Adjustable box wrench

An improved adjustable box wrench having a mouth (9) with a plurality of gripping surfaces (27, 31, 32) for surrounding a nut, bolt or the like. A movable jaw (5) allows the size of the mouth to be altered when a worm screws (8) is turned. The worm screw (8) has gear (24) which fit between teeth (20) in an arm (4) extending from the movable jaw (5). The adjustment arm (4) and worm screw (8) fit into cavities (14, 17) in the wrench body (1). Increased lateral support for the movable jaw is provided by at least one protrusion (19) on a side (21) of the jaw which fits into and moves longitudinally within at least one channel or groove (26) in fixed gripping surfaces (32) on opposite sides of the mouth (9). At least one removal slot (33) is provided to enable assembly and disassembly of the at least one protrusion (19) into the at least one channel or groove (26). A removable closure plate (6) covers the adjustment arm (4) and the worm screw (8) and facilitates assembly of the wrench and disassembly for repair or other purposes.

FIELD OF THE INVENTION
 The present invention relates to tools and, more particularly, to an
 improved wrench which is adjustable to fit completely around any size of
 nut, bolt or the like.
 BACKGROUND OF THE INVENTION
 Conventional adjustable wrenches utilize a pair of jaws which contact only
 two sides of a nut or a bolt, thereby making the wrench prone to slipping
 during use. Such wrenches also allow too much play due to the adjustment
 mechanisms used therein. Slippage during use can cause injury to the
 user's knuckles or other part of the hands. In an effort to overcome such
 problems, adjustable wrenches which grip nuts and bolts on all sides, also
 known as "box wrenches," have been developed. However, current box
 wrenches often still allow too much play, thereby losing their grip or
 lock on a nut or bolt during use.
 Thus, there exists a need for an improved adjustable box wrench that
 eliminates play and provides a non-slip grip or lock on bolts and nuts
 which are not provided by current box wrenches.
 The most pertinent prior art includes the following patents:

Patent No.
 (U.S. unless
 stated otherwise) Inventor Issue Date
 390,422 White Oct. 02, 1888
 4,766,786 Jeremic Aug. 30, 1988
 Des. 239,759 Glantz May 04, 1976
 4,987,805 Ejdenwik Jan. 29, 1991
 Swed. 60657 Mar. 11, 1923
 Des. 313,925 Cone Jan. 22, 1991
 Des. 322,545 Cone Dec. 24, 1991
 3,204,497 Dinkler Sep. 07, 1965
 717,390 Gray Dec. 30, 1902
 Des. 303,916 Colvin Oct. 10, 1989
 Des. 304,669 Boyd et al. Nov. 21, 1989
 4,967,613 Cone Nov. 06, 1990
 The White patent teaches an adjustable box wrench with a gripping jaw which
 uses a thumb nut on a screw rod as the adjustment mechanism. The Jeremic
 patent discloses an adjustable wrench with a removable key adjustment
 mechanism. The Glantz patent shows an adjustable ring spanner for a
 wrench. The Ejdenwik patent discloses an adjustable wrench with a box end
 different from the present invention. The Swedish patent shows a wrench
 with an adjustable box end. The two Cone design patents show adjustable
 box wrenches with gripping ends. The Dinkler patent teaches a double ended
 adjustable box wrench. The Gray patent discloses a double-ended adjustable
 wrench. The Colvin patent shows another double ended adjustable box wrench
 with a different gripping head than the present invention. The Cone
 utility patent teaches an adjustable box wrench that requires a large
 aperture in the jaw slot into which the thumb wheel screw and the threaded
 adjustment rod must fit. Thus, as designed the adjustment mechanism of the
 Cone patent allows considerable play in the adjustment mechanism, making
 it susceptible to slippage during use.
 Although the prior art contains many patented box wrenches, none has the
 same structure as the present invention which provides the benefits of the
 present invention as is described and illustrated herein.
 SUMMARY OF THE INVENTION
 The present invention provides an improved adjustable box wrench which:
 Provides a better grip on nuts, bolts and the like by eliminating play in
 the grip;
 Is more precise;
 Provides a more lateral support, thereby even further reducing slippage;
 Is stronger than conventional box wrenches;
 Is safer than other adjustable box wrenches because it reduces slippage and
 thereby reduces the likelihood of injury; and
 Provides a "lock" on a nut or bolt, thereby reducing the likelihood of
 slippage.
 The present invention includes an improved adjustable box wrench having a
 handle and jaw portion. The jaw portion has a plurality of gripping
 surfaces which form a closed mouth for placing around bolts, nuts and the
 like. Two of the gripping surfaces are longitudinally located on opposite
 sides of the mouth and are fixed. A third gripping surface is fixed and is
 located at the distal end of the mouth and a fourth gripping surface
 resides on a movable jaw which is adjustable according to the size of the
 nut, bolt or the like on which the wrench is used. An adjustment arm is
 connected to the movable jaw on an opposite side of its gripping surface.
