Abstract:
A ratchet wrench for turning threaded fasteners, particularly fasteners threaded on a stud or pipe located in areas of limited or obstructed access to the fastener. The wrench is operated remotely at an end of the wrench away from a fastener engagement portion. The wrench includes a side mounted actuator assembly which allows a moveable jaw to open and close around the fastener. A closing bias force is maintained on the movable upper jaw by a spring included in the actuator assembly. The closing bias force allows a fastener to be held in position for rotation and when exceeded, allows the movable upper jaw to ratchet around the fastener. The engagement portion of the wrench may be configured with either a hexagonal or dodecahedral shaped opening. When operatively engaged with the fastener, the wrench fully encompasses the fastener to limit slippage.

Description:
FIELD OF INVENTION  
         [0001]    The invention relates to a ratchet wrench for rotating threaded fasteners and in particular threaded fasteners located in areas having obstructions or limited access to the fastener to be rotated.  
         BACKGROUND  
         [0002]    In the relevant art, various hand tools or wrenches are provided for turning of fasteners such as threaded nuts, bolts or pipes. In particular, those wrenches associated with turning a nut or bolt generally rely on a hexagonal shaped head and may be characterized as an open-end wrench which generally engages the fastener on two parallel surfaces of the hexagon head, or a closed-end wrench which engages the fastener on all six corners of the hexagon. The closed-end wrench may have either a hexagonal or dodecahedral configuration. The hexagonal configuration has the advantages of being the same hexagonal shape as the fastener which provides the greatest contact surface areas for transferring rotational forces from the wrench to the fastener, thus reducing the likelihood of slippage from the fastener. However, the hexagonal configuration limits the available engagement geometries with the fastener which is particularly troublesome when attempting to rotate a fastener in a tight or obstructed location. A dodecahedral configuration provides twelve angled surfaces for engagement with the fastener, thus improving the available engagement geometries but reduces the contact surface areas with the fastener allowing for more likelihood of slippage from the fastener.  
           [0003]    A further characteristic of the open-end wrench is that it may engage the fastener from either the side or top. However, the closed-end wrench must engage the fastener from the top. If the fastener is on a long continuous shaft, such as a long bolt, stud, or a length of threaded pipe, access to the top of the fastener is restricted and the closed-end wrench may be unable to engage the fastener, or in the alternative, engaging the fastener may involve moving the wrench such a distance along the stud or pipe as to make its use impractical. In these cases, the open-end wrench has an advantage in accessing the fastener. The open-end wrench however has the disadvantage of limited engagement of the fastener, and due to varying tolerances in fastener size, it is known for open-end wrenches to damage the corners of the hexagon, and perhaps cause injury to the wrench user, by “slipping,” especially if the fastener is difficult to turn.  
           [0004]    A variation of the closed-end wrench, commonly called a flare nut wrench, is essentially a closed-end wrench with a small opening in the end that allows slipping the wrench over tubing or a threaded stud to engage the fastener. Due to the opening, these wrenches can slip and cause damage to the fastener or injure the wrench user. In addition, flare nut wrenches require clearances around the fastener to allow for positioning of the wrench with the fastener which limits the usefulness of the flare nut wrench in tight or obstructed locations.  
           [0005]    Several inventions have attempted to combine the complete fastener engagement advantages of the closed-end wrench with the side engagement advantages of the open-end wrench. U.S. Pat. No. 2,758,493 (Goldwater) teaches a reversible ratchet wrench that engages a fastener on the side and provides a six point engagement of the fastener.  
           [0006]    U.S. Pat. No. 5,113,726 (Ethridge) teaches a pipe fastener tool that also provides a side six point fastener engagement. U.S. Pat. No. 6,263,765 (McCamley) shows another wrench capable of side six point fastener engagement. U.S. Pat. No. 6,279,427 (Francis) shows a hydraulically operated torque wrench designed for side twelve point fastener engagement.  
           [0007]    Each of these inventions provides a solution to turning a fastener on a continuous shaft that is useful in some applications. However, all of these inventions require manipulation of the head of the wrench mechanism at a location in proximity to the fastener, and therefore cannot be used in situations where access to the fastener is so restricted that the fastener is not readily accessible to the hands of the user.  
           [0008]    Therefore, what is highly desirable is a simple tool whose actuator assembly is operated remotely from the fastener in situations where access to the fastener on a continuous stud, bolt or pipe is restricted and further includes a narrow profile so that it may be used in tight or obstructed locations.  
