Abstract: A device is provided for a screw connection between two pieces which can adjust the distance between the two pieces. The device comprises a first threaded piece and a second smooth piece with an annular groove close to its free end. A connector ring is screwed onto the threaded shank and engaged on the smooth piece. The connector ring has a groove of variable depth. An incompressible retaining ring is engaged in the grooves of the second piece and the connector ring. The device can be used to produce a single tension element.

Abstract: A snap shackle has a body formed on one side with an attachment such as a swivel eye and on the other side with a C-shaped arm having an outer end forming a pivot for a complementarily shaped pivotal arm whose free end in turn is engageable against the shackle body to form another eye. A latch constituted as a stirrup pivotal about an axis parallel to the pivot axis of the pivotal arm is mounted on the shackle body and has a bight that can engage in a holding position over the free end of the pivotal arm to hold it in a closed position. This arm can be springy in such a manner that it seeks the holding position, or can be biased by a spring into the holding position. A trip line attached to the stirrup can displace it into a freeing position in which it allows the pivotal arm to swing away from the body and open up the shackle.