Abstract:
A one-piece unitary compression cap for securing a pipe or tube on a fitting. The cap includes at least one inward deformation that provides an interference fit between the cap and the pipe or tube. Consequently, the cap cannot fall off the pipe or tube before being permanently crimped.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention is related to compression caps, and more particularly to compression caps used in plumbing connections.  
         [0002]     Compression caps are well known for connecting a section of pipe or tubing to a fitting. The current method is a metal band that is positioned and crimped onto the end of a pipe or tube to secure the tube to a fitting. The cap is crimped using a specially designed tool. These caps may be used in a wide variety of plumbing applications including recreational vehicles, modular homes, marine crafts and beverage dispensing machines.  
         [0003]     The proper positioning of the compression caps on the pipe ends is important. Accordingly, the present caps are designed to enhance the likelihood that the cap will be properly positioned. One such cap is sold by Stadler-Viega of Bedford, Mass. under the Pureflow trademark. As illustrated in  FIGS. 1 and 2 , this cap  100  includes a shoulder  110  at one end  120  to provide a positive stop for the pipe  130  within the cap. The cap also defines a “witness window”  115  to permit visual observation and confirmation that the pipe is properly positioned within the cap end against the flange  110 . The flange  110  assists in properly positioning the cap on the tube end.  
         [0004]     Unfortunately, there are difficulties in the installation of conventional compression caps. After a cap is placed on the end of the pipe, it must be physically held in place until the fitting is inserted into the pipe and the cap is compressed, which requires two hands. If this is not done, the cap may fall off the tube. This problem is exacerbated when the installation of a cap is attempted in a tight space, because the user may only be able to reach the pipe and the cap with one hand.  
       SUMMARY OF THE INVENTION  
       [0005]     The aforementioned problems are overcome by the present invention wherein a compression cap is provided with an inward deformation that provides a friction fit or an interference fit between the cap and the outer surface of the pipe.  
         [0006]     In the disclosed embodiment, the inward deformation is a plurality of longitudinal ribs evenly spaced about the circumference of the cap. As the cap is placed on the pipe, the ribs engage the outer surface of the pipe creating friction and thereby preventing the cap from falling off the pipe prematurely.  
         [0007]     The present invention provides a number of advantages over conventional compression caps. First, users of the present invention are no longer required to hold the cap in position on the pipe, or to keep the pipe in an upright position prior to placing the pipe onto the fitting. Second, the inward deformation aids in preventing the cap from slipping, moving, or being pushed out of position before the crimp is performed. Third, the number of caps lost inside walls or compartments where pipes are located will be reduced, because caps will be less likely to fall off the pipe after they are placed there. Fourth, installation of caps in tight spaces is much easier with the present invention, because the same hand can be used to place the cap on the pipe, then insert the fitting, and then crimp the cap. Fifth, the inward deformation contributes to a stronger connection between the pipe and the fitting or other object inside the pipe.  
         [0008]     These and other objects, advantages, and features of the invention will be readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of a prior art cap in combination with a pipe and a fitting.  
         [0010]      FIG. 2  is a perspective view of the prior art cap.  
         [0011]      FIG. 3  is a perspective view of the cap of the present invention in combination with a pipe and a fitting.  
         [0012]      FIG. 4  is a perspective view of the cap.  
         [0013]      FIG. 5  is a sectional view taken along line  3 - 3  in  FIG. 4 .  
         [0014]      FIG. 6  is a sectional view taken along line  6 - 6  in  FIG. 3 .  
         [0015]      FIG. 7  is a perspective exploded view of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     A compression cap in accordance with the preferred embodiment is shown in  FIG. 3  and generally designated  10 . The cap  10  is preferably a metal band that is capable of slidably fitting over a pipe or tube  12 . The cap  10  preferably includes a plurality of spaced apart ribs  14 , a positive stop flange  16 , and a witness window  18 . In operation, the cap  10  is placed over the end of a pipe  12 , and a fitting  22  is inserted into the cap  10  at the same end of the pipe  12 . The cap  10  is then crimped with a crimping tool (not shown) to compress the cap  10  about the pipe  12  and the fitting  22 , securing the fitting  22  inside the pipe  12 .  
