Operating mechanism for rotary slips

Claim 1

IN ROTARY SLIP MECHANISM, THE COMBINATION WITH A SLIP BOWL THROUGH WHICH A PIPE MAY BE EXTENDED CENTRALLY AND SLIPS MOVABLY DISPOSED IN THE BOWL FOR MOVEMENT TO POSITIONS FOR COACTION WITH THE BOWL AND PIPE TO GRIPPINGLY ENGAGE THE PIPE AND TO RELEASING POSITIONS OUT OF SUCH ENGAGEMENT, OF MEANS FOR MOVING THE SLIPS FROM ONE TO THE OTHER OFF SAID POSITIONS, SAID MEANS INCLUDING AN ANNULAR LIFTING RING VERTICALLY SPACED FROM THE TOP OF THE SLIP BOWL AND RECIPROCABLE RELATIVE THERETO AND LINKAGE MECHANISM OPERATIVELY CONNECTING THE LIFTING RING TO EACH OF SAID SLIPS, SAID LINKAGE MECHANISM COMPRISING A BELL CRANK LEVER HAVING ONE END PIVOTALLY CONNECTED TO ONE OF SAID SLIPS, A HINGE LINK PIVOTALLY CONNECTING THE OPPOSITE END OF SAID LEVER TO THE SLIP BOWL, AND A CONNECTING LINK PIVOTALLY CONNECTING AN INTERMEDIATE PORTION OF THE BELL-CRANK LEVER TO SAID LIFTING RING, SAID BELL-CRANK LEVER HAVING SPACED APART WEB PORTIONS DISPOSED IN PARALLEL PLANES RIGIDLY CONNECTED TOGETHER INTERMEDIATE THEIR ENDS AND EACH FORMED WITH LONGITUDINALLY SPACED, LATERALLY THICKENED HUB PORTIONS EACH HAVING A BORE THERETHROUGH, THE BORES OF THE HUB PORTIONS ON ONE WEB BEING ALIGNED AXIALLY WITH THE BORES OF THE CORRESPONDING ONES OF THE HUBS ON THE OTHER WEB, PINS EXTENDING BETWEEN THE WEBS AND INTO THE ALIGNED BORES, SAID PINS PROVIDING SAID PIVOTED CONNECTIONS BETWEEN SAID LEVER AND THE OTHER ELEMENTS OF SAID LINKAGE MECHANISM, AND MEANS CONNECTING THE PINS TO THE HUB PORTIONS TO HOLD THE PINS AGAINST ROTATIONAL AND AXIAL MOVEMENT IN THE BORES.