Note: Descriptions are shown in the official language in which they were submitted.
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Title: BRIDGE OVERHANG BRACKET
Field of the invention
[0001] This invention
relates to shoring devices, for example, brackets
used for bridge overhangs.
Background of the invention
[0002] Bridges typically have
decks that extend laterally outwardly
beyond structures that support the decks. To construct such overhanging
portions of the deck, a bridge overhang bracket is provided, having bracket
members for transferring load from the deck overhang portion to the
supporting structures.
[0003] Bridge
overhang brackets may have three primary members,
namely, a top (generally horizontal) member, a side (generally vertical)
member, and a diagonal member. The three members (also referred to as
legs) are bolted together near their ends to form a rigid triangle. The
horizontal member is fitted with a bolt holder at a point in between the ends
of
the horizontal member. To use the bracket, it is placed against a beam,
column or other part of the structure Of a bridge being built. A bolt is
placed
through the bolt holder and attached to a hanger on the beam or column to
hold the bracket up. The horizontal member extends generally horizontally
from a proximal end abutting the beam or column to a distal end. The Vertical
member extends downwards from an upper end, attached to the proximal end
of the horizontal member to a lower end that abuts against a lower part of the
beam or column. The diagonal member is attached to and spans between the
distal end of the horizontal member and the lower end of the vertical member.
After several such brackets are placed along a beam or series of columns,
joists or parts of formwork are laid across the horizontal members to provide
a
shored surface, such as a form for pouring a cantilevered portion, or
overhang, of a concrete bridge deck.
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Summary of the invention
[0004] It is an object of the invention to improve on the prior
art. It is
another object of the present invention to provide a bridge overhang bracket
and elements of a bridge support system. These and other objects are
provided by the features described in the claims. The following summary
provides an introduction to the invention which may reside in a combination or
sub-combination of features provided in this summary or in other parts of this
document.
[0005] The invention provides a bridge overhang bracket that
comprises a horizontal member, a diagonal member and a vertical member.
The horizontal member has a distal end and a proximal end. The proximal
end may be fitted with an abutment for bearing against a column, beam or
other supporting structure. A bolt holder is attached to the horizontal member
between its ends for attachment to a bolt or rod running to a hanger or other
part of the supporting structure. The diagonal member is attached at one end,
for example pivotably, to the distal end of the vertical member. A second end
of the diagonal member may be fitted with another abutment for bearing
against another part of the supporting structure. The vertical member is
attached, for example pivotably, to the proximal end of the horizontal member
and the second end of the diagonal member.
[000G] In one of its aspects, the invention provides a bracket in
which a
member, such as the vertical member, has a length between its points of
attachment to the horizontal and diagonal members that is infinitely
adjustable. Being infinitely adjustable, the length of the vertical member
between its points of attachment can be tailored to a large variety of
supporting structures, can accommodate for inconsistencies in the shape of
the supporting structure, or to angle the horizontal member such that, when
loaded, the horizontal member corresponds to a desired angle. In another
aspect, the invention provides a bracket with a member, such as the vertical
member, with a length between attachment points that can be altered without
disassembling the bracket. In this way, the bracket may be more easily
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adjusted after it is installed against a supporting structure. In another
aspect,
the invention provides a bracket with a member, such as the vertical member,
with a length between points of attachment that may be adjusted at or above
the vertical member, for example by rotating the vertical member or by
adjusting the attachment between the vertical and horizontal members. In this
way, adjustments made after a bracket is installed against a supporting
structure may be made from the top of the supporting structure. In another
aspect, the invention provides a bracket with a vertical member that may slide
in one of its points of attachment, for example its attachment with the
vertical
member. In this way, the bracket may be made foldable without requiring
disassembly of the bracket.
