Patent Publication Number: US-8984990-B2

Title: Lockable grip wrench

Description:
This application claims the benefit of U.S. Provisional Application No. 61/621,635, filed 9 Apr. 2012, the entire disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to hand wrenches, such as for tightening or loosening fasteners. 
     Numerous wrenches are known in the art. For example, a conventional box end wrench typically has two faceted openings, one on each end, for receiving a faceted fastener, such as a conventional hexagonal nut. Such box end wrenches typically require that the wrench be repositioned numerous times to rotate the nut to the desired position, which is cumbersome. As such, ratcheting box end wrenches have been developed that allow for easier use. However, even ratcheting box end wrenches are designed for a specific size, or a very limited range of sizes, of nuts. Therefore, multiple ratcheting box end wrenches are required for jobs with multiple sizes of nuts. And, conventional ratcheting box end wrenches may be unsuited to some types of fasteners, such as TORX brand fasteners. 
     Other known wrenches include relatively pivoting handles and provide for the nut to be gripped by moving multiple jaw elements inward in response to closing together of the handles. For example, U.S. Pat. No. 2,787,925 shows such a wrench, sometimes referred to as a grip wrench. However, the Buchannan tool requires that the user manually hold the handles together against spreading when applying torque to the nut. As such, the torque applied to the fastener by the Buchannan tool may be limited by the user&#39;s grip strength, which may be insufficient in some situations. 
     Thus, while the prior art wrenches may be suitable for some situations, they may not be suitable for all situations. Accordingly, there remains a need for alternative wrenches, particularly variable-size wrenches that provide secure gripping. 
     SUMMARY 
     Described below are one or more embodiments of a wrench having a locking mechanism that is designed to work with workpieces that are sizes anywhere in a working size range of the wrench, and related methods. 
     In one or ore embodiments, a locking grip wrench is provided. The wrench includes first and second handles. The first handle has a first grip section and a first working section. The second handle has second grip section and a second working section. The second handle is rotatably mounted to the first handle such that the first and second working sections overlap and the first and second handles are rotatable relative to each other about a first axis. The wrench has a workpiece-receiving opening extending through the first and second handles and disposed about the first axis. The wrench has a plurality of jaw elements disposed about the first axis in spaced relation to each other and movable toward and away from the first axis. The jaw elements are movable toward and away from the first axis in response to movement of the first and second grip sections toward and away from each other, respectively. The wrench has a lock mechanism. The lock mechanism includes a lock element and an actuator. The lock element is movably disposed in the first handle. The actuator is mounted for rotational movement about the first axis and has a peripheral cam surface eccentrically disposed relative to the first axis and selectively engagable against a lock element. The wrench is configured such that a spacing between the jaw elements is variably controlled based on a rotational position of the actuator relative to the first axis. 
     In one or more embodiments, the locking grip wrench has first and second handles. The first handle has a first grip section and a first working section. The second handle has a second grip section and a second working section. The second handle is rotatably mounted to the first handle such that the first and second working sections overlap and the first and second handles are rotatable relative to each other about a first axis. The wrench has a workpiece-receiving opening extending through the first and second handles and peripherally surrounding the first axis. The first handle has a plurality of arcuate first guide slots disposed about the workpiece-receiving opening and outboard thereof. The first handle also has a first lock slot disposed in spaced relation to the workpiece-receiving opening. The second handle has a plurality of outwardly extending second guide slots oriented toward the workpiece-receiving opening. The second handle also has a second lock slot disposed in spaced relation to the workpiece-receiving opening. A plurality of jaw elements are disposed about the first axis in spaced relation to each other. The jaw elements are movable in the second guide slots toward and away from the first axis in response to movement of the first and second grip sections toward and away from each other, respectively, such that movement of the first and second grip sections toward each other causes the jaw elements to be displaced toward the first axis, while movement of the first and second grip sections away from each other causes the jaw elements to be displaced away from the first axis. The wrench includes a lock mechanism having a lock element and an actuator. The lock element is disposed generally parallel to the first axis and movably disposed in the first and second lock slots. The lock slots are distinct from the guide slots. The actuator is selectively engagable against the lock element at a plurality of positions. The wrench is configured such that a spacing between the jaw elements is variably controlled based on a position of the actuator. 
