Abstract: A piston hank has an openable loop which is defined by a substantially U-shaped portion of a fastener body and part of a closure link which is pivotally connected to the fastener body. In a locked position, the closure link bridges the shanks of the U-shaped portion of the fastener body. The closure link comprises a spring actuated locking pin which is displaceable in a substantially straight groove and which, in the locking position, protrudes from an end of the closure link and which cooperates with a recess or hole formed in the fastener body. A release member is provided for displacing the locking pin into the closure link against spring action to a release position, in which release position the locking pin is disengaged from the recess or hole and the closure link can be swiveled open.

Abstract: A snap shackle has a generally U-shaped closure link, the shanks of which are bridged by at least a part of a fastener body. One of the shanks of the closure link is rotatably and displaceably mounted in the fastener body and the other shank is provided at one end with locking means for engagement with corresponding locking means in the fastener body. The first shank, which is rotatably and displaceably mounted in the fastener body is provided with a pressure surface means which, upon actuation, is displaceable towards the fastener body in order to displace the other shank end away from the fastener body, thereby bringing the locking means on the shank and on the fastener body out of engagement with each other in order to permit the closure link to swivel open relative to the fastener body.