Abstract:
An enclosure system for providing a visual barrier with respect to various objects, including a tank of the type used to store fuel, water and other liquid and gaseous materials. The enclosure system includes an enclosure and a lid covering the enclosure. The enclosure is attached to the tank and is made from opaque materials such as wood or dyed plastic. Vent openings are provided to prevent the accumulation of undesirable vapors, e.g., fuel vapors, that may escape from the tank and accumulate between the enclosure and the tank. An attachment mechanism is provided for supporting the enclosure in a predetermined position relative to the tank, e.g., so that the bottom of the enclosure is positioned a few inches above the surface on which the tank rests. An optional second attachment mechanism is provided for ensuring the enclosure remains so positioned relative to the tank.

Description:
RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 08/939,433, filed Sep. 26, 1997, now U.S. Pat. No. 6,102,230. 
    
    
     FIELD OF THE INVENTION 
     The present invention pertains to enclosures providing a visual barrier for fuel and other tanks, and for other objects which are unsightly or otherwise need to be visually screened. 
     BACKGROUND OF THE INVENTION 
     Tanks are often positioned outside residential and commercial structures for storing fuel, water and other liquids and gases. For example, propane used for cooking, heating and other purposes is often stored in a tank positioned next to an exterior wall of a structure. 
     While necessary to the operation and activity within the structure, such tanks are often relatively unsightly. As a result, vegetation is often planted to provide a visual barrier with respect to the tank. However, vegetation often does not provide a suitable visual barrier, and can impede access to the tank for delivery and maintenance. Sometimes, home and business owners erect a stockade or other fence around the tank to provide a visual barrier. The cost and time associated with installing such a fence, and the restriction to tank access the fence imposes, makes this approach to tank screening less than optimal. In some cases, the appearance of a tank near a structure may be a sufficiently negative proposition that individuals will refuse to install a tank even when needed. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a device for providing visual screening of a storage tank positioned relative to an adjacent surface. The storage tank includes a vertical sidewall having a cylindrical outer surface and an upper end. The storage tank further includes an upper end wall attached to the vertical sidewall at the upper end thereof and located radially inward from the outer surface of the sidewall. 
     The device comprises a screening structure for surrounding the storage tank. The screening structure has an upper end, a lower end, an inner surface extending between the upper and lower ends and at least one opening extending through the screening structure. At least a portion of the inner surface is for confronting the vertical sidewall of the storage tank when the screening structure surrounds the storage tank. The at least one opening is located entirely between a horizontal plane defined by the upper end of the vertical sidewall of the storage tank and the upper end of the screening structure when the screening structure surrounds the storage tank. The device further comprises a support that engages the screening structure and the upper end wall of the storage tank when the screening structure surrounds the storage tank. The support prevents the screening structure from moving vertically downward relative to the storage tank such that the lower end of the screening structure is maintained in vertical spaced-apart relationship to the adjacent surface. 
     In another aspect, the present invention is directed to a system comprising a storage tank including a vertical sidewall having a cylindrical outer surface and an upper end. The storage tank further includes an upper end wall attached to the vertical sidewall at the upper end thereof and located radially inward from the outer surface of said sidewall. A screening structure surrounds the storage tank. The screening structure has an upper end located upward of the upper end of the vertical sidewall, a lower end, an inner surface extending between the upper and lower ends and at least one opening extending through the screening structure. At least a portion of the inner surface confronts the outer surface of the vertical sidewall. The at least one opening is located entirely between a horizontal plane defined by the upper end of the vertical sidewall and the upper end of the screening structure. A support engages the screening structure and the upper end of said storage tank. The support preventing the screening structure from moving vertically downward relative to the storage tank such that the lower end of the screening structure is maintained in spaced-apart relationship to a surface located below the lower end. 
     In yet another aspect, the present invention is directed to a device for providing visual screening of a storage tank positioned relative to an adjacent surface. The storage tank includes a vertical sidewall having a cylindrical outer surface and an upper end. The storage tank further includes an upper end wall attached to the vertical sidewall at the upper end of the sidewall. 
