J-tool

a sleeve receptacle with a fitted, male element that has pins that fit into milled J-shaped slots on the sleeve. The short sides of the J-slots provide a shoulder for supporting weight on the pins of the male element. When the male element is lowered and turned relative to the sleeve, the pins slide in the slot towards the long side of the J, which is open-ended. The pins may thus be raised out, releasing weight that may be supported by the sleeve. The releasing procedure is called "unjaying the tool."