Abstract:
A poke-through device for installation in a hole in a floor structure. The floor structure defined by a floor in a first working environment and a ceiling in a second working environment. The poke-through device includes a basket, thermal barrier, lower plate and at least one coupling member. The basket including a coupling support surface. The thermal barrier being disposed below the basket. The lower plate supporting the thermal barrier. Also, the at least one coupling member extending through the thermal barrier and securing the basket to the lower plate. The coupling member including an upper portion disposed within the basket. The upper portion including an undersurface, wherein a first portion of the undersurface is in direct contact with the support surface and a second portion of the undersurface does not directly engage the basket.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/829,160 filed on Oct. 12, 2006. 

   BACKGROUND OF THE INVENTION 
   A poke-through device or simply a “poke-through” is a common device that enables power, data or other cabling to pass through a hole in a floor of a structure, 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 to seal the floor opening in the event of a fire. This helps prevent a fire or the smoke from spreading from one floor to the next. 
   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. Intumescent material is generally used between the upper basket and the lower end. Also, the upper and lower portions of the poke-through are secured with a number of metallic bolts, screws or other fasteners that pass through the intervening intumescent material. However, the intumescent material does not provide a stable support structure, especially when heated substantially. Thus, the fasteners provide a more durable coupling for the upper and lower portions of the poke-through. 
   While the intumescent material acts well as a thermal barrier, the metallic fasteners pass through the thermal barrier and conduct heat to the upper portions of the poke-through. As the heads of the fasteners are generally in direct contact with the metallic upper basket, portions of the adjacent upper flooring can overheat from the conductive heat transfer. 
   There is therefore a need for a poke-through device that provides improved heat isolation features. Such heat isolation features preferably minimize and/or reduce conductive heat transfer within the poke-through that bypasses the traditional thermal barrier. Such improved heat isolation features must be inexpensive, manufactured easily and quickly installed. Additionally, it would be beneficial if the improved features could be retrofit into existing poke-throughs without replacing the entire assembly. 
   SUMMARY OF THE INVENTION 
   One aspect of the present invention provides a poke-through device for installation in a hole in a floor structure. The floor structure is defined by a floor in a first working environment and a ceiling in a second working environment. The poke-through device includes a basket, thermal barrier, lower plate and at least one coupling member. The basket includes a coupling support surface. The thermal barrier is disposed below the basket. Also, the at least one coupling member extends through the thermal barrier and secures the basket to the lower plate. The coupling member includes an upper portion disposed within the basket. The upper portion includes an undersurface, wherein a first portion of the undersurface is in direct contact with the support surface and a second portion of the undersurface does not directly engage the basket. 
   Another aspect of the present invention includes a poke-through device including a receptacle-receiving basket, an intumescent member, a base member and at least one fastener assembly. The receptacle-receiving basket includes a coupling bracket. The intumescent member is disposed below the basket. The base member supports the intumescent member. Also, the at least one fastener assembly extends through the intumescent member and secures the intumescent member between the basket and the base member. The fastener assembly includes an upper head disposed within the basket, wherein a first portion of the fastener assembly is in direct contact with the coupling bracket and a second portion of the fastener assembly does not directly engage the coupling bracket. 
   Additionally, the poke-through device of the present invention can have the coupling member include a head on at least one end and a dispersion plate disposed between the head and the support surface. The undersurface of the upper portion can be a downward facing surface of the dispersion plate. The dispersion plate can be formed of a ceramic-fiber washer. Also, coupling support surface can be an upper surface of at least one support member integrally formed with the basket. The support member can protrude upwardly toward the first working environment from a base of the basket. Also, the support member can protrude inwardly from an outer portion of the basket. Further, the support member can include a tab for holding the dispersion plate in a pre-selected position. 
   Further, the poke-through device can include a second thermal barrier disposed at least partially above the coupling member. The dispersion plate can be an annular washer. Also, the dispersion plate can be sized to conform to at least a portion of an inner peripheral surface of the basket. The basket can include ribs that interlock with the dispersion plate for positioning the dispersion plate. 
