Abstract:
One aspect of the present invention provides a poke-through assembly for installation in a hole in a floor structure. The floor structure defines a floor in a first working environment and a ceiling in a second working environment. The poke-through assembly includes at least one intumescent member and an intumescent cover assembly. The intumescent member being disposed at least partially within the hole in the floor structure. Also, the intumescent cover assembly including a base plate and a retainer member. The base plate supports the intumescent member and the retainer limits and/or restricts expansion of the intumescent member. Further, the retainer is adjustably secured to the base plate in a plurality of positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/868,945 filed on Dec. 7, 2006. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    A poke-through assembly or simply a “poke-through” is a common device that enables power, data or other cabling to pass through a hole between floors in a building, generally a concrete floor. A thermal barrier in the form of a fire and/or smoke retardant element, particularly intumescent material, is incorporated within the poke-through. The intumescent serves as a fire-stop and expands to seal any remaining space within the poke-through and the surrounding hole in which it is installed. This helps prevent the spread of fire and/or smoke from one floor to the next. 
         [0003]    Contemporary poke-throughs provide access between an upper floor and an immediately adjacent lower floor. The poke-through assembly is usually installed with a cover which serves as a cap or lid for the hole. Also, the poke-through generally includes an upper frame or basket designed to create an easily accessible cavity or recess at the surface of the upper floor. Alternatively, such frames or baskets can be used to hold power and/or data receptacles therein. The upper frame is generally metallic and is in direct contact with a cover plate or the upper flooring itself. A lower end of the contemporary poke-through is connected to a junction box accessible to an adjacent lower floor. The lower end generally has open sides that hold intumescent material. Such an open configuration for the intumescent allows it to fully expand when heated, and theoretically seal the poke-through hole. However, the intumescent material does not generally provide a stable rigid support structure, especially when heated substantially. Thus, the expanding intumescent material will squeeze its way out the bottom of the poke-through assembly and big chunks of the material can break-off. This causes a loss of intumescent material, which can compromise the fire-stop capability for which it was intended. 
         [0004]    There is therefore a need for a poke-through assembly that prevents the loss of and/or provides a retainer for the intumescent material. Such an improved assembly must be inexpensive, and manufactured and installed easily. Additionally, it would be beneficial if the improved assembly or at least portions thereof could be retrofit into existing poke-throughs without replacing the entire existing assembly. 
       SUMMARY OF THE INVENTION 
       [0005]    One aspect of the present invention provides a poke-through assembly for installation in a hole in a floor structure. The floor structure defines a floor in a first working environment and a ceiling in a second working environment. The poke-through assembly includes at least one intumescent member and an intumescent cover assembly. The intumescent member being disposed at least partially within the hole in the floor structure. Also, the intumescent cover assembly including a base plate and a retainer member. The base plate supports the intumescent member and the retainer limits and/or restricts expansion of the intumescent member. Further, the retainer is adjustably secured to the base plate in a plurality of positions. 
         [0006]    Another aspect of the present invention provides a poke-through assembly, which includes an upper frame, at least one intumescent member, a base plate, and a cup. The intumescent member being disposed below the upper frame and the base plate supporting the intumescent member. The cup positioned to retain expanded portions of the intumescent member. Also, a vertical position of the cup is adjustable relative to the base plate. 
         [0007]    Additionally, the poke-through assembly can include a retainer member or cup that circumferentially surrounds at least a portion of the intumescent member. Also, the retainer member or cup can circumferentially surround substantially the entire intumescent member. Further, each of the adjustably secured retainer or cup positions can correspond to a different amount of the intumescent member being surrounded by the retainer member. Further still, the retainer or cup can include a plurality of apertures for allowing expansion of a portion of the intumescent member through the apertures. Yet further still, the retainer or cup can include a bracket or collar formed thereon for supporting an adjustable fastener, which allows the retainer or cup to be adjustably secured. The bracket or collar can extend from a base portion of the retainer or cup. 
         [0008]    The poke-through assembly can further include a conduit fixedly secured to the base plate and adjustably secured to the retainer member or cup. Also, a vertical position of the retainer member or cup can be adjustable relative to the conduit. 
         [0009]    These and other objects, features, and advantages of this invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIGS. 1   a  and  1   b  are respectively top and bottom perspective views of one embodiment of a retainer portion of the intumescent cover in accordance with the present invention. 
