Abstract: A tool joint comprising a male member a female member. The male member having a coupling portion rearwardly from a body portion. The coupling portion having a frustoconical forward portion and a threaded rear portion. The thread having an intermediate section of uniform depth and terminating in forward and rear end parts. The female member having a bore extending rearwardly from a front surface. The bore having a frustoconical forward portion and a threaded rear portion. The thread having an intermediate section of uniform depth and terminating in forward and rear end parts. Upon threaded coupling of the male and female members to form a tool joint connection, the threaded portion of the male member engages the threaded portion of the female member.

Abstract: The present invention permits a screw or male member to align prior to entering a threaded section and being driven. This alignment can avoid cross threading of the screw and the internal threads as often happens with power driven screws. The present invention generally includes a device with an unthreaded section and a threaded section. A screw or male member passes through the unthreaded section prior to entering the threaded section and causes the screw or male member to be aligned before being driven.

Abstract: A nut consists of integral metal material and has a female screw threading; screw thread formed with a rolled tap in a screw hole that opens substantially perpendicularly to an end surface of one end of the nu. A concave lead-in is located at an opening end of the screw hole and has a shape including a concave curved portion and a linear tapered portion that are continuous with each other, and extend along the overall periphery of the opening end of the hole. Due to the special concave lead-in, the first thread formed by the rolled tap adjacent to the concave lead-in will not have a concave groove along its crest, although subsequent threads have such a concave groove along the thread crest as a characteristic of thread formation with the rolled tap. Such a thread structure avoids cross-threading when a bolt is engaged in the nut.

Abstract: A method and apparatus for making a nut having a first end, a second end, and defining an orifice extending between the first end and the second end. A plurality of first threads are positioned in the orifice defined by the nut body, and a malformed thread is positioned in the orifice defined by the nut body, wherein the malformed thread interrupts continuity of at least one of the plurality of first threads.

Abstract: A method and apparatus for applying coatings to a portion of the internal bore or threads of a fastener or similar article having an opening on at least one end is provided. A 360° coating with material is provided using centrifugal force to assist in direction the material to a desired surface, which does not require use of a pressurized air stream in order to propell the coating material toward the walls of the article desired to be coated.

Abstract: A threaded fastener is having a raised area or bump on a thread flank. The flank can be positioned on the nut thread or on the bolt thread. The bump forces the mating threads at least on one flank to have near zero tolerances along the pitchline of the threads and thereby eliminating play. A threaded repair insert having at least one raised area on a threaded surface also is provided.

Abstract: The invention relates to a plastic nut having a receiving bore into which a self-tapping screw can be screwed, it being the case that the receiving bore forms a through-passage region and has an adjoining, narrower region which has a diameter which allows the self-tapping screw to be screwed in, the receiving bore forming one or more steps at its transition to its narrower region via thread-like slope.

Abstract: A bushing having particularly advantageous use with heavy duty truck suspensions and including: i) a first outer bushing member; ii) a second inner bushing member defining an annular space between the first and second bushing members; and iii), an elastomeric interface disposed within the annular space between the first and second bushing members in face-to-face contact with; first and second sets of grooves formed in one of the first and second bushing members with the first set of grooves being axially spaced from the second set of grooves by a greater axial distance on one side of the grooved member than the axial spacing on the diametrically opposite side of the grooved member. In the exemplary bushings, first and second sets of grooves are formed on the inner surface of the first bushing member.

Abstract: A threaded fastener is having a raised area or bump on a thread flank. The flank can be positioned on the nut thread or on the bolt thread. The bump forces the mating threads at least on one flank to have near zero tolerances along the pitchline of the threads and thereby eliminating play.

Abstract: A fastener and an associated fastening method are provided to securely join at least two structural elements to form a structural assembly. Although the fastener can join a variety of different types of structural elements, the fastener is particularly well adapted to join composite panels, superplastically-formed/diffusion-bonded panels, honeycomb panels and hollow core panels since the fastener can securely join these structural elements without crushing or otherwise damaging the structural assembly. The fastener can also be mounted in blind installations, while providing a relatively smooth head following installation. In addition, the fastener can securely join structural elements while tolerating variations in the thicknesses of the structural elements.

