Two-piece blind fasteners and installation tools

Abstract

The blind fastener (10) includes a bolt (14) and a nut (18). The bolt includes a shaft (110), a bolt head (114), and a lug (118). The bolt head is between the shaft and the lug and extends radially outward from the shaft. The shaft defines external threads (126) on an opposite side of the bolt head. The lug includes a first tool-engaging portion (1509) and a first frangible portion (174) that frangibly couples the lug to the bolt head. The nut includes a sleeve (210), a nut head (214), and a handling member (218). The nut head extends radially outward from the sleeve and defines a recess (242) that receives the bolt head. The handling member surrounds at least a portion of the lug. The handling member includes a second frangible portion (270) and a second tool-engaging portion (266). The second frangible portion frangibly couples the second tool engaging portion to the nut head.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 891,678, filed August 26, 2019, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates generally to fasteners, and more particularly to a blind fastener for connecting panels from one side of the panels, having a core bolt and a nut around the core bolt. [Background technology]

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] Blind fasteners are commonly used to secure multiple panels together and to attach from one side (i.e., the front) of the panels. A blind fastener may include a core bolt and a sleeve that surrounds the core bolt and is inserted into a hole in the panel. A portion of the sleeve adjacent the back side of the panel may deform during installation of the fastener. The deformed portion of the sleeve provides a bearing surface to induce a preload on the fastener so that the panels can be clamped together.

[0005] After the deformed portion of the sleeve is formed, the core bolt can be rotated to provide preload to the fastener. Once the fastener is fully installed, the front of the core bolt may break off. The break point of a typical core bolt cannot be controlled, and typically requires controlled rotation of the nut relative to the bolt. For aesthetic and aerodynamic reasons, it can be advantageous for the fully installed fastener to be flush with the panel. If the break point is located outside the countersunk head of the sleeve, the typical fastener must be polished after installation to be flush with the panel and ready for painting.

[0006] Controlling the rotation of both the bolt and nut while ensuring a flat finish, maximizing installation speed, and reducing cost per fastener can be challenging. Also, variations in grip length (i.e., the total thickness of the panel at the fastener) can occur based on tolerances or design criteria. Therefore, it is advantageous for blind fasteners to be able to accommodate variations in grip length without sacrificing joint strength. Additionally, typical fasteners do not include torque control features. When excessive torque is applied to a fastener, the sleeve of the fastener flares, forming a tulip configuration, resulting in installation defects. These problems associated with installing blind fasteners are addressed by the present disclosure. Summary of the Invention

[0007] In one embodiment, a blind fastener for connecting multiple workpieces includes a bolt and a nut. The bolt includes a shaft, a bolt head, and a lug. The bolt head is disposed between the shaft and the lug and extends radially outward from the shaft. An end of the shaft opposite the bolt head defines external threads. The lug includes a first tool-engaging portion and a first frangible portion frangibly coupling the lug to the bolt head. The nut includes a sleeve, a nut head, and a handling member. The sleeve includes a central bore configured to receive the shaft and defines internal threads configured to mate with the external threads. The nut head is disposed between the handling member and the sleeve. The nut head extends radially outward from the sleeve and defines a recess configured to receive the bolt head. The handling member is configured to surround at least a portion of the lug. The handling member includes a second frangible portion and a second tool-engaging portion. The second frangible portion frangibly couples the second tool engaging portion to the nut head.In various alternatives, the end face of the bolt head is flush with or recessed from the end face of the nut head when the bolt is fully threaded onto the nut, the first frangible portion is configured to break away from the bolt head such that the end face of the bolt head is flush with or recessed from the front faces of the plurality of workpieces, the second frangible portion is configured to break away from the nut head such that the end face of the nut head is flush with or recessed from the front faces of the plurality of workpieces, the first tool engaging portion includes a lead-in ramp, the second tool engaging portion includes a lead-in ramp, the second frangible portion is entirely radially inward of an outermost periphery of the nut head, the handling member defines a bore having a diameter equal to an outermost diameter of the recess, the lug includes a retaining lip, and the handling member has a diameter less than the diameter of the retaining lip. The blind fastener defines a bore, the retaining lip extends radially outward from the first tool engaging portion, the handling member is entirely radially outward from the first tool engaging portion, the blind fastener is comprised of two pieces when in a pre-installed state, the bolt is the first piece of the two pieces and the nut is the second piece of the two pieces, the second weakened portion defines a breakneck extending around the entire periphery of the nut, the first weakened portion defines a breakneck extending around the entire periphery of the bolt, when the blind fastener is in a pre-installed state the sleeve includes a ductile region having a hardness lower than that of the nut head, a portion of the sleeve between the ductile region and the nut head, and a portion of the sleeve at the female threads, when the blind fastener is in a pre-installed state the sleeve includes a variable annealed region having a hardness lower than that of the nut head and lower than the hardness of the portion including the female threads.

