Abstract:
The adjustable wrench has two wrench elements each having a jaw portion and a body portion, each body portion having angled tongues and grooves, slideably mounted opposite one another with the jaw portions opposing each other. Between the two body portions is an actuator having two sides. Each side has angled tongues and grooves corresponding to and slideably engaging the angled tongues and grooves of each of the body portions. The actuator moves along a longitudinal axis of the handle thereby urging the wrench elements and jaws towards and away from one another depending on the direction of movement of the actuator, by interaction of the inclined grooves, acting as wedges using the inclined plane principle.

Description:
REFERENCE TO RELATED APPLICATION 
     This application is a formal application based on and claiming the benefit of provisional application No. 60/552,201, filed Mar. 12, 2004. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates generally to hand tools. More particularly, the invention relates to adjustable wrenches. 
     A common adjustable wrench in the prior art has a static jaw and a movable jaw on a screw thread. Rotating the screw slides the movable jaw across the wrench, allowing a user to adjust the space between the jaws to the required size bolt for tightening or loosening. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved adjustable wrench. 
     In a first aspect, the invention provides an adjustable wrench having two wrench elements each having a jaw portion and a body portion, each body portion having angled grooves, slideably mounted opposite one another with the jaw portions opposing each other. Between the two body portions is an actuator having two sides. Each side has angled grooves corresponding to and slideably engaging the angled grooves of each of the body portions. The actuator moves along a longitudinal axis of the handle thereby urging the wrench elements transversely across the cavity of the handle, and thereby moving the jaws towards and away from one another depending on the direction of movement of the actuator, by interaction of the inclined grooves, acting as wedges using the inclined plane principle. 
     In a further embodiment, the wrench has a similar mechanism provided at the other end of the wrench, preferably but not necessarily connected to the same actuator such that when the actuator is moved, the jaws at both ends move. The jaws at one end preferably cover a different range of sizes from the range of sizes available at the other end. 
     Other aspects and features of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention, in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: 
         FIG. 1  is an isometric view of the wrench with the jaws in the open position; 
         FIG. 2  is an isometric view of the wrench with the jaws in the closed position; 
         FIG. 3  is an exploded view of the wrench; 
         FIG. 4  is an isometric view of one side of the wrench without a first handle piece with the jaws in the closed position; 
         FIG. 5  is an isometric view of one side of the wrench without a first handle piece with the jaws in the open position; 
         FIG. 6  is an exploded view of an actuator, a button and a wrench element; 
         FIG. 7  is an isometric view of the first handle piece; 
         FIG. 8  is an isometric view of the second handle piece; 
         FIG. 9A  is a view of one side of a wrench element; 
         FIG. 9B  is a view of the other side of a wrench element; 
         FIG. 10  is an isometric view of the actuator plate; 
         FIG. 11  is a view of engaging side of the slider; 
         FIG. 12  is a view of the spring side of the slider; and 
         FIG. 13  is an isometric view of the wrench element with a gripping jaw body portion. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is an isometric view of the wrench with the jaws in the open position.  FIG. 2  shows the wrench in a similar view with the jaws in the closed position. The wrench has a handle  2  in two pieces  4 ,  6 , two wrench elements  3  having jaw portions  8  that protrude from the handle  2 , and a slideable button  10  on the handle that opens or closes the jaws  8  when the button is slid up or down the handle. 
       FIG. 3  is an exploded view of the wrench. A cavity  7  between the handle pieces  4 ,  6  holds body portions  9  of the wrench elements  3 . The surface of each body portion has angled grooves, on an angle from the longitudinal axis  5  of the wrench. Each body portion  9  is smaller in width than the width of the cavity  7  and has an oblong hole  12 . The oblong hole  12  is engaged by a protrusion  14  in a first handle piece  4  such that body portion  9  may slide along width of the handle  2 , but is restricted in movement along the longitudinal axis  5  of the handle. The protrusion  14  has a threaded hole which aligns with a hole  16  in the second handle piece  6 , to receive a bolt or screw (not shown) to secure the handle pieces together. Another protrusion  30  and hole  32  for a fastener (not shown) may be provided in the handle pieces to add stability to the wrench when assembled. The protrusions  14 ,  30  may be on the second handle piece  6  and the corresponding hole  16 ,  32  may be on the first handle piece  4 , alternatively. Any other suitable means may be used to secure the handles pieces to each other, or to assist. For example, the edges of the handles may have complementary dovetailing or the like, so that one handle piece slides on the other, the fastener(s) then merely preventing sliding the handle pieces apart. 
