Abstract: A blind fastener for clamping sheet components and including a mechanical lock to prevent loosening of the fastener. The fastener is self-expanding following insertion and engagement of the threaded stem. The fastener includes an internally threaded nut body, an externally threaded stem threadably received within the nut body, and a lock sleeve matingly receiving the nut body. Carried on the stem is an expandable sleeve which expands to engage the underside of the material. Rotation of the stem following insertion of the assembly into the aperture will draw the stem head and expandable sleeve against the backside for the material causing the sleeve to expand outwardly. In addition, the locking sleeve is pushed beneath the expansion sleeve wedging between the threaded stem and expansion sleeve. This mechanical lock is resistant to vibration locking the fastener against loosening.

Abstract: A blind fastener having a body, a core bolt, a nut and a sleeve. The core bolt passes through an axial bore of the body and includes an externally threaded portion at an inner end thereof. The nut has an enlarged head, a reduced diameter stem and a threaded bore for engaging the threaded portion of the core bolt. The sleeve is located between the enlarged head of the core bolt and a conically shaped inner portion of the body. An inner end portion of the sleeve is fixed to the stem of the nut. In a preferred embodiment, the inner end portion of the sleeve is crimped to the nut and has a thickness sufficient to engage the nut across the full width of an annular shoulder of the nut during setting of the fastener.

Abstract: A blind fastener having a body, a core bolt, a nut and a sleeve. The core bolt passes through an axial bore of the body and includes an externally threaded portion at an inner end thereof. The nut has an enlarged head, a reduced diameter stem and a threaded bore for engaging the threaded portion of the core bolt. The sleeve is located between the enlarged head of the core bolt and a conically shaped inner portion of the body. An inner end portion of the sleeve is fixed to the stem of the nut. In a preferred embodiment, the inner end portion of the sleeve is crimped to the nut and has a thickness sufficient to engage the nut across the full width of an annular shoulder of the nut during setting of the 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: An insert assembly for installation in a workpiece having a threaded hole. When the inner insert is axially received within the outer insert, the mating surfaces of these members are configured such that the inner insert applies a radial outward force to the outer insert to securely install the insert assembly in the workpiece. A stud assembly also is provided for installation in the workpiece hole. The stud assembly comprises a stud body and a stud. When the stud is axially received within the stud body, the mating surfaces of these members, like the insert assembly, are configured such that the stud applies a radial outward force to the stud body to securely install the stud assembly in the workpiece. Both the insert assembly and stud assembly are particularly adapted for use with workpieces made of relatively soft or lightweight materials.

Abstract: A blind fastener for fastening panels, especially panels made of composite materials, comprises a fastener body received within aligned openings in the panels and a cylindrical stem passing through the fastener body. The stem has an enlarged stem head spaced from an inner end of the fastener body which projects inwardly beyond the inner surface of the inner panel. A deformable sleeve mounted on the stem between the stem head and the inner end of the fastener body is a two-piece sleeve comprising a forming sleeve and a containment sleeve. The forming sleeve is made of a relatively soft, deformable material, whereas the containment sleeve is made of a relatively hard, nondeformable material. When the stem moves outwardly through the fastener body during setting of the fastener, the forming sleeve deforms to a fully set condition in overlying contact with the inner surface of the inner panel, forming a large bearing area that does not damage the composite material of the panels.

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 fastener having an internally threaded nut body, an externally threaded stem and a lock collar keyed to the nut body. The lock collar has a plurality of spring arms extending radially at an angle into the internally threaded bore of the nut body. During setting of the fastener, the stem is rotated in a tightening direction relative to the nut body. However, when the fastener is fully set, the spring arms will engage axial grooves in the stem to prevent relative rotation in a loosening direction between the nut body and the stem. This configuration forms a positive mechanical lock between the stem and the nut body and prevents the fastener from loosening and losing its clamping force, even when the fastener is subjected to high levels of stress and vibration.

Abstract: A fastener and method for fastening panels is disclosed. The fastener comprises a bolt and a nut with a locking feature to prevent loosening of the fastener from vibration after it has been set. The locking feature comprises a frustoconical tip on the inserted end of the bolt that engages a retainer ring in the nut. When setting the fastener, the retainer ring deforms around the outer end of the tip and slides down the narrowing frustoconical surface of the tip until the fastener is fully set. Unthreading of the bolt from the nut is prevented since the retainer ring will resist deformation along the increasingly larger diameter portions of the frustoconical tip. In another aspect of the invention, the nut is provided with shear tabs which engage a wrenching tool. These tabs are designed to shear when the fastener is fully set to prevent further application of torque by the tool.

Abstract: A sleeve bolt for coupling together workpieces including a cylindrical sleeve having a cylindrical outer surface and an axial bore with a radially interior surface of polygonal configuration at one end and internal threads at the other end. An inner slide member with a polygonally shaped cross-sectional configuration positioned within the bore at the polygonally configured end for movement between a retracted orientation totally within the cylindrical sleeve and a protruding orientation partially withdrawn from the cylindrical sleeve. A coupling connects the inner slide member for sliding movement along the longitudinal axis of the sleeve between the retracted and protruding orientation and includes stop means connected to the sleeve for defining the limits of movement of the slide member between retracted and protruding orientations.

