Abstract: The present invention relates to a screw, in particular a plug screw, having a screw shank (1), a screw head (2) and a tapering screw tip (4), and having a screw thread (6) that extends at least over a portion of the screw shank (1) and over the screw tip (4), the flight (6a) of said screw thread (6) having a triangular cross section as seen in longitudinal section, with two thread flanks (8, 9) that intersect at a flank tip (7). The flank tip (7) is rounded, wherein a radius of the rounding of the rounded flank tip (7) is selected to be from 1% to 10% of the nominal diameter of the screw. The thread flanks (8, 9) are each formed from two flank portions which enclose an obtuse angle with one another.

Abstract: The present invention provides a screw/bolt thread profile geometry that is particularly suited to forming a mating nut thread when the screw is inserted in to a plain diameter hole, in the anchor and rotated in a manner by which the thread helix angle will cause the relative axial forward movement, of the screw/bolt, into the anchor. This rotation and relative axial movement will be the prime mover in developing the nut thread that has mating contact with the screw/bolt thread.

Abstract: A locking screw including a male screw and a female screw, the male screw being screwed into the female screw, the male screw including male threads and the female screw comprising female threads, wherein a male thread comprises a crest side flank surface and a root side flank surface connecting the crest side flank surface and a root of the male thread, a slope of the crest side flank surface is smaller than a slope of a female flank surface of the female thread, a slope of the root side flank surface is larger than the slope of the female flank surface, a connected portion of the crest side flank surface and the root side flank surface interferes with the female thread, and a clearance is formed between the root side flank surface and the female screw when the connected portion interferes with the female thread.

Abstract: An anti-loose screw (20) includes a shank (24) having an external thread (28) with a thread angle of 63° to 68° between two flanks (34, 36) extending between a crest (30) and a root (32). A first angle (A) between one of the flanks (34, 36) and an axis (Y) extending perpendicularly to a longitudinal axis (X) of the shank (24) and passing through the crest (30) is in a range between 34° and 40°. A second angle (B) between the other flanks (34, 36) and the axis (Y) is in a range between 25° and 29°. The anti-loose screw (20) can engage with an object (40) having an internal thread (42) with a thread angle of 60° to provide an interference fit and can be formed by two dies (120, 140) each including a thread forming configuration (128, 148) having correspondingly formed ridges (130, 150) and valleys (136, 156).

Abstract: This invention relates to a self-locking screw (16; 116) in which the flanks (18; 118), which are loaded when the screw (16; 116) is screwed, are provided with an arched portion (20; 120).

Abstract: Techniques for reinforcing concrete using rebar are disclosed. Some example embodiments may include prestressed concrete structures reinforced by twisted, threaded reinforcing bars. An example reinforcing bar for a prestressed concrete structure may include an elongated, generally cylindrical rod; an external thread disposed on the generally cylindrical rod, the external thread formed from an elongated, generally nonlinear channel wrapped about a radial surface of the generally cylindrical rod in a generally helical fashion. A base portion of the nonlinear channel may be disposed substantially against the radial surface of the generally cylindrical rod and/or an upstanding portion of the nonlinear channel may extend generally orthogonally from the radial surface of the generally cylindrical rod.

Abstract: The invention relates to a self-locking nut (10) having an internal thread (12) with a core hole which has one or a plurality of regions (14) having a reduced internal diameter.

Abstract: This invention relates to a self-locking screw (16; 116) in which the flanks (18; 118), which are loaded when the screw (16; 116) is screwed, are provided with an arched portion (20; 120).

Abstract: A cutting arrangement comprises a blade shaft (32) which is mounted for drivable rotation about a blade-shaft axis of rotation (31) and which has at least one circular blade (34); and a brush roll (16) which is disposed opposite the blade shaft (32) and mounted for rotation about a brush-roll axis of rotation (15); the brush roll (16) possessing shells (37) in the cross-sectional shape of a segment of a circle which are disposed on a roll core (17) and which have an outside (39) and an inside (40) that is turned towards the roll core (17), bristles that stand out from the outside (39), torque-transmission components (44, 45, 46) for transmitting torque from the roll core (17) to the shells (37), and fastening components (49, 51) for fixing the shells (37) to the roll core (17).

Abstract: A threaded fastener includes a shank having a tip and a head configured for engagement by an associated driving tool. The fastener is configured for use with an associated threaded opening. The head is disposed on the shank opposite the tip. The shank has a helical thread formed thereon. The thread extends from about the tip to about the head and defines a plurality of zones. Each zone has a plurality of individual threads extending 360 degrees about the shank. A leading thread in each zone is formed with a wave-form profile having an amplitude that is greater than the amplitude of each prior leading thread. In one embodiment, threads other than the leading thread in each zone do not have an amplitude as great as their respective leading threads. A fastening assembly is also disclosed.