[0008] According to another aspect, a tool for installing a blind fastener including a bolt and a nut includes a drive member, a collet, and a nosepiece. The collet is driven by the drive member to engage the bolt. The nosepiece retains the nut and prevents the nut from rotating during installation of the blind fastener. The nosepiece is movable between a first position in which the nosepiece is driven by the collet and rotates with the collet, and a second position in which the nosepiece remains rotationally stationary despite rotational movement of the collet. According to various alternative embodiments, the tool further includes a retaining sleeve and a follower, the retaining sleeve being disposed around the nosepiece and defining a cam, the follower being disposed between the retaining sleeve and the nosepiece such that rotation of the nosepiece relative to the retaining sleeve causes the cam to move the follower radially inward toward the tool engagement portion of the nut, the tool further including an ejector pin and a spring that biases the ejector pin toward an extended position relative to the collet, the tool further including a plurality of stationary lugs, the nosepiece including a plurality of rotating lugs configured to engage with the stationary lugs when the collet is in the second position, each of the stationary lugs including an inclined surface, and each of the rotating lugs including an inclined surface.

[0009] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0010] In order that the present disclosure may be properly understood, various aspects of the disclosure will now be described, given by way of example only, with reference to the accompanying drawings. [Figure 1] FIG. 1 is an exploded rear perspective view of a blind fastener in accordance with the teachings of the present disclosure. [Figure 2] FIG. 2 is an exploded front perspective view of the blind fastener of FIG. 1. [Figure 3] 2 is a cross-sectional view of the blind fastener of FIG. 1 showing the blind fastener in a pre-installed position relative to a set of workpieces. [Figure 4] 2 is an enlarged cross-sectional detail view of a portion of the blind fastener of FIG. 1 in a pre-installed position. [Figure 5] 2 is a cross-sectional view of the blind fastener of FIG. 1 in an installed position showing the blind fastener installed relative to a set of workpieces. [Figure 6] FIG. 6 is a perspective view of the blind fastener of FIG. 5 showing a set of workpieces partially cut away. [Figure 7] FIG. 7 is a top view of the blind fastener of FIG. 6. [Figure 8] FIG. 1 is a perspective view of a tool for installing blind fasteners in accordance with the teachings of the present disclosure. [Figure 9] FIG. 9 is an exploded perspective view of the nose of the tool of FIG. 8. [Figure 10] FIG. 9 is a cross-sectional view of the nose of the tool of FIG. 8. [Figure 11] 9 is a perspective view of a collet and a portion of the nosepiece of the tool of FIG. 8, showing a cross section of a portion of the nosepiece. [Figure 12] FIG. 9 is a perspective view of a clutch of the tool of FIG. 8. [Figure 13] FIG. 9 is a front view of the nose of the tool of FIG. 8, showing the tool in a resting state. [Figure 14] FIG. 12 is a front view similar to FIG. 11, showing the tool in an operational state. [Figure 15] 9 is a perspective partial cross-sectional view of the nose of the tool of FIG. 8 in an operational state. [Figure 16] Figure 9 is a perspective view of the nose of the tool of Figure 8 in a resting state.The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0012] Fastener Assembly 1 and 2 , blind fastener 10 includes bolt 14 and nut 18 configured to mate with one another when coaxially disposed along central axis 22. In the example provided, bolt 14 is a single, integral piece of material, and nut 18 is another single, integral piece of material. Bolt 14 and nut 18 may be formed from any suitable type of material, such as, for example, a metal or alloy material. Bolt 14 may be formed from the same material as nut 18, or may be formed from a different suitable material. Blind fastener 10 may be similar to the blind fastener of U.S. Patent Application No. 16 / 201,775 (U.S. Patent Publication No. 2019 / 0162217), the disclosure of which is incorporated herein by reference in its entirety, except as specifically shown or described herein.

[0013] With further reference to FIG. 3 , the blind fastener 10 secures a first workpiece 26 to a second workpiece 30. In alternative forms not specifically shown, more than two workpieces may be secured together by the blind fastener 10. In the example provided, the workpieces 26, 30 are plates or panels formed of any suitable material, such as metal (e.g., aluminum), carbon fiber composite, or other suitable material for a given application. The first workpiece 26 has a first front surface 34 and a first back surface 38. The second workpiece 30 may be of a similar or different material to the first workpiece 26. Optionally, a suitable sealant or barrier (not shown) may be applied between the workpieces 26, 30 and / or between the workpieces 26, 30 and the blind fastener 10 to inhibit galvanic corrosion. The second workpiece 30 includes a second front surface 42 and a second back surface 46. The second front surface 42 faces the first back surface 32 .

[0014] The first workpiece 26 and the second workpiece 30 each define an opening that, when aligned, cooperates to form an opening 50 through the first front surface 34 and the second back surface 46 that is coaxial with the axis 22. The opening 50 may be countersunk or countersunk from the first front surface 34. In the example provided, the opening 50 is countersunk to include a cylindrical inner bore 54 and a contact surface 58 that extends axially obliquely between the inner bore 54 and the first front surface 34.

[0015] The bolt 14 is formed from a single, integral piece of material and includes a shaft 110, a bolt head 114, and a lug 118 that are disposed about an axis 22. The shaft 110 is generally cylindrical and includes a stem 122 and a threaded portion that defines external threads 126. The external threads 126 originate at one end 130 of the bolt 14. The stem 122 is disposed axially between the threads 126 and the bolt head 114.

