Abstract:
A protective vent line cap for protecting sanitary plumbing vent lines is described. The vent line cap includes an open bottom conically flared shroud that attaches to the vent line using a mounting strap having an adjustable strap clamp fastener and a mounting bracket. The mounting bracket is fastened at its top to the shroud and at the bottom to the strap clamp. The vent line cap is designed to be easily installed and removed using common hand tools. The vent line cap prevents foreign material from entering the vent line and subjacent plumbing while still allowing air to flow from the vent line as well as preventing rain water from entering sewer system.

Description:
RELATED APPLICATIONS 
     There are currently no co-pending applications. 
     FIELD OF THE INVENTION 
     The presently disclosed subject matter is directed to plumbing devices. More particularly, the present invention relates to sanitary plumbing vent line caps. 
     BACKGROUND OF THE INVENTION 
     Over the last one hundred twenty-five years (125 y.) or so plumbing has developed into a modern engineering marvel. American cities, suburbs and small towns have implemented a maze of plumbing pipes and pumps that both supply users with potable water from water sources and dispose of water borne waste into sewage systems. 
     The plumbing that removes water borne waste is commonly referred to as the drain-waste-vent (DWV) or sanitary piping system. The sanitary piping system removes sewage and greywater waste from a house or other building. Such waste is produced at toilets, sinks and showers. To prevent the unpleasant smell of sewer gas each sanitary piping fixture is supplied with a water trap, which is a section of pipe, usually containing a “U”-shaped trap filled with water. On one (1) side of the “U” shape traps are waste lines that run to the sewer system while on the other side is living or working spaces. Ideally the water in the “U” shape traps block sewer gas from seeping into the living spaces. 
     While sanitary piping systems work very well, they do have problems. Sewer gases can build up rather high pressures due to biodegrading sewer matter and other causes. Such pressure can cause sewer gases to escape back through the “U” shape traps. This is easily prevented by simply venting the sanitary piping system to atmospheric pressure using a vent line. A common sight on the roof of almost every home or building is the sanitary piping system vent line. Such vent lines release pressure build-up in the sanitary piping system which aids sewage transfer. 
     Properly maintained vent lines work very well. However, since the interior of the pipe is completely open to the environment, foreign objects or materials can easily enter. Items such as twigs, leaves, dirt, trash, and the like can fall or be blown inside, while birds, small animals, and insects can fly, crawl, or become trapped inside. Such materials can accumulate within the vent line, causing it to cease operating properly in that air does not freely enter and leave the vent line. This can result in piping backups and flooding. When such occurs the most realistic fix is to go to the roof and remove objects and blockages. A most unpleasant and dangerous task. 
     Accordingly, there exists a need for a means by which foreign material can be kept out of sanitary pipe vents in an effort to eliminate the problems as described above. Beneficially such a means would be easy to attach using common tools and fasteners and would allow air to readily enter the vent line. Even more beneficially that means would be easily removed to allow access to the vent line if required or if modifications are needed. 
     SUMMARY OF THE INVENTION 
     The principles of the present invention provide for vent line caps that keep foreign materials out of vent lines while still allowing air to readily enter and leave the line. Such vent caps are easily attacked using common tools and fasteners and are easily removed if access to the vent line is required or if modifications are needed. 
     A vent line cap that is in accord with the present invention includes a shroud assembly having an open-bottomed conical side and a generally circular top. The vent line cap further includes a substantially flat strap clamp and an inverted “U”-shaped support bracket having two (2) side legs, each with a bottom strap hook, and an upper horizontal leg that spans between the side legs. The top attaches to the upper horizontal leg while the bottom strap hooks attach to the strap clamp. Beneficially, each strap hook is a “U”-shaped appendage having a narrow vertical slot that is dimensioned to receive and close on the strap clamp as well as a fastener closing each strap hook around the strap clamp to form a rigid union. 
     The vent line cap preferably includes a strap clamp having an integral screw-type tensioner mechanism that interacts with a plurality of parallel apertures. Ideally the screw-type tensioner mechanism can be tightened or released using a common hand tool such as a screwdriver, a nut driver, a wrench, a crescent wrench, a lock wrench or pliers. 
     To properly mount the vent line cap on the top of a vent line, the two (2) side legs each include a horizontally protruding stop. In practice the shroud assembly is comprised of molded plastic or a corrosion resistant metal. A top fastener is used to connect the top to the upper horizontal leg. Because of mounting stress the top fastener should include a washer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is an environmental view of a vent line cap  10  that is in accord with the preferred embodiment of the present invention; 
         FIG. 2  is a front perspective view of the vent line cap  10  shown in  FIG. 1 ; and, 
         FIG. 3  is an upward-looking view of the vent line cap  10  shown in  FIGS. 1 and 2 . 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  vent line cap 
               20  shroud assembly 
               22  side 
               24  top 
               50  strap clamp 
               52  tensioner mechanism 
               54  aperture 
               70  support bracket 
               72  strap hook 
               73  side leg 
               74  stop 
               75  upper horizontal leg 
               90  first fastener 
               92  second fastener 
               94  washer 
               100  building structure 
               105  vent line 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 3 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The principles of the invention provide for a preferred embodiment vent line cap  10  which protects existing sanitary plumbing vent lines from debris while allowing proper operation and easy installation and removal.  FIG. 1  shows an environmental view of the vent line cap  10 . The vent line cap  10  is placed at the open end of an existing vent line  105 , which will usually be near where the vent line  105  exits the roof of a building  100 , such as a house, an apartment building, a commercial building, or most other buildings having plumbing. In practice, the vent line cap  10  will be made available in a variety of diameters to properly mate with the outer diameters of various standard vent lines  105 . 
