TWO-PIECE BLIND FASTENER AND INSTALLATION TOOL
20220176438 · 2022-06-09
Assignee
Inventors
- Cristinel COBZARU (Murrieta, CA, US)
- Brian HOFFARTH (Santa Ana, CA, US)
- Claude COUILLANDEAU (Condrieu, FR)
Cpc classification
F16B5/045
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B21J15/26
PERFORMING OPERATIONS; TRANSPORTING
F16B19/1054
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
B21J15/04
PERFORMING OPERATIONS; TRANSPORTING
B21J15/26
PERFORMING OPERATIONS; TRANSPORTING
B25B27/00
PERFORMING OPERATIONS; TRANSPORTING
F16B19/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A blind fastener for connecting workpieces includes a bolt and nut. The bolt includes a shaft, bolt head, and lug. The bolt head is between the shaft and lug and extends radially outward from the shaft. The shaft defines external threads opposite the bolt head. The lug includes a first tool engagement portion and a first frangible portion that frangibly couples the lug to the bolt head. The nut includes a sleeve, nut head, and handling member. The shaft is threadably received in the sleeve. The nut head extends radially outward from the sleeve and defines a recess that receives the bolt head. The handling member surrounds at least a portion of the lug. The handling member includes a second frangible portion and a second tool engagement portion. The second frangible portion frangibly couples the second tool engagement portion to the nut head.
Claims
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 engagement portion and a first frangible portion that frangibly couples the lug to the bolt head; and 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 engagement portion, the second frangible portion frangibly coupling the second tool engagement portion to the nut head.
2. The blind fastener of claim 1, wherein an end surface of the bolt head is flush with or recessed from an end surface of the nut head when the bolt is fully threaded into the nut.
3. The blind fastener according to claim 1, wherein the first frangible portion is configured to break off from the bolt head such that an end surface of the bolt head is flush with or recessed from a front surface of the plurality of workpieces, and the second frangible portion is configured to break off from the nut head such that an end surface of the nut head is flush with or recessed from the front surface.
4. The blind fastener according to claim 1, wherein the first tool engagement portion includes lead-in ramps.
5. The blind fastener according to claim 1, wherein the second tool engagement portion includes lead-in ramps.
6. The blind fastener according to claim 1, wherein the second frangible portion is entirely radially inward of an outermost perimeter of the nut head.
7. The blind fastener according to claim 1, wherein the handling member defines a bore having a diameter equal to an outermost diameter of the recess.
8. The blind fastener according to claim 1, wherein the lug includes a retaining lip and the handling member defines a bore having a diameter that is less than a diameter of the retaining lip.
9. The blind fastener according to claim 8, wherein the retaining lip extends radially outward of the first tool engagement portion.
10. The blind fastener according to claim 9, wherein the handling member is entirely radially outward of the first tool engagement portion.
11. The blind fastener according to claim 1, wherein the blind fastener consists of two pieces when in a pre-installed condition, the bolt being a first one of the two pieces and the nut being a second one of the two pieces.
12. The blind fastener of claim 1, wherein the second frangible portion defines a break-neck that extends around a full circumference of the nut.
13. The blind fastener of claim 1, wherein the first frangible portion includes a break-neck that extends around a full circumference of the bolt.
14. The blind fastener of claim 1, wherein when the blind fastener is in a pre-installed condition, the sleeve includes a ductile zone that has a hardness that is less than a hardness of the nut head, a portion of the sleeve between the ductile zone and the nut head, and a portion of the sleeve at the internal threads.
15. The blind fastener of claim 1, wherein when the blind fastener is in a pre-installed condition, the sleeve includes a variable annealed zone that has a hardness that is less than a hardness of the nut head and less than a hardness of the portion including the internal threads.
16. A tool for installing a blind fastener including a bolt and a nut, the tool comprising: a driving member; a collet driven by the driving member for engaging the bolt; and an nosepiece for holding the nut and inhibiting the nut 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 to rotate with the collet and a second position in which the nosepiece is rotationally stationary despite rotating action of the collet.
17. The tool according to claim 16 further comprising: a retaining sleeve disposed about the nosepiece and defining a cam; and a follower disposed between the retaining sleeve and the nosepiece, wherein rotation of the nosepiece relative to the retaining sleeve causes the cam to move the follower radially inward against a tool engagement portion of the nut.
18. The tool according to claim 17 further comprising an ejector pin and a spring biasing the ejector pin toward an extended position relative to the collet.