[0016] In one form, the stem 122 has a generally smooth, cylindrical first outer surface 134 having a diameter equal to or greater than the outer diameter of the external threads 126. The external threads 126 extend axially along the axis 110 to a terminus adjacent the stem 122, although other configurations may be used. In one alternative not shown, a sealant or seal may be provided between the terminus of the external threads 126 and the stem 122 or along the stem 122 to seal against the inner surface of the nut 18. The seal (not shown) is configured to prevent the passage of fluids, such as, for example, water, oil, or fuel. The seal (not shown) may be, for example, an elastomeric body such as an O-ring.

[0017] The bolt head 114 is located at the end of the stem 122 opposite the external threads 126. The bolt head 114 extends radially outward from a first outer surface 134 of the stem 122.

[0018] 4, the bolt head 114 includes a clamping surface 138, a radially outermost portion 142, and a first end face 146. The clamping surface 138 extends obliquely radially outward from the first outer surface 134, although other configurations may be used. The outer periphery 142 extends axially between the clamping surface 138 and the first end face 146. In the example provided, the outer periphery 142 is generally parallel to the axis 22, although other configurations may be used. The first end face 146 faces axially away from the stem 122. In the example provided, the first end face 146 is generally perpendicular to the axis 22, although other configurations may be used.

[0019] 1 and 2 , the lug 118 includes a first tool engaging portion 150 and a first weakened portion 154. In the example provided, the lug 118 may also include a rim or retaining lip 158 axially between the first tool engaging portion 150 and the first weakened portion 154. The first tool engaging portion 150 defines the other end 162 of the bolt 14 opposite the external threads 126.

[0020] 3 , the first tool engaging portion 150 is configured to be engaged by a tool 310 to apply torque about the axis 22. In the example provided, the tool engaging portion 150 has a plurality of outwardly facing flat surfaces 156 forming a generally hexagonal shape, and the tool 310 includes a first socket 314 having a plurality of inwardly facing flat surfaces configured to engage with the first tool engaging portion 150, although other shapes or configurations may be used, such as, for example, star, spline, or lobe shapes or other drive configurations. In an alternative form not shown, the first tool engaging portion 150 may have a female tool engaging feature, such as, for example, a recessed socket, and the tool 310 may have a mating male feature, such as, for example, a male protruding socket.

[0021] 1 and 2, the tool engaging portion 150 may also optionally include angled lead-in ramps 152 that may guide the first socket 314 (FIG. 3) onto the tool engaging portion 150. Each lead-in ramp 152 originates at the distal end 162 of the bolt 14 and traverses a portion of the adjacent flat surface 156 (e.g., a portion of each corner of the hexagon). In the example provided, the external threads 126 of the bolt 14 are right-handed, and when viewed from the distal end 162, the lead-in ramp 152 may traverse the adjacent flat surface 156 in a clockwise direction and run diagonally or helically until it blends into the hexagon.

[0022] The retaining lip 158 is axially between the first tool engaging portion 150 and the first weakened portion 154 and extends radially outward from the first tool engaging portion 150. In the example provided, the retaining lip 158 has a generally frustoconical shape that widens with increasing distance from the first tool engaging portion 150.

[0023] 4, the circumference of the retaining lip 158 is greater than the diameter of the outer surface 166 of the first weakened portion 154, such that the retaining lip 158 and the outer surface 166 of the first weakened portion 154 form a shoulder 170. The retaining lip 158 may limit axial movement of a tool 310 (FIG. 3) toward the bolt head 114.

[0024] The first weakened portion 154 frangibly couples the retaining lip 158 to the bolt head 114. In the example provided, the outer surface 166 of the first weakened portion 154 is generally cylindrical in shape and has a diameter equal to or less than the outermost diameter of the outer periphery 142 of the bolt head 114. The first weakened portion 154 narrows from the outer surface 166 to a break neck 174 that joins the first end face 146 of the bolt head 114 to the lug 118. In the example provided, the diameter of the break neck 174 is smaller than the diameter of the first end face 134 of the stem 122 and extends the entire circumference of the bolt 14.

[0025] 1 and 2, the nut 18 in the provided example is formed from a single, integral piece of material and includes a sleeve 210, a nut head 214, and a handling member 218 disposed about an axis 22. The sleeve 210 is a generally cylindrical body having a second outer surface 226. One end of the sleeve 210 defines a terminal end 222 of the nut opposite the nut head 214. The sleeve 210 is received within an inner bore 54 (FIG. 3) of the first and second workpieces 26, 30 (FIG. 3).

[0026] The sleeve 210 defines a central bore 230 coaxial with the shaft 22 and includes internal threads 234. Referring to FIG. 3 , the internal threads 234 originate at the distal end 222 and extend axially toward the nut head 214, but terminate a predetermined distance from the second back surface 46. The internal threads 234 are configured to threadably engage the external threads 126 with the bolt 14. The first bore 230 has a diameter slightly larger than the diameter of the first outer surface 134 of the stem 122 so that the shaft 110 can be rotatably received within the first bore 230.

[0027] 1 and 2, sleeve 210 may also include one or more dimples 228 recessed radially inward from second outer surface 226. Dimples 228 may be proximate end portion 222 and equally spaced circumferentially about sleeve 210. Dimples 228 protrude slightly into first central bore 230, thereby extending radially inward of the outer diameter of internal threads 234 and providing an interference fit with external threads 126. Thus, dimples 228 may provide a low resistance to rotation between internal and external threads 234, 126.

