Abstract:
An access floor system including an access floor panel having a top surface and an opposite bottom surface and at least one pedestal. The pedestal includes a base portion for resting on a subfloor, a head portion and a jack interconnecting the base portion and the head portion, the head portion having an upper surface for engaging the bottom surface of the floor panel. A selected one of the upper surface of the head portion of the pedestal or the bottom surface of the floor panel comprises a protrusion extending therefrom, and the other of the upper surface of the head portion or bottom surface of the floor panel defines a receptacle therein, the receptacle being of a size to complementarily and detachably engage the protrusion. It is noted that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims pursuant to 37 C.F.R. § 1.72(b).

Description:
RELATED U.S. APPLICATION DATA  
       [0001]    This application claims priority to U.S. provisional application Ser. No. 60/204,034, filed on May 15, 2000. The 60/204,034 provisional patent application is herein incorporated by this reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to access floor systems, and specifically to an access floor system which provides for detachable engagement between a pedestal and an access floor panel.  
           [0004]    2. Background Art  
           [0005]    Access flooring systems, also referred to as “raised floors,” “computer floors,” or “elevated floors,” have been utilized in a variety of applications in which a plenum beneath a floor surface is required by the user. Traditionally, access floor systems have been heavily utilized in computer room environments, in which a significant amount of interstitial space beneath the floor structure is required to accommodate and manage cables, components and other electrical services. Increasingly, however, demand for access floor systems has grown as usage of access floor systems has become more common in other building environments such as cleanrooms, equipment rooms, and general purpose office space. Such applications benefit from other uses of the access floor plenum, such as the capability of housing HVAC componentry or other mechanical services.  
           [0006]    An access floor system is made up of a plurality of individual square, modular access floor panels supported by adjustable height pedestals. When assembled, the access floor panels form a deck upon which the contents of the room rest. Each access floor panel is a modular unit, which is removable, replaceable, and interchangeable with other panels. Each panel is constructed to meet the performance requirements of the entire floor system, including, for example, load bearing requirements, combustibility resistance, and corrosion resistance.  
           [0007]    Installation of an access floor system in any building environment results in a reduction in the amount of occupant space in the building interior due to the plenum area created by the floor system. Whether the floor system is retrofitted into an existing building for which access floors were not originally contemplated, or installed in a building which was designed and constructed to accommodate conventional access floors, efficient space utilization is always a design concern. Existing buildings, for example, often have low ceilings which will not allow for utilization of an access floor system with pedestals measuring 24” or more in height. In construction of new buildings, significant savings may be realized from optimization of the access floor system profile for a given overall plenum area requirement. For example, a reduction in an access floor system overall height of 75 mm, assuming a 40-story building with access floors on each level, results in a reduction in building height of 3 meters, or the equivalent of one story. Thus, it is advantageous to provide an access flooring system which provides efficient space utilization for a range of specified plenum area requirements.  
           [0008]    Access floor systems of the prior art generally include a range of components, including access floor panels, pedestals, connection hardware for attaching the panels to pedestals, and stringers, which maintain consistent spacing between pedestal when individual panels are removed for replacement or to access the plenum. Difficulty and expense of installation, removal and servicing of the access floor system is obviously related to the complexity involved in assembly of the access floor system and is often proportional to the number of discrete components needed to fabricate the system. Therefore, it is also advantageous to provide an access floor system with a minimum of constituent parts, in an effort to simplify installation and service expense and to reduce the level of experience and expertise required of installation personnel.  
           [0009]    Access floor systems of the prior art generally suffer from one or more deficiencies, including inter-panel misalignment, difficulty in installation or replacement of individual access floor panels within the access floor system, difficulty of the height adjustment of panels within the floor system, and overall instability of the floor system in response to lateral loads.  
         SUMMARY OF THE INVENTION  
         [0010]    The disadvantages of the prior art are overcome by the present invention which, in one aspect, is an access floor system having at least one access floor panel which is supported by at least one pedestal. Each access floor panel has a top surface that forms the access floor surface and an opposite bottom surface. Each pedestal is comprised of a base portion which rests on the subfloor of the room, a head portion which engages the bottom surface of the access floor panel, and a jack interconnecting the base portion and the head portion.  
           [0011]    The head portion of the pedestal and the bottom surface of the panel have a male-female mechanical connection therebetween. A protrusion extends from either the upper surface of the head portion of the pedestal or the bottom surface of the floor panel. The component not having the protrusion defines a corresponding receptacle of a size to complementarily and detachably engage the protrusion. Thus, the protrusion may be provided on the upper surface of the head portion, with a corresponding receptacle defined by the bottom surface of the floor panel, or vice versa.  