Abstract: A workpiece has a surface formed by a circular bore extending in the workpiece body along a bore axis. The bore surface includes a heat-affected zone pattern thereon, produced with a laser light beam. The heat-affected zone pattern can be a variety of patterns including a single helix, overlapping helixes a single annular ring and a plurality of annular rings. The heat-affected zones can have a variety of widths, as measured in relation to the longitudinal bore axis.

Abstract: An adjustable nut is disclosed which has a body with an axial passageway therethrough for receiving a threaded shaft and a transverse bore communicating with the axial bore. A button is disposed in the transverse bore which has an elongate aperture passing radially therethrough. The elongate aperture intersects with the axial passageway such that said threaded shaft can pass through the elongate aperture. The button is urged out of the transverse bore by the biasing means but is secured within the transverse bore by the restrictive means to form an operative position and an inoperative position. The operative position mechanically interconnects mating threads on a distal end of the elongate aperture with threads on the threaded shaft. The adjustable nut can then be rotated to loosen or tighten the adjustable nut. The inoperative position is assumed when the button is depressed which moves the mating threads in the elongate aperture away from the threads on said threaded shaft.

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: The present invention relates to a male and female screw set wherein the male screw comprises at least a projecting part pressing against the flank plane of the female screw when the male and female screws are engaged. A dimensional difference is formed between the pitches of the female and male screw threads. When the female and male screws are engaged, the advancing side flank plane of the female screw thread is contacted by the advancing side flank plane of the male screw thread, while the other receding side flank plane of the female screw thread is contacted by other receding side flank plane of the male screw thread, and these respective flank planes are pressed together with tightening.

Abstract: A high-strength bolt and a high-strength nut is suited for use in combination with a standardized nut and a standardized bolt, respectively. The high-strength bolt and the high-strength nut have an external triangular thread and an internal triangular thread, respectively, of which the angle no greater than the range of each thread ridge differs by an angle of 0.degree.55' to 2.degree. from the angle of standardized thread ridges.

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 nozzle guide vane assembly has ceramic components therein having a conventional thread thereon including a preestablished pitch and having a preestablished rate of thermal expansion. The nozzle guide vane assembly has a metallic components therein having a preestablished rate of thermal expansion being greater that the rate of thermal expansion of the ceramic components is positioned in a gas turbine engine. The metallic component, a nut, has a thread therein including a plurality of crests being spaced on a pitch equal to that of the ceramic component and has a pair of contacting surfaces extending from the plurality of crests. A notch spirally extends intermediate adjacent ones of the plurality of crests and has a preestablished depth which is at least twice the size of the conventional pitch. Furthermore, the pair of contacting surfaces are in contact with only a portion of the threaded surface of the ceramic components.

Abstract: An intermediate retainer (20) for a motion transmitting remote control assembly (10) of the type for transmitting motion along a curved path includes a cylindrical sleeve (24) freely slidably surrounding a conduit (12). A cylindrical socket (26) extends perpendicularly from the sleeve (24) and includes eight elongated and resiliently deformable internal ribs (42, 44) which extend at alternating angles about an inner wall (34) of the socket (26) . The socket (26) is pressed over an extending threaded shaft (22), such as found in the engine compartment of a motor vehicle, so that the ribs (42, 44) are deformed over and tenaciously grip about the threads on the shaft (22) to help hold the conduit (12) in a routed path.

Abstract: The invention relates to a metal fixation insert for stiffening the fixation zone of a part of plastic material on a support. This metal fixation insert is made of rolled steel which is perforated.

Abstract: A screw-threaded connection incorporates multiple synchronized threads, that is, one connection element has one or more sets of male threads that mates with one or more corresponding sets of female threads on the mating connection element, in customary fashion. Of course, the multiple sets of threads on the mating connection element are synchronized such that their leads are the same, and, of course, the same as the sets of mating multiple synchronized threads. This multiple synchronized thread connection has application to any fluid connector and particularly to fluid connectors in wide-variant temperature deviation, high-pressure, and/or mechanical vibration environments.