[0028] 3, the sleeve 210 may include a ductile region 238 between the internal threads 234 and the nut head 214. The ductile region has a hardness that is less than the hardness of the remainder of the nut 18. In one form, the nut head 214, the region of the sleeve 210 surrounded by the first and second workpieces 26, 30, and the region of the sleeve 210 including the internal threads 234 may have a first hardness value, and the ductile region 238 may have a significantly lower hardness value. This significantly lower hardness value may be achieved, for example, by band annealing the sleeve 210.

[0029] Nut head 214 is located at the end of sleeve 210 opposite internal threads 234 and extends radially outward from sleeve 210. Referring to FIG. 4 , nut head 214 includes a recess 242, a clamping surface 246, and a second end face 250. Clamping surface 246 extends radially outward at an angle from second outer surface 226 of sleeve 210, although other configurations may be used. A perimeter 254 of nut head 214 is defined by the junction of clamping surface 246 and second end face 250. Second end face 250 may face axially away from sleeve 210 and be generally perpendicular to axis 22, although other configurations may be used.

[0030] One end of the recess 242 opens through the second end face 250, and the other end of the recess 242 opens to the first bore 230. The recess 242 is disposed coaxially with the axis 22 and configured to receive the bolt head 114. The recess 242 has an inner wall surface 258 and a contact surface 262. The contact surface 262 extends obliquely radially outward from the first bore 230 to the inner wall surface 258. In the example provided, the inner wall surface 258 is generally cylindrical and extends axially between the contact surface 262 and the handling member 218. The inner wall surface 258 has a diameter larger than the diameter of the periphery 142 of the bolt head 114, so that the bolt head 114 is rotatably received within the recess 242.

[0031] The contact surface 262 of the nut head 214 has an angle similar to the angle of the clamping surface 138 of the bolt head 114. The inner wall surface 258 of the nut head 214 abuts the contact surface 262 at a depth from the second end face 250 of the nut head 214 such that, when the bolt head 114 is received within the recess 242, the first end face 146 of the bolt head 114 is flush with or recessed from the second end face 250 of the nut head 214.

[0032] The handling member 218 includes a second tool-engaging portion 266 and a second weakened portion 270 disposed about the axis 22. The handling member 218 is coaxial with the axis 22 and defines a second bore 274 that opens through an end portion 278 of the nut 18 and into the recess 242. The second bore 274 surrounds at least a portion of the first weakened portion 154. In the example provided, the second bore 274 has a diameter smaller than the diameter of the retaining lip 158 of the lug 118, although other configurations may be used. In the example provided, the second bore 274 has the same diameter as the inner wall surface 258 of the nut head 214, such that the second bore 274 and the inner wall surface 258 may be formed as a single bore.

[0033] The second tool engaging portion 266 is configured to be engaged by a tool 310 (FIG. 3) to apply torque to the shaft 22. In the example provided, the second tool engaging portion 266 has a plurality of outwardly facing flat surfaces 264 forming a hexagon, and the tool (FIG. 3) 310 includes a second socket 330 having a plurality of inwardly facing flat surfaces configured to engage with the hexagon of the second tool engaging portion 266, although other shapes or configurations may be used, such as, for example, a star, spline, or lobe shape or other drive configuration. In the example provided, the second tool engaging portion 266 is entirely radially inward of the periphery 254 of the nut head 214.

[0034] 1 and 2, the second tool engaging portion 266 may also optionally include angled lead-in ramps 272 that may guide a second socket 330 (FIG. 3) onto the second tool engaging portion 266. Each lead-in ramp 272 originates at a terminal end 278 of the nut 18 and traverses a portion of the adjacent flat surface 264 (e.g., a portion of each corner of the hexagon). In the example provided, when viewed from the terminal end 278, the lead-in ramp 272 may traverse the adjacent flat surface 264 in a clockwise direction and run diagonally or spirally until it blends into the hexagon.

[0035] 4 , the second weakened portion 270 weakenably couples the second tool engaging portion 266 to the nut head 214. In the example provided, the inner surface of the second weakened portion 270 is defined by the second bore 274, and the outer surface of the second weakened portion 270 narrows from the second tool engaging portion 266 to define a breakneck 276. Thus, the handling member 218 has a minimum wall thickness around the axis 22 where the second weakened portion 270 meets the nut head 214. In the example provided, the breakneck 276 extends around the entire circumference of the nut 18.

[0036] In an alternative embodiment, the handling member 218 may be a component formed separately from the rest of the nut 18 (i.e., the sleeve 210 and the nut head 214). In an alternative embodiment, the handling member 218 may be attached to the nut head 214 by, for example, glue, adhesive, welding, or brazing. In this alternative, the weakened portion 270 is formed by glue, adhesive, welding, or brazing. This alternative may or may not narrow to a neck (similar to a breakneck 276) at the weakened portion 270, depending on the strength of the glue, adhesive, weld, or braze.

[0037] Installation 3 and 4, the bolt 14 and nut 18 are shown in a pre-installed position relative to one another. As shown in Figures 3 and 4, when the blind fastener 10 is in the pre-installed position and extends through the first and second workpieces 26, 30, the second end face 250 of the nut head 214 is flush with or recessed from the first front face 34. Because the sleeve 210 has an axial length that is longer than the maximum gripping length of the first and second workpieces 26, 30, the sleeve 210 is received through the opening 50 and extends from the second back face 46.

