A metal component (112) made of a base metal and a coating system (500) thereon is characterized in that the coating system comprises a conductive layer (502) on the base metal and a resin- based layer (504) including conductive pigments (508) on the conductive layer. The conductive pigments (508) form electrically conductive 3D-networks in the resin, with the networks being randomly distributed in the resin. Aerospace fasteners having a coating system of a nickel flash on the base metal, and a phenolic resin-based coating including nickel fibers on the nickel flash, are also provided. Further, a method for coating a metal component is disclosed. The coating system (500) may be applied to metal components, including aerospace fasteners such as pins, bolts, collars, nuts and nut plates, and washers, as well as studs, latches, helicopter rotors, and landing gear structures.
Disclosed is a pin clamp (100) for the temporary assembly of at least two perforated structural parts (200a, 200b), comprising a main tubular body (10) extending along a longitudinal axis X and having a bearing face (151) intended to come into contact with a first face (201a) of the structural parts, a clip (20) able to pass through opposite perforations, produced in said parts, the clip being translationally movable along the longitudinal axis, driven by the rotation, about said axis, of a tie rod (40) provided with a tapped bore (41) engaging with a threaded end (21) of the clip, the clip (20) comprising branches (22), each ending with a catching spur (23) intended to come into contact with a final face (202b) of the structural parts, the branches being able to radially and progressively separate along a separator (30), which is placed between the branches and is fixed relative to the main body (10), under the effect of the recoil of the clip, the separator (30) comprising a transverse part (32) introduced into a longitudinal groove (24) of the clip and rotationally blocked in a groove (111, 131) provided in an element that is fixed relative to the main body.
TOOL FOR INSERTING A FASTENER INTO A STRUCTURE BY INTERFERENCE AND INSTALLATION METHOD FOR INSTALLING A FASTENER IN A STRUCTURE BY INTERFERENCE USING SUCH A TOOL
The invention relates to a tool (20) for installing a fastener (10) into a drilling in at least one structure by interference, said fastener (10) comprising a head housed in an insert clamp and a grasping element, said tooling comprising a first body (30) extending along a first main axis and having: - at least one load-reacting surface, of which one also constitutes a surface for the application of a load; - a load transmission surface, and - a housing extending along the first main axis from a first end of said first body, said housing being extended along the first main axis by a drilling extending from said housing as far as a second end of said first body. According to the invention, the load transmission surface is situated at the second end of the first body (30) and extends perpendicular to the first main axis, said load transmission surface being dimensioned to be able to bear simultaneously on the head and on the insert clamp. The invention also relates to a method for installing a fastening into a structure by interference using such a tool.
The present invention relates to a fastener (210) for the temporary assembly of at least two pre-drilled structures, having: a hollow body (22); elastic clips (24) that are movable with respect to the body, one end of each elastic clip comprising a catching spur (50); a spacer (30) disposed between the elastic clips; an actuating element (32); a first (34) and a second (36) elastic return element, disposed inside the body. One end of the spacer has a stem (62, 66) and a bulb (64), the elastic clips being able to deform radially between a retracted configuration, corresponding to the catching spurs (50) being disposed around the stem (66), and a deployed configuration, corresponding to the catching spurs being disposed around the bulb.
The invention relates to a fastener comprising a substantially right circular cylindrical surface arranged along an axis, said surface comprising a grooved shape selected from a thread, a tapping and a plurality of traction grooves, said fastener being made of a beta-metastable titanium alloy. The alloy has a microstructure (40) made up of a matrix (42) and alpha phase nodules (44) distributed in said matrix, the matrix being made up of beta phase and groups (46) of alpha phase lamellae (48) oriented in the same direction.
The present invention relates to a fastener (10), comprising: a screw (30) comprising a threaded portion (36); and a sleeve (32) comprising a body (68) and a tapped portion (66); the threaded portion of the screw comprising: a first part (43) arranged inside the body of the sleeve; and a second part (44) adjacent to the first part and joined to the tapped portion (66) of said sleeve; the fastener further comprising an adhesive coating (33) that at least partially covers the threaded portion of the screw. The adhesive coating comprises a first zone (81) and a second zone (82) that are mutually adjacent, said first and second zones being respectively arranged on the first part (43) and on the second part (44) of the threaded portion of the screw.