Abstract: A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures.A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.

Abstract: A screw-threaded connection incorporates dual synchronized threads, that is, one connection element has a set of external male threads that mates with a corresponding set of internal female threads on the mating connection element, in customary fashion. The first connection element additionally includes a second set of internal female threads synchronized with the first set such that the leads of both sets of threads are the same. This second set of internal female threads mates with a corresponding set of external male threads on the mating connection element. Of course, the two sets of threads on the mating connection element are synchronized such that their leads are the same, and, of course, the same as first sets of mating dual synchronized threads. This dual synchronized thread connection has application to any fluid connector and particularly to fluid connectors in wide-variant temperature deviation, high-pressure, and/or mechanical vibration environments.

Abstract: A fastening device is provided which is a variation on the conventional nut and bolt. The bolt has a longitudinal axis and threading helically affixed thereon along the longitudinal axis. A nut having a bore extending therethrough is provided. The bore of the nut has a greater diameter than the diameter of the bolt so the bolt can extend through the bore. An array of wire bristles are affixed within the bore so as to form a brush. The wire bristles extend inwardly from the bore and are constructed and arranged of the correct size, length and stiffness to guide the bolt within the bore and to restrain the bolt within the bore as required. A variety of applications of the wire brush nut are disclosed, including a bolt capture device and a test rig apparatus.

Abstract: An electrical grounding connector, electrical grounding connector assembly, and a method of attaching an electrical grounding connector and electrical grounding connector assembly to an electrically conductive panel is disclosed. The grounding connector assembly includes a grounding stud connector having a body portion disposed between, and integrally joining, a stud portion and a riveting portion. The body portion includes a flange extending generally radially from the body portion and the flange includes a panel engaging surface and a lug engaging surface. A protective nut is adapted to engage and substantially cover the stud portion of the grounding stud connector thereby protecting the stud portion from contaminants. Barbed elements are disclosed on various surfaces of the grounding connector thereby giving the grounding connector excellent electrically conductive properties when it is assembled to an electrically conductive panel.

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: An end link and swivel assembly for chaincables, wherein the end link comprises a drilled head followed by a threaded pin which is rotatingly mounted on a passage formed at the link and secured by an adjusting nut. The pin and nut threads are of the rounded corner type, wherein between the pitches and roots thereof essentially planar flank regions as contact surfaces are defined. Therefore, the pin and nut may be manufactured by casting.

Abstract: A self-threading securing apparatus is used in combination with two tubular flow connectors to prevent the inadvertent disconnection of I.V. tubing sets. The securing apparatus includes a hollow shroud surrounding an extending cannula. The inner surface of the shroud includes interior threads for self-threading engagement with the resilient rolled-over exterior surface portion of the reseal connector.

Abstract: An adjustable length prosthetic implant includes an implant body and an axially received stem. The stem has a threaded portion and an end portion adapted for mounting with a bone. The implant body includes an end portion adapted for mounting with a bone and a tubular sleeve. The sleeve adjustably receives the stem. An adjustment nut is rotatably carried upon the sleeve for threadably engaging the stem to effect telescopic length adjustment of the stem relative to the sleeve. A jam nut is threaded over the stem and forcibly tightened against the adjustment collar to prevent accidental adjustment of the stem. The female thread formation in each of the adjustment collar and jam nut includes a wedge ramp positioned across the thread root for engaging the thread crest of the corresponding male screw formation on the stem to evenly distribute stresses through the screw formations.

Abstract: A repair device to refasten the ends of a broken strand of wire in a fence structure, especially such as a strand of barbed wire. The repair device provides at least two similar releasably interconnectable portions, each having a first medial interconnecting hook defined at a first end of an elongate wire body and a second wire fastening hook defined at the second end of the wire body. A conic wire nut is movably carried on the wire body to receive the second wire fastening hook therein and fasten upon that second hook and a loop of fence wire carried by the hook to interconnect one end of the fence wire with the second end portion of the repair device. The wire nut defines peripherally extending wings to aid manual manipulation and may be formed with a slot or releasably interconnectable portion to allow placement on the wire body after formation. More than two of the repair devices may be joined to each other to span a greater distance between wire ends to be connected.