         SUMMARY  
       Objects and Advantages  
         [0009]    One object of this invention is to provide a tool to turn a fastener that engages fasteners that are on a threaded stud or pipe.  
           [0010]    A second object of this invention is to provide a tool to turn a fastener that provides either a six or twelve point engagement of the fastener.  
           [0011]    A third object of this invention is to provide a tool to turn a fastener that engages a fastener in a restricted access location where the fastener cannot be reached by the user&#39;s hands.  
           [0012]    A fourth object of this invention is to provide a tool to turn a fastener that will access the fastener in a confined space of approximately the width of the fastener.  
           [0013]    A fifth object of this invention is to provide a tool to turn a fastener that is adaptable to a variety of turning aids.  
           [0014]    A sixth object of this invention is to provide a tool to turn a fastener that is sturdily and simply constructed so as to provide long tool life.  
           [0015]    A seventh object of this invention is to provide a tool to turn a fastener that is economical to manufacture.  
           [0016]    The invention comprises a ratchet wrench for turning a fastener in a tight or obstructed location. The wrench is manufactured to have a narrow profile equal to or less than that of a fastener in which the wrench is intended to be used upon. The narrow profile allows the wrench to be used in locations having restricted access or obstructions.  
           [0017]    The wrench includes a fixed jaw which is incorporated into a front end of a body of the wrench. Another movable upper jaw is pivotally attached to the body of the wrench and is further coupled to an actuator assembly. The actuator assembly is operable from a position away from the movable and fixed jaws. The movable and fixed jaws are arranged in opposition and define between themselves a substantially equal regular polygon shaped opening for engaging the fastener. The regular polygon shaped opening may be in the form of a hexagon or dodecahedron. The body of the wrench includes a receptacle for attaching a handle such as a breaker bar, standard ratchet wrench or extension bar. In one embodiment of the invention, the handle is attached perpendicular to the body of the wrench. In another embodiment of the invention the handle is attached in parallel to the body of the wrench.  
           [0018]    In both embodiments of the invention, the drive receptacle is situated along a longitudinal center axis of the body of the wrench.  
           [0019]    The wrench includes an opening side for situating the fastener between the movable and fixed jaws which is approximately centered along one side of the regular polygon shaped opening. A pivoting side is provided for attaching the movable upper jaw to the wrench body and is positioned on the opposite side of the regular polygon shaped opening in parallel to the opening side. The movable upper jaw is pivotally attached to the body of the wrench with a fastener means such as a pin, rivet, or bolt.  
           [0020]    An actuator assembly is provided for operating the wrench remotely, away from the movable and fixed jaws and includes a guide extending laterally from the pivoting side for slideably maintaining the actuator shaft adjacent to and generally in parallel with the pivoting side. A second pivotal fastener is provided for pivotally fastening the actuator shaft to the movable upper jaw. The actuator shaft is pivotally attached to the movable upper jaw with a fastener means such as a pin, rivet, or bolt.  
           [0021]    The actuator shaft provides the means for slideably transmitting an opening and a closing force to the movable upper jaw during operation. A coil or torsion spring coupled to the actuator shaft is used to provide a closing bias force to the movable upper jaw. The closing force bias may be adjusted by moving a spring stop longitudinally along the actuator shaft in order to obtain a desired closing bias force. The closing bias force is intended to provide sufficient force to allow an user to tighten a fastener until snug against another surface. If the closing bias force is exceeded, the movable upper jaw is allowed to perform a ratcheting action.  
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0022]    [0022]FIG. 1—is a top view of the invention illustrating a first embodiment.  
         [0023]    [0023]FIG. 1A—is a second top view of the invention illustrating a second embodiment.  
         [0024]    [0024]FIG. 1B—is a third top view of the invention illustrating a third embodiment.  
         [0025]    [0025]FIG. 2—is a first side view of the invention.  
         [0026]    [0026]FIG. 3—is a second side view of the invention with a movable upper jaw in an open position.  
         [0027]    [0027]FIG. 4—is the second side view of the invention with the movable upper jaw in a closed position.  
         [0028]    [0028]FIG. 5—is a top view of the invention shown with the movable upper jaw in an open position.  
         [0029]    [0029]FIG. 6—is a perspective view of the invention showing the wrench engaged with a fastener installed on a vertical threaded stud.  