19. The tool according to claim 16 further comprising: a plurality of stationary lugs, wherein the nosepiece includes a plurality of rotary lugs configured to engage the stationary lugs when the collet is in the second position.
20. The tool according to claim 19, wherein each of the stationary lugs includes a ramped face and each of the rotary lugs includes a ramped face.
Description
DRAWINGS
[0011] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
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[0014]
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[0020]
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[0022]
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[0028] 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
[0029] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
[0030] Fastener Assembly
[0031] Referring to
[0032] With additional reference to
[0033] The first workpiece 26 and the second workpiece 30 each define apertures that cooperate when aligned to form an aperture 50 through the first front surface 34 and through the second back surface 46 that is coaxial with the axis 22. The aperture 50 can be countersunk or counter bored from the first front surface 34. In the example provided, the aperture 50 is counter sunk such that it includes a cylindrical inner bore 54 and a contact surface 58 that extends axially at an angle between the inner bore 54 and the first front surface 34.
[0034] 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 the 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 begin at one terminal end 130 of the bolt 14. The stem 122 is disposed axially between the threads 126 and the bolt head 114.
[0035] In one form, the stem 122 has a generally smooth cylindrical first outer surface 134 with a diameter that is greater than or equal to the major diameter of the external threads 126. The external threads 126 extend axially along the shaft 110 until terminating adjacent to the stem 122, though other configurations can be used. In one alternative example, not shown, a sealant or a seal can be disposed between the termination of the external threads 126 and the stem 122 or can be disposed along the stem 122, to seal with the inner surface of the nut 18. The seal (not shown) is configured to inhibit passage of fluids, such as water, oil, fuel, etc. The seal (not shown) can be an elastomeric body, such as an o-ring for example.
[0036] The bolt head 114 is located at an end of the stem 122 that is opposite the external threads 126. The bolt head 114 extends radially outward of the first outer surface 134 of the stem 122.
[0037] Referring to
[0038] Returning generally to
[0039] With specific reference to
[0040] Returning to
[0041] The retainer lip 158 is axially between the first tool engagement portion 150 to the first frangible portion 154 and extends radially outward of the first tool engagement portion 150. In the example provided, the retainer lip 158 has a generally frustoconical shape that widens with increased distance from the first tool engagement portion 150.
[0042] Referring to
[0043] The first frangible portion 154 frangibly couples the retainer lip 158 to the bolt head 114. In the example provided, the outer surface 166 of the first frangible portion 154 is generally cylindrical in shape and has a diameter that is equal to or less than the outermost diameter of the perimeter 142 of the bolt head 114. The first frangible portion 154 narrows from the outer surface 166 to a break-neck 174 that joins the first end surface 146 of the bolt head 114 with the lug 118. In the example provided, the diameter of the break-neck 174 is also less than the diameter of the first outer surface 134 of the stem 122 and extends around a full circumference of the bolt 14.
[0044] Returning to
[0045] The sleeve 210 defines a central bore 230 coaxial with the axis 22 and includes internal threads 234. Referring to
[0046] Referring to
[0047] Referring to
[0048] The nut head 214 is located at an end of the sleeve 210 that is opposite the internal threads 234 and extends radially outward of the sleeve 210. Referring to
[0049] One end of the recess 242 is open through the second end surface 250 and the other end of the recess 242 is open 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 radially outward from the first bore 230 at an angle 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 that is greater than the diameter of the perimeter 142 of the bolt head 114 so that the bolt head 114 can be rotatably received in the recess 242.
[0050] The contact surface 262 of the nut head 214 is at an angle similar to the angle of the clamp surface 138 of the bolt head 114. The inner wall surface 258 of the nut head 214 meets the contact surface 262 at a depth from the second end surface 250 such that when the bolt head 114 is received in the recess 242 the first end surface 146 of the bolt head 114 is flush with or recessed from the second end surface 250 of the nut head 214.
[0051] The handling member 218 includes a second tool engagement portion 266 and a second frangible portion 270 disposed about the axis 22. The handling member 218 defines a second bore 274 coaxial with the axis 22 and open through the terminal end 278 of the nut 18 and open to the recess 242. The second bore 274 surrounds at least a portion of the first frangible portion 154. In the example provided, the second bore 274 has a diameter less than the diameter of the retainer lip 158 of the lug 118, though other configurations can 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 inner wall surface 258 can be formed as a single bore.