Abstract: An attachment fitting for the fastening of a part provided with a rod onto a wall, the attachment fitting having the shape of a shank of plastics material comprising a base forming a cup for receiving a washer with claws whereas above the base are provided elastically deformable tongues allowing to clip the shank into the aperture of a wall while positively retaining the washer within the cup of the base, the attachment fitting being applicable in particular to the fastening of a shield onto a metal sheet belonging to the body of an automotive vehicle.

Abstract: A lamp shade soldering aid is used when soldering a stained glass lamp shade. The soldering aid includes a spindle, inserted through an arm, a base, a turn table, and a clamping member. A lamp shade to be soldered is inserted on the spindle and rests on the turntable, held by the clamping member. The turntable has a plurality of pivoting support members for use with the lamp shade when soldering the interior of the shade. The clamping member does not spin off of the spindle. When the lamp shade is turned, the turntable is also turned. The soldering aid provides for angular motion, such that any seam of the shade may be held in a horizontal position. The soldering aid also provides for rotating motion, such that the lamp shade may be rotated to a next seam.

Abstract: The shotshell size adapter fits into the breech of a shot gun, gas gun, grenade launcher or other gun and enables the gun to accept various sizes of shotshells and/or cartridges. The adapter includes a cylindrical mainbody which is inserted into the breech bore and a barrel which extends forwardly thereof into the gun barrel bore. The adapter barrel is releasably connected to the main body of the adapter by threads, preferably with rectangular, non-stripping lands and grooves, or by a turn wing and slot arrangement. Preferably, the front portion of the main body bore is recessed so that when the barrel is in place in the main body the bores of the main body and barrel abut each other and are concentric and of the same diameter. Alternatively, the barrel bore can be tapered to act as a shot choke. The rear end of the main body has an annular groove concentric with the main body bore and spaced outwardly therefrom to provide a finger space for lifting a shotshell or cartridge case from the main body bore.

Abstract: A screw for fixation of a tendon/bone graft during an arthroscopic surgical procedure includes a smooth conical forward end having a rounded tip and a spiral thread running from a position behind the smooth rounded forward end to a rearward end of the screw. The depth of the thread is shallower than a conventional screw and the exterior edge of the thread is rounded to decrease cutting and fragmentation of the tendon and bone. The screw includes an internal bore with left- and right-handed threaded portions for engagement with insertion and extraction instruments. In the method, the bone graft is harvested and sized as desired. A graft socket is drilled in the bone and then serially sized with increasingly larger sizing instruments to compact the bone and size the graft socket to the graft. A smooth bore screw socket is created by serially dilating a space between the graft and graft socket with increasingly larger dilating instruments, thereby also compacting the graft.

Abstract: A hollow composite internally threaded member such as a nut includes a reinforcing fabric layer such as a braided or knit layer extending in the axial direction of the member and conforming to its threads and an exterior cross-sectional configuration defined by a tubular braided triaxial fabric having axially extending elements of greater size than the remainder of the elements forming the triaxial fabric. A method of making such an internally threaded member comprises forming and embedding in a mtrix at least one reinforcing fabric layer and one triaxial fabric layer on an externally threaded cylindrical core and thereafter removing the core. Such internally threaded member may be threadedly joined and bonded to an externally threaded member of complementary thread pitch and thread diameter to form a bolt. The externally threaded member may comprise an elongate core having an integral tubular fabric layer bonded to its exterior surface.

Abstract: A self-aligning bolt has an eccentric pilot tip extending forwardly of the externally threaded shank thereof. A self-aligning nut has an eccentric counter-bore formed therein on the side of the seating face and offset from the axis of the internally threaded bore of the nut.

