Patent Publication Number: US-2006010786-A1

Title: Roof snow stop

Description:
BACKGROUND  
      1. Field of Invention  
      The field of the Invention is a group of devices of widely varying shape, or complexity or cost etc. designed to prevent snow and ice from sliding off an inclined roof in snowy climates.  
      2. Description of Prior Art  
      There are a number of devices covered by design patents, which cover only the ornamental or aesthetic aspect of the device, which devices are intended to prevent snow and ice from sliding off an inclined roof Representative of such patents are U.S. design Pat. No. 351,989, Nov. 1, 1994 to R. M. Cline; U.S. design Pat. No. 364,338, Nov. 21, 1995 to R. M. Cline; and U.S. design Pat. No. 372,421, Aug. 6, 1996 to R. M. Cline. These design patents by definition do not cover any function or structure of the device, but only their ornamental appearance. These devices appear to have shapes which would not be very effective in retaining snow and ice on a roof or which would be difficult to install on the roof, or would not be structurally strong in terms of retaining significant amounts of ice and snow. U.S. Pat. No. 5,205,088, Apr. 27, 1993, to G. B. Mueller, describes a roofing panel with certain shapes molded therein and designed to prevent snow and ice from sliding down a roof U.S. Pat. No. 5,282,340, Feb. 1, 1994, to R. M. Cline, discloses a butterfly-shaped device for mounting on a roof to retain snow and ice, involving a slot to receive a roof seam, and held to the seam by set screws. U.S. Pat. No. 5,669,184, Sep. 23, 1997 to T. E. Anderson, describes a snow bracket with an elongated body with a number of bent metal parts. Other patents such as U.S. Pat. No. 5,711,114, Jan. 27, 1998, to G. B. Mueller; U.S. Pat. No. 6,536,166, Mar. 25, 2003, to F. W. Alley; U.S. Publication Ser. No. 2003/0066247, Apr. 10, 2003, by T. P. Trevorrow—all disclose much more complicated devices for retaining snow and ice on roofs, and which are more complicated to attach to roofs.  
      The Inventor works at elevations from between 5,000 to 11,400 feet in the Colorado Rockies where there are some of the greatest roof snow loads in the country. If left alone the snow loads on a roof will break loose and slide like an avalanche causing property damage and personal injury or death. Snow and ice weighing thousands of pounds can drop from roofs onto walkways and building entrances thus giving rise to expensive liability. Snow and ice can cause property damage when falling from one roof to another, thus breaking roofs, plywood, and rafters. They can also knock decks away from buildings, crush cars, rip off railings, and crush walls that are located on adjacent buildings, and can break windows and cause other damage to adjacent buildings. The Inventor has installed various types of snow and ice holding systems and knows their drawbacks. The snow fence is the most commonly used device. It can be made from different metals or alloys. Generally it has a post that rises a foot above the roof with two holes in it and is screwed down to the roof through a 12 inch base. Snow fence posts are installed in a line every four feet along the eave of the roof. Pipes are then put through the holes connecting the upright and completing the fence. The fence holds the snow on the roof, but there are drawbacks. The ice becomes very heavy along the eave, which can cause leaking. If the roof slope above the snow fence is 10 to 60 feet long, the snow will creep down to the fence putting all the snow load on the eave of the building, and over time the snow buildup will cause the snow fence to rip off the roof and crash to the ground, likely causing damage.  
      Another common snow and ice holder is a product that attaches to metal roofs. Essentially it is a rectangular metal plate that bolts to a metal rib in a metal roof. It is made of expensive alloys such as copper, brass, aluminum, etc. It is attached to the vertical seams of the roof by ratcheting a tight screw against the seam of the roof. The product does not attach to the roof sheeting, and generally pulls out and rips the metal roof seems, and falls to the ground.  
     SUMMARY OF INVENTION  
      The Invention of the Application is a simple generally L-shaped device of varying lengths which attaches to an inclined roof surface in order to prevent snow and ice from falling off the roof and harming persons or property below the roof. For very steep roofs, the device would have more of a V-shape when looked at from the side, so that the base member could be mounted parallel to the roof, yet the vertical member would be substantially perpendicular to the roof.  
