Method of producing a shear resistant captive screw

Abstract

Abstract A CAPTIVE SCREW INCLUDING A SLEEVE HAVING A BORE SUBSTANTIALLY COMPLEMENTARILY RECEIVING A RELATIVELY LARGE DIAMETER PORTION OF THE SHANK OF A SCREW INWARDLY OF THE SCREW HEAD, WITH AN ANNULAR ENLARGEMENT ON THE SHANK, OF GREATER FIAMETER THAN THE BORE, BEING LOCATED AT THE END OF DHIS SHANK PORTION AND RETAINING THE SCREW OT THE SLEEVE. BEYOND THE ANNULAR ENLARGEMENT, THE SHANK IS PROVIDED WITH AN ANNULAR GROVE AND ROLLED THREADS ON ITS OUTER END. THE SLEEVE INCLUDES A HEAD AT ONE END AND AN ENLARGED BOER PORTION AT THE OPPOSITE END PROVIDING A RELATIVELY THIN WALL ADAPTED TO BENT OUTWARDLY TO SECURE THE SLEEVE TO A WORKPIECE. THE FASTENER IS PRODUCED BY FIRST PROVIDING A SCREW BLANK HAVING A HEAD AND PORTIONS OF TWO DIAMETERS, THE LARGER DIAMETER PORTION BEING EXTENDED THROUGH THE SLEEVE, FOLLOWING WHICH DIES ARE ENGAGED WITH THE BLANK AT THE JUNCTURE OF THE SMALLER AND LARGER DIAMETER PORTIONS, PRODUCING AN ANNULAR GROOVE AND DISPLACING MATERIAL OUTWARDLY INTO RECESSES IN THE DIES WHERE THE ANNULAR ENLARGEMENT IS SHAPED. A BULGE ON THE SMALLER DIAMETER PORTION OF THE SHANK ALSO IS CREATED WHEN THE GROOVE IS FORMED, WHICH THEN IS GROUND OFF, AFTER WHICH THREADS ARE ROLLED ON THE END PORTION OF THE SHANK.

Inventors

• 👤 Bulent Gulistan

Bibliographic Details