Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Title: Toe Board Bracket for Scaffolding
FIELD OF THE INVENTION
The present invention relates to scaffolding, and in
particular to a bracket for attaching toe boards to the perimeter of scaffoldingplatforms.
BACKGROUND OF THE INVENTION
Scaffolding structures are erected and used to provide
elevated working platforms for persons and their tools. These structures
are generally temporarily erected at the work site for the duration of the job
10 and then disassembled for use at another work site. Ease and speed of
assembly and disassembly and reusability are desirable characteristics of
scaffolding structures.
Conventional scaffolding is typically erected with separate
end frame members stacked vertically to a desired height and connected
15 together with diagonal bracing members to form a framework. A
removable platform usually rests on and extends between horizontal
members of opposed end frame members.
The platform itself is often constructed of plywood or
horizontal wooden platform boards with vertical toe boards around the
20 exterior perimeter of the platform. The toe boards serve to prevent tools
and equipment from falling off the platform thereby preventing damage to
persons and property that may be below.
There are a number of scaffolding arrangements which
commonly use the end frame members or devices connected to end frame
25 members to hold the toe boards in place. This type of arrangement is
exemplified in Juculano, U.S. Patent No. 3,785,602, and Gostling, U.S. Patent
No. 3,179,212. The toe boards in these arrangements typically must be long
enough to span the entire distance between opposed end frame members.
At the present time, proposals such as those in the above
30 patents have met with little acceptance. Current practice is simply to nail
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the toe boards to the platform boards. Nails give little resistance to forces
tending to push the toe boards outwards.
One known proposal for a toe board bracket is found in
U.S. Patent 3,836,106 (Gray). However, this configuration has a number of
5 disadvantages. It is configured to work with 4 inch wide toe boards and 12
inch thick deck or platform planks. As such, it can not be used at the end of
planks or as it would interfere with plank cleats, i.e. strips underneath
platform boards that prevent slippage of boards. It has rounded internal
corners that would provide a significant gap between the platform boards
10 and the toe boards, which would be too wide. The bracket has relatively
small dimensions, so that it cannot be used as a splice plate, and so that
frequent spacing of the brackets may well be required. It provides serrated
teeth to facilitate securing of the bracket, but this would result in damage to
platform boards when the bracket is removed. It does not hug the plank
15 tightly, i.e. by providing sharp 90~ corners.
In use, toe boards are subject to much misuse and abuse.
They are routinely and frequently impacted by tools and are kicked by the
workers. Consequently, toe boards often become detached.
It is a common provision in regulations for scaffolding
20 that all platforms must have toe boards. They are basic requirement to
prevent tools from being dislodged from platforms and falling. Many
injuries, serious and otherwise, are caused by tools and other articles being
dislodged from platforms in this manner.
Due to the fact that toe boards frequently get dislodged, it
25 is not uncommon for construction sites to be shut down while the toe
boards are replaced. While the toe boards are missing, the scaffolding is
dangerous. The time taken to replace them results in significant down time
and economic loss.
Accordingly, there is a significant need for some sort of
30 bracket or device for securing toe boards in position in a reliable manner,
which bracket should be cheap, simple and reliable. It should also be
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capable of considerable flexibility, and not restrict the configuration of the
scaffolding structure in any way.
A further common problem with existing toe boards, is
that due to the abuse the boards receive and the desire to reuse boards, one
usually has a supply of boards of varying lengths and odd sizes.
There is therefore a need for a toe board bracket which
can incorporate odd size and short toe boards and which can accommodate
short gaps between toe boards, in conventional scaffolding arrangements.
It is to be appreciated that, in this specification including
the claims, reference is made to terms indicating orientation, such as
"horizontal", "vertical", etc. to describe both the bracket and associated
components of a scaffolding assembly. These terms are used to describe the
bracket when oriented for normal use and it will be understood that the
bracket when not in use may be in any orientation.
SUMMARY OF THE PRESENT INVENTION
The present invention is a toe board bracket for use in a
scaffolding assembly which generally has horizontal platform boards and
vertical perimeter toe boards.
In accordance with a first aspect of the present invention,
there is provided a toe board bracket, for use with scaffolding having
generally horizontal platform boards and generally vertical perimeter toe
boards, the toe board bracket being adapted for side mounting and
comprising: an elongate, substantially rigid vertical channel, which is open
at both ends, which comprises inner and outer sides spaced apart to
accommodate interposition of a toe board and a channel base connecting the
sides of the vertical channel and closing off one of the top and the bottom of
the channel, the other of the top and the bottom of the channel being open;
and a single mounting flange secured to and extending substantially
perpendicularly from the inner side of the vertical channel, and adapted to
be fastened to the top of a platform board.
