Modular stair assembly

Information

  • Patent Grant
  • 6763912
  • Patent Number
    6,763,912
  • Date Filed
    Thursday, August 29, 2002
    21 years ago
  • Date Issued
    Tuesday, July 20, 2004
    20 years ago
Abstract
A modular stair assembly includes a stair module and at least one of a transportation module, deck module, handrail module, extension deck module, and extension handrail module that can be interconnected in various configurations to suite a wide variety of different applications.
Description




BACKGROUND OF THE INVENTION




This invention relates to stair assemblies, and more particularly to modular stair assemblies with different modules or components that can be connected together to suit a wide variety of different applications.




Prefabricated stair assemblies are often designed for a single application or particular use. For example, it is common to prefabricate stair assemblies for new homes, trailer homes, and so on. These stair assemblies are typically constructed of cement, and are therefore relatively heavy in weight, difficult to transport, position, and secure in place. The removal of such stair assemblies is labor-intensive and often requires special equipment. For temporary structures or structures at temporary locations, such as platforms for presentations or speeches, trailer homes, and so on, the ability to install and/or remove the stair assembly for various applications in a quick and efficient manner is desirous.




BRIEF SUMMARY OF THE INVENTION




In accordance with one aspect of the invention, a modular stair assembly comprises a stair module having a pair of spaced stair support frames with each stair support frame including an elongate base member, a rear upright support member connected to a rear end of the base member, a stringer extending diagonally from a forward end of the base member to an upper end of the rear support member, and a plurality of L-shaped risers connected to the stringer. Each riser has a vertical riser portion that extends upwardly from the stringer and a horizontal riser portion that extends rearwardly from the vertical riser portion toward the stringer. The vertical and horizontal riser portions are rigidly fixed together. A plurality of steps extend between the stair support frames and are supported by the horizontal riser portions.




In accordance with a further aspect of the invention, at least one of a transportation module, deck module, handrail module, extension deck module, and extension handrail module can be provided with the stair module so that the modular stair assembly is readily adaptable to a wide variety of different applications.











BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS




The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:





FIG. 1

is an isometric view of a modular stair assembly according to a first embodiment of the present invention;





FIG. 2

is an isometric view of the modular stair assembly with an attached transportation module in accordance with the invention;





FIG. 3

is an isometric view of the modular stair assembly with an attached handrail module in accordance with the invention;





FIG. 4

is an isometric view of the modular stair assembly with an attached deck module in accordance with the invention;





FIG. 5

is an isometric view of the modular stair assembly with attached deck and handrail modules in accordance with the invention;





FIG. 6

is an isometric exploded view of the modular stair assembly of

FIG. 5

as viewed from the left side thereof,





FIG. 7

is an isometric view of the deck module;





FIG. 8

is a side elevational view of a pair of modular stair assemblies in back-to-back relationship;





FIG. 9

is an isometric view of a modular stair assembly with an attached extension deck module and extension handrail module in accordance with a further embodiment of the invention;





FIG. 10

is an isometric view of a modular stair assembly with an extension deck module and a pair of extension handrail modules in accordance with an even further embodiment of the invention;





FIG. 11

is an isometric view of the extension deck module as shown in the

FIG. 10

embodiment;





FIG. 12

is a left side isometric view of a stair step in accordance with the invention that can form part of the modular stair assemblies of the previous embodiments;





FIG. 13

is a side elevational view of the stair step; and





FIG. 14

is a bottom plan view of the stair step.











The invention will now be described in greater detail with reference to the drawings, wherein like parts throughout the drawing figures are represented by like numerals.




DETAILED DESCRIPTION OF THE INVENTION




Referring now to the drawings, and to

FIG. 1

in particular, a modular stair assembly


5


in accordance with the present invention is illustrated. The modular stair assembly includes a stair module


10


with a pair of spaced stair support frames


12


and


14


, a plurality of steps


16


extending between the support frames, and a cross member or brace


18


extending diagonally between the support frames


12


and


14


for added structural support.