Abstract: An improved high frequency filter in a coaxial construction with one or a plurality of resonators has a thread pitch or thread pitch angle of an external thread of a thread-like tuning element which differs from the thread pitch or the thread pitch angle of the internal thread of the thread receiver at least in a partial portion of the length of the internal thread and/or of the external thread. The difference between the thread pitches or the thread pitch angles between the external thread of the thread-like tuning element and the internal thread of the thread receiver is more than 0.5%, and preferably 1% to 5%.

Abstract: A loosening preventive fastener for a screw tool formed in a relatively simple structure, easily manufacturable at low cost by mass production, and capable of easily and securely preventing a screw tool from being loosened as a fastener for a screw tool miniaturized or refined by precise processing for assembling various types of small-sized products; and a method and an apparatus for manufacturing the fastener. The fastener (10) such as a nut, an insert, etc. is to be fastened with a screw tool (30) such as a screw, a bolt, etc; and a concavity (18) is formed by press-forming from the outside in a part of the outer circumferential wall of the fastener to form a reduced-diameter deformation part (20) where the diameter of the crest or bottom of the female thread is partially reduced in the inner circumferential wall of the fastener.

Abstract: A pin with threads that extend along a portion of a stem of the pin interact with framing members as the pin pierces and is axially driven through the framing members. The interaction of the threads with the framing members cause the pin to rotate as the threads pass through the framing members and fastens the framing members together.

Abstract: A threaded fastener includes a curved-line path thread provided in a helical pattern along a shank of the fastener. The curved-line path can be provided on either side of the standard straight-line path or on opposite sides of the straight-line path. The curved-line path and can be provided on all or a portion of the thread from near the tip end thereof to near the head end thereof.

Abstract: A threaded fastener assembly includes a male threaded component having a thread and a thread advancement stop as a compression limiter for engagement of the thread in a female threaded component. A conical spring washer establishes pre-load of an assembled joint in a variable clamp design. Prevailing torque is established by a wave thread portion of the male thread in the female threaded component.

Abstract: The screw with a plurality of helix angles comprises a first section having a first thread with a first helix angle, at least one third section having a third thread with a third helix angle; and a fifth section having a fifth thread with a fifth helix angle wherein the fifth thread is identical to the first thread. The third helix angle is equal or not equal to the first helix angle. Moreover, the screw further comprises a second section connected between the first section and the third section; the second section having a second thread with a second helix angle; a fourth section connected between the third section and the fifth section; and the fourth section having a fourth thread with a fourth helix angle. A mold device for forming the screw is also included. The mold device further comprises a second mold line-symmetrical to the first mold.

Abstract: A pull type swage fastener including a pin and a collar adapted to be swaged into a locking portion on the pin shank and with a removable mandrel being threadably securable in a pull cavity at the end of the pin shank and with the mandrel adapted to be gripped by an installation tool for applying a relative axial force between the pin and collar to swage the collar into the locking portion with the mandrel being releasable from the tool and removable from the pull cavity.

Abstract: A hydraulic device having a nut part with a threaded hole which has an internal screw thread with a defined nominal diameter and with a defined, uniform pitch, and having a screw part which has an external screw thread with the same nominal diameter as the threaded hole and with a defined, uniform pitch, which is screwed into the threaded hole. (In hydraulic devices, screw parts, in particular nozzle bodies, are generally adhesively bonded in place, in order to prevent them from becoming detached. Adhesive bonding has certain drawbacks, since the screw threads have to be free of grease, and in the case of nozzles there is a risk of blockages, adhesive can enter the hydraulic circuit and also process reliability is not ensured during application.) There is provided a slight difference between the pitch of the internal screw thread of the nut part and the pitch of the external screw thread of the screw part.

Abstract: Device for securing bits of bone together, particularly small-sized bats of bone, for example bits of metatarsal head, in the form of a spindle including an elongate shank (1) followed, after a breakable region (2), by a fixator element (3) extending frustoconically to reduce in diameter in the direction of the anterior end (4), with a screw thread the pitch of which decreases progressively from the anterior end and of which the crests of the thread lie inside a coaxial geometric cylinder (D), the anterior end forming a self-drilling end.

Abstract: In a nut disengagement prevention structure, a bolt has an external thread. A nut which is thread on the bolt has an internal thread. A thread portion which is the closest to a leading end of the bolt has a first minor diameter. Any other portion of the thread of the bolt has a second minor diameter which is smaller than the first minor diameter. The second minor diameter is substantially identical with a minor diameter of the internal thread of the nut.

Abstract: A progressive (variable) pitch, interlocking thread with a tooth cross-section that is wider at its crest than at its root which creates radial clamping action when tightened into a tapped hole that has a similar thread cross-section.