           [0012]    In another aspect, the jack has an adjustable jack length between the base portion and the head portion. The jack is adjustable along a substantially vertical longitudinal axis between the base portion and the head portion.  
           [0013]    In one embodiment, the jack comprises a first sleeve attached to the base portion and a complementary second sleeve attached to the head portion, the second sleeve being of a size to complementarily interconnect to the first sleeve. In one embodiment, the first and second sleeves are in coaxial telescopic relation to each other, such that at least a portion of the inner surface of the first sleeve engages at least a portion of the outer surface of the second sleeve. The first and second sleeves are cylindrical, and at least a portion of both the inner surface of the first sleeve and the outer surface of the second sleeve are complementarily threaded so that the first and second sleeves are in adjustable threaded engagement with each other. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a partial cross-sectional perspective view of an embodiment of the improved access floor system according to the present invention with certain parts broken away for clarity and other elements shown in phantom lines.  
         [0015]    [0015]FIG. 2 is a section taken along line  2 - 2  in FIG. 1.  
         [0016]    [0016]FIG. 3 is a top plan view of an embodiment of the head portion of the pedestal according to the present invention.  
         [0017]    [0017]FIG. 4 is a side elevational view of FIG. 3.  
         [0018]    [0018]FIG. 5 is a section taken along line  5 - 5  in FIG. 3.  
         [0019]    [0019]FIG. 6 is a cross-sectional side elevational view of an embodiment of the receptacle in FIG. 2 according to the present invention.  
         [0020]    [0020]FIG. 7 is a top plan view of an embodiment of the base portion of the pedestal according to the present invention.  
         [0021]    [0021]FIG. 8 is a side elevational view of FIG. 7.  
         [0022]    [0022]FIG. 9 is a section taken along line  9 - 9  in FIG. 7.  
         [0023]    [0023]FIG. 10 is a sectional top plan view of a group of access floor panels assembled to form a portion of a floor system, with underlying pedestals shown in phantom lines. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, “a,” “an,” or “the” can mean one or more, depending upon the context in which it is used. The preferred embodiment is now described with reference to the figures, in which like numbers indicate like parts throughout the figures.  
         [0025]    Referring to FIG. 1, the invention comprises an improved access floor system  10  having at least one access floor panel  20  which is supported by at least one pedestal  30 . Typical installations of complete access floor systems  10  will fill an entire room, or an entire level of a building, with a matrix of access floor panels. As shown in FIGS. 1 and 10, in an embodiment having a plurality of square floor panels  20 , each panel  20  is supported at each of its four comers with a pedestal  30  which maintains the plenum space  12  between the subfloor  14  (shown in FIG. 2) and the access floor panels  20 . In such a configuration, each pedestal  30  may support corner of four adjoining or abutting access floor panels  20 . Other pedestal configurations utilizing more or fewer pedestals  30 , however, are possible, provided adequate load support is maintained.  
         [0026]    Referring now to FIGS. 1 and 2, each access floor panel  20  has a top surface  22  and an opposite bottom surface  24 . Access floor panels  20  may be constructed of a variety of materials. In some embodiments, the floor panel  20  includes an outer shell  26  constructed of sheet steel, aluminum or other suitable materials. The shell  26  may be filled with core material  28 , such as lightweight concrete, plastic, composite or wood, or may be left hollow. In other embodiments, the floor panel  20  may be constructed completely of solid wood or other structurally acceptable material. The top surface  22  of the floor panel  20  optionally may be covered with a covering (not shown), such as a high pressure laminate (“HPL”), vinyl, or carpet.  
         [0027]    Each pedestal  30  is comprised of a base portion  40  which rests on the subfloor  14 , a head portion  50  for engaging the access floor panel  20 , and a jack  60  interconnecting the base portion  40  and the head portion  50 . The jack  60  has a jack length L extending between the base and head portions  40 ,  50  which may be adjustable, such that the height of the pedestal  30 , and thus the plenum space  12  beneath the access floor system  10 , may be controlled by the user. The head portion  50  of the pedestal  30  and the bottom surface  24  of the floor panel  20  preferably have a male-female mechanical connection therebetween. A protrusion  70  extends from either the upper surface  52  of the head portion  50  of the pedestal  30  or the bottom surface  24  of the floor panel  20 . The component not having the protrusion  70  defines a corresponding receptacle  80  of a size to complementarily and detachably engage the protrusion  70 . Thus, as illustrated in the embodiments shown throughout the figures, the protrusion  70  may be provided on the upper surface  52  of the head portion  50 , with a corresponding receptacle  80  defined by the bottom surface  24  of the floor panel  20 .  