           [0011]      FIGS. 2   a  and  2   b  are respectively top and bottom perspective views of another embodiment of a retainer portion of the intumescent cover in accordance with the present invention. 
           [0012]      FIG. 3  is a top perspective view of one embodiment of a support member of the intumescent cover in accordance with the present invention. 
           [0013]      FIG. 4  is a bottom partially exploded perspective view of a poke-through assembly including an intumescent cover in accordance with the present invention. 
           [0014]      FIG. 5  is a bottom perspective assembled view of the poke-through assembly shown in  FIG. 4 . 
           [0015]      FIG. 6  is a top perspective view of the poke-through assembly shown in  FIG. 5  inserted in a concrete slab, with a cut-away of a portion of the slab. 
           [0016]      FIG. 7  is a side section view of the poke-through assembly shown in  FIG. 4  inserted in a thick concrete slab with the intumescent retainer secured in a lower position. 
           [0017]      FIG. 8  is a side section view of the poke-through assembly shown in  FIG. 4  inserted in a thin concrete slab with the intumescent retainer secured in the highest position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    This invention pertains to a poke-through assembly with improved heat isolation features, particularly in the form of a cover assembly for retaining the intumescent material used in a fire-rated electrical poke-through. Also, the features of the present invention are relatively inexpensive, manufactured easily and quickly installed. Additionally, the features of the present invention can be retrofit into existing poke-throughs without replacing the entire assembly. 
         [0019]      FIGS. 1   a  and  1   b  show a first portion of an intumescent cover assembly, namely an intumescent cover, cup or retainer  100 , in accordance with one embodiment of the present invention. The retainer  100 , preferably includes an annular band  110  that is attached to a lower plate  120 . The annular band  110  rises vertically from the lower plate  120 , together forming a retainer or cup that can cover the lower portions of the poke-through assembly, and particularly the intumescent material (shown in  FIGS. 5-8 ). When fully assembled in the poke-through, often time neither the band  110  nor the lower plate  120  is in direct contact with the intumescent material. 
         [0020]    The band  110  is preferably formed with an overlapping structure  118 . The overlap  118  provides a region  112  for spot welding or otherwise securing the two ends of the band  110  to maintain a closed annular form. Also, the band  100  is preferably secured to the lower plate  120 . The overlapping structure  118  could alternatively be eliminated, so the annular band  110  has no overlap and thus a constant thickness. Thus, two ends of an otherwise flat band bent to form an annular band could be spot welded or bonded; or the union between the plate  120  and the band  110  could be welded or bonded to maintain the shape and position of the band  110 . 
         [0021]      FIGS. 2   a  and  2   b  show an intumescent retainer  101 , in accordance with an alternative embodiment of the present invention. The annular band  111  preferably includes apertures  115  in the form of holes or perforations, through which intumescent material can expand during a fire. Preferably, the intumescent material while expanding should be able to extrude through or past the apertures  115  and abut the inner side-walls of the poke-through hole. In this way, the band  111  still allows radial expansion of intumescent material which provides a fire stop, but restricts and retains a portion of the material. Also, once the intumescent material expands through the aperture  115 , the band  111  acts as a structural reinforcement for the intumescent member(s). This reinforcement can help prevent large chunks of intumescent material from breaking off or away from the overall assembly. 
         [0022]    It should be understood that while perforations  115  are shown to be circular almost any shape or size could be provided. Also, the perforations  115  need not be distributed evenly across most of the band  110 . For example, the perforations  115  could be provided only on a portion of the band  110 , such as near the top rim or bottom portion thereof. Further, the perforations  115  could be larger or smaller than that shown, and they need not all be the same size or shape. Additionally, the band  110  could be formed of a wire mesh, thus increasing the amount of intumescent that can pass therethrough. 
         [0023]      FIG. 3  shows a second portion of an intumescent cover assembly, namely an intumescent support member  150 . The support member  150  includes a support or base plate  152  that is preferably secured directly below the intumescent member  200 . As shown in  FIG. 4 , apertures  156  can receive a rod or bolt  322  for coupling the support member  150  to the upper receptacle portion  300 . An upper surface of the base plate  152  is generally in direct contact with the intumescent member  200 , thereby holding it under the upper receptacle portion  300 . However, the intumescent member  200  is preferably not rigidly fastened to the support member  150  or any other element in the poke-through assembly. The support member  150  also preferably includes at least one elongate support column or conduit  154  for holding the retainer  100 ,  101  in a select vertical position relative to the intumescent member  200 . As shown in  FIG. 3 , the conduit  154  is formed as a centrally positioned conduit member for passing power cables  350  therethrough. 