[0038] In this position, the first socket 314 of the tool 310 may mate and engage with the first tool engagement portion 150, and the second socket 330 of the tool 310 may mate and engage with the second tool engagement portion 266. The tool 310 then operates in a first mode, with the first socket 314 transmitting torque to the bolt 14 in the tightening direction of the threads 126, 234, and the second socket 330 holding the nut 18 rotatably stationary relative to the workpieces 26, 30. The tool 310 prevents the bolt 14 and nut 18 from axially separating from the workpieces 26, 30.

[0039] 3 and with further reference to FIG. 5, the screws 126, 234 apply an axial force to the sleeve 210 to move the distal end 222 of the sleeve 210 toward the workpieces 26, 30, causing the ductile region 238 of the sleeve 210 to deform radially outward to form the valve 510. The valve 510 may contact the second back surface 46 and apply a force to the second back surface 46 that urges the second workpiece 30 toward the first workpiece 26. Thus, the first and second workpieces 26, 30 are clamped between the nut head 214 and the valve 510.

[0040] Once the valve 510 is formed, the valve 510 and sleeve 210 can withstand further deformation. Subsequent application of additional torque to the bolt 14, exceeding a predetermined torque threshold, can fracture the first weakened portion 154. Specifically, the lug 118 rotates in the tightening direction, while the nut 18 is rotatably held and axially stationary. The threads 126, 234 apply an axial force to the sleeve 210 until the shear strength of the breakneck 174 is exceeded. The breakneck 174 then shears, separating the lug 118 from the bolt head 114. The shearing of the breakneck 174 leaves the first end face 146 of the bolt head 114 flush with or slightly recessed from the second end face 250 of the nut head 214, as shown in FIG. 5 .

[0041] The clamping force of the valve 510 and nut head 214 against the workpieces 26, 30 can withstand rotation of the nut 18 relative to the workpieces 26, 30. The second socket 330 then applies a torque to the handling member 218 that exceeds a predetermined torque threshold to break the second weakened portion 270. Specifically, the second weakened portion 270 shears at the breakneck 276, separating the handling member 218 from the nut head 214. The shearing of the second weakened portion 270 leaves the second end face 250 of the nut head 214 flush with or slightly recessed from the first front face 34 of the first workpiece 26, as shown in FIG. 5 . In the example provided, the retaining lip 158 has a larger diameter than the second bore 274, so the lug 118 cannot drop axially through the second bore 274. Thus, the lug 118 can be removed together with the second handling member 218 .

[0042] Thus, as shown in Figures 6 and 7, the blind fastener 10 is easy to install without requiring additional machining or processing, and is flush with the first workpiece 26 when in the fully installed position.

[0043] tool Referring to FIG. 8 , a tool 810 for installing a blind fastener, such as blind fastener 10 (FIGS. 1-7), is shown. Tool 810 and its operation may be similar to the tool of co-pending and commonly owned U.S. Patent Application No. 16 / 203,535 (U.S. Patent Publication No. 2019 / 0160520), the entire disclosure of which is incorporated herein by reference, except as specifically shown or described herein. Tool 810 includes a nose 814 and a driver 818 drivingly coupled to nose 814. In the example provided, driver 818 is a powered handheld nutrunner. In alternative configurations not shown, driver 818 may be any suitable type of drive mechanism configured to drive nose 814, such as, for example, a pneumatic drive mechanism or an end effector of a robotic arm.

[0044] 9 and 10 , driver 818 includes a gearbox 822 and a drive shaft 826. Gearbox 822 receives input torque from a motor (not specifically shown) of driver 818 and outputs torque to drive shaft 826, causing drive shaft 826 to rotate about axis 830. Nose 814 includes a clutch 834, a first spring 838, a second spring 842, an ejector pin 846, a retaining sleeve 850, a nosepiece 854, and a collet 858. Collet 858 is coaxial with axis 830 and is coupled to drive shaft 826 for common rotation. In the example provided, collet 858 is coupled to drive shaft 826 by a set of mating threads 862.

[0045] 10 , the collet 858 defines a spring chamber 866, a stop 870, a first socket 874 (e.g., first socket 314 in FIG. 3 ), and a nut 878. The first socket 874 may have an internal shape configured to mate with the tool engagement portion 150 of the bolt 14. The ejector pin 846 has a shaft 882 and a head 886 and is coaxial with the axis 830. The shaft 882 is configured to extend axially between the first socket 874 and the spring chamber 866 through an opening 890 defined by the stop 870. The head 886 is slidably received within the spring chamber 866 and has a diameter larger than the opening 890. The second spring 842 is disposed within the spring chamber 866 and configured to bias the ejector pin 846 toward a forward position in which the head 886 abuts the stop 870.

[0046] Referring to FIG. 11 , the nut 878 of the collet 858 is generally hexagonal, although other configurations may be used. In the example provided, the nut 878 includes angled or spiral lead-in ramps 910 that angle downward from the rear of each hexagonal point toward the cylindrical surface. The lead-in ramps 910 may also be angled axially. In other words, each lead-in ramp 910 may have a leading edge 914 and a trailing edge 918, with the leading edge 914 axially forward of the trailing edge 918 and sloping radially outward until it meets another portion of the hexagonal feature (e.g., a hexagonal face or point). These ramps 910 may aid in quick engagement of the nut 878 with a mating socket without requiring perfect alignment of the two features.

