Abstract: A securing device for securing in cavaties and comprising a number of clamping jaws (11), provided under influence of a changeable tension body (21) to expand against opposite wall portions (13) in said cavity. The clamping jaws (11) have engagement surfaces (12) which are forced outwards and tension surfaces provided to cooperate with a tension surface (22) of the tension body. By means of a displacement motion of the clamping jaws relative to the tension body is brought to adjust the clamping jaws between an inner releasing position, and an outer expanded securing position. The device comprises a spring mechanism (4) provided to press the clamping jaws (11) in direction against the tension body (21). Between the clamping jaws and the tension body a distance element (20) is positioned being provided to maintain in its releasing position a predetermined distance between a support surface (19) of each clamping jaw and a surface (23) of said distance element.