     In one or more embodiments, the locking grip wrench has first and second handles. The first handle has a first grip section and a first working section. The second handle has a second grip section and a second working section. The second handle is rotatably mounted to the first handle such that the first and second working sections overlap and the first and second handles are rotatable relative to each other about a first axis. A workpiece-receiving opening extends through the first and second handles with the first axis extending through the workpiece-receiving opening. A plurality of jaw elements are disposed about the first axis in spaced relation to each other and movable toward and away from the first axis. The jaw elements are movable toward and away from the first axis in response to movement of the first and second grip sections toward and away from each other, respectively. A lock mechanism includes a lock element and an actuator. The lock element is movably disposed in both a lock slot of the first handle and a lock slot of the second handle. The actuator is moveable relative to the lock element and the first and second handles, and the actuator has a cam surface. With the actuator in a locking position, the cam surface limits movement of the lock element toward the first axis to thereby limit movement of the jaw elements away from the from the first axis. 
     In one or more embodiments, a method of operating a manually-powered locking grip wrench includes moving grip sections of first and second handles toward each other to cause a plurality of jaw elements mounted in the handles to move toward an axis about which the first and second handles rotate relative to each other. The method also includes establishing a limit of movement of a plurality of jaw elements in a direction away from the axis by rotating a lock actuator about the axis to a locking position; wherein, in the locking position, a cam surface of the locking actuator is positioned in the path of a movable locking pin with the locking pin extending into both the first and second handles. The method may also include applying torque to a workpiece by rotating the wrench about the axis while the lock actuator is in the locking position. The rotating the lock actuator to the locking position may comprise abutting a cam surface against the locking pin. In some embodiments, the second handle comprises a lock slot along which the locking pin is slidable, and the rotating the lock actuator to the locking position comprises positioning the lock actuator so as to inhibit movement of the locking pin along the lock slot toward the axis beyond the cam surface. 
     The various aspects of the devices and methods discussed above may be used alone or in any combination. Further, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a wrench according to one embodiment. 
         FIG. 2  shows a front view of the wrench of  FIG. 1 , in the fully open and unlocked configuration. 
         FIG. 3  shows the wrench of  FIG. 2  with the left handle and lock actuator removed for clarity. 
         FIG. 4  shows the wrench of  FIG. 2  with the right handle, lock actuator, and some jaw elements removed for clarity. 
         FIG. 5  shows a perspective view of a jaw element. 
         FIG. 6  shows a front view of a lock mechanism, showing the actuator and the lock pin. 
         FIG. 7  shows a front view of the wrench of  FIG. 2 , in a partially closed and locked configuration. 
         FIG. 8  shows a front view of the wrench of  FIG. 2 , in a fully closed and locked configuration. 
     
    
    
     DETAILED DESCRIPTION 
     In one or more embodiments, the present application is directed to a wrench that includes a locking mechanism that provides variable locking positions and/or related methods. The wrench has handles that are rotatably connected such that a closing motion of the handles allows the wrench to grip workpieces as desired by moving a plurality of jaw elements inward toward the workplace. The locking mechanism advantageously allows the jaws and handles of the wrench to be locked precisely on any size workpiece within the working range of the wrench. For simplicity, a nut will be used as an illustrative workpiece in the discussion below; however, it should be understood that other fasteners, and indeed other workpieces, may alternatively be gripped by the wrench. 
     The wrench of  FIG. 1 , generally indicated at  10 , includes a right handle assembly  20 , a left handle assembly  40 , a plurality of jaw elements  60 , and a locking mechanism  70 . As further detailed in  FIGS. 2-3 , the right handle assembly  20  (sometimes referred to simply as the right handle) includes a grip section  24  toward one end and a working section  30  toward the opposing end. The head or working section  30  includes an opening  32  therethrough, which may be circular or otherwise in shape. For the illustrated embodiment, the opening  32  is peripherally disposed about an axis  34 . The working section  30  also includes a plurality of curved guide slots  36  which are disposed in spaced relation to opening  32 . The guide slots  36  advantageously have a consistent radius of curvature, both along a given guide slot  36  and from guide slot  36  to guide slot  36 . The working section  30  also includes a lock slot  38 , which is advantageously straight and disposed at a transverse angle to the grip section  24 . The right handle  20  is advantageously formed primarily of metal for strength, but the grip section  24  may optionally include an outer plastic grip element  25  for improved ergonomic feel. The working section  30  of the right handle  20  may be formed of a single unitary member, but is advantageously formed of an upper plate  21  and a lower plate  22  that are substantially identical and joined together by suitable means, such as by a plurality of spaced apart rivets  23 . 
