D ESCRI PTI O N BACKGROUND OF THE INVENTION

[Para 1 ] The present invention generally relates to wrenching tools. More specifically, the present invention is directed to a fastener tool assembly for installing and ejecting breakaway torque nuts.

[Para 2] The aerospace industry has made use of "broached-pin" fastening systems for over fifty years. There are many variations, all having in common a method of keeping the bolt or pin from rotating while a nut element is threaded onto it and tightened. Many of the fastening systems used in the aerospace industry are of the frangible fastener type. One such example is the Hi-Lok ^® fastening system. Such frangible fasteners are used extensively in the aerospace industry due to their simplicity, consistently controlled preload torque and minimum size and weight.

[Para 3] FIGURES 1 -4 illustrate a typical frangible fastening system. A bolt 1 0 is extended through the objects 1 2 and 1 4 to be fastened to one another, as illustrated in FIGS. 1 and 2. A threaded portion 1 6 of the bolt extends beyond the aligned objects 1 2 and 1 4. Access to the head 32 of the bolt 1 0 is usually not possible, and for reasons of weight saving and aerodynamics, the heads 32 of the fasteners are flat so as to be flush with the skin of the aircraft structure, or only protrude slightly. Moreover, these heads 32 do not have any external "hex" or other shape to grip with a wrench to keep the bolt 1 0 from rotating and turning. Instead, the threaded end 1 6 of the bolt 1 0 is provided with an internal hex recess 1 8 into which a hex-Allen key wrench 20 may be inserted to hold the bolt 1 0 stationary while an internally threaded nut 22 is fastened thereto.

[Para 4] As illustrated in FIGS. 2 and 3 , the operator holds the hex key Allen wrench 20 with one hand, while operating a wrench, typically having a socket 24 at an end thereof, to hold the bolt 1 0 in place while the nut 22 is fastened onto the threaded portion 1 6 thereof. Power tools have been developed which incorporate the hex key 20 into the tool. In the same manner, the power tool holds the hex key 20 stationary while the socket 24 is used to thread the nut element 22 onto the threaded end 1 6 of the bolt 1 0.

[Para 5] The nut 22 includes a wrenching ring 26 which is configured to engage the socket 24 and an internally threaded collar portion 28. An

intermediate neck portion 30 shears the frangible wrenching ring portion 26 from the collar 28 when the applied torque exceeds a predetermined torsional loading, as illustrated in FIG. 4.

[Para 6] The fasteners are applied with one of a variety of wrenching tools which engage the wrenching ring 26 to apply rotational force to the threaded collar 28 and twist the wrenching ring from the threaded collar when the predetermined torsional loading is exceeded. The break-off torque depends on the depth of the groove 30 in the neck which can be selected to meet different torque requirements. [Para 7] There are typically very strict quality control requirements and measu res taken with respect to the installation of breakaway torque nut airframe fasteners. For every breakaway torque nut 22 and bolt 1 0 used in constructing or repairing the aircraft or other device, a strict accounting of each detached wrenching ring of the breakaway torque nut is required. In some cases, the detached wrenching ring becomes lodged within the open end of the socket used to install the breakaway torque nut 22 to the bolt 1 0. In this case, the installer must tap the end of the socket 24 containing the wrenching ring 26 to dislodge it from the socket 24. This must be done carefully so that the detached wrenching ring 26 does not become lost. In other instances, the detached wrenching ring 26 easily slips out of and falls away from the socket 24. Of course, this increases the chances that the detached wrenching ring 26 will fall or roll, etc. into an undesirable place or even become lost. In such cases, the installer must cease his or her work and find the lost wrenching ring 26. In some cases, this requires the halting of the manufacturing line until the lost wrenching ring 26 is located and retrieved.

[Para 8] Accordingly, there is a continuing need for a fastener tool assembly for installing and ejecting wrenching rings of breakaway torque nuts. Such an assembly should controllably contain the detached wrenching ring until it is intentionally removed from the assembly. Such an assembly shou ld also permit the installation of several breakaway torque nuts to bolts of the fastener system before requiring that the wrenching rings be removed and collected so as to increase the productivity of the worker. The present invention fulfills these needs, and provides other related advantages.

SUMMARY OF THE INVENTION

[Para 9] The present invention resides in a fastener tool assembly for installing and ejecting breakaway torque nuts. The assembly generally comprises a socket having a first end configured to attach to a driver of a fastener tool. A second end of the socket, generally opposite the first end, is configured to operably engage a detachable wrenching ring of a breakaway torque nut. A generally cylindrical sidewall extends between the first end and the second end, the sidewall having a window formed transversely therein intermediate the first and second ends. A lower edge of the window is spaced from a lower edge of the socket at least a distance corresponding to a plurality of stacked wrenching rings. The window is sized and configured to permit at least one wrenching ring to pass therethrough.

