Spring cramp, particularly for axle springs of motor vehicles

A cramp for a coiled spring comprising a guide tube, first and second slide members relatively movably mounted on said guide tube, means associated with said guide tube for moving said slide members relatively, a clamping jaw carried by each of said spring members arranged in opposite facing arrangement for engaging the spring at successive coils arranged therebetween, each jaw member having a median plane and a circularly extending leg on each side of said median plane and with a continuous oblique spring coil contact surface for engaging respective spring coils, a circularly cylindrical outer wall extending outwardly in an axial direction toward the respective other clamping jaw from and bounding the radial outer side of said contact surface, an axially projecting backing rib bounding the inner edge of said contact surface and having a circumferential extension such that it extends at least from 30.degree. up to 100.degree. of arc measured from the center of said jaw, said backing rib being cylindrical relative to said median plane, said legs having end portions adjacent their ends which are 11/2 to 2 times wider than its central portion between said end portions, said contact surface being arcuate through 180.degree. and having substantially parallel edges beyond 180.degree..