         [0024]    With reference to  FIGS. 1   a,    1   b,    2   a  and  2   b,  preferably the lower plate  120  includes apertures  122 ,  125  and  128 . The lower plate apertures  122 ,  125 ,  128  primarily provide passage for other parts of the assembly. Preferably, those apertures  122 ,  125  and  128  are sized to limit as much as possible the passage of expanding intumescent material. As shown in  FIG. 4 , apertures  122  can receive a rod or bolt  322  for coupling the lower plate  120 , along with the base plate  152  to the upper receptacle portion  300 . In this way, the retainer  100 ,  101  and base plate  152  are secured to the upper poke-through assembly, holding and/or retaining the intumescent material  200  without being directly secured to it. Additionally, apertures  128  allow the passage therethrough of cables, such as communication cables  355 . In contrast, aperture  125  preferably provides passage for power cables  350 . 
         [0025]    As shown in  FIGS. 1   b  and  2   b,  the retainer  100 ,  101  preferably includes a collar  140  for receiving and being mounted on the conduit  154  and securing the retainer  100 ,  100  in a fixed position thereto. Preferably, a simple fastener  142  is provided, which can be easily adjusted in order to configure the assembly as desired. The aperture  125  is preferably coaxially aligned with the attachment collar  140  for mating with the conduit  154 . The conduit  154  preferably communicates with and is coupled to the junction box  500  positioned below, as shown in  FIGS. 4-8 . Alternatively, rather than being supported by a collar  140 , fastener  142  could be supported by a non-annular bracket. 
         [0026]    As shown in  FIGS. 5 and 6 , the retainer  100  preferably encloses substantially all of the lower and side surfaces of the intumescent material  200 . However, alternatively a portion of the intumescent, such as an upper portion, may remain uncovered (as shown in  FIGS. 7 and 8 ). Such an upper gap can function similar to apertures  115 , in allow expanding intumescent material to expand beyond the perimeter of the retainer  100 .  FIG. 6  shows the poke-through assembly  10  installed in a floor structure  20 . Similarly,  FIGS. 7 and 8  show the contrast between an installation in a first thicker floor  20   a  and a second thinner floor  20   b.  It should be understood that the assembly  10  of the present invention could be used in even thinner or thicker floors than that shown.  FIGS. 7 and 8  also particularly illustrate advantages and of the present invention and how it can be configured to suit particular circumstances. 
         [0027]    As shown in  FIG. 7 , some installations in thicker floors  20   a,  provide sufficient space Y within the poke-through hole  22 , below the upper receptacle portion  300 , to contain all or most of the intumescent member  200 . Preferably, the retainer  100  is installed so as to be positioned just below the lower surface of the floor  20   a.  Thus, an upper lip of annular band  110  sits just inside the hole  22  and the lower plate  120  is positioned a distance X below the lower surface of the floor structure  20   a.  This configuration provides a significant portion of the side surfaces of intumescent member  200  to be directly exposed to the inner walls of the hole  22 . Thus, when and if the intumescent member  200  is heated, it can radially expand and abut the inner walls and provide its fire-stop capabilities. Without the retainer  100  of the present invention, expanding intumescent material  200  would ooze out the bottom of the poke-through assembly  10 . Also, even if just a bottom plate where provided without the band  110 , intumescent material  200  could squeeze through the gap X and potentially separate from the assembly. 
         [0028]    As shown in  FIG. 8 , occasionally installation in a thinner floor structure  20   b  will leave the intumescent material  200  protruding from the bottom of the hole  22 . In a configuration as shown in  FIG. 8 , without retainer  100  even a minor loss of intumescent material  200  could mean it no longer engages the side walls of the hole  22 , thus reducing the sealing and/or fire-stop capability of the assembly. According, the retainer can be mounted with its base  120  closer to the base plate  152 , once again leaving the upper lip of annular band  110  sitting just inside hole  22 . This configuration will still “catch” much of the expanding intumescent material  200  and control or guide its release (expansion). 
         [0029]    While the retainer  100  shown forms a cup-like member, with various openings and cutouts, it should be understood that this element could have many variations known in the art. Additionally, while the retainer  100  can be made of various materials, it is preferably made of stainless steel, die-cast zinc or aluminum. 
         [0030]    Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be applied therein by one skilled in the art without departing from the scope or spirit of the invention.