     Referring to  FIG. 1 ,  FIG. 2 , and  FIG. 4 , the left handle assembly  40  (sometimes referred to simply as the left handle) is rotatably mounted to the right handle  20 , with relative rotation therebetween being about axis  34 . The left handle  40  includes a grip section  44  toward one end and a working section  50  toward the opposing end. The head or working section  50  includes a main opening  52  therethrough, which may be circular or otherwise in shape. For the illustrated embodiment, the main opening  52  is peripherally disposed about axis  34 , so that opening  32  and opening  52  overlap, forming opening  12 . The working section  50  also includes a plurality of guide slots  54  that open onto opening  52 . The guide slots  54  are disposed in spaced relation to each other, and are advantageously straight. The working section  50  also includes a lock slot  56 , which is advantageously straight and disposed generally parallel to the grip section  44 . Thus, lock slot  56  and lock slot  38  are disposed transversely to each other. In addition, the left handle  40  includes a plurality of curved clearance slots  57 , through which some of rivets  23  extend. Like the right handle  20 , the left handle  40  is advantageously formed primarily of metal for strength, but the grip section  44  may optionally include an outer plastic grip element  45  for improved ergonomic feel. The working section  50  of the left handle  40  may be formed of a single unitary member, but is advantageously formed of an upper plate  41  and a lower plate  42  that are substantially identical and joined together by suitable means, such as by rivets (not shown, hidden by grip element  45 ). 
     The jaw elements  60  are moveably disposed in the working sections  30 , 50  of handles. Referring to  FIG. 5 , the jaw elements  60  include a main body  62  and a guide element  68 . The main body  62  may be generally block-like, and is slidably disposed in the corresponding slot  54 . The inward tip  64  of the main body  62  may be flat or may have another profile, such as rounded, as is desired. The guide elements  68  may be formed by a suitable pin that is fixed to extend through the main body. The pin  68  advantageously has a round cross-section, although other suitable shapes may alternatively be employed. The pin  68  is advantageously disposed perpendicular to the longitudinal axis  66  of the main body  62 , and advantageously extends out beyond the main body  62  in both directions parallel to axis  34 . Travel of the pin  68  in the corresponding guide slot(s)  36  controls the in/out movement of jaw element  60 , and thus the location of the jaw element  60  relative to axis  34 . Forces generated by moving the grip sections  24 , 44  of handles  20 , 40  toward or away from each other are transmitted to the bodies  62  via the interaction of pins  68  and slots  36 , and bodies  62  and slots  54 , to move the jaw elements  60  toward or away from axis  34 . 
     Referring to  FIG. 6 , the locking mechanism  70  includes an actuator  72  and a locking element  78 . The locking element  78  is slidably disposed in both lock slot  38  and lock slot  56 . The locking element  78  is typically a metal pin, and is therefore sometimes referred to as the locking pin. The actuator  72  is rotatably mounted to the wrench  10  for rotation about axis  34 . The actuator  72  advantageously takes the form of a ring having an outer cam surface  74 . The cam surface  74  is eccentrically disposed relative to axis  34  so that the various portions of cam surface  74  extend outward varying distances from axis  34 . In addition, the actuator  72  may include suitable finger engaging features  76  (e.g., a scalloped outer surface, knurling, etc.) disposed generally opposite the cam surface  74 . The actuator  72  is rotatable about axis  34  between an unlocked position ( FIG. 2 ) and a plurality of locked positions ( FIGS. 7-8 ). The actuator  72  is disposed outboard of the outermost portion of guide slots  54  and the corresponding jaw elements  60  (and any relevant rivets  23 ), so that rotation of the actuator  72 , at least in the unlocking direction, is not inhibited. As explained further below, the actuator  72 , in a locking position, defines a limit of inward movement of the locking pin  78  along lock slot  56  toward axis  34 , and this limit may be variably set based on the rotational position of the actuator  72 . Further, in the illustrated embodiment, the actuator  72  is disposed both between the grip section  24  and axis  34  and opposite grip section  24  relative to axis  34 , in both the unlocked and the locked positions. 
