Abstract: The invention relates to a screw (1), having a shank (3) which is provided with a thread (2) with at least one asymmetrical thread turn (4) with a plurality of windings, wherein the thread has an external diameter (Da), a core diameter (Dk) and a thread pitch (P), wherein the thread turn (4) has thread flanks (7, 8) with a flank angle (phi), wherein the thread flanks (7, 8) have a load-bearing flank (7) and a counter-flank (8) which abut one another directly or indirectly in a thread bottom (9) and at a thread tip (10), and wherein a flank angle (phiL) of the load-bearing flank (7) is smaller than a flank angle (phiG) of the counter-flank (8). The flank angle (phiL) of the load-bearing flank is at least 25°, preferably from 25° to 35°, in particular 30°, and the flank angle (phiG) of the counter-flank is at least 40°, preferably from 40° to 60°, in particular 50°, wherein the flank angle (phi) is from at least 65° to at most 95°.

Abstract: A threaded fastener includes an elongated body having a first end and a second end, a first portion comprising a first helical thread, with the first helical thread including a crest, a root, and flank portions, and a second, tapered portion including a second helical thread. The second helical thread includes a crest, a root, a leading flank portion, and trailing flank portion, with the leading flank portion positioned closer to the second end of the elongated body than the trailing flank portion. A thread angle of the second helical thread is larger than a thread angle of the first helical thread, and the root of the second helical thread includes a root apex formed by the intersection of the trailing flank portion and the leading flank portion.

Abstract: The present invention discloses a dental implant (30; 130; 230; 330; 430) for preserving soft tissue and promoting bone growth, including an elongated implant body having a coronal end portion (31; 131; 431) and an apical end portion (32; 132; 332; 432); an external thread (40; 140; 240; 440); a flute arrangement (50; 150; 350; 450) having at least one helical flute having a depth; in which the apical end portion forms a blunt tip (39; 139; 339), and in which the helical flute spirals in opposite direction to the external thread, and the flute exits on the face of the blunt tip.

Abstract: An osteo-implant is provided, having a fixing segment and an implant end. The fixing segment is provided with a thread and at least one bone healing chamber. The bone healing chamber is located at a thread root of the thread. The bone healing chamber is a chamber inwardly depressed from a surface of the fixing segment. The fixing segment has a central axis. In the same section of the fixing segment, an area of a section, which is parallel to and passes through the central axis, of the at least one bone healing chamber closer to the implant end is smaller.

Abstract: A device for ensuring proper installation of a helical insert is provided. The device includes a head portion, a body portion, and at least one thread-forming member. The body portion has a first section and a second section, and the first section of the body portion depends from the head portion. The second section of the body portion is longer than the length of the helical insert. The at least one thread-forming member is located on the first section of the body portion such that a radial extent defined by the at least one thread-forming member is greater than a radial measure to the inner diametrical surface of the helical insert. A method of using the device is also provided.

Abstract: A mounting screw (1), comprising a head part (2), a tip part (3), the tip part (3) having a tapered shape tapering from the shank part (4) to the tip (5) of the screw, and comprising a tip part thread (6), said tip part thread (6) extending to the very end of the tip (5). The mounting screw (1) further comprises a shank part (4) between the head part (2) and the tip part (3), the shank part (4) comprising a shank part thread (7), wherein the pitch (P1) of the shank part thread (7) is larger than the pitch (P2) of the tip part thread (6), and the thread root of the tip part (3) being frustoconical in its shape.

Abstract: A fastener includes a shank, a head connected thereto, a drilling portion opposite to the head and a plurality of first threads and second threads spirally disposed on the shank. The second threads are affixed to the first threads and provided with a plurality of opening slots defined thereon. The opening slots expose portions of the first threads therethrough. The first threads divide the shank into a plurality of shank segments, each of which has a base part and a transition part extending outward from the base part to be inclined by 5 to 10 degrees. The opening slots formed on the second threads provide an auxiliary cutting effect and accommodate cut debris. The first threads reinforce the bearing and drilling force of the second threads. The inclined transition part helps increase the ability of resisting the driving torsion and attain an anti-loosening force, thereby increasing the fastening effect.