Abstract: A modified "Acme" type of male and female thread combination has a single-start male thread (10) of machined steel and a single-start female thread (12) of cast nodular graphite iron. The crown (20) of the female thread (12) is machined but the flanks (22, 22) and root (24) are left un-machined. There is plenty of clearance left between the crown (14) of the male thread (10) and the root (24) of the female thread (12). This reduces cost and yet the screw threads are adequate for use in a trench-box strut. The feed per revolution is 20 mm.

Abstract: An aerospace fastener comprises a blot with a roll-formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. The thread root in the run-out follows a smooth S-shaped curve with the concave portion preferably having a radius in the range of from 2P to 2.7P. The run-out extends from 1.4P to 2.3P from the maximum grip plane of the bolt, and preferably extends from 1.6P to 2P from the maximum grip plane. The root of the thread in the run-out lies within an envelope defined by boundaries which take into account the maximum and minimum material conditions of the bolt. The nut has a run-in truncating the crest of the nut thread complementary to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition.

Abstract: A hollow composite internally threaded member such as a nut includes a reinforcing fabric layer such as a braided or knit layer extending in the axial direction of the member and conforming to its threads. A method of making such an internally threaded member comprises forming and embedding in a polymeric matrix a reinforcing fabric layer on an externally threaded cylindrical core and thereafter removing the core. Such internally threaded member may be threadedly joined and adhesively bonded to an externally threaded member of complementary thread pitch and thread diameter to form a bolt. The externally threaded member may comprise an elongate core having an integral tubular fabric layer bonded to its exterior surface.

Abstract: An internal-pressure-bearing female screw adapted to be applied with a varying composite load due to variation of an internal pressure, in which the thread contact heights of the female screw are formed so as to be successively lowered along the direction of an applied tensile load, whereby the bending moments per unit length at the bottom of valleys of the respective female screw threads are equalized to reduce the maximum bending moment and the bending moment amplitude.

Abstract: A threaded fastener has a pin with a head, a cylindrical shank, a shoulder with reducing diameter, a radius at the least diameter of the shoulder whose region is work-hardened, and a threaded end, in that order. The thread extends into near-adjacency to the shoulder, and has no more than approximately one-half of a convolution of an incomplete thread at its end adjacent to the shoulder. A collar is threadable onto the thread. It has a counterbore no longer than the anticipated grip range plus approximately one-half of a thread pitch. The collar may be inherently torque-limited. The term "thread" also includes a peripheral groove.

Abstract: In a high precision oil filter, a blind engagement of a threaded coupling with a supported shaft can be made without misalignment or cross threading in the coupling by providing, for a male threaded shaft having threads of a designed pitch and peak outer diameter, a mated female coupling having threads of the same pitch and size, and providing within the female coupling a cylindrical throat having an internal diameter equal to the peak outside diameter of the male coupling and a smooth cylindrical surface of a length at least equal to three times the thread pitch and preferably equal to five times the thread pitch.

Abstract: A swage type fastener including a pin and a collar adapted to be swaged onto the pin by the application of a relative axial force by an installation tool, with the pin having a lockgroove portion, a tubular collar having an inner and outer end and adapted to be located on the pin and having a collar shank portion adapted to be swaged into the lock groove portion by the relative axial force applied between the pin and the outer end of the collar by the installation tool, the collar having a through bore which has a reduced diameter bore portion whereby the collar is generally piloted on the pin, and the collar shank portion being generally frusto conically shaped from the reduced diameter bore portion to an enlarged bore portion at the outer end, the collar shank portion having a generally uniform wall thickness from the outer end for a distance over its swageable length whereby the frusto conical shape of the collar shank portion provides a high hold-off to resist initiation of swage of the outer end of the c

Abstract: An aerospace fastener comprises a bolt with a roll-formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. The thread root in the run-out follows a concave curve having a radius in the range of from 2.0P to 2.7P and extends 1.58P to 1.8P from the maximum grip plane of the bolt. The nut has a convexly curved run-in truncating the crest of the nut thread complementary to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition. This permits the nut to be assembled on the bolt further than in a conventional combination, and shortening of the nut and bolt by at least 1P to save weight.