The present invention concerns a fastener (110) for temporary assembling of at least two previously pierced structures (112), comprising: - a hollow body (122) comprising a support face (40); - elastic clamps (24) that can move with respect to the body and projecting relative to the support face; - a spacer (26) around which the elastic clamps are arranged; - a movable connecting element (130) extending inside the body and rigidly attached to the elastic clamps (24); and - an actuating element (132) connected to the connecting element by a thread/tapped hole (67, 84). The connecting element is crossed by a lateral orifice (70) extending axially between two closed ends (72, 74); and the fastener further comprises a transverse abutment (28) integral with the spacer, said abutment being able to slide between the axial ends of said lateral orifice.
The invention relates to a fastener for assembling at least two structural elements, comprising a aperture, the fastener comprising an enlarged head (12) and a shank (14) exhibiting, prior to fitting, an outside diameter (D ) greater than an inside diameter (D S ) of the aperture, and a locking portion comprising a screw thread or annular grooves. The fastener further comprises a lubricating sacrificial ring (40) on the exterior surface of the fastener, extending at least between a distal end of the shank and a proximal end of the locking portion, said ring having, before the fastener is fitted into the structure, an outside diameter greater than a diameter of the aperture. The sacrificial ring comprises a polymer resin forming a matrix encapsulating dispersant molecules and oil molecules. The invention applies to the assembly of aircraft structures.
The present invention concerns a nut (32) for assembling elements of a structure, said nut comprising: a collar (64) suitable for coming into contact with a front face of the structure; a clamping area having an external diameter (86) capable of being inserted into a hole of the structure; a deformation area adjacent to the clamping area and capable of forming a bulge against a rear face of the structure, opposite the front face; and a threaded portion (65) adjacent to the deformation area. The nut comprises grooving (82) on an outer circumference of at least part of the deformation area, a maximum diameter of said grooving (82) being smaller than or equal to the external diameter (86) of the clamping area.
The invention concerns a unit (210) for a locking device, comprising: a nut (212) comprising two coaxial taps in opposite directions; and a ring (213); said ring including a third tap (38); the first (18) and third (38) taps being capable of engaging with a single first thread (22); said ring including a second thread (40) capable of engaging with the second tap (20) of the nut. The unit further comprises a washer (214) configured (274) so as to be inserted around one (212) of the nut and the ring, the washer comprising an elastic engagement means (272) for engaging with the other (213) of the ring and the nut in an installation position of the unit, so as to prevent the ring and the nut from rotating relative to each other.
F16B 39/18 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down by means of locknuts in which the screw-thread of the locknut differs from that of the nut in which the locknut grips with screw-thread in the nuts as well as on the bolt
F16B 1/00 - Devices for securing together, or preventing relative movement between, constructional elements or machine parts
F16B 33/02 - Shape of thread; Special thread-forms
The invention relates to a locking device (300) comprising: a shaft (24) comprising a first thread (22); and a nut (12) and a ring (13) to be assembled on the shaft; the nut comprising a first inner thread (18) defining a first radial clearance with the first thread of the shaft; the nut further comprising a second inner thread (20) in the opposite direction to the first inner thread, the ring (13) comprising a second thread (40) defining a second radial clearance with the second inner thread of the nut; the ring comprising a third inner thread (38) defining a third radial clearance with the first thread of the shaft. The inner threads and the first and second threads have an identical and constant thread pitch; and each of the second and third radial clearances is greater than the first radial clearance.