     The body portions  9  of the wrench elements  3  are positioned in the handle cavity  7  in reverse to one another, such that the inclined surfaces of the body portions face one another and the jaws  8  are reversed. Preferably, for ease and economy of manufacturing, the wrench elements are identical to each other. 
     Between the body portions is an actuator  20 . The actuator  20  conveniently may be assembled from two pieces, namely an actuator plate  22  and a slider  24 , rather than being in one piece. The actuator plate  22  has inclined grooves on each of its sides, which correspond to and engage the inclined grooves of the body portions  9 . Preferably, it is identical on each side (i.e.  FIG. 10  would appear the same regardless of which side of the actuator was being viewed). The actuator plate is connected to the slider  24 , for example by a post  60  engaging a hole  61  in the actuator plate (see  FIG. 6 ). The slider  24  has strips of teeth  34  to engage a series of stops  28  in the cavity  7  of the second handle piece  6 , shown in  FIG. 5  and  FIG. 8 , fixing the slider  24  and thereby the actuator plate  22  in positions along the longitudinal axis  5  of the handle. The slider  24  is held to the stops in the second handle by at least one biasing spring  26 . The biasing spring fits into the slider on the opposite side of the strips of teeth  34  shown in  FIG. 12 . The slider  24  is engaged by the button  10  on the outside of the second handle piece  6  through an elongated slot  27  in the second handle piece  6 . While the button  10  moves along the longitudinal axis  5  of the handle in the slot  27 , the slider  24  similarly moves along the cavity  7  of the handle. As the slider moves, the teeth  34  engage the stops  28  as it moves. Pressing the button  10  down into the handle releases the slider  24  from the stop and allows the slider  24  to move. The slider  24 , being connected to the actuator plate  22 , pushes or pulls the actuator plate  22  along the cavity  7 . As the actuator plate  22  moves along the longitudinal axis  5  of the handle, the inclined surfaces of the plate  22  engage the respective corresponding inclined surfaces of the body portions  9 . The wedge-like movement of the actuator plate  22  against the body portions  9  causes the wrench elements  3  to be urged together or apart depending on the direction of movement of the plate  22 . Because the wrench elements  3  are restricted in their movements in the direction of the longitudinal axis  5  of the handle, the wrench elements only move in the direction perpendicular to this axis  5 . 
     In the preferred embodiment, the inclined surfaces of the body portions  9  and the actuator plate  22  have a plurality of angled grooves  40  and corresponding angled tongues  42  as seen in  FIGS. 9 and 10 . The angled tongues  42  slideably fit in the angled grooves  40 . An alternative to this may be a single angled groove and a corresponding projection in the respective surfaces (not shown). 
     In the preferred embodiment, the grooves are angled from the axis  5  at an angle of substantially less than 45 degrees, for example approximately 10–12 degrees in the preferred embodiment. Obviously this angle can be varied as desired. However, such a relatively small angle has several advantages. The main advantage is that it is easy to move the slider due to the mechanical advantage which results. Conversely, it is difficult to dislodge the jaws from any given position for the same reason, i.e. the jaws in effect are locked in any position they are set to. The teeth  34  which lock the slider in place thus to not bear any significant load; the load is born by the grooves. Thus it should be noted that, depending on the angle and the maximum torque intended to be applied by the wrench, the teeth may not be strictly necessary; they merely provide a convenient means of setting the jaws to a desired spacing. Thus the slider may have an arrow or other such marking, and the handle may corresponding markings to indicate different jaw spacings (metric, English units, or both). 
     In another alternative embodiment (not shown), the same mechanism is provided at the other end of the handle and preferably but not necessarily is connected to the same actuator and button, such that when the button is moved, at one end of the handle the jaws are opening, while at the other end, the jaws are also moving (closing or opening, depending on which direction the grooves are angled away from the tool axis. 
     In a further alternative, shown in  FIG. 13 , the wrench element  3  is provided with a removable pivotable gripping jaw body portion  50 . The surface  51  of the jaw body portion is corrugated to provide better gripping. The wrench element has a hollow opening  52  in the jaw portion  8  which the gripping jaw  50  is nested, and the gripping surface  51  protrudes from the opening. The gripping jaw is pivotably held in the opening by a pin  58  through corresponding holes  54 ,  56  in the gripping jaw and the wrench element. The gripping jaw  50  is able to pivot since the gripping jaw hole  54  is larger in diameter than the pin  58  going through it. This pivoting action allows the gripping jaw  50  to tighten on the flats of bolt heads. 
     The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.