Abstract: A fluid control valve and manufacturing method thereof, wherein, when a pressing force acts on the engagement surface between a diaphragm member and a valve seat-contacting member, the valve seat-contacting member is not displaced and no gap is formed. The diaphragm member made of a first fluorine-based resin material is provided with a diaphragm membrane and a rod-shaped part in the center of the diaphragm membrane. The valve seat-contacting member made of an injection-moldable second fluorine-based resin material is provided with a ring-shaped sealing surface and a recess on the opposite side from the ring-shaped sealing surface. The rod-shaped part is partly fitted into the recess. A ring-shaped recessed is formed on outer circumference of a portion of the rod-shaped part. A small diameter recess is formed on the inner circumference of the recess. The ring-shaped recess section and the small diameter recess adhere closely to form the engagement surface.

Abstract: A thread form for a threaded connection comprising a plurality of threads, wherein at least a portion of each of the threads comprise a root having a root radius that extends from a point central to the root and having planar flanks extending from both sides thereof.

Abstract: An orthopedic fastener (10) has a head (50) and a shank (20). The shank (20) extends from the head (50) to a distal tip (11). The shank (20) has a leading end (1) adjacent the distal tip (11) and a trailing end (3) adjacent the head (50). An intermediate transition (2) is positioned between the leading (1) and trailing ends (3). The leading end (1) has first threads (40) with one or more self-tapping cutting grooves (41) extending adjacent the distal tip (11) and through a plurality of the first threads (40). The trailing end (3) has a second thread (60) extending toward the head (50) from the intermediate transition (2). The intermediate transition (2) has one or more second cutting grooves (61) extending from at least a first thread (40) in the intermediate transition (2) through at least one of said second threads (60) to initiate tapping of the second threads (60) into cortical bone.

Abstract: A bone plate system for internal fixation of bone fractures includes a bone plate having a plurality of bone plate holes. The holes are constructed to receive either a non-locking, locking, or variable-angle locking bone screw. The holes have discrete columns of teeth or thread segments arranged around the inner surface of the hole for engaging threads on the heads of locking and variable-angle locking bone screws. Conventional locking bone screws engage the bone plate coaxially with the central axis of the bone plate hole. Variable-angle locking bone screws can engage the bone plate at a selectable angle within a range of selectable angles relative to the central axis of the bone plate hole. The head of the variable-angle locking screw is at least partially spherical, and the thread thereon has a profile that follows the arc-shaped radius of curvature of the spherical portion of the screwhead.

Abstract: A wave threaded fastener and system. A wave thread extends from the outer surface of the body and is made up of a profile wave and a lateral wave. The profile wave includes a plurality of profile crests and profile roots defining a plurality of profile thread widths. The lateral wave includes at least one lateral crest and at least one lateral root defining at least one wave period. Each wave period forms a period arc having a period arc angle and the sum of all period arc angles about the lateral wave equals three hundred and sixty degrees. Each of the profile crests and roots are aligned with corresponding lateral crests and roots and the wave thread travels one profile thread width per each period arc traveled.

Abstract: A fastener includes an elongated body having a first end and a second end, a helical thread having a crest, a root, and flank portions formed on at least a portion of the elongated body, and at least one protrusion extending from the crest and flank portion. The at least one protrusion is an axially extending V-shape of the crest, flank portions, and root of the helical thread with a peak of the at least one protrusion having a ridge that extends radially outward from the root of the thread.

Abstract: A fastener includes an elongated body having a first end and a second end, a helical thread having a crest, a root, and flank portions formed on at least a portion of the elongated body, and at least one protrusion extending from the crest and flank portion. The at least one protrusion is an axially extending V-shape of the crest, flank portions, and root of the helical thread with a peak of the at least one protrusion having a ridge that extends radially outward from the root of the thread.

