U.S. patent application number 12/134393 was filed with the patent office on 2009-12-10 for removable stairway for an elevated platform and method.
Invention is credited to Livingston Elwood Atkins, III, David J. Laws.
Application Number | 20090300994 12/134393 |
Document ID | / |
Family ID | 41399026 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090300994 |
Kind Code |
A1 |
Atkins, III; Livingston Elwood ;
et al. |
December 10, 2009 |
REMOVABLE STAIRWAY FOR AN ELEVATED PLATFORM AND METHOD
Abstract
A removable stairway device configured for attachment to a
platform includes a removable step attachable to the platform and
extendable from the platform in cantilever fashion. A gap is formed
between the step and the elevated deck of the platform when the
removable step is attached to the platform. A lock plate is
pivotally coupled to the step. The lock plate pivots to cover the
gap between the step and the elevated deck. A flange extends from
the lock plate and engages a side of the platform to lock the step
to the platform when the step is attached to the platform and the
lock plate is pivoted to cover the gap.
Inventors: |
Atkins, III; Livingston Elwood;
(Orem, UT) ; Laws; David J.; (Provo, UT) |
Correspondence
Address: |
THORPE NORTH & WESTERN, LLP.
P.O. Box 1219
SANDY
UT
84091-1219
US
|
Family ID: |
41399026 |
Appl. No.: |
12/134393 |
Filed: |
June 6, 2008 |
Current U.S.
Class: |
52/7 ; 182/206;
52/183; 52/582.2; 52/741.2 |
Current CPC
Class: |
E04H 3/28 20130101 |
Class at
Publication: |
52/7 ; 52/582.2;
52/183; 52/741.2; 182/206 |
International
Class: |
E04H 3/28 20060101
E04H003/28 |
Claims
1. A removable stairway device configured for a platform,
comprising: a) a platform having an elevated deck and a plurality
of legs supporting the deck; b) a step removably attachable to the
platform and extendable from the platform in cantilever fashion; c)
a gap between the step and the elevated deck of the platform; d) a
lock plate pivotally coupled to the step and pivotal to cover the
gap between the step and the elevated deck; and e) a flange
extending from the lock plate and engageable with a side of the
platform to lock the step against the platform when the step is
attached to the platform and the lock plate is pivoted to cover the
gap.
2. A device in accordance with claim 1, wherein the flange is
positioned on the lock plate so as to form an interference fit with
the side of the platform when the lock plate is pivoted to cover
the gap and the flange engages the side of the platform.
3. A device in accordance with claim 2, wherein the flange includes
a beveled end that engages and guides the flange along the side of
the platform as the lock plate is pivoted to cover the gap.
4. A device in accordance with claim 3, wherein the flange resists
rotation by the step due to upward and downward forces applied to
the step when the lock plate is pivoted to cover the gap and the
flange engages the side of the platform.
5. A device in accordance with claim 1, wherein the step further
includes a cantilever support bracket having an attachment end
removably attachable to the platform and extendable therefrom in
cantilever fashion and configured to carry the step.
6. A device in accordance with claim 1, further comprising: a stair
stringer extending downward from the step and including a plurality
of relatively lower, substantially parallel, and approximately
equally spaced steps with respect to the removable step.
7. A device in accordance with claim 1, wherein the lock plate is
positionable in a substantially flush position with respect to an
upper surface of the elevated deck of the platform when the lock
plate is pivoted to cover the gap.
8. A portable elevated platform, comprising: a) a deck elevatable
to a desired height by a plurality of legs; b) a stairway removably
coupled to the deck and configured to provide access from a lower
surface to the deck, the stairway further comprising: i) a step
removably attachable to the deck and extendable from the deck in
cantilever fashion; ii) a stair stringer extending downward from
the step and including a plurality of relatively lower steps with
respect to the removable step; iii) a gap between the step and the
deck when the stairway is coupled to the deck; iv) a lock plate
pivotally coupled to the step and pivotal to cover the gap between
the step and the deck; and v) a flange extending from the lock
plate and engageable with a side of the platform when the step is
attached to the platform and the lock plate is pivoted to cover the
gap.
9. A device in accordance with claim 8, wherein the flange is
positioned on the lock plate so as to form an interference fit with
the side of the platform when the lock plate is pivoted to cover
the gap and the flange engages the side of the platform.
10. A device in accordance with claim 8, wherein the flange
includes a beveled end that engages and guides the flange along the
side of the platform as the lock plate is pivoted to cover the
gap.
11. A device in accordance with claim 8, wherein the step further
includes a cantilever support bracket having an attachment end
removably attachable to the platform and extendable therefrom in
cantilever fashion and configured to carry the step.
12. A device in accordance with claim 8, wherein the lock plate is
positionable in a substantially flush position with respect to an
upper surface of the elevated deck of the platform when the lock
plate is pivoted to cover the gap.
13. A method for coupling a removable stairway to a platform,
comprising: a) coupling a removable step to an elevated deck of the
platform such that the step extends away from the deck in
cantilever fashion; and b) pivoting a lock plate pivotally coupled
to the step to lock a gap between the step and the elevated deck
such that a flange extending from the lock plate frictionally
engages a side of the platform when the step is attached to the
platform and the lock plate is pivoted to cover the gap.
14. A method in accordance with claim 13, further comprising: a)
positioning a plurality of lower steps coupled to the removable
step below the removable step to form a stairway from a ground
surface to the elevated deck.
15. A method in accordance with claim 13, further comprising: a)
pivoting the lock plate to an unengaged position where the flange
is free from contact with the side of the platform to uncover the
gap; and b) removing the removable step from the elevated deck.
Description
RELATED APPLICATIONS
[0001] This patent application is related to U.S. patent
application Ser. No. 12/098,922 filed Apr. 7, 2008; Ser. No.
12/098,945 filed Apr. 7, 2008; and Ser. No. 12/098,955 filed April
7, 2008 which are herein incorporated by reference in their
entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to portable elevated
platforms such as portable stages, risers, and the like.
[0004] 2. Related Art
[0005] Portable platforms are often used as stages, risers, and the
like. Such platforms are often formed of individual modules that
are assembled at the site the platform is needed. The height of the
platforms is often adjustable so that the platform can be
positioned at a desired height. Sometimes the desired height is too
high for a person to step up onto the platform. In these cases,
steps or a stairs are is needed in order to gain access to the
platform.
[0006] Some portable platform systems use stand alone steps or
stairs that allow access to the platform. These stand alone steps
or stairs are separate stairways that can be pushed next to the
platform. With the ladder next to the platform, people can climb up
the steps on the ladder to gain access to the elevated platform.
Unfortunately, because these stair systems are supported
independently from the platform they can move slightly with respect
to the platform when people are climbing the stairs to enter or
leave the platform. This independent movement can cause noise which
may disrupt an event, as well as an uneasy feeling to people on the
platform and/or the stairs.
[0007] Other portable platform systems attach a stair stringer to
the platform. As used herein, a stair stringer is a plurality of
steps attached to an inclined frame. In some cases, the stair
stringer can be collapsible to more easily store and ship the
stairs. When the stair stringer is attached to the platform, the
steps can extend from the elevated platform to a support surface.
Additionally, such stair stringers can include a sufficient number
of steps to provide comfortable stairway access to the platform,
and can automatically adjust in height with varying platform deck
height.
[0008] Unfortunately, such stairways are often difficult to attach
requiring fasteners such as screws, bolts or the like, which tend
to slow down assembly of the portable platform. Additionally, many
of these attachable stairways have a tendency to move in relation
to the platform as users walk up the stairs to gain access to the
platform. This movement can cause undesirable racking noise and
give unsteady feelings to the users.
SUMMARY OF THE INVENTION
[0009] The inventors of the present invention have recognized that
it would be advantageous to develop a removable stairway for an
elevated platform that can be easily secured to the platform.
Additionally, the inventors of the present invention have
recognized that it would be advantageous to develop a removable
stairway for an elevated platform that can be attached to the
platform without the use of separate fasteners. Additionally, the
inventors of the present invention have recognized that it would be
advantageous to develop a removable stairway for an elevated
platform that can resist separate movement with respect to the
platform when dynamically loaded as a user walks on the steps.
Additionally, the inventors of the present invention have
recognized that it would be advantageous to develop a stairway for
an elevated platform that is adjustable in height in order to match
the height of the elevated platform and that each step in the step
system can automatically adjust in height to a similar height as
the other steps in the stairway.
[0010] The invention provides for a removable stairway device
configured for attachment to a platform. The removable stairway can
include a platform having an elevated deck and a plurality of legs
supporting the deck. A step or step system can be removably
attachable to the platform and extendable from the platform in
cantilever fashion. A gap can be formed between the step and the
elevated deck of the platform when the removable step is attached
to the platform. A lock plate can be pivotally coupled to the step.
The lock plate can pivot to cover the gap between the step and the
elevated deck. A flange can extend from the lock plate and engage a
side of the platform when the step is attached to the platform and
the lock plate is pivoted to cover the gap.
[0011] The present invention also provides a method for coupling a
removable stairway to a platform including coupling a removable
step to an elevated deck of the platform such that the step extends
away from the deck in cantilever fashion. A lock plate can be
pivotally coupled to the step to lock a gap between the step and
the elevated deck such that a flange extending from the lock plate
frictionally engages a side of the platform to safely lock the
stairs in place when the step is attached to the platform and the
lock plate is pivoted to cover the gap.
[0012] Additional features and advantages of the invention will be
apparent from the detailed description which follows, taken in
conjunction with the accompanying drawings, which together
illustrate, by way of example, features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side view of a removable stairway coupled to an
elevated platform in accordance with an embodiment of the present
invention;
[0014] FIG. 2 is a side view of a removable step of the removable
stairway of FIG. 1, shown in a coupleable orientation with respect
to the elevated platform of FIG. 1;
[0015] FIG. 3 is a side view of a removable step of the removable
stairway of FIG. 1, shown in a coupleable orientation with respect
to the elevated platform of FIG. 1;
[0016] FIG. 4 is a side view of a removable step of the removable
stairway of FIG. 1, shown in a coupled orientation with respect to
the elevated platform of FIG. 1;
[0017] FIG. 5 is a side view of a removable step of the removable
stairway of FIG. 1, shown in a coupled orientation with respect to
the elevated platform of FIG. 1 and also showing a lock plate
locking a gap between the removable step and the elevated platform
in accordance with an embodiment of the present invention;
[0018] FIG. 6 is a fragmentary side view of the removable step of
FIG. 2 coupled to the platform of FIG. 1;
[0019] FIG. 7 is a fragmentary perspective view of the removable
step of FIG. 2 shown with a pivotable lock plate hingedly coupled
to the removable step;
[0020] FIG. 8 is a fragmentary perspective view of the removable
step of FIG. 2 shown with the lock plate of FIG. 7 partially
installed into a hinge slot; and
[0021] FIG. 9 is a fragmentary perspective view of the removable
step and lock plate of FIG. 8 shown with the lock plate partially
installed into a hinge slot.
DETAILED DESCRIPTION
[0022] Reference will now be made to the exemplary embodiments
illustrated in the drawings, and specific language will be used
herein to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended. Alterations and further modifications of the inventive
features illustrated herein, and additional applications of the
principles of the inventions as illustrated herein, which would
occur to one skilled in the relevant art and having possession of
this disclosure, are to be considered within the scope of the
invention.
[0023] The embodiments of the present invention described herein
provide generally for a removable stairway for an elevated platform
such as a deck, riser, stage, and the like. The removable stairway
can include a step removably coupleable to the elevated deck of the
platform. A plurality of lower steps can extend downward from the
removable step to a ground surface to form the stairway. The
removable step can include a cover or lock plate pivotally coupled
to the step and pivotal to cover a gap between the step and the
elevated platform and lock the step against the platform. The lock
plate can have a flange extending substantially orthogonally from
the lock plate. The flange can be positioned on the lock plate so
as to engage a side of the platform when the removable step is
coupled to the elevated deck and the lock plate is pivoted to cover
the gap. The flange can frictionally engage the side of the
platform in an interference fit such that an applied force is
required to set or release the lock plate from the locked position.
Advantageously, the removable step can be easily attached to the
platform without any separate fasteners to secure the step to the
platform. Additionally, the lock plate and flange can form a
linkage between the removable step and the side of the platform
that advantageously resists movement of the removable step with
respect to the platform due to dynamic loading on the removable
step as users climb the stairway.
[0024] As illustrated in FIGS. 1-9, a removable stairway device,
indicated generally at 10, attachable to an elevated platform,
indicated generally at 20, is shown in accordance with the present
invention for providing access to the elevated platform. The
platform 20 can include an upper, elevated deck 22 and a plurality
of legs (not shown) that support the deck. The removable stairway
device 10 can include a removable step 50 coupleable to the
platform 20, and a lock plate 70 to lock a gap 90 between the
removable step 50 and the platform 20.
[0025] With respect to the platform 20, the plurality of legs can
be adjustable in length in order to adjust the height of the
elevated deck 22. In one aspect the platform 20 can be a portable
platform such as a portable stage or portable risers as described
in U.S. patent application Ser. No. 12/098,945 filed on Apr. 7,
2008, which is herein incorporated by reference in it's entirety
for all purposes.
[0026] With respect to the removable stairway 10, the removable
step 50 can be removably attachable to the platform 20, and
extendable from the platform in cantilever fashion. The removable
step 50 can be sized and shaped to allow users to stand or walk on
the step as they are climbing the stairway 10. The removable step
50 can be positioned at a spaced apart distance from the side 26 of
the platform 20 in order to form a gap 90 between the step 50 and
the elevated deck 22 of the platform 20.
[0027] The removable step 50 can include a bracket 52 that can fit
within a groove or slot 28 disposed in a side 26 of the platform
20. The bracket 52 can be inserted into the slot 28 by orienting
the step in a vertical orientation, as shown in FIG. 2, and sliding
an upwardly extending lip 54 on the bracket 52 into the slot 28.
The step 50 and bracket 52 can then be rotated, as shown in FIG. 3
to position the step 50 in a substantially horizontal position, as
shown in FIG. 4, with the step 50 extending away from the platform
20 in cantilever fashion. The upwardly extending lip 54 on the
bracket 52 can engage a downwardly extending lip 30 of the slot 28
on the platform 20 when the bracket 52 is disposed in the slot
28.
[0028] In one aspect, the bracket 52 can be separate from the step
50 and can support or carry the removable step, as shown in the
FIGs. In another aspect (not shown), the bracket 52 can be
integrally formed with the removable step 50. In either case, the
bracket 52 and removable step 50 can be configured such that
downward loads, indicated at 100, that may be applied to the
removable step 50 can push the upwardly extending lip 54 of the
bracket 52 against the downwardly extending lip 30 on the slot 28
of the platform 20, as shown in FIG. 5. Thus, in use, when a person
places weight on the removable step 10, the load 100 resulting from
the weight of the person can push the removable step 50 downward.
This downward force 100 can push the upwardly extending lip 54
upward and outward so that the upwardly extending lip can contact
the top 32 of the slot 28 and the downwardly extending lip 30 of
the slot. The contact between the upwardly extending bracket lip 54
and the downwardly extending slot lip 30 can restrict the bracket
20 from moving out of the slot 28 when a downward load is placed on
the removable step 50.
[0029] Additionally, a stair stringer, indicated generally at 110,
can be coupled to the removable step 50 and can extend downward
from the removable step 50 to a ground surface. The stair stringer
110 can include a framework 112 that can support a plurality of
sequential steps 114 with respect to the removable step 50. The
framework 112 can automatically adjust each step to be parallel to
one another. Additionally, the framework 112 can automatically
adjust each step 114 to have a substantially equal height as the
other steps 114 in the stair stringer 110. In this way, the
framework 112 can automatically adjust the steps 114 to match the
height of the elevated platform 20 to which the stair stringer 110
is attached. Together the removable step 50, the framework 112, and
the plurality of lower steps 114 can form the stairway 10.
[0030] Turning to FIGS. 6-9, the lock plate 70 can be pivotally
coupled to the removable step 50. The lock plate 70 can be pivotal
to cover the gap 90 between the removable step 50 and the elevated
deck 22, as shown by dashed lines in FIGS. 1 and 6. The lock plate
70 can be formed of a metal or rigid plastic material that can have
sufficient strength to support dynamic loads from users walking
between the step 50 and the elevated deck 22. For example, in one
aspect, the lock plate 70 can be formed of aluminum and can be
extruded to a desired size. In another aspect, the lock plate 70
can be formed of polyurethane material and molded to the desired
size and shape. Other materials having sufficient strength, as
known in the art, can also be used to form the lock plate 70.
[0031] The lock plate 70 can be a substantially flat plate coupled
to the removable step 50 by a hinge indicated generally at 80. The
hinge 80 can be formed by a cylindrically shaped pivot edge 72 of
the lock plate 70. The cylindrically shaped edge 72 can be disposed
in a mating cylindrically shaped slot 60 on the removable step 50.
The cylindrically shaped slot 60 can have an opening, indicated
generally at 62, extending the length of the cylindrically shaped
slot 60 through which the cylindrically shaped edge 72 of the lock
plate 70 can extend and pivot with respect to the removable step
50. The hinge 80 can extend along and entire length of the
removable step 50. The hinge 80 can be positioned so that when the
lock plate 70 is pivoted to cover the gap 90, the lock plate 70 can
be substantially co-planar with a top surface 58 of the removable
step 50 and a top surface of the elevated deck 38, as best seen in
FIG. 6.
[0032] The lock plate 70 can include a flange 74 that can extend
from the lock plate 70 at an oblique angle with respect to the lock
plate. In one aspect, the flange 74 can extend away from the lock
plate 70 in a direction that is substantially perpendicular to the
lock plate. The flange 74 can be positioned on the lock plate 70 at
a location that allows the flange 74 to engage the side 26 of the
platform 20 when the removable step 50 is attached to the platform
and the lock plate 70 is pivoted to cover the gap 90. The flange 74
can be slightly flexible in order to conform to the position of the
side 26 of the platform 20 with respect to the lock plate 70. In
this way, the flange 70 can be positioned on the lock plate 20 so
as to form an interference fit with the side 26 of the platform 20
when the lock plate 70 is pivoted to cover the gap 90 and the
flange 74 frictionally engages the side of the platform.
[0033] The flange 74 can also include a beveled end 76. The beveled
end 76 can extend towards the pivot end 72 of the lock plate 70.
The beveled end 76 can be sized and shaped to engage the side wall
26 of the platform 20. The beveled end 76 can guide the flange 74
along the side 26 of the platform 20 as the lock plate 70 is
pivoted to cover the gap 90. It will be appreciated that a straight
or butt end on the flange could catch or hang up on the side of the
platform because in order to achieve the interference fit between
the flange 74 and the side 26 of the platform 20, the position of
the flange 74 might slightly overlap the position of the side of
the platform. Thus, in order to allow the flange 74 to engage and
slide along the side 26 of the platform 20, the beveled end 76 can
first contact the side of the platform and flex or bend the flange
to conform to the position of the side of the platform.
[0034] Advantageously, the interference fit between the flange 74
and the side 26 of the platform 20 can restrict inadvertent
movement of the lock plate 70 during loading of the removable step
50. Additionally, the lock plate 70 and flange 74 can maintain the
position of the removable step 50 with respect to the platform 20
when the lock plate 70 is pivoted to cover the gap 90.
Consequently, the interference fit between the flange 70 and the
side 26 of the platform 20 can restrict movement of the removable
step 50 with respect to the platform 20. In this way, the lock
plate 70 and flange 74 can act as a linkage mechanism that can lock
the removable step 50 into place with respect to the platform 20.
Thus, advantageously, the flange 74 can resist rotation of the
removable step 50 due to upward and downward forces applied to the
removable step 50 by users of the stairway 10 when the lock plate
70 is pivoted to cover the gap 90 and the flange 74 engages the
side 26 of the platform 20.
[0035] The present invention also provides a method for coupling a
removable stairway to a platform including coupling a removable
step to an elevated deck of the platform such that the step extends
away from the deck in cantilever fashion. A lock plate can be
pivotally coupled to the step to lock a gap between the step and
the elevated deck such that a flange extending from the lock plate
frictionally engages a side of the platform when the step is
attached to the platform and the lock plate is pivoted to cover the
gap.
[0036] The method can also include positioning a plurality of lower
steps coupled to the removable step below the removable step to
form a stairway from a ground surface to the elevated deck.
[0037] Additionally, the method can also include pivoting the lock
plate to an unengaged position where the flange is free from
contact with the side of the platform to uncover the gap. The
removable step can then be removed from the elevated deck.
[0038] It is to be understood that the above-referenced
arrangements are only illustrative of the application for the
principles of the present invention. Numerous modifications and
alternative arrangements can be devised without departing from the
spirit and scope of the present invention. While the present
invention has been shown in the drawings and fully described above
with particularity and detail in connection with what is presently
deemed to be the most practical and preferred embodiment(s) of the
invention, it will be apparent to those of ordinary skill in the
art that numerous modifications can be made without departing from
the principles and concepts of the invention as set forth
herein.
* * * * *