     As shown in  FIG. 1  the vent line cap  10  includes a molded shroud assembly  20  and a substantially flat strap clamp  50  that encircles the vent line  105 . The strap clamp  50  is used to attach the vent line cap  10  to the vent line  105 , beneficially using only common tools and such that the vent line cap  10  is rigidly fixed to the vent line  105 , but readily removed if desired. The shroud assembly  20  covers the vent line  105  opening, preventing foreign materials such as twigs, leaves, small animals, birds, or the like from gaining entrance to the vent line  105  and subjacent plumbing while still allowing air to freely enter or exit the vent line  105 . 
       FIG. 2  provides a front perspective view of the vent line cap  10 . The vent line cap  10  includes the shroud assembly  20 , the strap clamp  50 , and a support bracket  70 . The shroud assembly  20  has an open-bottomed, cone-segment-shaped cross-section that is formed by an outward flaring side  22  and a generally circular top  24 . The top  24  attaches to the top part of the support bracket  70  as described subsequently. Beneficially the shroud assembly  20  is comprised of a molded plastic such as polyvinyl chloride (PVC), fiberglass, a composite plastic, or alternately a metal such as painted, galvanized, or otherwise plated steel, stainless steel, or another corrosion resistant metal. Since the vent line cap  10  is envisioned as being available in a plurality of diameters to mate with different sized vent lines  105 , the shroud assembly  20 , strap clamp  50 , and support bracket  70  should be appropriately dimensioned. 
     Still referring to  FIG. 2  the support bracket  70  is an inverted “U”-shaped unitary structure preferably made from formed, molded, or extruded flat stock material about one-half inch (½ in.) wide. This will provide the required structural strength to withstand high winds and other environmental stresses that the vent line cap  10  may experience. The support bracket  70  has two (2) integral strap hooks  72  that are located at the bottom ends of two (2) side legs  73  of the support bracket  70 . Each strap hook  72  is formed into a “U”-shaped appendage having a narrow vertical slot that is dimensioned to receive flat sections of the strap clamp  50 . When the strap clamp  50  is in the strap hooks  72  those hooks are closed around the strap clamp  50  using first fasteners  90  such as a rivet, screw, bolt, or the like so as to form a relatively rigid union. 
     The support bracket  70  further comprises two opposing integral stops  74  that protrude inward from intermediate positions of the two side legs  73 . The stops  74  are horizontal appendages approximately one inch (1 in.) in length configured to rest on the top of the vent line  105  so as to vertically position the vent line cap  10  on the vent line  105 . 
     The two (2) side legs  73  continue past the stops  74  to an upper horizontal leg  75  that connects to the two (2) side legs  73 , thus completing the inverted “U” shape of the support bracket  70 . The top  24  of the shroud assembly  20  is fastened at the center of the upper horizontal leg  75  using at least one (1) second fastener  92  having a washer  94 . The second fastener  92  is envisioned as being a rivet, screw, bolt, or the like, while the support bracket  70  is envisioned as being a rugged corrosion resistant material such as stainless steel, composite plastic, or an equivalent material capable of withstanding environmental stresses encountered on a building  100  roof. 
       FIG. 3  presents an upward-looking view of the vent line cap  10 . The strap clamp  50  is routed through the strap hooks  72  of the strap bracket  70 . This forms a guided circular clamp suitable for mating with the top of the vent line  105 . With the strap clamp  50  routed through the strap hooks  72  the strap clamp  50  can be tightened using a conventional integral screw-type tensioner mechanism  52 . The tensioner mechanism  52  engages and works in conjunction with a plurality of parallel vertical apertures  54  formed in the strap clamp  50  to enable tightening around the vent line  105  using a common screw or nut driver. 
     It is envisioned that many other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention. While only one particular configuration is shown and described it is for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the vent line cap  10  it would be installed as suggested in  FIG. 1 . The method of installing and utilizing the vent line cap  10  may be achieved by performing the following steps: procuring a model of the vent line cap  10  having shroud assembly  20 , strap clamp  50 , and support bracket  70  which provide an inner diameter suitable for fitting over the outer diameter of an existing vent line  105 ; loosening the tensioner mechanism  52  using a common driver, if needed; inserting the strap clamp  50  over the end portion of the vent line  105  until the stops  74  of the support bracket  70  contact the top of the vent line  105 ; tightening the strap clamp  50  around the vent line  105  by rotating the tensioner mechanism  52  to obtain a tight fit with the vent line  105 ; and, benefiting from prevention of foreign material such as twigs or leaves, from entering the vent line  105  while using the vent line cap  10 . 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.