[0047] 10 , nosepiece 854 is disposed about axis 830. In the example provided, nosepiece 854 includes a front nose member 922 and a rear nose member 926 coupled to one another for common rotation about axis 830 by mating threads 930 (shown in FIG. 10 ), although other configurations may be used. In the example provided, mating threads 930 are left-handed threads. The rear end of front nose member 922 is coupled to the front end of rear nose member 926 by threads 930, and a lip 934 on front nose member 922 may abut rear nose member 926 when fully engaged.

[0048] The front nose member 922 is disposed around the collet 858. The rear nose member 926 is disposed around the collet 858 and the drive shaft 826. The front end of the front nose member 922 defines a second socket 938 (e.g., second socket 318 in FIG. 3) configured to engage with the handling member 218 (FIG. 3) of the nut 18 (FIG. 3). With reference to FIGS. 10 and 11 , the front end of the rear nose member 926 defines an internal socket 942 and a spring seat 946. The internal socket 942 is configured to engage with the nut 878 defined by the exterior of the collet 858. The first spring 838 is coaxial with the axis 830 and is radially disposed between the drive shaft 826 and the rear end of the rear nose member 926. One end of first spring 838 seats in spring seat 946 to bias nosepiece 854 toward an extended position in which socket 942 engages nut 878 of collet 858 .

[0049] 12 , clutch 834 includes a plurality of stationary lugs 1010 and a plurality of rotating lugs 1014. The stationary lugs 1010 are fixed relative to gearbox 822, and the rotating lugs 1014 extend from the aft end of aft nose member 926 of nosepiece 854. In the example provided, clutch 834 includes an annular body 1018 fixedly attached to gearbox 822, with each stationary lug 1010 extending radially inward into a central bore 1022 in annular body 1018. In the example provided, each stationary lug 1010 is defined by a corresponding lug block 1026 attached to annular body 1018, although other configurations may be used.

[0050] In the example provided, each stationary lug 1010 has a flat surface 1030 and an angled surface 1034, and each rotating lug 1014 has a corresponding flat surface 1038 and a corresponding angled surface 1042. The aft end of the aft member of nosepiece 854 extends into central bore 1022 of annular body 1018. Nosepiece 854 is axially movable relative to stationary lugs 1010 between an extended position and a retracted position. In the extended position, rotating lugs 1014 disengage from stationary lugs 1010, and nosepiece 854 is free to rotate relative to annular body 1018. As described above, socket 942 may be engaged with nut 878 of collet 858 in this extended position. In the retracted position, clockwise rotation of nosepiece 854 (as viewed in FIG. 12 ) causes flat surface 1038 of rotatable lug 1014 to engage flat surface 1030 of stationary lug 1010, preventing rotation of nosepiece 854, while counterclockwise rotation (as viewed in FIG. 12 ) causes angled surface 1042 of rotatable lug 1014 to engage angled surface 1034 of stationary lug 1010, thereby allowing the nosepiece to move axially toward the extended position until rotatable lug 1014 and stationary lug 1010 disengage. When in the retracted position, socket 942 disengages from nut 878 of collet 858.

[0051] 10 and 13-16, a retaining sleeve 850 is disposed about a nosepiece 854, with the forward end of the retaining sleeve 850 defining a socket 1046. The aft end of the retaining sleeve 850 is received within a central bore 1022 of the annular body 1018. In the example provided, an O-ring 1050 is disposed within the central bore 1022 to provide friction resisting rotation of the retaining sleeve 850 relative to the annular body 1018. In the example provided, the retaining sleeve 850 is prevented from axially rearward movement by a retaining ring 1054 received within a groove 1058 of the retaining sleeve 850, although other configurations may be used. A plurality of balls 1062 are disposed within the sockets 1046 of the retaining sleeve 850. Each ball 1062 is positioned within a corresponding recess 1066 defined in the outer surface of the nosepiece 854. Each recess 1066 opens through a corner of the second socket 938 so that a corner (e.g., a corner of a hexagon) of the handling member 218 of the nut 18 can extend into the recess 1066. Referring to FIG. 13 , when the nosepiece 854 is not rotating about the axis 830, the ball 1062 fits within the corner of the socket 1046 with clearance for the corner of the handling member 218 of the nut 18. Referring to FIG. 14 , when the nosepiece 854 is rotating, rotation of the retaining sleeve 850 is resisted by the O-ring 1050 ( FIGS. 9 and 10 ), the nosepiece 854 rotates the ball 1062, and the socket 1046 acts as a cam, urging the ball 1062, acting as a follower, radially inward into contact with the handling member 218 of the nut 18. In alternatives not shown, one ball 1062 may be used, or more than two balls 1062 may be used. In other alternatives not shown, shapes other than spherical balls may be used as followers (e.g., cylindrical rollers).

[0052] 15 and 16 , the radially inward pressure of the ball 1062 against the handling member 218 of the nut 18 resists axial movement of the handling member 218 relative to the nosepiece 854 and is sufficient to overcome the biasing force of the second spring 842 which biases the ejector pin 846 forward. The retaining lip 158 overlaps the handling member 218 of the nut 18, thereby retaining both the lug 118 and the handling member 218 of the nut 18 while the nosepiece 854 rotates. When the nosepiece 854 stops rotating, the ball 1062 releases the handling member 218 of the nut 18 and the second spring 842 pushes the ejector pin 846 forward, which pushes the lug 118 and handling member 218 of the nut 18 forward and out of the tool 810.