         [0030]    [0030]FIG. 7—is another perspective view of the invention showing the wrench engaged with a fastener between interfering objects. 
     
    
     DETAILED DESCRIPTION  
       [0031]    Various embodiments of the ratchet wrench invention are shown in FIGS. 1 through 7. The invention includes a means of fastener engagement and turning in a tight or obstructed location. This capability is useful where the fastener is threaded on a stud, pipe or bolt that either continues beyond the area of access or is located between interfering structures. The wrench engages and turns fasteners with restricted access, even when the fastener location is not accessible to a user&#39;s hands.  
         [0032]    [0032]FIG. 1 depicts a top view of the assembled wrench which comprises a movable upper jaw  70  having an upper engagement surface  76  and an upper clearance surface  78 . The movable upper jaw  70  is attached to a body  50  of the wrench at a first pivot point  72  and to an actuator shaft  80  at a second pivot point  74 . The pivot points  72 ,  74  each include a pivotable fastener means such as a pin, rivet or bolt and are located on a pivoting side of the body  50  of the wrench.  
         [0033]    The body  50  of the wrench includes an opposing lower fixed jaw  56  incorporated into a front end of the body  50  of the wrench and a lower clearance surface  54  associated with the lower fixed jaw  56 . The upper and lower clearance surfaces  78 ,  54  provides the clearance during motion of the clamp over the fastener to allow final engagement of the fastener by the wrench. The movable upper jaw  70  and lower fixed jaw  56  define substantially and evenly between themselves a hexagonal opening  75  for engaging a hexagonal fastener. When operatively engaged with a fastener the movable upper jaw  70  and lower fixed jaw  56  fully encompass the fastener.  
         [0034]    The body  50  of the wrench further includes a drive receptacle  60  where the drive receptacle  60  for attaching a drive handle is provided along a longitudinal center axis and near a rear end of the body  50 . In this embodiment of the invention, the handle is attached perpendicular to the longitudinal center axis of the body  50  of the wrench.  
         [0035]    A guide  52  is provided on the same side of the wrench body as the pivot points  72 ,  74 . The guide  52  maintains the actuator shaft  80  in a generally parallel position in relation to the pivot side of the body  50  of the wrench and also serves as a fixed lower spring retention stop for a spring  92 . An actuator assembly is shown and includes the actuator shaft  80  pivotally coupled to the movable upper jaw  70 , the spring  92  and an upper spring retention stop  94 . The spring  92  is coaxially placed over the actuator shaft  80  and rests against one side of the guide  52 . The upper spring retention stop  94  is used to maintain the spring  92  in a somewhat compressed position to provide a closing bias force on the movable upper jaw  70  and includes a fastener  96  such as a bolt, pin or setscrew, to lock the upper spring retention stop  96  into a position along the actuator shaft  80 . The closing bias force may be varied by adjustment of the upper spring retention stop  94  as needed to provide the desired closing force on the movable upper jaw  70 . A lever  82  is provided on a lower end of the actuator shaft  80  to allow a user to open and close the movable upper jaw. The lever  82  is attached to the lower end of the actuator shaft  80  by way of a lever fastener  98  such as a bolt, pin or setscrew. The actuator assembly is remotely operated from the pivoting side by applying force to the lever  82 .  
         [0036]    Referring to FIG. 1A, an alternate embodiment of the invention is shown where the drive receptacle  60 A for attaching the drive handle is provided along the longitudinal center axis and at a rear end of the body  50  of the wrench. In this embodiment of the invention, the handle is attached in parallel to the longitudinal center axis of the body  50  of the wrench.  
         [0037]    Referring to FIG. 1B, another embodiment of the invention is shown where the movable upper jaw  70 A, upper engagement surface  76 A, upper clearance surface  78 A., lower clearance surface  54 A and lower fixed jaw  56 A define substantially evenly between themselves a dodecahedral opening  75 A for engaging a hexagonal fastener. The dodecahedral arrangement improves the available engagement geometries when using the wrench in a limited or obstructed location.  