     The device comprises a screening structure for surrounding the storage tank. The screening structure has an upper end, a lower end, a first edge and a second edge. The screening structure is flexible so as to be movable between (i) a first position where the screening structure is positioned around the tank and the first and second edges are located proximate one another and (ii) a second position wherein the first and second vertical ends are spaced apart from one another. A clamp is provided for holding the first and second edges in the first position. A support engages the screening structure and the upper end wall of the storage tank when the first and second edges are in the first and said second positions. The support prevents the screening structure from moving vertically downward relative to the storage tank when the first and second edges are in the first and the second positions such that the lower end of the screening structure is maintained in vertical spaced-apart relationship to the adjacent surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation view of the enclosure system of the present invention and the bottom portion of the tank the enclosure system surrounds, with remaining portions of the tank being shown in phantom view; 
     FIG. 2 is a side elevation view of a vertical cross section of the enclosure system of FIG. 1 taken along line  2 — 2  in FIG. 6, with the tank surrounded by the enclosure being shown in solid view; 
     FIG. 3 is top view of the inner surface of the enclosure, spread out flat on a surface, with an intermediate portion of the enclosure being removed to facilitate illustration; 
     FIG. 4 is a side elevation view of one stave of the enclosure illustrating spacers used to space the enclosure from the tank; 
     FIG. 5 is a partial cross section of the enclosure taken at line  5 — 5  in FIG. 1, illustrating details of the clamp used to secure together confronting edges of the enclosure, with adjacent portions of the tank being shown in a partial top view; 
     FIG. 6 is top view of the enclosure system of FIG. 1, with the lid removed to reveal the tank; 
     FIG. 7 is a partial side elevation view of the tank enclosure illustrating details of the strap and hook to secure the enclosure to the tank; 
     FIG. 8 is an exploded perspective view of the enclosure and lid; and 
     FIG. 9 is a cross-sectional side elevation view of another embodiment of the lid. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, the present invention is an enclosure system  20  for providing a visual barrier relative to a tank or other object. 
     In a preferred embodiment of the invention, as described below, system  20  is designed to provide a visual barrier relative to a conventional liquid propane gas (“LPG”) or propane tank  30  of the type sized to hold about 420 pounds of LPG or propane, and identified by the label DOT 4BW240. As is known, tank  30  includes a central cylindrical section  32  having an outer surface  33 , a top portion  34  and a curved shoulder  36  connecting the top and cylindrical sections. Tank  30  also includes hollow cylindrical housing  38  attached to and extending upwardly from top portion  34 , and cap  40  hinged to the housing. By opening cap  40 , access may be obtained to the fill and pressure relief valves (not shown), gauges (not shown) and other components of tank  30  enclosed by housing  38  and cap  40 . Typically, four openings  42  are provided in housing  38  immediately above the intersection of the housing with top portion  34 , each spaced 90° from adjacent openings. Tank  30  is positioned on surface  50 . 
     Enclosure system  20  may also be used to enclose other tanks, and more generally almost any elongate structure of cylindrical or other configuration. For example, enclosure system  20  may be used to enclose a tank for storing water, a well head or a concrete pylon. 
     Enclosure system  20  comprises enclosure  100  and lid  200 . Enclosure  100  is designed to surround tank  30  and lid  200  is positioned on top of the enclosure. While the use of lid  200  is preferred, it is not an essential element of enclosure system  20 . 
     In a preferred embodiment, enclosure  100  has a plurality of staves  102  which are preferably made from an opaque or translucent material that is weather resistant, has sufficient mechanical strength, and has a pleasing visual appearance. Suitable materials for staves  102  include rot-resistant woods (as depicted by stave  102 ′ in FIG. 5) such as cedar and redwood, plastics (as depicted by stave  102 ″ in FIG. 5) such as polyethylene, polyurethane and ABS, and wood-polymer composites of the type sold under the trademark TREX by Trex Co. LLC of Winchester, Va. Staves  102  are positioned relative to one another so that little, if any, gap exists between adjacent staves. In one embodiment of the invention staves  102  are white cedar, are about 4 feet long, and have a nominal cross section of 1 inch by 4 inch. 