[Para 1 0] The socket includes a catch configured to permit insertion of the wrenching ring into the second end of the socket, but prevent the detached wrenching ring from freely falling out of the second end of the socket. The catch typically comprises a resilient ring or clip disposed within the socket adjacent to the second end.

[Para 1 1 ] In a particularly preferred embodiment, a gate is associated with the window. The gate is adapted to selectively permit passage of a detached wrenching ring through the window or prevent passage of the detached wrenching ring through the window. The gate typically comprises a sleeve slidably disposed on the sidewall of the socket, which has an aperture selectively alignable with the window. The sleeve is typically comprised of a resilient material, and includes an elongated slit providing a snap-fit connection to the socket. The sleeve may be disposed over a recess portion of the sidewall, intermediate the first and second ends. The sleeve includes a tab extending into the aperture, which is configured to engage an edge of the window.

[Para 1 2] A set screw extends through the sidewall of the socket and into engagement with the driver of the fastening tool. At the lower edge of the socket, a cover comprised of a material having a low coefficient of friction is attached thereto. The cover may comprise a self-lubricating Teflon material. [Para 1 3] The socket may be attached to a wrench, which includes a handle having a ratchet head. The driver is operably coupled to the ratchet head and the socket. The ratchet head and driver have aligned passageways adapted for the pin to pass therethrough, and through the socket to a bolt of the fastener.

[Para 1 4] Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[Para 1 5] The accompanying drawings illustrate the invention. In such drawings: [Para 1 6] FIGURE 1 is a partially cross-sectional and perspective view of a prior art bolt and nut element of a frangible air frame fastening system for attaching two objects;

[Para 1 7] FIGURE 2 is a similar view as FIG. 1 , illustrating the nut element being fastened to the bolt;

[Para 1 8] FIGURE 3 is a view similar to FIG. 2 , illustrating the nut element fastened to the bolt;

[Para 1 9] FIGURE 4 is a perspective and cross-sectional view illustrating the shearing of the wrenching ring from the collar once the collar and bolt have been fully attached to one another;

[Para 20] FIGURE 5 is a perspective view of the fastener tool assembly of the present invention being utilized to install breakaway torque nuts to

corresponding bolts of a fastener system;

[Para 21 ] FIGURE 6 is a partially exploded perspective view of a fastener tool assembly embodying the present invention;

[Para 22] FIGURE 7 is a side perspective view of a socket embodying the present invention;

[Para 23] FIGURE 8 is a front elevational view of the socket of FIG. 7;

[Para 24] FIGURE 9 is a side elevational view of the socket of FIG. 7;

[Para 25] FIGURE 1 0 is an end view taken generally along line 1 0- 1 0 of FIG. 9;

[Para 26] FIGURE 1 1 is an end view taken generally along line 1 1 - 1 1 of FIG. 9;

[Para 27] FIGURE 1 2 is a cross-sectional view taken generally along line 1 2- 1 2 of FIG. 7; [Para 28] FIGURE 1 3 is an enlarged cross-sectional view of area "1 3" of FIG. 1 2 , illustrating a catch of the assembly;

[Para 29] FIGURE 1 4 is a cross-sectional view of another socket embodying the present invention;

[Para 30] FIGURE 1 5 is a perspective view of a socket cover, used in

accordance with the present invention;

[Para 31 ] FIGURE 1 6 is a cross-sectional view taken generally along line 1 6- 1 6 of FIG. 1 5;

[Para 32] FIGURE 1 7 is a perspective view of a sleeve used in accordance with the present invention;

[Para 33] FIGURE 1 8 is a front elevational view of the sleeve of FIG. 1 7; and [Para 34] FIGURE 1 9 is a side elevational view of the sleeve of FIG. 1 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[Para 35] The present invention is directed to a fastener tool assembly for installing breakaway torque nuts to bolts of a fastening system, and retaining and ejecting in a controlled manner wrenching rings which detach from the torque nuts during installation. Such breakaway torque nuts and bolts are typically used as air frame fasteners of aircraft in aerospace industries.

[Para 36] With reference now to FIG. 5, a fastener tool assembly 1 00

embodying the present invention is shown including a socket 1 02 having a sleeve 1 04 operably disposed thereon, and actuated by means of a wrench 1 06. In this case, the wrench 1 06 is of the manual type operated by a user's hand 34. However, it will be appreciated that the present invention is not limited to such, and instead the fastening tool could comprise a powered wrench device, such as a pneumatic or electric motor-driven wrench device.

