Abstract:
A hydrant is provided that employs a pipe interconnected to a faucet assembly. The pipe is constructed of a material that is resistant to detrimental affects of corrosion and pitting. Corrosion and pitting of pipes made of copper, as opposed to the plastic material employed, tends to erode a portion of the outlet pipe circumferentially such that if the pipe is later exposed to expansive effects of ice, the pipe could burst, thereby causing damage to the dwelling.

Description:
FIELD OF THE INVENTION 
       [0001]    Embodiments of the present invention are generally related to wall hydrants located on the outside of buildings that are resistant to damage associated with freezing. 
       BACKGROUND OF THE INVENTION 
       [0002]    “Freezeless” wall hydrants, or faucets characteristically employ a fluid closure valve located in a pipe that is positioned within an exterior wall of a building. The fluid closure valve is opened and closed by an elongated rod connected to a handle that is operably associated thereto. Wall hydrants of this construction are “freezeless” since the closure valve that turns on and shuts off the flow of water through the pipe is located within the exterior wall and thus, maintained at a temperature above freezing. The pipe is angled downwardly from the fluid closure valve to allow gravity to pull any water within the pipe from the hydrant. 
         [0003]    The foregoing structure operates very successfully except, for example, in situations where a hose or the like is attached to the hydrant, whereupon subsequent to shut off, water in the pipe is either restricted or prevented from exiting the hydrant by water trapped in the hose. For example, hoses are often interconnected to a wall hydrant on one end and to a selectively openable nozzle on another end. If the nozzle is not opened subsequent to hydrant shut off to allow water to drain from the hose, any water trapped within the pipe will not be able to escape. Thereafter, when the outside temperature drops below freezing, the trapped water in the hose and in the pipe will freeze and expand, which may cause damage to the hydrant. Furthermore, any hydrant damage may not become apparent until the wall hydrant is subsequently turned on, which could be months from the time the damage occurred. To make matters worse, the rupture point may be located within the exterior wall wherein opening the valve subsequent to damage will allow water to exit the rupture point and damage the dwelling. Understandably, this damage may be hidden for quite some time. Hydrant ruptures often do not occur exclusively due to frozen water in the pipe. Rather, ruptures result from ice imposing severe pressure on captivated non-frozen fluid and/or gas in the pipe. Prior art pipes are susceptible to ruptures partially due to their make-up, which makes them prone to pitting and/or thinning. Pitting is generally descriptive of mechanical erosion or corrosion of the inside surface of the pipe by turbulent flow of the carried liquid. The amount of erosion/corrosion is also dependent on the make up of the pipe. Copper pipes have been used to distribute potable water within buildings for many years. Given the increased cost of copper, however, it would be desirous to use thinner walled pipe, furthering concerns over long term reliability of plumbing systems incorporating copper. Despite the reliability of copper, in some environments pits may form in the pipe. 
         [0004]    Corrosion often damages copper pipes in localized areas, i.e. “impingement damage”, which refers to the combined effect of corrosion and erosion caused by rapid flowing turbulent water. If the general speed of water within a copper pipe or degree of localized turbulence in a plumbing system is relatively high, the protective coating (if any) of the copper pipe will be removed from localized areas of the inner surface of the pipe, thereby permitting further corrosion to take place. The attack of metal is caused by the corrosive action of the water and erosive effect related to the mechanical removal of the corrosion product by the turbulent flow. It is unusual for the general water velocity to be so high that impingement damage occurs throughout the entire plumbing system. More commonly, the fluid velocity is sufficiently low enough for satisfactory protective films to be formed and remain in position for most of the water system. Impingement damage, however, most likely occurs where there is a change in the direction of water flow that causes turbulence. In the arena of hydrants, for example, turbulent flow often occurs at the interconnection of the pipe and hydrant head. The turbulence will influence the flow pattern through the pipe and cause erosive removal of material of the pipe, usually in a circumferential pattern. Thereafter if ice expands within the pipe, such areas may rupture. 