Abstract: A loose resistant nut fastener includes a nut body that has a first end face, a second end face opposite to the first end face, a peripheral face connected between the first and second end faces, a threaded hole extending along a first axis and extending from the first end face toward the second end face, an engaging hole that extends from the second end face toward the first end face and that is disposed at one side of the threaded hole, and a slit that extends from the peripheral face toward the first axis and that is disposed between two axially opposite ends of the threaded hole. The nut fastener further includes a tightening component to engage the engaging hole.

Abstract: A threaded fastener having a threaded portion with a ratio of pitch diameter to minor diameter less than 1.28, and the threaded portion with a major diameter portion, a leading flank having a normal angle between 10° and 60°, a trailing flank having a normal angle between 1° and 30°, and a shank portion extending between the trailing flank and the leading flank of adjacent threads of a arcuate surface having a radius greater than the thread height. The arcuate surface forming the shank portion may have a radius between 1.2 and 1.8 times the thread height.

Abstract: A fastener is provided including an elongated body having a first end and a second end, and a helical thread formed on at least a portion of the elongated body where the thread has a crest, a root, and flank portions. The helical thread has at least one protrusion extending from the crest and flank portions toward the first end of the elongated body, and each protrusion has a peak that extends to the root of the thread.

Abstract: A threaded connector includes a base and a threaded male portion projecting axially outward from the base. The threaded male portion is adapted to mate with an associated threaded female socket. The threaded male portion includes a helical thread comprising three sections: (i) a lead-in section; (ii) a transitional cam-locking section; and, (iii) a friction-locking section. The friction-locking section is located adjacent the base, the lead-in section is spaced from the base, and the transitional cam-locking section connects the lead-in section to the friction-locking section. The helical thread includes a tip and a root. The lead-in section is defined by a first major diameter at the tip of said thread and the friction-locking section is defined by a second major diameter at the tip of the thread. The second major diameter is greater than the first major diameter.

Abstract: It is possible to prevent a screwing torque from becoming excessively high even when a screw is threadedly engaged into a deep guide hole. In a tapping screw 100 comprising a parallel screw 22, a taper thread 23 provided closer to a tip end of the tapping screw than the parallel screw 22, and a plurality of projections 30 which partially project along an apex and flanks on both sides of a screw thread and which form an internal thread on a surface of a guide hole formed in a to-be fastened member, the plurality of projections 30 are provided from a region where the taper thread 23 is provided to a portion of a region where the parallel screw 22 is provided, and a diameter of a virtual cylinder which comes into contact with tip ends of some of the projections 30 including a projection provided in a region where the parallel screw 22 is provided is larger than an outer diameter of a external thread of the parallel screw 22.

Abstract: A screw comprising a first member having a plurality of alternating first thread ridges and first thread grooves, a ridge width of the first thread ridges being larger than a groove width of the first thread grooves at a measurement diameter of the first member. The measurement diameter is determined by calculating a pitch diameter of a hypothetical member having a plurality of hypothetical thread grooves and hypothetical thread ridges, with the hypothetical thread grooves being identical to the first thread grooves, and with the hypothetical thread ridges and the hypothetical thread grooves having identical, but opposite, profiles, and with the measurement diameter being identical to the pitch diameter of the hypothetical member.

Abstract: Prior to engaging a male screw formed on the outer circumference of a second member with a female screw formed on the inner circumference of a hole in a first member, protruding parts which protrude outward in the radial direction and are positioned at one end side of the male screw in the axial direction are formed in a plurality of regions which are separated from each other in the circumferential direction on the outer circumference of the second member on which the male screw is formed. The male screw is then engaged with the female screw from the other end side of the male screw in the axial direction. The torque required to rotate the male screw engaged with the female screw in the loosening direction is set so as to be greater in a state where the protruding parts are interposed between the male screw and the female screw than in a state where the protruding parts are not so interposed.