[Para 37] It will be seen from FIG. 5 that two objects 1 2 and 1 4 are in the process of becoming connected by means of a series of fasteners, including the aforementioned bolt 1 0 and threaded nut 22 fasteners. As described above, and illustrated in FIG. 5 , as the fastener tool assembly 1 00 of the present invention is used to install the breakaway torque nut 22, the collar portion 28 is left threaded onto the threaded end of the bolt 1 0. However, the wrenching ring portion 26 is captured within the socket 1 02. As will be more fully described herein, the socket 1 02 is designed and configured to retain multiple detached wrenching rings 26 therein, until the wrenching rings 26 are selectively removed from the socket 1 02 , such as by aligning a window of the sleeve 1 04 with the window of the socket 1 02.

[Para 38] With reference now to FIG. 6, a fastener tool assembly embodying the present invention is shown including the manual wrench 1 06 having a handle 1 08 extending from a ratchet head 1 1 0, with a driver 1 1 2 operably connected to the ratchet mechanism (not shown) within the ratchet head 1 1 0, as is known in the art. The ratchet head 1 1 0 includes a passageway 1 1 4 aligned with a passageway 1 1 6 of the driver for insertion of a multi-faceted key or pin 1 1 8 therethrough. The pin 1 1 8 has a number of facets typically corresponding with the number of facets in the recess 1 8 of the bolt 1 0, so as to hold the bolt 1 0 and prevent it from rotating during installation of the breakaway torque nut 22, as illustrated and described above. Typically, the pin 1 1 8 comprises a hex Allen wrench or key.

[Para 39] With reference now to FIGS. 6- 1 2, the socket 1 02 has a first end 1 20 which is configured to attach to the driver 1 1 2 of the fastener tool. FIG. 1 1 illustrates a top view of the socket 1 02, illustrating the first end 1 20 of the socket, and a faceted aperture 1 22 formed in the first end 1 20 for removably receiving the driver 1 1 2 therein. In the embodiment illustrated in FIG. 1 1 , the faceted opening 1 22 is square, so as to be received upon a square-driver type 1 1 2. A threaded aperture 1 24 may extend through an upper portion of the socket for receipt of a set screw 1 26 therethrough and into engagement with the driver 1 1 2, so as to more securely hold the socket 1 02 to the driver 1 1 2.

[Para 40] The second end 1 28 of the socket 1 02 is generally opposite the first end 1 20 and is configured to operably engage the breakaway torque nut 22, and particularly the wrenching ring 26 portion thereof. For example, as illustrated in FIG. 1 0, the second end 28 of the socket 1 02 includes a multi-faceted opening 1 30 which is slightly larger than the multi-faceted wrenching ring 26 of the breakaway torque nut 22. Typically, the wrenching ring 26 and the opening 1 30 are hex-shaped, so as to include six facets, although the invention is not limited to such.

[Para 41 ] It will be understood that the first end 1 20 and the generally opposite second end 1 28 of the socket 1 02 are aligned generally axially with one another. The socket 1 02 is generally hollow, and includes a passageway extending therethrough such that the pin 1 1 8 of the fastener tool 1 06 can extend therethrough and into engagement with the recess 1 8 of the bolt 1 0, as described above.

[Para 42] A sidewall 1 32 extends between the first end 1 20 and the second end 1 28. The sidewall is typically generally cylindrical in configuration. The sidewall 1 32 may be a wall having a smooth outer surface, as illustrated, or be multi-faceted, but in any event it is generally considered cylindrical in nature.

[Para 43] A window 1 34 is formed transversely within the sidewall 1 32 , intermediate the first and second ends 1 20 and 1 28. The window 1 34 is sized and configured to permit at least one wrenching ring 26 to pass therethrough, as illustrated in FIG. 5. A lower edge 1 36 defining the window 1 34 is spaced a predetermined distance from the lower edge 1 38 of the socket, which

corresponds to a plurality of stacked wrenching rings. That is, the lower edge 1 36 of the window 1 34 is preferably spaced a distance from the lower edge 1 38 of the socket 1 02 such that two or more detached wrenching rings 26 can temporarily reside within the lower portion of the socket therebetween. An upper edge 1 40 of the window is spaced a sufficient distance from the lower edge 1 36 so as to allow passage of at least one wrenching ring 26 therethrough. Sidewalls 1 42 and 1 44 of the window 1 34 are spaced sufficiently apart so as to permit at least one wrenching ring 26 to pass through the window 1 34.

