GB786644A - Improvements relating to fasteners - Google Patents

Abstract

786,644. Stud and socket fastenings; bolts &c. DZUS FASTENER EUROPE, Ltd. Nov. 21, 1955 [Nov. 26, 1954], No. 34384/54. Classes 44 and 89(1) A fastener for releasably securing together two articles or parts 11, 20, comprises a screw-threaded stud member 1 having a head 3 at one end, a bearing member 9 with a seating for the head for connection to one of the articles or parts, an anchoring member 18 for connection to the other article or part, both the bearing member and the anchoring member having openings for the stud member to pass through and one of the members having a tapering spigot 16 and the other a co-operating socket 17, and an internally screwthreaded collar carried in a housing 30 on the anchoring member, the collar being prevented from rotating by the housing but having a part-spherical bearing surface 23 which co-operates with a seating 24 on the anchoring member, with the result that the end of the stud member can be engaged in the collar without first aligning the openings in the bearing member and the anchoring member and on screwing the stud member into the collar, the spigot is pressed into the socket and the openings are drawn into alignment. The anchoring member carries a resilient bar 27 which is engageable with a cam slot 4 in the stud member, engagement and disengagement being effected by rotating the stud member relative to the bar. The resilient bar is carried by the collar which consists of two parts 21, 22 which closely fit together, the resilient bar being connected to ears 26 of the part 21. The collar part 21 has the part-spherical bearing surface 23. The collar is held in position on the seating 24 which is conical in shape by the housing 30 which extends from the anchoring member 18 around the collar, the uppermost edge of the housing being swaged over after the collar has been inserted and bearing on a part-spherical seating 32 on the part 22 of the collar. The housing is formed with two diametrically opposite slots 33 through which the ears 26 on the part 21 of the collar pass with a small clearance so that the resilient bar is free to rock. A light coil spring 34 bears on the anchoring mem- 'ber 18 and on the underside of the ears 26 to maintain the bearing surface 23 slightly clear of the conical seating 24. The head of the stud member 1 has a part-spherical bearing surface 12 which seats on a conical seating 13 of the member 9 so that the stud member can also rock relative to the member 9 through a small angle. The stud member is formed with a two start screw thread 5 adjacent the cam slot 4 and the faces of the screw thread are cut to unequal angles so that the face 6 which faces the head is of greater area than the other face 7. The portion 8 of each screw thread adjacent the head 3 is cut so that it forms part of the surface of a cone. When the stud member is inserted into the opening in the anchoring member 18 its screw thread 5 engages a corresponding thread 25 in the collar part 21 and thus forces the spigot 16 into the socket 17 and aligns the member 9 with the anchoring member 18. Further rotation of the stud member causes the thread 5 to travel completely through the collar part 21 until the conical portions 8 of the thread 5 bear on corresponding conical surfaces 37 between the starts of the thread 25. This prevents rotation of the stud member when tension is applied to it. The rotation of the stud member also engages the cam slot with the resilient bar and locks the stud member in position with the spigot 16 completely drawn into the socket 17. The stud member is loosely secured to the member 9 after it has been inserted through the aperture in it by means of a circlip 14 inserted into a groove 15 in the aperture and in order that the stud member can be rotated it is provided with a screw driver groove 35 and a hexagonal socket 36 to receive a hexagonal key. Specifications 414,290 and 485.837 [Group XXII] are referred to in the Provisional Specification.