         [0017]     I. Structure  
         [0018]     Shown in  FIGS. 6 and 7 , the pipe  12  is well known and generally comprised of, but not limited to, plastic, such as PVC or PEX (cross linked polyethylene). The pipe includes an outer surface  19 , and an end  23  that will receive the cap  10 . Depending on the desired application, the pipe may be a rigid or flexible, and may have a variety of standard sizes. The fitting  22  is also well known and is available in standard sizes. They are generally comprised of a metal, such as brass, or plastic, and include at least one insert  21  having a diameter slightly smaller than the inner diameter of the pipe  12  such that it can be inserted into the end  23  of the pipe  12 . The T-shaped fitting  22  shown is intended to be exemplary of just one type of such pipe fittings.  
         [0019]     As shown in  FIG. 4 , the cap  10  is generally a metal band having a circumference of any desired size so that it fits over a desired pipe or tube. The metal band  10  includes a first end  24 , a second end  26 , and a side wall  28  extending between the first end  24  and second end  26 . The width of the side wall between the first and second ends  24  and  26  may vary with the desired application. The side wall  28  also includes an inner surface  32 , an outer surface  34 . In the preferred embodiment, a lip  38  extends radially outward from the second end  26 . The lip  38  includes a radius  40  that forms a smooth transition with the side wall  28 .  
         [0020]     The side wall  28  also includes a plurality of inward deformations. As shown in  FIGS. 4 and 5 , in the preferred embodiment, the inward deformations are a plurality of ribs  14 . The ribs  14  preferably extend across the substantial width of the side wall  28 , forming an indentation  42  in the outer surface  34  and a corresponding protrusion  44  on the inner surface  32 . The depth of the protrusion  44  may vary depending on the desired interference between the ribs  14  and the pipe  12 . In a preferred embodiment, three ribs  14  are spaced evenly about the sidewall  28 . However, any number of ribs  14  may be used, and the ribs  14  may have a different orientation, such as running circumferentially about the cap  10 . Alternatively, the inward deformations may be a number of dimples, or a differently shaped inward deformation that creates a friction fit between the cap  10  and the pipe  12 .  
         [0021]     In the preferred embodiment, a positive stop flange  16  extends radially inward from the first end  24  of the cap  10 . The flange  16  preferably extends around the entire circumference of the cap  10 , having an inner surface  50 , and an outer surface  52 . The depth of the flange  16  is approximately the same, but not greater than, the thickness of the pipe  12 , so that the fitting  22  may still be inserted through the cap  10  and into the end of the pipe  12 . In another embodiment, the side wall  28  includes a hole  48 , or witness window. The hole  48  is proximate to the first end  24  of the cap  10 , allowing a user to view the pipe  12  through the window  48  when the cap  10  is placed on the pipe  12 .  
         [0022]     II. Operation  
         [0023]     In operation, the second end  26  of the cap  10  is positioned proximate to the end  23  of the pipe  12 . A user will then slide the cap  10  onto the end  23  of the pipe  12 . As the cap  10  slides onto the pipe  12 , the lip  38  on the second end  26  of the cap  10  serves to guide the pipe  12  into the cap  10 , and then the ribs  14  engage the outer surface  19  of the pipe  12 , creating a friction fit between the ribs  14  and the pipe  12  for crimping. The pipe  12  is slid onto the cap  10  until the end  23  of the pipe  12  contacts the inner surface  50  of the flange  16 , and the pipe  12  is visible through the window  48 . The flange  16  prevents the cap  10  from sliding farther onto the pipe  12 , and the friction fit created by the ribs  14  prevents the cap from sliding off the pipe  12  without a force being applied by the user. Once the cap  10  is in place, the insert  21  of the fitting  22  is inserted into the end  23  of the pipe  12 , and the cap  10  is crimped with a crimping tool to compress the cap  10  onto the pipe  12 , and compress the pipe  12  onto the fitting  22 .  
         [0024]     The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.