         [0028]    Alternatively, the protrusion  70  may be on the bottom surface  24  of the floor panel  20  with the corresponding receptacle  80  defined by the upper surface  52  of the head portion  50 . Another alternative is that the upper surface  52  of the head portion  50  has at least one protrusion  70  and at least one receptacle  80 , and that the bottom surface  24  of the floor panel  20  also has at least one receptacle  80  and at least one protrusion  70  capable of engaging the corresponding protrusion  70  or receptacle  80  on the other component. It is further contemplated that one comer of the floor panel  20  may include a protrusion  70  while another comer of the same panel  20  may include a receptacle  80 .  
         [0029]    As shown in FIGS.  3 - 5 , the head portion  50  of the pedestal  30  may be fabricated from a sheet metal blank, stamped or otherwise manufactured to the specifications described herein. The head portion  50  may also be fabricated of other materials, such as aluminum or hard plastic, as will be apparent to one skilled in the art. Optional holes or apertures  56  may be drilled or stamped into the head portion  50  to eliminate nonessential component weight, to allow for drainage of fluids through the head portion  50  or for any other desired purpose.  
         [0030]    The head portion  50  has an upper surface  52  which supports the access floor panel  20  and an opposite lower surface  54  which engages the jack  60 . In the illustrated embodiment, at least one protrusion  70 , which is sized to engage a corresponding receptacle  80  within the access floor panel  20 , depends from the upper surface  52  of the head portion  50 .  
         [0031]    In the illustrated embodiment, four protrusions  70  are provided on a square head portion  50  to allow for attachment of the head portion  50  to the comers of four adjacent square access floor panels  20 . The protrusions  70  are attached to the upper surface  52  of the head portion  50 . One skilled in the art will recognize that various fastening methods, including welding or adhesive or other mechanical or chemical fastening methods may be suitable for attaching the protrusions  70  to the head portion  50 . Alternatively, the protrusions  70  may be integral to the material which forms the head portion  50  itself. Additionally, though the head portion  50  is illustrated as being substantially square in shape, alternate shapes may be utilized, such as rectangular, round, oval, or any other suitable shape.  
         [0032]    Still referring to FIGS.  3 - 5 , the head portion  50  may be manufactured by stamping a sheet metal blank to form the desired shape, and protrusions  70  may be formed from the same blank of material from which the head portion  50  is manufactured. After forming, the protrusions  70  depend from the upper surface  52  of the head portion  50  and are capable of insertion into a corresponding receptacle  80  in the access floor panel  20 . As described in greater detail below, the protrusion  70  may be formed in a shape so that at least a portion of the protrusion  70  corresponds generally to at least a portion of the shape of the receptacle  80  to enable secure attachment between the pedestal  30  and access floor panel  20 .  
         [0033]    The head portion  50  may be provided in one embodiment with one or more optional embossments  32  to facilitate resistance welding of the jack  60  to the head portion  50 . In one embodiment, four embossments  32  are provided on the head portion  50  to facilitate manufacture of the pedestal  30 . The embossments  32  ensure consistent contact between the jack  60  and the head portion  50 , and provide concentrated contact areas which enable more reliable resistance welding of the head portion  50  to the jack  60 .  
         [0034]    Referring now to FIGS.  7 - 9 , the base portion  40  of the pedestal  30  is now described in detail. Like the head portion  50 , the base portion  40  may be fabricated from a sheet metal blank, stamped or otherwise manufactured to the specifications described herein or from any other suitable material. Holes or apertures  56  may be provided in the base portion  40  for any purpose, including facilitating attachment of the base portion  40  to the subfloor  14  for added stability. The base portion  40  has a bottom surface  42 , which contacts the building subfloor  14 , and an opposite top surface  44 , which engages the jack  60 .  