[Para 44] In a particularly preferred embodiment, the window 1 34 is formed by the lower edge 1 36 being cut, or otherwise formed, generally directly into the wall 1 32 in a transverse manner with respect to the longitudinal axis of the socket 1 02 a predetermined minimum distance. From the upper edge 1 40, side edges 1 42 and 1 44 are formed as sloping, curved cuts or lines so as to meet, or even extend beyond, the lower edge 1 36, as illustrated in FIGS. 7-9 and 1 2. This configuration has been found to be particularly helpful in removing detached wrenching rings 26, although other cut-out window configurations are

contemplated by the invention.

[Para 45] The following are examples of the dimensions of a socket 1 02 and window 1 34 embodying the present invention. For a socket 1 02 having a length of 2" (approximately 50 mm) and having a 5 / 1 6" (approximately 8 mm) faceted opening for engagement with the torque nut 22 , the approximate width of the socket will be approximately .446" (approximately 1 1 mm). If the driver is 1 /4" (approximately 6 mm), a faceted opening of 1 1 /32" (approximately 8 mm) will be formed in the first end of the socket 1 02. A distance from the lower edge 1 38 of the socket 1 02 to the lower edge 1 36 of the window 1 34 will be approximately 1 12" (approximately 1 2 mm). The detached wrenching rings have a height of approximately 1 /8" (approximately 3 mm), enabling at least three or four wrenching rings to be disposed within the socket 1 02 before they are exposed to the window 1 34. The depth of the window 1 34 is approximately 1 /4"

(approximately 6 mm), and the distance between the lower edge 1 36 and the upper edge 1 40 of the window 1 34 is approximately 1 /2" (approximately 1 2 mm) to enable the easy removal of one or more wrenching rings 26 from the socket 1 02. Of course, it will be appreciated that these dimensions may be adjusted depending upon the size of the socket 1 02 , the size of the detachable wrenching ring 26, etc. [Para 46] With reference now to FIGS. 1 3 and 1 4, the socket 1 02 preferably includes a catch 1 46, configured to permit insertion of the wrenching ring 26 into the second end 1 30 of the socket 1 02, but prevent the detached wrenching ring 26 from freely falling out of the second end 1 30 of the socket 1 02. In one embodiment, the catch 1 46 comprises a resilient ring disposed within an annular groove formed on the interior surface of the sidewall 1 32 of the socket 1 02 adjacent to the second end 1 28 thereof. The resilient ring 1 46, for example, can be comprised of a metallic ring having spring characteristics and a notch formed therein so as to enable insertion of the ring within the annular groove 1 48. The ring 1 46 is biased slightly so as to present a reduced diameter in the opening 1 30 of the socket 1 02 , but be pressed inwardly into the groove 1 48 so as to enable passage of the wrenching ring 26 thereby.

[Para 47] When the first wrenching ring 26 is initially detached, the resilient ring or catch 1 46 holds the detached wrenching ring in place within the socket 1 02 so that it does not fall from the open end 1 30 of the socket 1 02. When a su bsequent breakaway torque nut 22, and particularly the wrenching ring portion 26 thereof, is engaged by the open end 1 30 of the socket 1 02 , the first detached wrenching ring 26 is pushed upwardly into the internal chamber and body of the socket 1 02 , as illustrated in FIG. 5. The second wrenching ring 26, once detached, is held in place by the catch resilient ring 1 46. This occurs until a desired number of wrenching rings have been removed, or no additional detached wrenching rings can be fit within the inner chamber 1 50 of the socket 1 02. [Para 48] With reference now to FIGS. 1 5 and 1 6, the socket 1 02 is typically comprised of a hard and durable material, such as metal, carbon fiber, or the like so as to apply the needed force to the breakaway torque nut 22 and fasten it to the bolt 1 0. This can present problems, however, in that the lower edge 1 38 of the socket 1 02 can scratch or otherwise mar the surface of the objects to be joined to one another. This is particularly the case when the outer surface of the object facing the socket 1 02 has been painted or finished. To reduce or even eliminate the possibility of such scratching or marring, a cover 1 52 comprised of a material having a low coefficient of friction is attached to the lower edge 1 38 and lower end 1 28 of the socket 1 02. This can be seen, for example, in FIGS. 6 and 1 4. The material having a low coefficient of friction may comprise a self- lu bricating Teflon material. The cover 1 52 may be formed as a separate piece, as illustrated in FIGS. 1 5 and 1 6, and friction-fitted or adhered onto the end 1 28 of the socket 1 02 , or the end 1 28 of the socket 1 02 may be dipped into a melted material having a low coefficient of friction, which later hardens and forms a scratch resistant surface which might come into contact with the object being fastened.

