Abstract:
A method of providing a textured surface to the floor of a refrigerated storage enclosure. The steps include applying a layer of resinous material over the surface of the floor, the surface being formed of a hardened material, placing a single layer of sand on the layer of resinous material, and applying a layer of clear epoxy resin over the layer of sand. The layer of sand is evenly applied, and the layer of clear epoxy resin applied over the layer of sand is permitted to harden.

Description:
This application is a divisional Application Ser. No. 09/212,387, filed on Dec. 16, 1998, U.S. Pat. No. 6,190,490 the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to insulated storage enclosures and more particularly to a method of making a monolithic storage enclosure out of assembled side, ceiling and base members cut from a single slab of polyurethane coated with a layer of fiberglass reinforced resinous material and the method of making a closure member therefor. 
     Heretofore, monolithic insulated storage enclosures of the type set forth in our U.S. Pat. No. 4,925,509 were constructed by securing a skid to a base of polyurethane by a layer of fiberglass reinforced resinous material and positioning the sides and ceiling members on the base to form the enclosure. A coating layer of fiberglass reinforced resinous material was then applied over the inside and outside surfaces of the erected base, side and ceiling members to secure the members to each other to form the enclosure. Application of the coating layer to the inside surfaces of the erected base, side and ceiling members was both difficult due to the limited space available to maneuver spraying equipment, etc., which increased as the overall size of the enclosure decreased, and to the health hazards associated with the equipment operator&#39;s difficulties with breathing in a confined space considering the nature of the relatively toxic resinous material which is applied to the surfaces in spray form. The method of constructing the closure member is also disclosed. 
     The method of the present invention overcomes the aforementioned difficulties of constructing enclosures of polyurethane coated on all surfaces with a layer of fiberglass reinforced resinous material by forming the base, side and ceiling members as part of a long horizontally-positioned continuous slab of polyurethane. The entrance and other desired openings are formed in the slab, the slab is coated on one side with a layer of fiberglass reinforced resinous material and the slab is then cut into sections representing the base, side and ceiling members. The side and ceiling members are arranged on the base with the precoated surface of each facing the inside of the formed enclosure. Thus, to essentially complete the enclosure, all that need be done is to apply another coating of the resinous material to the outside surfaces of the side and ceiling members. The present invention also includes the method of constructing the closure member for the enclosure. 
     It is, therefore, the primary object of the present invention to provide a superior method of constructing storage enclosures of the type made of polyurethane covered with a layer of fiberglass reinforced resinous material. 
     It is another object of the present invention to provide a method of constructing storage enclosures of the subject type wherein all of the inside surfaces are precoated, thus substantially eliminating the necessity of applying coating material while inside the enclosure. 
     It is a further object of the present invention to provide a method of constructing storage enclosures of the subject type wherein door jambs and the like are secured in place by the coating material. 
     It is a still further object of the present invention to provide a method of constructing a closure member for the enclosure. 
     It is yet another object of the present invention to provide a method of constructing storage enclosures of the subject type which result in cost savings due to greater labor efficiency, reduced material waste and healthier working environments. 
     These and other objects and advantages will become apparent to those skilled in the art when the foregoing is considered in conjunction with the following brief description of the drawings and detailed 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an oblique view of an enclosure constructed according to the method set forth in this invention; 
     FIG. 2 is an oblique view of the elongated slab from which the side and ceiling members of the enclosure are formed; 
     FIG. 3 is an oblique view of the slab with recesses formed therein; 
     FIG. 4 is an oblique view of the slab being covered with a layer of resinous material and cut into sections to form the side and ceiling members; 
     FIG. 5 is an oblique view of the erected base, side and ceiling members with parts broken away; 
     FIG. 6 is an oblique view showing the skid being attached to the base by coating material; 
     FIG. 7 is an enlarged fragmenting view in cross-section taken along the likes  7 — 7  of FIG. 6; 
     FIG. 8 is a perspective view in partial cutaway of the closure member or door constructed by the method of the present invention depicted in the mold in which it was constructed; 
     FIG. 9 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the first step of the method for forming the closure member; 
     FIG. 10 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the second step of the method for forming the closure member; 
     FIG. 11 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the third step of the method for forming the closure member; 
     FIG. 12 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the fourth step of the method for forming the closure member; 
     FIG. 13 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the fifth step of the method for forming the closure member; 
     FIG. 14 is a cross-sectional view taken along lines  10 — 10  of FIG. 8 showing the sixth step of the method for forming the closure member; 
     FIG. 15 is a partial view in cross-section showing an alternative construction employing the six method steps for forming the closure member; 
     FIG. 16 is a cross-section view of the closure member or door taken along the lines  16 — 16  of FIG. 8; and 
     FIG. 17 is a partial cross-section view of another embodiment of the closure member. 
