Patent Publication Number: US-7913593-B2

Title: Installation tool for a threaded object

Description:
GOVERNMENT RIGHTS 
     This invention was made with United States Government support under Contract Number N00024-03-C-6111 awarded by the Department of the Navy. The United States Government has certain rights in this invention. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field of the Invention 
     The invention is in the field of tools for installing threaded objects, such as threaded fasteners or explosive bolts. 
     2. Description of the Related Art 
     There is a continuing need to be able to install threaded fasteners or other threaded objects, such as explosive bolts, in locations where it can be very difficult to retrieve the threaded objects if they are dropped. Examples of such situations include installation of fasteners in missile bodies and for securing aircraft engines or other parts. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, a tool for gripping the head of a threaded object includes a sleeve having arms with lips on their inner surfaces. 
     According to another aspect of the invention, a tool for gripping the head of a threaded object includes a bit having a tip for engaging the head, and a sleeve surrounding the bit that holds the head against a tip of the bit prior to the threading operation and during at least part of the threading operation. 
     According to yet another aspect of the invention, a tool for installing a threaded object includes a sleeve that couples the head to a bit that is surrounded by a sleeve, wherein the sleeve automatically disengages from the threaded object during the threading operation. 
     According to still another aspect of the invention, a tool for gripping and installing a threaded object includes a bit and a sleeve surrounding the bit, wherein the bit and the sleeve are mechanically coupled together and able to translate relative to one another to a limited extent in a direction along a longitudinal axis of the tool. The sleeve and the bit may share the same longitudinal axis. 
     According to a further aspect of the invention, a tool includes: a bit having a tip for engaging a head of threaded object; and a sleeve surrounding the bit and mechanically coupled to the bit such that the sleeve relative to the bit in a direction parallel to a longitudinal axis of the bit. The sleeve includes multiple arms able to flex radially outward away from the bit. The at least some of the arms have respective lips protruding radially inward along inner surfaces of the at least some of the arms. 
     According to a still further aspect of the invention, a method of installing a threaded object in a threaded hole includes the steps of: securing the threaded object to a tool that includes a sleeve surrounding an inner implement, wherein the securing includes having a tip of the inner implement engage a head of the threaded object, and wherein the securing includes receiving a head of the threaded object in a socket defined by the sleeve; threading the threaded object into the threaded hole by turning the inner implement with the tip of the inner implement engaged with the head of the threaded object; and disengaging the sleeve from the threaded object as the threaded object is threaded into the threaded hole, wherein the disengaging occurs automatically during threading as the sleeve presses against material surrounding the threaded hole. 
     To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the annexed drawings, which are not necessarily to scale: 
         FIG. 1  is an exploded view of a tool in accordance with an embodiment of the present invention, and of a threaded object to be engaged by the tool; 
         FIG. 2  is a sectional view of a sleeve socket of the tool of  FIG. 1 ; 
         FIG. 3  is a detailed sectional view of the tip or free end region of one of the sleeve arms of the sleeve socket of  FIG. 2 ; 
         FIG. 4  is an oblique view showing a first step in use of the tool of  FIG. 1  to install a threaded object; 
         FIG. 5  is an oblique view showing a second step of the installation process; 
         FIG. 6  is an oblique view showing a third step of the installation process; 
         FIG. 7  is an oblique view showing a fourth step of the installation process; 
         FIG. 8  is an oblique view showing a fifth step of the installation process; and 
         FIG. 9  is an oblique view showing a sixth step of the installation process. 
     
    
    
     DETAILED DESCRIPTION 
     A tool for installing a threaded object includes a bit or inner implement that has a tip for engaging a head of the threaded object, and a sleeve surrounding the inner implement for securing the threaded object to the tool during the installation process. The sleeve includes plural arms at least some of which have inner lips that engage the head of the threaded object to hold the head against the tip. The inner lips are chamfered to facilitate engagement and disengagement between the sleeve and the head of the threaded object. The sleeve is able to translate to a limited extent relative to the inner implement, in order to pull back and disengage from the threaded object head as the threaded object is received into a threaded opening. 
       FIG. 1  shows an installation tool  10  that is used for securing and installing a threaded object  12 . The threaded object  12  may be an explosive bolt, a threaded fastener, or another type of threaded object. The installation tool  10  includes a bit or inner implement  16 , a sleeve socket  18 , and a pin  20 . When the tool  10  is assembled, the sleeve socket  18  surrounds the bit  16 . The pin  20  mechanically couples the bit  16  and the sleeve socket  18  together. The pin  20  passes through an elongate hole  22  in the sleeve  18 , and is press fit into a round hole  26  in the bit  16 . The bit  16  has a bit tip  28  that is configured to engage a head  30  of the threaded object  12 . In the illustrated embodiment the bit tip  28  engages a recess  32  in the threaded object head  30 . The bit tip  28  may have any of a variety of shapes, including a hex shape or a TORX or star shape. Alternatively, the bit tip  28  may engage the threaded object head  30  in other ways, such as by engaging outer surfaces of the threaded object head  30 . The bit tip  28  may have an engagement mechanism  34  on the end opposite the bit tip  28 , for engaging a driver, wrench, or other device, for turning the bit  16 . In the illustrated embodiment the engagement mechanism  34  includes a recess  36  that can be secured to another device. 