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Preferably, the channel base closes off the bottom of the
channel and the toe board bracket is adapted for side mounting to a
platform board and the mounting flange is vertically spaced upwardly from
the channel base, whereby the mounting flange can be secured to the top of
5 a platform board, with the inner side extending down beside the platform
board, so that abutment of the inner side against a side edge of the platform
board provides resistance to bending loads applied to a toe board secured in
the bracket.
One or both of the inner and outer sides can include
10 apertures for fasteners and vertically extending reinforcing ribs on the
exterior thereof.
To improve the durability of the bracket, especially when
it is formed from a plastics material, it preferably includes a single aperture
in the mounting flange and a tubular rivet therein, for securing the bracket
15 to a platform board.
In accordance with another aspect of the present
invention, the bracket is adapted for mounting on top of a platform board,
and the channel base then connects the sides of the vertical channel at the
top thereof to close off the top of the channel, the mounting flange extends
20 from the bottom of the inner side, and an outer vertical flange is provided,
extending from the bottom of the outer side, for abutting a vertical side edge
of a platform board.
Advantageously, this embodiment includes an outer
horizontal flange extending between the outer side and the outer vertical
25 flange, to space a toe board inwardly from the side edge of a platform board.This version preferably again include a plurality of ribs
extending from the mounting flange around the inner and outer sides on
the base and across the outer vertical and horizontal flanges.
Another aspect of the present invention encompasses a
30 scaffolding assembly, which comprises a three dimensional framework
which defines at least one generally horizontal platform. A plurality of
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platform boards are mounted on the platform to form a substantially
horizontal platform surface. A plurality of toe board brackets, as defined
here, are secured to the platform boards. The flanges of the toe board
brackets are secured to platform boards such that the channel of the toe
board bracket is located adjacent a free outer edge of a platform board. A
plurality of toe boards are located in the channels of the toe board brackets.
The present invention should be simple, reusable,
inexpensive to manufacture, and able to facilitate the use of toe boards of
differing lengths in scaffolding assemblies. The present invention should
provide simple and quick assembly and disassembly of scaffolding
structures.
DESCRIPTION OF THE DRAWING FIGURES
For a better understanding of the present invention and
to show more clearly how it may be carried into affect, referellce will now be
made, by way of example, to the accompanying drawings, which show
preferred embodiments of the present invention and in which:
Figure 1 is a perspective view of a first embodiment of a
toe board bracket in accordance with the present invention from one side
and above;
Figure 2 is a perspective view of the toe board bracket in
Figure 1 from the other side and below;
Figure 3 is a view from one side of the toe board bracket
of Figure 1;
Figure 4 is an end view of the toe board bracket of Figure
l;
Figure 5 is a sectional view along line 5-5 of Figure 4;
Figure 6 is a view of the bracket of Figure 1 from the
underside;
Figure 7 is a view of the toe board bracket of Figure 1 from
the other side;
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Figure 8 is a perspective view of a top mounting toe board
in accordance with a second embodiment of the present invention;
Figure 9 is a side view of the bracket of Figure 8, showing
mounting of the bracket;
Figure 10 is a side view of the bracket of Figures 8 and 9,
when mounted; and
Figure 11 is a perspective view of a scaffolding assembly
according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will first be made to Figures 1-7 which show a
first embodiment of a side mounting toe board bracket.
The first embodiment of a side mounting bracket is
generally denoted by the reference 110. As for the earlier embodiments, this
bracket 110 defines a vertical channel, here denoted 112, with open ends. A
channel base 114 closes off the bottom of the channel and the channel is
defined by an inner channel side 116 and an outer channel side 118. A
mounting flange 120 extends to one side away from the inner channel side
116. The inner side 116 continues into an extension 122.
Here, the flange 120 as best seen in Figure 3, presents a
generally corrugated profile, having raised portions 124 and lower portions
126 alternating therewith, there being lower portions 126 at either end of the
flange 120 and a raised portion 124 in the middle of the flange 120. It can
further be noted that, at a junction with the inner channel side 116, this
effect is accentuated. As shown in Figure 4, the lower portions are intended
to abut a platform board and extend purely horizontally from the inner
channel side 116. The raised portions 124, however, show an inclined part
128, so that the relative vertical spacing between the raised and lower
portions 124, 126, i.e. the corrugated effect, increases towards the inner
channel side 116.
