BACKGROUND INFORMATION
Field
Embodiments of the disclosure relate generally to devices for torqueing fasteners and more particularly to a system employing two sockets commonly supported and releasably spaced on an interconnecting shaft to engage two fasteners whereby torque induced by tightening one fastener is reacted in the second fastener and relief of induced load between the sockets is enabled by releasing one or both sockets on the shaft.
Background
Many fasteners in aircraft structures require very high torque, in excess of 2000 inch pounds. Typically one side (either the nut or bolt side) of the fasteners are in confined spaces. Mechanics can use drivers and torque multipliers on an exposed side, along with torque reaction arms to drive the fasteners. The opposite side must also have a wrench (or similar tool) engaged to prevent rotation so the required torque may be achieved. Mechanics in current applications use a hand held wrench to prevent the nut from rotating, without other mechanical assistance. This approach may be impaired by limited access to the fastener to be restrained. Additionally, if the wrench slips, soft tissue injuries or damage to the aircraft structure may be incurred. Some devices react the torque by joining two sockets together rigidly and use an adjacent fastener to react the torque. These structures are not satisfactory because after the fasteners have been driven to the required torque, the preload induced in the sockets is so high they cannot be removed from the fasteners.
It is therefore desirable to provide a method and tool for operation with limited access to allow reaction of torque applied to fasteners during assembly. It is further desirable that the system be releasable to relieve induced preload and allow removal of the tool.
SUMMARY
Embodiments disclosed herein provide a torque reactor having a first socket with a first drive element engaging the first socket and a second socket with a second drive element engaging the second socket. The first drive element has a first receiving channel and the second drive element has a second receiving channel. A shaft is received in the first receiving channel and the second receiving channel. A first engagement mechanism secures the shaft in the first receiving channel and a second engagement mechanism secures the shaft in the second receiving channel.
The embodiments allow a method for reacting torque during torqueing of a fastener. Restraining elements in at least one of a first drive element and a second drive element are released from a shaft and the drive elements are longitudinally adjusted on the shaft to be equivalent to spacing of fasteners onto which first and second sockets are to be placed. The first and second sockets are placed on a fastener and an adjacent fastener. The restraining elements are secured in the first and second drive elements constraining the shaft in the drive elements. The fastener is then torqued and the torque is transmitted in the first socket through the first drive element and shaft to the second drive element and second socket secured to the adjacent fastener employing the arm length of the shaft between the drive elements for mechanical advantage to react the torque. Upon completion of torqueing the fastener, the restraining elements are released thereby releasing any preload established in the sockets.
The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is an upper pictorial depiction of a first embodiment of a torque reactor;
FIG. 1B is a lower pictorial depiction of the first embodiment;
FIG. 1C is a partially exploded view of the first embodiment;
FIG. 1D is an end view of the first embodiment;
FIG. 1E is a pictorial depiction of the first embodiment attached to fasteners for use;
FIG. 2A is an upper pictorial depiction of a second embodiment;
FIG. 2B is a first end view of the second embodiment;
FIG. 2C is an opposite end view of the second embodiment;
FIG. 3A is an upper pictorial depiction of a third embodiment;
FIG. 3B is a lower pictorial depiction of the third embodiment;
FIG. 3C is an end view of the third embodiment;
FIG. 4A is an upper pictorial depiction of a fourth embodiment;
FIG. 4B is a lower pictorial depiction of the fourth embodiment;
FIG. 4C is partially exploded view of the fourth embodiment;
FIG. 5 is a flow chart showing a method reacting torque during fastener installation employing the embodiments disclosed herein;
FIG. 6 is a flow chart depicting an aircraft manufacturing and service method in which the disclosed embodiments may be employed; and,
FIG. 7 is a flow chart depicting an aircraft with which the disclosed embodiments may be employed.
DETAILED DESCRIPTION
Embodiments disclosed herein provide embodiments employing two sockets receivable on adjacent fasteners to react the torque for tightening at least one of the fasteners. A square drive element having a slot is attached to each socket. A shaft is fitted into the slot of each drive element. There is clearance between the shaft and the slot to allow the square drive elements to be adjusted along the length of the shaft. An engagement mechanism is tightened against the shaft to achieve a rigid connection between the sockets. By releasing the engagement mechanism, the drive elements may slide along the shaft (telescope) to accommodate any spacing between fasteners and, after torqueing of the fastener, any preload imposed, which might create binding of the socket on the fastener, may be released. Each drive element also has a cap over the slot to restrain the shaft in the drive elements.
