Abstract:
A multi-piece lightweight pre-formed equipment base wherein each piece, i.e., the outer shell of the pad and the support ribbing, may be constructed from materials having the desired properties for that piece&#39;s function, and wherein each piece is capable of nesting with like pieces.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates generally to a base for equipment, and in particular to a lightweight, pre-formed base for equipment.  
         [0002]     It is well known in the art that industrial equipment such as air conditioning condensers, heating units, and electrical transformers should be elevated above the ground in order to protect the equipment from damage caused by vibration or contaminants, e.g., dirt, debris, and moisture. Historically, such equipment was mounted on bases constructed from concrete. Concrete equipment bases proved unsatisfactory because pouring and smoothing the concrete bases at the construction site was very time-consuming and costly, and pre-cast concrete bases were generally too heavy to manipulate or ship economically.  
         [0003]     The dissatisfaction with concrete equipment bases gave rise to the use of pre-cast equipment bases made from composite materials. For instance, U.S. Pat. No. 4,505,449 suggests a composite pad having a polystyrene foam core covered on five sides with a fiberglass and cement composition. Such a composite pad is preferred over a concrete base because it maintains the preferred monolithic appearance of a concrete base, but weighs less than a concrete base and is capable of supporting the same or greater loads than a concrete base. Additionally, pre-cast composite bases, because of their lighter weight, can be installed without heavy equipment and transported with greater ease.  
         [0004]     Recent improvements in the art have been aimed at manipulating either the material used for the core of the equipment base or the material used for the outer pad of the base. For example, U.S. Pat. No. 6,050,539 proposes the use of a moldable lightweight plastic material for the core component, rather than polystyrene foam, but continues to surround the core with a concrete shell. Alternatively, U.S. Pat. No. 4,869,456 suggests retaining the cellular foam core, but constructing the pad out of molded plastic and interspersing the interior of the pad with plastic strengthening ribs. Although both these methods serve to produce a lightweight equipment base, their relative bulk makes them costly to ship. These products typically consume the cube of a shipping vessel (truck or container) well before they reach the weight limit of that shipping vessel.  
         [0005]     To alleviate the costs of transportation, equipment bases capable of being stacked one upon another have been used, thereby minimizing the volume needed for shipping. U.S. Pat. No. 5,895,025, in particular, discloses an equipment base that may be stacked in pairs—the irregular bottom surface of one base nesting within the irregular bottom surface of a second base.  
         [0006]     Another problem with conventional molded plastic equipment bases is that the outer shell of the pad and the support ribs are molded out of the same material, despite the fact that the properties desirable for the outer shell are not often the same as those required for the support ribs. The outer shell, including the top surface and four sides of the equipment base, is subject to and must be resistant to ultraviolet (UV) radiation, moisture, organisms, impacts, and many common chemicals. The support ribs are free from such exposure, but must be of adequate strength and stiffness to support the heavy loads applied to the top surface of the base.  
         [0007]     A need therefore exists for an improved pre-formed equipment base that has the necessary strength to support heavy loads, yet is lightweight, inexpensive to manufacture, aesthetically appealing, easy to transport, simple to install, and takes into account the difference in desired properties between the outer shell and support ribbing.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention answers this need by providing a multi-piece lightweight pre-formed equipment base wherein each piece, i.e., the outer shell of the pad and the support ribbing, may be constructed from materials having the desired properties for that piece&#39;s function, and wherein each piece is capable of nesting with like pieces so that shipping limits on weight and volume are reached simultaneously.  
         [0009]     Generally described, the present invention relates to a base for equipment, including a pad having a top surface, a plurality of side surfaces, and a hollow core. At least one insert support ribbing mates with the hollow core to construct the base. Furthermore, the hollow core of the pad is adapted to receive the top surface of a similarly-formed second pad such that multiple pads may be stacked one upon another to minimize shipping volume. Likewise, the at least one insert support ribbing is adapted to receive a similarly-formed second at least one insert support ribbing such that multiple support ribbings may be stacked one upon another to minimize shipping volume.  