[0007] Two or more of the aspects described above may be combined
in various embodiments. In an exemplary embodiment, to be described in
detail, all of these aspects are combined. In that embodiment, the vertical
member is a threaded rod. The horizontal and diagonal members are fitted
with pins that can pivot in holes in the horizontal and diagonal members. The
vertical member passes through these holes. The ends of the vertical
member extend beyond the pins and have nuts threaded onto them. When
the horizontal and diagonal members are spread apart, the nuts on the
vertical member bear against the pins so that the vertical member may be
loaded in tension. Turning either of the nuts changes the length of the
vertical
member between the pins, allowing the bracket to be adjusted. The bracket
can be folded by pivoting the horizontal and diagonal members together which
causes the vertical member to slide through one or both pins.
[0008] Although the words "vertical" and "horizontal" are used in this
document, the various members of the bracket may depart significantly from a
strictly vertical or horizontal orientation. For example, the horizontal
member
may be angled upwards or downwards to comply with a sloping bottom
surface of a bridge overhang. The vertical member may be angled towards or
away from a beam or column as required to account for the shape of the
beam or uolumn or various locations of its attachment with the vertical
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member. Further, while each member has been described in the singular,
each member may be made up of two or more individual pieces connected
together. For example, a member may be made of two or more nesting
channels or telescoping rods or tubes that may be bolted together to provide
members having a set of possible lengths. Further, one or more of the
members may be fitted with a series of holes such that other members or
components can be attached to it at a variety of locations. Additional
features
may also be added to the bracket. For example, the distal end of the
horizontal member may be fitted with a bracket to hold a guardrail or the
vertical member may have channels to accept the heads of T-bolts or other
fasteners.
Brief description of the drawinps
[0009] For a better understanding of the present invention and to
show
more clearly how it may be carried into effect, reference will now be made by
way of example, to the accompanying drawings that show embodiments of
the present invention, and in which:
[0010] Figures 1 and 2 are perspective views of a plurality of
bridge
overhang brackets 100 according to the present invention shown in
combination with a bridge support structure;
100111 Figure 3 is a side view of one of the brackets of Figure 1;
[0012] Figure 4 is a perspective view of the bracket of Figure 3;
100131 Figure 5 is a cross-sectional view of a portion of the
bracket of
Figure 4 taken along the lines 5-5;
[0014] Figure 6 is another perspective view of the bracket of Figure 3;
[0015] Figure 7 is an enlarged side cross-sectional view of a
portion of
the bracket of Figure 6;
[0016] Figure 8 is a front view of the portion of the bracket of
Figure 7;
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[0017] Figure 9 is an alternate embodiment of a portion of the
bracket
of Figure 7;
[0018] Figure 10 is a perspective view of the hanger element of the
bracket of Figure 3;
[0019] Figure 11 is a perspective view of the diagonal member of the
bracket of Figure 3;
[0020] Figure 12 is a cross-sectional view of the member of Figure
11;
[0021] Figure 13 is a perspective view of an end element for
attachment to the member of Figure 11; and
[0022] Figure 14 is a side sectional view of a portion of an alternate
embodiment of a bracket in accordance with the present invention
Detailed description of the invention
[0023] A bridge overhang bracket according to the present invention
is
shown generally at 100 in Figures 1 and 2. In Figures 1 and 2, about five
brackets 100 are shown in combination with a concrete beam 102 for
supporting a bridge deck 1D4.
[0024] Referring now to Figure 3, the bracket 100 has three members,
namely, a generally horizontal top member 112, a generally vertical side
member 114, and a diagonal member 116 extending between the top and
side members. The terms top, side, and diagonal are used to assist in
describing the invention, and are not intended to be limiting. The top and
side
members may depart significantly from the horizontal and vertical,
respectively.
[0025] The top member 112 has an inner end 112a and an outer end
112b. The diagonal member 1'16 also has inner and outer ends 116a and
116b, respectively. In use, (Figures 1 and 2) the inner ends 112a and 116a
are nearest the beam 102 or other supporting structure, while the outer ends
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. 112b and 116b are the outboard ends of the respective members
112 and
116, furthest from the beam 102.
[0026] A pivot joint 118 is provided adjacent the outer
ends 112b and
116b for pivotally connecting together the top and diagonal members 112 and
116. As best seen in Figures 4 and 6, in the embodiment illustrated, the top
member 112 comprises a pair of spaced-apart C-channel members 120
secured together by bolts 122. Aligned holes 124 are provided in the
members 122. Nested lengths of C-channels 120 can be provided to form a
telescoping top member 112 that can be lengthened or shortened as desired.
T-bolt sub-channels 129 can be provided along the upper and lower surfaces
of the C-channels 120 to facilitate connection to other scaffolding elements.
The outer end 112b of the top member can be provided with a railing post
receptacle 161 to support a railing 162 (Figures 4 and 2).
[0027] As best seen in Figures 3, 11, and 12, the diagonal
member 116
comprises a length of square channel 117, and a hole 126 is provided
adjacent the outer end 116b of the member 116. The holes 126 can be
aligned with a set of opposing holes 124 to receive a pivot pin 119 and
thereby provide the pivot joint 118. Cotter pins 128 can be used to secure the
pivot pin 119 (Figure 5). An array of holes 124 can be provided along the
length of the top member 112 adjacent the outer end 112b, so that the
position of the pivot joint 118 can be incrementally adjusted along the length
of the member 112 (Figure 3). The lower surface of the diagonal member 116
can be provided a T-bolt sub-channel 129. An end cap 115 can be affixed to
the inner end 116a of the diagonal member 116 to provide a sliding contact
against the support structure 102 (Figures 4, 13, and 2).
[0028] Referring to Figure 6, the side member 114 has upper
and lower
ends 114a and 114b, respectively, and extends between the top member 112
and the diagonal member 116. More specifically, pivot joints 130 are provided
adjacent the inner ends 112a and 116a of the top and diagonal members 112
and 116, respectively, and the side member 114 extends between the pivot
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joints 130. In the embodiment illustrated, the side member 114 comprises a
length of threaded rod.
[0029] According to the present invention, at least one of the
pivot
joints 130 comprises an adjustable pivot connector 132. The adjustable pivot
connector 132 provides both a pivoting connection and an adjustable axial
engagement mechanism 133 for adjusting, with infinite adjustability, the
operative position of the connector 132 along the length of the side member
114. The term operative position is used because the side member 114 will
generally be in tension when in use to support an overhanging portion of a
bridge deck. In other words, the inner ends 112a and 116a of the upper and
diagonal members 112 and 116 are urged apart from each other when under
normal loads, as indicated by arrows 134. Accordingly, the position of the
pivot joints 130, relative to the length of the side member 114, will be urged
towards the distal upper and lower ends 114a, 114b of the side member 114.
The adjustable axial engagement mechanism 133 need only restrain the
connector 132 from moving outwardly relative to end of the side member 114.
[0030] Referring now to Figures 7 and 8, further details of an
embodiment of the connector 132 will be described. The connector 132
comprises a pivot pin 136 that extends between generally horizontal, aligned
holes 138 in opposed walls of the diagonal member 118, at a position
adjacent the inner end 116a. The pivot pin 136 can be retained in position
across the member 116 by cotter pins 140. The same structure can be used
for providing the connector 132 at the upper pivot joint 130 in the top member
112.
[0031] The pivot pin 136 has a cross bore 142 that is directed generally
perpendicular to the axis of the pin 136, and positioned intermediately along
the length of the pin 136. The cross bore 142 is sized to receive the side
member 114 in sliding frt. An elongate slot 143 is provided in the upper and
lower walls of the diagonal member 116 to accommodate the side member
114 and permit it to freely pivot about the pin 136. An adjustable axial
engagement mechanism 133 in the form of a retaining nut 144 is threaded on
=
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to the threaded rod (side member) 114, between the pin 136 and the distal
end (the lower end 114b in Figures 7 and 8) of the side member 114. An
optional spacer 146 can be provided between the pin 136 and the retaining
nut 144 to improve the bearing surface between the pin 136 and the nut 144,
if desired. As seen in Figure 0, the spacer 146 can be omitted so that the nut
144 abuts the outer surface of the pin 136. The slot 143 can be enlarged to
permit access to the nut 144 with a gripping tool for tuming the nut 144.