   Further still, the fastener assembly can include a dispersion plate disposed between the head and the coupling bracket. Also, the coupling bracket can include an upper surface for engaging the fastener assembly first portion. The coupling bracket can protrude upwardly toward the first working environment from a base of the basket. Also, the coupling bracket can protrude inwardly from an outer portion of the basket. The coupling bracket can further include a tab for holding the dispersion plate in a pre-selected position. The poke-through device can include an additional intumescent member disposed at least partially above the fastener assembly. Further, the dispersion plate can be an annular member. The basket can include ribs that interlock with the dispersion plate for positioning the dispersion plate. 
   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 
       FIG. 1  is a top perspective assembled view of one embodiment of the poke-through assembly of the present invention with a cover assembly and conduit structures. 
       FIG. 2  is a top partially exploded perspective view of the poke-through assembly and cover assembly shown in  FIG. 1 , without the lower assembly. 
       FIG. 3  is a top perspective relief view of a stand-off coupling mount shown at A in  FIG. 2 . 
       FIG. 4   a  is a top perspective relief view of a stand-off coupling mount assembled with a screw and washer, as shown at B in  FIG. 2 . 
       FIG. 4   b  is a top perspective relief view as shown in  FIG. 4   a , with an additional washer. 
       FIG. 5  is a top perspective assembled view of a second embodiment of the poke-through assembly of the present invention with a cover assembly and conduit structures. 
       FIG. 6  is a top partially exploded perspective view of the poke-through assembly and cover assembly shown in  FIG. 5 , without the lower assembly. 
       FIG. 7  is a top perspective relief view of an alternative stand-off coupling mount shown at A 1  in  FIG. 6 . 
       FIG. 8  is a top perspective view of the lower portions of the poke-through assembly shown in  FIG. 6 , assembled with screws and a dispersion ring. 
       FIG. 9  is a top perspective relief view of the alternative stand-off coupling mount, as shown at B 1  in  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   This invention pertains to a poke-through device that provides improved heat isolation features, particularly in the form of a stand-off coupling mount that improves heat isolation. 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. 
     FIG. 1  shows a poke-through device  10  with a cover assembly  20  and lower conduit elements  30  secured thereto. As shown, the poke-through preferably includes a basket  100 , a thermal barrier  200  and a lower end plate  300 . Also shown are portions of the stand-off coupling mount  120  and an upper thermal barrier  210 . The exploded view in  FIG. 2  shows some additional elements of the assembly in  FIG. 1 . In particular, the basket  100  is shown unobstructed with the cover assembly  20 , upper thermal barrier  210  and a coupling member  400  separated there from. Also, more clearly shown in  FIG. 2  are two stand-off coupling mounts  120 , preferably secured to a lower portion of the basket  100 . The basket  100  preferably is made to receive one or more receptacles and associated connectors, components and supporting brackets. However, basket  100  can also be configured as a furniture feed, without receptacles, providing access between floors for cabling and/or conduit. While the basket  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. For example, the peripheral side walls of the basket  100  need not be continuous, but preferably cover a substantial portion of the floor hole in which it is installed. Similarly, fewer or additional openings or cutouts could be provided and the basket  100  can have a non-cylindrical shape. Additionally, while the basket  100  can be made of various materials, it is preferably made of die-cast zinc or aluminum. 
   The poke-through also preferably includes at least one thermal barrier  200  in the form of a fire/smoke retardation or intumescent member. Thermal barrier  200  is bounded on its lower side by lower end plate  300  and on its upper side by the basket  100 . The three components are preferably held together via at least one coupling member  400  as shown. The thermal barrier  200  is configured with a series of passageways therethrough (not shown). Larger and smaller openings pass vertically through the material for passing data, power or other cabling, as is known in the art. At least one of the small openings passing therethrough is occupied by a coupling member shaft  402 . When the poke-through is assembled, preferably an additional upper thermal barrier  210  is contained above the coupling member and within the basket  100 . 