Abstract: In a nut disengagement prevention structure, a bolt has an external thread. A nut which is thread on the bolt has an internal thread. A thread portion which is the closest to a leading end of the bolt has a first minor diameter. Any other portion of the thread of the bolt has a second minor diameter which is smaller than the first minor diameter. The second minor diameter is substantially identical with a minor diameter of the internal thread of the nut.

Abstract: An internally threaded body member having thread clearances includes a bore extending at least partially into the body member. The bore has a screw thread disposed therein. The screw thread has a pitch diameter increased not less than 26% of a tooth height of the thread.

Abstract: The invention relates to a threaded pin for holding together pieces of a fractured bone. The pin comprises a body having a distal end and a proximal end. The distal end has a first thread presenting crests and the proximal end has a second thread presenting crests. The first thread and the second thread being spaced apart by a smooth portion. The first and second threads are such that the pitch X of the first thread and the pitch Y of the second thread both decrease from the distal end (X1, X2, Y1, Y2) towards the proximal end (Xn, Xn−1; Yn, Yn−1). The diameter d of the crests of the first thread and the diameter D of the crests of the second thread both increase from the distal end (d1, d2; D1, D2) towards the proximal end (dn, dn−1; Dn, Dn−1), and the values are such that: X1>X2>Xn−1>Xn>Y1>Y2>Yn−1>Yn and Dn>Dn−1>D2>D1>dn>dn−1>d2>d1. The invention is applicable to repairing bones.

Abstract: An inner barrel includes a male helicoid, and an outer barrel includes a female helicoid which can engage with the male helicoid of the inner barrel. The included angle of trapezoidal threads of the male helicoid are identical to an included angle of trapezoidal grooves of the female helicoid in a section perpendicular to a direction of an extension of the threads.

Abstract: The anchor bolt comprises a generally hollow body (1) with a drilling end (4), a supporting collar (5) at the other end and an external screw thread (6). The collar (5) forms two openings (10, 11), diametrically opposed, for receiving an anti-rotation pin (8, 9) removably fixed to the collar (5) and movable in the opening (10, 11). The pins (8, 9) are intended to anchor both in the collar (5) and in the receiving material, in order to prevent rotation of the bolt.

Abstract: An arrangement for detecting a fatigue fracture caused by overstressing of a bolted connection including a bolt and an internal-thread-bearing hollow section which is alternately stressed by an axial flux of force between zero and different maximal values. A transverse crack forms at a predetermined breaking point of the bolted connection, at which the hollow section breaks due to fatigue. The spacing of the predetermined breaking point from the connection ends, and the interaction of the bolt and the hollow section, are designed such that, after the breakage, the bolt forms in the hollow section a residual joining connection which can be alternatingly stressed. In order to signal the occurrence of a crack on the hollow section of the bolted connection in the event of a fracture caused by fatigue in a simple and always noticeable manner, the arrangement has an additional signaling device.

Abstract: A bone screw having a continuously varying pitch includes a tapered root portion having a relatively small diameter on a leading end of the screw and a larger trailing diameter. The pitch of the screw decreases between the leading and trailing ends thus causing the bone fragments in a fracture to be drawn together when the screw is installed across the fragments. The radially outer diameter of the threads increases between the leading and trailing ends thus causing each successive thread portion to cut into bone radially outwardly from the preceding thread portion thereby providing uncut bone in which the succeeding threads can gain purchase.

Abstract: A connector assembly that is subjected to alternating loads by an axial flow of force between zero and various maximum values, with an outer assembly component designed as a hollow section and an inner assembly component located in the outer one and fitting by virtue of its shape. In order to detect failure of the assembly caused by a fatigue fracture produced by overloads at the end point in the assembly direction, even before it develops, in a simple fashion within the functional assembly, the assembly comprises a rear area with play that begins at the end of the connection that points in the assembly direction and a forward zero-play area of the inner assembly component that abuts the latter and is located inside the outer assembly component.

Abstract: A prevailing torque type lock nut for assembly onto a threaded bolt that affords a substantially 360 degree break loose torque engagement resistance against the standard bolt threads and is comprised of a compressively controlled height reduction as compared to a standard nut of like size.

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: The screw of this invention can be used for fastening members of a variety of materials and reliably prevent loosening of the screw. The screw shank is formed with two threads, a main thread for driving the screw and a sub-thread which extends in the same direction as the main thread, is smaller in outer diameter than the main thread and has a pitch different from the main thread. The inclination of the slant surface of the sub-thread is set steep on the loosening side and moderate on the fastening side. The pitch of the main thread is set larger than that of the sub-thread. When the tightened screw is applied a loosening torque, the sub-thread bites into the inner wall of the hole, preventing the screw from being loosened.