[0053] It should be noted that the present disclosure is not limited to the forms described and illustrated by way of example. Numerous modifications have been described and are more than part of the knowledge of those skilled in the art. These modifications and additional modifications, as well as any replacement by technical equivalents, can be added to the present description and drawings without departing from the scope of protection of the present disclosure and this patent.

[0054] As used herein, the phrase at least one of A, B, and C should be construed to mean a non-exclusive logical OR (A or B or C), and not to mean "at least one of A, at least one of B, and at least one of C."

[0055] Unless otherwise expressly indicated, all numerical values ​​expressing mechanical / thermal properties, compositional percentages, dimensions and / or tolerances, or other characteristics should be understood to be modified by the word "about" or "approximately" when describing the scope of this disclosure. This modification is desirable for a variety of reasons, including industry practices, manufacturing techniques, and testing performance.

[0056] The terms used herein are intended to describe particular exemplary embodiments and are not limiting. The singular forms "a," "an," and "the" may be intended to include the plural unless the context clearly dictates otherwise. The terms "comprise" and "have" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring performance in the particular order described or illustrated, unless expressly identified as such. It should also be understood that additional or alternative steps may be employed.

[0057] The description of the present disclosure is merely exemplary in nature, and thus, examples that do not depart from the essence of the disclosure are intended to be within the scope of the present disclosure. Such examples should not be considered a departure from the spirit and scope of the present disclosure. The broad teachings of the present disclosure can be embodied in various forms. Thus, while the present disclosure includes specific examples, the true scope of the disclosure should not be so limited, as other modifications will become apparent from a consideration of the drawings, the specification, and the following claims. The inventions described in the original claims of this application are set forth below. [1] 1. A blind fastener for connecting a plurality of workpieces, comprising: a bolt including a shaft, a bolt head, and a lug, the bolt head being disposed between the shaft and the lug and extending radially outward from the shaft, an end of the shaft opposite the bolt head defining external threads, the lug including a first tool engaging portion and a first weakened portion frangibly coupling the lug to the bolt head; a nut including a sleeve, a nut head, and a handling member, the sleeve including a central bore configured to receive the shaft and defining internal threads configured to mate with the external threads, the nut head being disposed between the handling member and the sleeve, the nut head extending radially outward from the sleeve and defining a recess configured to receive the bolt head, the handling member being configured to surround at least a portion of the lug, the handling member including a second frangible portion and a second tool engaging portion, the second frangible portion frangibly coupling the second tool engaging portion to the nut head; A blind fastener comprising: [2] A blind fastener as described in [1], wherein the end face of the bolt head is flush with the end face of the nut head or is recessed from the end face of the nut head when the bolt is fully threaded onto the nut. [3] [1] A blind fastener as described in [1], wherein the first weakened portion is configured to break from the bolt head so that an end face of the bolt head is flush with or recessed from the front faces of the plurality of workpieces, and the second weakened portion is configured to break from the nut head so that an end face of the nut head is flush with or recessed from the front faces of the plurality of workpieces. [4] The blind fastener according to [1], wherein the first tool engagement portion includes a lead-in ramp. [5] The blind fastener according to [1], wherein the second tool engagement portion includes a lead-in ramp. [6] The blind fastener according to [1], wherein the second weak portion is entirely located radially inside the outermost periphery of the nut head. [7] [1] The blind fastener according to [1], wherein the handling member defines a bore having a diameter equal to the outermost diameter of the recess. [8] [1] The blind fastener according to [1], wherein the lug includes a retaining lip, and the handling member defines a bore having a diameter smaller than the diameter of the retaining lip. [9] [8] A blind fastener as described in [8], wherein the retaining lip extends radially outward of the first tool engagement portion.

[10] [9] A blind fastener as described in [9], wherein the handling member is entirely located radially outside the first tool engagement portion.

[11] The blind fastener according to [1], wherein the blind fastener is composed of two pieces when in a pre-installed state, the bolt being the first piece of the two pieces and the nut being the second piece of the two pieces.

[12] [1] The blind fastener according to [1], wherein the second weakened portion defines a break neck extending around the entire circumference of the nut.

[13] [1] The blind fastener according to [1], wherein the first weakened portion defines a break neck extending around the entire circumference of the bolt.

[14] [1] A blind fastener as described in [1], wherein when the blind fastener is in a pre-installed state, the sleeve includes a ductile region having a hardness lower than that of the nut head, a portion of the sleeve between the ductile region and the nut head, and a portion of the sleeve at the female thread.

[15] [1] A blind fastener as described in [1], wherein when the blind fastener is in a pre-installed state, the sleeve includes a variable annealed region having a hardness lower than that of the nut head and lower than that of the portion including the female thread.

