sleeve slidably coupled to a second cylindrical sleeve, the first and second cylindrical sleeves further having a hollow channel to accommodate passage of a polished rod associated with a subterranean well, the first cylindrical sleeve further comprising a surface for securing a portion of the polished rod; a port in fluid communication with the hollow channel, the port being configured to receive an inlet line from a hydraulic pump; a guidance system disposed at least partially outside of the hydraulic cylinder, wherein the guidance system is configured to prevent axial rotation of the first cylindrical sleeve with respect to the second cylindrical sleeve; and a sensor system comprising a piston rod with an end of the piston rod slidably received inside a non-cushion tube, wherein an overall length of the hydraulic cylinder is configured to increase as hydraulic fluid is pumped into the first cylindrical sleeve, causing the second cylindrical sleeve to slidably translate with respect to the first cylindrical sleeve.