F16B 39/18 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down by means of locknuts in which the screw-thread of the locknut differs from that of the nut in which the locknut grips with screw-thread in the nuts as well as on the bolt
F16B 1/00 - Devices for securing together, or preventing relative movement between, constructional elements or machine parts
F16B 33/02 - Shape of thread; Special thread-forms
The present invention relates to a unit (10) for a locking device, including: a nut (12) comprising first (18) and second (20) coaxial taps in opposite directions; and a ring (13); said ring including a third tap (38); the first (18) and third (38) taps being capable of engaging with a single first thread (22); said ring including a second thread (40) capable of engaging with the second tap (20) of the nut. A portion (33) of the ring, projecting relative to the second thread (40), includes a through-hole (60); and a surface (16) of the nut includes a visual marking, configured to be opposite the hole (60) when the nut and the ring are in an installation position, and separated from said hole when the nut and the ring are outside said installation position.
F16B 39/18 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down by means of locknuts in which the screw-thread of the locknut differs from that of the nut in which the locknut grips with screw-thread in the nuts as well as on the bolt
F16B 1/00 - Devices for securing together, or preventing relative movement between, constructional elements or machine parts
F16B 33/02 - Shape of thread; Special thread-forms
13.
FASTENING SOCKET FOR ASSEMBLING STRUCTURES AND ASSOCIATED ATTACHMENT
The present invention concerns a fastening socket (112) for assembling at least two previously drilled structures, said socket comprising a substantially cylindrical body (34) and an enlarged head (35); said enlarged head comprising first mounting surfaces (42, 46) suitable for being assembled to a first installation component and for preventing said first installation component from rotating about the main axis. The socket comprises a first substantially cylindrical recess (40) extending along the main axis from the first end, said first recess ending at a planar shoulder (44) substantially perpendicular to said main axis, the first recess and the planar shoulder being received inside the enlarged head, the first mounting surfaces (42, 46) being formed by an inner surface of the first recess.
B25B 13/48 - Spanners; Wrenches for special purposes
B25B 23/00 - TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING - Details of, or accessories for, spanners, wrenches, screwdrivers
The invention relates to a positive locking fastener comprising: - a screw (1) having a cavity (110) at a threaded portion (11); - a nut (2) having a tightening portion (21); - a first cap (3); - a second cap (4); and - a pin (5). The first cap is suitable for being inserted into the cavity of the threaded portion. The second cap has a locking portion (402) intended to engage with the first cap and a blocking portion (401) intended to engage with a tightening portion (21) of the nut. The locking portion of said second cap comprises openings (4020) suitable for allowing the pin to be inserted through said openings in order to hold the first cap and the second cap together. The invention also relates to a method for implementing the fastener according to the invention.
F16B 39/08 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down with a cap interacting with the nut, connected to the bolt by a pin or cotter-pin
The invention relates to a positive locking fastener comprising: - a screw (1) having a radial hole (120) at a threaded portion (12); - a nut (2) having a tightening portion (21); - a cap (3); and - a pin (4). The cap has a locking portion (31) intended to cover the threaded portion and an immobilising portion (30) intended to engage with a tightening portion of the nut. The locking portion comprises at least one pair of diametrically opposed openings (32) suitable for allowing a pair of openings to be aligned with the radial hole, in order to allow the pin to be inserted and thus lock the fastening regardless of the relative position of the nut with respect to the screw. The invention also relates to a method for implementing the fastener according to the invention.
F16B 39/08 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down with a cap interacting with the nut, connected to the bolt by a pin or cotter-pin
The invention relates to a positive locking fastener comprising: - a screw (1), a threaded portion (11) of which has a blind hole (110) and a groove (111); - a nut (2) having a tightening portion (21); - a cap (3); and - a pin (4). The cap (3) has an immobilising portion (31) intended to engage with the tightening portion (21) and a locking portion (32) intended to cooperate with the blind hole (110) to prevent said cap from rotating relative to the screw (1). The locking portion (32) also comprises openings (322) suitable for allowing the pin (4) to be inserted into said openings and into the groove (111) in order to hold the screw (1) and the cap (3) together.
F16B 39/08 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down with a cap interacting with the nut, connected to the bolt by a pin or cotter-pin
17.