         [0035]    Optional embossments  32  which facilitate resistance welding may be also imparted to the base portion  40 , in a similar configuration to that described in connection with the head portion  50 . As illustrated in FIGS.  7 - 9 , the base portion  40  optionally may be provided with one or more finger tabs  46  to facilitate adjustment of the pedestal  30 . The finger tabs  46  may be provided to the base portion  40  by any desired method, including by welding or otherwise attaching the tabs  46 , or by stamping or otherwise manufacturing the finger tabs  46  from the same material from which the base portion  40  is manufactured. As described in further detail below, finger tabs  46  enable manual rotation of the base portion  40  with respect to the head portion  50  of the pedestal  30 , which in turn alters jack length L in the illustrated embodiment.  
         [0036]    Referring now to FIGS.  1 - 6 , the protrusion  70  and receptacle  80  are now described in detail. In one embodiment, the receptacle  80  may be integrally formed from the same material that comprises the floor panel  20 . For example, in embodiments wherein the outer shell  26  of the floor panel  20  is constructed of sheet metal, the receptacle  80  may be formed into the shell  26  itself by stamping the receptacle  80  into the sheet metal as part of the manufacturing process. In another embodiment, the receptacle  80  may be a separate bushing  82  inserted into the appropriate location on either the head portion  50  of the pedestal  30  or the floor panel  20 . Such a bushing  82  may be constructed of a variety of different materials, including metal, plastic or rubber.  
         [0037]    In one preferred embodiment, the receptacle  80  is a pliable bushing  82 , constructed of a plastic, nylon or hard rubber material which is capable of withstanding repeated deformation. In such an embodiment, the receptacle  80  should be capable of engaging and disengaging a protrusion  70  at least once without destroying the receptacle  80 . Preferably, a receptacle  80  material should be selected, such as those set forth above, that is capable of withstanding at least several years of normal use, including repeated engaging and disengaging of the protrusion  70 , without permanent deformation of the receptacle  80 . In a currently preferred embodiment, bushings  82  fabricated of nylon have been found to produce satisfactory results.  
         [0038]    [0038]FIGS. 1 and 2 illustrate an embodiment in which the receptacle  80  is a pliable bushing  82  embedded within the floor panel  20 , such that a small portion  84  of the receptacle  80  protrudes below the bottom surface  24  of the floor panel  20 . In such an embodiment, when used in an access floor system having a floor panel  20  and head portion  50  constructed of metal, contact between the metal panel  20  and the metal head portion  50  is minimized, thus decreasing grinding or squeaking which may occur when slight relative movement occurs in a metal-to-metal contact. Instead, as shown in FIG. 1, the protruding portion  84  of the receptacle  80  bears on the upper surface  52  of the head portion  50  and acts as a cushion, minimizing unwanted vibration and noise during use of the access floor system  10 . However, in other embodiments, the receptacle  80  may also be disposed within the floor panel  20  without protruding therefrom.  
         [0039]    Preferably, the receptacle  80  is capable of detachably engaging the protrusion  70 , such that repeated installation and removal of the access floor panel  20  is possible without substantial physical degradation of either the protrusion  70  or receptacle  80 . The figures illustrate one such embodiment of the protrusion  70  and receptacle  80 , having a repeatable snap-fit engagement. Referring to FIGS. 2 and 6, a receptacle  80  having a non-uniform inner bore  86  in cross-sectional side view is illustrated. The inner bore  86  of the receptacle  80  has a first inner diameter D 1  at the end of the receptacle  80  adjacent the bottom surface  24  of the floor panel  20 . The inner bore  86  also has a second inner diameter D 2 , which is larger than the first inner diameter D 1 , at a location internal to the receptacle  80 , forming a detent internal to the receptacle  80 . Thus, the inner bore  86  of the receptacle  80  is narrower at the point where the protrusion  70  enters the receptacle  80 , and becomes wider at a point of deeper insertion of the protrusion  70 .  
         [0040]    Such a receptacle  80  may be dimensioned to complementarily receive a protrusion  70  such as that illustrated in FIGS.  3 - 5 , which has a width W 2  adjacent its tip  72  which is greater than the width WI along the rest of its length  74 . In such an embodiment, the protrusion  70  is captured and retained within the receptacle  80  when the floor panel  20  is installed. As the protrusion  70  is inserted into the receptacle  80 , deformation of the inner bore  86  is required to pass the tip  72  of the protrusion  70  through the receptacle  80  and into the detent therein. By providing a protrusion tip  72  of a width W 2  which is greater than the smallest inner diameter D 1  of the receptacle inner bore  86 , but which fits within a notch  88  created by a step in the inner bore  86 , the desired snap-fit is created. In another embodiment, the protrusion  70  and receptacle  80  may be further dimensioned such that the selected receptacle material is stressed at levels below its elastic limit or yield point by insertion and removal of the protrusion  70 . The inner bore  86  may be dimensioned so that the second inner diameter D 2  is slightly less than the width W 2  of the tip  72  of the protrusion  70 , so that when the protrusion  70  is fully inserted into the receptacle  80 , the inner bore  86  may be slightly deformed by the tip  72  of the protrusion  70 , preferably below the elastic limit or yield point of the receptacle material. Referring now to FIG. 2, in such an embodiment, the receptacle  80  exerts a retaining force on the protrusion  70 , tending to hold the panel  20  in place. Alternatively, the protrusion  70  and receptacle  80  may be dimensioned such that, when assembled, there is clearance between the protrusion  70  and receptacle  80 .  