Abstract: A self-tapping screw having a head and an outer thread carrier with an end at which the outer thread has an outer diameter decreasing towards the end, at least over a part of the length thereof ending at the end, and the outer diameter of the outer thread decreases according to the draft angle of holes in which the screw is to be set.

Abstract: A connecting member for two parts includes a first half (2) and a second half (3) meeting at a center (M) of the connecting member (1). The first half (2) includes a first number of ramp portions (41-45) widening toward center (M) in an axial direction (X) thereof. The second half (3) includes a second number of ramp portions (51-55) widening toward center (M) in an axial direction (X) thereof so that the first half (2) and the second half (3) have opposite toothing.

Abstract: A thread forming screw thread fastener and a corresponding thread roll die are disclosed for fastening into a hole of a workpiece composed of low ductility material. More specifically, the thread forming screw thread has smooth radius thread flank which has a capability of deforming low ductile material such as magnesium, soft aluminum, thermoset plastics and other low ductility materials to deform the ductile material efficiently minimizing cracks, debris, low friction during installation and a maximum engagement of the screw with mating parts with the ductile material.

Abstract: An improved threaded connection, in which a first part having a female thread is threadably engageable with a second part having a male thread. The first and second parts have different strengths in at least the area of the thread turns, and the thread turns have cross-sectional areas that differs from the cross-sectional areas of gaps between the thread turns.

Abstract: A thread forming screw thread fastener and a corresponding thread roll die are disclosed for fastening into a hole of a workpiece composed of low ductility material. More specifically, the thread forming screw thread has smooth radius thread flank which has a capability of deforming low ductile material such as magnesium, soft aluminum, thermoset plastics and other low ductility materials to deform the ductile material efficiently minimizing cracks, debris, low friction during installation and a maximum engagement of the screw with mating parts with the ductile material.

Abstract: A fastener with multiple thread characteristics includes a shank and head. The shank has a penetrating tip distal most from the head. The shank includes a first, conventional thread formation formed therein adjacent the penetrating tip and a second, anti-back-out thread formation adjacent the conventional thread formation, between the conventional thread formation and the head.

Abstract: This invention is directed towards a paint spray gun having a gun body with a male thread and having an air nozzle ring with a female thread which can be screwed onto the male thread of the gun body. The diameter of the thread is between about 30 and about 40 mm. The thread of the invention is a trapezoid thread with a flank angle in the range of about +/?20% of 30°. The thread has a thread height within the range of about +/?20% of 1.1 mm, a root to crest clearance within the range of about +/?20% of 0.1 mm and a flank clearance within the range of about +/?20% of 0.15 mm. The effect of these modifications to a standard trapezoid thread with a flank angle of about 30° is that the thread is optimally adjusted to serve as a thread connecting the body of a paint spray gun and a nozzle ring.

Abstract: The present invention is directed to a deck screw intended for use with composite lumber, although it can be used with other wood products, such as pressure treated lumber. The deck screw of the present invention may be provided with a head and a shaft that has two regions of varying diameter. The upper region has threads that exceed the number of threads of the lower shaft, on a unit length basis. The threads of the upper shaft may be configured in an inverted buttress design. The lower region of the shaft terminates at a tapered distal end having a pointed tip that leads the screw through the wood material. Threads are provided on the lower region of the shaft. The head of the screw is provided with an upper surface, a lower surface, and a crown that extends around the perimeter of the head, The crown extends beyond the lower surface of the head, forming a recessed region between the lower edge of the crown and the shaft of the screw. The head may also be provided with an undercut.

Abstract: A self-drilling fastener for attaching wood substrates to metal substrates comprises an elongate shank defining an axis, the shank having a first end and a second end. A drilling tip having a drill point and an axial length is formed at the first end. A broad head is formed at the second end. The shank includes a threaded portion and an unthreaded portion. The threaded portion axially extends from the drilling tip towards the head and includes helical threads and has an axial length, a root diameter, and a thread diameter. The length of the threaded portion is greater than the length of the drilling tip. The unthreaded portion axially extends from the threaded portion to the head and has an axial length and a diameter. The length of the unthreaded portion is substantially greater than the length of the threaded portion and the diameter of the unthreaded portion is smaller than the thread diameter of the threaded portion.