LUBRICATING CAP, FASTENER COMPRISING THIS TYPE OF CAP AND INTERFERENCE ASSEMBLY PROCESS
The object of the invention is a cap to lubricate an inner wall of a perforation going through at least two elements of the structure. The cap comprises a tubular body and at least one lubricant reserve, and before installation in the structure said cap has a largest external diameter larger than an internal diameter (DS) of the perforation, and the cap lubricates the internal surface of the perforation when its largest external diameter is radially compressed by a wall of the perforation. The invention also concerns a fastener comprising this type of cap, and an interference assembly process for the fastener equipped with the cap. The invention is applicable to the assembly of aircraft structures.
The invention relates to a fastener (10) for assembling at least two structural elements, comprising a drilling, the fastener comprising an enlarged head (12) and a shank (14) exhibiting, prior to fitting, an outside diameter (Di) greater than an inside diameter (Ds) of the drilling, and a blocking portion comprising a screw thread or annular grooves. The fastener further comprises a lubricating sacrificial ring (20; 30) on the exterior surface of the fastener, extending at least between a distal end of the shank and a proximal end of the blocking portion, said ring having, before the fastener is fitted into the structure, an outside diameter greater than a diameter of the drilling. The invention applies to the assembly of aircraft structures.
The invention relates to a fitting rivet comprising: – a screw comprising a threaded portion (36), a sleeve (38) and a head (40); and - a bushing (32) comprising an essentially cylindrical body, said body comprising a deformation zone designed to form an external bulge (80); a collar (70) designed to receive the head of the screw; and a tapped portion (66) designed to engage with the threaded portion of the screw. The sleeve (38) of the screw comprises a first cylindrical portion (44) and a second cylindrical portion (46) that are connected by a shoulder (48), the first portion being adjacent to the head and having a first diameter, the second portion being adjacent to the threaded portion and having a second, smaller diameter.
The invention relates to an attachment for attaching structural elements having aligned bores having a nominal diameter (D), the attachment including a minimum tightening plane (Gmin) and a maximum tightening plane (Gmax), and a screw (12) including a widened head and a threaded portion (22), a sleeve (30) including a widened head, a cylindrical tubular body and a tapped portion (36) interlocking with the threaded portion (22) of the screw, the tapped portion (36) being adjacent to an inwardly smooth portion of the body (34) of the sleeve, said smooth portion having a thickness (E), a not easily deformable area (A) adjacent to the head of the sleeve and a deformable area (B) adjacent to the not easily deformable area (A), the deformable area (B) of the sleeve can deform to a bulb (48) intended to come into contact with a blind surface (46) of the structural elements. The deformable area (B) extends along a length (L) greater than a minimum length (Lmin) and less than a maximum length (Lmax), such that: Lmin = D/2 + 2E + (Gmax - Gmin), Lmax = (E/0.092). The invention applies in particular to the assembly of aircraft structures.
A clip nut 100 has first and second opposed arms 202, 204 extending longitudinally and the second arm 204 includes first and second walls 222, 224 extending transversely of the clip nut, and the first wall 222 includes a first plurality of cavities 234, 236 and the second wall 224 includes a second plurality of cavities 248, 250. A nut 102 includes legs 112, 114 extending into respective cavities. The nut is assembled with the clip nut by putting a leg into a cavity in the first wall and moving the nut toward the second arm to engage a cavity in the second wall.
The invention relates to a metallic fastener (10; 40) for assembly by interference fit of at least two structural elements (20, 22) comprising a through drilling, the fastener comprising an enlarged head (12; 42), a shaft (14; 44) having an external diameter (D1) before installation that is greater than an internal diameter (D3) of the bore, said shaft (14; 44) comprising a conductive surface (26; 56). Before installation, at least one conductive surface (26; 56) is covered with a lubricating layer (30) having sufficient adherence to prevent its abrasion by manual manipulation of the fastener (10; 40) and sufficiently weak to be at least partially torn from the conductive surface (26; 56) during mounting by interference fit of the fastener (10; 40), a mixture of at least one polyolefin and one polytetrafluoroethylene for example. The invention also relates to a method for obtaining such an fastener (10;40) and an installation method of such a fastener (10; 40) in a structure (22; 24). The invention has application in the assembly of aircraft structures.