     Referring to FIGS. 1,  2  and  5 , the number of staves  102  used is selected so that the circumference of enclosure  100  is preferably slightly less, i.e., about the width of one stave, than the circumference of tank  300 . As a result of sizing enclosure  100  in this manner, a vertical opening  124  (see FIG. 5) exists between confronting staves  102 ′ and  102 ″ for the purpose of accommodating slight variations in the nominally standard circumference of tank  30 . 
     Alternatively, enclosure  100  may be made from a single sheet of material that is opaque or translucent, e.g., polypropylene, polyurethane, polyethylene or ABS. When made from such material, enclosure  100  may be made from a flexible material that can be wrapped around tank  30 , or may be made molded in a cylindrical configuration corresponding to that of the tank. In the latter case, enclosure  100  is positioned over tank  30 , rather than being wrapped around the tank. Several pieces of material may also be used to make enclosure  100 . The specific size and configuration of enclosure  100  is dictated by the size and configuration of the object to be enclosed. 
     When enclosure  100  is used to enclose a tank  30  containing LPG or propane, a number of vents  110  are provided extending through staves  102 . Vents  110  are provided to prevent the accumulation of gases that may escape from tank  30  in the region enclosed by system  20 . The size, number and placement of vents  110  are selected so as to prevent such accumulation of gases in such region and to comply with any relevant LPG, propane or other industry standards. For example, the International Approval Services is adopting a standard for tank enclosures identified by “IAS U.S. 3-96 LP Tank Enclosure,” that specifies the area of vents that must be provided in tank enclosures. 
     In a preferred embodiment of the invention, vents  110  are provided in staves  102   a , which are separated from one another by ventless staves  102   b . Thus, in the preferred embodiment every other stave  102  includes a vent  110 . It is believed to be advantageous to position vents  110  so as to be substantially vertically aligned just above the bottom portion of shoulder  36  of tank  30  when enclosure  100  is positioned relative to the tank in the manner illustrated in FIGS. 1 and 2, as described in more detail below. However, other placement of vents  110  will also provide satisfactory results. In this regard, vents  110  need not be horizontally aligned in the manner shown in FIG.  1 . In any event, if tank  30  contains explosive gases, it is recommended that vents  110  be positioned so as to be vertically aligned with that portion of tank  30  between the bottom of shoulder  36  and the top of housing  38 . If enclosure  100  is used in connection with tanks not containing explosive gases, vents  110  may be placed at almost any location on enclosure  100 . 
     Also in the preferred embodiment, vents  110  are sized so that the total area of (a) vents  110  and (b) the open circumferential space between the bottom of enclosure  100  and surface  50 , is equal to or greater than about 1 square inch for each pound of gas that can be stored in tank  30 . Preferably, at least 50% of this total area is provided below the bottom of enclosure  100 . For example, if tank  30  can hold 420 pounds of LPG or propane, the total area of vents  110  and the open circumferential space between the bottom of enclosure  100  and surface  50  should be at least 420 square inches with at least 210 square inches of this area provided below the bottom of enclosure  100 . Thus, the total area of vents  110  is preferably about 0.1 to 0.5 square inches times the magnitude of the weight in pounds of propane or liquid natural gas that can be accommodated in tank  30  when full. For example, if tank  100  can hold 420 pounds of propane, the total area of vents  110  is preferably 42 to 210 square inches (0.1-0.5×420). More information concerning the placement and size of vents  110  is provided below, following the description of installation of the invention. 
     Turning now to FIGS. 1,  3  and  4 , in the preferred embodiment adjacent staves  102  touch one another or are separated by a minimal amount, e.g., {fraction (1/32)} to ½ inch. Staves  102  may be secured together using a variety of techniques so that enclosure  100  has a cylindrical configuration corresponding to that of tank  30  or so that, as illustrated in FIG. 3, the enclosure is substantially planar and maybe wrapped around the tank. These techniques include securing staves  102  together with rigid or flexible fasteners, bands or brackets, gluing the staves together, or keying the staves together with dovetail joints or other interlocking structure. 