         [0005]    As briefly alluded to above, pitting may be prevented by the formation of a protective layer formed on the inner wall of the copper pipe. More specifically, one of skill in the art will appreciate that some forms of metal surface reactions are beneficial, such as when oxidized material remains joined to the parent material. Water containing particular amounts of aluminum that react with the copper pipe to form a protective covering is one example of how beneficial metal surface reactions occur when copper pipe is employed. Unfortunately, due to the requirements of the Clean Water Act, which reduced the permitted amount of aluminum from drinking water, the formation of a beneficial protective layer on copper piping is absent or less than it was in the past. 
         [0006]    Thus, there is a long felt need in the field of plumbing to provide a hydrant that is resistant to pitting and is thus less susceptible to the damaging affects of ice. The following disclosure describes an improved hydrant that employs a pipe made of a material that is resistant to such pitting and that also addresses the effects of expanding ice. 
       SUMMARY OF THE INVENTION 
       [0007]    It is one aspect of the present invention to provide a hydrant that employs a fluid inlet pipe made at least partially of a material that is resistant to pitting. More specifically, one embodiment of the present invention replaces the copper pipe generally employed by wall hydrants with a pipe made of a plastic material. Another embodiment employs a traditional copper pipe having a segment made of a plastic material. For example, one embodiment of the present invention employs a pipe made of cross linked polyethylene (PEX). One of skill in the art will appreciate that other similar material such as high density polyethylene (HDPE), polyvinyl chloride (PVC), chlorinated PVC (CPVC), or any combination thereof, may also be employed. Any similar materials that are resistant the aforementioned problem of pitting may also be employed. The contemplated pipe interconnects to common hydrant assemblies. Preferably, a coupling may be used to interconnect the hydrant assembly to the pipe wherein a band clamp is used to ensure that the pipe is firmly interconnected to the hydrant assembly. Such use of a band clamps, adhesives, sonic welding and spin welding, as opposed to sweating or otherwise interconnecting copper tubes, has the advantage of reducing the risk of fire and is less time consuming. One advantage of employing embodiments of the present invention is the cost savings associated with not using increasingly costly copper. More specifically, in recent years, the price of copper has increased dramatically. By eliminating some or all of the copper used in construction, building costs can be reduced. In addition, by omitting copper the occurrences of copper theft are necessarily reduced. In one embodiment a hydrant employing the contemplated erosion and corrosion resistant tubing weights about 14% less than similar hydrants of the prior art. 
         [0008]    It is another aspect of embodiments of the present invention to provide a common interface between a plumbing system of a dwelling and an outdoor hydrant. More specifically, as materials other than copper are being used on an increasing basis, it has become desirable to ensure that the interconnection between the plumbing system and the hydrant are consistent with respect to the materials of manufacture. One of skill in the art will appreciate that joining different materials may pose a problem with respect to bonding and varieties of thermal expansion rates, for example. Thus, one embodiment of the present invention employs a plumbing system and hydrant that possess similar material properties to address if not alleviate this issue. 
         [0009]    It is yet another aspect of the present invention to employ a plastic base material in plumbing components that may incur higher than normal pitting. More specifically, although the foregoing has been concerned predominantly with hydrants, one of skill in the art will appreciate that the use of PEX tubing as described herein can be used in any location of the plumbing system where pitting may be an issue. 