Abstract: A thread coupling for a drill string for percussive drilling has a male thread (5) and a cooperating female thread (4). The male thread is arranged on a first drill string element (3) having a first impact surface (6). The female thread is arranged on a second drill string element (2) having a second impact surface (7). The male and female threads are conical, and the crests (8) of the male thread (5) have a radius of curvature more than thirty degrees of the pitch of the thread.

Abstract: A thread forming screw configured for insertion into relatively hard plastics includes an elongated core region having two ends, a head at one end and a point at the opposite end, a helical thread extending generally radially from the core region, the thread being asymmetrical when viewed in a cross-section taken through a diameter of the core, the thread defining a flank angle made up of a leading angle, facing the point, and a trailing angle facing the head, the leading angle being greater than the trailing angle.

Abstract: The present invention is directed to provide a tapping screw for a soft material having a sufficiently large stripping torque compared to a driving torque and an increased tolerance of a fastening torque, and characterized in that it has threads each having a leading flank and a following flank, the leading flank being designed to be steeper than the following flank, that an R is imparted to a crest of each thread on the following flank side, that an R is also imparted to each flank at a portion contiguous to a root thereof and that the former R and the latter R being designed to connect smoothly to each other at the root.

Abstract: An oil-country-tubular threaded joint can withstand tensile forces, and in addition, other forces such as compression and bending forces, thus producing highly improved characteristics in regard to the prevention of fluid leakage. The oil-country-tubular threaded joint is formed of male screw threads and female screw threads which have a load face whose load flank angles are in a range of −3° to −25°, in which the load flank angles are varied at a position at which the load face is divided in the height direction of the male screw thread into an upper side and a lower side so that an upper load flank angle is smaller than a lower load flank angle by 0.5° to 2.0°. Also, a thread-machining apparatus for the oil-country-tubular threaded joint uses chasers having cutting edges which are shaped so as to correspond to thread shapes for machining screw threads whose flank angles are partly of negative values for the oil-country-tubular threaded joint.

Abstract: A thread forming screw configured for insertion into relatively hard plastics includes an elongated core region having two ends, a head at one end and a point at the opposite end, a helical thread extending generally radially from the core region, the thread being asymmetrical when viewed in a cross-section taken through a diameter of the core, the thread defining a flank angle made up of a leading angle, facing the point, and a trailing angle facing the head, the leading angle being greater than the trailing angle.

Abstract: An enhanced strength screw-type, self-tapping masonry anchor bolt for fastening a fixture or other attachment to masonry in which a hole is drilled to receive the anchor. The anchor is provided with a shank having a root section surrounded by at least one helical male cutting thread whose crest diameter exceeds the diameter of the hole whereby when the anchor is screwed into the hole, the cutting thread then cuts a female thread in the bank of the hole to mechanically retain the anchor therein to impart to the anchor a holding power that resists axial pull-out forces. The cutting thread has a leading face that is arcuate or radial (circular) and a trailing edge that is flat and disposed essentially normal to the shank of the bolt. Also provided is a masonry anchor for use with thin-walled masonry articles such as cinder blocks which is essentially a sleeve of a durable polymeric material.

Abstract: A threaded fastener having a shaft with a screw thread disposed thereabout, a pressure flank of the screw thread having a first pressure flank angle on a radial inner portion thereof and a second pressure flank angle on a radial outer portion thereof, the first pressure flank angle less than the second pressure flank angle. The fastener is preferably embodied as a screw fastener with a relatively small gimlet angle.

Abstract: A suture anchor for facilitating the anchoring of soft tissue to a bony site includes a distal sharpened tip, and intermediate threaded section and a proximal drive head. The drive head is configured to receive a socket drive tool and has a suture-receiving eyelet formed therethrough. The threaded section is defined by a crest taper angle that is greater than the root taper angle.

