Abstract:
The wrench stop for preventing a gripping end of a wrench from sliding off the lands of a fastener, such as a nut or bolt head. The wrench stop includes a hole through its center so that the wrench stop slides over the shank of a stud or bolt when fastening a nut thereto. The wrench stop may be magnetized to provide positive attachment to the fastener. The wrench stop may be attached to an open-end wrench, a box-end wrench, a combination wrench, a ratcheting box-end wrench, etc.

Description:
BACKGROUND OF THE INVENTION  
   1. Field of the Invention  
   The present invention relates to wrenches, and more particularly, to a wrench stop for multipoint box-end and open-end wrenches. The wrench stop is a thin circular plate attached to the end of the wrench to prevent the wrench head from slipping off the fastener and to facilitate locating, aligning and positioning the box-end or open-end of the wrench on the bolt head or nut of a fastener being tightened or loosened.  
   2. Description of the Related Art  
   Wrenches in general are well known in the art for tightening or loosening fasteners which are often located in odd and difficult to see locations. One problem with existing wrenches is that the positioning and retention of the box-end or open-end wrench upon a fastener can be relatively difficult, particularly when the wrench is used to position the box-end or open-end on a nut of the fastener in restricted locations where the fastener is not easily viewed when the user is attempting to tighten or loosen the nut.  
   A further problem is that when the bolt head is loosened from the workpiece or the nut is advanced along the threaded bolt shank, the head of the wrench can slip off of the bolt head or  nut, sometimes causing the user to skin or bruise the knuckles on the workpiece. In any event, when this occurs, the user must reposition the box-end or open-end of the wrench on the fastener.  
   In an effort to overcome these deficiencies, there have been numerous attempts to provide a wrench structure that prevents the wrench head from slipping off or past the fastener with subsequent risk of personal injury to knuckles and hands and/or damage to both the wrench and fastener, as well as the consumption of the necessary time in re-positioning the wrench on the fastener when using the wrench.  
   For example, U.S. Pat. No. 2,697,371, issued Dec. 21, 1954 to Bowman, U.S. Pat. No. 1,635,102, issued Jul. 5, 1927 to Watson, U.S. Pat. No. 4,406,188, issued Sep. 27, 1983 to Mills and U.S. Pat. No. 4,787,273, issued Nov. 29, 1988 to Griffith all describe a sliding member attached to the shank of the wrench which is slid back and forth to engage to the bolt and nut of the fastener. This arrangement is cumbersome, time consuming and not suited for use with wrenches having a non-uniform shank. These devices are not cost effective, and the sliding member may easily be damaged and become unusable after repeated use.  
   U.S. Pat. No. 5,983,758, issued Nov. 16, 1999 to Tanner, describes an integral stopper located in alternating triangular areas along the circumference within the gripping portion of a socket near the shoulder to prevent slippage of the wrench past the fastener.   
   U.S. Pat. No. 3,731,722, issued May 8, 1973 to Carr, describes the use of an adjustable, magnetized ringlet with a radial split inserted within the bore of a wrench gripping member, and/or use of a bendable H-shaped strip for holding the ringlet on the top of the box-end of a wrench.  
   U.S. Pat. No. 2,751,802, issued Jun. 26, 1956 to Reuillard, describes a pivotal metal strip attached to a socket head for frictionally retaining the socket against the nut.  
   U.S. Pat. No. 4,058,032, issued Nov. 15, 1977 to Jacks, describes an open-end wrench provided with a resilient insert means, such as a spring wire clip, inserted into the jaw for frictionally engaging the nut of a fastener.  
   None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a wrench stop solving the aforementioned problems is desired.  
   SUMMARY OF THE INVENTION  
   The wrench stop is an attachment for wrenches which aids in aligning the wrench over a fastener and also maintains the wrench in the engaging position on a bolt or nut, thereby greatly facilitating and expediting the tightening or removal of the nut. The wrench stop is a rigid disk or circular plate adapted for attachment to the end of the wrench. The plate has a hole defined through the center of the disk dimensioned so that the shank of a bolt can pass through the hole. The plate is placed on one side of the jaws of an open end wrench, or on one side of  box end or ratchet, so that the wrench end can be fitted over a bolt head or nut, but the plate stops the bolt head or nut from passing completely through the jaws, box end, or ratchet.  
   When used to fasten a nut on a stud or the shank of a bolt, the circular hole keeps the wrench end positioned over the shank. The wrench stop may be magnetized in order to keep the wrench stop positively engaged with the fastener.  