[0052] The second tool engagement portion 266 is configured to be engaged by the tool 310 (
[0053] Returning to
[0054] Returning to
[0055] In an alternative form, the handling member 218 can be a part that is formed separately from the rest of the nut 18 (i.e., the sleeve 210 and the nut head 214). In this alternative form, the handling member 218 can be attached to the nut head 214 such as by glue, adhesive, welding, or brazing for example. In this alternative form, the frangible portion 270 is formed by the glue, adhesive, weld, or braze. This alternative form may still narrow to a neck (similar to break-neck 276) at the frangible portion 270 or may not narrow depending on the strength of the glue, adhesive, weld, or braze.
[0056] Installation
[0057] Returning generally to
[0058] In this position, the first socket 314 of the tool 310 can mate with and engage the first tool engagement portion 150 and the second socket 330 of the tool 310 can mate with and engage the second tool engagement portion 266. The tool 310 is then operated in a first mode such that the first socket 314 transmits torque to the bolt 14 in the tightening direction of the threads 126, 234, while the second socket 330 holds the nut 18 rotationally stationary relative to the work pieces 26, 30. The tool 310 inhibits the bolt 14 and nut 18 from moving axially away from the workpieces 26, 30.
[0059] With continued reference to
[0060] Once the bulb 510 is formed, the bulb 510 and sleeve 210 can resist further deformation. Additional torque applied to the bolt 14 above a predetermined torque threshold value can then cause the first frangible portion 154 to break. More specifically, the lug 118 is rotated in the tightening direction while the nut 18 is held rotationally and axially stationary. The threads 126, 234 impart an axial force on the sleeve 210 until the shear strength of the break-neck 174 is exceeded. The break-neck 174 then shears, separating the lug 118 from the bolt head 114. The shearing of the break-neck 174 leaves the first end surface 146 of the bolt head 114 flush with or slightly recessed from the second end surface 250 of the nut head 214, as shown in
[0061] The clamping force of the bulb 510 and the nut head 214 on the workpieces 26, 30 can resist rotation of the nut 18 relative to the workpieces 26, 30. The second socket 330 then applies torque to the handling member 218 in an amount that exceeds a predetermined torque threshold value to cause the second frangible portion 270 to break. More specifically, the second frangible portion 270 shears at the break-neck 276, separating the handling member 218 from the nut head 214. The shearing of the second frangible portion 270 leaves the second end surface 250 of the nut head 214 flush with or recessed from the first front surface 34 of the first workpiece 26, as shown in
[0062] Thus, as shown in
[0063] Tool
[0064] Referring to
[0065] With additional reference to
[0066] Referring to
[0067] Referring to
[0068] Referring to
[0069] The forward nose member 922 is disposed about the collet 858. The rear nose member 926 is disposed about the collet 858 and the drive shaft 826. The forward end of the forward nose member 922 defines a second socket 938 (e.g., the second socket 318 of
[0070] Referring to
[0071] In the example provided, each stationary lug 1010 has a flat face 1030 and an angled face 1034 and each rotary lug 1014 has a corresponding flat face 1038 and a corresponding angled face 1042. The rear end of the rear member of the nosepiece 854 extends into the central bore 1022 of the annular body 1018. The nosepiece 854 is axially movable relative to the stationary lugs 1010 between the extended position and a retracted position. In the extended position, the rotary lugs 1014 are disengaged from the stationary lugs 1010 and the nosepiece 854 is free to rotate relative to the annular body 1018. As described above, the socket 942 can also be engaged with the nut 878 of the collet 858 in this extended position. In the retracted position, rotation of the nosepiece 854 in the clockwise direction (as viewed in
[0072] Referring to
[0073] Referring to
[0074] It should be noted that the disclosure is not limited to the form described and illustrated as examples. A large variety of modifications have been described and more are part of the knowledge of the person skilled in the art. These and further modifications as well as any replacement by technical equivalents may be added to the description and figures, without leaving the scope of the protection of the disclosure and of the present patent.
[0075] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of” A, at least one of B, and at least one of C.
[0076] Unless otherwise expressly indicated, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, manufacturing technology, and testing capability.
[0077] The terminology used herein is for the purpose of describing particular example forms only and is not intended to be limiting. The singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude 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 are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0078] The description of the disclosure is merely exemplary in nature and, thus, examples that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such examples are not to be regarded as a departure from the spirit and scope of the disclosure. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims.