Abstract:
A ring cutting tool for cutting a ring which encircles tubing, the ring cutting tool having a first member with a jaw at one end and a handle at the other end, a second member having a jaw at one end thereof, and a handle at the other end thereof, the first and second jaws being in a substantially abutting relationship when in a closed position, the jaws providing jaw cutting surfaces which define an angle of between 20° and 35°. The ring cutting tool permits an easy lateral cutting and breaking apart of a compression ring.

Description:
[0001]    The present application claims priority on U.S. Provisional Application Serial No. 60/189,618 filed Mar. 15, 2000. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to improvements in a cutting tool of the plier type which is commonly used to cut various materials of differing shape and hardness.  
         BACKGROUND OF THE INVENTION  
         [0003]    Cutting tools of the plier type similar to the present invention are now in widespread use. Cutting pliers utilizing diagonal and straight jaws are used to cut multiple shapes of various materials. However, when they need to cut a geometric shape such as a ring encircling tubing, the cut needs to be done with the extreme edge of the jaws.  
           [0004]    This explains why plumbers and other persons have been using hacksaws for over twenty years to cut off compression rings of medium strength materials such as copper or aluminum. Indeed, many plumbers will cut the flexible pipe and throw away the fittings to avoid the difficulties of cutting a ring with currently available tools.  
           [0005]    Other proposed systems to cut these rings have included the use of a roto-tool with a cutting wheel. A tool bit closing tool has also been developed for cutting such rings. These two systems to cut the rings from a water pipe or conduit are more complicated, more costly, and do not provide the capability to extract the ring after it is cut. Also, the devices do not necessarily provide multiple size cutting capability.  
         SUMMARY OF THE INVENTION  
         [0006]    It is an object of the present invention is to provide a simple, reliable, and versatile hand tool which permits plumbers and other users to cut a copper or similar ring surrounding a conduit when such action is needed. Examples of the use of such rings include their use on current water lines, cutting off plugs after pressure testing, or dismantling a fitting.  
           [0007]    A second object of the present invention is to provide a ring cutting tool in which the jaws and cutting edge geometry permit an easy lateral cutting and breaking apart of a compression ring in a first motion, and its pulling away from the pipe in a second motion.  
           [0008]    A third object of the present invention is to permit the operator of the tool to pull off the cut ring through a second operation simply by using the ring cutting tool to “bite” the ring near the cut area and pull on the tool to unroll and free up the ring.  
           [0009]    A fourth object of the present invention is to provide a ring cutting tool which can be used with any size of ring since the cut is done laterally from edge to edge. A still further object of this invention is to combine the previous noted advantages of the ring cutting tool which incorporates other functions such as a hammer, wire cutters, pliers, etc.  
           [0010]    A still further object of the present invention is to provide a ring cutting tool which can be manufactured in a similar manner as current plier tools.  
           [0011]    According to one aspect of the present invention, there is provided a ring cutting tool suitable for cutting a ring from tubing, the ring cutting tool comprising a first member having a first member jaw at one end thereof and a first member handle at an opposed end thereof, a second member having a second member jaw at one end thereof and a second member handle at an opposed end thereof, the first jaw having a first jaw cutting surface formed thereon, the second jaw having a second jaw cutting surface formed thereon, the first and second members being pivotably connected together such that the first jaw cutting surface and the second jaw cutting surface can move from a first spaced apart position to a second position wherein the jaw cutting surfaces are in a substantially abutting relationship and the first jaw cutting surface and the second jaw cutting surface defining an angle of between 20° and 35° when in the second position.  
           [0012]    The cutting tool of the present invention may have the same general characteristics of current cutter pliers providing a mechanical advantage of 5 to 7, where 40 to 50 lbs. of handle pressure provide 200 to 350 lbs. of force at the tip of the jaws, which is sufficient to cut through any copper ring used currently in flexible water line. Those copper rings with a thickness of 0.050 inch to 0.060 inch and a width of  {fraction (5/16)} inch to  ⅜ inch may easily be cut by the tool of the present invention with a single closure of the jaw across the ring.  
           [0013]    As aforementioned, the ring cutting tool of the present invention is suitable for cutting rings surrounding a conduit. In order to achieve the above, the blades have a geometry which permits the blades to bite into the ring and not slip therefrom.  
           [0014]    It is preferred that the jaw cutting surfaces, in the preferred embodiment, and when in a closed relationship, define an angle of between 20° and 35° . Even more preferably, the angle is between 25° and 30°. It is also preferred that the edges of the jaw adjacent the conduit slope backward therefrom to provide sufficient clearance. The angle of slope is preferably between 5° and 25° and even more preferably, between 8° and 15°.  
           [0015]    The ring cutting tool of the present invention may incorporate many conventional abilities therein. Thus, the two jaws may have the capability of functioning as a hammer and/or claw. Even further, there may be provided the capability, as will be discussed in the preferred embodiments, of the tool functioning as a wire cutter, a conventional plier, etc. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which:  
         [0017]    [0017]FIG. 1 a  is a side view of a ring cutting tool in accordance with a first embodiment of the invention, the tool being shown ready to cut a ring;  
         [0018]    [0018]FIG. 1 b  is a side view of the ring cutting tool of FIG. 1 a  after cutting through the ring;  
         [0019]    [0019]FIG. 1 c  is a top view of the ring after it has been cut;  
         [0020]    [0020]FIG. 2 a  is a side view of a ring cutting tool prior to cutting a ring in accordance with a second embodiment of the present invention;  
         [0021]    [0021]FIG. 2 b  is a side view of the ring cutting tool of FIG. 2 a  after cutting through the ring;  
         [0022]    [0022]FIG. 3 a  is a side view of a ring cutting tool in accordance with a third embodiment of the invention;  
         [0023]    [0023]FIG. 3 b  is a front view of the ring cutting tool of FIG. 3 a ;  
         [0024]    [0024]FIG. 3 c  is a view along line  2 - 2  of FIG. 3 a ; and  
         [0025]    [0025]FIG. 3 d  is a view along line  3 - 3  of FIG. 3 b.   
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    A first embodiment of the ring cutting tool of the present invention is shown in FIG. 1 a  to  1   c  and will now be referred to in greater detail. FIG. 1 a  is a side view of a portion of tool  8  is positioned to start cutting a ring  30 . FIG. 1 b  shows the ring cutting tool in its fully closed position at the end of the cutting operation. FIG. 1 c  shows the cut copper ring after the ring cutting tool is reopened and pulled away from the ring.  
         [0027]    The ring cutting tool  8  shown in FIG. 1 a has a configuration that is customary in most medium and heavy duty plier-type tools. A first member is comprised of a handle  10  and a hammer jaw  14  and a second member is comprised of a handle  12  and a puller jaw  16 ; the two members are operatively connected through a fastener  18 . Fastener  18  is a heavy rivet pin or alternatively could be a hardened bolt and locknut. Cutting edges  20  and  22  are provided on jaws  14  and  16  respectively. As will be discussed hereinbelow, the geometry and hardness of these cutting edges are important in providing the cutting capability of tool  8 . Front stoppers  24  and rear stoppers  26  are provided to limit the rotational closure of the jaws  14  and  16  and therefore prevent the cutting edges  20  and  22  from contacting each other.  
         [0028]    The fabrication of the ring cutting tool  8  may be similar to that of many plier-type tools. First, an alloy or carbon steel is cast or forged. Then machining is performed while the steel is in a soft temper (well annealed). The tool is then hardened and tempered in order to achieve Rockwell C hardness of around  54 - 58 . This is followed by an application of black oxide or other rust prevention treatment. The final steps in the fabrication of the ring cutting tool are grinding and sharpening the cutting edges, polishing, coating the handles for comfort (plasticoat), and assembling (using rivets or a bolt and nut assembly). The front clearance, edge angle, backward slope of the cutting angle and tool hardness are features of the present invention that will be discussed hereinbelow and that facilitate easy repetitive cutting of any size copper ring or other similar connection used on a flexible pipe. All fabrication methods and techniques used in the construction of the ring cutting tool are current technologies.  
         [0029]    A second embodiment of the present invention is shown in FIG. 2 a  which is a side view of the ring cuffing tool at the start of the ring cutting operation. FIG. 2 b  shows a side view of the second embodiment of the tool at the end of the cutting stroke. This embodiment is a lighter and simpler ring cutting tool than the first embodiment. There is no hammer or puller jaw in this configuration.  
         [0030]    The ring cutting tool of FIG. 2 a  has two handles  42  and  44  directly connected to cutting edges and jaws  50  and  48  respectively. Arm  42  and jaw  50  are operatively connected to arm  44  and jaw  48  by a fastener  58 . Stopper surfaces  46  are shown apart since the ring cutting tool is open at the start of the ring cutting operation.  
         [0031]    Pipe fitting  56  is fitted inside a flexible pipe  52  and is shown being sealed around fitting  56  by a copper ring  54  which has been previously crimped. The ring cutting tool is shown pressing against the flexible pipe  52  in order to achieve a clean cut.  