    
    
     DETAILED DESCRIPTION OF INVENTION 
     Referring now to the drawings where like characters of reference indicate like elements in each of the several views, numeral  10  shows generally the frameless, insulated storage enclosure constructed by the method of the present invention. The enclosure comprises the principal elements of a substantially rectangular box-shaped, monolithic shell  12  mounted on a transport skid  14 . The shell  12  also has a freezer-type insulated closure or door  16  mounted thereon. 
     The shell  12  is constructed by the method steps depicted in FIGS. 2-5 and comprises an elongated slab of low density, foamed synthetic resin material such as polyurethane about 4 inches in thickness, as shown in FIG.  1 . The slab  18  is typically placed on a horizontal forming pallet  20  resting on the floor. When side panels are being formed, the width dimension (a) would be substantially the interior height of the enclosure and where the base and roof panels are being made, the dimension (a) would be substantially the exterior width of the enclosure. Next door, window and other openings  22  are cut into the slab  18  which represent desired passageways through the panels of the finished enclosure. A door jamb  24 , typically made of wood, would then be positioned in the opening  22 , as shown in FIG.  2 . Frames (not shown) for other openings  22  would also be inserted at this time. A continuous layer  26  of polyester resin reinforced with a fibrous material such as filamentary glass in which the filaments are arranged in the resinous material at random is applied approximately ⅛ inch thick to the slab  18 . Typically, the fiberglass reinforced resinous material  26  is applied in spray form with what is commonly referred to as a hand-held “chopper gun”  28  and smoothed into a continuous layer of uniform thickness by a T-shaped implement  30 . The gun  28  chops fiberglass in the form of twine into short lengths, mixes it in the resin, and blows it against the slab  18 . The layer of material  26  is applied over the entire exposed surface of the slab  18  as it rests on the pallet  20  including the door jamb  24  and other frame elements thereby securing them in place, as shown in FIG.  4 . The layer of resinous material  26  is then permitted to cure or harden. After the layer  26  has cured, the slab  18  is cut as shown at  32  by a power saw or the like into panels  34 ,  36 ,  38  and  40  forming the sides of the enclosure  10  or to separate the base panel  42  from the roof panel  44 . To complete the enclosure  10 , the side panels  34 ,  36 ,  38  and  40  are erected on the base panel  42 , as shown in FIG. 5, and the roof panel  44  is placed on top such that the side of the panels containing the layer of material  26  is faced inwardly. 
     After the erection of the side, base and roof panels to form the enclosure  10 , the outside surface of the panels is covered with a layer of resinous material  26  by means of the chopper gun  28  to thereby form a continuous surface including all abutting joints  46 . To complete this part of the enclosure  10 , a transport skid  14  may be attached to the bottom  48  of the base  42  by the means disclosed in my aforementioned U. S. patent and shown in FIGS. 6 and 7. The bottom surface  48  is first covered with a layer of resinous material  26  and allowed to cure. The skid  14  is then positioned on the cured layer and secured thereto by means of the same resinous material  26  shown surrounding the I-beam member  50 . Attachment of the skid  14  to the base  42  in this manner eliminates the necessity of fasteners which could penetrate the covering layer of resinous material  26  permitting moisture, etc. to enter. 
