Abstract:
A device or apparatus that receives and supports a pipe, especially a pipe exposed on a horizontal surface like a roof. The device has a base with a substantially flat bottom for resting on the horizontal surface and a supporting structure with a recess rising from the base to support the pipe. Positioning means are provided in the bottom of the recess to position and center the pipe within the recess. Such a device maximizes the sliding ability of the pipe and minimize erosion of the recess since the pipe rarely abuts the walls of the recess.

Description:
FIELD OF THE INVENTION 
     The present invention relates to devices for supporting pipes. In particular, the present invention relates to devices for supporting pipes on horizontal surfaces, such as exterior pipes on roofs. 
     BACKGROUND OF THE INVENTION 
     Pipes often run along the roofs in buildings, including commercial buildings, for various purposes such as connecting air conditioning units or other service units that are mounted on the roof. These pipes are often supported above the horizontal surface at intervals along their length by placing supporting mechanisms, like blocks of wood between the horizontal surface and the pipes. When the temperature changes, the pipes expand and contract and often the wood block moves with pipe because, in part, of the large contact surface area between the block and the pipe. Eventually, movement of the block against the roof combined with the weight of the pipe on the wood block causes damage to the roof, resulting in leaks and requiring expensive roof repair. Even if the wood blocks are nailed to the roof, the nails and the wood can deteriorate and the blocks can break loose. 
     Various types of pipe supporting mechanisms are known in the art. See, for example, U.S. Pat. Nos. 5,906,341, 5,871,306, 5,102,073, 5,028,019, 5,028,149, 5,685,608, 4,502,653, 4,513,934, and 5,829,718, the disclosures of which are incorporated herein by reference. Some of these pipe-supporting mechanisms have a substantially flat-bottomed base and a pipe supporting structure rising from the base that distributes the weight of the pipe over the bottom of the base and thus over the area of the roof in contact with the base. This pipe supporting structure has a recess above the base for receiving and supporting the pipe. A small roller is provided in a trough in the bottom of the recess to facilitate the sliding movement of the pipe. 
     There are several problems, however, with the types of prior art devices having a small roller in the trough. The small roller is not affixed in the trough and can fall out during shipping or installation of the product. Further, the small roller does not center the pipe within the recess, allowing the pipe to abut the sides of the recess. When the pipe abuts the recess, the ability of the supporting mechanism to facilitate the sliding movement of the pipe is reduced and deterioration of the recess wall (and the pipe) is increased. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a device or apparatus that receives and supports a pipe, especially a pipe exposed on a horizontal surface like a roof. The device has a base with a substantially flat bottom for resting on the horizontal surface and a supporting structure with a recess rising from the base to support the pipe. Positioning means are provided in the bottom of the recess to position and center the pipe within the recess. Such a device maximizes the sliding ability of the pipe and minimizes erosion of the recess since the pipe rarely abuts the walls of the recess. 
     The present invention includes a device for supporting a pipe, the device having a base, a structural member extending upward from the base, the structural member having a recess for receiving the pipe, and pipe positioning means located in a lower portion of the recess. The base may have a substantially flat bottom, such as a bottom with about 80% to about 90% of surface of the bottom comprising a flat area. A portion of the recess may have a u shape or a curvilinear shape so that the pipe will not abut the walls of the recess when placed on the positioning means. The pipe positioning means may be a cylindrical shaft with a sleeve positioned thereon. The device may contain means for restraining the shaft relative to the structural member. The sleeve may be configured to position the pipe away from the side walls by substantially centering the pipe between the side walls. The sleeve may have an outer surface with the diameter of the sleeve at the end portions being larger than the diameter of the sleeve at the middle portion. The smaller diameter in the middle portion may taper to the larger diameter at the end portions and the incline of the taper may substantially match the outer surface of the pipe resting on the sleeve. The restricting means may comprise a collar and a friction bar located in the structural member proximate the ends of the shaft. 
     The present invention also includes a device for supporting a pipe containing a base, a structural member extending upward from the base with the structural member having a recess for receiving the pipe, pipe positioning means located in a lower portion of the recess, and means for restricting the location of the pipe positioning means relative to the structural member. 