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 fastening system including a two piece swage type fastener including a pin and a collar adapted to be swaged into lock grooves in the pin and in which the lock grooves are helical and with the collar having a limited female thread which is threadably engageable with the helical lock grooves for variably clamping work pieces to be secured prior to swage, with the collar thread being deformable in response to a relative axial load between the pin and collar at the initiation of the swage operation but prior to swaging and in which the lock grooves are shallow and have a ratio of (h/Du).times.10.sup.2 of four (4) or less and in which the lock grooves have a simulated streamlined root contour, with the collar having a wall thickness defining a volume of material sufficient to provide overpacking of the shallow grooves of around 16%, and with the pin and collar materials having ultimate shear strengths in a ratio of around 1.8:1 to 2.

Abstract: A fastening apparatus is provided wherein the length of a mating threaded connection between two members is limited as a function of an effective differential pitch to the uniform pitch of the threads on both members whereby clearances of progressive increasing amounts are established between successive opposed tooth flanks. An elastic deformation of one member occurring in a direction opposite to the increasing of the amounts of clearance brings successive opposed flank portions into a force transmitting relationship whereby the total area of flank-to-flank contact between the threads varies as a function of the applied load.

Abstract: An aerospace fastener comprises a bolt with a roll formed thread, and a nut with a similar thread having a uniform pitch P. The bolt has a cylindrical shank, a threaded tip and a run-out zone between the shank and tip. In the run-out, which is no longer than 2P, and in preferred embodiments is in the range of from 1.6P to 1.9P, the root of the roll formed bolt thread increases diameter continuously from the minor diameter of the tip thread to the diameter of the shank. The nut has a conical run-in truncating the crest of the nut thread parallel to the run-out to clear the root of the bolt thread when the nut is assembled on the bolt in the minimum grip condition. This permits the nut to be assembled on the bolt further than in a conventional combination, and shortening of the nut and bolt to save weight. Preferably the crest of the bolt thread is at the major diameter of the tip thread at distances beyond 0.75P from the maximum grip plane of the bolt.

Abstract: A gripping device for tensioning a screwing element (2) which, at its free end, has an outer profile matching the inner profile of an engaging member (4). The screwing element (2) has an outer profile with teeth (20) of constant pitch and of constant cross-section, the mean diameter of which is generated by a truncated cone, and the engaging member (4) has an inner profile with teeth (40) of constant cross-section and of a constant pitch slightly greater than that of the screwing element (2) and generated on a conical bore of the same conicity as the outer profile (20) of the screwing element, the engaging member (4) being provided with a bearing zone (41c) which supports and transmits the forces and which is located on the peripheral part of the latter.

Abstract: A self-locking fastener includes a male member, such as a bolt, having a standard, helical, male thread of constant diameter which is deformed by the special female locking threads of a female member, such as a nut. The female threads are defined by leading and trailing flanks which converge to provide a truncated root that frictionally engages and deforms a portion of the male crest. The trailing flanks of the male and female threads are inclined at the same angle and frictionally engage each other throughout their entire depth. The leading flanks of the male and female threads diverge away from each other to provide a space adjacent the truncated female root for receiving the deformed portion of the male crest therewithin. The deformed portion of the male crest and the full engagement of the trailing flanks produces firm metal-to-metal contact between the members throughout the entire length of the female thread, thereby procluding lateral movement of one member relative to the other.

Abstract: A threaded element for forming a threaded profile in the wall of a bore formed in a material and for insertion into the bore so as to reinforce the bore. The threaded element includes a cylindrical stem having an external thread having a plurality of separate tapping lobes for cutting the threaded profile in the wall of the bore. The stem has an unthreaded radius smaller than the unthreaded radius of the bore and a threaded radius greater than the unthreaded radius of the bore. A recess is defined between each adjacent pair of tapping lobes. Each tapping lobe is defined by two cutting arcs formed at its opposite ends and a convex escape-gap arc is located intermediate the two cutting arcs. Each cutting arc has a convex configuration relative to the center of the stem, and the apex of each of the cutting arcs defines the maximum thread radius of the threaded profile, as measured from the center of the stem.