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This is important, to resist the sorts of loads that can be
applied to a toe board 60. A toe board is likely to be struck or subject to loads
near the top thereof. This imparts a clockwise bending moment,
particularly to the outer channel side 118, as viewed in Figure 4. This
bending moment is transferred, mainly through the outer channel side 118,
the base 114 and then through the inner channel side 116 to the flange 120;
some part of it may be transferred directly to the inner channel side 116,
particularly if this is well secured by nails.
Now, the arrangement of this embodiment is designed to
provide good transfer of such moments to the flange 120, and then through
the flange to the platform board. For this reason, the raised and lowered
portions 124, 126 are spaced further apart adjacent the mounting flange 120,
to provide greater resistance to bending moments.
As shown on the underside view of Figure 6, a transverse
strip or pad 130 extends across between the lower portions 126, undemeath
the raised portions 124. In the center of this strip 134, there is an aperture
132 for a mounting nail. This aperture 132 is provided with a steel rivet 134
to reinforce the aperture and to provide adequate wear characteristics. The
rivet 134 is either molded or drilled and pressed into the aperture 132. The
rivet 134 is tubular and includes a collar 34a at the top and a sleeve 34b
lining the aperture.
It can further be noted that, the underneath corner where
the flange 120 meets the inner channel side 116 forms an essentially right
angle corner with only slight rounding of the corner. This ensures that
both the flange 120 and side 116 can closely abut the top and sides of a
platform board. This again ensures good transfer of bending moments. The
abutment of the side 116 against the board edge additionally serves to
transfer bending loads applied to a toe board to the platform board.
Tuming now to details of the inner channel side 116, this
is best shown in Figures 3 and 4. The inner channel side is provided with a
series of ribs 136, including a central rib 137. There are a pair of ribs 136 on
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either side. Each rib 136, 137 comprises a lower portion 136a, 137a and an
upper portion 136b, 137b. The width of the lower portions is typically 0.190
inches, while the width of the upper portions 136b is typically 0.125 inches.
For the depth of the ribs, i.e. in a direction perpendicular
to the side 116, the four side ribs 136 have a uniform height of 0.125 inches,
with the side 116 also having a thickness of 0.125 or 8 th of an inch. It is here
noted that in general, most parts of the bracket have a thickness of 8 (0.125)
inches. The central rib 137 tapers, as shown, to a thickness that approaches
0.25 inches at the lower end thereof.
To further improve the resistance to bending loads
imparted to a toe board, internal gussets or small ribs 138 are provided
between the channel base 114, and the inner and outer channel sides 116,
118.
Turning to the outer channel side 118, this is provided
with a pattern of reinforcing ribs 139, best shown in Figures 4,5,6 and 7.
Here, there are lower rib portions 140, which have the greatest depth (i.e. in
a direction perpendicular to the side 118), as a bending moment will be
greatest at the bottom of the channel. Thus, the lower portions 140 have a
depth of the order of 0.3125 inches, and a width of about 0.190 inches. As
shown in Figure 5, the rib portions 140, and indeed the rib proportions in
general, can be provided with a suitable taper, to facilitate release from a
mold in manner. As shown, there are nine lower rib portions 140.
These lower rib portions 140 blend smoothly into upper
rib portions 142, 143 which have a constant height of 8 of an inch. As,
shown, there is a single, central upper rib portion 142 and two pairs of side
ribs 143. Transverse strips or pads 144 extend between the ribs 143 to
strengthen them.
As shown, the lowermost pads 144 are provided with
apertures 146 for nails, to enable a toe board to be secured within the bracket.Corresponding apertures 148 are provided on the inner channel side 116.
The apertures 146, 148 are aligned, for ease of molding. This enables a single
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mandrel to be used for each pair of apertures 146, 148. In use nails will be
inserted from just one side.
Concerning overall dimensions of the bracket, the
following are typical to mention. It can have a length of 5 inches, and
overall height of 68 inches. The channel 112 has a width of 1 inch, and the
flange 120, in a direction perpendicular to the side 116, a width of 1.875
inches.
To facilitate insertion of a toe board, the inner side 116 is
2 an inch shorter than the outer channel side 118, as shown. Further, as in
an earlier embodiment, the upper edges of the sides 116, 118 are chamfered
or tapered, as indicated at 119.
Reference will now be made to Figures 8,9 and 10, which
show a fourth or top mounting bracket, indicated by the reference 150.
The bracket 150 includes an inner side 152, an outer side
154 and a mounting flange 156. Since this is a top mounting bracket, the
flange 156 extends from the bottom of the inner side 152, and is connected
by an inclined portion 157.
A channel 158 is defined between the sides 152, 154. For
this top mounting version, a channel base 160 forms a top connecting the
sides 152, 154.