     Referring now to FIG. 8, the closure member or door  16  for the enclosure  10  is shown positioned in the shallow, rectangular-shaped mold  52  having a cavity  54 . The closure member  50  has a raised central portion  56  containing polyurethane insulation  57  and a peripheral lip portion  58  around the central portion and having a channel  60  embedded therein for retaining a door seal  62 . The mold  52  is essentially a rectangular-shaped five-sided enclosure having a peripheral wall  64  and a bottom  66  having a highly polished surface  67  to ensure quick release and the impartation of a highly smooth blemish-free outside surface for the closure member  16 . 
     To construct the closure member  16 , FIGS. 9-14 depict the method steps involved. More specifically, in FIG. 9, the mold  52  is shown having the aforementioned highly polished surface  67 . On this surface  67  is placed at least one layer  68  of fiberglass, reinforced resinous material, extending to the side walls  64  of the mold  52 . Preferably, three layers of the material  68  are placed on this polished surface  67  but only one is shown here in the interests of clarity. Next, as shown in FIG. 10, a core  57  of polyurethane insulation, preferably of at least three inches in thickness, is placed on the aforementioned still wet fiberglass  68  and equi-spaced a distance from the walls  64  to thereby form a border  70  around the core  57 . Next, as shown in FIG. 11, at least one border layer  72  is placed on the still wet fiberglass  68  extending from the wall  64  and up a distance on the side  74  of the core  57 . Preferably, three border layers  72  are laid on the still wet fiberglass bottom layer  68 . As an alternative, a strip of wood (not shown) can be substituted for the two border layers  72  closest to the bottom layer  68 . Next, as shown in FIG. 12, at least one cover layer  74  is placed on the still wet border layer  72  and the entire outer surface  76  of the core  57 . Preferably, two cover layers  74  are laid on the still wet border layer  72  and core  57 . Next, as shown in FIG. 13, a substantially longitudinally extending U-shaped channel  76  of plastic material is placed on the still wet border layer  72  intermediate the wall  64  and the core  57  around the entire border layer  72 . Finally, as seen in FIG. 14, a quantity of resinous material  78  such as gel-coat is applied around the channel  76  to secure it to the border layer  72 , and all layers are permitted to set up until hard. Also, a length of flexible sealing strip  62  is inserted into channel  76  to complete the closure member  50 . The sealing strip  62  can be provided with a longitudinally extending pocket  82  for receiving a strip of magnetized, flexible material  84  for sealing the door periphery when the strip  62  is brought in contact with a metal border around the door opening  22  (not shown). 
     Referring now to FIG. 15, there is shown a partial view of a door  16  comprising the preferred construction if a more substantial or heavier door is desired, which consists of three layers  68  of fiberglass, reinforced resinous material, followed by three border layers  72  of similar material and then followed by two cover layers  74 ; or, as an alternative, a top border layer  72  and a strip of wood (not shown) can be substituted for two of the border layers  72 . 
     FIG. 16 shows a core  57  having three rectangular-shaped channels  86  cut in the face  88  thereof. Lengths of wood  90  are secured in the channels  86  before the core  57  is placed on the initial layer(s)  68  to provide a means to anchor screws for door hinges and lock hardware (not shown). 
     FIG. 17 is a variation of the present invention of FIG. 9 wherein a thin layer of gelcoat  69  is first placed on the mold cavity surface  67  and permitted to set up. This gelcoat layer  69  serves to both impact the smooth surface  67  to the front of the closure member  16  as well as fill in any minor voids present in the first layer of fiberglass  68  which is then laid thereon. Various colors can be added to the gelcoat layer  69  if desired. 
     In order to provide a textured surface  92  to the inside floor formed by the base  42 , an additional layer of resinous material  94  can be applied to the hardened layer  26 , as shown in FIG. 5. A layer of sand  96  is then applied evenly over the additional layer  94 . The sand  96  can be a mixture of equal parts of light and dark sand for a varied appearance; and, finally, a cover layer  98  of clear epoxy resin is applied over the sand layer  96  and permitted to harden, thus resulting in a mildly rough, slip resistant surface even when wet.