 The adjustment arm moves longitudinally within a cavity located in the
 wrench between the mouth and the handle. Means for moving the adjustment
 arm is also provided in the cavity adjacent to the arm in the wrench. An
 elongated handle is provided which extends longitudinally from the jaw
 portion to provide sufficient leverage for turning nuts, bolts and the
 like. To facilitate assembly and disassembly of the wrench for repair or
 other purposes, a removable closure plate is provided which covers the
 adjustment arm and adjustment means. The fixed gripping surface on the
 distal end and the movable gripping surface on the movable jaw at the
 proximal end of the mouth, may each have two equal length angular surfaces
 indented outward from the center of the mouth to provide more lateral
 support to the gripping surfaces for use on nuts and bolts having more
 than four sides. For increased strength and to reduce slippage the mouth
 may contain grooves in the two longitudinal gripping surfaces and the
 movable jaw may have outward protrusions on its sides which fit into and
 move within the grooves whenever the size of the mouth is adjusted. The
 adjustment means use to move the adjustment arm, thereby changing the size
 of the mouth, is preferably a worm screw with helical gears on its
 circumference which fit into teeth on the adjustment arm, such that when a
 worm screw is turned it causes the adjustment arm to move longitudinally
 within the longitudinal cavity, thereby moving the movable jaw and
 altering the size of the mouth as desired.
 In addition, the present invention is directed to an adjustable box wrench
 comprising a generally elongated handle, a head connected to one end of
 the elongated handle with an aperture provided in the head. A movable jaw
 is positioned in the aperture and includes a first gripping surface and
 sides. The movable jaw slides between the proximal end and the distal end
 of the aperture for allowing the wrench to selectively grip a workpiece.
 At least one protrusion is provided on one of the sides of the movable
 jaw. Further, an adjustment arm is connected to the movable jaw on an
 opposite side of the first gripping surface. A gear is also provided for
 cooperating engagement with the adjustment arm for selectively moving the
 movable jaw. A second gripping surface is provided at a distal end of the
 aperture in opposing relationship to the first gripping surface. Third and
 fourth gripping surfaces extend between the first and second gripping
 surfaces, the third gripping surface being in opposing, spaced apart
 relation to the fourth gripping surface.
 Still further, at least one support groove is provided in one of the third
 and the fourth gripping surfaces for mating engagement with the at least
 one protrusion to increase lateral support of the movable jaw. And, at
 least one removal slot is located along the support groove for permitting
 removal of the at least one protrusion from the support groove to
 disassemble and repair the wrench. Moreover, the at least one protrusion
 can be only one protrusion, a pair of protrusions with one protrusion on
 each side of the movable jaw, or any suitable number of protrusions. In
 addition, the at least one support groove can be only one support groove,
 a pair of opposing support grooves or any suitable number of support
 grooves. Likewise, the at least one removal slot can be only one removal
 slot, a pair of removal slots or any suitable number of removal slots.
 Also, the at least one protrusion can be located adjacent a lowermost end
 of the one of the sides to provide smooth sliding operation. Moreover, the
 movable jaw and the one or more protrusions can be unitary as in
 one-piece.
 The head of the wrench includes a top surface and a bottom surface that
 taper inwardly toward each other beginning at the removable closure plate
 and permits insertion of the wrench into confined spaces and reduces
 material and weight.
 The above features and advantages of the present invention should become
 even more readily apparent to those skilled in the art upon a reading of
 the following detailed description in conjunction with the drawings
 wherein there is shown and described illustrative embodiments of the
 invention.

Referring to FIG. 1, the wrench body 1 contains an elongated handle 2 which
 extends longitudinally from the head of the wrench 3. The head of the
 wrench 3 contains a mouth or cavity 9 which is designed to fit around a
 nut, bolt or the like. The mouth 9 is adjustable in size by moving a
 movable jaw 5 between two longitudinal gripping surfaces 32 on opposite
 sides of the mouth 9. The slanted gripping surface 31 of the movable jaw,
 together with the two longitudinal gripping surfaces 32 and the fixed
 griping surface 27 on the distal end of the mouth completed or enclosed
 the head of a nut or bolt or the like on which the wrench is being used.
 As further illustrated in FIGS. 1, 2, 3 and 4, the movable jaw 5 is moved
 longitudinally by means of an adjustment arm 4 that is contained in a
 cavity 14 between the handle 2 and the head 3 of the wrench. The cavity 14
 is large enough to accommodate the full movement of the arm 4 so that the
 movable jaw 5 can move within the entire length of the mouth 9 to fit a
 wide range of sizes of nuts, bolts and the like.
 As shown in FIGS. 5, 6 and 7 the adjustment arm 4 contains angular teeth
 20. The adjustment means consists of a worm screw 8 as shown in FIG. 8,
 which is mounted by a holding pin FIG. 18 in a cavity 17 adjacent and
 contiguous with the cavity 14 for the adjustment arm 4. The worm screw 8
 contains angular turning gear 24 which fit between the teeth 20 and the
 adjustment arm 4 such that when the worm screw 8 is turned by a user's
 fingers the adjustment arm 4 in turn moves the movable jaw 5, thereby
 changing the size of the mouth 9. The combination of the worm screw 8 and
 adjustment arm 4 provides an adjustment means that is precise, accurate
 and reduces play in the movable jaw 5 when the mouth 9 is around a nut,
 bolt or the like.
