Rigid chain actuator

High-capacity rigid chain lifting columns (jacks) can move dynamic loads exceeding 10 tonnes (22,000 lb) over more than 7 metres (23 ft) of travel.

The links of the actuating member, the “rigid chain”, are articulated in a manner that they deflect from a straight line to one side only.

Because the actuating member can fold on itself, it can be stored relatively compactly in a storage magazine, either in an overlapping or coiled arrangement.

Small scale rigid chain actuators are used as building hardware, incorporated into windows, door and hatches as motorized open/close mechanisms.

Robert Matthews received a US patent for his “Mechanical Rammer” in 1901 which used a roller on the leading end of the chain to guide it and allow thrust without deflection.

An early conception of chain used as a telescoping column instead a horizontal rammer was by Eldridge E. Long, who was awarded a US patent for his “Lifting Jack” in 1933, which he believed was “particularly adapted for use upon automobiles”.