Patent Publication Number: US-10307897-B2

Title: Double socket telescopic torque reactor

Description:
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  10   a  and  10   b  are configured to engage a first fastener element and an adjacent fastener element. First and second drive elements  12   a  and  12   b  are provided to engage the sockets  10   a ,  10   b . For the embodiment shown the engagement is a square drive  14  received in a square relief  16  in each socket  10   a ,  10   b  as seen in  FIG. 1C . Those skilled in the art will recognize alternative drive configurations for the drive elements and sockets. Each drive element  12   a ,  12   b  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  12   a ,  12   b  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  12   a ,  12   b . 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  10   a ,  10   b . 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  12   a ,  12   b  longitudinally along the shaft  20  for repositioning and for relief of any preload induced by torque of fastener elements in the sockets  10   a ,  10   b . In use, the sockets  10   a ,  10   b  are engaged on the fastener elements, shown in the exemplary embodiment as fastener nuts  11   a ,  11   b  which engage fastener bolts  11   c ,  11   d  inserted through bores  8   a  and  8   b  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  12   a ,  12   b  and attached sockets  10   a ,  10   b  along the shaft  20 . After completion of tightening of the fasteners, for example with wrench  29 , any preload induced in the sockets  10   a ,  10   b  is released by withdrawing the set screws  28  allowing the drive elements  12   a ,  12   b  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  10   a ,  10   b  to receive the fastener element and cross section of the shaft  20  and resulting depth of drive elements  12   a ,  12   b  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  12   a ,  12   b . 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  12   a  in the released position and drive element  12   b  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  12   a ,  12   b . As in the first embodiment, after completion of tightening of the fasteners, any preload induced in the sockets  10   a ,  10   b  is released by rotating the cams  36  with the releasing face  40  adjacent the shaft  20  thereby allowing the drive elements  12   a ,  12   b  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  12   a ,  12   b  longitudinally along the shaft  20  for repositioning and for relief of any preload induced by torque of fastener elements in the sockets  10   a ,  10   b . 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  10   a ,  10   b  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  12   a ,  12   b  and attached sockets  10   a ,  10   b  along the shaft  20 . After completion of tightening of the fasteners, any preload induced in the sockets  10   a ,  10   b  is released by withdrawing the bolts  27  allowing the drive elements  12   a ,  12   b  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  56   a  and  56   b  are integral to sockets  10   a ,  10   b  extending as an upper portion of the sockets. Shaft  58  is slidably engaged through an aperture  60  in each of the drive elements  56   a ,  56   b  and is releasably secured with set screws  62  providing a first feature of the restraining element. In each socket  10   a ,  10   b  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  10   a ,  10   b  by tightening bolts  66 . The sockets  10   a ,  10   b  are then adjusted to a desired spacing to engage adjacent fasteners by sliding drive elements  56   a ,  56   b  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  12   a ,  12   b  are released, step  502 , and the drive elements  12   a ,  12   b  are laterally adjusted, step  504 , on the shaft  20  to be equivalent to spacing of fasteners onto which sockets  10   a ,  10   b  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  12   a ,  12   b  are then secured, step  508  constraining the shaft in the drive elements  12   a ,  12   b . Torqueing of one of the fasteners is transmitted in associated socket  10   a  through the associated drive element  12   a  and shaft  20  to the other drive element  12   b  and socket  10   b  secured to the adjacent fastener employing the arm length of the shaft  20  between the drive elements  12   a ,  12   b  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  10   a ,  10   b  to be released, step  514 . The sockets  10   a ,  10   b  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.