   In another embodiment, the wrench stop may comprise a thin plate having a U-shaped slot defined therein which is attached to an open end wrench. The plate may be fixed to the jaws of the wrench, or the plate may be made of magnetic material for removable attachment to the jaws of the wrench. The plate is attached to the end of the wrench with the U-shaped slot in alignment with the U-shaped jaws, but narrowing the opening defined by the jaws on one side of the wrench, so that the jaws engage the fastener, but the wrench is prevented from sliding downward off the fastener by the plate. The slot is dimensioned so that the shank of a bolt or stud is slidable into the slot, but the nut or head of the bolt is not. The plate may be circular or U-shaped. In a combination wrench, a disk-shaped wrench stop with the circular opening defined therein may be attached to the box end, and a plate having the U-shaped slot defined therein may be attached to the open end.  
   Accordingly, it is a principal object of the invention to facilitate the tightening and removal of the nuts from a fastener located in a restricted area, which is not easily viewed, by providing a wrench stop having a circular plate with a center  hole defined therein over one side of the wrench end so that the plate can slide over the exposed portion of a stud or bolt shank.  
   It is another object of the invention to provide a wrench stop with magnetic property in order to retain the nut or bolt head in the socket grip by positive engagement.  
   It is another object of the invention to prevent a wrench from sliding off a bolt head, nut, or other fastener by providing a wrench stop which prevents the fastener from passing completely through the end of the wrench.  
   Still another object of the invention is to provide a wrench stop for an open end wrench as a thin plate attached to the jaws of the open end wrench, the plate having a U-shaped slot therein permitting the shank of a bolt or stud to slide in the slot, but preventing the jaws of the wrench from sliding downward and off a fastener or bolt head attached to the shank or stud.  
   It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.  
   These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.  

   
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an environmental, perspective view of a wrench stop according to the present invention.   
       FIG. 2  is a side view of a double box-end wrench with a wrench stop according to the present invention attached at each end.  
       FIG. 3  is plan view of a double box-end wrench with a wrench stop attached at each end, one end with a serrated edge plate and the other end with a smooth edge plate.  
       FIG. 4  is a plan view of a combination wrench with a wrench stop according to the present invention attached at each end.  
       FIG. 5  is a side view of the combination wrench of  FIG. 4 .  
       FIG. 6  is a perspective view of a wrench equipped with a wrench stop according to a second embodiment of the present invention.  
       FIG. 7A  is a side view of the second embodiment of a wrench stop according to the present invention for attachment to a box end wrench.  
       FIG. 7B  is a perspective view of the second embodiment of a wrench stop according to the present invention for attachment to an open end wrench.  
       FIG. 8  is a top plan view of a combination wrench having a wrench stop according to the second embodiment of the present invention attached at each end of the wrench.  
       FIG. 9  is a side elevation view of the combination wrench shown in  FIG. 8 .  
   

   Similar reference characters denote corresponding features consistently throughout the attached drawings.  
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS   
   The present invention is a wrench stop, designated as  10  in the drawings, as illustrated in  FIGS. 1-5 . Wrench stop  10  comprises a circular plate  20  having a central hole  22 . The size of the central hole  22  is slightly greater than the size of the bolt shank or stud  18  on which a nut is being tightened or loosened. Wrench stop  10  may be metallic or non-metallic, and is formed of a thin, rigid sheet of material. The central hole  22  snuggly fits over the bolt  18  and assists in aligning, locating and engaging the wrench grip  14  or  26  over the nut  16  of the fastener being loosened or tightened, as illustrated in  FIG. 1 .  
     FIG. 1  is a perspective view of the invention, which shows the general features of the invention. The wrench  12  has a box-end provided with a wrench stop  10  comprising a plate  20  attached on one side of the head. The plate  20  has a central hole  22  with a diameter slightly greater than the diameter of the shank of the bolt  18 . The diameter of the plate  20  is greater than the diameter of the box-end  14 , but less than the outside dimension of the box-end of the wrench. The plate  20  may be attached to the wrench  12  by welding or chemical adhesive.  
     FIG. 2  shows a side view of a double box-end wrench  12  with wrench stops  10 . The plate  20  of the wrench stop  10  is attached on one side of the wrench head, so as not to interfere with the operation of the wrench.   
     FIG. 3  shows a plan view of a double box-end wrench  12  having wrench stops  10  attached at each box-end. Two embodiments of wrench stops  10  are shown. One wrench stop  10  is shown having a plate  20  with serrated edge  28  and the other wrench stop  10  is shown having a plate  20  with smooth edge  30 . The outside diameter of the plate  20  is greater than the inner diameter of the box-end  14  but less than the outside dimension of the box-end  14 . The plate  20  is provided with a central hole  22  having a diameter slightly larger than the diameter of the shank of a bolt sized to receive a nut which the wrench head is designed to fasten. The central hole  22  is aligned so that the hole  22  is co-axial with the centerline of the wrench head.  