Abstract: A flat portion 12a and a slope portion 12b are provided on a thread 12 of a multi-pitch screw 10 alternately. The flat portion and the slope portion are provided on the thread of a multi-pitch nut which fastens with this. Consequently, a screw and a nut capable of preventing loosening securely by step are achieved. This enables comfortable and quick feeding and when a torque from a driving source is interrupted, step-like self-lock is activated.

Abstract: A protective device for use with an interference screw used to attach a soft tissue graft within a bone tunnel reduces the tendency of the interference screw to undesirably snag a soft tissue graft and/or sutures when screwed into a bone tunnel. The protective device has an angled face that corresponds to an angled face of the interference screw and threads that correspond to the threads of the interference screw. When used together, the protective device effectively completes the part of the interference screw that is removed to form the angled face. This, in turn, reduces or eliminates any sharp edges that would otherwise catch or snag the tissue graft and/or sutures as the interference screw is screwed into a bone tunnel during a joint repair procedure. The protective device may be included within a kit together with a correspondingly sized and shaped interference screw, and optionally with a driver.

Abstract: The invention relates to a screw fastener comprising a threaded shank having a force application means for torque transmission and a screw fastener point. The threaded shank consists of a shank core and a self-tapping thread, and the thread is designed as a prominence which runs helically over the shank core, is defined by two flanks meeting in an outer thread edge and has a radial height (H). The outer thread edge, at least in a section of the thread, runs in a wavelike manner in the radial direction with an amplitude between wave crests having the height (H) and wave troughs having a height (h) reduced by the amplitude.

Abstract: A screw, driving device, and method are provided for repairing a tissue injury of a patient, such as a meniscal tear in a knee or osteochondritis dissecans. The screw has a root, a distal section having a narrowing cross section toward the distal end, and a thread along at least a portion of the root between the proximal end and the distal end. Along a leading section extending from the distal end, the helical pitch is substantially constant; along a trailing section between the leading section and the root's proximal end, the helical pitch decreases. The substantially constant pitch along the leading section assists in preventing a stripping of the helical section. At the proximal end is a head having a diameter greater than a major root diameter of the central section. The head is for improving the tissue retention characteristics of the screw.

Abstract: A male threaded fastener particularly suited for use in plastics has a high thread and a low thread. Depressions are provided in the pressure flank of the high thread. Dimensional relationships are defined for scaling the fastener to commonly accepted sizes.

Abstract: A male threaded fastening member is provided with depressions in at least one or several helix wraps of the thread adjacent the head, the depressions extending inwardly from an edge of the thread at least part way toward a shank of the male fastening member. In a fastening system including the male fastening member, a female member includes projections for engaging the depressions.

Abstract: Screw provided with self-locking rolled thread, wherein, in a plurality of places along its extent, the thread is deformed in relation to the normal thread cross section in that the thread outside diameter is reduced by radial compression of limited thread portions, the area of the thread cross section being substantially identical to that of the undeformed thread. While maintaining the slant of the thread flanks, the thread cross section is symmetrically widened in the outer region and reduced in the adjoining inner region, the transition from the widened to the reduced thread cross section lying approximately in the centre of the respective thread flank, and the limited thread portion extends over two parts of a thread turn such that there result two symmetrically opposite thread portions each of approximately ? of the thread turn.

Abstract: A fastener includes a main body having a number of spaced ridges formed on an outer periphery thereof. The ridges are arranged along a helix. At least one of the ridges has a retainer extending in a direction that is at an angle with an extending direction of the ridge. In another embodiment, a fastener includes a main body having a number of spaced ridges formed on an outer periphery thereof. Each ridge extends along a direction that is parallel to a longitudinal direction of the main body. At least one of the ridges has a retainer extending in a direction that is at an angle with an extending direction of the ridge.

Abstract: A screwed connection has a first connecting means with an external thread and a second connecting means with an internal thread. In order to avoid self-slackening of the screwed connection, the external thread has a denticulation (14-16) which interacts with a mating denticulation of the internal thread.

