Improvements in or relating to expansion wall-plugs

摘要

1,035,131. Wall-plugs. GLAREX A.G. Aug. 2, 1963 [Aug. 7, 1962], No. 30754/63. Heading F2H. The bore 3 of the unslit outer end 2 of a wall plug, which may be moulded from synthetic resin, tapers to a bore 4, shown as square-sectioned, which twists helically, through the slit inner end 1 together with the slits extending in tangential fashion from the bore 4. Two helical slits 5a, 5b are shown, but there may be three equally-spaced slits. The slit-helices can be right or left hand and have a pitch smaller than that shown, i.e. smaller than twice the length of the slit end 1 of the plug. The off-setting of the slits 5a, 5b from the plug axis, i.e. as shown in the view of the plug inner end 1a, Fig. 2, is in an anti-clockwise direction so that the driving- in of a right-hand screw causes the slits to tend to close but it can be in the opposite direction for a left-hand screw. The ends 5c, Fig. 4c, of the slits 5a, 5b, through annular ribs 1c diverge and open perpendicularly to a diametral plane of the slit end 1, irrespective of the direction of the slits, to facilitate extraction from the mould. Extended webs 6 and flush webs 7 are located between the annular ribs 1c. Tongues 8 at the outer end of the slit end 1 are pressed against flat portions of the plug outer end 2 to prevent turning of the plug when it is in position. Notches 10 in the edge of the mouth 2a facilitate squeezing of the mouth into the wall hole.