     Preferably, as illustrated in FIG. 3, staves  102  are secured together with flexible bands  112  extending roughly perpendicular to the long dimension of the staves. Bands  112  are preferably made from rot and stretch-resistant materials such as nylon, polypropylene or polyethylene. Bands  112  are attached to staves  102  using fasteners such as nails, screws or staples  113  (only several of which are shown in FIG. 3 for clarity of illustration) the latter being preferred at the rate of two staples per stave. The number of bands  112  used depends on the width of the bands, the height of enclosure  100  and the desired structural integrity of the enclosure. In the embodiment of the invention illustrated in FIG. 3, six bands  112  are used, each about ¾ inch wide. Bands  112  should be fairly evenly distributed over the length of enclosure  100 , although it is preferred that a band be positioned about 4-6 inches from top end  114  and bottom end  116  of the enclosure, and two bands be positioned in the region between vents  110  and top end  114  of enclosure  100 . 
     Referring next to FIGS. 1-5, under certain atmospheric conditions, moisture may condense on the outer surface of tank  30 . This moisture, if held against tank  30  by enclosure  100 , may cause the tank to corrode and could degrade the enclosure. To prevent this problem, a plurality of spacers  120  (FIGS. 2-5) are preferably attached to inner surface  122  of staves  102 . Spacers  120  hold inner surface  122  away from outer surface  33  of cylindrical section  32  of tank  30  so as to create a space between surfaces  122  and  33 . The height H (FIG. 4) of spacers  120  may range from {fraction (1/16)} to 2 inches, preferably ¼ to ¾ inch. However, if spacers  120  are made from a compressible material, then height H will need to be somewhat greater than these dimensions so that when enclosure  100  is wrapped around tank  30  as illustrated in FIG.  1  and described below, spacers  120  have a height in the {fraction (1/16)} to 2 inch range. Plastic, rubber and other non-absorbent, moisture-resistant materials may be used for spacers  120 . Spacers  120  may be made from strips of material extending substantially perpendicular to the long dimension of staves  102 , from “buttons” of material attached to inner surface  122  of staves  120  so as to collectively extend in such perpendicular direction, or from material of other configuration. 
     Referring now to FIGS. 1,  3  and  5 , when enclosure  100  is designed as a flexible structure that can be wrapped around tank  30 , as illustrated in these figures, at least one clamp  130  is provided for securing together outermost staves  102 ′ and  102 ″ (see FIGS. 3 and 5) in confronting relation. Clamp  130  may have a variety of designs, although it is preferred the clamp be capable of pulling together and holding together staves  102 ′ and  102 ″ in the confronting relation illustrated in FIGS. 1,  5 ,  6  and  8 . In a preferred embodiment, bracket  130  is a modified worm gear clamp having rack portion  132  and a pinion portion  134 . Rack portion  132  has a flat portion  136  with a plurality of slots  138  formed therein. Pinion portion  134  includes a housing  140  having a pinion gear (not shown) to which screw head  142  is attached. The teeth (not shown) of pinion gear are designed to engage slots  138  in flat portion  136  so that when screw head  142  is turned, flat portion  136  is drawn into and through housing  140 . 
     Rack portion  132  includes a U-shaped portion  144  (see FIG. 5) and rack portion  134  includes a U-shaped portion  146  (see FIG.  5 ). U-shaped portions  144  and  146  are configured to wrap around, respectively, edge  150  (see FIG. 5) of stave  102 ′ and edge  152  (see FIG. 5) of stave  102 ″. Preferably, but not necessarily, U-shaped portions  144  and  146  are secured to staves  102 ′ and  102 ″ (see FIG.  3 ), respectively. In a preferred embodiment, two clamps  130  are provided, one positioned near the middle of enclosure  100 , as measured between upper end  114  and lower end  116 , and the other positioned about 6-12 inches above bottom end  116 . In this embodiment, spacers  120  are substantially vertically aligned with clamps  130 . 