Referring to the drawings, FIGS. 1A and 1B show pictorial depictions and FIG. 1C an exploded view of a first embodiment of the torque reactor. First and second sockets 10a and 10b are configured to engage a first fastener element and an adjacent fastener element. First and second drive elements 12a and 12b are provided to engage the sockets 10a, 10b. For the embodiment shown the engagement is a square drive 14 received in a square relief 16 in each socket 10a, 10b as seen in FIG. 1C. Those skilled in the art will recognize alternative drive configurations for the drive elements and sockets. Each drive element 12a, 12b has a channel 18 which is sized to receive a shaft 20. For the exemplary embodiment, the shaft 20 has a square or rectangular cross section and the channels 18 are quadrilateral in shape to receive the shaft. For the assembled torque reactor as shown in FIG. 1D, the shaft 20 has a first face 22 against which a restraining element of an engagement mechanism may exert force as will be described in greater detail subsequently. A second face 24 on the shaft 20 is urged against a reacting face 26 in the channel 18 as seen in FIG. 1D to frictionally secure the drive element on the shaft. The shaft 20 is retained in the channel 18 of the drive elements 12a, 12b with a cap plate 25 engaged to the drive elements. For the embodiment shown, bolts 27 secure the cap plates 25 to the drive elements 12a, 12b. While shown in the embodiment with two movable drive elements for maximum flexibility in adjustment, one drive element could be fixed to the shaft in alternative embodiments. Additionally, while a cap plate is shown alternative methods for capturing the shaft in the drive elements may be employed which would eliminate the need for a cap.
For the first embodiment, the restraining element employs set screws 28 received through threaded bores 30 in the drive elements 10a, 10b. The shaft 20 is received in channel 18 with sufficient play (as represented by vertical gap 32 and lateral gap 34 for the first embodiment) to allow relaxation of the shaft within the channel for translation of the drive elements 12a, 12b longitudinally along the shaft 20 for repositioning and for relief of any preload induced by torque of fastener elements in the sockets 10a, 10b. In use, the sockets 10a, 10b are engaged on the fastener elements, shown in the exemplary embodiment as fastener nuts 11a, 11b which engage fastener bolts 11c, 11d inserted through bores 8a and 8b in structure 9, shown in phantom, in FIG. 1E, and set screws 28 are tightened and urged against first face 22 of the shaft 20, in turn urging the shaft 20 laterally to frictionally engage second face 24 against the reacting face 26 in the channel 18 to prevent motion of the drive elements 12a, 12b and attached sockets 10a, 10b along the shaft 20. After completion of tightening of the fasteners, for example with wrench 29, any preload induced in the sockets 10a, 10b is released by withdrawing the set screws 28 allowing the drive elements 12a, 12b play on the shaft 20. The torque reactor may then be removed from the fasteners. While two set screws are shown in each drive element for the embodiment in the drawings, a single set screw in each drive element may be employed. Dimensions of the elements of the embodiment in the drawings have been selected for clarity. The overall height of the torque reactor is limited only by sufficient depth in the sockets 10a, 10b to receive the fastener element and cross section of the shaft 20 and resulting depth of drive elements 12a, 12b to structurally react resulting torques. Consequently the overall torque reactor may employ a very low profile enabling use in very compact working spaces.
An alternative restraining element is disclosed in a second embodiment shown in FIGS. 2A-2C. An overcenter cam 36 having a securing face 38 and a releasing face 40 may be rotatably mounted in a slot 42 in each of the drive elements 12a, 12b. A lever arm 44 extending from each cam 36 is employed to rotate the cam from an engaged position urging the securing face 38 against the shaft 20 to a released position allowing free play of the shaft within channel 18. The cams 36 are shown in drive element 12a in the released position and drive element 12b in the engaged position in FIG. 2A. As seen in FIG. 2B for the engaged position, cam 36 has securing face 38 urged against first face 22 of the shaft 20, in turn urging the shaft 20 laterally to frictionally engage second face 24 against the reacting face 26 in the channel 18 to prevent motion of the drive elements 12a, 12b. As in the first embodiment, after completion of tightening of the fasteners, any preload induced in the sockets 10a, 10b is released by rotating the cams 36 with the releasing face 40 adjacent the shaft 20 thereby allowing the drive elements 12a, 12b play on the shaft 20 with gap 34 as seen FIG. 2C. The torque reactor may then be removed from the fasteners.
A third embodiment for lower torque applications is shown in FIGS. 3A-3C. As a simplification, cap plate 25 may be employed as the restraining element. The shaft 20 is received in channel 18 with sufficient play (as represented by vertical gaps 44 and 46) to allow relaxation of the shaft within the channel for translation of the drive elements 12a, 12b longitudinally along the shaft 20 for repositioning and for relief of any preload induced by torque of fastener elements in the sockets 10a, 10b. Each cap plate 25 incorporates a key 49 extending from a bottom surface 48 to be received in a groove 50 in the shaft 20. In use, the sockets 10a, 10b are positioned on the fastener elements and bolts 27 are tightened and urging key 49 on the bottom surface 48 of the cap plate 25 into the groove 50 of the shaft 20, additionally urging the shaft 20 vertically downward to frictionally engage bottom face 52 against bottom face 54 of the channel 18. The bottom face and groove each provide a reacting face to prevent motion of the drive elements 12a, 12b and attached sockets 10a, 10b along the shaft 20. After completion of tightening of the fasteners, any preload induced in the sockets 10a, 10b is released by withdrawing the bolts 27 allowing the drive elements 12a, 12b play on the shaft 20. The torque reactor may then be removed from the fasteners. While shown in the embodiment as a triangular key and groove, key 49 and groove 50 may have alternative geometric cross sections. This embodiment requires additional vertical clearance over the prior embodiments in the use application for access to the bolts 27. The first and second embodiments may provide a lower profile in compact working spaces.