         [0010]    It is another aspect of the present invention to provide a sleeve for incorporation within the pipe of a hydrant. More specifically, the sleeves described in detail below may be used in conjunction with hydrant assemblies that employ a copper or plastic pipes, but more aptly with copper pipes. The sleeves contemplated herein would be used when a copper tube becomes fragile or ruptures. In operation, a user would disconnect a nut that secures the handle to the hydrant to gain access to the inner portion of the pipe and remove the control rod associated with the valve. The sleeve may then be inserted into the tube to in effect patch the rupture point. 
         [0011]    In one embodiment, the sleeve has an outer diameter approximately equal to the inner diameter of the pipe such that a flow path between from the water source and the weakened or ruptured area is effectively blocked. Another embodiment of the present invention comprises a coiled cylinder that expands when placed within the pipe to patch the ruptured or weakened area. The expandable cylinder may include a compound that is thermally or chemically actuated to harden thereby forming a rigid, similar to cure-in-place-pipe used in exterior pipe repair. The sleeve, as will be outlined in further detail below, can be provided in any shape or size and may be deployed within the pipe in any number of ways. 
         [0012]    It is another aspect of the present invention to provide a removable portion that is affected by the fluid flowing through the tube. More specifically, a sacrificial sleeve is contemplated that is positioned within the pipe. This sleeve is designed to feel the brunt of the corrosive damage. After a predetermined amount of time, the hydrant would be inspected and the sacrificial sleeve could be replaced if necessary. 
         [0013]    Similarly, a sleeve may be employed within a copper pipe and positioned adjacent to the areas of a pipe that is prone to pitting. This sleeve would thus block the turbulent flow from impinging upon the inner diameter of the pipe. Also, one of skill in the art will appreciate that copper tubes may be coated with a material that is less prone or resistant to pitting similar to the corrosive layer that generally formed on copper tubes of the prior art. This coating could be of a plastic material or other corrosive resistant material well known in the art. 
         [0014]    It is another aspect of the present invention to provide a sleeve or other member that alters the flow of fluid through the pipe. For example, a sleeve having a plurality of baffles or restrictions or other mechanisms to alter fluid flow is envisioned such that the areas of maximum turbulent flow are reduced, eliminated or altered. For example, one of skill in the art will appreciate that the pipe may include a thickened portion of copper material wherein the sleeve directs the flow such that impingements occur adjacent to the thickened areas of material, thereby increasing the lifespan of the hydrant. 
         [0015]    The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detail Description, particularly when taken together with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions. 
           [0017]      FIG. 1  is a perspective view of one embodiment of the present invention; 
           [0018]      FIG. 2  is a side elevation view of the embodiment of the present invention shown in  FIG. 1 ; 
           [0019]      FIG. 3  is a cross sectional view of the embodiment of the present invention shown in  FIG. 1 ; 
           [0020]      FIG. 4  is a cross sectional view of a hydrant employing a sleeve; 
           [0021]      FIG. 5  is a partial perspective view of the sleeve of one embodiment of the present invention; 
           [0022]      FIG. 6  is a cross sectional view of a sleeve of another embodiment of the present invention; 
           [0023]      FIG. 7  is a perspective view of a two-piece sleeve of one embodiment of the present invention; 
           [0024]      FIG. 8  is a front elevation view of the sleeve shown in  FIG. 7 ; 
           [0025]      FIG. 9  is a perspective view of a sleeve possessing a coiled cylinder shape of one embodiment of the present invention; 
           [0026]      FIG. 10  is a front elevation view of the sleeve of  FIG. 9  shown in a deployed configuration; 
           [0027]      FIG. 11  is a front elevation view of the a sleeve of yet another embodiment of the present invention; 
           [0028]      FIG. 12  is a front elevation view of  FIG. 11 , wherein the sleeve has been deployed; and 
           [0029]      FIG. 13  is a front elevation view of a sleeve similar to that shown in  FIGS. 11 and 12  shown in a deployed position. 
       
    
    
       [0030]    To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein: 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 # 
                 Components 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 2 
                 Wall hydrant 
               
               
                 6 
                 Pipe 
               
               
                 10 
                 Hydrant assembly 
               
               
                 14 
                 Vacuum Breaker 
               
               
                 18 
                 Fluid drain conduit 
               
               
                 22 
                 Threads 
               
               
                 26 
                 Control rod 
               
               
                 28 
                 Screw 
               
               
                 30 
                 Handle 
               
               
                 34 
                 Bushing 
               
               
                 38 
                 Packing washer 
               
               
                 42 
                 Flange 
               
               
                 46 
                 Valve body 
               
               
                 50 
                 Valve seat 
               
               
                 54 
                 Valve fitting 
               
               
                 58 
                 Water source 
               
               
                 62 
                 Coupling 
               
               
                 66 
                 Band clamping band 
               
               
                 68 
                 Band clamping 
               
               
                 72 
                 Check valve 
               
               
                 76 
                 Sleeve 
               
               
                 80 
                 Throat 
               
               
                 84 
                 Tongue 
               
               
                 88 
                 Groove 
               
               
                 92 
                 Overlap 
               
               
                 104 
                 Locking member 
               
               
                   
               
             
          
         
       
     
         [0031]    It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. 
       DETAILED DESCRIPTION 
       [0032]    Referring now to  FIGS. 1-3 , a wall hydrant  2  of one embodiment of the present invention is shown wherein a pipe  6  is shown interconnected to a faucet assembly  10 . The hydrant assembly  10  includes a vacuum breaker  14  and a fluid drain conduit  18 . The fluid drain conduit  18  may contain threads  22  for receipt of a hose (not shown). A control rod  26  is positioned within the faucet assembly  10  and is interconnected to a handle  30  preferably by a screw  28 . The handle  30  is also associated with the hydrant assembly  10  via a bushing  34 . The control rod  26  is held in place by a packing washer  38 . The hydrant assembly  10  is interconnected to a flange  42  for interconnection to a dwelling. The control rod  26  communicates with a valve body  46  that is adapted to transition by selective rotation of the handle  30  to contact a valve seat  50  of a valve fitting  54  that is interconnected to the water source  58  of a dwelling. 
         [0033]    The pipe  6  provided in one embodiment of the present invention is made of a material, such as plastic, that resists pitting. Preferably, the pipe  6  is interconnected to the faucet assembly  10  via a coupling  62  via a band clamp  66 . A band clamp  68  may also be used to interconnect the pipe  6  to the valve fitting  54 . One of skill in the art will appreciate that all or portions of the hydrant assembly  10  and/or the valve fitting  54  may also be comprised of a material that resists pitting. When the valve body  46  is transitioned away from the valve fitting  54 , water is transferred through the valve fitting  54  and into an annular space between the control rod  26  and the pipe  6 . A check valve  72  is also interconnected to the valve body  46  to prevent backflow of water from the hydrant assembly  10  into the fluid source  58 . One of skill in the art will appreciate that the pipe  6  may be constructed of a flexible plastic to accommodate installation misalignments. If a flexible pipe is employed, the rod  26  may need to be flexible or be replaced with a linkage to accommodate the flex of the pipe  6 . Some embodiments are able to flex at lest about 5 degrees. 