         [0010]     It is thus an object of the present invention to provide an equipment base that allows the outer shell of the pad and the support ribbing to each be constructed out of materials selected for their performance attributes, i.e., materials having the desired properties for the function of that particular part of the equipment base.  
         [0011]     It is a further object of the present invention to provide an equipment base that may be condensed for shipment, thereby reducing transportation costs.  
         [0012]     In an embodiment of the present invention, the outer shell of the pad is molded in one piece, having a top surface, four sides, and a hollow core, constructed out of plastic or a composite material. In such embodiments, it is an object to provide an aesthetically desirable monolithic-looking equipment base. Because the outer shell of the pad is molded separately from the ribbing, it is another object to provide a base that is inexpensive to manufacture.  
         [0013]     In an embodiment of the present invention, the second core piece of the base, the support ribbing, is constructed from a plastic material or other conventional materials. The support ribbing mates with the hollow core of the pad via a snap fit, adhesives, fasteners, or other conventional means. In such embodiments, it is an object to provide an equipment base that may be easily assembled as close to the end use point as possible. Because the support ribbing is separately molded, it is a further object to provide an equipment base that maximizes ground contact and strength, while minimizing material.  
         [0014]     Other objects, features, and advantages of the present invention will become apparent upon inspection of the following detailed description of the preferred embodiment of the invention, taken in conjunction with the drawings and appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a top perspective view showing the joinder of the pad and the insert support ribbing in an embodiment of the present invention.  
         [0016]      FIG. 2  is a bottom perspective view showing the insert support ribbing mated with the hollow core in an embodiment of the present invention.  
         [0017]      FIG. 3  is a side view of multiple pads nested for compact shipment in an embodiment of the present invention.  
         [0018]      FIG. 4  is a side view of multiple insert support ribbings nested for compact shipment in an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring to  FIGS. 1 and 2 , the present invention provides a multi-piece lightweight pre-formed equipment base  10 . The equipment base  10  includes a pad  20  and an insert support ribbing  30 . The pad  20  has a top surface  22 , a bottom surface  24 , and four downwardly extending side surfaces  26 , creating a hollow core  28 . The periphery of the pad  20  forms an edge  25  to provide structural support for the pad  20 . The pad  20  is a unitary structure, preferably constructed from molded or thermoformed plastic such as polypropylene, polyethylene, acrylonitrile butadiene styrene (ABS), polystyrene, polyvinyl chloride (PVC), or high impact polystyrene (HIPS) using an A-B injection mold tool. In alternative embodiments steel, aluminum, wood, metals and other non-plastic materials and plastic/non-plastic composites may also be injection molded. Those of ordinary skill in the art will appreciate that the invention encompasses virtually any material and composites capable of injection molding depending on the desired characteristics of the formed article.  
         [0020]     A typical pad  20  manufactured according to this embodiment is square in shape, two (2) to three (3) inches in height, and available in various sizes, including, in exemplary embodiments, 24×24 inches and 60×60 inches. In other embodiments the pad may be rectangular, such as one embodiment provided for a 48×96 inches pad. It will be appreciated that all dimensions will vary according to the end-use and desired characteristics of the pad.  
         [0021]     The top surface  22  and the side surfaces  26  of the pad  20  are generally continuous with no recesses or holes therein because of building codes requirements and aesthetic preferences of contractors and owners. To permit nesting, the side surfaces  26  will not be normal to the top surface  22 , but rather will differ from ninety-degrees by the draft angles present in the utilized molds. A pad  20  constructed according to these dimensions and constructed out of either polypropylene or polyethylene can support approximately 300 to 1000 pounds of load on typical soil.  
         [0022]     The insert support ribbing  30  includes a top surface  32 , a bottom surface  34 , and a plurality of upwardly extending ribs  36 , creating a hollow core  37 . The insert support ribbing  30  is a unitary structure, preferably constructed using an A-B injection mold tool. The support ribbing may also be formed of virtually any materials and composites as the pad  20 . However, unlike the pad  20 , the material of the support ribbing  30  does not typically have any aesthetic requirements, so less expensive materials that provide sufficient sturdiness for support functions can be used.  