The invention relates to an insert (10) including a first end (12) defining a circular opening (14), a cylindrical body (16) having an inner wall (18) and an outer wall, a second end (20) defining an opening (22) and forming a widened neck (24), characterised in that the body includes a first portion (28), adjacent to the first end, provided with an outer thread (30), and a second portion (32), adjacent to the first portion, including at least two cut-outs (34) defining at least two flexible tabs (36) extending axially, each tab having an outer thread (38) and forming an angle (a) with an axis (A) of the insert towards the outside of the body. Such an insert is used for axially positioning the outer rings of bearings.
The invention relates to a fastener (10) for the temporary joining of at least two pre-pierced structures, of the type comprising: - a body (11) that is liable to come into contact with a face of the structures to be joined, - a spacer (17) secured to said body, - two elastic half-grippers (15), each gripper being provided with a catching spur (16); - a mechanism that is movable with respect to the body, comprising a threaded rod (18) connected to the half-grippers and a drive nut (20) mounted on said rod, the drive nut comprising: - an internal thread (19) that engages with the thread (25) on the rod, - an external thread (26) that engages with an internal thread (28) on the body, the thread on the body and the thread on the drive nut being of opposite hand.
The invention relates to a cage nut device (10), comprising: - a nut (11) comprising a tubular body (12) connected to a collar (15), which is substantially planar and orthogonal to the body, - a nut support (20) comprising a nut cage (23) forming an internal housing (28) able to accommodate the nut, the support also comprising a tubular portion, with the result that the collar of the nut can be inserted into said internal housing, characterized in that an external surface of the tubular portion of the nut support comprises longitudinal splines (22) having a diameter less than the diameter of the bore, and at least two longitudinal ribs (44) having a diameter greater than the diameter of the bore. The invention also relates to a method for installing such a device.
The invention relates to a securing device (10) for a structure (11) provided with an open-ended cylindrical bore (13a), the securing device comprising: - an insert (15) comprising a tapped tubular body (16) and a head (18), the end (20) of the body that is opposite the head having an annular cavity holding a ring (21) made of plastics material; - a screw (22) comprising a cylindrical threaded shank (16) assembled with the thread of the insert and a head (23), the end (30) of the cylindrical threaded shank being frustoconical; the device being characterized in that the threaded shank is introduced into the insert on the ring side such that, in the assembled state, the head of the insert and the head of the screw form terminal ends of the securing device (10). The invention also relates to an assembly for the installation of such a device, and also to an installation method.
The invention concerns a metal attachment (10) for providing an electrically conductive surface through the entire thickness of structural elements to be assembled. The attachment therefore comprises a head (12) and a smooth barrel (14) extending along an axis of revolution, characterised in that the barrel comprises at least one conductive portion (24) and one lubricating portion (22) disposed along the axis of revolution of the attachment on at least one length of the barrel. The attachment according to the invention provides a conductive surface through the entire thickness of the structure in which it is installed. The attachment according to the invention is intended, in particular, for aeronautical applications.
The invention concerns a metal attachment for providing an electrically conductive surface through the entire thickness of structural elements to be assembled. The attachment therefore comprises a head (12) and a smooth barrel (12) extending along an axis of revolution, the barrel comprising at least one conductive portion (24) and one lubricating portion (22) disposed along the axis of revolution of the attachment on at least one length of the barrel. The attachment according to the invention provides a conductive surface through the entire thickness of the structure in which it is installed. The attachment according to the invention is intended, in particular, for aeronautical applications.
The invention relates to a tool (15) for applying fasteners, said tool comprising: - a sheath providing a cylindrical housing (18) with a polygonal base, - a roller cage (19), received in said cylindrical housing, said cage comprising: - a cylindrical support (33) with a substantially circular base, capable of pivoting inside the cylindrical housing - rollers (34) arranged on the rim of the support, each roller being rotatably mobile relative to said support, - a compression spring (36) exerting a radial force on the rollers in the direction of the main axis, the tool further comprising a return element (37) that urges the rollers of the cage towards the corners (27) of the cylindrical housing of the sheath.