Abstract: A method of forming a lightweight threaded fastener element of bimaterial construction to high tolerance requirements, the element formed by the steps of shaping a metal shell to a preliminary configuration blank by extrusion, filling the extruded shell with a less dense material such as a curable epoxy-graphite material or an aluminum-lithium alloy, further shaping the filled blank by forging both the core material and shell to an intermediate configuration which is finished by warm rolling to form a strong lightweight fastener element configured with the metal shell thereof which may be engageable with a cooperating metal fastener assembly member.

Abstract: A driver has a deltoid wrenching and deforming socket in the form of an equilateral triangle with rounded corners. Flats of the socket between the apexes of the triangle bear on lobes of a collar to thread the collar onto a pin in the making of a joint. At a predetermined clamp-up load on the joint, the flats of the deltoid socket crush the lobes plastically and force material of the collar radially inward of the lobes into locking engagement with the pin. Thereafter the socket can rotate freely on the collar. A pilot section of the deltoid socket cooperates with a corresponding section of the collar to keep the driver from canting off axis. Reliefs with cylindrical surfaces in the sides of extensions of the flats define piloting surfaces of the pilot section.

Abstract: A threaded pin has flutes along the threads formed by roll-forming threads over a preformed section having either flat sides or dished sides. The major diameter of the threads lies along ridge crests bordering the flutes, and the minor diameter of the threads lies at the base of the flutes. The threads extend along the major diameter in each of the ridge crests for a distance on an order of magnitude of the distance across the mouth of each flute. The preformed section is formed by extrusion. The flutes provide space for material from a threaded collar forced into them to provide a thread lock.

Abstract: A collar threads onto a shear pin. When the collar engages a surface of a workpiece, resistance to further threading increases. When sufficient resistance to threading occurs, a setting driver upsets lobes of the collar and forces these lobes radially inward toward the axis of the collar. Material of the collar inside the lobes responds to deformation of the lobes and flows radially inward against the shear pin to lock the collar, shear pin and workpiece together. The driver then rotates freely and a joint has been made with a predetermined clamp-up load and its component parts locked together.

Abstract: A collar threads onto a shear pin. When the collar engages a surface of a workpiece, resistance to further threading increases. When sufficient resistance to threading occurs, a setting driver upsets lobes of the collar and forces these lobes radially inward toward the axis of the collar. Material of the collar inside the lobes responds to deformation of the lobes and flows radially inward against the shear pin to lock the collar, shear pin and workpiece together. The driver then rotates freely and a joint has been made with a predetermined clamp-up load and its component parts locked together.

Abstract: A blind fastener has a nut with a threaded bore, a core bolt having external threads for receipt by the nut, and a sleeve for expansion by the head of the core bolt and a shoulder of the nut to form a blind side folded bulb against the backside sheet of a joint. A thin-walled, tapered section of the sleeve fits over a relieved section of the nut and bears against the shoulder of the nut. The taper is such that the thin wall increases in thickness away from the shoulder. An axially adjacent thick-walled section of the sleeve bears on the core bolt head and resists sleeve tuck-out over the core bolt head, concentrically aligns the sleeve on the core bolt, and assures that the thin-walled section of the sleeve is the section that bulbs. During setting, the sleeve expands by compression exerted on it by the core bolt head and the shoulder. The thin wall section folds against the backside sheet with an ever-increasing area as tightening continues.

Abstract: A mechanically locking fastener has external threads for installation in the threaded bore of a workpiece. A lock ring has internal radial serrations locked in serrations of the fastener proper, and external radial teeth of a form for gripping the wall of the workpiece bore when turning moments tend to loosen the fastener and to pass over the bore wall upon rotation in the opposite direction. The lock ring has a slip plane to permit contraction of the ring to a diameter no greater than the major diameter of the fastener and expansion of the ring when the fastener undergoes moments tending to loosen it. The fastener proper may be a stud or an insert. An external chamfer of the ring bears against a cooperating internal surface of the workpiece to positively determine the axial location of the insert with respect to the workpiece.

Abstract: A blind fastener system comprising a ductile sleeve having an expansion portion of small inner diameter in a thin workpiece and having a bulbing portion of larger inner diameter extending on the blind side of the workpiece, and a threaded expander member having an expander portion for expanding the sleeve expansion portion and a head portion for bulbously deforming the sleeve bulbing portion, both actions occurring on axially pulling the expander member. The expander portion has a tapered, radiused leading end followed by a configured (splined, knurled, etc.) portion for the remainder of the active length. The protrusions of the configured portion leave a void volume between them and between the minor and major diameters of the protrusions, and the volume of the sleeve expansion portion between the small inner diameter and the projection of the large inner diameter is approximately 0.5 to 0.8 of the void volume of the configured portion. The protrusions have blunt outer surfaces.