     The present invention further includes a method for supporting a pipe by first providing a pipe, then providing a device having a base and a structural member extending upward from the base with the structural member having a recess, the device also having positioning means located in a lower portion of the recess, and then placing the pipe within the recess and on the positioning means. The device may be provided with means for restricting the location and size of the pipe positioning means relative to the structural member. 
    
    
     DRAWINGS 
     FIGS. 1-6 presented in conjunction with this description are views of only particular—rather than complete—portions of the structural member and method of making the same. 
     FIG. 1 illustrates a portion of a building roof with an exposed pipe supported by a device of the present invention. 
     FIG. 2 illustrates a front view of a pipe-supporting device of the present invention. 
     FIG. 3 illustrates a top view of a pipe-supporting device of the present invention. 
     FIG. 4 illustrates a bottom view of a pipe-supporting device of the present invention. 
     FIG. 5 illustrates a front view of pipe being supported by a pipe supporting device of the present invention. 
     FIG. 6 illustrates a top view of pipe being supported by a pipe supporting device of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description provides specific details in order to provide a thorough understanding of the present invention, but the present invention can be practiced without employing these specific details. Indeed, the present invention can be practiced by modifying the illustrated device and can be used in conjunction with apparatus and techniques conventionally used in the industry. Indeed, the present invention could be employed in other applications, such as supporting pipes on any substantially horizontal surface, not merely on a roof. 
     It is common in buildings to have pipes supported above the roof. FIG. 1 shows a common installation for pipe  10  which extends from a service unit  12  (such as an air conditioning unit) across the roof  14  to a location (not shown) over the side of the roof, through the roof, or is connected to other roof-mounted equipment such as other service units. At least one pipe supporting device  16  of the present invention is placed on the roof to cradle and support pipe  10  as it extends along the roof. 
     The number of pipe supporting devices  16  needed to properly support the pipe depend on several factors. Such factors include the type of pipe used, the size of the pipe, the weight of the pipe, the material of the pipe, the configuration of the pipe on the roof, as well as the material and configuration of the pipe-supporting devices. 
     FIGS. 2-6 illustrate several configurations of pipe-supporting device  16 . As shown in FIG. 2, each pipe-supporting device  16  includes a base  18  with support structure  20 . The height of pipe-supporting devices  16  generally ranges from about 2 inches to about 4 inches. Preferably, the height of pipe-supporting devices  16  is about 4 inches. The pipe-supporting devices  16  can be stacked on one another via stacking pins  19  to support pipes at different heights. The pipe-supporting device can also be placed side-by-side to support multiple pipes. 
     Base  18  of pipe-supporting device  16  can be of any suitable configuration known in the art. Suitable configurations include those which evenly distribute the weight of the pipe such as round, triangular, rectangular, square, hexagonal, octagonal, etc . . . As known in the art, base  18  can optionally serve as a pitch pan for holding pitch that is poured therein to act as a sealant for nails or screws that are used to connect base  18  to roof  14 . 
     The size of base  18  can be any size providing the needed structural integrity for device  16 . The dimension of base  18  can range (for example, when the base is substantially square) from about 6 inches by about 6 inches to about 7½ by 7½ inches. Preferably, base  18  has a substantially square base with dimensions about 7½ by 7½ inches. 
     The pipe-supporting device  16  of the present invention provides substantially even distribution of the pipe weight over base  18 . The bottom of base  18 , therefore, should be configured in any desired manner to maximize support for the pipe-supporting apparatus. Thus, at least one portion of the bottom of base  18  has a substantially flat bottom. Further, the bottom of base  18  has a substantially flat peripheral area contacting the roof surface. Preferably, the bottom of base  18  should be configured to provide maximum surface area between base  18  and roof  14 . For example, about 75% to about 80% of the bottom of base  18  could be configured to contact roof  14 . 
     One preferred example for maximizing this surface area is illustrated in FIG.  4 . As seen in FIG. 4, the flat area  17  of base  18  contacting the horizontal surface is maximized in all areas except for empty areas  19  under support structure  20  which are present because of limitations during the molding process used to make device  16 . The substantially flat area  17  is maximized, thereby minimizing the pipe weight per unit area of base  18 , e.g., to a value at least less than the breaking point or tensile strength of the roof or horizontal surface, for example, less than about 5 lbs/in 2 . If desired, the bottom of base  18  can be formed so that channels and drain holes are provided therein, as described in U.S. Pat. No. 4,502,653, the disclosure of which is incorporated herein by reference. 
     The corners of base  18  are substantially rounded and may be turned up so that they will not gouge the roof surface if supporting device  16  slides along the roof. The edges of base  18  can also be substantially rounded and raised from the horizontal surface on which they are placed to avoid gouging that surface. The height the corners and edges are raised ranges from about ½ inch to about 2 inches. Preferably, the edges of the base  18  are raised about ½ inches from the horizontal surface. 
     Support structure  20  extends from base  18  and cradles pipe  10 . Support structure  20  can have any suitable configuration providing the necessary structural integrity, including those known in the art. Suitable configurations include any of those which connect with base  18  at the bottom and provide an upper surface for cradling the pipe. Preferably, support structure  20  is substantially square where it joins base  18  and provides a recess (or pocket)  22  at the top for receiving the pipe to be supported. Supporting structure  20  can be formed by end walls  24  which extend upwardly from base  18  along their ends  26  and by side walls  28  which extend upwardly from base  18  along sides  30  to form tapered towers  32  at opposite sides of recess  22 . 
     One configuration of recess  22  is illustrated by FIGS. 2 and 3. The tops of recess  22  are located at the apex of towers  32 , with a recess top  34  running therebetween. The configuration and size of recess top  34  is selected to allow the desired type and size of pipe while excluding undesired types and sizes. As illustrated in the Figures, recess top  34  is curved in the vertical dimension while being substantially flat in the horizontal direction. Recess  22  is further defined by recess side walls  36 . Providing the recess with recess side walls  36  defining the recess allows the supporting device  16  to be used on sloping roofs or with a sloping pipe yet distributes substantially equal weight of the pipe over the flat base area of device  16 . 
     Support structure  20  and base  18  can be manufactured of any suitable material known in the art, such as plastic materials, rubber materials, or metals. Preferably, the support structure  20  and base  18  are molded from a polycarbonate resin (PR) with additives to make it resistant to ultraviolet light. The thickness of the walls in these components, when they are made of PR, can range from about {fraction (1/10)} to about ⅛ inches. Preferably, the thickness is about ⅛ inches when supporting pipes up to 100 pounds per pipe supporting device. Other materials may require different wall thickness for similar loads. 
     Recess  22  can be configured for the expected size (e.g., diameter) of the pipe to be supported. Thus, the diameter of the recess ranges from about 1 inch to about 4 inches to support pipes ranging from about ½ to about 2¾ inches in diameter. For example, the diameter of the recess is about 3 and ⅞ inches when supporting a pipe with a diameter of about 3¾ inches. 
     The shape of recess  22  should be configured to accommodate the shape and size of the pipe. Accordingly, the shape of the recess can be substantially a u-shape or curvilinear shape. The angle of incline of the u-shape or curvilinear shape can be modified for the size and shape of the pipe as well as for the structural integrity of device  16 . 
     In a normal position, supported pipe  10  will fit into recess  22  and rest, as described below, on positioning means without touching the walls of the recess. Recess  22  is necessary to ensure that the supporting device  16  remains in position with respect to the pipe upon lateral movement of the pipe or upon lateral movement of the supporting device. Thus, if the pipe being supported moves laterally, it will contact the recess edge and move the supporting device along the roof with it. If the supporting device  16  is secured to the roof, the edge of the recess will hold the pipe against substantial lateral movement. For this reason, it is preferred that the recess be formed as illustrated rather than as a larger flat surface. 
     In certain pipe-support devices known in the art, a trough was formed in the bottom of recess  22  to receive a roller therein. See, for example, U.S. Pat. No. 4,502,653, the disclosure of which is incorporated herein by reference. Generally, the roller extended along the bottom of recess  22  and the trough was configured to provide a surface against which the roller could rotate. Unfortunately, there was no means for retaining the roller in the trough. Moreover, the roller often did not properly position the pipe within recess  22 , allowing pipe  10  to abut and rub the walls of recess  22 . 