[0032] In use, the bracket 100 can be assembled on the ground,
using
construction drawings to assemble the bracket 100 to an approximate shape.
The bracket can then be hung from the support structure 102 by passing tie
rods 150 extending from the structure 102 through a hanger 152 attached to
the top member 112 (Figure 2). As best seen in Figures 6 and 10, in the
embodiment illustrated, the hanger 152 has a pair of spaced apart angle
brackets 154 which are bolted to the underside of the top member 112,
adjacent the inner end 112a. A connection bracket 156 is welded across the
underside of the brackets 156. The connection bracket mounted to form a v-
shape, and has an aperture 158 for receiving the tie rod 150.
[0033] Additional bridge overhang brackets 100 can be hung from the
support structure 102 along the length of the bridge as required. Once the
required number of brackets 100 have been hung, adjustments can be made
to the connectors 132 to accommodate any variations encountered in the
shape of the support structure or in the manufacturing and assembly
tolerances of elements within the bracket 100 or any elements to which it is
attached. The weight of the brackets 100, plus any fomnwork or railings that
may be supported by the brackets 100 will generally urge the diagonal
member 116 towards the distal (lower) end 114b of the side member 114.
Accordingly, the pin 136 is urged towards the retaining nut 144. By turning
the retaining nut 144, the (operative) position of the adjustable pivot
connector
132 relative to the side member can be adjusted, without the need far partial
disassembly of any of the brackets 100,
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[0034] Referring again to Figure 5, the nut 144 is provided only
on the
lower (outward) side of the pin 136, thereby restricting the pin 136 from
moving outward, past the nut 144. The sliding fit between the side member
114 and the cross aperture 142 of the pin 136 can allow a pre-assembled
bracket 100 to be conveniently collapsed at least to a certain degree by
sliding the inner ends 112a and 116a towards each other (particularly in cases
where both the upper and lower pivot joints 130 comprises the connectors
132). An optional nut 145 (shown in phantom in Figure 7) can be provided
above the pin 136 (opposite the nut 144), spaced apart from the pin 136 prior
to installation of the bracket 100. The nut 145 can be tightened against the
pin 138 after adjustment of the nut 144, so that the bracket 100 can withstand
some light compression forces prior to pouring the bridge deck, such as from
wind loads, which may otherwise cause some undesired movement of the
bracket members.
[0035] . Referring now to Figure 14, another embodiment of an overhang
bracket 200 is shown. The overhang bracket 200 is similar to the bracket 100,
and like elements are identified by like reference characters Incremented by
100. Like elements of overhang bracket 200 not shown in Figure 14 are the
same as for bracket 100. The overhang bracket 200 is provided with an
adjustable pivot connector 232 for connecting the side member 214 to the
diagonal member 216. The adjustable pivot connector 232 provides both a
pivoting connection and an adjustable axial engagement mechanism 233 for
adjusting, with infinite adjustability, the position of the connector 232
along the
length of the side member 214.
[0036] The connector 232 includes a generally cylindrical lower pivot
pin 236' that extends generally horizontally between opposed sidewalls of the
diagonal member 216, at a position adjacent the inner end 216a. The pivot
pin 236'. is mounted within the diagonal member 216 to be freely rotatable
about the axis of the pin 236'.
[0037] The pivot pin 236' is provided with a cross bore 242'. The cross
bore 242' has intemal threads 244 to engage a threaded portion of the side
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member 214, and thereby provide the connector 232 with a lower thread
engaging member of the adjustable axial engagement mechanism 233. In the
embodiment illustrated, side member 214 is a threaded rod allowing
engagement of the pivot pin 236' anywhere along the length of the side
member 214.
[0038] Adjacent the upper end 214a of the side member 214, a pivot
joint 230 is included for providing a pivoting connection between the top
member 212 and the side member 214. The pivot joint 230 has an upper
pivot pin 236 that is mounted in the top member 212 so as to be freely
rotatable about Its generally horizontally aligned axis. The pivot pin 236 has
a
cross bore 242 that extends through the pivot pin 236, generally
perpendicularly to the axis of the pin 236. The cross bore 242 is sized to
receive the side member 214 in sliding fit.