[16] 1. A tool for installing blind fasteners including bolts and nuts, comprising: A drive member; a collet driven by the drive member to engage the bolt; a nosepiece for retaining the nut and preventing it from rotating during installation of the blind fastener, the nosepiece being movable between a first position in which the nosepiece is driven by the collet and rotates with the collet, and a second position in which the nosepiece is rotationally stationary despite rotational movement of the collet; A tool that includes:

[17] a retaining sleeve disposed about the nosepiece and defining a cam; a follower disposed between the retaining sleeve and the nosepiece;

[16] The tool of

[16] , comprising: a retaining sleeve having a retaining sleeve configured to retain a nut and a cam configured to move the cam follower radially inward relative to a tool engagement portion of the nut.

[18]

[17] The tool according to

[17] , further comprising an ejector pin and a spring biasing the ejector pin toward an extended position relative to the collet.

[19] further comprising a plurality of stationary lugs;

[16] The tool of

[16] , wherein the nosepiece includes a plurality of rotating lugs configured to engage the stationary lugs when the collet is in the second position.

[20]

[19] The tool of

[19] , wherein each of the stationary lugs includes an inclined surface and each of the rotating lugs includes an inclined surface.

Claims

1. 1. A tool for installing blind fasteners including bolts and nuts, comprising: A drive member; a collet driven by the drive member to engage the bolt; a nosepiece for retaining the nut and preventing it from rotating during installation of the blind fastener, the nosepiece being movable between a first position in which the nosepiece is driven by the collet and rotates with the collet, and a second position in which the nosepiece remains rotationally stationary despite rotational movement of the collet; a plurality of stationary lugs, the nosepiece including a plurality of rotating lugs configured to engage the plurality of stationary lugs when the collet is in the second position; Equipped with each of the plurality of stationary lugs includes an inclined surface; and each of the plurality of rotating lugs includes an inclined surface; the inclined surface of each of the plurality of stationary lugs slopes from a proximal end of each of the plurality of stationary lugs to a distal end of each of the plurality of stationary lugs; the inclined surface of each of the plurality of rotation lugs is inclined from the proximal end of each of the plurality of rotation lugs to the distal end of each of the plurality of rotation lugs; tool.

2. a retaining sleeve disposed about the nosepiece and defining a cam; a follower disposed between the retaining sleeve and the nosepiece; 2. The tool of claim 1, wherein rotation of the nosepiece relative to the retaining sleeve causes the cam to move the follower radially inward relative to a tool engaging portion of the nut.

3. The tool of claim 2 further comprising an ejector pin and a spring biasing the ejector pin toward an extended position relative to the collet.

4. 1. A blind fastener for connecting a plurality of workpieces, comprising: a bolt including a shaft, a bolt head, and a lug, the bolt head being disposed between the shaft and the lug and extending radially outward from the shaft, an end of the shaft opposite the bolt head defining external threads, the lug including a first tool engaging portion and a first weakened portion frangibly coupling the lug to the bolt head; a nut including a sleeve, a nut head, and a handling member, the sleeve including a central bore configured to receive the shaft and defining internal threads configured to mate with the external threads, the nut head being disposed between the handling member and the sleeve, the nut head extending radially outward from the sleeve and defining a recess configured to receive the bolt head, the handling member being configured to surround at least a portion of the lug, the handling member including a second frangible portion and a second tool engaging portion, the second frangible portion frangibly coupling the second tool engaging portion to the nut head; Equipped with the lug includes a retaining lip, and the handling member defines a bore having a diameter smaller than a diameter of the retaining lip; the first tool engaging portion includes a lead-in ramp; Blind fastener.

5. 5. A blind fastener according to claim 4, wherein the end face of the bolt head is flush with the end face of the nut head or is recessed from the end face of the nut head when the bolt is fully threaded onto the nut.

6. 5. The blind fastener of claim 4, wherein the first weakened portion is configured to break from the bolt head so that an end face of the bolt head is flush with or recessed from the front faces of the plurality of workpieces, and the second weakened portion is configured to break from the nut head so that an end face of the nut head is flush with or recessed from the front faces of the plurality of workpieces.

7. The blind fastener of claim 4 , wherein the second tool engaging portion includes a lead-in ramp.

8. 5. The blind fastener according to claim 4, wherein the second weakened portion is entirely located radially inward of the outermost periphery of the nut head.

9. The blind fastener according to claim 4 , wherein the diameter of the bore is equal to the outermost diameter of the recess.

10. The blind fastener according to claim 4 , wherein the retaining lip extends radially outwardly of the first tool engaging portion.

11. 11. The blind fastener of claim 10, wherein the handling member is entirely radially outward of the first tool engaging portion.

12. 5. The blind fastener of claim 4, wherein the blind fastener is comprised of two pieces when pre-installed, the bolt being the first piece of the two pieces and the nut being the second piece of the two pieces.

13. 5. The blind fastener of claim 4, wherein the second weakened portion defines a breakneck extending around the entire circumference of the nut.

14. 5. The blind fastener of claim 4, wherein the first weakened portion defines a breakneck extending around the entire circumference of the bolt.

15. 5. The blind fastener according to claim 4, wherein when the blind fastener is in a pre-installed state, the sleeve includes a ductile region having a hardness lower than that of the nut head, a portion of the sleeve between the ductile region and the nut head, and a portion of the sleeve at the female threads.

16. 5. The blind fastener according to claim 4, wherein when the blind fastener is in a pre-installed state, the sleeve includes a variable annealed region having a hardness lower than that of the nut head and lower than that of the portion including the internal threads.

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