         [0032]    This second embodiment of the ring cutting tool is shown as a side view in FIG. 2 b  when the tool has cut through the copper ring  54 . Handles  40  and  42  are now in closed position, as are the jaw and cutting edges  48  and  50 . Stopper surfaces  46  are now abutting each other.  
         [0033]    Fabrication of the tool shown in FIG. 2 a  is similar to the main embodiment shown in FIG. 1 a.    
         [0034]    A third embodiment of the ring cutting tool incorporates three extra features: a wire cutting capability, a rear plier capacity, and a ring punching cavity. This embodiment is shown in FIG. 3 a  which is a side view of the ring cutting tool. A front view of the jaws along line  1 - 1  is shown in FIG. 3 b . A cross section of the rear plier jaws is shown in FIG. 3 c  along the line  2 - 2 . FIG. 3 d  shows a view of the cutting edge along line  3 - 3  of FIG. 3 b.    
         [0035]    The ring cutting tool of FIG. 3 a  following a third embodiment has two handles  62  and  64  directly connected to jaws  78  and  80 . These two parts of the ring cutting tool are operatively connected and are held together with precision by a bolt and locknut fastener  72 . Handle  64  is directly linked to hammer jaw  80  and directly in line with cavity  90  and hammering handle end  96 . A cutting edge  70  provides a wire cutting capability. Notches  98  allow the tool to cut heavy wire. This embodiment has rear plier capability through jaws  66  and  68 . One other feature of the third embodiment is the ring cavity  90  with punching edges  94  which allows the plumber to deform the flexible tubing before attempting to cut the copper ring when needed.  
         [0036]    Stopper surfaces  74  prevent the front jaws from completely closing and damaging the cutting apex  92  of cutting edges  76  and  82 . Cutting edges  76  and  82  require a cutting angle  84  of around 20° to 35°. It is to be noted that the cutting jaws have a front clearance shown by number  88  which preferably is between 5 and 20° and even more preferably between 8° and 15°.  
         [0037]    As seen in FIG. 3 a , there is an upper claw jaw  78  and a lower hammer jaw  80  having cutting edges  76  and  82  respectively. The front view of the tool shows the narrow edges  94  and the cavity  90 . The width of the cutter edge  98  is preferably between 0.01 and 0.10 inches. The angle of the cutting edges  76  and  82  as above mentioned is indicated by the extended lines  86  and is preferably between 20° to 35° and more preferably between 25° to 30°.  
         [0038]    [0038]FIG. 3 c  shows a cross section of the double jaws  66  and  68  along line  2 - 2  of FIG. 3 a . Details of the cutting edge  76  of jaw  78  are shown in FIG. 3 d , taken along line  3 - 3  of FIG. 3 b . Shown in this figure are the rotating section of handle  64 , the stopper surface  74 , the cutting edge  76 , and apex of the cutting edge  92 .  
         [0039]    The fabrication of the third embodiment of the invention is similar to the first and second embodiments.  
         [0040]    The ring  30  to be cut and removed is shown in FIG. 1 a . The flexible pipe  28  is engaged around the fitting  32 , and the copper ring  30  has been previously crimped to seal the flexible pipe  28  to the fitting  32 . To begin the ring cutting operation, the tool  8  is held in an open position. FIG. 1 a  shows a side view of the tool positioned to start the ring cutting operation. The cutting edges of the tool are pressed against the flexible tubing with the copper ring between the apex of the cutting surfaces. The tool handles  10  and  12  are pressed together with approximately 50 to 60 lbs. of pressure. As the handles are closed, the tool can be twisted to open the ring up to around ¼″. FIG. 1 b  shows the ring cutting tool  8  in a fully closed position at the end of the cutting operation. FIG. 1 c  shows the cut copper ring after the ring cutting tool is reopened and pulled away from the ring. Surfaces  36  show the cuts done by cutting edges  20  and  22 . There is a deformation angle of between about 20° to 40° which is approximately the same as the angle of the cutting edges. A center surface  38  is very small, around 10% of the original width of the ring. This surface is not cut, but broken away from the other side by the closure of the tool.  
         [0041]    The cutting edge of the tool can be used to cut the copper ring in a second place, causing the ring to fall off in two pieces. Or, instead of cutting the ring twice, after the first cut, the front cutting jaw can be used as an ordinary plier to bite into one side of the ring and simply pull it farther open and remove it. An ordinary screwdriver can also be used to pull the ring off after the first cut.  
         [0042]    While several embodiments of the invention have been shown and described, it is to be clearly understood that the invention is not to be limited to the exact construction illustrated and described. But instead, that many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.