The invention relates to an attachment bolt (10) including: a screw (11), said screw comprising a threaded portion (17) and an end portion (18) having a diameter (19) that is smaller than that of the threaded portion, an end surface (21) of said end portion, including a transverse through-groove (22); a nut (30) comprising a tapered body (32) and a non-tapered crown( 34) having at least two diametrically opposite holes (35) drilled therein; a pin (23) suitable for being inserted in the groove of the screw and in the two holes of the nut in order to lock the bolt; the tapered body of the nut comprises a driving portion (38) as well as a chimney (34) that is less thick than the driving portion; the nut results from a method including elliptically deforming the chimney from a circular shape.
F16B 39/04 - Locking of screws, bolts, or nuts in which the locking takes place after screwing down with a member penetrating the screw-threaded surface of at least one part, e.g. a pin, wedge, cotter-pin, screw
F16B 39/284 - Locking by means of elastic deformation
The invention relates to a lock (100) comprising: - two substantially planar walls (101) bearing a first pivot connection axle (102) and a second pivot connection axle (103), the first and second axles being substantially perpendicular to the planes; - a catch (108) able to pivot about the first axle, the catch comprising a hook (109) able to catch a strike wire; - a pawl (111) able to pivot about the second axle, the pawl comprising a tooth (112) able to engage with at least one notch (113, 14) formed on the catch, when the lock is in what is known as the closed position; - a control lever (115) able to pivot about the second axle, the lever comprising a means (116) of driving the rotation of the pawl (111) about the second axle, the control lever comprising means (118, 119) for securing the closure of the lock.
The invention concerns a braking ring nut, for example made from titanium alloy, and a method for producing such a nut. The nut comprises a body having a bearing face that is to rest on a structure, an outer drive surface of the nut to be driven by a tool, a through-hole comprising a thread on one portion of the height of the through-hole and a recess of which the internal diameter is greater than the diameter of the thread. A braking ring (32) is disposed inside the recess, and a crimping face (H1) opposite the bearing face is folded towards the axis of revolution of the nut in such a way as to hold the braking ring captive. The body of the nut comprises, around a portion of the recess, a collar having a concave radiated outer surface (H2) for the operation of folding the collar without cracking the material forming the nut.
The invention relates to a device (1; 20; 51) for assembling pre-bored (15) elements (2; 3), the elements together having a reference thickness (18) that may vary within a predetermined range (38) between an actual minimum thickness (39) and an actual maximum thickness (40), the device comprising a male element (4: 21; 52) extending along an axis (5; 23) and comprising a shank (6; 22; 54) that extends to a first end (8; 23; 55) in a head (7; 24; 56), and to a second end (9; 25; 57), via a shoulder (10; 26; 58), in a thread (11; 27) or in crimping grooves (59), an external surface (12; 28; 60) intended to be in contact with the boring having a height (13; 61) equal to a height (14) of the shank, chosen so as to correspond to at least one actual maximum thickness (40) of the elements to be assembled, and including a tightening range selected to be at least equal to the predetermined range (38), characterized in that the external surface has a visual reference mark (16; 35; 63) located at a distance (17) from a lower limit (9; 34; 57), or extending over a distance (17) from a lower limit to an upper limit (42A; 42B; 65) toward the head, said distance (17) corresponding to the maximum of the tightening range of the device.
The invention relates to a method for locking a nut (48) having an inner thread, wherein: a mechanical strength (Rm) to tensile failure and an elastic resistance (Re) of the material constituting the nut as a function of temperature are determined; an optimum heating temperature (7, 12) is determined, for which a maximum for a relative plastic interval of the material is reached, said relative range of plasticity being defined by the formula (Rm Re) / Rm; a maximum heating duration is determined, beyond which the nut risks deterioration in the initial microstructure thereof and/or in the initial mechanical strength thereof; the nut is heated at a temperature substantially equal to said optimum temperature at a heating duration of less than said maximum duration such that the initial microstructure and the initial mechanical strength of the material constituting the nut are preserved; and a body (47) of the nut is locally deformed by bending. Such a method makes it possible to easily change the shape of the nut, with no risk of springback or rupture in the material constituting the nut.
