SAFETY CYLINDER AND ROLL TONG APPARATUS HAVING THEREOF

摘要

The present invention relates to a safety cylinder capable of preventing a driving force from being lost due to leakage of fluid from a cylinder providing the driving force. The safety cylinder according to an embodiment of the present invention comprises: a tubular body member having a space accommodating a working fluid; an elastic rod member connected to the tubular body member to have inner space parts of the tubular body member divided into two sealed parts to be straightly moved to be inserted into or detached from the tubular body member; and a fluid supply unit connected to the tubular body member and making the working fluid come in and out the tubular body member. The fluid supply unit includes: a first passage formed to be connected with a first space part of the inner space parts divided into two parts of the tubular body member and making the fluid come in and out the first space part; a second passage formed to be connected with the second space part which is the other part of the inner space parts of the tubular body member divided into two parts, discharging a fluid provided for the second space part when the fluid is supplied to the first space part, and supplying the fluid to the second space when the fluid is discharged from the first space part; a driving unit connected with at least one among the first passage and the second passage, providing a driving force making the fluid come in and out for the first space part or the second space part, and coupled to the tubular body member; and an adjustment valve unit provided between at least one among the first passage and the second passage and the driving unit and adjusting the blocking of the first passage or the second passage.