Abstract: A screw threaded fastener (103) has an elongate shank (122) with a drilling tip (104) at one end and a head (123) at the other end. A screw thread extends along at least a part of the length of the shank (122). The trailing flank (116) of the thread subtends an angle (B) relative to the axis (117) of the fastener which approaches 90° and is greater than the angle (C) subtended by the leading flank (115). The screw is for use in fixing sheets of material a1 to thin metal battens (5) and the angle between the trailing flank (116) and the adjacent thin metal section (18) of the batten (9), being reduced in comparison to a conventional thread form, lessens the distorting effect of the thread on the batten (9) under relatively high pull-out loads.

Abstract: An improved fastener comprising a head portion, a flange portion, a shank portion which extends through two aligned apertures formed in adjacent panels and a collar swaged on the shank portion. The shank portion includes a gripping portion having a plurality of gripping surfaces formed between a plurality of cone shaped grooves, the configuration of the gripping portion being spiral shaped. The collar is installed by first positioning it over the fastener shank portion, an installation tool then swaging the collar thereto, the collar being tightly held by the multiple gripping surfaces to prevent movement in the direction of the longitudinal axis of the fastener. A mating spiral shaped configuration is formed along the interior surface of the collar during the swaging process.

Abstract: An enhanced strength screw-type, self-tapping masonry anchor for fastening a fixture or other attachment to masonry in which a hole is drilled to receive the anchor. The anchor is provided with a shank having a root section surrounded by at least one helical male cutting thread whose crest diameter exceeds the diameter of the hole whereby when the anchor is screwed into the hole, the cutting thread then cuts a female thread in the bank of the hole to mechanically retain the anchor therein to impart to the anchor a holding power that resists axial pull-out forces. Formed on the root in the helical land between successive convolutions of the thread is a ridge that is raised above the root to define a compacting zone between the ridge and the bank of the hole. Particulate debris produced by the cutting action is discharged into the land and forced into the compacting zone to create a dense mass that wedges the anchor in the hole and thereby enhances the holding power of the anchor.

Abstract: An orthopedic interference screw for compression anchoring a bone graft in a bore formed in a bone mass. The interference screw includes a biocompatible body with a root. A screw thread is formed over substantially all of the root. The screw thread includes buttress structure on only one side of the screw thread so that forces applied to the screw thread from a side remote from the buttress structure will be buttressed by the buttress structure.

Abstract: A self-drilling fastener includes an elongated shank region having first and second ends, a head at the first end and a drill point at the second end. Included in the shank region is a root having helical threads extending therefrom with a predetermined thread density. The threads are configured to extend onto the drill point, which point extends from the root, and has a conical point with a rounded tip and a flat side. The flat side defines a pair of drilling edges.

Abstract: An orthopedic interference screw for compression anchoring a bone graft in a bore formed in a bone mass. The interference screw includes a biocompatible body with a root. A screw thread is formed over substantially all of the root. The screw thread includes buttress structure on only one side of the screw thread so that forces applied to the screw thread from a side remote from the buttress structure will be buttressed by the buttress structure.

Abstract: A bushing adapted to be secured within a circular aperture of a structural channel support member has a head, and a shank portion having an external male machine thread. A centered bore having an internal machine thread penetrates the head and shank portion. The head has a flat inside shoulder adapted to abut against the channel member.

Abstract: A tool having a profile for the forming or shaping of a complementary thread in and/or on a fastener which can be utilized with advantage as a bone screw or another osteosynthetic force transmitting member, instrument or accessory. The thread which is formed by the profile of the tool has two flanks each having a first section adjacent the crest and a second section adjacent the root of the thread. The second sections jointly include or consist of at least four concave portions having different radii of curvature and gradually merging into each other. The first sections make angles of less than 40.degree. with a plane which is normal to the longitudinal axis of the thread. The first and second sections of each flank are separated from each other by an imaginary cylinder having a diameter which matches the pitch diameter of the thread and a longitudinal axis which coincides with or is at least close to the longitudinal axis of the thread.

