Note: Descriptions are shown in the official language in which they were submitted.
CA 02717126 2010-10-07
MAST, LADDER, PLATFORM (MLP) ASSEMBLY AND METHOD
BACKGROUND
FIELD
[0001] The present invention relates to an assembly for providing
support and access to railroad or traffic signals.
RELATED ART
[0002] Mast ladder platform (MLP) assemblies are used to mount lights
such as railroad signals at a desired height off of the ground and to provide
repair and maintenance access to these lights. MLP assemblies typically
comprise one or two platforms and two to four light fixtures attached to a
pole
or mast. Two light fixtures facing opposite directions are often mounted near
a top end of the mast and another light fixture is mounted lower, in a mid-
section of the mast facing the same direction as one of the light fixtures
near
the top end of the mast. A platform may extend from the mast proximate the
light fixtures at the top end of the mast and/or a platform extending from the
mid-section of the mast proximate its light fixture. A ladder may be fixed to
the platforms to provide access thereto.
[0003] MLP assemblies are typically shipped on flatbed trucks with
ladders and masts banded together and platforms welded together or crated
in pieces and assembled at the site. Shipping of the MLP assemblies in this
manner can be difficult because the different size crates, platforms, and
poles
limit the ability to stack the various components. Thus, only a few MLP
assemblies may be shipped on a single flatbed truck.
[0004] Furthermore, once these MLP assemblies reach an installation
site, they typically must be assembled on the ground by a crew of individuals.
Weather conditions can greatly affect the ease or difficulty of assembly. For
example, the platforms are typically secured to the masts with two U-bolts or
straps. If the ground is snowy and/or muddy, these U-bolts or straps are
difficult to attach to the masts because the masts may be laying in the snow
or
mud.
[0005] Moreover, the size and weight of the welded platforms typically
necessitates several individuals to maneuver them onto the mast for
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assembly. The MLP assembly must then be lifted from the ground to an
upright vertical position with a crane, and the masts have a tendency to roll
relative to the size of a base of the MLP assembly during this lifting
process.
This rolling motion of such a large assembly can be dangerous to individuals
installing the MLP assembly and standing nearby.
[0006] The rolling motion may be due in part to the ladder attached to
the MLP assembly. The ladder is typically attached directly to the platforms
prior to lifting the MLP assembly. However, in order to secure the ladder at
the bottom thereof, the ladder is made longer than the mast and is attached to
a ladder foundation buried in the ground. Because the ladder extends lower
than the base of the MLP assembly, it is prone to bending under the weight of
the MLP assembly during lifting to its vertical orientation. Furthermore,
digging a hole for the ladder foundation takes additional time and labor.
[0007] The railroad signals attached to the MLP assemblies each may
have a housing with access doors on the back. Since the doors are
generically configured to only swing in one direction, at least one of the
doors
often collides with a top rail of its corresponding platform when opened. To
solve this problem, it is know to remove a portion of the top rail of the
platform
to allow the access doors to open freely, but removal of a section of the top
rail structurally weakens the railing and the platform.
[0008] Accordingly there is a need for an MLP assembly that
overcomes the limitations of the prior art.
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SUMMARY
[0009] Embodiments of the present invention solve the above-
mentioned problems and provide a distinct advance in the art of mast ladder
platform (MLP) assemblies for support and maintenance of a railroad signal.
An MLP assembly constructed in accordance with an embodiment of the
invention may comprise a mast, one or more platform assemblies attached to
the mast, and one or more ladders attached to the mast and/or the platform
assemblies. The MLP assembly may also comprise a lower ladder support, a
middle ladder support, and/or a plurality of F-brackets for attaching the
ladders to the mast and/or the platform assemblies at a non-0 angle and a
plurality of stacking brackets proximate a top end and a bottom end of the
mast and configured to allow a plurality of MLP assemblies to be stacked one
on top of another for transport.
[0010] The platform assemblies may each comprise a platform, a top
rail, and a middle rail, each pivotable relative to the mast between a folded
configuration and an unfolded configuration. Lower and/or middle ladder
supports may also be pivotable between the folded configuration and the
unfolded configuration. The MLP assembly may be transported in the folded
configuration and then unfolded at the installation site. The platform, top
rail,
middle rail, and the ladder supports may have bolts added thereto in the
unfolded configuration to prevent them from rotating back to the folded
configuration. Furthermore, vertical supports may be bolted to the platform,
top rail, and middle rail in the unfolded configuration.
[0011] At an installation site, the MLP assembly may rest on at least
two of the stacking brackets in a horizontal orientation while the platform,
top
rail, middle rail, and ladder supports are unfolded. Then the MLP assembly
may be reoriented from the horizontal orientation to a vertical orientation in
which it is fixed to the ground and/or an installation surface.
[0012] This summary is provided to introduce a selection of concepts in
a simplified form that are further described below in the detailed
description.
This summary is not intended to identify key features or essential features of
the claimed subject matter, nor is it intended to be used to limit the scope
of
the claimed subject matter. Other aspects and advantages of the present
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invention will be apparent from the following detailed description of the
preferred embodiments and the accompanying drawing figures.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments of the present invention are described in detail
below with reference to the attached drawing figures, wherein:
[0014] FIG. 1 is a front perspective view of an MLP assembly
constructed in accordance with an embodiment of the present invention and
installed at an installation site in an unfolded configuration and in a
vertical
orientation;
[0015] FIG. 2 is a rear perspective view of the MLP assembly of Fig. 1;
[0016] FIG. 3 is a front perspective view of an alternative embodiment
of the MLP assembly in which a middle platform assembly is replaced with a
middle ladder support;
[0017] FIG. 4 is a fragmentary rear perspective view of the MLP of Fig.
3;
[0018] FIG. 5 is a perspective view of a mast of the MLP assembly of
Fig. 1;
[0019] FIG. 6 is a front perspective view of a ladder assembly of the
MLP assembly of Fig. 1;
[0020] FIG. 7 is a rear perspective view of the ladder assembly of Fig.
