Abstract:
A screw (10) comprising a tip (11); a head (12) for accommodating a tool to rotate the screw (10) around a rotational axis (17) of the screw (10); and a thread (15) extending from the tip (11) towards the head (12), the thread (15) having a thread depth (w) that varies along a length of the screw (10) between a minimum thread depth and a maximum thread depth (w max ), wherein the thread (15) comprises a tip thread portion (18) extending along one half turn or less around the rotational axis (17) of the screw (10) and exhibiting a thread depth increase (Δw 1 ) within the tip thread portion (18) corresponding to at least one half of the maximum thread depth (w max ). Hereby a reduced axial force is needed for starting the entry into a workpiece of the screw.
Abstract:
There is disclosed a method of forming a floating connection between a structural member and a wall member, the method comprising securing a rigid connecting element to one of the members such that it projects from that member, along a substantially upright axis, into the other member, whereby there is formed, between the element and said other member, a sliding fit which permits relative movement between the element and said other member parallel to the axis but precludes relative movement between said element and said other member perpendicular to said axis, thereby allowing the structural member to move parallel to the axis but transferring, from the wall member into the structural member or from the structural member into the wall member, loads perpendicular to the axis so as to brace the member from which it transfers the loads.
Abstract:
The invention relates to a screw and method for the mounting of boards/planks, in particular fiber cement planks, on a support of wood. The screw comprises milling wings and a first thread between the milling wings and the tip, and a second, larger thread with smaller pitch between the milling wings and the screw head.
Abstract:
A fastener includes a shank (100) having a pilot section (110) and a threaded section (113). The pilot section includes a cutting tip (111) and a drill section (112); the threaded section includes a first thread region (113) having the same twist as the drill section and a reverse thread region (114). A helical ridge (115) may be provided in the reverse thread region. A head (104) at the second end includes a top portion such as a disk and an undercut region.
Abstract:
A fastener includes a shank having a point at a first end and a second, head end. A first helical thread region is formed at the first end adjacent to the point having a first helical thread having a first effective diameter. A sub-region of a second helical thread is formed within the first helical thread region adjacent to the first end. A head at the second end includes a cutting structure, the cutting structure positioned to intersect a bottom surface of the disk and the shank, the cutting structure has a square cross-section formed by four walls intersecting the disk. A third helical thread region may be provided between the first region and the head. The shank diameter in the sub-region and the first region is smaller than the other regions.
Abstract:
A screw for composite or plastic material comprises a head having a socket which is rotatably couplable for application of a torque. An elongated shank extends from the head and terminates a tapered threaded distal tip. The shank has one portion having an enlarged diameter and a second portion having a reduced diameter. The first portion is traversed by a left hand thread having a first pitch. The second portion is traversed by a right hand thread having a second pitch which is less than the first pitch. An unthreaded land portion adjacent the tip extends at least twice the second pitch. For some embodiments, some thread segments have notches. The fastener is particularly adapted for very dense material.
Abstract:
A method for fastening an object in a fiber-reinforced composite material (21), comprising the steps of arranging a hole (22) in the material (21) for receiving a device (10) having a body (11), an external thread (12) extending from said body (11) and an axial bore (14) with an internal thread (15), wherein the diameter of the hole (22) is arranged larger than the diameter of the body (11) to form a gap (23) between the material (21) in the hole (22) and the body (11) when the device (10) is inserted in the hole (22), applying an adhesive (26) on the external thread (12) of the device (10) and/or on the material (21) in the hole (22), screwing the device (10) into the hole (22), so that the external thread (12) of the device (10) engages the material (21) and the adhesive (26) fills the gap (23) between the material (21) in the hole (22) and the body (11), screwing a screw having an external thread into the bore (14), so that the external thread of the screw engages the internal thread (15) of the device (10) to fasten the screw, and engaging the screw with the object to be fastened to fasten the object to the material (21). The invention is also related to a device for fastening an object in a fiber- reinforced composite material.
Abstract:
A screw fastener (1) having a head (H), threaded shank (S) with compound, divided threads (T) and tip end (P) has an upper thread surface extending at a substantially flat angle from a normal to a longitudinal axis (3) of the screw which diverts upwardly to a first peripheral edge defining a cupped or concave upper thread surface and a lower thread surface extending upwardly to a second peripheral edge, with a radially inward recess between first and second edges. The screw exhibits significantly increased pull-out resistance.
Abstract:
A torque retention screw thread fastener and corresponding thread roll die to manufacture the screw thread fastener is disclosed. The torque retention thread forming screw comprises retention elements in the thread valley of the screw thread which reduces retro-grade rotation due to vibration loosening, and contributes to a reliable joint, to provide superior clamp load in the joint when the screw thread fastener is fully tightened and reduces the possibility of stripped assemblies.