         [0023]      FIGS. 1 and 2  depict an exemplary arrangement of features  40  forming such ribs  36 , designed principally to maximize ground contact and strength while minimizing material. Such an arrangement also acts to inhibit lateral and rotational movement of the equipment base  10  relative to the ground. In the embodiment of the invention shown, the insert support ribbing  30  includes five (5) octangular features  40  arranged in a star-like pattern, having a central feature  42  and four peripheral features  44  radiating from the central feature  42  toward the corners of the insert support ribbing  30 , and connected to the central feature  42  by rectangular support ribs  46 . Four (4) additional linear support ribs  46  radiate from the central feature  42  at ninety-degree angles toward the sides of the insert support ribbing  30 .  
         [0024]     In one embodiment, the bottom surface  34  of the features  40  contains a series of rectangular and circular holes  38 . In such an embodiment, the holes  38  tend to collect soil, thereby locking the equipment base  10  into position and preventing lateral and rotational movement of the base  10  after equipment has been mounted. In addition, constructing the bottom surface  34  of the features  40  with such holes  38  minimizes the material necessary for manufacture of the insert support ribbing  30 , thus reducing the overall weight and manufacturing costs of the equipment base  10 .  
         [0025]     The joinder of the insert support ribbing  30  with the pad  20  is shown in  FIG. 1 . The insert support ribbing  30  is sized to snap fit into the edge  25  of the pad  20  and fill the hollow core  28 .  FIG. 2  shows the insert support ribbing  30  mated with the pad  20 .  
         [0026]     Although embodiments of the equipment base  10  consistent with  FIGS. 1 and 2  are particularly useful in maximizing ground contact and strength while minimizing material, and tend to inhibit lateral and rotational movement of the equipment base  10 , other arrangements may be adequate to achieve the desired results. For example, while the features  40  of the insert support ribbing  30  are shown to be octangular and arranged in a star-like pattern, they need not be so shaped or arranged. Similarly, although the insert support ribbing  30  described is a unitary structure, other embodiments of the present invention consist of more than one insert support ribbing  30 . Also, other methods of joinder for the pad  20  and the insert support ribbing  30  may be used, including adhesives, mechanical fasteners, welding, Emabond, stapling, hot staking or other conventional means. Finally, there is no requirement that the equipment pad  20  be square. Any conventional shape may be employed, including, but not limited to, round, octagonal, rectangular, and the like.  
         [0027]     As shown in  FIG. 3 , multiple pads  20  may be stacked one upon another by nesting the top surface  22  of one pad  20  within the hollow core  28  of a second, similarly formed pad  20 ′. The top surface  22  of the first pad  20  thus becomes near to flush with the bottom surface  24  of the second pad  20 ′, thereby reducing shipping volume.  
         [0028]     Likewise,  FIG. 4  shows that multiple insert support ribbings  30  may be stacked one upon another by nesting the bottom surface  34  of one insert support ribbing  30  within the hollow core  37  of a second, similarly formed insert support ribbing  30 ′. The bottom surface  34  of the first insert support ribbing  30  thus becomes near to flush with the top surface  32  of the second insert support ribbing  30 ′, thereby reducing shipping volume.  
         [0029]     Similarly, the pads  20  and the insert support ribbings  30  may be stacked while awaiting use. In use, the respective components of the equipment base  10 , the pad  20  and the insert support ribbing  30 , can be shipped separately. The insert support ribbing  30  can be joined with the pad  20  as close to the end use point as preferred to assemble the equipment base  10 . Installation of the equipment base  10  at the construction site or other location requires little site preparation beyond having an essentially flat region. The equipment may then be secured to the base  10 . After use, the insert support ribbing  30  can be disjoined from the pad  20  and both can be reused.  
         [0030]     Although this invention has been described in specific detail with reference to the disclosed embodiments, it will be understood that many variations and modifications may be affected within the spirit and scope of the invention as described in the following claims.