6;
[0021] FIG. 8 is a perspective view of the ladder assembly of Fig. 1 in a
folded configuration and resting in a horizontal orientation;
[0022] FIG. 9 is a perspective view of a plurality of stacked MLP
assemblies, each similar to the MLP assembly of Fig. 1;
[0023] FIG. 10 is a front top perspective view of the MLP assembly of
Fig. 8 with a lower ladder support and a platform of the middle platform
assembly each fixed in their respective unfolded configurations;
[0024] FIG. 11 is a fragmentary front bottom perspective view of the
MLP assembly of Fig. 10;
[0025] FIG. 12 is a fragmentary front top perspective view of the
MLP assembly of Fig. 10 with a platform of an upper platform assembly also
fixed in its unfolded configuration;
[0026] FIG. 13 is a fragmentary front bottom perspective view of the
MLP assembly of Fig. 10 with a top rail of the middle platform assembly fixed
in its unfolded configuration;
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[0027] FIG. 14 is a fragmentary front top perspective view of the MLP
assembly of Fig. 13 with a middle rail of the middle platform assembly fixed
in
its unfolded configuration; and
[0028] FIG. 15 is a fragmentary front top perspective view of the MLP
assembly of Fig. 14 illustrating one vertical support attached to the top
rail,
middle rail, and platform of the middle platform assembly and one vertical
support still unattached from the middle platform assembly.
[0029] The drawing figures do not limit the present invention to the
specific embodiments disclosed and described herein. The drawings are not
necessarily to scale, emphasis instead being placed upon clearly illustrating
the principles of the invention.
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DETAILED DESCRIPTION
[0030] The following detailed description of the invention references the
accompanying drawings that illustrate specific embodiments in which the
invention can be practiced. The embodiments are intended to describe
aspects of the invention in sufficient detail to enable those skilled in the
art to
practice the invention. Other embodiments can be utilized and changes can
be made without departing from the scope of the present invention. The
following detailed description is, therefore, not to be taken in a limiting
sense.
The scope of the present invention is defined only by the appended claims,
along with the full scope of equivalents to which such claims are entitled.
[0031] In this description, references to "one embodiment", "an
embodiment", or "embodiments" mean that the feature or features being
referred to are included in at least one embodiment of the technology.
Separate references to "one embodiment", "an embodiment", or
"embodiments" in this description do not necessarily refer to the same
embodiment and are also not mutually exclusive unless so stated and/or
except as will be readily apparent to those skilled in the art from the
description. For example, a feature, structure, act, etc. described in one
embodiment may also be included in other embodiments, but is not
necessarily included. Thus, the present technology can include a variety of
combinations and/or integrations of the embodiments described herein.
[0032] Figs. 1-3 illustrate exemplary embodiments of a mast ladder
platform (MLP) assembly 10 configured for supporting and providing
maintenance access to one or more lights (not shown), such as railroad
signals. The MPL assembly 10 broadly comprises a mast 12, one or more
platform assemblies 14,16 attached to the mast 12, and at least one ladder
18,20 attached to the mast 12 and/or the platform assemblies 14,16. The
MPL assembly 10 may further comprise a base 22 for fixing the mast 12
relative to the ground and one or more stacking brackets 24,26,28,30 for
stacked transportation of a plurality of MPL assemblies, as further
illustrated
in Figs. 8-14. Some embodiments of the MLP assembly 10 may also
comprise a plurality of attachment components, ladder supports, and electrical
housing components for housing various electrical circuits and/or wiring to be
attached to the one or more lights, as later described herein.
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[0033] As illustrated in Fig. 5, the mast 12 may be a hollow elongated
tube or pipe and may be made out of steel or any other suitable metal or hard,
durable material. The mast may be welded or integrally formed with a
plurality of the attachment components configured for supporting the platform
assemblies 14,16 and/or the ladders 18,20. In some embodiments of the
invention, the attachment components and/or various markings on the mast
may include markings, registry features, or other guides to where various
components should be attached. A plurality of holes 32 may be formed in the
mast 12 through which electrical wires may extend.
[0034] As illustrated in Figs. 6-7, the platform assemblies 14,16 may be
made from any combination of steel, other suitable metals, and other hard,
durable materials known in the art. The platform assemblies 14,16 may
include a middle platform assembly 14 and an upper platform assembly 16.
Each of the platform assemblies 14,16 may comprise a platform 34, a top rail
36, a middle rail 38, and one or more vertical supports 40.
[0035] The platform 34 may comprise a plurality of platform rails
42,44,46,48 which may be made of hollow tubes having a square,
rectangular, circular, triangular, or any other cross-sectional shape. For
example, four elongated platform tubes having a hollow, square-shaped
cross-section may be arranged into a square or rectangle to form a periphery
of the platform 34. In this configuration, there may be a front platform rail
42,
a back platform rail 44, and two side platform rails 46,48. The platform rails
42-48 may be bolted together, welded together, or integrally formed as a
single monolithic piece.
[0036] In an alternative embodiment, the platform rails may be angle or
angle rails. Angle or angle rail, as used herein, may be defined as an
elongated rail with an L-shaped cross-section or two elongated straps forming
right degree angles with each other down the length thereof. Straps or strips,
as used herein, may be defined as rigid, elongated, substantially flat
components which may be substantially rectangular. Angle, angle rails,
straps, and strips as used herein may be made of steel, metal, or any other
rigid, durable material.
[0037] The platform 34 may also comprise a platform grate 50
positioned between and attached to the platform rails 42-48 and arranged in
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any configuration or pattern required to allow a person to stand thereon. The
platform grate 50 may be bolted to, welded to, or integrally formed with the
platform rails 42-48.
[0038] The platform 34 may further comprise pivotable straps 52,
platform support angles 54, and vertical support attachment straps 56. The
pivotable straps 52 may be substantially flat, rigid steel straps bolted to,
welded to, or otherwise integrally formed with another component of the
platform 34, such as the platform rails 42-48. The pivotable straps 52 may be
fixedly attached to and extend from the back platform rail 44 at a
substantially
perpendicular angle relative to the length of the platform rail 44. In some
embodiments of the MLP assembly 10, two pivotable straps 52 spaced apart
from each other and perpendicular with each other may be provided. The
pivotable straps 52 of the platform 34 may also each have a notch having a
right angle formed therein, such that one edge formed by the notch can be
welded to a first side of the back platform rail 44, and the other edge formed
by the notch can be welded to a second side of the back platform rail 44 that
is adjacent to the first side, as illustrated in Fig. 7.
[0039] The pivotable straps 52 may have holes formed therethrough
such that a bolt or any other mechanical attachment may extend therethrough
to fixedly and/or pivotally attach the pivotable straps 52 to the mast 12. For
example, the pivotable straps 52 may rotate about a bolt in order to actuate
the platform 34 from a folded position to an unfolded position and vice versa.
In the folded position, the platform 34 is substantially parallel with an axis
of
the mast 12, and in the unfolded position, the platform 34 is substantially
perpendicular with the axis of the mast 12, as later described herein.
[0040] The platform support angles 54 may extend across the platform
grate 50 and/or may extend from the front platform rail 42 to the back
platform
rail 44 and may be arranged substantially parallel with the side platform
rails
46,48. The platform support angles 54 may be bolted to, welded to, and/or
integrally formed with one or more of the platform rails 42-48 and the
platform
grate 50. The platform support angles 54 may be made of angles or angle
rails and may provide additional support underneath the platform grate 50
when an individual is standing thereon. In some embodiments of the MLP
assembly 10, there may be two or more platform support angles 54
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substantially equally spaced apart from each other or spaced in any manner
desired to provide a desired load distribution. At least a portion of the
platform support angles 54 may have holes formed therein for attachment of
ladder supports, as later described herein.
[0041] The vertical support attachment straps 56 of the platform 34
may be fixed to the side platform rails 46,48 and may comprise one or more
holes formed therethrough for attachment to at least one of the vertical
supports 40. The holes may be sized and configured to receive bolts
therethrough. The vertical support attachment straps 56 may be bolted to,
welded to, or otherwise integrally formed with the side platform rails 46,48.
Alternatively, one or more vertical support attachment holes may be formed
directly into at least one of the side platform rails 46,48 and configured for
providing attachment to at least one of the vertical supports 40.
[0042] The top rail 36 may be made of hollow tubes, which may be
square, rectangular, circular, triangular, or any cross-sectional shape. The
top rail 36 may have an outward-curving portion 58 and an inward-curving
portion 60. The outward-curving portion 58 of the top rail 36 may be curved or
angled outward and substantially away from an individual standing on the
platform 34. The inward-curved portion 60 of the top rail 36 may be curved or
angled inwards to provide clearance for a light box or signal box door (not
shown) to open in a direction toward the top rail 36. The top rail 36 may
extend approximately 1800 around an individual on the platform 34, with a
safety chain 62 attachable between two ends of the top rail 36.
[0043] The safety chain 62 may be a chain, rope, door, pivotable gate,
or any other apparatus configured to, along with the top rail's outward- and
inward-curving portions 58,60, cooperatively form a 360 boundary around an
individual standing on the platform 34. Furthermore, the top rail 36 may
comprise safety chain tabs 64 having holes formed therein through which the
safety chain may be linked. The safety chain tabs 64 may be bolted to,
welded to, or integrally formed with the top rail 36.
[0044] The top rail 36 may also comprise or be attached to vertical
support attachment straps 66, which may have holes formed therethrough for
attachment to the vertical supports 40. The holes in the vertical support
attachment straps 66 on the top rail 36 may be laterally and/or vertically
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aligned with the holes formed in the vertical support attachment straps 56 of
the platform 34. The vertical support attachment straps 66 may each be
bolted to, welded to, or integrally formed with the outward-curving portion 58
of the top rail 36. Alternatively, one or more vertical support attachment
holes
may be formed directly into the outward-curving portion 58 of the top rail 36
and configured for providing attachment to at least one of the vertical
supports
40. The holes may be sized and configured to receive bolts therethrough.
[0045] The top rail 36 may also comprise or be fixedly attached to
pivotable straps 68 which may have holes formed therethrough for attachment
to the mast 12. The pivotable straps 68 of the top rail 36 may be bolted to,
welded to, or otherwise integrally formed with the top rail 36. The pivotable
straps 68 of the top rail 36 may be laterally aligned with the pivotable
straps
52 of the platform 34. The pivotable straps 68 of the top rail 36 may comprise
a pair of pivotable straps which may be identical in length or may have
differing lengths from each other. For example, making one of the pivotable
straps 68 of the top rail 36 shorter than the other may allow the top rail to
be
pivoted about a bolt to the folded position without interfering with or
colliding
with other components.
[0046] The pivotable straps 68 of the top rail 36 may require at least
two attachment holes or alternatively only one attachment hole formed
therethrough. The pivotable straps 68 of the top rail 36 may also each have a
notch having a right angle formed therein, such that one edge formed by the
notch can be welded to a first side of the hollow top rail 36, and the other
edge formed by the notch can be welded to a second side of the hollow top
rail 36 that is adjacent to the first side, as illustrated in Fig. 7.
[0047] The middle rail 38 of at least one of the platform assemblies
14,16 may be made of hollow tubes, which may be square, rectangular,
circular, triangular, or any cross-sectional shape. The middle rail 38 may be
curved outward continuously or at given length intervals to extend
approximately 180 around an individual standing on the platform 34. The
middle rail 38 may further comprise or be fixedly attached to at least one
mast
attachment tab 72, which may have at least one hole formed therethrough for
pivotable or fixed attachment to the mast 12, as described below. The middle
rail 38 may be bolted to, welded to, or integrally formed with the mast
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attachment tab 72. The middle rail 38 may also comprise or be fixedly
attached to one or more vertical support attachment plates 74. The vertical
support attachment plates 74 of the middle rail 38 may be configured to attach
to one of the vertical supports 40 at a point between the platform 34 and the
top rail 36.
[0048] The vertical supports 40 may each comprise a primary support
rail 76, an upper vertical support plate 78, a lower vertical support plate
80,
and a middle rail attachment tab 82. The primary support rail 76 may be
made of hollow tubes, which may be square, rectangular, circular, triangular,
or any cross-sectional shape. The lower and upper vertical support plates
78,80 may be bolted to, welded to, or integrally formed with the primary
support rail 76 proximate opposite ends thereof. The lower and upper vertical
support plates 78,80 may each comprise two holes formed therethrough such
that bolts or other mechanical attachments may extend therethrough to attach
the vertical supports 40 to the vertical support attachment straps 56 of the
platform 34 and the vertical support attachment straps 66 of the top rail 36,
respectively. The middle rail attachment tab 82 of each of the vertical
supports 40 may have at least one hole formed therethrough, configured to
allow bolts or other mechanical attachments to extend therethrough to be
couple with one of the vertical support attachment plates 74 of the middle
rail
38.
[0049] The ladders 18,20 may each comprise a plurality of rungs 84
and two rung supports 86,88 attached at opposite ends of each of the rungs
84, such that the rungs are spaced apart and parallel with each other. The
ladders 18,20 may be two bolted together to form a single ladder. The
ladders 18,20 may be attached via various mechanical attachments, as
described below, to the mast 12 at an angle between 0 and 90 . Specifically,
the ladders 18,20 may be fixed to the mast 12 at an angle between 2 and
. For example, the ladders may be fixed to the mast 12 at an
approximately 5 angle, as illustrated in Figs. 1-3. In some embodiments of
the invention, when the mast 12 is substantially vertical in relationship with
the
ground and the ladders 18,20 are mounted to the mast 12, a bottom end of
the ladders 18,20 does not extend any lower than the base 22 of the MLP
assembly 10.
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[0050] In some embodiments of the MLP assembly 10, an optional
bottom ladder support (not shown) may be bolted proximate a bottom-most
rung of the ladders 18,20 relative to the ground and may have a portion
thereof configured to be buried in the ground when the mast 12 is vertically
oriented and the base 22 is fixed relative to the ground. This ladder
configuration is advantageous because it allows the base to make contact
with the ground first when the MLP assembly 10 is raised from a horizontal
orientation to a vertical orientation, as opposed to a ladder contacting the
ground first as the MLP assembly 10 is tipped up from its horizontal to its
vertical orientation.
[0051] The base 22 may comprise a base plate 90, mast-supporting
gussets 92, and a temporary base frame 94, as illustrated in Fig. 8. The base
plate 90 may be substantially square, circular, rectangular, triangular, or
any
shape desired. In one embodiment of the base 22, the base plate 90 is
square with four rounded corners. The base plate 90 may be welded to,
bolted to, and/or integrally formed with the mast 12 at or proximate a bottom
end thereof. For example, an approximately mast-sized hole may be formed
through a center of the base plate 90 and the mast 12 may be welded to the
base plate 90 at the periphery of the mast-sized hole. Furthermore, fastening
holes or slots may be formed through the base plate 90 such that mechanical
fasteners may be inserted therethrough for securing the base 90 to the
ground or another mounting surface.
[0052] The mast-supporting gussets 92 may be welded to, bolted to,
and/or integrally formed with the base plate 90 and/or the mast 12. The mast-
supporting gussets 92 may be substantially triangular in shape, with a first
edge attached to the base plate 90 and a second edge attached to the mast
12. In some embodiments, the gussets form right triangles, and a tangent
edge of each mast-supporting gusset 92 faces away from the base plate 90
and the mast 12. For example, there may be 4 mast-supporting gussets 92
arranged in 90 angles relative to each other around the mast 12 and 90
angles relative to base plate 90.
[0053] The temporary base frame 94 may be configured to provide
efficient transporting and re-orienting of the MLP assembly 10, but may be
removed before the base plate 90 is fixedly attached to the ground or any
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other mounting surface. As illustrated in Fig. 8, the temporary base frame 94
may comprise at least four elongated temporary base frame pieces
96,98,100,102, at least one diagonal support strip 104, and at least two
rocker
straps 106,108. The temporary base frame pieces 96-102 may be attached
together in a square or rectangular configuration in such a manner as to
provide a wider base for the MLP assembly 10 than the base plate 90
provides. This is particularly useful when the MLP assembly 10 is re-
orientated from the horizontal to the vertical orientation. In some
embodiments of the MLP assembly 10, the diagonal support strip 104 is
attached to at least two of the temporary base frame pieces 96-102 and
mechanically attached to the base plate 90 in one or more locations.
[0054] The rocker straps 106,108 may be configured to allow the MLP
assembly 10 to rock or pivot thereon when re-oriented from the horizontal to
the vertical orientation. The rocker straps 106,108 may be substantially V-
shaped with a first portion 110 extending at a 90 angle from at least one of
the temporary base frame pieces 96-102, a second portion 112 forming a
less-than-900 angle with the first portion, and a curved corner portion 114 or
radiused corner portion extending between the first and second portions
110,112. When the mast 12 is raised from a substantially horizontal
orientation up to a vertical orientation relative to the ground, the mast 12
may
rock or pivot on the curved or radiused corner portion 114 of the rocker
straps
106,108 to gradually guide the mast 12 to its upright horizontal orientation.
In
other embodiments, the rocker straps may be substantially J-shaped, with the
first portion 110 being shorter than the second portion 112. The curved or
radiused corner portion 114 may have any radius desired. The rocker straps
106,108 may be spaced apart at or proximate to opposing ends of one of the
temporary base frame pieces 96-102.
[0055] The temporary base frame pieces 96,98 may also serve as the
stacking brackets 24,26 of the MLP assembly 10. For example, a first
temporary base frame piece 96 may also be a first base stacking bracket 24
and a second temporary base frame piece 98 may also be a second base
stacking bracket 26. The other two temporary base frame pieces 100,102
may be substantially rigid straps each have a first end with a notch formed
therein for mating with and/or being welded to the first stacking bracket 24,
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and a second end extending past a point at which ends of the second
stacking bracket 26 are welded to the temporary base frame pieces 100,102.
In some embodiments of the invention, the second ends of the temporary
base frame pieces 100,102 may angle away from each other to help orient the
second stacking bracket 26 of another MLP assembly being stacked thereon.
[0056] The stacking brackets 24-30, as illustrated in Figs. 8-9 may also
comprise a first top stacking bracket 28 and a second top stacking bracket 30.
One or more of the stacking brackets 24-30 may further comprise and/or
attach to bracket extensions 116 extending between the stacking brackets 24-
30 and the mast 12 to create a desired amount of separation between stacked
MLP assemblies.
[0057] The first base stacking bracket 24 and the first top stacking
bracket 28 may each comprise elongated, substantially V-shaped channels
angled away from a center axis of the mast 12. The second base stacking
bracket 26 and the second top stacking bracket 30 may each comprise
elongated, substantially V-shaped channels angled toward the center axis of
the mast 12. The first base stacking bracket 24 and the second base stacking
bracket 26 may be positioned substantially perpendicular with the center axis
of the mast. The first top stacking bracket 28 and the second top stacking
bracket 30 may be positioned substantially parallel with the center axis of
the
mast.
[0058] The bracket extensions 116 attached to the first and second top
stacking brackets 28,30 may extend between the first top stacking bracket 28
and the mast 12 and between the second top stacking bracket 30 and the
mast 12, respectively. For example, one end of the bracket extensions 116
may be bolted to, welded to, and/or integrally formed with the stacking
brackets 28,30 and an opposing end of the bracket extensions 116 may be
bolted to, welded to, or integrally formed with bracket tabs 117 extending
outward from the mast 12 proximate a top end of the mast 12. The bracket
tabs 117 may be bolted to, welded to, or integrally formed with the mast 12.
Alternatively, the bracket tabs 117 may be formed together with each other as
a single integral piece, forming an integral top bracket tab (not shown) which
may extend through two radially-aligned openings or holes formed proximate
a top end of the mast 12. Then the integral top bracket tab may be welded
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thereto and the first and second top brackets 28,30 and/or the bracket
extensions 116 may be welded to ends of the integral top bracket tab.
[0059] Various attachment components may be integrally formed to,
welded to, or bolted to the mast 12 to attach the ladders 18,20 and the
platform assemblies 14,16 thereto. For example, as illustrated in Figs. 10-12,
attachment components for attaching the platform assemblies 14,16 to the
mast 12 may include platform-mast attachment plates 118,120, top rail-mast
attachment plates 122,124, and middle rail-mast attachment tabs 126,128,
each of which may be bolted to, welded to, or integrally formed with the mast
12.
[0060] In some embodiments of the invention, the mast 12 may have
mast attachment plates 125 welded or integrally formed thereto and extending
at a substantially 90 angle relative to the center axis of the mast 12, as
illustrated in Fig. 5. The mast attachment plates 125 may have holes formed
therethrough such that the platform-mast attachment plates 118,120 and the
top rail-mast attachment plates 122,124 may mate with and be bolted to the
mast attachment plates 125. The mast attachment plates 125 may each be
substantially square or rectangular with an arch or half-circle-shaped notch
cut into one side edge thereof for mating with the mast 12 and be welded
thereto.
[0061] The platform-mast attachment plates 118,120 and the top rail-
mast attachment plates 122,124 may also each be substantially square or
rectangular with an arch or half-circle-shaped notch cut into one side edge
thereof for mating with the mast 12. The plates 118-124 may each be
substantially perpendicular relative to the center axis of the mast 12. Each
of
the plates 118-124 may comprise or be attached to first and second mast
attachment straps 130,132. The first and second mast attachment straps
130,132 may be bolted to, welded to, or integrally formed with each of the
plates 118-124 on opposing edges thereof.
[0062] One or two pairs of the first and second mast attachment straps
130,132 attached to the platform-mast attachment plates 118,120 may have
one or more holes formed therethrough for attachment to the pivotable straps
52 of the platform 34. One or two other pairs of the first and second mast
attachment straps 130,132 attached to the top rail-mast attachment plates
16
CA 02717126 2010-10-07
122,124 may have one or more holes formed therethrough for attachment to
the pivotable straps 68 of the top rail 36. For example, the holes may be
sized to allow bolts to extend therethrough for attachment.
[0063] The platform-mast attachment plates 118,120 may also
comprise or be attached to one or more pivot limiting tabs 134. The pivot
limiting tabs 134 may be bolted to, welded to, or integrally formed with the
platform-mast attachment plates 118,120 and/or their corresponding first and
second mast attachment straps 130,132, and may be positioned to impede a
rotational path of the pivotable straps 52 of the platform 34. Specifically,
the
pivot limiting tabs 134 may prevent the platform 34 from unfolding greater
than or rotating greater than 90 relative to the center axis of the mast 12.
[0064] The middle rail-mast attachment tabs 126,128 may each be
bolted to, welded to, or integrally formed with the mast 12, protruding in a
radial direction therefrom. Furthermore, the middle rail-mast attachment tabs
126,128 may each have a small length oriented substantially parallel with the
center axis of the mast 12. The middle rail-mast attachment tabs 126,128
may each have one or two holes formed therein such that a mechanical
fastener may extend therethrough to fixedly and/or rotatably couple the middle
rail-mast attachment tabs 126,128 with the mast attachment tabs 72 of the
middle rails 38.
[0065] The MLP assembly 10 may include a plurality of components for
supporting the ladders 18,20. Specifically, the MPL assembly 10 may
comprise one or more F-brackets 136 each having a first elongated rail 138
and two parallel, rigid attachment strips 140,142 bolted to, welded to, or
integrally formed with the first elongated rail 138. The first elongated rail
138
may be an angle rail. The two attachment strips 140,142 may be attached
perpendicular to the first elongated rail 138 and may have one or more holes
formed therein. The attachment strips 140,142 may be spaced apart by a
distance approximately equal to a width of the ladders 18,20, such that
mechanical attachments may be inserted through the attachment strips
140,142 and the ladder rung supports 86,88 to fixedly couple the F-brackets
136 and the ladders 18,20 together.
[0066] The first elongated rail 138 of at least some of the F-brackets
136 may be bolted to, welded to, or integrally formed with the platform
support
17
CA 02717126 2010-10-07
angles 54 of the platform 34. For example, the first elongated rail 138 of one
of the F-brackets 136 may be fixed to a first one of the platform support
angles 54 on the middle platform assembly 14 and the first elongated rail 138
of another one of the F-brackets 136 may be fixed to a second one of the
platform support angles 54 on the upper platform assembly 16. The first one
of the platform support angles 54 and the second one of the platform support
angles 54 may be purposely positioned in vertical misalignment to allow the
ladders 18,20 to be mounted at a non-0 angle, such as a 50 angle, relative to
the center axis of the mast 12. For example; the first one of the platform
support angles 54 may be more closely located to a center point of the
platform 34 than the second one of the platform angles 54. In some
embodiments of the invention, the top rail 36 of the upper platform assembly
16 and/or one of the upper vertical support plates 80 thereof may be attached
to one of the F-brackets 136 to provide additional support proximate a top end
of the ladder 18,20.
[0067] The MLP assembly 10 may also comprise a lower ladder
support 145 and/or a middle ladder support 147 which may be attached
directly to the mast 12 via a plurality of attachment components. The lower
ladder support 145 may be attached to the mast 12 proximate the base. In
some embodiments of the invention, as illustrated in Figs. 3-4, the middle
platform assembly 14 may be omitted and replaced with the middle ladder
support 147 in a configuration similar to that described below for the lower
ladder support 145.
[0068] The lower ladder support 145, and/or the middle ladder support
147, may each comprise a first elongated channel 139 and two parallel, rigid
attachment strips 141,143 bolted to, welded to, or integrally formed with the
first elongated channel 139. The first elongated channel 139 may be an
elongated rail having three adjacent sides arranged at right degree angles
relative to each other. The two attachment strips 141,143 may be attached
perpendicular to the first elongated channel 139 and may have one or more
holes formed therein. The attachment strips 141,143 may be spaced apart by
a distance approximately equal to a width of the ladders 18,20, such that
mechanical attachments may be inserted through the attachment strips
141,143 and the ladder rung supports 86,88 to fixedly couple the lower ladder
18
CA 02717126 2010-10-07
support 145 and the ladders 18,20 and/or the middle ladder support 147 and
the ladders 18,20.
[0069] The lower ladder support 145, and/or the middle ladder support
147 may also each comprise a second elongated channel 144 attached
perpendicularly relative to the first elongated channel 139. The second
elongated channel 144 may also comprise or be welded to a first mast
attachment plate 146 and a second mast attachment plate 148 at opposing
ends of the second elongated channel 144. The first and second mast
attachment plates 146,148 may both comprise one or more holes therein and
may be pivotally and/or fixedly attached relative to the mast 12 via bolts or
other mechanical attachments. The first elongated channel 139 may be
welded or attached to the second elongated channel 144 at different locations
for the middle ladder support 147 than the lower ladder support 145, as
illustrated in Figs. 3-4. This allows these ladder supports 145,147 to extend
at
different distances to create a non-0 tilt of the ladders 18,20. For example,
the lower ladder support 145 may have an end of the first elongated channel
139 welded directly to a side of the second elongated channel 144 between
its opposing ends at a perpendicular angle, while the middle ladder support
147 in Figs. 3-4 may have a side of the first elongated channel 139 welded
directly to an outer face of the first mast attachment plate 146.
[0070] A ladder support attachment plate 150 may be bolted to, welded
to, or integrally formed with the mast 12. For example, the ladder support
attachment plate 150 may have holes formed therethrough to be bolted to one
of the welded mast attachment plates 125 extending perpendicularly from the
mast 12. The ladder support attachment plate 150 may have an arched or
circular notch formed therein, similar to the platform-mast attachment plates
118,120 and the top rail-mast attachment plates 122,124. Furthermore, a first
ladder support plate 152 and a second ladder support plate 154 may be
bolted to, welded to, or integrally formed with the ladder support attachment
plate 150.
[0071] The first mast attachment plate 146 may be fixedly and/or
pivotally bolted to the first ladder support plate 152 and the second mast
attachment plate 148 may be fixedly and/or pivotally bolted to the second
ladder support plate 154. In one embodiment of the invention, both the first
19
CA 02717126 2010-10-07
mast attachment plate 146 and the first ladder support plate 152 may have
three holes spaced in a substantially triangular configuration through which
bolts or other mechanical attachments may extend. The second mast
attachment plate 148 and the second ladder support plate 154 may each have
at least one hole through which bolts or other mechanical attachments may
extend. In some embodiments of the invention, at least a portion of both the
second mast attachment plate 148 and the second ladder support plate 154
may be positioned closer to the mast 12 than either the first mast attachment
plate 146 or the first ladder support plate 152.
[0072] The lengths of the first and second mast attachment plates
146,148 may be greater than lengths of the first and second ladder support
plates 152,154 respectively, such that the added length of the mast
attachment plates 146,148 may provide surfaces to which the second
elongated channel 144 may be welded or otherwise attached. Having shorter
lengths for the first and second ladder support plates 152,154 also provides
clearance for the second elongated channel 144 when the lower ladder
support 145 and/or the middle ladder support 147 are actuated from a folded
configuration to an unfolded configuration.
[0073] In some embodiments of the invention, the mast 12 may have at
least one retaining tab 156 bolted to, welded to, or integrally formed with
the
mast 12 and configured for securing the lower ladder support 145 in a folded
configuration. For example, the retaining tab 156 may extend perpendicular
to the central axis of the mast 12 and may comprise one or more holes
formed therethough. When the lower ladder support 145 is folded or pivoted
toward the mast 12, at least one of its two attachment strips 140,142 may be
attached to the retaining tab 156 via one or more bolts or other mechanical
attachments. Similarly, the middle ladder support 145 may be mechanically
attached to one of the mast attachment plates 125 in its folded configuration
and then unattached therefrom to be placed in its unfolded configuration.
[0074] As mentioned above, the MPL assembly 10 may also comprise
various electrical housing components, as illustrated in Figs. 1-3, for
housing
various electrical circuits and/or wiring to be attached to the one or more
lights. For example, the MLP assembly 10 may comprise an electrical box
158, wire conduits 160, and a signal box (now shown). The electrical box 158
CA 02717126 2010-10-07
may be welded and/or mechanically joined with the mast 12 proximate the
base 22 thereof and may allow for connection to an external electrical source.
Wires may extend from the electrical box 158 through one of the plurality of
holes 32 formed in the mast 12 and may then be threaded through the wire
conduits 160.
[0075] The wire conduits 160 may have an open end formed integrally
to or welded to the mast 12 at one of the holes 32 formed in the mast 12 such
that wires may extend from the electrical box 158 or signal box through at
least a portion of the mast 12, then out of the mast 12 directly into the wire
conduits 160. The wires extending through the wire conduits 160 may enter
the signal box to be electrically coupled to wires or electrical components
therein. For example, the wires extending out of the wire conduits 160 may
attach to one or more lights in the signal box. Any openings or holes 32 of
the
MLP assembly 10 not utilized may be covered with a plug 162 or any suitable
cover to keep water and animals out of the mast 12, as illustrated in Fig. 2.
[0076] A method for shipping and installing the MLP assembly 10 may
comprise stacking a plurality of MLP assemblies in a folded configuration and
a substantially horizontal orientation, as illustrated in Fig. 8, such that at
least
some of the stacking brackets 24-30 of one MLP assembly engage with at
least some of the stacking brackets 24-30 of another MLP assembly, as
illustrated in Fig. 9. The one or more MLP assemblies may then be
transported via automobile, train, boat, etc. Once the MLP assemblies reach
an installation site, the desired MLP assembly 10 or a top one of the MLP
assemblies may be removed from the vehicle and placed horizontally on the
ground or an installation surface. The components of the MLP assembly 10
may be unfolded into and/or bolted into an unfolded configuration. Then the
MLP assembly 10 may then be actuated into an upright, substantially vertical
orientation. The temporary base frame 94 may then be removed and the
base plate 90 may be secured to a desired location, such as the ground or
another base secured to the ground, as illustrated in Figs. 1-4.
[0077] In some embodiments of the folded configuration, as illustrated
in Figs. 8-9, the ladders 18,20, at least one of the F-brackets 136, and/or
the
vertical supports 40 may not be bolted to other components of the MLP
assembly 10, but rather are banded to the MLP assembly 10 with any sort of
21
CA 02717126 2010-10-07
strong cords or rope known in the art to bundle a plurality of stacked
components together. The middle rails 38 may be pivoted about a single bolt
in a direction away from the base 22 to be placed into the folded
configuration
illustrated in Fig. 8 and may be pivoted about that same single bolt in a
direction toward the base 22 to be placed in the unfolded configuration.
[0078] The top rails 36 may be pivoted about two bolts, one extending
through each of the pivotable straps 68 of the top rails 26, in a direction
toward the base 22 to be placed into the folded configuration illustrated in
Fig.
8 and may be pivoted in a direction away from the base 22 to be placed in the
unfolded configuration. The top rails 36 may each be placed into the folded
configuration after the middle rails 38 are folded or pivoted into the folded
configuration, such that the middle rails 38 rest between the top rails 36 and
the mast 12 in the folded configuration.
[0079] The platforms 34 may each be pivoted about two bolts, one
extending through each of the pivotable straps 52 of the platforms 34, in a
direction away from the base 22 to be placed into the folded configuration
illustrated in Fig. 8 and may be pivoted in a direction toward the base 22 to
be
placed in the unfolded configuration. The platform 34 may be placed into its
folded configuration after the top rails 36, such that both the top rails 36
and
the middle rails 38 rest between the platform 34 and the mast 12.
[0080] The lower ladder support 145 and/or the middle ladder support
147 may also be pivoted about two bolts, one extending through each of the
first and second mast attachment plates 146,148, in a direction away from the
base 22 to be placed into the folded configuration illustrated in Fig. 8 and
may
be pivoted in a direction toward the base 22 to be placed in the unfolded
configuration. The attachment strip 142 may be bolted to the retaining tab
156 when the lower ladder support 145 is in the folded configuration.
[0081] The F-brackets 136 that are fixedly attached to the platform
assemblies 14,16 in the unfolded configuration may remain fixedly attached in
both the folded and the unfolded configurations of the MLP assembly 10.
Alternatively, the F-brackets 136 may be unbolted from the platform
assemblies 14,16 and banded thereto for transport and then bolted to the
appropriate platform support angle 54 at the installation site. In some
embodiments of the invention, the F-bracket bolted to the top rail 36 of the
22
CA 02717126 2010-10-07
upper platform assembly 16 may be unbolted therefrom in the folded
configuration and then bolted thereto along with one of the vertical supports
40 in the unfolded configuration, while the F-brackets 136 bolted to the
platforms 34 may remain bolted thereto in both the folded and unfolded
configurations.
[0082] Once all of the MLP assembly components are in the folded
configuration, the ladders 18,20 and the vertical supports may be stacked
onto the folded MLP assembly 10 and banded thereto, as described above
and illustrated in Fig. 9. Additionally, any other components unbolted from
the
MLP assembly 10 in the folded configuration may be stacked onto and
banded to the folded MLP assembly 10. Bolts and any other small loose
components required to fix the MLP assembly 10 in its unfolded configuration
may be stored in the electrical box 158 or otherwise temporarily attached to
the MLP assembly 10 for transport.
[0083] Additionally, the temporary base frame 94 may be attached to
the base plate 90 by bolting the diagonal support strip to the base plate 90.
The temporary base frame 90 may be attached such that the first base
stacking bracket 24 is on an opposite side of the mast 12 than the platform
assemblies 14,16 and the second base stacking bracket 26 is on the same
side of the mast 12 as the platform assemblies 14,16.
[0084] Once the MLP assembly 10 is in the folded configuration, it may
be loaded on a vehicle for transportation to an installation site. The MLP
assembly 10 may be stacked on top of other MLP assemblies and/or may
have other MLP assemblies stacked on top of it, as illustrated in Fig. 9. For
example, a first base stacking bracket of a first MLP assembly may rest on top
of a second base stacking bracket of a second MLP assembly, and a first top
stacking bracket of the first MLP assembly may rest on top of a second top
stacking bracket of the second MLP assembly. In one example, four MLP
assemblies are stacked on top of each other in the folded configuration on a
trailer or flatbed truck to be transported to one or more installation sites.
[0085] When the MLP assembly 10 is unloaded at the installation site, it
may be unloaded and placed on the ground in a horizontal orientation on the
first base stacking bracket 24 and the first top stacking bracket 28, as
illustrated in Fig. 8, thereby keeping all other components of the MLP
23
CA 02717126 2010-10-07
assembly 10 off of the ground. This allows easy access to all components of
the MLP assembly 10 and keeps critical components of the MLP assembly 10
out of the mud or other undesirable ground conditions. The stacking brackets
24-30 may further comprise or be loaded onto slide plates (not shown) for
easy loading and unloading into trucks or containers.
[0086] To install the MLP assembly 10, an individual may cut or unbind
the ladders 18,20, F-brackets 136, and/or the vertical supports 40 from the
mast 12. Then the top ladder support 145 may be unbolted from the retaining
tab 156 and pivoted to a substantially 90 angle relative to the center axis
of
the mast 12, as illustrated in Figs. 10-11. Additionally, in some embodiments
of the invention, the middle ladder support 147 may be unattached from one
of the mast attachment plates 125 and pivoted to a substantially 90 angle
relative to the center axis of the mast 12. Once the lower and/or middle
ladder supports 145,147 are in the unfolded configuration, at least one or two
additional bolts may be inserted through holes in the first mast attachment
plate 146 and extend through corresponding holes in the first ladder support
plate 152 to fixedly secure the lower and/or middle ladder supports 145,147 in
the unfolded configuration.
[0087] Furthermore, the platforms 34 may be pivoted to a substantially
901 angle relative to the center axis of the mast 12 about bolts extending
through the pivotable straps 52 of the platform 34 and through the
corresponding first and second mast attachment straps 130,132, as illustrated
in Figs. 10-12. The pivot limiting tabs 134 may prevent the platforms 34 from
rotating further than 90 . Then at least one additional bolt may be inserted
through one or more holes of at least one of the pivotable straps 52 of the
platforms 34 and extend through corresponding holes in the corresponding
first and/or second mast attachment straps 130,132 to fixedly secure the
platforms 34 in the unfolded configuration.
[0088] Then, as illustrated in Fig. 13, the top rails 36 may be pivoted to
a substantially 90 angle relative to the center axis of the mast 12 and be
fixed
in that unfolded position by the insertion of at least one additional bolt
through
one or more holes of at least one of the pivotable straps 68 of the top rails
36.
The additional bolt or bolts may also extend through corresponding holes in
24
CA 02717126 2010-10-07
the corresponding first and/or second mast attachment straps 130,132 to
fixedly secure the top rails 36 in the unfolded configuration.
[0089] Next, as illustrated in Figs. 14-15, the middle rails 38 may be
pivoted to a substantially 900 angle relative to the center axis of the mast
12
and be fixed in that unfolded position by the insertion of at least one
additional
bolt through holes of each of the mast attachment tabs 72 of the middle rails
38 and corresponding holes in the corresponding middle rail-mast attachment
tabs 126,128 extending from the mast 12. In some embodiments of the
invention, the additional bolts are not required, since attachment to the
vertical
supports 40 substantially fixes the middle rails 38 in the unfolded
configuration.
[0090] The vertical supports 40 may each then be bolted to one or
more of the platforms 34, top rails 36, and middle rails 38, as illustrated in
Fig.
15. For example, the vertical support attachment straps 56,66 may be fixedly
bolted to the upper and lower vertical support plates 78,80 and the middle
rail
attachment tabs 82 may be fixedly bolted to the vertical support attachment
plates 74 of the middle rails 38. Simultaneously, one of the F-brackets 136
may be bolted to one of the vertical supports 40 and the top rail 36 of the
upper platform assembly 16 by placing one or more bolts through holes in the
F-bracket, corresponding holes in the vertical support attachment straps 66
and corresponding holes in the upper vertical support plate 78.
[0091] Next, one of the ladders 18,20 may be bolted to at least one of
the F-brackets 136, the lower ladder support 145, and/or the middle ladder
support 147. For example, a first ladder 18 may be attached to the lower
ladder support 145 and/or the F-bracket attached to the middle platform
assembly 14, and a second ladder 20 may be attached to the one or two F-
brackets 136 attached to the upper platform assembly 16, as illustrated in
Figs. 1-2. In an alternative embodiment of the invention, the first ladder 18
may be attached to the lower ladder support 145 and/or the middle ladder
support 147, as illustrated in Figs. 3-4. Then the first and second ladders
18,20 may be bolted together to form a single ladder. Alternatively, a single
ladder may be used. However, the use of two or more ladders may be
advantageous for allowing a single individual to install the ladders 18,20
onto
the MLP assembly 10.
CA 02717126 2010-10-07
[0092] Once the ladders 18,20 and the vertical supports 40 are fixedly
bolted into place in the unfolded configuration, the MLP assembly 10 may be
reoriented from its horizontal orientation to its vertical orientation, as
illustrated
in Figs. 1-4. For example, one or more individuals, a crane, and/or other
lifting equipment may be attached to the MLP assembly 10 and may actuate it
from the horizontal to the vertical orientation. In one embodiment of the
invention, the crane may be attached at or proximate a top end of the mast 12
and may lift the MLP assembly 10. For example, the crane may be hooked to
a cord or strap wrapped around the mast 12 and/or the bracket extensions
116. The crane may lift the MLP assembly 10 in a direction such that the
MLP assembly 10 pivots relative to the ground or installation surface on its
rocker straps 106,108 from the horizontal to the vertical orientation as it is
being lifted by the crane. Once in the vertical orientation, the MLP assembly
may continue to be lifted slightly above the ground or installation surface
such that the temporary base frame 94 may be removed from the base 22,
such as by unbolting the diagonal support strip 104 therefrom.
[0093] The crane may then lower the MLP assembly 10 onto the
ground or an installation surface such that the base plate 90 may be anchored
thereto using bolts or any other mechanical fasteners required, as illustrated
in Figs. 1-4. In some embodiments of the invention, the bottom ladder
support (not shown) may be bolted to a bottom end of one of the ladders
18,20 closest to the ground and the bottom ladders support may be at least
partially buried in the ground to further anchor the ladders 18,20. Then the
crane and/or the stacking brackets 28,30 may also be removed from the MLP
assembly 10.
[0094] The method and MLP assembly 10 described herein provides a
variety of advantages over prior art MLP assemblies. For example, the
stacking bracket arrangement may allow 16 MLP assenblies to be shipped on
one flatbed truck, with the MPL assemblies stacked 4 high. In contrast, only
about 5-8 prior art MLP assemblies could be shipped on one flatbed truck.
Furthermore, the stacking brackets 24-30 may be unbolted from the MLP
assembly 10 and reused. The MLP assembly 10 does not require external
packing materials or crates and may be shipped as one complete, self-
contained unit. The temporary base frame 94 provides a wider base for
26
CA 02717126 2010-10-07
stabilizing the mast 12 while lifting, such that the MLP assembly 10 may be
prevented from rolling. The top stacking brackets 28,30 and their
corresponding bracket extensions 116 may also provide a secure place to
attach lifting cords or straps (not shown) for reorienting the MLP assembly 10
from the horizontal to the vertical orientation.
[0095] Further advantages of the MLP assembly include the platform
34 and rails 36,38 being formed of tubes, which reduce twist and provide
greater stability and strength than angle rails or rigid strap frames used in
prior art MLP assemblies. Also, because most of the assembly takes place
prior to shipment of the MLP assembly 10, one individual can assemble the
MLP assembly 10 at the installation site in approximately one third of the
time
it would take a typical 5-person crew to assemble the prior art MLP assembly
at the installation site.
[0096] Although the invention has been described with reference to the
preferred embodiment illustrated in the attached drawing figures, it is noted
that equivalents may be employed and substitutions made herein without
departing from the scope of the invention.
27