     FIG. 4 , shows a plan view of a combination wrench  24  having an open-end  26  at one end with a plate  21  of wrench stop  10  attached thereto and a box-end  14  at the other end with a plate  20  of wrench stop  10  attached thereto. The plate  20  at the box end  14  is as described above, being a circular plate  20  provided with a central hole  22  having a diameter slightly larger than the diameter of the shank of a stud or bolt on which a nut is being loosened or tightened. However, plate  21  attached at the open end  26  of the wrench  24  is U-shaped, having a slot  23  defined therein which is narrower than the U-shaped opening formed by the jaws of the open end  26 . The plate  21  may be circular with the  U-shaped slot defined therein, or may be U-shaped. The slot  23  is wide enough to permit the shank of a bolt or stud to slide to the slot  23 , but is narrower than the open end  26  of the wrench  24 , so that the wrench stop  10  prevents the jaws of the open end  26  from sliding downward on the lands of a nut or bolt head, so that the open end  26  does not slide off the fastener.  
     FIG. 5  shows a side view of the combination wrench  24  of  FIG. 4 . The side view clearly shows that the wrench stops are only attached to one side of the wrench  24 .  
   According to the first embodiment of the present invention, the wrench stop  10  is permanently affixed to the wrench by any conventionally known method, including forging, casting, welding, adhesive bonding by epoxy or other resins, etc. In a ratcheting box-end wrench, the wrench stop  10  may be attached to the wrench head, or to the ratchet gear. The wrench stop  10  may be made from a magnetized ferromagnetic material, such as steel, or from a hard, rigid, plastic material having magnetized particles embedded therein, or the wrench stop  10  may have an inlay of magnetized material interposed between the stop  10  and the wrench head. The plate  20  has a thickness preferably in the range of {fraction (1/16)}″ to ¼″ thick.  
     FIG. 6  shows another embodiment of the present invention designated as  100 . The wrench stop  100  is magnetic, and shown  removably attached to the box end  14  of a wrench  12  in  FIG. 6 . In a box end wrench, the wrench stop  100  comprises a top plate  102  with serrated edges, and a magnet  104  sandwiched between the top plate  102  and a bottom toothed plate  106 : The top plate  102 , the magnet  104  and the bottom plate  106  are joined together centrally and form a one-piece assembly. The outer diameter of the top plate  102  is greater than the outer diameter of the magnet  104 ; the outer diameter of the magnet  104  is slightly greater than the diameter of the box-end  14  at the gripping end of the wrench  12 ; and the outer diameter of the toothed bottom plate  106  is slightly less than the box-end  14  at the gripping end of the wrench  12  for removably locking into the box-end  14  of the gripping end of the wrench  12 . Referring to  FIGS. 6 and 8 , the one-piece assembly  100  is provided with a central hole  120  having a diameter slightly larger than the diameter of the shank of a stud or bolt  18  on which a nut  16  is being loosened or tightened. The bottom toothed plate  106  is about {fraction (1/16)}″ thick and removably attaches to the top portion of the box-end  14  at the gripping end of the wrench  12 . Note, the bottom toothed plate  106  is circular for removably attaching to a box-end of a wrench, or is oval shaped for removably attaching to an open end wrench.   
     FIG. 7A  shows an elevation view of the wrench stop  100 , illustrating the top plate  102 , magnet  104  and bottom plate  106  joined together.  
     FIG. 7B  shows a removable wrench stop for an open end wrench. The removable wrench stop for an open end wrench is a thin magentic plate  121  having a U-shaped slot  123  defined therein. The magnetic plate  121  is removably attached to the jaws of an open end wrench or combination wrench with the slot  123  aligned with the jaws of the wrench. The slot  123  is narrower in width than the opening defined by the jaws of the wrench. The slot  123  is wide enough to slide over the shank of a bolt or stud, but wide enough that it does not slide over the nut or bolt head of a fastener, so that the wrench stop prevents the open end wrench from sliding downward and off the fastener.  
     FIG. 8  shows a plan view of a combination wrench  24  having an open gripping end  26  at one end and a closed gripping end  14  at the other end, with a wrench stop  100  attached to the box end  14  and open end  26 , respectively, by magnetic attraction.  
     FIG. 9  shows a side elevation view of the combination wrench  24  having an open gripping end  26  at one end and a closed gripping end  14  at the other end with the wrench stop  100  attached to the respective ends of the wrench  24 .  
   According to the second embodiment of the present invention, the wrench stop  100  is an integral unit which is removably  attached to either side of the gripping end of a wrench before using the wrench for loosening or tightening a nut, the wrench stop  100  being held in place by magnetism.  
   It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.