Retractable rock hole pin

Claim 1

A RETRACTABLE ROCK HOLE PIN COMPRISING A GENERALLY CYLINDRICAL MEMBER HAVING ENDS AND A WEDGE-SHAPED CUTOUT FORMED IN A PORTION OF THE SURFACE THEREOF, SAID CUTOUT BEING DISPOSED LONGITUDINALLY AND INTERMEDIATE THE ENDS OF SAID MEMBER AND HAVING A SURFACE INCLINED WITH RESPECT TO THE LONGITUDINAL AXIS OF SAID MEMBER, SAID INCLINED SURFACE HAVING A SLOT BEING T-SHAPED IN TRANSVERSE CROSS-SECTION FORMED LONGITUDINALLY THEREIN, SAID TSHAPED SLOT TERMINATING SHORT OF THE AXIS OF THE ENDS OF THE WEDGE-SHAPED CUT-OUT, A TAPERED BARB HAVING A COMPLEMENTARY INCLINED SURFACE AND SLIDABLY LOCATED IN SAID CUT-OUT, SAID BARB HAVING A T PIN PROTRUDING OUTWARDLY FROM SAID INCLINED SURFACE FOR REMOVABLE AND SLIDING ENGAGEMENT WITHIN SAID SLOT, SAID PIN HAVING A T-SHAPED CROSS-SECTION WITH THE CROSS PORTION OF THE T BEING GENERALLY TRANSVERSE TO THE LONGITUDINAL AXIS OF THE BARB, SAID T-SHAPED CROSS-SECTION HAVING A TRANSVERSE DIMENSION LESS THAN THE CORRESPONDING PARTS OF THE SLOT, THE LONGITUDINAL THICKNESS OF THE T PIN BEING SLIGHTLY LESS THAN THE WIDTH OF THE NARROWEST PART OF THE T-SHAPED SLOT THEREBY PERMITTING INSERTION OF THE T PIN IN THE T-SHAPED SLOT WHEN THE LONGITUDINAL AXIS OF THE TAPERED BARB IS DISPOSED TRANSVERSE TO THE LONGITUDINAL AXIS OF SAID CYLINDRICAL MEMBER AND PERMITTING TURNING OF THE BARB TO ITS NORMAL POSITION ALONG THE WEDGE-SHAPED CUT-OUT ANCHORAGE MEANS SECURED TO ONE END OF TGHE CYLINDRICAL MEMBER AND A RELEASE CABLE SECURED TO ONE END OF THE BARB FOR SELECTIVELY RETRACTING THE SAME INTO SAID CUT-OUT.