     The wrench  10  may grip the nut by placing the nut in opening  12 , and then squeezing the grip sections  24 , 44  toward each other. As the handles  20 , 40  rotate about axis  34 , the working sections  30 , 50  of the handles  20 , 40  are rotated relative to each other about axis  34 . This rotation causes the pins  68  of jaw elements  60  to travel in the arcuate guide slots  36 , which in turn causes the bodies  62  of the jaw elements  60  to slide inward along slots  52 . Thus, the jaw elements  60  are displaced inward when the grip sections  24 , 44  of the handles  20 , 40  are rotated toward each other. The inward displacement of the jaw elements  60  brings the tips  64  of the jaw elements  60  into contact with the corresponding facets of the nut&#39;s outer surface, thereby gripping the nut. Note that there are advantageously six jaw elements  60 , disposed at regular 60° intervals about axis  34 , so that each jaw element  60  presses against a corresponding facet of a conventional hexagonal nut. If gripping the nut to tighten it on a threaded rod, the nut is then turned, and the handles  20 , 40  released. An optional spring  39  biases the handles  20 , 40  so that the grip sections  24 , 44  are spread apart. If additional tightening is needed, the handles  20 , 40  are again squeezed, and additional torque applied. 
     In many situations, a user&#39;s grip strength is sufficient to hold the handles  20 , 40  together (toward the closed configuration with the jaw elements  60  displaced inward) during the tightening. However, in some situations, the handles  20 , 40  may tend to open despite the user&#39;s grip. To counter this, the actuator  72  of the locking mechanism  70  may be rotated (counter-clockwise in  FIG. 2 ) to a locking position ( FIG. 7 ) when the wrench  10  is gripping the nut, but before significant torque is applied. The actuator  72  is rotated until the cam surface  74  abuts the locking pin  78 . With this engagement, the locking pin  78  is prevented from moving inward toward the axis  34 . Due the interaction of the locking pin  78  and lock slots  38 , 56  this means that the handles  20 , 40  are prevented from moving outward beyond this point of engagement. Note that the handles  20 , 40  may still be moved inward if there were not a nut abutting the jaw elements  60 . Thus, the wrench  10  is locked against opening by the locking mechanism  70 , not by the user&#39;s grip strength. The user may then pull on the handles  20 , 40  in the desired direction to apply the torque to the nut. Note that with the wrench  10  in a locked configuration, the torque can be applied in either direction. To open the wrench  10 , the lock actuator  72  is simply rotated in the opposite direction, thereby allowing the jaw elements  60  to open further. 
     In the locked configuration ( FIG. 7 ), the jaw elements  60  are prevented from moving outward more than a maximum amount. That is, a distance D from the tip  64  of a given jaw element  60  to the axis  34  is limited to a maximum amount set by the rotational position of the actuator  72 . Thus, with the actuator  72  in the open/unlocked rotational position ( FIG. 2 ), the maximum distance from the jaw element  60  to axis  34  is X. Note that for symmetrically disposed jaw elements  60 , this means that the maximum distance between jaw elements  60  is 2X, and for non-symmetrically disposed jaw elements  60  the maximum distance is ≦2X. With the actuator  72  rotated to a locked position, the maximum distance is Y, which is less than X. Further, due to the contour of cam surface  74 , relative to axis  34 , the distance limit is variably selectable by the user. Thus, with the wrench in a further locked configuration (such as fully closed configuration of  FIG. 8 ) where actuator  72  further rotated, the maximum distance may be Z, which is less than Y. Because the distance limit is related to the travel of locking pin  78  along lock slot  36 , suitable size indicia may advantageously be included proximate lock slot  36 , so that the user may easily see the selected maximum size. 
     The discussion above has been in the context of the wrench  10  having six jaw elements  60  disposed at regular intervals. Such an arrangement is believed advantageous. However, the wrench  10  may include an even number or an odd number of jaw elements  60 , as is desired. Thus, in an un-illustrated embodiment, the wrench includes three jaw elements  60 , spaced from each other at 120° intervals about axis  34 . Further, the jaw elements  60  may be regularly spaced or irregularly spaced about axis  34 . 
     The disclosure of any U.S. patents or patent application publications mentioned above are incorporated herein in their entirety. 
     The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.