According to the prior art, there is a multiplicity of drilling and length families by fixation diameter recognition, contrarily to cylindrical smooth portion fixations for which a single tool is not sufficient. The person skilled in the art must plan the adequate tool and device for each thickness of a member to be clamped, which represents an important tool cost and also a time loss due to the change of tools. The purpose of the invention is to adapt the taper ratio (C1; C2) of the device (1, 20) based on the thickness to be clamped (12, 31). Preferably, the taper ratio of the bushings ranges between 1 and 4 %. Accordingly, using three to four reference sets of devices having the same outer diameter (16A, 16C) but a different taper ratio, it is possible to clamp any potential member thickness with modifying the bore diameter of members to be assembled.
The distribution of load stresses on the engaged threads of a standard screw or nut is not even. Indeed, the first engaged threads bear a large majority of the load. Consequently, if the load is too great, the threads break and the function is not provided anymore by the screw or nut. The prior art describes threads having a depth or a pitch that vary substantially in order to induce self-tightening. The aim of the invention is to optimise the mechanical resistance and fatigue resistance of the screws via a better distribution of the load on the threads thereof and without inducing said self-tightening. It has been demonstrated that the control of the pitch variation, within a predetermined pitch range, makes it possible to control the distribution of the stresses on the threads. It is possible to determine a different variation corresponding to each load case encountered.
It has become apparent that the dimensions of inbuilt-collar driving means of the same nominal size can vary according to the manufacturing process. The dimensions of the collar have to be adapted to suit the method of manufacture accordingly, at the expense of strength or mass. In addition, the torque that can be transmitted for tightening and loosening varies according to a useful height on which a wrench can gain a purchase. The idea underlying the invention, in order to have a useful height identical to the height of shank (7) is for the frustoconical collar (152) of a driving means (151) to be pushed in towards its centre in the continuation of the faces of the shank. The driving means with inbuilt collar proposed by the invention is suited to all methods of manufacture, and can be manufactured without adversely affecting the dimensions of the driving means or how it is fitted.
The invention relates to a reusable temporary fastening device (1), such as a pin clamp, for preassembling at least two structural members (4, 5) previously formed with coaxial bores (2, 3) for receiving said device, which comprises: a hollow cylindrical body (10) extending along an elongation axis (XX’); a bearing ring (20) provided at a proximal end (10a) of the hollow body (10) and against which one of the structural members (4, 5) is intended to bear in a fastening position of the device (1); a pulling threaded rod (40) extending through the hollow body (10) and coaxial thereto, and to be inserted into the respective coaxial bores (2, 3) of the structural members (4, 5) to be attached; a tightening means connected to the pulling threaded rod, for maintaining the structural members (4, 5) against each other, wherein the tightening means includes at least one removable tubular end piece (50) adapted to be mounted on a proximal threaded end (40a) of the pulling rod (40), and can be locally axially compacted under the action of a force applied on said pulling rod in order to form a radial bead (100) for sandwiching the structural members (4, 5) between the latter and the bearing ring (20); characterised in that the device comprises a sheath (30) having a bearing ledge (36) on which the tubular end piece (50) bears, and enabling the formation of a radial bead (100) at a distance from the structural members.
The invention relates to a riveting tack (50) to be introduced into coaxial openings of at least two elements to be assembled, and comprising a hollow cylindrical body (51), a rod (53) passing through the hollow body and partially provided with an external thread (52a), a bolt (54) mounted on the threaded end (53a), two half-clips (56) fixed to the rod (53) and comprising hooking lips (57) on the ends thereof, and a spacer (58) arranged between the two half-clips (56), the rod/half-clip set being axially mobile along the spacer (58) between a first position wherein the hooking lips (57) are radially close, and a second position wherein the two half-clips (56) are retracted inside the hollow body (51) and radially distanced from each other. The invention is characterised in that the set formed by the half-clips (56) and the spacer (58) is, in the cross-section thereof, in the form of a near-perfect circle having a diameter identical to the internal diameter of the openings.
patents