     OBJECTS AND ADVANTAGES  
      The objects of the present Invention are: 
          1. To provide a simple and inexpensive device for retaining ice and snow on inclined roof surfaces in snowy climates.     2. To provide a device for retaining ice and snow which is extremely simple and inexpensive to manufacture.     3. To provide such a device which is extremely simple to install on a slanted roof.     4. To provide a device which can be made in transparent form to minimize its visibility on a roof.     5. To provide a device which can be made in colors to match the color of a roof in order to minimize visibility on the roof, or which may be easily made to be black or white or transparent.     6. To provide a device which is extremely inexpensive to make in large quantities by plastic injection molding.     7. To provide a device which is extremely inexpensive when made of common plastics.     8. To provide a device the dimensions of which can be easily modified in order to be easily adapted to roofs of varying incline, and climates with light, moderate, or heavy snowfall.     9. To provide a device which has sufficient strength due to its shape and material, in order to be able to retain significant masses and weights of snow or ice.     10. To provide a device with shape and surface features well adapted to retain snow and ice, and which sufficiently engages snow or ice under melting conditions to prevent them from falling off the roof.     11. To provide a device which could be made from a number of inexpensive plastics.     12. To provide a device for retaining snow and ice with a shape easily adapted to various decorative patterns, and to harmonize with the general architecture of the building.     13. To provide a device of simple concept adapted to be used in many varying lengths on a roof as required by the shape and dimensions of the roof.     14. To provide a device for retaining snow and ice safely during storms cycles, so that maintenance and snow and ice removal can be done at a later date.     15. To provide a device that will not cause damage or water leaks to the interior of a building.     16. To provide a device that can be installed with caulking and two screws and can hold 300 pounds of snow and ice per device on a roof.     17. To provide a device that retains snow and ice evenly over the entire roof, thus keeping the weight of the snow and ice (snow load) evenly distributed over the roof so that snow and ice are not just held at the eave.     18. To provide a device that retains snow and ice over the entire roof so that snow does not slide into a roof valley and damage or rip the valley apart, or knock down chimneys or plumbing vents from the roof.     19. To provide a device that helps retain snow and ice on roofs to protect walkways and entrances to buildings below to reduce injury and bodily harm to the people below.     20. To provide a device that holds snow and ice on roofs thus protecting automobiles in driveways and windows on neighboring or adjoining buildings, and avoiding other property damage that may occur due to failing snow and ice.       

    
    
     DRAWING FIGURES  
       FIG. 1  is a top view of the device showing mounting feet  1 , which are attached to the roof and a vertical snow retaining vertical member  4  designed to retain snow and ice.  
       FIG. 2  is a side view of the device showing the mounting feet  1 , the vertical snow retaining member  4 , and angle reinforcement  3 .  
       FIG. 3  is a front view of the device showing the surface of snow retaining member  4  which retains the snow and ice and prevents it from sliding down the roof.  
       FIG. 4  is a side view showing one of the devices mounted on an inclined roof surface, and  
       FIG. 5  is a view looking down on several devices mounted across the inclined surface of a roof, in several lines of devices. 
    
    
     REFERENCE NUMERALS IN DRAWINGS  
       1 . mounting feet  
       2 . roof attachment holes  
       3 . angle reinforcement  
       4 . snow retaining member  
       5 . gripping shapes  
       6 . bracket angle  
       7 . roof  
       8 . fastener  
     DETAILED DESCIPTION OF THE DRAWINGS  
       FIG. 1  is a top view of the device, showing a base member comprised of mounting feet  1  which are positioned flush with the roof surface, and which are attached to the roof by means of screws or nails or other fasteners, which pass through the roof attachment holes  2  and into the roof material, or other roof attachment means. Part  4  is the snow retaining member, or vertical member, which is attached to the base member, and which extends upwardly from the base member or mounting feet  1  and the surface of the roof, and which blocks the downward motion of snow and ice because the snow and ice press against the up-roof surface of snow retaining member  4 . Parts  3  are shown in an edge on view, and they are the angle reinforcements or brace members, or other strengthening means, typically in the shape of a triangle the base of which is attached to mounting feet  1  and the vertical side of which is attached to snow retaining member  4 .  
       FIG. 2  is a side view of the device showing its general L-shape and showing mounting foot  1 , angle reinforcement  3  in the shape of a triangle, snow retaining member  4 , and gripping shapes  5 .  
       FIG. 3  is a front view of snow retaining member  4  which includes gripping shapes  5  on its surface. Gripping shapes  5  are designed to retain snow and ice by penetrating into the snow and ice when the snow and ice is initially deposited on the roof, or when they melt and refreeze on the roof Snow retaining member  4  is also shown and mounting feet  1  and angle reinforcement  3  are shown in phantom form on the other side of this front surface of snow retaining member  4 .  
       FIG. 4  shows the Invention mounted on an inclined roof  7 . Fastener  8  (for example a bolt or screw-not part of the Invention) is shown holding the Invention on the roof  7 .  
       FIG. 5  shows rows of the Inventions on an inclined roof.  
     DESCRIPTION—PREFERRED EMBODIMENT  
      The preferred embodiment of the device is shown in  FIGS. 1 through 3 , which show a simple L-shaped device where the snow retaining member  4  is generally perpendicular to mounting feet  1  (unless at an obtuse bracket angle for a steep roof) and is generally semicircular in shape. For added strength, the preferred embodiment has angle reinforcements  3  which make snow retaining member  4  stronger and less likely to bend or break in the direction down an inclined roof, under the weight of snow and ice. The preferred embodiment is easily made out of several kinds of plastics, including polycarbonate plastic, by a fairly simple injection molding process known to those skilled in the art, since the overall shape of the device is fairly simple. The gripping shapes  5  in the preferred embodiment could be square based pyramids, although many other shapes projecting perpendicularly and outwardly from the snow retaining member  4  and into the snow and ice, could be used.  
      For many inclined roofs, the device would have bracket angle  6  equal to approximately 90 degrees, but for steeply inclined roofs the angle could be greater than 90 degrees. The mounting feet  1  could be in the range of two to three inches in length and in the range of ¼ inch thick. The snow retaining member  4  would also typically be about ¼ inch thick and approximately three inches high. The thickness of angle reinforcement  3  would also be approximately ¼ inch. These thicknesses could vary with the strength of the plastic. The gripping shapes  5  would extend outwardly from the front of snow retaining member  4  by approximately ¼ inch. The width of mounting feet  1  would be approximately one inch, and the space between the two mounting feet would be approximately 1½ inches, with the entire length of snow retaining member  4  being approximately 5 inches. Mounting feet  1  could extend from the edges of snow retaining member  4  by approximately one inch. Roof attachment holes  2  in mounting feet  1  could be positioned approximately one-half inch back from snow retaining member  4 . The preferred embodiment of the device would be made from polycarbonate plastic or other plastics well adapted to injection molding, although other types of plastic such as styrene, etc., all well known to those skilled in the art, could be used. Caulking around the fasteners  8  and roof attachment holes  2  is recommended.  
     OPERATION OF THE INVENTION  
      The device is mounted on an inclined roof so that the mounting feet  1  are flush with the roof surface and pointing down the incline of the roof, and so that the snow retaining member  4  extends generally vertically above the roof, and so that a line drawn perpendicular to snow retaining member  4  would point parallel to the inclined roof surface and up the inclined roof surface. The snow retaining member  4  containing the gripping shapes  5  is pointed up the inclined roof. Several of these L-shaped devices may be positioned in a horizontal line generally parallel to the bottom edge of the roof, or in a staggered arrangement in several lines across the incline surface of the roof so that the snow retaining member  4  surfaces are positioned perpendicular to the incline plane of the roof. Generally, bracket angle  6  would be approximately 90 degrees; however, for very steep roofs, the bracket angle  6  may be an obtuse angle of more than 90 degrees so that that snow retaining member  4  is generally vertical to the ground, so that on very steep roofs, the snow and ice would not have a tendency to move up and over snow retaining member  4 . One or more of the devices can be easily mounted on a roof by means of bolts or screws or similar fastening means inserted in roof attachment holes  2  in mounting feet  1 , and then into the roof material.  