Abstract: A fastener system capable of clamping a workpiece that provides for enhanced distribution of the internal forces that are generated in the components as a result of the assembly of the system. The fastener system includes an externally threaded member having a thread formed thereon with a substantially non-triangular profile, and an internally threaded member having a thread formed therein which also includes a substantially non-triangular profile. In assembled form, the substantially non-triangular thread faces of the internally and externally threaded members mate along a contact face and, by virtue of their unique thread forms, are able to withstand axial loads of greater magnitude than comparable systems employing threads having substantially triangular profiles.

Abstract: A threaded screw has a first segment adjacent the screw head (10) with nontapered sides for engaging metal automotive fastener clip nuts (30) and a second segment with tapered sides for engaging plastic bosses (24). The second segment is adjacent the first segment but distant from the screw head (10). A single set of threads (36) is used for both the metal clip nut (30) and the plastic boss (24). The threads (36) have a helical pitch angle (P) of about nine degrees and form a flank angle (.beta.) of about thirty degrees relative to a horizontal axis (20) of the screw. The screw taper matches the taper of the boss opening (22) to promote even stress distribution.

Abstract: An improved fastener comprising a head portion, a flange portion, a shank portion which extends through two aligned apertures formed in adjacent panels and a collar swaged on the shank portion. The shank portion includes a gripping portion having a plurality of gripping surfaces formed between a plurality of cone shaped grooves, the configuration of the gripping portion being spiral shaped. The collar is installed by first positioning it over the fastener shank portion, an installation tool then swaging the collar thereto, the collar being tightly held by the multiple gripping surfaces to prevent movement in the direction of the longitudinal axis of the fastener. A mating spiral shaped configuration is formed along the interior surface of the collar during the swaging process.

Abstract: A fastener is a screw having a threaded shaft, and a fastening strip or sheet having a raised portion provided with an aperture being preformed to have an at least partly helical threadform-defining edge shaped and dimensional to matingly receive the threaded shaft of the screw. The crests of the threaded shaft have an asymmetrical surface profile in the axial direction of the threaded shaft which enables the shaft to withstand greater applied torque.

Abstract: A fastener which can be utilized with advantage as a bone screw or another osteosynthetic force transmitting member, instrument or accessory has a thread with two flanks each having a first section adjacent the crest and a second section adjacent the root of the thread. The second sections jointly include or consist of at least four concave portions having different radii of curvature and gradually merging into each other. The first sections make angles of at least 40.degree. with a plane which is normal to the longitudinal axis of the thread. The first and second sections of each tooth flank are separated from each other by an imaginary cylinder having a diameter which matches the pitch diameter of the thread and a longitudinal axis which coincides with or is at least close to the longitudinal axis of the thread.

Abstract: A masonry fixing device 1 comprises a steel shank 2 which in the form of the blank is right circular cylindrical form. A ridge-groove-ridge configuration extends helically along the lower portion 4 of shank 2 and comprises a pair of parallel opposed ridges 7 upstanding from an adjacent land 9. Each ridge defines with the adjacent ridge a groove 5. At least the forward end of the lower portion 4 of shank 2 is configured so as to provide a self-tapping facility. In use, the fixing device is introduced into a pre-drilled bore in a masonry substrate such as brickwork by turning so as to form a thread on the interior walls of the bore. The axial dimension of the land 9 is at least 50% of the blank diameter with the result that relatively large amounts of substrate material are disposed between the ridge-groove-ridge configuration when the fixing device is in place.

Abstract: An anchoring arrangement for use in underground mining or foundation work or as a reinforcing element for concrete includes a rod-shaped tension member of composite fiber material which has, over at least an anchoring portion thereof, a helically extending external thread with ribs formed by impressing valleys in the tension member. An anchoring member having a corresponding internal thread can be screwed onto the tension member. For obtaining a radial pressure on the tension member as a result of a wedge effect, the angle of inclination of the sides of the thread relative to the longitudinal axis of the tension member is smaller than 45.degree.. The thread preferably is a fiat trapezoidal thread. In an anchoring member which is stiff relative to circumferential tensile forces, the flat angle of inclination of the sides of the thread increases the radial pressure acting on the tension member, which leads to an increased effect into the depth and a higher resistance to shearing.