   The coupling member  400 , shown in  FIG. 2 , includes a screw or bolt with a central shaft  402 , an upper head  404  and a lower threaded portion  406 . Preferably a stainless steel screw is used, as such parts are readily available, very durable and relatively heat resistant as compared to other metals. However, it should be understood that although a common screw/bolt is shown in  FIG. 2  a more unique fastener could be used for the coupling member  400 . The coupling member  400  also includes a load/heat dispersion plate  420 , that is sized to receive a central shaft  402  of the coupling member  400  and support the upper head  402 . 
     FIGS. 3 ,  4   a  and  4   b  show more detail, as indicated at A and B in  FIG. 2 , of the stand-off coupling mount  120  and its interaction with a coupling member  400 . The coupling mount  120  is preferably located at a lower portion  110  of the basket  100 . The coupling mount  120  includes a central aperture  125  for passage of the shaft  402 . Also, the coupling preferably includes one or more stand-off posts  130  intended to support the coupling member  400 . While the embodiment shown in  FIGS. 3 and 4   a  show four stand-off posts  130 , it should be understood that greater or fewer posts could be provided so long as the coupling member  400  is supported and sufficient thermal dissipation is provided. The upper portion of the stand-off posts  130  preferably includes a contact surface  132  intended to directly engage an underside or undersurface of an upper portion of the coupling member  400 . Thus, as illustrated in  FIGS. 4   a  and  4   b , the undersurface of either the dispersion plate  420  in  FIG. 4   a  or the additional plate or washer  430  in  FIG. 4   b  directly engage the contact surface  132 . The embodiments shown in  FIGS. 3 ,  4   a  and  4   b  further include optional reinforcing and/or stabilizing features for the coupling mount  120 . In particular, the central cylindrical boss  122 , which is either integrally formed with or fixedly attached to the posts  130  provides support for the coupling mount. Also, the extension tabs  138  help position and stabilize the dispersion plate  420 . 
   Thus, the coupling member shaft  402  passes through an aperture  125  in the basket  100 . The head  404  of the coupling member sits on the dispersion plate  420 , which in turn rests on either the stand-off contact surface  132  ( FIG. 4   a ) or rests on washer  430  ( FIG. 4   b ). In this way, the stand-off posts  130  support the dispersion plate  420  and/or the washer  430  with minimum surface contact between the metallic head  404  and the basket  100 . This is intended to reduce the conductive heat transfer between those elements. In addition to potentially dispersing thermal energy conducted through the shaft  402  and head  404 , the dispersion plate  420  also acts as a load dispersing member, like a traditional washer. Thus, the configuration, shape and materials used for the dispersion plate  420 , as well as the coupling member  400  can prolong the amount of time it will take for the basket  100  to reach its critical temperature or melting point. 
   Since the poke-through  10  is placed below floor level, the bottom of the coupling shaft  406  reaches the highest temperature during a fire. The long shank of the preferably stainless steel screw  402  transfers heat to the top portion, primarily by conduction, passing through the thermal barrier  200 . Thus, the temperature at the head  404  is transferred (again mainly by conduction) to the supporting structure. In this embodiment, by providing a contact surface  132  with a smaller surface area than the downwardly facing undersurface of the head  404 , heat conduction from the coupling member  400  to the basket  100  is reduced. Additionally, providing additional portions of the coupling member  400 , particularly its undersurface, that do not directly engage either the coupling mount  120  or the basket  100 , promotes convective cooling. 