[Para 49] In the embodiment illustrated in FIGS. 1 4- 1 6, the cover 1 52 includes a first opening 1 54 which has a diameter which is approximately equal or slightly greater than the outer diameter of the end 1 28 of the socket 1 02, so as to fit thereover. A second, somewhat smaller, opening 1 56 is formed at generally the opposite end of the cover 1 52 which corresponds with the opening 1 30 of the socket 1 02 so as to permit passage of the necessary portions of the breakaway torque nut 22 therethrough.

[Para 50] With reference now to FIGS. 6 and 1 7- 1 9, the assembly of the present invention includes a gate associated with the window 1 34 of the socket, which is adapted to selectively allow the user to permit passage of one or more detached wrenching rings 26 through the window 1 34, as illustrated in FIG. 5, or prevent passage of a detached wrenching ring 26 through the window 1 34. In the illustrated embodiment, the gate comprises a sleeve 1 04 slidably disposed on a sidewall 1 32 of the socket 1 02. The sleeve 1 04 is typically generally cylindrical in shape and has generally opposite openings 1 58 and 1 60. Within the body 1 62 of the sleeve 1 04 an aperture 1 64 is formed. The aperture 1 64 is selectively alignable with the window 1 34 of the socket 1 02 , as illustrated in FIG. 5, to permit passage of detached wrenching rings 26 therethrough and from the interior of the socket 1 02 to the exterior thereof. The aperture 1 64 may be approximately the size of the socket window 1 34, or may be larger or smaller, but in any case is sufficiently sized so as to permit a detached wrenching ring 26 to pass therethrough.

[Para 51 ] The body 1 62 of the sleeve 1 04 has an internal diameter which is slightly greater than the exterior diameter of the sidewall 1 32 of the socket 1 02 over which it is disposed. However, the sleeve 1 04 is configured so as not to easily slip off of the socket 1 02. This can be done in a different number of ways. For example, the sleeve 1 04 may be comprised of resilient material and include one or more slits 1 66 which allow the sleeve 1 04 to be slightly enlarged in diameter so as to be snap-fit over the socket 1 02. In such case, slits 1 66 may extend from the open ends 1 58 and 1 60 generally along the length of the body 1 62, or to the aperture 1 64, as illustrated. Although a snap-fit connection will be made between the sleeve 1 04 and the socket 1 02 , the sleeve 1 04 can still be manually slid and rotated about the exterior surface of the socket 1 02.

[Para 52] With reference again to FIG. 1 4, the sidewall 1 32' of the socket 1 02' may have a section of reduced diameter, forming a recessed area, corresponding to the length and size of the sleeve 1 04 such that the sleeve 1 04 can be fit over that portion of the socket 1 02 and be freely rotated in order to selectively align and misalign the apertu re 1 64 of the sleeve 1 04 and the window 1 34 of the socket 1 02 , to permit selective removal of the wrenching rings 26.

[Para 53] It has been found that as the socket 1 02 is rotated during the installation of the breakaway torque nut 22 onto the bolt 1 0, the sleeve 1 04 can either be rotated or remain stationary, which can cause inadvertent alignment of the aperture 1 64 with the window 1 34, permitting detached wrenching rings 26 within the socket 1 02 to fall out of the socket 1 02 unintentionally. In order to prevent this, a tab 1 68 is formed in the body 1 62 on an edge of the aperture 1 64, as illustrated, the tab 1 68 engaging an edge of the window 1 34 so as to control the alignment of the aperture 1 64 and the window 1 34. That is, when the socket 1 02 is rotated by the driving tool, the tab 1 68 which extends into the aperture 1 64 of the sleeve 1 04 will come into engagement with a side edge 1 42 or 1 44 of the window 1 34 of the socket 1 02, causing the sleeve 1 04 to be rotated with the socket 1 02. [Para 54] When the desired number or maximum number of detached wrenching rings 26 are disposed within the socket 1 02 , the user simply slides or rotates the sleeve 1 04 until the aperture 1 64 is generally aligned with the socket window 1 34, so as to controllably remove the detached wrenching rings 26. This can be done, for example, by aligning the aperture 1 64 of the sleeve 1 04 and the socket window 1 34, and tilting the socket towards its generally horizontal position such that the detached wrenching rings 26 slide out of the aligned aperture 1 64 and window 1 34. In this manner, the installer may controllably move the detached wrenching rings 26 into his or her palm or container such that the detached wrenching rings 26 do not become lost and unaccounted for.

[Para 55] Although several embodiments have been described in detail for pu rposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.