(00391 An upper portion of the side member 214 projects upwardly
from
the cross bore 242 of the pin 236 and is provided with an engagement
element 247. The engagement element 247 restricts axial movement of the
side member 214 through the cross bore 242 of the pin 238. Further, in the
embodiment illustrated, the engagement element 247 provides a grip surface
249 that can be used to rotate the side member 214 to effect axial
displacement of the side member 214 with respect to the adjustable connector
232. In the embodiment illustrated, the engagement element 247 and grip
surface 249 are provided in the form of a nut 245a securely fixed to the side
member 214 (such as by welding) to prevent relative rotation between the
side member 214 and the nut 245s.
[0040] A spacer 248a can optionally be provided between the
engagement element 247 and the pin 236 of the pivot connection 230. The
spacer 246a can have an axial extent such that the engagement element 247
is disposed at or above (i.e. clear of) the upper surface of the top member
212. This can facilitate access to the engagement element 247 (i.e. the grip
surface 249) for adjusting the bracket 200, for example by a wrench or other
tool. The spacer 246a may also place the engagement element 247 such
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that, while the engagement element 247 is disposed above the upper surface
of the top Member 212 and easily accessed by a tool, it is not disposed so far
above the top member 212 to interfere with the bottom of a mold placed on
joists in beams running perpendicular to the top Members 212 between
adjacent overhang brackets 200. Turning the engagement element 247
causes the portion of the lower pivot pin 238 to move relative to the lower
end
214b of side member 214. During the adjustment, the engagement element
247 remains in its initial position vertically, optimally a position in which
it is
clear of the upper member 212 but below the mold for a bridge deck 104. The
lower end =214b and side member 214 may protrude to varying lengths
beyond the diagonal member 216, but such protrusion rarely interferes with
other structures. If such protrusion does interfere with another structure, a
shorter side member 214 may be used.
[0041] In use, the bracket 200 can be pre-assembled to an
estimated
size and/or configuration, and can then be mounted in place on the side of a
bridge support structure such as a concrete beam 102 as shown in Figures 1
and 2. When so mounted, the side member 214 will generally be in tension
(i.e. the diagonal member 216 exerts a downward force, when viewed as in
Figure 14). The engagement element 247 bears against the upper surface of
the pin 236 (through the spacer 246a, when provided) to counteract this
downward force. Fine adjustment of the bracket 200 can be made by gripping
the grip surface 249 and applying a torque to rotate the side member 214.
Rotating the grip surface 249 (and hence side member 214) in one direction
(e.g. clockwise) can draw the diagonal member 216 upwards, while rotating in
the opposite direction can lower the diagonal member 216. A cotter pin 251,
optimally placed through a hole in a second nut 252, or another structure
providing an abutment can be provided at the lower end 214b of the side
member 214 to prevent inadvertent disengagement of the side member 214
from the pin 236' when lowering the diagonal member 216. Having the grip
surface 249 exposed above the upper surface of the top member 212 can
facilitate locating, gripping, and rotating the grip surface 249, and can
provide
adjustment capability from atop the bridge support structure. Furthermore, in
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the embodiment illustrated, the grip surface 249 is located proximate the
inner
end of the top member 212, being positioned generally in axial alignment with
the side member 214. This position of the grip surface 249 can facilitate
adjustment of the axial engagement member by a person positioned on or
near the support structure (102 in Figures 1 and 2) from which the bracket
200 is hung.
[0042] Once the fine adjustment has been completed, unexpected
upward movement of the diagonal member 216 with respect to the top
member 212, for example, by wind before the bracket 200 is loaded, can be
inhibited by tightening a retaining element such as a third nut 245b along the
side member 214 and against the lower surface of the pin 236. A spacer
246b can be provided between the lower surface of the pin 236 and the third
nut 245b, to keep the third nut 245b below the lower surface (i.e. clear) of
the
top member 212 and thereby facilitate access to the third nut 245b.
