Abstract: A screw-type fastening device including a male threaded element such as a bolt and a female threaded element such as a nut in which each element contains a continuous helical root and crest disposed therein wherein the root and crest include V-shaped crests and V-shaped roots at an angle of 45.degree., respectively, external and internal chevron-shaped slots at angles of 90.degree., respectively, and three pairs of parallel load flanks, respectively, for easily releasing the threaded elements without abrasion and protecting them from self-lossensing from each other.

Abstract: A nut is provided particularly for use with a sheet metal screw, which nut has a screw-receiving sleeve, with two or more roll-tapped threads having a flattened crest at the apex of the thread angles. An alternate embodiment contemplates providing a double thread on the sleeve inner surface of at least two full revolutions.

Abstract: A quick-action fastener for connecting two plates (III) and (IV) with a resilient gasket (V) interposed therebetween, all three being perforated by a throughgoing hole, comprises a bolt (I) passing through this hole and engaging with a bore (24) in a socket (II) which is rigidly fastened to the plate (III). A helical groove (14) is cut into the end of the bolt, which has a lead angle not exceeding 15.degree., and which engages with a protrusion (42) inwardly projecting from the bore (24) of the socket. Friction between the protrusion (42) and the wall of the helical groove (14) is strong enough to hold the bolt in position and to clamp the two plates together, owing to the tension of the resilient gasket.

Abstract: A locknut having a single-turn thread for securing electrical fittings, threaded conduit and the like to electrical junction boxes and the like is disclosed. The locknut comprises a generally cylindrical portion, a flange portion attached to the cylindrical portion, a plurality of teeth attached to and projecting radially outwardly of the flange portion and axially beyond the end of the flange portion, and a standard thread attached to and extending for substantially only a single turn interiorly of the cylindrical portion. The thread has an included angle corresponding to that of a standard thread, for example, 60.degree.. The teeth seat against a work surface when the locknut is threaded onto the fitting and act as springs which can compensate for a small degree of element loosening by spring recovery. In addition, the thread of the locknut is flexible so that both the teeth and thread act as springs working in conjunction with each other.

Abstract: A threaded member made of fiber-reinforced plastic (FRP) obtained by the present invention which is characterized by having at least the threaded portion coated with a crosslinked nylon resin. Accordingly, the surface of the threaded portion is smooth, exhibiting adequate elasticity and fitness, and exhibiting excellent screwing ability to enable the smooth meshing of a nut with a bolt without jolting. Moreover, the threaded member is also excellent in weathering resistance and chemical resistance.

Abstract: According to a depicted embodiment thereof, the novel threaded engagement means comprises a drill rod coupling which is centrally bored and threaded to receive threaded drill rods. A stack of apertured discs, however, engages and lines the threaded bore. The discs intimately engage, and bridge between, the coupling and drill rod threads, and communicate torque therebetween. The coupling has a bearing surface or land upon which the discs are supported, and a retainer set in a recess formed in the coupling secures the disc stack in place.

Abstract: A base member of a ski binding has vertical bores therethrough, and fastening screws which extend through the bores secure the ski binding to the top surface of a ski. Each bore has two vertically spaced, inwardly projecting shoulders which extend generally parallel to the top surface of the ski. Viewed from the top, each shoulder is delimited by two circles of different radius, the larger radius being equal to the radius of the bore. The two circles intersect tangentially at a point opposite the center of the shoulder, and the contact points of the circles of the respective shoulders are angularly offset by 180.degree. with respect to each other.

Abstract: Ball nuts are preloaded onto a ball screw by rotating the nuts relative to one another to jam adjacent end faces of the nuts together. Thereafter, the nuts are held against relative rotation by tightening a clamping ring secured to one of the nuts and adapted to frictionally engage the other nut to prevent rotation thereof.

Abstract: An orthodontic screw-type biassing device comprises: a first member having an internally threaded bore, the threaded bore comprising first and second threaded portions adjacent each other in the axial direction of the bore, the first and second threaded portions having thread roots which lie substantially on a common line, the first threaded portion having threads of given depth and the second threaded portion having threads of a lesser depth. A threaded inner screw-type member is threadably engaged in the internally threaded bore of the member, the threads at an end portion of the inner screw member being deformed so as to freely, threadably pass through the second threaded portion of the threaded bore and to bind and be non-rotatable in the first threaded portion of said threaded bore. The invention is also directed to a method of making such a biassing device.

Abstract: A tri-lobular, all metal, prevailing torque nut is disclosed providing a cone having three locking sections, each of which extends around the threaded opening for about one-third of the surface of its thread. Each locking section provides a minimum radial distance at its center and extends with gradually increasing radial distance to the ends thereof. When the nut is threaded onto a mating threaded fastener, portions of each locking section are radially displaced from their unstressed condition to the circular shape of the mating fastener, producing frictional engagement between the nut and the fastener to resist unintentional loosening. Each locking section is arranged so that it provides a maximum resistance to deflection at its center and decreasing resistance to deflection at locations progressively spaced from the center so that excessive pressures are not developed which would tend to produce excessive wear or permanent deformation.

Abstract: A threaded insert and method for making same which is particularly usable when fixedly positioned within a base material which itself is molded about the threaded insert, the threaded insert comprising a generally cylindrical body which is preferably knurled about the exterior thereof to provide a means for fixed securement between the insert and the surrounding base material, the cylindrical body including a central bore extending part way or completely through the insert, the central bore being threaded such that each individual thread includes a burnished end thereof such as to provide an arcuate surface immediately adjacent the mold or immediately adjacent the pin extending through the central bore to prevent the seepage of base material when under pressure during molding past the threads to foul the threads by having base material therein, the dimension of the burnishing on the tips of the threads being of such small dimension that the first placement of a threaded male member into the threaded central b