     In the present invention, positioning means are located in the bottom of recess  22 . The positioning means serves several functions, including supporting the pipe  10  and allowing it to move in the pipe&#39;s axial direction. The positioning means also help distribute the weight of the pipe. Importantly, the positioning means also positions the supported pipe in a transverse direction between the walls of recess  22  as illustrated in FIG.  5 . Preferably, positioning means centers pipe  10  in the transverse direction so that the pipe does not contact or abut the recess walls. 
     Preferably, the positioning means illustrated in FIG. 5 is employed in the present invention. The illustrated positioning means includes a shaft  40  on which sleeve  42  rotates. To accommodate the positioning means illustrated in FIGS.  5  and  6 , recess  22  is modified as shown. For other positioning means, recess  22  can be altered to allow for the specific configuration of the positioning means. 
     In FIGS. 5 and 6, shaft  40  can have any desired configuration which provides a surface on which sleeve  42  rotates. Preferably, the shaft has a cylindrical shape with a circular cross section having a diameter ranging from about 1 inch to about 3 inches and a length depending on the size of recess  22 . Preferably, shaft  40  has a diameter of about {fraction (9/16)} inches. 
     The shaft is constructed of any suitable material known in the art. Suitable materials include those which minimize friction and resistance between the shaft and the sleeve, such as steel, stainless steel, or plastic materials. Preferably, stainless steel or glass-filled nylons are employed as the material for the shaft. 
     The ends of shaft  40  are held in place by any suitable restricting means located in recess  22 . The restricting means insure that the shaft (and consequently sleeve  42 ) are fixed relative to recess  22  and do not fall out during transport or installation. One restricting means includes collar  46  formed in the side wall adjacent the shaft  40 , such as that illustrated in FIGS. 5 and 6. Collar  46  comprises lower wall  50  and side wall  52  in which the end of shaft  40  rests. To place the shaft  40  (with sleeve  42  already placed thereon) into pipe-supporting device  16 , the sleeve  42  is pushed down through collar  46 . Once pushed onto lower wall  50 , the end of shaft  40  is locked into place by ribs or protrusions  44  in side wall  52  immediately above shaft  40 . If necessary, the shaft  40  can also be kept in place by strap  54  which extends around and encircles pipe  10 . 
     Sleeve  42  can be of any suitable configuration with an inner surface rotating around the outer surface of shaft  40  and with the sleeve outer surface supporting and positioning the pipe. An optional washer  56  can be placed on shaft  40  between sleeve  42  and recess  22 . Preferably, the sleeve  42  has a shape where the end portions have a diameter larger than the middle portions. Alternatively, the sleeve can contain more than one component provided that the component(s) located near the end of the shaft  40  are larger in diameter than the component(s) located proximate the middle of the shaft  40 . More preferably, the sleeve employed in the present invention is a single component with a small diameter in the middle which tapers to a larger diameter at the ends, as illustrated in FIGS. 5 and 6. The specific smaller and larger diameters, as well as the degree of the taper, depends on the size of the pipe to be supported. 
     The sleeve  42  is constructed from any suitable material known in the art. Suitable materials include those which are resilient enough to not be deformed by the pipe yet which minimize friction with the shaft and with the pipe. Suitable materials include plastic materials, such as polycarbonate, TEFLON (fluoropolomers), or glass-filled nylons. Preferably, polycarbonate resin is employed as the material for the sleeve. 
     The pipe supporting device  16  of the present invention can have alternative configurations. For example, it could have more than one shaft/sleeve combination—such as successive shaft/sleeves in the axial direction—used as the positioning means. Additionally, the pipe supporting device could have more than one recess, each with its own positioning means, placed in series (to support adjacent portions of a pipe) or in parallel (to support pipes running side-by-side). Additional structural supports, such as cross-supports  58  which help distribute the pipe weight, can be added to the pipe supporting device of the present invention to increase the structural integrity thereof. 
     Having described the details of the present invention, the invention defined by the appended claims is not to be limited by the above details, as many apparent variations thereof are possible without departing from the spirit or scope thereof.