         [0041]    In other embodiments, either the receptacle  80 , protrusion  70 , or both may have a uniform shape in cross section. For example, the protrusion  70  may have a substantially uniform width along its entire length. Optionally, in such an embodiment, at least part of the inner bore  86  of the receptacle  80  may contact the protrusion  70  to ensure a tight and secure engagement between the protrusion  70  and receptacle  80 . In such a configuration, the protrusion  70  causes a slight deformation of the receptacle  80 , or interference fit, when the floor panel  20  is installed.  
         [0042]    The illustrated embodiment depicts an arrangement wherein the protrusion  70  is located on the head portion  50  and the receptacle  80  is within the panel  20 . Alternately, the locations of the protrusion  70  and receptacle  80  may be reversed, such that the protrusion  70  is located on the floor panel  20  and the receptacle  80  is fixed to the head portion  50 . Additionally, though the receptacle  80  has been described herein as being pliable and engaging a rigid protrusion  70 , the receptacle  80  may be rigid and may engage a pliable protrusion  70 . Alternatively, both the receptacle  80  and protrusion  70  may be pliable, or both may be rigid.  
         [0043]    As shown in FIGS. 1 and 2, between the head portion  50  and base portion  40 , a jack  60  is provided which enables the installer of the access floor system to control the height above the subfloor at which the access floor panels  20  are maintained. The jack  60  has a jack length L that is adjustable between a minimum and maximum jack length. The jack  60  is adjustable along a substantially vertical longitudinal axis A between the base portion  40  and the head portion  50 . Adjustability of individual pedestals  30  allows the installer to control the height of the entire access floor system  10 , and allows the installer to account for inconsistent subfloor conditions by adjusting the height of individual pedestals  30  to produce a uniformly level surface condition.  
         [0044]    In one embodiment, each pedestal  30  includes a jack  60  having a first sleeve  62  and a complementary second sleeve  66 . The first sleeve  62  is attached to the top surface  44  of the base portion  40 , and the second sleeve  66  is attached to the lower surface  54  of the head portion  50 . If embossments  32  are provided on the base portion  40  and head portion  50  as described above, the corresponding sleeves  62 ,  66  may be easily affixed to those structures by resistance welding. Other methods of attachment, mechanical, chemical or otherwise, may also be utilized to assemble the pedestal  30 .  
         [0045]    In the illustrated embodiment, the first sleeve  62  and second sleeve  66  are cylindrical, however, other shapes, including but not limited to square, rectangular, or oval cross sections, will be apparent to one skilled in the art. The second sleeve  66  is sized to complementarily interconnect with the first sleeve  62 , such that the first and second sleeves  62 ,  66  operate in coaxial telescopic relation to each other. In such an embodiment, the first sleeve  62  may be larger than the second sleeve  66 , such that the inner dimensions of the second sleeve  66  are at least slightly larger than the outer dimensions of the first sleeve  62 . Alternatively, the relative dimensions of the first and second sleeves  62 ,  66  may be opposite of the illustrated embodiment, such that the first sleeve  62  fits within the second sleeve  66 . The jack length L may then be adjusted by moving the first and second sleeves  62 ,  66  relative to each other along the axis A.  
         [0046]    In the illustrated embodiment, at least a portion of the inner surface  64  of the first sleeve  62  and at least a portion of the outer surface  68  of the second sleeve  66  comprise complementary threads  69  so that the first and second sleeves  62 ,  66  are in threaded engagement with each other. In such an embodiment, the jack length L may be adjusted by rotating the first and second sleeves  62 ,  66  relative to each other. When the desired jack length L is reached, the frictional forces between the threaded sleeves are sufficient to maintain the position of the jack  60 , and thereby maintain the desired jack length L.  