     Enclosure system  20  may optionally include a support system for supporting bottom end  116  of enclosure  100  at a predetermined distance, e.g., 4-6 inches above surface  50 , as illustrated in FIG.  2  and described in more detail below. This support system may consist of one of a number of different devices. For example, the system may include (a) one or more blocks (not shown) positioned on surface  50 , with bottom edge  116  of enclosure  100  resting on such blocks, (b) magnets (not shown) secured to staves  102  so as to support enclosure  100  by magnetic engagement with tank  30  when the latter is made from steel, and (c) a hook, strap and buckle support system, the latter being preferred. 
     Referring now to FIGS. 2,  6  and  7 , support system  160  is provided for securing enclosure  100  in selected vertical relationship with tank  30 , such as that illustrated in FIG.  2 . Support system  160  includes straps  162  and  164  which are secured together by buckle  166 . Preferably, buckle  166  both permits straps  162  and  164  to be drawn toward one another and secures the straps relative to one another in selected relation. Alternatively, a single strap (not shown) having a length equal to that of straps  162  and  164  may be used in place of the two straps. In such case, buckle  166  is not required. Also, straps  162  and  164  may be individually secured to tank housing  38  with a hook and buckle or similar cinching mechanism. When enclosure system  20  will be used in an environment where a substantial load, i.e., from snow, will be applied to lid  200 , it may be desirable to use two support systems  160 , positioned in mutually perpendicular relation. 
     Support system  160  also includes hooks  170  and  172  which are secured, respectively, to the ends of straps  162  and  164 . Hooks  170  and  172  have a U-shaped configuration sized so as to receive portions of staves  102   b  (see FIG. 7) adjacent bottom edge  116 . As described in more detail below, straps  162  and  164  are sized so that when secured together by buckle  166  they extend from a first location on bottom edge  116 , up over the top of tank  30  and down to a second location on bottom edge  116  that is positioned approximately opposite, i.e., 180° away from, the first location. 
     Turning now to FIGS. 1,  2  and  8 , enclosure system  20  preferably, but not necessarily, includes lid  200 . The latter is sized to sit on top of enclosure  100 , engaging top surface  114 . If desired, lid  200  may include a flexible flange  202  at the periphery of the lid for compressively engaging portions of staves  102  adjacent top edge  114  of enclosure  100 . Lid  200  may be made from a variety of materials including wood, metal, plastic and composites. 
     Referring to FIG. 9, in some circumstances, e.g., when enclosure system  20  is used in a hot climate, it may be desirable to provide ventilation in the lid of the system. To this end, an alternative embodiment of the lid, identified by reference numeral  300  in FIG. 9, is provided. Lid  300  is identical to lid  200 , except that it has a central opening  302  which is covered by cap  304  supported above opening  302  by legs  306 . Preferably, legs  306  are sized so that the peripheral edge of cap  304  is spaced about 1″ above adjacent portions of lid  300 . Also, cap  304  is preferably sized to overhang opening  302  by about 1″. 
     Installation of the preferred embodiment of enclosure system  20 , illustrated in FIGS. 1-9, proceeds as follows. This description assumes enclosure  100  is assembled to the degree illustrated in FIG. 3, and is in the substantially planar position illustrated in FIG.  3 . Enclosure  100  is moved adjacent tank  30  so that staves  102  are in a substantially vertical position and top end  114  is positioned on top. Next, enclosure  100  is wrapped around tank  30 . The flexible nature of bands  112  permits the discrete staves  102  to move relative to one another sufficiently to permit such wrapping. In some cases, it may be necessary to remove the top portion of one or more staves  102   a  to accommodate a gas supply line (not shown) leading away from tank  30 . 
     Flat portion  136  of rack portion  132  of clamp  130  is then inserted into housing  140  of pinion portion  134  of clamp  130  so that the teeth (not shown) in the housing engage slots  138 , and screw head  142  is turned so as to draw the flat portion into the housing. As this turning action continues, staves  102 ′ and  102 ″ are drawn toward one another, causing enclosure  100  to compressively engage tank  30 . Spacers  120  provide the point of contact between enclosure  100  and tank  30 . Before clamps  130  are tightened sufficiently to prevent enclosure  100  from moving vertically relative to tank  30 , the enclosure is vertically positioned as desired, preferably so that bottom end  116  of the enclosure is positioned about 4-6 inches above surface  50 . In this position, vents  110  are positioned in substantial vertical alignment just above the bottom of shoulder  36  of tank  30 . Finally, lid  200  or  300  is positioned on top end  114  of enclosure  100 . 