A fourth embodiment of the torque reactor is shown in FIGS. 4A-4C employing restraining elements having multiple features. For this embodiment, drive elements 56a and 56b are integral to sockets 10a, 10b extending as an upper portion of the sockets. Shaft 58 is slidably engaged through an aperture 60 in each of the drive elements 56a, 56b and is releasably secured with set screws 62 providing a first feature of the restraining element. In each socket 10a, 10b a removable bifurcated segment 64 is attached with a bolt 66 acting as a second feature of the restraining element. The bolt 66 is received through an aperture 68 in the segment 64 and secured in a threaded bore 70 in the socket as seen in FIG. 4C. In use, the segments 64 are secured in the sockets 10a, 10b by tightening bolts 66. The sockets 10a, 10b are then adjusted to a desired spacing to engage adjacent fasteners by sliding drive elements 56a, 56b along shaft 58 and securing the shaft with set screws 62. After torqueing of the fasteners if a preload has been induced, bolts 66 are loosened releasing the segments 64 to allow removal of the torque reactor from the fasteners. In an alternative form of this embodiment, the segments may extend into the drive elements and a single securing bolt may replace the set screw 62 and bolt 66 for engaging the shaft and mating the segment to the socket.
For the first three embodiment described herein a quadrilateral shaft is employed with the shaft of the fourth embodiment employs a hexagonal cross section. In alternative embodiments, any geometric cross section providing engaging surfaces for the restraining elements and the receiving channel or aperture.
A method for reacting torque during fastener installation using the embodiments disclosed herein is shown in FIG. 5 and described with respect to the embodiment of FIGS. 1A-1D as exemplary. Restraining elements, for example set screws 28, in drive elements 12a, 12b are released, step 502, and the drive elements 12a, 12b are laterally adjusted, step 504, on the shaft 20 to be equivalent to spacing of fasteners onto which sockets 10a, 10b are placed, step 506. As noted with respect to the first embodiment only one of the drive elements needs to be positionable but both are identified as moving for maximum flexibility in use. The restraining elements in drive elements 12a, 12b are then secured, step 508 constraining the shaft in the drive elements 12a, 12b. Torqueing of one of the fasteners is transmitted in associated socket 10a through the associated drive element 12a and shaft 20 to the other drive element 12b and socket 10b secured to the adjacent fastener employing the arm length of the shaft 20 between the drive elements 12a, 12b for mechanical advantage to react the torque, step 510. Upon completion of torqueing the fastener, the restraining elements are released, step 512, thereby allowing any preload established in the sockets 10a, 10b to be released, step 514. The sockets 10a, 10b may then be removed from the fasteners, step 516.
Embodiments of the disclosure may be employed in the context of an aircraft manufacturing and service method 600 (method 600) as shown in FIG. 6 and an aircraft 700 as shown in FIG. 7. During pre-production, the exemplary method 600 may include specification and design 604 of the aircraft 700 and material procurement 606. During production, component and subassembly manufacturing 608 and system integration 610 of the aircraft 700 takes place. Thereafter, the aircraft 700 may go through certification and delivery 612 in order to be placed in service 614. While in service by a customer, the aircraft 700 is scheduled for routine maintenance and service 616 (which may also include modification, reconfiguration, refurbishment, and so on).
Each of the processes of method 600 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of venders, subcontractors, and suppliers; and an operator may be without limitation an airline, leasing company, military entity, service organization, and the like.
As shown in FIG. 7, the aircraft 700 produced by the exemplary method 600 may include an airframe 718 with a plurality of systems 720 and an interior 722. Examples of high-level systems 720 include one or more of a propulsion system 724, an electrical system 726, a hydraulic system 728, an environmental system 730, and flight control system 732. Any number of other systems may also be included. Although an aerospace example is shown, the embodiments of the disclosure may be applied to other industries.
Apparatus and methods embodied herein and previously described may be employed during any one or more of the stages of the production and service method 600. For example, components or subassemblies corresponding to production process 608 may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft 700 is in service. In addition, one or more apparatus embodiments as described herein, method embodiments described herein, or a combination thereof may be utilized during the production stages 608 and 610, for example, by substantially expediting assembly of or reducing the cost of an aircraft 700. Similarly, one or more of apparatus embodiments, method embodiments, or a combination thereof may be utilized while the aircraft 700 is in service, for example and without limitation, to maintenance and service 616.
Having now described various embodiments of the disclosure in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present disclosure as defined in the following claims.
Patent Application
20170209992