With additional reference to

FIG. 6

, each of the stair support frames


12


and


14


is generally triangular in shape and includes an elongate base member


20


that contacts a horizontal support surface, such as a floor, platform, ground, and so on, a rear upright support member


22


connected to a rear end of the base member


20


, and a stringer


24


extending diagonally from a forward end of the base member


20


to an upper end of the rear support member


22


. Preferably, the base member


20


, the rear upright support member


22


and the stringer


24


are L-shaped in cross section and formed of a metal material, such powder-coated steel or anodized aluminum to inhibit rust and/or discoloration. It will be understood that the structural members can be constructed with other materials and/or finishes. A plurality of L-shaped risers


26


are connected to the stringer


24


for supporting the steps


16


. Each riser


26


is preferably constructed of a single piece of material and includes a vertical riser portion


28


and a horizontal riser portion


30


that is rigidly connected to the vertical riser portion. With the exception of the forward-most riser


26


, the ends


32


and


34


of the risers


26


are securely connected to the stringer, preferably through welding, although fasteners, brackets, or other securing means can be used. As shown, the forward-most riser


26


has one end


32


that is also connected to the stringer


24


and another end


34


that is connected to the forward end of the base member


20


at a more forward position than the stringer


24


. Each of the horizontal riser portions


30


includes a pair of spaced apertures


36


through which threaded bolts or studs


38


are received for securing the steps


16


to the risers


26


.




The steps


16


are preferably trapezoidal in shape with an upper surface


40


that is wider than a lower surface


42


. Each step


16


is preferably constructed of a slip-resistant cement material with the studs


38


embedded therein and extending downwardly from the lower surface


42


. It will be understood that the steps


16


can be constructed of other materials and shapes.




With the above-described arrangement, the stair module


10


is relatively light weight, rigid, and easily transported and erected when the individual components are shipped separately and bolted or otherwise connected together at the installation site. When the stair module


10


is used for temporary structures or displays, the bolted configuration allows for relatively quick and easy disassembly.




With reference now to

FIG. 2

, a transportation module


48


in the form of wheels or casters


50


can be connected to the base members


20


of the support frames


12


and


14


to facilitate movement and positioning of the modular stair assembly


5


. This configuration is especially advantageous when the modular stair assembly


5


is installed at temporary locations or must be moved for accessing or preventing access to different parts of a structure. The wheels


50


can be of the locking and/or swiveling type. The wheels


50


may additionally or alternatively be of the retracting type so that the frame can be solidly supported on a surface when positioned at a desired location.




With reference now to

FIGS. 3 and 6

, the modular stair assembly


5


can include a handrail module


60


. As shown, the handrail module


60


has a front upright post


62


, a rear upright post


64


, a lower support bar


66


that extends between the front and rear posts, an upper rail


68


that connects to and extends beyond the front and rear posts, and spindles


70


that extend between the lower support bar


66


and the upper rail


68


. The components of the handrail module


60


are preferably constructed of a durable material, such as steel or aluminum, and can be separately formed and rigidly connected together through welding, fasteners, or other attachment means. Alternatively, the handrail module


60


may be formed as a unitary structure of plastic or other material. The front upright post


62


is preferably connected to a front mounting tab


72


that is rigidly connected to and extends upwardly from the base member


20


of each support frame


12


,


14


. The rear upright post


64


is preferably connected to the rear upright support member


22


of one of the support frames


12


,


14


. The rear upright support members


22


and the front mounting tabs


72


preferably have mounting holes


74


that are in alignment with holes


76


(

FIG. 6

) on the front and rear posts


62


and


64


, respectively, for receiving a bolt or other fastener to thereby secure the handrail module


60


to one or both of the support frames


12


,


14


.




With reference now to

FIGS. 4

,


6


and


7


, the modular stair assembly


5


can include a deck module


80


. As shown, the deck module


80


has a pair of spaced deck frames


82


and


84


and a plurality of platform portions


86


extending between the deck frames. Although not shown, a cross member can extend diagonally between the deck frames


82


and


84


for added structural support.




Each of the deck frames


82


and


84


is of generally C-shaped configuration and includes a lower support member


88


, a rear upright support member


90


connected to a rear end of the lower support member


88


, and an upper support member


92


connected to an upper end of the upright support member


90


. Preferably, the lower, upper and rear upright support members are L-shaped in cross section and formed of a metal material, such powder-coated steel or anodized aluminum to inhibit rust and/or discoloration. A lower connection tab


94


is secured to a forward end of each of the lower support members


88


and extends generally upwardly therefrom. An upper connection tab


96


is secured to a forward end of each of the upper support members


92


and extends generally forwardly therefrom. A hole


98


is preferably formed in each of the connection tabs


94


,


96


and corresponding holes


100


(

FIG. 6

) are preferably formed in the rear upright support members


22


through which threaded bolts or other fasteners are received for securing the deck module


80


to the stair module


10


. It will be understood that the deck module can be connected to the stair module through other fastening means, such as clamping, welding, adhesive bonding, and so on.