Abstract: A bone screw having a continuously varying pitch includes a tapered root portion having a relatively small diameter on a leading end of the screw and a larger trailing diameter. The pitch of the screw decreases between the leading and trailing ends thus causing the bone fragments in a fracture to be drawn together when the screw is installed across the fragments. The radially outer diameter of the threads increases between the leading and trailing ends thus causing each successive thread portion to cut into bone radially outwardly from the preceding thread portion thereby providing uncut bone in which the succeeding threads can gain purchase.

Abstract: Self-locking alignment pin and method for aligning a nuclear fuel assembly with respect to a core plate disposed in a nuclear reactor pressure vessel. The fuel assembly has a top nozzle having a first bore formed therein. The core plate has a second bore alignable with the first bore. The second bore has first threads of a first predetermined pitch and second threads of a second predetermined pitch. The alignment pin further includes a shaft that has an end portion having third threads of the first predetermined pitch for threadably engaging the first threads of the second bore. A flange, which has a plurality of recesses in the underside surface thereof, surrounds the shaft and is integrally attached thereto. A locking member surrounds the flange and has exterior fourth threads of the predetermined second pitch for threadably engaging the second threads of the second bore.

Abstract: A connector of the nut-and-bolt type with a bolt that has an external thread and/or a nut that has an internal thread. The connector has a locking device that provides a moment of friction that counteracts the unscrewing moment. The pitch of the external thread differs from that of the internal thread. The external thread is screwed far enough into the internal thread or vice versa for the moment of friction of the locking device to result, once the flank clearance between the two threads has been completely occupied and exceeded, from the forces that occur during resilient deformation.

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: A threaded connection in which the axial load between a screw and nut in a tightened condition of the connection is distributed more uniformly between different turns of the engaged threads than in a standard threaded connection by forming one of the threaded elements, preferably the nut, to have a pitch which increases progressively as the thread advances helically in a predetermined axial direction, while the other thread desirably has a pitch which is uniform along its length. The pitch of the first thread may increase at a rate predetermined to compensate for differences in the tensile force which is applied to the screw and the compressive force applied to the nut at different points along their length when the screw and nut are tightened together to a prestressed condition.

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 fatigue resistant threaded connection includes a nut having two threads which are aligned axially but turned relative to one another about their common axis through an angle great enough to cause development of large axial forces between the screw and nut threads when they are connected together, resulting in improved distribution of load forces between the two threads of the nut and improved resistance of the screw and nut to fatigue and tensile failures.

Abstract: Apparatus for repairing a casting having a crack therein comprising a metal lock to extend across the crack and a lacing plug to fit in the crack, the metal lock formed as a rigid elongate member having a plurality of lobes formed from adjacent portions that are circular in cross-section and each having its center on the longitudinal axis of the elongate member, said lobes being of alternating large and small diameters and including a central large diameter lobe and at least one outer large diameter lobe at each side of the central large diameter lobe, said central large diameter lobe being spaced from each outer large diameter lobe by a small diameter lobe and with each lobe overlapping its adjacent lobe and extending through the elongate member; and the lacing plug including a head configured to receive a driving tool, a tapered shaft, a shoulder at a top of the tapered shaft, a non-threaded shaft portion interconnecting the head and the tapered shaft, a break-off groove formed in the non-threaded shaft por

Abstract: A fastener assembly, having a threaded male and female member, is disclosed. One of the members has substantially conventional threads and the other member has two threaded portions rotationally offset relative to one another. Direction of the offset determines whether a compressive or tensile preload force occurs in the assembled fastener. Magnitude of the preload force is controlled by the extent of the offset. One of the threaded portions includes at least two, preferably about four, tapered threads which permit gradual distribution of the preload force and thereby prevent plastic deformation of the threads. The assembled fastener is substantially vibration proof, and, due to the well controlled permanent preload force, is highly fatigue resistant.

Abstract: A plastic cap for glass or plastic carbonated beverage bottles is shaped so that in use pressure is exerted around the edges of a gasket to give enhanced sealing. A single cap can fit the different necks of standard glass and plastic bottles. Its heat-shrinkable skirt has longer portions between connectors.

Abstract: A fatigue resistant self-locking fastener is formed by screwing two threaded elements into engagement with a part having a thread which is slightly off-size with respect to the threads of those elements, locating the two elements just in contact with one another while in engagement with said part but without tightening them against one another sufficiently to develop any substantial stress in the threads, and then securing the elements together in that relative position, preferably by welding.

Abstract: A threaded fastener assembly comprises a bolt with standard 30.degree. flank V-threads and a nut with 30.degree. flank V-threads modified to have wedge ramps between adjacent top and bottom flanks and characterized by the uniform pitch of the nut threads being a predetermined amount less than the uniform pitch of the bolt threads so that there is flank to flank contact between the engaging nut and bolt threads a the top of the nut and the bottom of the nut.