     Under some circumstances the compressive engagement of enclosure  100  with tank  30  created by clamps  130  is sufficient to retain the enclosure in the above-described position relative to the tank. However, to ensure enclosure  100  remains in this position, one of the above-described support systems, such as support system  160 , may be employed. Support system  160  is partially installed before enclosure  100  is secured to tank  30 . In this regard, what will become the buckled end of strap  164  is inserted through diametrically opposed openings  42  at the base of housing  38 , avoiding all valves and gauges as necessary (see FIG.  6 ), and the remainder of strap  164 , with hook  172  secured to its lower end, is draped over the outer surface  33  of tank  30  and adjusted until hook  172  is just resting on surface  50 . Strap  164  is then temporarily secured in this position to the outer surface  33  of tank  30  using tape or other suitable materials. Next, strap  162 , with hook  170  secured to its lower end, is draped over outer surface  33  of tank  30  in substantially diametrically opposed relation to strap  164  and is adjusted until hook  170  is just resting on surface  50 . Strap  162  is also temporarily secured in this position with tape or other suitable materials. 
     Following installation of enclosure  100  on tank  30  as described above, hooks  170  and  172  are positioned to engage bottom end  116  of the enclosure, preferably on diametrically opposed ventless staves  102   b  and to one side of each of the staves (see FIG. 7) to allow attached straps  162  and  164  to avoid spacers  120  attached to said staves. Straps  162  and  164  are then adjusted relative to one another so that hooks  170  and  172  pull upwardly against bottom edge  116  with moderate force. This adjustment is achieved via buckle  166  or similar cinching mechanism. Tape or other materials for temporarily securing straps  162  and  164  to tank  30  may be removed if desired. Following this procedure, enclosure  100  is then installed around tank  30  in the manner described above. 
     As noted above, when lid  200  or  300  will be subjected to a heavy load, two support systems  160  may be needed. Each of the support systems  160  is installed in the manner described above, with the systems being positioned in mutually perpendicular relation. 
     The total area of vents  110  and the circumferential opening between bottom end  116  of enclosure  100  and surface  50 , described above, i.e., about 1 square inch for each pound of gas stored in tank  30 , is selected based on the assumption bottom end  116  of enclosure  100  will be positioned about 4-6 inches above surface  50 . With such positioning, about 0.1 to 0.5 of the total desired vent area for enclosure  100  is provided via vents  110 . As illustrated in FIGS. 1-3 and  8 , only about 0.1 of the total desired vent area is provided by vents  110 . The circumferential opening below enclosure  100  is designed to prevent gases that escape from tank  30  and enclosure  100  from accumulating at the base of the enclosure. 
     When enclosure system  20  is used to enclose tanks or other objects that do not potentially emit gases requiring ventilation, vents  110  are not required and it is not necessary from a ventilation standpoint that enclosure  100  be positioned above surface  50 . However, if the tank or other object is subject to rot or corrosion as a result of the presence of moisture within enclosure system  20 , it may still be desirable to use vents  110  and/or position enclosure  100  above surface  50 . 
     An important advantage of enclosure system  20  when installed relative to tank  30  in the manner described above is that the enclosure system substantially visually blocks the tank. This permits a tank  30  to be installed in certain environments where it could not otherwise be used due to the relatively unattractive nature of such tanks. Even where aesthetic concerns would not block installation of tank  30 , enclosure system  20  provides a more visually satisfying appearance for the tank. The small portions of tank  30  that may be visible through enclosure  100 , e.g., via vents  110  or opening  124 , do not detract to any meaningful extent from the overall aesthetic benefit provided by the present invention. 
     Since certain changes may be made in the enclosure system described above without departing from the present invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted in an illustrative and not in a limiting sense.