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 fastener, driving device, and method are provided for repairing a tear in soft tissue of a patient, such as a meniscal tear in a knee. The fastener has a distal section having a narrowing cross section toward the distal end and a helical protrusion along a central section between the proximal end and the distal end. Along a distal section extending from the distal end, the helical pitch is substantially constant; along a central section between the distal section and the proximal end, the helical pitch decreases from the distal end to the proximal end. The substantially constant pitch along the distal section assists in preventing a stripping of the helical section. At the proximal end is a head having a diameter greater than a major root diameter of the central section. The head is for improving the tissue retention characteristics of the fastener.

Abstract: A threaded member such as a bolt, nut, or pipe has a threaded portion on a body of the member. The threaded portion of the member includes a first threaded section, a second threaded section, and a third threaded section. The first and third threaded section have standard threads which comprise standard roots, flanks, and crests. The second section is between the first and third sections and has threads in which a portion of the threads are raised relative to the standard threads to define bumps. The raised sections or bumps comprise a raised root, a raised flank, and a raised crest. The raised root and raised crest define diameters different from the diameters of the standard root and standard crest, respectively. In a exteriorly threaded member, the raised root and crest have diameters greater than the diameter of the standard root and crest, respectively. In interiorly threaded member, the raised root and crest define diameters smaller than the diameters of the standard root and crest, respectively.

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 conductive male thread (22) has a thrust bearing flank (22a) coated with an insulating paint layer (23), and a conductive female thread (12) has a thrust bearing flank (12a) formed with a conductive projection (13) to break through the paint layer (23) and bite in that flank (22a).

Abstract: A method of preventing vibration loosening of a clamping screw 26 of a circuit protection apparatus 10 is provided. The circuit protection apparatus 10 has a conductor receiving member 28 including a conductor receiving opening 40 for receiving an electrical conductor 46 therein. The conductor receiving member 28 has an aperture 42 extending from a surface 50 thereof into communication with the conductor receiving opening 40. An overall extent of the aperture 42 includes threads. The method provides a clamping screw 26 having a threaded shaft 50. The threaded shaft 50 has a surface feature 52 in the threads thereof near an end 54 of the shaft.

Abstract: Self-tapping screw having an at least partially non-round enveloping curve for the thread and having a penetrating section and a retaining section, it being the case that the penetrating section contains a plurality of successive thread stages which each have at least one thread turn and, along the thread stage, have essentially the same, aligned enveloping curve which runs either cylindrically or elliptically, the thread stages with an elliptical enveloping curve (elliptical thread stage) being combined such that the major axes of the successive elliptical thread stages, forming a stage group, are offset with respect to one another.

Abstract: An auger is produced from a material such as plastic. The auger includes a shaft with a first pointed end having a thread member thereon. A second end of the auger includes an opening. Handles extend perpendicularly from the shaft and near the opening. The threads are formed in a manner to facilitate removal of the auger from a mold in which the auger may be formed using a plastic-type material. On opposite ends of the shaft, the thickness of the thread is increased to provide a clearance for the thread so that the completed auger may be readily removed from the mold.

Abstract: A screw comprising a shank having an upper portion formed with spiral circular threads and a lower portion formed with spiral triangular threads, each of said spiral triangular threads having three sharp edges and three pointed tips, said pointed tips of said spiral triangular threads being located at different positions, whereby the screw can be easily and rapidly turned into a piece of hard wood.

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: 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 male screw which has a protrusion protruding from a thread thereof at least with regard to the normal direction to a flank of the thread. To obtain such male screw, a blank is introduced between rolling dies which are moved relative to one another and is rolled between the rolling dies to be formed with a thread. In this thread rolling process, the rolling pressure on an area of a die face of at least one of the rolling dies is determined to be higher than that in ordinary thread rolling process and the rear end portion of the area of the die face is made to bite into the blank, causing the corresponding portion of the blank to be forced out to form the protrusion.