     The sleeve socket  18  has a sleeve body  40 , and plural sleeve arms  44  that extend longitudinally downward from the sleeve body  40 . The sleeve arms  44  define an opening or socket  46  for receiving the threaded object head  30 . The sleeve arms  44  may be axisymmetrically located about a common longitudinal axis  48  shared by the bit  16  and the sleeve socket  18 . The sleeve arms  44  are separated from one another by gaps or slots  50 . This allows the sleeve arms  44  to flex outward, so as to resiliently move outward to engage or disengage the threaded object head  30  and a washer  54  that is located on a shaft  56  of the threaded object  12 . The sleeve body  40  and the sleeve arms  44  may be all parts of a single monolithic piece of material that constitutes the sleeve  18 . The gaps or slots  50  may correspond to portions of material removed from the sleeve  18  by any of a variety of suitable processes, such as machining. 
     The elongate hole  22  allows translation of the sleeve  18  relative to the bit or inner implement  16 . This translation is in the longitudinal direction of the tool  10  (parallel to the longitudinal axis  48 ). This relative translation is utilized in the automatic disengagement of the sleeve  18  from the threaded object  12  as the threaded object  12  is installed into an internally-threaded hole. 
     The threaded object shaft  56  has a threaded end  60 . A base  62  is used for receiving portions of the threaded object shaft  56 , in a hole  66 , in order to facilitate engagement of the installation tool  10  on the head  30  of the threaded object  12 . 
     It will be appreciated that many alternatives are possible regarding the type of engagement between the bit or inner implement  16  and the sleeve socket  18 . Suitable lips on the inside of the sleeve body  40  may be used to provide limited relative translation between the sleeve socket  18  and the bit  16 , for instance. Other alternatives involve a protrusion either on the bit  16  or the sleeve  18  that engages a recess or slot of limited extent in the other member. 
     With reference now in addition to  FIGS. 2 and 3 , further details are now given of structure on the inside surfaces of the sleeve arms  44 . Inner arm surfaces  70  have respective sloped sections or stops  72 . The sloped sections  72  correspond in shape to the slope on the threaded object head  30 . The sloped section  72  may serve as a stop, preventing overinsertion of the head  30 , as well as providing better support to the threaded object  12  when the head  30  is engaged with and inside the sleeve  18 . It will be appreciated that the stop  72  may have a different shape corresponding to a different shape for the threaded object head  30  ( FIG. 1 ), or may alternatively be omitted altogether. 
     The arms  44  each have a lip  76  near a free end  78  of the arm  44 . The lip  76  is used to engage the head  30  or the washer  54 , and mechanically couple together the bit  16  and the threaded object  12 . The lip  76  is a protrusion extending radially inward from the arm inner surface  70 . The lip  76  has chamfered or sloped surfaces  84  and  86  in both longitudinal directions, both toward the arm free end  78  and away from the arm free end  78 . The chamfered or sloped surfaces  84  and  86  aid in engagement and disengagement of the sleeve  18  with the threaded object  12 . 
     The sleeve socket  18  may be made of flexible stainless steel, such as 17-4 stainless steel. Other types of steel may alternatively be used. In addition, other types of materials may be used for the sleeve socket  18 , such as aluminum or suitable plastics. 
     The sleeve arms  44  have a thinned or sloped tip portion  90  in the vicinity of the arm free end  78 . This sloped end they make for more flexibility in the parts of the arm  44  that are around the lips  76 . The sloped section or stop  72  may also function to provide increased rigidity to the arms  44  in the area of the arms  44  that surrounds the threaded object head  30 . 
     The illustrated embodiment shows the sleeve  18  with six sleeve arms  44 . It will be appreciated that a greater or lesser number of sleeve arms may be utilized. In addition, it will be appreciated that a wide variety of configurations of the sleeve arms may be used for engaging different threaded objects having different head configurations. For instance, it will be appreciated that the sleeve arms may be configured for engaging a threaded object having a hexagonal or square shape head. The sleeve arms for such an arrangement may be flat, rather than the curved arms illustrated in  FIGS. 1-3 . In connection with this it will be appreciated that the sleeve  18  may alternatively have a non-cylindrical cross section. 
       FIGS. 4-9  show the process used in installing the threaded object  12  using the tool  10 . In  FIG. 4  the threaded object  12  is installed in the base  62 . The threaded object head  30  and the washer  54  protrude out of the base  62 . 