         [0034]    One of skill in the art will appreciate upon review of the drawings that turbulent flow can occur at the junction of the pipe  6  and the hydrant assembly  10  and the junction of the pipe  6  and the valve fitting  54  that will necessarily cause impingement on the inner surface of the pipe  6 . Due to the nature of the material of the pipe  6 , however, turbulent flow will have little influence with respect to pitting of the material. That is, the plastic material used for constructing the pipe  6  of some of the embodiments described herein is made of a substantially non-corrosive material that will not react with the water flowing through the pipe  6 . Although for a given thickness copper pipe generally possesses a higher yield strength than PEX, for example, the latter is not susceptible to pitting. Thus the failure mode experienced by hydrants of the prior art when exposed to the expansive forces and pressure associated with ice being situated in the outlet pipe is avoided. More specifically, turbulent flow, which is present at the marriage of the pipe  6  and the faucet assembly  10 , does not produce the characteristic circumferential thinning and pitting of the pipe  6 . As mentioned above, when exposed to high pressure, the thinned or pitted area is often the main rupture point. 
         [0035]    One of skill in the art will appreciate upon review of the figures that the pipe  6  may be of any material that is not susceptible to pitting, such as PEX, PVC, CPVC or other similar types of materials. Further, the pipe  6  may be interconnected to the hydrant assembly  10  via any common method such as clamps, bonding, spin welding, sonic welding, braces, bands (shown). Various seals may also be employed between the pipe  6  and the faucet assembly  10  to help insure a water tight structure. Again, the valving mechanism shown may be of any valving mechanisms currently used. 
         [0036]    Referring now to  FIGS. 5 and 6 , a cross section view of a hydrant with a sleeve  76  positioned therein. The sleeve  76  is generally a cylindrical piece of material that snugly fits within the tube  6 . When a leak is apparent or suspected, the bushing  34  and packing washer  38  of the hydrant is removed to expose the inner volume of the pipe  6 . Next, the sleeve is placed within the pipe  6  to block the leak point of the tube. The sleeve  76  may be made of various materials, preferably, copper or plastic. One of skill in the art will appreciate that the pipe  6  may include threads and the sleeve  76  may also include threads that are used to mate the sleeve  76  into or onto the pipe  76 . Alternatively, the sleeve may be adhered to the inner surface of the tube or otherwise locked thereto. In one embodiment, the sleeve  76  is placed in the areas of the pipe  6  where maximum corrosion is to be expected. That is, the sleeve  76  is positioned within the pipe  6  prior to corrosion of the pipe  6  which would be corroded, i.e., sacrificed in lieu of the pipe  6 . Thereafter, the sleeve  76  may be removed, inspected, and replaced if needed. In this embodiment of the present invention the sleeve  76  may include a visual indicator of thickness so that one could quickly ascertain whether sufficient wear has occurred to warrant replacement of the sleeve  76 . For example, the sleeve  76  may be made of a plurality of layers, each which have different colors, such that radial wear can be ascertained. Alternatively, the sleeve may possess about the same length as the pipe. 
         [0037]    Referring now to  FIG. 6 , a cross section of another embodiment of the sleeve  76  is shown that includes a throat  80  that would accelerate the flow, or otherwise alter the flow through the pipe. Sleeves  76  of this nature may also be incorporated into the hydrant assembly prior to use. One of skill in the art will appreciate that the plurality of baffles or other flow restriction or enhancement mechanisms may be added to the sleeve  76  or directly to the inner diameter of the pipe to alter the flow characteristics within the pipe to prevent or alter the corrosion characteristics of the pipe. 
         [0038]    Referring now to  FIGS. 7 and 8 , a two-piece sleeve  76  is shown that is composed of two interlocking halves. The halves may interlock by way of a tongue  84  and groove  88 , but such interconnection is not necessarily required. In operation, one would place one sleeve half within the pipe and then slide the other half of the sleeve adjacent thereto to form a seal within the pipe. Although a two-piece sleeve  76  is shown, one of skill in the art will appreciate that a sleeve  76  of any number of pieces may be employed without departing from the scope of the invention. Further, the sleeve portions may be associated by way of a living hinge that allows the portions to move relative to each other to facilitate insertion into a pipe. 
         [0039]    Referring now to  FIGS. 9 and 10 , a sleeve  76  of another embodiment of the present invention is shown that is in the form of a coiled or rolled cylinder. It will be appreciated that a coiled cylinder can be placed within a pipe wherein the release of such would allow it to expand so that an outer diameter thereof will snugly engage the inner diameter of the pipe. Although a slight overlap  92  is shown in  FIG. 10 , one of skill in the art will appreciate that the ends of the sleeve  76  may be made to abut after expansion. In addition, the sleeve  76  of this embodiment of the present invention may easily be modified to accommodate pipes of various diameters. After the sleeve  76  is placed within the tube, some embodiments of the present invention are treated with hot or cold water or another fluid containing a chemical that reacts with a chemical impregnated within the sleeve wall. This chemical reaction would expand and/or harden the sleeve  76  to create a tight bond between the outer diameter of the sleeve and the inner diameter of the pipe. 
