Gkn Screws & Fasteners Limited

Gkn Technology Limited

G.k.n. Fasteners Limited

Other

Richard Bergner Gmbh & Co.

Peter J Gill

Stewart C McRobert

Fastening member having threads, particularly a screw and screwing tool

Automatic clearance adjuster

An automatic tappet adjuster for a valve operating mechanism has two components 12, 14 with co-operating buttress thread form screw threads 32. The axial free play in the threads 32 sets the valve clearance. Excess clearance 56 is taken up by movement of one component, 14 acted on by a spring 40, relative to the other component 12. The buttress thread form 32 exhibits higher friction against rotation in one direction than in the other.

Threaded tappet adjuster

A combination of a cruciform recess in a fastener and cruciform driver has driver wings 13 which are narrower than corresponding recess radial grooves 21 and has downwardly tapered grooves and wings such that driving engagement between driver and fastener takes place at the outer upper edges of the recess. There is a relative downward taper between the wing width and groove width and these widths are so selected that the lower ends of the wings are confined by and preferably wedge in the recesses.

Fastener and driver combination

Method and apparatus for tightening a nut and bolt assembly to ensure that the bolt shank is tensioned correctly using a wrench having two relatively movable detector parts carried by the body of the wrench, one part being a cylindrical outer casing which engages the abutment surface non-rotatably, the other part being a stem extending axially from the body and having its outer end engaging the body of the nut and its inner end connected to a holder for a microswitch arranged to cooperate with an actuating member fixed to said outer casing, said microswitch being in an electrical circuit which controls power to the wrench and/or a visible or audible signal.

Load indicating nut wrench

A screw having a head and a threaded shank and, in the head, a cruciform shaped recess comprising a central cavity and four grooves radiating from the central cavity at 90.degree. angular spacings, the bases of the grooves lying on a conical (or pyramidal) surface and wherein the included angle at the vertex of such cone (or pyramid) has a value within the range 40.degree. - 45.degree., the preferred value being 40.degree..

Threaded fastener recess forming punch

A screw having a head and a threaded shank and, in the head, a cruciform shaped recess comprising a central cavity and four grooves radiating from the central cavity at 90.degree. angular spacings, the bases of the grooves lying on a conical (or pyramidal) surface and wherein the included angle at the vertex of such cone (or pyramid) has a value within the range of 40.degree. - 45.degree., the preferred value being 40.degree..

Threaded fastener

A self-drilling and self-tapping fastener, particularly suitable for use in relatively thick metal, which is made from a headed blank by a method including pressing into the cylindrical free end of the blank a pair of straight flutes, by dies which are closed together on a line which is acutely angled to both the leading and trailing walls of the flutes. The flutes are inclined in opposite directions relative to the screw axis and are positioned on opposite sides of the screw. The tip is machined off to a V-form, to provide a ridge angularly advanced about the axis of the screw relative to the cutting edges of the flutes. Further machining may remove metal from the sides of the drill point between the flutes to provide flats and the drill point may be turned to a circular cross-section to provide sharp well-supported cutting edges for improved wear resistance. The drill point may taper overall, being of smallest diameter adjacent the threaded fastener shank.

Growing community of inventors

Wolverhampton, United Kingdom

Peter J Gill