         [0038]    In FIG. 2, a side view of the invention depicting the relative position of the actuator assembly  80 ,  92 ,  94 ,  96 ,  98  on the pivoting side  72 ,  74  of the body  50  of the wrench. The wrench has a narrow profile which allows its use in locations having limited clearances, obstructions and/or interfering surfaces. The narrow profile is sized to be less than or equal to the size of fastener. It is envisioned by the inventor that several different sized profiles and/or fasteners will be manufactured. In one embodiment of the invention, the wrench is constructed from a tool grade steel. In another embodiment of the invention, the wrench is constructed from a high impact plastic.  
         [0039]    In FIG. 3, another side view of the invention which depicts the movable upper jaw  70  in an open position is shown when viewed from the opening side of the body  50  of the wrench. The upper and lower clearance surfaces  78 ,  54  are depicted along with the pivot point  72  in which the movable upper jaw  70  is attached with the fastener to the body  50  of the wrench. The movable upper jaw  70  fits over a narrowed extension  58  of the wrench body  50  which allows for a uniform dimension of the wrench in the narrow profile plane. The drive receptacle  60  is provided for attaching a handle to the body  50  of the wrench.  
         [0040]    In FIG. 4, a third side view of the invention which depicts the movable upper jaw  70  in a closed position is shown when viewed from the opening side of the body  50  of the wrench. The movable upper jaw  70  is shown in a closed position which contacts the lower fixed jaw  56  incorporated into the body  50  of the wrench. The movable upper jaw  70  aligns with the fixed lower fixed jaw  56  substantially in parallel with respect to each other. The drive receptacle  60  is provided for attaching a handle to the body  50  of the wrench.  
         [0041]    Referring to FIG. 5, the movable upper jaw  70  can be moved to an open position by sliding the actuator shaft  80  in a direction directly opposite from the movable upper jaw  70 . Likewise, the movable upper jaw  70  can be moved to a closed position by sliding the actuator shaft  80  in the direction directly toward the movable upper jaw. Moving the actuator shaft  80  toward the open position also compresses the spring  92 . The spring  92  is sized to maintain a closing bias force on the movable upper jaw  70  even when the movable upper jaw  70  is in the fully closed position. The closing bias force maintains engagement of the movable upper jaw  70  with the fastener. Exceeding of the closing bias force, allows the movable upper jaw  70  to provide a ratcheting action. The drive receptacle  60  is provided for attaching a handle to the body  50  of the wrench.  
         [0042]    In FIG. 6, an operation of the invention is shown where the wrench is used to turn a fastener  105  installed on a threaded stud  100 . The operation begins with selecting a wrench to match the size fastener to be turned. The selected wrench is placed in the open position by holding the body  50  of the wrench and applying a opening force on the actuator shaft  80  using the lever  82 . The opening force causes the movable upper jaw to rotate in the opening direction. The wrench is then placed in the position shown in FIG. 5, where the movable upper jaw  70  is opened sufficiently to allow placement of the upper and lower engagement surfaces  56 ,  76  around the fastener.  
         [0043]    The wrench is oriented around the fastener such that the desired direction of rotation of the fastener will be towards the opening side as shown in FIG. 6. The movable upper jaw  70  is then closed around the fastener by either applying a pushing force to the actuator shaft  80  or allowing the closing bias force provided by the spring  92  to position the movable upper jaw around the fastener. This movement will place the wrench approximately in the position shown in FIG. 6. The wrench may now be rotated by placing a drive handle  62  in the drive receptacle  60  and applying force in the direction shown in FIG. 6.  
         [0044]    In FIG. 7, another operation of the invention is shown where the wrench is used to turn a fastener  130  installed between interfering surfaces  125 ,  135 . The narrow profile of the wrench allows access to the fastener  130  installed on a bolt  115 . The remote actuator assembly  80 ,  82 ,  92   94 ,  98  allows positioning of the wrench to engage and tighten the fastener  130  until snug against the opposing surface  125  of the flange. The closing bias force provided by the spring  92  on the movable upper jaw  70 , provides a ratcheting action of the movable upper jaw  70  in the tight space available between the interfering surfaces  125 ,  130 , allowing turning of the fastener. The final torque to hold the vertical pipe  115  is applied to an upper fastener  120 . As described above, the wrench is rotated by placing a drive handle  62  in the drive receptacle  60  and applying force in the direction shown in FIG. 7.  
         [0045]    The foregoing described embodiments of the invention are provided as illustrations and descriptions. They are not intended to limit the invention to precise form described. Other variations and embodiments are possible in light of above teachings, and it is not intended that this Detailed Description limit the scope of invention, but rather by the Claims following herein.