       FIG. 5  illustrates the engagement of the tool  10  with the threaded object  12 . The tool  10  is pressed down onto an engagement with the threaded object head  30  ( FIG. 1 ). In doing so the bit tip of the bit or inner implement  16  is engaged with the recess  32  in the threaded object head  30 . The sleeve socket  18  is also brought into engagement with the threaded object head  30  and the washer  54 , with the head  30  and the washer  54  received in the socket or opening  46 . Either before or during the engagement of the bit tip  28  with the threaded object head  30 , the sleeve  18  is extended relative to the bit  16 . This involves moving the sleeve  18  downward as shown in  FIG. 5  until the pin  20  is at the upper most position within the elongate hole  22  (away from the sleeve arms  44 ). As this is done, and as the bit  16  engages the threaded object head  30 , the lips  76  of the sleeve arms  44  come into contact with portions of the threaded object head  30  and the washer  54 . This causes the sleeve arms  44  to resiliently deform outward, so as to get around the threaded object head  30  and the washer  54 . The chamfered or sloped surfaces  84  that face the free ends  78  of the sleeve arms  44  may aid in urging the sleeve arms  44  radially outward, away from the longitudinal axis  48  of the tool  10 . Once the lips  76  move longitudinally beyond the washer  54 , the sleeve arms  44  are free to resiliently snap back into place. At this point the threaded object head  30  and the washer  54  are fully within the sleeve  18 . The stop  72  may also provide a limit for the travel of the threaded object head  30  into the sleeve socket  18 . The presence of the lips  76  on the inner arm surfaces  70  prevents the threaded object head  30  from disengaging from the sleeve  18 , unless a sufficient force is provided so as to move the sleeve arms  44  radially outward again. 
     The elongate hole  22  is positioned and sized relative to the lips  76  such that when the threaded object head  30  and the washer  54  are within the sleeve  18 , the bit tip  28  is engaged with the recess  32  in the threaded object head  30 . Thus in the engaged position shown in  FIG. 5  the threaded object  12  is mechanically coupled to the tool  10 , and the bit tip  18  is engaged with the threaded object head  30  so as to be able to transmit torque to the threaded object  12 . 
     With the tool  10  and the threaded object  12  coupled together the tool  10  may be used to lift the threaded object  12  out of the base  62 , as is shown in  FIG. 6 . The threaded object  12  and the tool  10  are then moved toward a receiving object  100  having an internally-threaded hole  102  for receiving the threaded object  12 . The receiving object  100  may be any of a wide variety of objects that receive a threaded object for fastening or other purposes. It will be appreciated that it is advantageous to have the threaded object  12  mechanically coupled to the tool  10  as the threaded object  12  is brought over to the receiving object  100 . As discussed earlier, dropped objects such as explosive bolts or threaded fasteners may cause appreciable delay and expense, due to their need to be removed from sensitive areas. 
       FIG. 7  shows the threaded object  12  partially threaded into the threaded hole  102  in the receiving object  100 . Throughout most of the threading operation the threaded object head  30  remains coupled to the sleeve  18 . Since the mechanical coupling between the sleeve  18  and the threaded object  12  also maintains the bit tip  28  engaged in the threaded object head  30 , there is no need for separate engagement of the bit  16  and the threaded object  12 . Simple turning of the installation tool  10  is sufficient to assure turning of the threaded object  12 . 
     As the threading operation nears its conclusion the sleeve socket  18  and the sleeve arms  44  come into contact with a surface  104  of the receiving object  100 , as illustrated in  FIG. 8 . The free ends  78  of the sleeve arms  44  make contact with the receiving object surface  104 . This causes the sleeve  18  to translate laterally upward relative to the bit or inner implement  16 . In addition the chamfered or sloped surfaces  86  of the lip  76  come in contact with the washer  54 . (If the washer  54  was not present then the chamfered surface  84  would come into contact with the threaded object head  30 .) The contact between the sloped lip surfaces  84  and the washer  54  causes the sleeve arms  44  to be pushed radially outward. The sleeve arms  44  resiliently deform radially outward so as to be able to get around the washer  54  and the threaded object head  30 , which have a diameter that is larger than the space between the lips  76  of opposite of the sleeve arms  44 . As the threaded object  12  continues to be screwed into the threaded hole  102  the sleeve  18  automatically becomes disengaged from the threaded object  12 . Since the threaded object  12  is almost completely threaded into the threaded hole  102  at this point this disengagement is of no concern from the standpoint of the possibility of the threaded object  12  becoming loose or dropping into inaccessible areas. It will be appreciated that it is advantageous that the sleeve  18  automatically disengages itself from the threaded object head  30  as part of the process of screwing the threaded object  12  into the threaded hole  102 . 
       FIG. 9  shows the situation at the completion of the threading process. With the tool  10  automatically mechanically disengaged from the threaded object  12 , the tool  10  may be merely lifted off of the threaded object  12 . The threaded object  12  has now been fully installed into the receiving object  100 , with the threaded object  12  being secured against dropping at all times during the installation process. 
     The sleeve socket  18  may be configured for engaging only one particular type of threaded object  12 . The bit  16  may be permanently coupled to the sleeve  18 , though still allowing relative movement between the two. Alternatively, different types of bits and different configurations of sleeves may be utilized in a mix-and-match manner in order to produce tools capable of coupling with different types of threaded objects, for instance having different head configurations and/or requiring different types of engaging bit tips. 
     Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.