         [0040]    Referring now to  FIGS. 11-13 , another version of the two-piece sleeve is shown. Here, a first portion  96  of the sleeve is added to the pipe and the a second portion  100  of the sleeve would be interconnected thereto by a sliding engagement. It is envisioned that the sleeve portions somewhat overlap  92  initially to facilitate insertion of the second portion  100  of the sleeve into the pipe. That is, one of skill in the art will appreciate that a secure engagement of the sleeve  76  into the pipe may be very difficult. Thus by providing a second portion  100  of the sleeve that is slightly offset relative to the first inserted portion  96 , insertion of the sleeve  76  is facilitated. With specific reference to  FIG. 11 , the sleeve  76  may be formed in one piece as well, wherein an overlap is provided. In order to completely deploy the sleeve  76 , a tool or fluid pressure is used to expand the second portion  100  of the sleeve relative to the first portion  96  of the sleeve, thereby allowing their respective ends to abut.  FIG. 13  shows a configuration where the ends include a locking member  104  to help ensure that the second portion  100  of the sleeve does not move relative to the first portion  96  of the sleeve. 
         [0041]    The hydrant assembly  10  and associated hardware may be in any faucet assembly. Preferably, the faucet assembly are those manufactured by WCM Industries, Inc., which hold various patents and published patent applications, all of which are incorporated by reference in their entireties herein. For example, the following are incorporated by reference in their entirety herein: U.S. Pat. No. 7,249,609 entitled “Yard hydrant with closure valve check valve”, U.S. Pat. No. 7,111,875 entitled “Wall hydrant with slip clutch assembly”, U.S. Pat. No. 7,100,637 entitled “Wall hydrant having backflow preventor”, RE39,235 entitled “Freezerless wall hydrant for delivery of hot or cold water through a single discharge conduit”, U.S. Pat. No. 7,059,337 entitled “Fluid hydrant”, U.S. Pat. No. 6,948,518 entitled “Escutcheon for wall mounted faucets and hydrants”, U.S. Pat. No. 6,948,509 entitled “Fluid hydrant”, U.S. Pat. No. 6,883,534 entitled “Freeze protection device for wall hydrants/faucets”, U.S. Pat. No. 6,857,442 entitled “Freeze protection device for wall hydrants/faucets”, U.S. Pat. No. 6,830,063 entitled “Freezeless protection device for wall hydrants/faucets”, U.S. Pat. No. 6,805,154 entitled “Freeze protection device for wall hydrants/faucets”, U.S. Pat. No. 6,769,446 entitled “Freeze protection device for wall hydrants/faucets”, U.S. Pat. No. 6,679,473 entitled “Push and turn hydrant for delivery of hot or cold water through a single discharge conduit”, D482,431 entitled “Wall hydrant”, U.S. Pat. No. 6,532,986 entitled “Freeze protection device for wall hydrants/faucets”, D470,915 entitled “Wall hydrant”, U.S. Pat. No. 6,431,204 entitled “Solenoid actuated wall hydrant”, U.S. Pat. No. 6,206,039 entitled “Freezeless wall hydrant for delivery of hot or cold water through a single discharge conduit”, U.S. Pat. No. 6,142,172 entitled “Freeze protection device for wall hydrants/faucets”, U.S. Pat. No. 6,135,359 entitled “Heated yard hydrant”, U.S. Pat. No. 5,813,428 entitled “Combination wall hydrant and backflow preventor”, U.S. Pat. No. 5,701,925 entitled “Sanitary yard hydrant”, U.S. Pat. No. 5,632,303 entitled “Wall water hydrant having backflow and back siphonage preventor”, U.S. Pat. No. 5,590,679 entitled “Wall water hydrant having backflow and back siphonage preventor”, U.S. Pat. No. 5,246,028 entitled “Sanitary yard hydrant”, 20080047615 entitled “Yard hydrant with check valve”, 20080047612 entitled “Automatic draining double check vacuum breaker”, 20080006327 entitled “Hydrant Roof Mount”, 20070095396 entitled “Assembly to mount a hydrant to a roof”, 20070044840 entitled “Motor actuated wall hydrant” 20070044838 entitled “Yard hydrant with closure valve check valve”, 20070039649 entitled “Yard hydrant with drain port air line” 20060254647 entitled “Yard hydrant with drain port check valve”, 20060196561 entitled “Wall hydrant having a backflow preventor”, 20060108804 entitled “Wall hydrant with slip clutch assembly”, 20060086921 entitled “Wall hydrant assembly with a rotatable connector”, 20050067833 entitled “Pipe coupling for joining pipes of varying diameters”, 20050034757 entitled “Freeze protection device for wall hydrants/faucets”, and 20040194395 entitled “Round wall-mounted hydrant housing for freezeless wall hydrants and method of installation thereof”. 
         [0042]    While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims.