Abstract:
A fastener (10) has a recessed drive configuration (18) with outlet channels (34,38,42) extending from the recessed drive configuration to the outer surface (50) of the fastener.
Abstract:
A fastener includes a round, blind hole or pocket in its head. Installation and removal of the fastener is accomplished with a tool containing an eccentric segment on the end of a shaft. When rotated within the pocket, the eccentric segment displaces laterally relative to the shaft to provide a friction grip to the lateral wall of the pocket. The strength of the grip is proportional to the applied torque. Eccentric displacement allows rotation but prevents the tool from spinning out of the fastener thereby eliminating cam-out and surface damage resulting from contact with a spinning tool tip. The eccentric head of the tool can be made disposable and to shear off when a predetermined torque is reached. The smooth-sided round hole offers no purchase for commonly available tools; making the fastener tamper-resistance. In another embodiment, the fastener includes a raised portion in the pocket. A tool having a complementary opening shears off the raised portion at a predetermined torque.
Abstract:
An anti-splay closure with a multi-surfaced aperture, such as a multi-lobular socket, includes a cylindrical body with an external, continuous, helically extending anti-splay guide and advancement flange and a breakaway installation head. The multi-lobular socket includes a plurality of circumferentiall-y spaced lobes extending parallel to a closure axis of the plug and which circumferentially alternate with spline receiving grooves extending parallel to the closure axis. The closure is used with an open headed bone implant screw having arms that are provided with internal, helically extending mating guide and advancement structures complementary to the body flange to allow slidable mating with the body upon rotation thereof and radial interlocking between the arms and the body.
Abstract:
Various screws (420, 720, 1020) and corresponding screwdrivers (404, 704, 1004) are disclosed. In one embodiment a screw (420, 720) has a single, circular, non-axial bore (424, 724) is disclosed. In another embodiment a screw has plural bores or other shaped bores (1024).
Abstract:
A fastener system comprising a plurality of ranges of size of threaded fastener (10), each fastener having a head (12, 32) provided with a recess (14) to receive a tool (20) to rotatingly drive the fastener. In each range of sizes, the largest size of fastener has a recess (14) comprising a plurality of driving tiers (16a, b, c, d) of reducing size superimposed on one another. Between two adjacent size ranges, there is a common tier (16d; 16b´), being the largest tier (16b', 16b'') of the recess (14', 14'') smaller size range, and the smallest tier (16d) of the recess (14) of the larger size range
Abstract:
A two-piece panel fastener includes a barrel-shaped metal retainer (10) which holds a screw. The screw includes a threaded shaft and a plastic cap (6) which has longitudinally-extending resilient fingers (7) which engage the outer surface of the retainer to captivate the screw. The retainer has a chamfered top flange (13) along its top edge, a circumferential bulge area (16) around its outer surface approximately in the middle of its length, and a base (15) at its bottom. Two circumferential valley regions of reduced diameter are located along the outer surface of the retainer. The first valley region is located between the chamfered top flange and the bulge area and the second is located between the bulge area and the base. When the fingers occupy either of the valley regions, the screw is captively held at either of two stable positions of retraction or extension. The retainer is preferably rigidly affixed to a circuit board (5) by soldering a base flange at the bottom of the retainer to the top surface of the board.
Abstract:
A combination of a screw with a screwdriver bit capable of effectively preventing the cam-out event of the screwdriver bit by improving the formation of a groove part in the cross groove of the screw so as to prevent the screw from being damaged and capable of remarkably increasing a working efficiency by always achieving an appropriate and rapid screw tightening operation even if the cross groove portion of the screw is damaged, and a header punch for manufacturing the screw, the header punch comprising the screw 30 having cutout step parts 36 of generally right triangle shape in cross section provided at the center parts of the tilted groove parts 32a of a bit fitted groove 32 formed in a cross groove at a screw head part 30a and a screwdriver bit 50 having projected parts 56 of generally triangle in cross section matching the cutout step parts formed at the center part of the tilted groove parts of the screw provided at the center part of the tilted end edge parts 52a of a flat-shaped blade part 52 and having the tip faces of the blade part 52 formed as conical projected parts 54.
Abstract:
A nut and bolt arrangement in which the nut is in two portions (10, 12) both of which have a threaded interior passage (14) of the same diameter for receiving a common bolt (18). The portion (10) has an annular formation (20) which has a greater diameter but smaller thread pitch than that of the passage (14). Portion (12) has at the same diameter, a matching external thread (13). When locked onto a bolt, this arrangement cannot be loosened without a special tool for engaging at (22).
Abstract:
The invention relates to a dowel (1) for lightweight building materials which comprises on its outer surface a self-cutting thread (3) and at its tip a cutting edge (2) with which it can be screwed into a gypsum plaster board. At the end opposite the tip the interior opening of the shank has a hexagonal cross-section (8), with a contiguous area (7) in which a screw can cut itself its thread. For screwing in the dowel the area (10) of the bit that is actually designed for engagement with the chuck of a driving tool is used as the hexagonal area somewhat projects from the chuck so that it can engage with the hexagonal recess (8) of the dowel sleeve.