Abstract:
The invention relates to a handtool and screwed fasteners. The invention ensures the long service life of screw drives and wood screws and the processabilty thereof. The screw consist of a head and a working end with a screw thread. The slot in the head for the screw drive is dovetail-shaped. The working end of the screw drive for screwing in and off the screw is made in the form of the mirror reflection of the slot of the screw head and with the same tilt angle.
Abstract:
A thread forming fastener for threading into a nut anchor of a pliable material wherein there is produced during the driving of the fastener a combination of forces that encourages the nut anchor material to flow smoothly and to develop a mating thread in the nut anchor that minimizes stress cracking and radial hoop stress as the mating thread is being formed. The fastener comprises a drive head and a shank extending from the head and having a longitudinal axis, the shank including a core and a thread having a selected axial pitch, a selected thread height and a profile which in axial cross-section includes a leading face, a trailing face and a tip. The leading face is composed of a radially inner concave portion having a first radius and which transitions smoothly to a radially outer convex portion having a second radius, the transition occurring at a point on the common tangent to those portions. The trailing face is composed of a radially inner linear portion which transitions at a selected transition location to a radially outer convex portion having a third radius. The profile also includes a convex blending portion having a fourth radius which blends together the radially outer leading and trailing face portions at the tip. The thread profile produces force vectors during assembly with the nut anchor that provide enhanced mating thread strength and improved resistance to nut anchor thread breakdown.
Abstract:
Eine für hartes Holz geeignete Schraube enthält eine Schraubenspitze (3) mit zwei angenähert parallel zueinander verlaufenden quer zur Schraubenlängsachse orientierten Schneidkanten (5). Der Schneidwinkel der Schneidkanten beträgt etwa 90°. In Verlängerung der Schraubenlängsachse ist eine Zentrierspitze (7) ausgebildet, die etwas über die beiden Schneidkanten (5) vorspringt. Diese Zentrierspitze (7) verhindert das seitliche Ausweichen der Schraube zu Beginn des Bohrvorgangs.
Abstract:
Die Erfindung betrifft ein Schraubenelement (1), insbesondere zur Querzug- und/oder Querdruckverstärkung von Holzbauteilen durch Einsetzen in ein vorgebohrtes Kernloch. Das Schraubenelement (1) besteht aus einem Gewindeschaft (2) mit einem durchgehenden Gewinde (4) und einem einendigen Kraftangriff (6) zur Drehmoment-Beaufschlagung. Der Gewindeschaft (2) ist von einem Gewindestangen-Abschnift (8) mit einer Länge (L) von mindestens 600 mm gebildet. Hierbei ist das Gewinde (4) als spanlos gewalztes, selbstgewindeformendes Holzschraubengewinde in Form einer schraubenlinienförmig über einen zylindrischen Schaftkern (10) verlaufenden, von zwei in einer äußeren Gewindekante (16) zusammenlaufenden Flanken (12) begrenzten Erhebung (14) ausgebildet. Der Kraftangriff (6) ist von einem ursprünglich separaten, an ein Ende des Gewindestangen-Abschnittes (8) angeschweißten Angriffsteil (18) oder einem durch Anstauchen angeformten einstückigen Angriffsteil (18) gebildet.
Abstract:
A threaded fastener, such as a screw, includes a head and a shank extending from the head and having a tapered tip portion. The head may have an annular recess open on the side of the head adjacent the shank. A pair of lands are disposed between a pair of flutes circumferentially surrounding the tip portion. A first threaded portion extends about the shank along at least a portion of the tip portion. A second threaded portion extends about a portion of the shank between the head and the first threaded portion. The thread of the second threaded portion may turn at a slower rate than the thread of the first threaded portion. The head may be a conventional flat head having an internal drive recess. The tip portion may include a type seventeen screw point.
Abstract:
Ein Pfostenanker (1) besteht aus zwei endseitigen Abschnitten (11, 12), wobei der eine Abschnitt (11) in einen Pfosten (10) einbringbar ist und der andere Abschnitt (12) zur Befestigung an oder in einem anderen Element vorgesehen ist. Dabei ist der in den Pfosten einbringbare Abschnitt (11) ein Bohrerabschnitt (11) zur im wesentlichen spannungsfreien Einbringung eines Bohrloches (20) in den Pfosten (10). Der Bohrerabschnitt (11) in dem Bohrloch (20) weist im wesentlichen kein axiales Spiel auf und ist vorzugsweise ein Schlangenbohrer.
Abstract:
The invention concerns a wood-screw characterised in that it comprises two identical threads (5) and (6) longitudinally offset. Each of them consisting of two unsymmetrical flanks, one in front (9) along a first slope and the other at the rear (10) along a steeper slope. The threads start the furthest possible towards the front of the tip (4).
Abstract:
A fastener having a shank portion (11), at least part of the shank portion being provided with a screw thread (14), an head portion (12) at one end of the shank portion and a tip portion (13) at the other end of the shank portion wherein the screw thread does not extend to the tip portion. The tip portion is substantially symmetrical about the axis of the shank portion, and may be pointed and/or conical, with a generally smooth outer surface. The head portion has a recess therein, such as a single elongate slot or a cruciform formation (26), to enable the fastener to be rotated by an appropriate tool. Since the screw thread does not extend to the tip portion, the fastener may be inserted into a material by hammering, while the form of the thread prevents removal of the fastener from the material other than by application of rotational movement. The fastener may thus be inserted into a material rapidly, without the necessity of imparting rotational movement to the fastener.
Abstract:
A wood screw is characterised in that its core (2) is generally cylindrical with a diameter which does not exceed that of a prebored hole, that it comprises two threads, viz. a main thread (3) and an auxiliary thread (4), of which the former protrudes considerably more from the circumference of the core than the latter and both of which are formed as sharp threads, i.e. are thin in relation to their depth, and that the front end of the cylindrical core is provided with a recess (5) having an edge (8) acting as a cutter.
Abstract:
A screw (10), extending in an axial direction (A), for engagement with wood or similar composite material, by rotating said screw in a rotational direction (W) around a rotational axis (AC), comprising: a shank (14) having a threaded region (15); a countersunk head portion (12) having a top side (19) with a driving-tool receiving recess (43), and an essentially frusto-conical lower portion (18), comprising a cutting recess section (20) having a trailing region (22), as seen in the rotational direction (W), comprising a cutting edge (23) with a first axial end point (41 ) and a second axial end point (42), defining an imaginary straight line (Al), which defines a positive cutting edge angle (a) relative to a plane (AP) extending in a radial direction (R), from said rotational axis (AC) to said first axial end point (41 ), and in said axial direction (A); wherein the extension of the maximum depth of a cutting recess section (20) in the radial direction (R) is essentially aligned with the innermost point (46) of the driving-tool receiving recess (43).