a first connection structure 44 fig2 and a second connection structure 46 both disposed on the first end cap 34 and a third connection structure 50 and a fourth connection structure 54 both disposed on the second end cap 38 the connection structures 44 46 50 54 are projections that extend axially inwardly from the first and second end caps 34 38 the safety mechanism 42 further includes a first cable 58 coupled to both the first connection structure 44 and the third connection structure 50 and a second cable 62 coupled to both the second connection structure 46 and the fourth connection structure 54 in some constructions the cables 58 62 are releasably coupled to the connection structures 44 46 50 and 54 such that they may be removed or replaced as desired in some constructions ends of each of the cables 58 62 are coupled to the connection structures 44 46 50 54 via frictional fit welding adhesion fasteners or are formed integrally as one piece with the connection structures 44 46 50 54 in the illustrated construction each of the cables 58 62 is made of a fiber e g woven material that has a stretch capability that will allow it to absorb the impact energy of the spring 30 with continued reference to fig1 3 in the illustrated construction the first and second cables 58 62 wrap helically about the outer body 22 and the axis 22 and act as tethers to prevent or inhibit the moving e g expanding spring 30 outer body 22 or any other structure from damaging nearby components or people in other constructions only a single helically wound cable is used or more than two helically wound cables are used in some constructions at least a portion of each.