Each of the upper support members


92


preferably includes pairs of spaced apertures


102


through which threaded bolts or studs (not shown) are received for securing the platform portions


86


to the upper support members


92


. It will be understood that more or less pairs of spaced apertures


102


can be used depending on the length of the deck module


80


and thus the total number of platform portions


86


. As with the rear upright support members


22


of the stair support frames


12


and


14


, the rear upright support members


90


of the deck frames


82


and


84


have mounting holes


105


that are in alignment with holes


76


(

FIG. 6

) on the rear posts


64


of the handrail module


60


for receiving a bolt or other fastener to thereby secure the handrail module


60


to one or both of the stair support frames


12


,


14


and the deck frames


82


,


84


. It will be understood that the structural members can be constructed with other materials and/or finishes. It will be further understood that the deck frames are not limited to the C-shaped configuration.




The platform portions


86


are preferably similar in construction to the steps


16


and are preferably trapezoidal in shape with an upper surface


104


that is wider than a lower surface


106


. Each platform portion


86


is preferably constructed of a slip-resistant cement material with studs (not shown) embedded therein and extending downwardly from the lower surface


106


. It will be understood that the platform portions


86


can be constructed of other materials and shapes.




Although only three steps


16


and two platform portions


86


are shown for the stair and deck modules, respectively, it will be understood that more or less steps and/or platform portions can be used, it being understood that the structural members would be lengthened and/or shortened to accommodate the different numbers of steps and/or platform portions, as shown for example in FIG.


9


.




The modular stair assembly


5


can include one or more of the modules as previously described. As shown in

FIG. 1

, the modular stair assembly includes the stair module


10


. In

FIG. 2

, a transportation module


48


is added. In

FIG. 3

, the modular stair assembly


5


includes a combination of the stair module


10


and the handrail module


60


. In

FIG. 4

, the modular stair assembly includes a combination of the stair module


10


and the deck module


80


. In

FIGS. 5 and 6

, the modular stair assembly includes a combination of the stair module


10


, the handrail module


60


, and the deck module


80


. Other combinations of the different modules can be used depending on the particular requirements at the installation site.




With reference now to

FIG. 8

, a modular stair assembly


110


in accordance with a further embodiment of the invention includes two modular stair assemblies


5


in back-to-back relation to form a raised platform


112


that can be accessed from either stair module


10


. As in the previous embodiment, each of the stair assemblies


5


may be arranged with a single stair module


10


or different combinations of modules to produce the desired effect.




Referring now to

FIGS. 9 and 11

, a modular stair assembly


120


in accordance with a further embodiment of the invention includes a stair module


122


, a deck module


124


connected to a rear end of the stair module, a handrail module


126


connected to a forward end of the stair module


122


and a rearward end of the deck module


124


, an extension deck module


128


connected to a rear end of the deck module


124


, and an extension handrail module


130


connected to a side of the extension deck module


128


. The stair module


122


, deck module


124


and handrail module


126


are similar in construction to the stair module


10


, deck module


80


and handrail module


60


, respectively, with the exception that some of the structural components are lengthened to accommodate an increased height of the stair module


122


and the increased number of steps


16


. The size of the structural components may also be increased to accommodate more weight.




The extension deck module


128


has a pair of spaced extension deck frames


132


and


134


, cross members


136


,


138


and


140


extending diagonally between the extension deck frames


132


and


134


, and a plurality of platform portions


86


extending between the extension deck frames.




Each of the extension deck frames


132


and


134


is preferably generally square or rectangular in shape and includes a lower support member


142


, an upper support member


144


, a front upright support member


146


and a rear upright support member


148


extending between forward and rearward portions, respectively, of the lower support member


142


and the upper support member


144


. Preferably, the lower, upper, front and rear support members are L-shaped in cross section and formed of a metal material, such powder-coated steel or anodized aluminum. It will be understood that the support members can be constructed of other cross sectional shapes and/or materials.




As shown, the cross member


136


extends diagonally from a lower portion of the front upright support member


146


of the extension deck frame


132


to an upper portion of the front upright support member


146


of the extension deck frame


134


. Likewise, the cross members


138


and


140


extend diagonally from a lower portion of one of the rear upright support members


148


to an upper portion of the other rear upright support member


148


. Although three cross members are shown, it will be understood that more or less cross members can be provided.