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: A bone screw having a helical thread with a constant outside diameter and curling around a tapered core. The fine screw tip and thread at the tip of the screw can be inserted into a bone with minimal tearing or cracking of the bone. The thicker core just below the screw head increases the screw's ability to withstand compressive and distractive loads. The core is thickest just below the head because it is at that point on the screw that the fulcrum loads are greatest.

Abstract: The fastener, which is especially adapted for bones, consists of a shaft (2) bearing a thread (1) with variable pitch, a front end (3) and a rear end (4).The thread (1) is present over the entire area of the shaft (2), and in the area of the rear end (4) is characterized by a smaller pitch than in the area of the front end (3).Thanks to the diminishing pitch of the thread (1) in the proximal direction, a locally differentiated intraosseous pressure generation takes place. In accord with the well-known Wolff's Law, this leads to a controlled bone growth along the loading axis and thus an improvement in the stability of the implanted fastener.

Abstract: A threaded fastener that self locks as it is tightened to a fastened object. The thread includes one or more portions that are shifted, resulting in one or more discontinuities in the thread. Each shifted portion of thread is fully formed at the discontinuity. The shifted portions will deform a relatively softer female thread, causing the deformed thread to move up and over the end faces of the shifted portions and to pack up in front of the end faces to prevent any significant loosening of the connection.

Abstract: A self-tapping, screw-type masonry anchor which can readily be turned into a hole drilled in a masonry structure to secure an object thereto, the installed anchor being highly resistant to pull-out forces. The anchor, which is fabricated of hard metal, includes a head engageable by a torque-producing tool to rotate the anchor, and a shank extending therefrom provided with a root section surrounded by a helical male cutting thread whose series of convolutions have sharp crests and extend from the leading to the trailing end of the root section. The crests of the male thread diameters are greater than that of the hole and decrease progressively from the leading to the trailing end to create a reverse taper. When the anchor is screwed into the drilled hole to tap its wall, the large diameter crest at the leading end of the male thread cuts an internal female thread in the wall having convolutions of substantially uniform diameter which intermesh with the reverse-taper convolutions of the male thread.

Abstract: A self-tapping screw-type masonry anchor which when turned into a hole drilled in a masonry structure to secure an object thereto is then highly resistant to pull-out forces. The anchor is fabricated of a metal whose hardness is such that when it rubs against a masonry surface it is abraded and worn thereby. The anchor includes a head engageable by a torque-producing tool to rotate the anchor, and a shank extending therefrom provided with a root section surrounded by a helical male cutting thread whose series of convolutions have sharp crests and extend from the leading to the trailing end of the root section. The crests have diameters greater than that of the hole which decrease progressively from the leading to the trailing end to create a reverse taper.

Abstract: A threaded connection structure for rotatably connecting and disconnecting adjoining members including a female member having annular internal pitched threads and a male member for threading into the female member having outer threads complemental to the threads of the female member with raised areas along the axial faces of the threads of one of said members to cause areas of concentration of unit pressure between the threads so that unwanted rotation and unwanted unthreading is prevented. A flange is provided on one member to engage a shoulder on the other member for continued axial surface pressure of the raised areas.

Abstract: A locking nut is provided by forming a straight cylindrical bore through a body, forming a tap with uniform teeth, the tips of which taper at a shallow angle toward one end of the tap, and tapping said bore with said tap so as to produce a thread having a pitch diameter and a root diameter which taper from one of the thread to the other, and a crest which is of constant diameter and increasingly truncated from one end to the other, said thread at said one end having substantially a full profile.

Abstract: Reusable self locking fasteners, and methods of making the same wherein the self-locking characteristic is derived from a metallurgically bonded metal patch comprising a metal or metal alloy selectively applied to a specific region of the threaded surface of the metal fastener in a metal paste or powder form and fusing the same under heat. The metallic patch so achieved may comprise a single metal or metal alloy or a composite of metals or metal alloys selectively and metallurgically bonded to the threaded surface of the metal fastener by single or multiple metal paste or metal powder applications.The convex/concave curve of the fused metal having a radial thickness,1. that is greatest substantially midway between the two radial planes, and2. that gradually diminishes from the midway point as the material approaches the radial planes in order that the exposed surface of the material forms only a small angle to a tangent to the surface of the threads at the radial planes.