     Tests  
      The snow and ice holder of the present Invention has been installed and tested in the Town of Telluride, Colo. which has an elevation of 8,745 feet and an annual snowfall of 300 inches. The installation was as follows. On a 12/12 pitch roof or a 45 degree roof, caulk both feet of the device and screw two screws into each of the two feet with a 2 inch long by 5/16 inch wide self-tapping metal screw with a neoprene washer, using a cordless drill, into the roofing and sheeting of the roof. Install a line of snow and ice holders along the bottom eave leaving a one foot gap between holders. Move up the roof five feet and repeat the installation, until reaching the peak of the roof. This snow and ice holder with this installation has held eight feet of snow. By having many contacts all over the roof, more surface resistance is created, and the area of the snow load is spread over the entire structure, making for a safe snow pack. All the weight of the snow cannot move to the bottom of the roof. This keeps valleys from being torn up by the downward force of snow and ice, which snow fencing does not protect against. The chimneys and plumbing vents in the roof remain in place.  
      The simple polycarbonate product of the present Invention is easy to install, weighs only a couple of ounces, is compact, and has not broken in everyday use in an extreme climate with strong ultraviolet light. It also has a very attractive oval shape with a smooth surface. It blends with the roof and involves no intrusive fixtures. It can be made in unlimited colors to be beautiful on any roof. The strength of the product, its holding ability of ice and snow, and the timeless durability of polycarbonate plastic are major advantages. The polycarbonate plastic should out last any roof system or any roof product. The Inventor believes that the product is much better than anything available currently on the market, and that it will provide a safe environment for people and property and will prolong the life of the roof.  
     Additional Embodiments  
      The L-shaped device could be made of several parts attached to each other by welding, brazing, or adhesives, or it could be molded or stamped from one piece of metal or plastic or similar strong material. A number of variations of the size and shape of the device are possible including mounting feet  1  which are wider than approximately one inch or longer than approximately two inches, snow retaining members  4  which are taller or shorter than 3 inches. For very steeply inclined roofs, bracket angle  6  could be substantially more than 90 degrees so that snow retaining member  4  would be more nearly perpendicular to the ground so as to reduce the likelihood that snow and ice could slide over snow retaining member  4  and down the inclined roof. The device could have a snow retaining member  4  substantially longer than about five inches, in order to extend over a longer distance over the roof and could have more than two mounting feet, preferably at least one mounting foot for every 6 to 12 inches of length across the roof Each mounting foot  1  could have more than one roof attachment hole  2 , in order to provide a more secure mounting of the device on the roof in cases where the roof is more steeply inclined and in climates where the device must support a greater depth of snow and ice, in which case the height of snow retaining member  4  could be substantially higher than three inches in order to retain a thicker layer of snow and ice. Another variation of the device would be a device with a snow retaining member  4  of substantially greater length and with numerous mounting feet  1 , molded in one piece, but containing lines of weakness in snow retaining member  4  so that a very long device could be broken up into several portions each with their mounting feet  1 , to accommodate roofing surfaces of varying widths. Additional embodiments might incorporate gripping shapes  5  in forms other than square pyramids such as triangular pyramids, rods, cones triangles or polygons projecting vertically from the front surface of snow retaining member  4 . While such shapes, being sharper, may increase the risk of injury to the installer, the shapes might better retain snow and ice. As previously mentioned, the plastic out of which the device is made could be transparent in order to be of low visibility on the roof, or it could be white or black or many other colors selected to match the color of the roof, in order to reduce visibility of the device on the roof. It could also be transparent; or opaque and black, white, or colored. In addition to being semicircular in shape, the snow retaining member  4  could be rectangular, half oval, or in the shape of many different polygons or oval shapes. Depending on the exact type of plastic used for the device, the device may also included various chemicals adapted to prevent the device from being degraded by ultraviolet radiation, or becoming brittle or discolored, etc. These types of plastic additives are well known to those skilled in the art.  
     Alternative Embodiments  
      In addition to being made of polycarbonate, styrene, ABS high impact plastic or rigid polyvinyl chloride plastic could be used. In addition to being made out of molded plastic, the device could be made from metals of various kinds, by stamping or cutting from a metal sheet of suitable shape. It could also be made of cast metal  
     CONCLUSIONS, RAMIFICATIONS AND SCOPE  
      A number of changes are possible to the shape, size, and exact configuration of the device described above while still remaining within the scope and spirit of the Invention. The specifics about the form of the Invention described in this application are not intended to be limiting in scope. The scope of the Invention is to be determined by the claims and their legal equivalents, not the examples given above.