As with the deck module


80


, each of the upper support members


144


of the extension deck module


128


preferably includes pairs of spaced apertures (not shown) through which threaded bolts or studs (not shown) are received for securing the platform portions


86


to the upper support members


144


. It will be understood that more or less pairs of spaced apertures can be used depending on the length of the extension deck module


128


and thus the total number of platform portions


86


.




The extension deck module


128


is preferably connected to the rear of the deck module


124


through fasteners, such as threaded bolts and nuts, but may alternatively be connected through clamping, welding, adhesive bonding, or other fastening means.




As shown in

FIG. 9

, the extension handrail module


130


has a front upright post


150


, a rear upright post


154


, a lower support bar


156


that extends between the front and rear posts, an upper rail


158


that extends between the front and rear posts, and spindles


160


that extend between the lower support bar


156


and the upper rail


158


. The components of the extension handrail module


130


are preferably constructed of a durable material, such as steel or aluminum, and can be separately formed and rigidly connected together through welding, fasteners, or other attachment means. Alternatively, the extension handrail module


130


may be formed as a unitary structure of plastic or other material. The front upright post


150


is preferably connected to the front upright support member


146


of one or both support frames


132


,


134


(

FIG. 11

) Likewise, the rear upright post


154


is preferably connected to the rear upright support member


148


of one or both support frames


132


,


134


through fasteners, such as threaded bolts and nuts, but may alternatively be connected together through clamping, welding, adhesive bonding, or other fastening means. The use of two or more extension handrail modules with the extension deck module


128


is contemplated.




With the above-described embodiment, one or more stair modules


122


, deck modules


124


, handrail modules


126


, extension deck modules


128


, and/or extension handrail modules


130


can be connected together in different combinations and orientations to accommodate a wide variety of circumstances and applications. As in the

FIG. 8

embodiment, two modular stair assemblies


120


can be positioned in back-to-back relation to form an extended raised platform that can be accessed from both stair modules


122


.




With reference now to

FIG. 10

, a modular stair assembly


160


in accordance with a further embodiment of the invention is illustrated. The modular stair assembly


160


is similar in construction to the modular stair assembly


120


previously described, with the exception that the extended deck module


128


is connected to a side of the deck module


124


and a second extension handrail module


162


is connected to a forward portion of the extended deck module


128


. The handrail module


126


is also repositioned on an opposite side of the stair module


122


and the deck module


124


.




With the above-described embodiments, it can be readily seen that the modular stair assembly can be configured in a wide variety of different ways to accommodate a wide variety of different applications.




Turning now to

FIGS. 12-14

, a step


170


in accordance with a further embodiment of the invention is illustrated. The step


170


can be used with any of the stair modules of the previously described embodiments and includes a tread portion


172


and an overhang portion


174


that extends generally downwardly from the tread portion


172


. Openings


176


are formed in a lower surface


178


of the tread portion


172


. The openings


176


are adapted to receive threaded studs or bolts (not shown) for connecting the steps


170


with the risers


26


as previously described. Alternatively, studs, bolts, clamps, or other fastening means can be integrally molded with the steps


1700


for connection with the risers


26


. The step


170


is preferably constructed of a slip-resistant cement material, although other materials may be used.




It will be understood that terms of orientation and/or position as may be used herein such as vertical, horizontal, front, rear, upper, lower, and so on, as well as their respective derivatives and equivalent terms refer to relative, rather than absolute, orientations and/or positions. Moreover, it will be understood that the term “preferably” as used herein refers to an exemplary arrangement of the invention, and therefore is not intended to portray the invention in any limiting sense.




It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It will be understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.



Claims
  • 1. A modular stair assembly, comprising:a stair module supportable and freestanding on a surface, the stair module having a plurality of steps removably connected between a pair of spaced side frames; and a plurality of optional modules removably connected to the stair module to result in different structures of the stair assembly to suit a wide variety of applications, the optional modules comprising a deck module, wherein the deck module comprises: a generally horizontal platform portion substantially coplanar to an uppermost step of the stair module; and a pair of spaced C-shaped side frames each having, a generally, horizontally extending bottom member having a free proximal end supportable on a surface, a generally, horizontally extending top member having a free proximal end supporting the platform portion, a generally vertical member extending between distal ends of the bottom and top members, and connection tabs extending from the proximal ends of the bottom and top members for removably engaging the side frames of the stair module.
  • 2. The modular stair assembly of claim 1, wherein the plurality of optional modules further includes an extension deck module having a generally horizontal platform portion substantially coplanar to the platform portion of the deck module.
  • 3. The modular stair assembly of claim 2, wherein the plurality of optional modules further includes a handrail module removably connectable to the stair module and an extension handrail module removably connectable to the extension deck module.
  • 4. The modular stair assembly of claim 1, wherein the plurality of optional modules further includes a handrail module that extends in a generally horizontal direction a length generally coterminous with the side frames of the stair module.
  • 5. The modular stair assembly of claim 1, wherein the plurality of optional modules further includes a handrail module that extends in a generally horizontal direction a length generally coterminous with a length defined by the stair module connected to the deck module.
  • 6. A modular stair assembly, comprising:a stair module supportable and freestanding on a surface, the stair module having a plurality of steps removably connected between a pair of spaced side frames; a module removably connected to the stair module wherein the module is a first handrail module extending in a generally horizontal direction a length generally coterminous with the side frames of the stair module, or a deck module, the deck module comprising: a generally horizontal platform portion substantially coplanar to an uppermost step of the stair module; and a pair of spaced C-shaped side frames each having a generally, horizontally extending bottom member having a free proximal end supportable on a surface, a generally, horizontally extending top member having a free proximal end supporting the platform portion, a generally vertical member extending between distal ends of the bottom and top members, and connection tabs extending from the proximal ends of the bottom and top members removably engaging the side frames of the stair module; and optionally a second handrail module removably connected to the stair module and removably connected to the deck module, the second handrail module extending in a generally horizontal direction a length generally coterminous with a length defined by the stair module connected to the deck module.
  • 7. The modular stair assembly of claim 6 wherein the deck module is removably connected to an extension deck module having a generally horizontal platform portion substantially coplanar to the platform portion of the deck module.
  • 8. The modular stair assembly of claim 7 wherein the extension deck module is removably connected to a third handrail module.
  • 9. A modular stair assembly, comprising:a stair module supportable and freestanding on a surface, the stair module having a plurality of steps removably connected between a pair of spaced side frames; and at least one of a plurality of modules removably connected to the stair module to result in different structures of the stair assembly to suit a wide variety of applications, the plurality of modules comprising: a first handrail module extending in a generally horizontal direction a length generally coterminous with the side frames of the stair module; a deck module, the deck module comprising: a generally horizontal platform portion substantially coplanar to an uppermost step of the stair module; and a pair of spaced C-shaped side frames each having a generally, horizontally extending bottom member having a free proximal end supportable on a surface, a generally, horizontally extending top member having a free proximal end supporting the platform portion, generally vertical member extending between distal ends of the bottom and top members, and connection tabs extending from the proximal ends of the bottom and top members removably engaging the side frames of the stair module; and a second handrail module extending in a generally horizontal direction a length generally coterminous with a length defined by the stair module connected to the deck module.
US Referenced Citations (33)
Number Name Date Kind
307551 Jackson Nov 1884 A
569464 Moore Oct 1896 A
750156 Bois Jan 1904 A
838266 McKee et al. Dec 1906 A
960412 Sandblom Jun 1910 A
1063216 Rendle et al. Jun 1913 A
1475777 Ballenger Nov 1923 A
1835759 Cook Dec 1931 A
1888686 O'Donnell Nov 1932 A
2150586 McAver Mar 1939 A
2205859 O'Donnell Jun 1940 A
2218523 Byington Oct 1940 A
2281698 Kogl May 1942 A
2287561 Page Jun 1942 A
2696027 Ryland Dec 1954 A
2949703 Katzmarek Aug 1960 A
3196997 Hager Jul 1965 A
3747708 Wenger et al. Jul 1973 A
3750351 Greenburg Aug 1973 A
4042064 Lobb Aug 1977 A
4464870 Crepeau Aug 1984 A
4580777 Johnson Apr 1986 A
4635416 Ayala Jan 1987 A
4819391 Tassin et al. Apr 1989 A
4823529 Canfield Apr 1989 A
4873802 Dahowski Oct 1989 A
5293722 Reimann Mar 1994 A
5778610 Berg Jul 1998 A
5806254 Bennett Sep 1998 A
5833576 Henni Nov 1998 A
5899032 Buzby May 1999 A
6205722 Bromley Mar 2001 B1
6295772 Whitson Oct 2001 B1