Abstract: A fastener for fastening a pair of metal panels comprises a head which has an annular recess at its underside. A threaded shank has a buttress thread which terminates in a self-driving tip. An sealant/adhesive coating is preapplied to the fastener. The coating seals and bonds between the fastener and the panels upon installation of the fastener.

Abstract: Disclosed is a stud bolt having nonsymmetrical screw threads projecting from the shank thereof, wherein each screw thread of the stud bolt has an inwardly concave curved flank and an outwardly convex curved flank. With this arrangement, the load required to fit a resin clip over the stud bolt can be lowered below that needed for a conventional stud bolt while maintaining the load required to remove the clip equal to or more than that for the conventional bolt. Thus, this stud bolt allows a resin clip to be easily fitted over the bolt.

Abstract: A driver sub and a case for enclosing a piston chamber of a percussion drill are threadedly connected by respective identical male and female screw threads. Each of the identical male and female screw threads includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.

Abstract: A fatigue resistant buttress thread. The thread has a load flank angle of approximately 30.degree. plus or minus approximately 5.degree. and a relief flank angle of approximately 46.degree. plus or minus approximately 5.degree.. The thread engaged depth is approximately 0.232 times the pitch of the thread, and the thread has a root radius approximately 0.175 times the pitch. The thread is particularly well adapted for use in cover retainers for holding valves and rupture discs in plunger pumps. Finite element analysis and actual tests indicate a greatly improved fatigue resistance compared to previously known buttress threads and other thread forms.

Abstract: A thread coupling comprises two interconnected screw threads. Each of the screw threads has a root portion shaped as a portion of an ellipse. With respect to one of the threads having such a shape, the major axis of the ellipse is longer than that of the other thread.

Abstract: A screw thread structure includes a root portion, the shape of which is defined by portions of two axially overlapping ellipses interconnected by a flat.

Abstract: A modified buttress thread has a root diameter equal to substantially .sqroot.0.7 of the core diameter with a pitch substantially equal to 1/6 of the core diameter. The thread root extends parallel to the axis of the fastener as a surface and transitions into the thread form at radii at both the load-bearing and trailing flank of the thread. The thread at its maximum diameter has a flat equal to about 0.16 of the pitch. In the fastener system the axial length along a thread form of the collar at radial locations corresponding to the locations on a mating pin are inversely proportional to the strength of the materials of the collar and the pin, for example, when the collar is aluminum and the pin is titanium the lengths are in the ratio of 60:40.

Abstract: A bone screw for use with a connecting member for connecting a bone portion with the connecting member. The bone screw includes an elongate shank having a longitudinal central axis. A first externally threaded portion receives a nut for attaching the connecting member to the bone screw. A second externally threaded portion engages a surface defining an opening in the bone portion to attach the bone screw to the bone portion. A cylindrical body portion is located on the shank intermediate the first and second externally threaded portions. The body portion engages a portion of the surface defining the opening in the bone portion to restrict movement of the bone screw relative to the bone portion in a direction transverse to the longitudinal cental axis of the shank. The body portion blocks effluent from the opening in the one bone portion.

Abstract: A push nut and a male member are disclosed having cooperating buttress threads. The push nut is divided into sectors, each of which has multiple segments that comprise the nut's thread. The adjacent edges of the successive sectors are connected to each other by a resilient corrugation arranged to distribute the stress equally between the ends of each thread segment and equally among the thread segments of each sector.

Abstract: A screw structure (10) is provided for male and female threads (14) having at least one thread (14) extending helically along a cylindrical support member (12) in spaced thread turns. A root portion (22) extends between adjacent thread (14) turns and has a curvature defined by a portion of an ellipse (24) for providing improved stress reduction during periods of severe loading.

Abstract: Axially-extending troughs in a bark of an internally-threaded collar receive setting balls of a driver that apply a torque to the collar through the balls bearing on the walls of the troughs. At a predetermined pre-load, the balls fail the bark and plow through it to develop circumferential furrows, and the torque application on the collar ends. A second torquing with balls at a different axial position fails the bark again at the same pre-load to compensate for any relaxation after the first torque application.