Abstract: A bone screw having a helical thread that gradually increases in thickness from the tip to the head of the screw. The thin thread at the tip of the screw can be inserted into a bone with minimal tearing or cracking of the bone. The thicker treads ascending form the tip to the head of the screw displaces bone against the superior (top) thread surfaces. This displacement of bone increases the screw's resistance to being pulled-out of the bone. The thicker core just below the screw head increases the screw's ability to withstand compressive and distractive loads. The core is thickest just below the head because it is at that point on the screw that the fulcrum loads are greatest.

Abstract: A connector for joining the ends of two pipes has a pair of half-sleeves, which fit around the pipe ends to form an inner sleeve. The inner sleeve has a tapered or conical outer surface, against which an outer sleeve presses. The outer sleeve is a single-piece sleeve with a tapered bore, the angle of the taper of which matches the angle of taper of the outer surface of the inner sleeve. The outer sleeve is slid over the inner sleeve and is clamped in intimate contact with the inner sleeve by a nut which is tightened onto a threaded end of the outer sleeve while an annular, inwardly - projecting flange of the nut bears against the ends of the half-sleeves. The surfaces of the half-sleeves are coated with adhesive before being placed around the pipe ends; this adhesive cures while the joint components are clamped together. Preferably each half-sleeve has a central rib at its mid-point, against which the ends of the pipes being joined abut.

Abstract: The invention provides a screw nut comprising a central inner thread and a radially extending slit, the width thereof essentially corresponding to the diameter of the central inner thread. Thus, a threaded bolt or a threaded stud can be radially inserted into said screw nut body. In order to avoid that the screw nut is displaced away from the threaded bolt or stud during tightening of the screw nut, the central inner thread comprises a plurality of thread turns provided with axially extending recesses directed towards the end surface of the screw nut which is under load when the screw nut is tightened on the threaded bolt or stud.

Abstract: A flooring system comprising a flooring panel having a panel body, and detachable support legs is disclosed. The panel body has a set of threaded holes having internal threads of a given pitch extending uniformly throughout the hole (the regular threads). One end of the detachable support legs is provided with a threaded section having two types of external threads of the identical pitch to the internal threads; one type is the regular threads and the other type has the crest of each thread wider than the crest of the regular threads, and the wider crest is formed with a slit extending continuously on the tip of each crest (the split threads). At least the leading end the threaded section of the leg is provided with the regular threads. The placement of the regular and split-threads can be reversed on the panel body and on the threaded section of the leg, to achieve the same purpose of providing firm and efficient locking system.

Abstract: A fastener for insulated roofing comprises a non-metallic, screw-threaded shank, having a penetrating point at one end of the shank and a transverse plate carried at the other end of the shank. The shank and transverse plate are preferably integrally method out of a polyetherimide resin formulation which has a tensile strength of at least 15,000 psi. as tested by ASTM D638. Such a fastener has a great advantage in terms of cost and lack of corrodability, while still exhibiting the required strength. Also, a universal driver socket is provided.

Abstract: A bearing structure in particular for use in a meter having an axis of a pointer comprises a bearing support member having an internal thread and bearing member for supporting the axis rotationally, and the bearing member adapted to be fixed to the bearing support member, and the bearing member being formed of a synthetic resin and having an outer periphery. On the outer periphery of the bearing member, there are formed at least one complete thread portion having an external thread formed on the outer periphery of the bearing member, the external thread adapted to be screwed into the internal thread of the bearing support member, and at least one incomplete thread portion formed on said outer periphery, thereby the bearing being fixed to the bearing support member by screwing the incomplete thread portion into the internal thread of the bearing support member compulsorily.