   The dispersion plate  420  shown in  FIGS. 2 and 4   a , as well as the additional plate  430  shown in  FIG. 4   b , are in the form of an annular washer. However, other shapes and sizes for these plates could alternatively be used. It should be understood that while the dispersion plate  420  is shown to be separate from the shaft  402  and/or head  404 , the two elements could be integrally formed or joined together chemically or mechanically. Preferably, the dispersion plate  420  is also stainless steel, however other materials such as ceramics, plastics or heat resistant fibers could be used. The dispersion plate  420  material is preferably selected for its low thermal conductivity, strong durability and/or low cost. Additional washer  430  is preferably a heat resistant material, such as ceramic fiber, and used in combination with a stainless steel dispersion plate  420 . 
   Preferably the washer  430  provides an additional thermal barrier for the convective heat transfer in the poke-through assembly. Washer  430  is preferably made of a heat resistant material such as a refractory ceramic fiber, for example NUTEC FIBRATEC®, FIBERFAX®, CERWOOL®, KAOWOOL® and others. Such materials can typically be manufactured in a paper or pad form which can be cut into almost any shape, is light weight, relatively inexpensive and particularly suited for this application. For example, such materials can typically withstand temperatures of 2000° F. to 3000° F. and can certainly function well as at least a temporary thermal barrier. By resisting conductive heat transfer directly between the coupling member  400  and the basket  100 , the upper portions of the poke-through  10  will not heat as quickly. The washer  430  can be made up entirely of refractory ceramic fibers or can have a layered configuration such that the ceramic paper is included as one or more of the substrate layers. Alternatively, all or a portion of the washer  430  can include other materials. As a further alternative, portions of washer  430  could either include gaps in the ceramic material or simply be reinforced by separate areas of ceramic material. 
     FIGS. 5 and 6  show an alternative design for the poke-through devices  11 . As shown, the poke-through  11  preferably includes a basket  101 , a thermal barrier  201  and a lower end plate  301 . Also shown are portions of the alternative stand-off coupling mounts  121  and a modified upper thermal barrier  211 . The exploded view in  FIG. 6  shows some additional elements of the assembly in  FIG. 5 . In particular, the basket  101  is shown unobstructed with a coupling member  401  separated there from. Also, more clearly shown in  FIG. 6  are two alternative stand-off coupling mounts  121 , preferably secured to a lower portion of the basket  101 . While two mounts  121  are shown, it should he understood that additional mounts could be included. Ultimately, the mounts  121  need to support the coupling member  401 , while minimizing contact surfaces. Also shown is an alternative dispersion plate  421 , which is significantly larger than the earlier version. The alternative dispersion plate  421  is sized to accommodate an inner diameter of the basket  101 . In this embodiment the basket  101  is designed with stabilizing features such as protruding ribs that mate with indents on the alternative dispersion plate  421 . Also, the coupling member shaft  403  is made to pass through a notch  422 . It should be understood that the alternative dispersion plate  421  could be made to have a circular aperture, rather than just a notch. Additionally, the same design considerations mentioned above are preferably used when selecting materials for the plate  421 . 
     FIGS. 7-9  show even further details of the alternative poke-through  11 . In particular,  FIG. 7  shows details of an alternative stand-off coupling mount  121  as shown at A 1  in  FIG. 6 . The stand-off support structure  131  has a more cylindrical form and is incorporated around a lower structure  111  of the basket  101 . As with the previous embodiment, contact surface  133  is located at the top of the support structure  131 , with notches or gaps  123  in the lower structure  111  creating open spaces to minimize the thermal transfer surfaces and promote convective cooling.  FIG. 9  shows details shown at B 1  in  FIG. 8 . In particular  FIG. 9  shows how plate  421  sits on top of the contact surface  133  and is secured to the coupling member head  403 . As with the first embodiment, this additional embodiment includes heat isolation features that serve to increase the amount of time for the conductive heat transfer process to take place in the support frame while reducing its temperature by convectional cooling in order to help meet regional testing requirements. Also, as with the earlier embodiments, an additional ceramic fiber washer or dispersion plate  430  can be used between dispersion plate  421  and the support structure  131 . 
   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.