         [0047]    Such a configuration facilitates assembly and height adjustment of access floor panels  20  by allowing the installer convenient and precise control over the spacing between the head portion  50  and the base portion  40  of the pedestal  30 . To adjust the height of any pedestal  30 , the installer need only remove an adjacent access floor panel  20 , grasp the base portion  40 , and rotate the base portion  40  in either direction.  
         [0048]    As best shown in FIGS.  3 - 5 , to facilitate adjustment of jack length L by the installer, one or more finger tabs  46  or other grasping means may be provided which protrude from the base portion  40 . Such finger tabs  46  may be welded to the top surface  44  of the base portion  40 , stamped from the material which makes up the base portion  40  itself, or provided by other securing means (not shown). Alternatively, finger tabs or other grasping means may be provided on the jack  60 , such as on the exterior of the first sleeve  62 .  
         [0049]    When adjustment of the jack  60  produces a satisfactory floor surface and plenum space  12 , the base portion  40  may optionally be fastened to the subfloor  14  by adhesive, bolts, or other means (not shown). As discussed in more detail below, attachment of the base portion  40  to the subfloor  14  contributes to added stability of the system  10  under normal use conditions.  
         [0050]    The above description pertains to one preferred embodiment of the jack  60 , and is not intended to foreclose other embodiments of the jack  60 . For example, a strip gear jack, automotive jack or other jack (not shown) may be utilized. As a further example, sleeves without threads (not shown) may be utilized instead of the threaded sleeves described above, and a plurality of holes (not shown) may be formed along the longitudinal sides of the first and second sleeves  62 ,  66 , such that the sleeves may be pinned to one another through selected aligned holes to maintain a selected jack length L. Other embodiments of the jack  60 , which are regarded as being within the scope of the present invention, will be apparent to those skilled in the art.  
         [0051]    According to the invention, stability of the access floor system  10  under lateral loading conditions is improved over the existing state of the art. For purposes of this specification, “lateral loading” refers to forces exerted on the access floor panel  20  parallel to its top surface  22 , and perpendicular to the longitudinal axis A of the pedestals  30 . Lateral loading of access floor systems is a common occurrence caused primarily by foot traffic or by sliding or rolling of objects from one individual panel  20  to a neighboring panel  20 . Attachment of the base portion  40  to the subfloor  14  as described above provides some contribution to lateral stability. Lateral stability is drastically improved, however, by providing a pedestal  30  having a wide diameter jack  60  and large base portion  40  and head portion  50  footprints.  
         [0052]    A large-footprint base portion  40  and head portion  50  improves resistance of the access floor system  10  to lateral loading by reducing the tendency of the pedestal  30  to tip and rock under lateral loads. Additionally, use of an increased outer diameter in the components which make up the jack  60 , i.e., the first and second sleeves  62 ,  66  as described in the embodiment above, reduces the stresses concentrated at the points of connection between the jack  60  and the head portion  50  and base portion  40 . Thus, a wide-stance pedestal  30  with a more rigid frame is produced according to the invention disclosed herein. In turn, instability and rocking of the access floor system  10  under lateral loads applied during use of the access floor system  10  are minimized.  
         [0053]    An additional feature of the improved access floor system  10  is that the system provides for automatic alignment of the access floor panels  20  with respect to one another. Because the location of the protrusions  70  on the head portion  50  and the receptacles  80  within the access floor panels  20  may be controlled, those locations may be selected to provide consistent spacing between neighboring panels  20 .  
         [0054]    The above described pedestal  30  and its constituent components may be utilized to construct access floor system  10  using a broad variety of access floor panels  20 . For example, the “low profile” access floor system which is depicted in the figures may be created, in which the panel  20  has a nominal thickness of ½” and is a 12” ×12” square in its outer perimeter. As shown in FIG. 1, the panel  20  in such a system is a composite laminate in which a core of cement board, particle board, plastic core material or other similar material is encased in sheet metal. Other access floor system configurations may also be constructed according to the invention, incorporating access floor panels  20  made of steel, cement, aluminum, wood, or other materials. The invention may be utilized in panel systems having any selected panel dimensions, including “standard” 24” ×24” panels. Additionally, a plurality of plenum dimensions may be provided by different embodiments of the invention. The illustrated embodiment provides an adjustable plenum which ranges from 1.250” to 2.125”. Alternate systems may be constructed according to the invention which provide 24” or more of plenum space.  
         [0055]    Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims.