Note: Descriptions are shown in the official language in which they were submitted.
CA 02796153 2012-11-20
TITLE
[0001] Temporary Bridge
FIELD
[0002] There is described a temporary bridge that was developed to enable
construction
equipment to cross sidewalks to access construction sites. It will be
appreciated that the
temporary bridge may be used to cross streams, drainage ditches, or buried
utilities.
BACKGROUND
[0003] Roads and sidewalks are currently being installed in subdivisions.
When lots are
sold, construction equipment must cross the sidewalks to access the lot on
which construction
is taking place. Construction equipment is causing damage to sidewalks, which
is often
requiring entire sections of the sidewalks to be replaced. There have been
various solutions
proposed, but they have not proved to be effective. There will hereinafter be
described a
temporary bridge which was developed to avoid damage to sidewalks by
construction
equipment.
SUMMARY
[0004] There is provided a temporary bridge which includes at least one
arched body
having a first end and a second end. Each arched body includes a plurality of
vertically
oriented parallel spaced arch members extending from the first end to the
second end of the at
least one arched body. Each of the arch members has a convex upper surface, a
concave
lower surface, and flat opposed sides. A plurality of vertically oriented
parallel spaced
transverse members are positioned transversely between the opposed sides of
the arch
members and service to define a framework of box reinforcement structures. An
upper travel
surface is supported by the convex upper surface and secured to the box
reinforcement
structures. A lower structural covering is provided on the concave lower
surface. The lower
structural covering is secured to the box reinforcement structures.
[0005] The temporary bridge, as described above, is intended to take the
weight of
cement trucks and other types of transport vehicles hauling supplies and
equipment to a
construction site. When the weight of a vehicle is on the structure, the upper
travel surface is
placed in compression and the lower structural covering is placed in tension.
The combination
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of elements with the reinforcing box structures increase the load bearing
capability of the
temporary bridge. It is anticipated that the arch members and the transverse
members will
both be made of structural metal plate. It is similarly anticipated that the
upper travel surface
and the lower structural covering are both made of structural metal plate. It
is appreciated that
the use of structural metal plate is not required if the load bearing
requirements are not as
demanding as a construction site application.
[0006] It has been found that an offset arrangement of the transverse
members results in a
stronger structure. In accordance with this aspect, the transverse members
serving to define
the box reinforcement structures between one pair of arch members is offset
from transverse
members serving to define the box reinforcement structures between an adjacent
pair of arch
members.
[0007] There are various ways to tie the upper travel surface to the box
reinforcement
structures. In the embodiment which will hereinafter be described, each of the
transverse
members have upwardly projecting connective vanes which are received in slots
in the upper
travel surface to tie the box reinforcement structures to the upper travel
surface and provide a
rigidity to the box reinforcement structures. It has been found that when the
vanes project
above the upper travel surface, they also serve to provide a non-skid profile
for the upper
travel surface.
[0008] The terrain upon which the temporary bridge is to be installed may
vary. For that
reason it is preferred that the at least one arched body has an access ramp
attached to at least
one of the first end or the second end. An access ramp can be used to
accommodate the first
end and the second end of the temporary bridge to suit surface grade. It has
been determined
that it is advantageous to have each access ramp pivotally mounted by means of
hinges. This
allows the access ramp to "float" on the hinges to whatever level is necessary
to
accommodate the surface grade. It also allows the access ramp to pivot about
the hinges
between an operation position extending past one of the first end or the
second end and a
stored position.
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[0009] Where surface loading is a concern, a weight distributing ground
pad may be
positioned at one of a first end or a second end of the concave lower surface.
Where sliding
movement of the ground pad is of concern, the ground pad may be provided with
a ground
engaging profile to retard movement of the ground pad. How aggressive the
ground engaging
profile is will depend upon whether it is anticipated that it is rest upon a
roadway or vacant
land.
[0010] It has been found that frequently transport vehicles must back
over the temporary
bridge. Where this is anticipated, it is preferred that the upper travel
surface has peripheral
side edges with vertically extending edge delimiters. Striking the edge
delimiters serves as a
warning to the driver of the transport vehicle, that the vehicle is in danger
of driving off an
edge of the temporary bridge. In the illustrated embodiment, side rails have
been used as the
edge delimiters.
[0011] It is possible to fabricate a large arched body which is wide enough
to
accommodate all anticipated vehicular traffic. However, it is preferred that
two arched bodies
be connected in parallel spaced relation. Each of the two arched bodies
provides the upper
travel surface that accommodates one of the wheels of the transport vehicle.
[0012] As the axle width of transport vehicles varies, it is preferred that
the two arched
bodies are connected by a length extendible connection that allows a distance
between the
two arched bodies to be adjusted to accommodate vehicles having differing axle
widths.
[0013] As a transport vehicle travels over the temporary bridge, each of
the two arched
bodies may be subjected to some limited pitching and rolling. It is,
therefore, preferred that
the two arched bodies are connected by a flexible connection to accommodate
relative pitch
and roll.
[0014] In the current application of construction sites in new
subdivisions, there is
frequently a difference in elevation from road grade to lot grade. For that
reason it is
preferred that the first end of the at least one arched body has a first
horizontal plane and the
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second end of the at least one arched body has a second horizontal plane that
is one of higher
or lower than the first horizontal plane.
[0015] The rate of ascent and descent onto the temporary bridge has an
effect on how
well the temporary bridge performs. Too dramatic a radius of curvature on the
upper travel
surface can result in the frame of the transport vehicle "bottoming out", at
an intermediate
position between the front wheels and the rear wheels. Where the transport
vehicle has an air
bag suspension, "bottoming out" is less likely. However, the air bag
suspension may operate
to shift weight from one axle onto another axle, resulting in an undesirable
load distribution.
It is, therefore, preferred that the upper travel surface defines a grade of
between 5 degrees
and 8 degrees, which has been found to be a workable grade range. It will be
appreciated
that where an access ramp is used, the upper travel surface in combination
with the access
ramp will define a grade of between 5 degrees and 8 degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features will become more apparent from the
following
description in which reference is made to the appended drawings, the drawings
are for the
purpose of illustration only and are not intended to be in any way limiting,
wherein:
[0017] FIG. 1 is a side elevation view of a temporary bridge.
[0018] FIG. 2 is a side elevation view of the temporary bridge covering a
sidewalk.
[0019] FIG. 3 is a top perspective view, partially in section, of the
temporary bridge
covering a sidewalk.
[0020] FIG. 4 is a detailed view, partially in section, of the box
reinforcement structure.
[0021] FIG. 5 is a bottom perspective view of the temporary bridge.
[0022] FIG. 6 is a side elevation view of the temporary bridge with ramps
in the
operational position.
[0023] FIG. 7 is a side elevation view of the temporary bridge with ramps
in the stored
position.
[0024] FIG. 8 is a perspective view of two temporary bridges connected
together in
parallel spaced relation.
[0025] FIG. 9 is a detailed view of the connection that connects
temporary bridges in
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parallel spaced relation as shown in FIG. 8.
DETAILED DESCRIPTION
[0026] A temporary bridge generally identified by reference numeral 10,
will now be
5 described with reference to FIG. 1 through 9.
Structure and Relationship of Parts:
[0027] Referring to FIG. 1 and FIG. 2, a temporary bridge 10 includes at
least one
arched body 12 with a first end 14 and a second end 16. In the embodiments
shown, first end
14 of arched body 12 has a first horizontal plane 18 and second end 16 of
arched body 12 has
a second horizontal plane 20 that is one of higher or lower than first
horizontal plane 18.
Referring to FIG. 1, first horizontal plane 18 is shown lower than second
horizontal plane 20.
Referring to FIG. 2, first horizontal plane 18 is shown higher than second
horizontal plane 20.
Referring to FIG. 3, each arched body 12 has a plurality of vertically
oriented parallel spaced
arch members 22 extending from first end 14 to second end 16 of arched body
12. Referring
to FIG. 1 and FIG. 2, each of arch members 22 has a convex upper surface 24, a
concave
lower surface 26 and flat opposed sides 28. Referring to FIG. 3 and FIG. 4, a
plurality of
vertically oriented parallel spaced transverse members 30 are positioned
transversely between
opposed sides 28 of arch members 22 and serve to define a framework of box
reinforcement
structures 32. Transverse members 30 serving to define box reinforcement
structures 32
between one pair of arch members 22 are offset from transverse members 30
serving to define
box reinforcement structures 32 between an adjacent pair of arch members 22.
It is preferred
that arch members 22 and transverse members 30 be made of structural metal
plate, however
it may be understood that different materials may be used and that the arch
members and
transverse members need not be made of the same materials. The materials used
should be
based on the load bearing requirements of temporary bridge 10.
[0028] Referring to FIG. 3, an upper travel surface 34 is supported by
convex upper
surface 24 and secured to box reinforcement structures 32. It will be
understood that a portion
of upper travel surface 34 has been removed to reveal underlying structural
detail and that
upper travel surface 34 covers the entirety of convex upper surface 24 as
shown in FIG. 8.
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Referring to FIG. 8, in the embodiments shown, upper travel surface 34 has
peripheral side
edges 36 with vertically extending edge delimiters 38. In the embodiments
shown, side rails
40 have been used as edge delimiters 38, however it will be understood that
different
delimiters may be used. It is preferred that upper travel surface 34 define a
grade of between 5
degrees and 8 degrees, however it will be understood that travel surface 24
may define a
different grade. Referring to FIG. 5, a lower structural covering 42 on
concave lower surface
26 is secured to box reinforcement structures 32. It is preferred that upper
travel surface 34
and lower structural covering 42 both be made of structural metal plate,
however it will be
understood that different materials may be used and upper travel surface 34
and lower
structural covering 42 need not be made of the same material. Materials should
be chosen
based on the load bearing requirements of temporary bridge 10. Referring to
FIG. 4,
transverse members 30 have upwardly projecting connective vanes 44 received in
slots 46 in
upper travel surface 34 to tie box reinforcement structures 32 to upper travel
surface 34 and
provide rigidity to box reinforcement structures 32. Vanes 44 project above
upper travel
surface 34 to provide a non-skid profile for upper travel surface 34.
[0029] Referring to FIG. 1 and FIG. 2, when the weight of a vehicle is on
arched body
12, upper travel surface 34 is placed in compression and lower structural
covering 42 is
placed in tension. Referring to FIG. 4, the combination of elements within
reinforcing box
structures 32 increases the load bearing capability of temporary bridge 10.
[0030] Referring to FIG. 6 and FIG. 7, arched body 12 has an access ramp
48 attached to
at least one of first end 14 and second end 16. Each access ramp 48 is
pivotally mounted by
means of hinges 50. Access ramps 48 pivot about hinges 50 between an operation
position,
shown in FIG. 6, extending past one of first end 14 or second end 16 and a
stored position,
shown in FIG. 7. It is preferred that upper travel surface 34 in combination
with access ramp
48 defines a grade of between 5 degrees and 8 degrees, however it will be
understood that a
different grade may be defined. Referring to FIG. 5, a weight distributing
ground pad 52 is
positioned at one of a first end 54 or a second end 56 of concave lower
surface 26. Ground
pad 52 has a ground engaging profile 58 to retard movement of ground pad 52.
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[0031] Referring to FIG. 8 and FIG. 9, two arched bodies 12a and 12b may
be connected
in parallel spaced relation. The two arched bodies 12a and 12b are connected
by a length
extendible connection 60 that allows a distance between the two arched bodies
12a and 12b to
be adjusted to accommodate vehicles having differing axle widths. Flexible
connection 60
may also accommodate relative pitch and roll of the two arched bodies 12a and
12b.
Operation:
[0032] Referring to FIG. 2 and FIG. 3, temporary bridge 10 is placed over
a sidewalk
100 or other obstacle to be protected. Referring to FIG. 2, concave lower
surface 26 does not
come into contact with sidewalk 100 so no pressure is placed on sidewalk 100
when
temporary bridge 10 is used. As shown in the present embodiment, second
horizontal plane
is lower than first horizontal plane 18. Second horizontal plane 20 may rest
on a road way
while first horizontal plane 18 rests on the ground beyond the sidewalk.
Referring to FIG. 3, a
single temporary bridge 10 may be used to provide a path over the sidewalk.
Temporary
15 bridges 10 may be created of a width large enough to allow an entire
vehicle to cross,
however this size makes moving and storing of temporary bridges 10 more
cumbersome.
Referring to FIG. 8, two temporary bridges 10 may be placed in parallel spaced
relation such
that a vehicle can place the left side tires on one bridge 10 and the right
side tires on a second
bridge 10. When two temporary bridges 10 are used, they are held in place by
length
20 extendible connection 60. The length of connection 60 may be altered to
allow vehicles with
different length axles to cross.
[0033] Referring to FIG. 6, access ramps 48 may be attached to arched
body 12 either
prior to or after positioned of temporary bridge 10. When attached to arched
body 12, ramps
48 are pivotal on hinges 50 between an operable position and a stored
position, shown in
FIG. 7.
[0034] In this patent document, the word "comprising" is used in its non-
limiting sense to
mean that items following the word are included, but items not specifically
mentioned are not
excluded. A reference to an element by the indefinite article "a" does not
exclude the
possibility that more than one of the element is present, unless the context
clearly requires that
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there be one and only one of the elements.
[0035] The scope of the claims should not be limited by the preferred
embodiments set
forth in the examples, but should be given a broad purposive interpretation
consistent with the
description as a whole.