 To provide further lateral support for the movable jaw 5, as shown in FIG.
 9, a longitudinal channel 26 is provided in the longitudinal surfaces 32
 on the opposite sides of the mouth 9 into which a protrusion 19 on each
 side of the jaws 21 is inserted and moves within as the size of the mouth
 9 is adjusted. The proximal gripping surfaces of the movable jaw 5 and the
 opposing distal gripping surface 27 would be comprised of equal length
 angular surfaces 31 on the movable jaw 5 and on the distal gripping
 surface 27. These gripping surfaces would be slanted outward from the
 center of the mouth to meet at vortices 22 on the movable jaw 5 and 25 on
 the distal fixed gripping surface, respectively. In this manner the mouth
 9 of the wrench could be used on a variety of nuts and bolts ranging from
 those having four sides or more.
 As shown in FIGS. 1, 2 and 3, to facilitate assembly of the wrench and
 disassembly for repair or other purposes, the wrench may have a removable
 closure plate 6 covering the cavity with adjustment arm 14 and cavity for
 the adjustment worm screw 8 to secure the adjustment arm 4 and worm screw
 8 in place. Preferably the closure plate 6 would have removable securing
 screws 7 which would fit into holes 15 in the wrench body 1. The wrench
 body under the removable closure plate 6 would also have slots 33 at the
 proximal end of the mouth so that the movable jaw 5 and adjustment arm 4
 could be removed by allowing the protrusions 19 on the sides of the jaw 21
 to be lifted. The movable jaw 5 could also contain sides 21 with pointed
 ends 23 which fully contact the longitudinal gripping surfaces 32 to
 provide further lateral support and strength for the wrench.
 In FIG. 10 all of the components of the wrench and the manner of assembly
 are illustrated. First, with the wrench body 1 having a head 3 and handle
 2 as previously described, the holding pin 18 is inserted into the central
 hole 34 in the worm screw 8 which in turn is placed into the cavity 17 in
 the wrench body with the front of the pin 18 being placed into a worm
 screw pin front tip holding cavity 30. Then the adjustment arm 4 and
 removable jaw 5 are placed into the adjustment arm cavity 14 and mouth 9
 so that the gear 24 on the worm screw 8 fit between the slanted teeth 20
 on the adjustment arm 4 and the protrusion 19 on the sides 21 of the
 movable jaw 5 fit into slots 33. The final step in the assembly process is
 to install the closure plate 6 by inserting screws 7 through holes 28 and
 into threaded holes 15 in the body of the wrench 1. In addition, head 3
 includes a top surface 10 and a bottom surface 11 that taper inwardly
 toward each other beginning at the removable closure plate 6. See also
 FIG. 2.
 FIGS. 11 and 12 show a wrench 40 according to a second embodiment of the
 present invention. The wrench 40 has many of the same features as in the
 first embodiment and like numerals have been used to label similar
 structures. In the second embodiment, the wrench 40 has a single
 protrusion 19 on one side 21 of the moveable jaw 5. Preferably, the
 protrusion 19 is located on side 21 that is opposite to the teeth 20 on
 the adjustment arm 4, as illustrated. Alternatively, it is contemplated to
 have only one protrusion 19 on the side 21'. In addition, a single support
 groove 26 shown in FIG. 9 is provided in one of the longitudinal gripping
 surfaces 32 for mating engagement with the protrusion 19 and thereby
 provide increased lateral support of movable jaw 5. Further, one removal
 slot 33 is located along the support groove 26 and permits removal of
 protrusion 19 from the support groove 26 in order to disassemble and
 repair wrench 40. Although protrusion 19 can be located at any position
 along sides 21, 21', protrusion 19 is preferably located adjacent a
 lowermost end of one of sides 21, 21'. As in the first embodiment, movable
 jaw 5 and protrusion 19 can be formed integrally as one piece as a single
 unitary member. Similarly, movable jaw 5 can be formed integrally with
 adjustment arm 4 to make a single unitary member.
 It should become readily apparent that as described and illustrated above
 in relation to the preferred embodiments, this invention provides a new
 and improved adjustable box wrench with improved adjustment means that
 reduces play in the adjustable jaw 5 and which reduces slippage of the
 mouth 9 while used around a nut or bolt. Increased lateral support is
 provided by one or more protrusions 19 which fit into one or more groves
 26 in the opposing longitudinal gripping surfaces 32. Easy assembly and
 disassembly is provided by use of a closure plate 6.
 Although only a few embodiments of the present invention have been
 described in detail hereinabove, all improvements and modifications to
 this invention within the scope or equivalents of the claims are covered
 by this invention.