The outer side 154 continues into an outer horizontal
flange 162, which in turn continues into an outer vertical flange 164, for
abutting the top and side edges of a platform board respectively.
As in the other embodiments, reinforcing ribs are
provided. On the exterior, there are a three reinforcing ribs 166 which
extend from the mounting flange 156 to the outer vertical flange 164. These
three ribs all have a similar profile. As shown, each rib has a width of
thickness of 0.25 inches and a depth or height of over the outer horizontal
and vertical flanges 162, 164 of 0.375 inches. This depth of height reduces to
0.25 inches for the remainder of the ribs 166. As shown, the internal corners
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of this bracket are generally rounded, with other thicknesses generally being
0.125 inches. The inclined portion 157 is at an angle of 30~ to the vertical.
The central rib 166 is enlarged at two places. At 161, an
enlargement for a gate dimple is provided. On each side, although only
visible for the inner side 152, there is an enlarged portion 178 with a nail
aperture 180.
In the mounting flange 156, the ribs blend into the main
portion of the mounting flange 156 which has a thickness of 0.25 inches.
An aperture 168 is provided. A tubular reinforcing rivet 170 has a planar
head 172 and a sleeve 174. The bracket 150 would be molded in plastic, as
the earlier embodiments. The rivet 170, as the rivet in the previous
embodiment is intended to protect the plastic from impacts etc.
The channel 158 is preferably tapered, having a width of
- of an inch at the bottom, i.e. where the inclined portion 157 meets the
inner side 152, and a width of 1.125 inches at the top. This is to enable the
bracket to accommodate either 1 inch or - of an inch thick boards.
In use, the inclined portion 157 facilitates insertion of a
board. In particular, for a 1 inch wide board, the board can be slid flush
against the inclined portion 157 and the bracket then tilted, to expand the
channel 158, to accommodate the 1 inch wide board, the sides of the bracket
then being resiliently biassed to clamp the board 60.
Then, the board 60 with an appropriate number of
brackets 150 would be located on the edge of a platform board 58. Each
mounting bracket 150 would be located so that its outer vertical flange 164
abutted the side of the platform board. A nail would then be inserted
through the rivet to secure the bracket in position.
The bracket 150 works similarly with - inch thick boards.
In this case, the bracket would not be expanded significantly or at all.
The brackets of the present invention have numerous
advantages of known mounting techniques, and in particular the bracket
configuration shown in U.S. Patent 3,836,106.
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Thus, in the embodiments described, the channel is
configured to permit easy insertion of the bracket. In the third
embodiment, this is achieved by providing different heights for the sides of
the channel, while in the top mount version of the bracket, the inclined
5 portion at the bottom provides the same function.
The brackets are dimensioned to keep the number of
mounting points to a minimum. One bracket for every 4 foot of length
should be sufficient. The sides of the bracket can be dimensioned to pinch
the toe board of the top, for the side mount version, or at the bottom, for the
10 top mount version.
The brackets rest on sides of the platform boards, adjacent
side edges thereof. The brackets are simply attached by a single nail.
Consequently, the bracket does not interfere with cleats on platform boards.
The bracket itself is not driven on to the platform board, and includes no
15 teeth, serrations or the like which secure the bracket and which would
damage the platform board upon removal. Rather, all that is required is
removal of a single nail. It is conceivable that the brackets can be left
secured to the toe boards.
With regard to overall dimension for the top mounting
20 bracket 150 including ribs and all flanges, it can have an overall height of
758 ~ a length of 3, and an overall width around 4.3 . The mounting flange
120 to the inside of the inner side 116 can be 2.25, with the horizontal outer
flange 162 having a length, as in Figure 10 of 0.5 (the displacement between
the outer flange 164 and outer side 154) and the vertical outer flange 164
25 having a height of 1.125, measured from the top of the horizontal flange
162.
Referring now to Figure 11, this shows a scaffolding
assembly generally indicated by the reference 50. In known manner, the
assembly 50 can include vertical tubes 52, horizontal tubes 54 and
30 appropriate diagonal bracing tubes (not shown). The vertical tubes 52
would include appropriate ground supports (also not shown). Clamping
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brackets 56 secure the various tubes together to form a three dimensional
framework. This can be assembled in known manner, and the exact nature
of the tubes, brackets etc., is not essential to the present invention and any
suitable proprietary scaffolding system can be employed. The horizontal
5 tubes 54 serve to define a horizontal platform. Platform boards 58 are
secured to complete the platform.
Toe board brackets 110 or 150, according to the present
invention, are secured in position by fasteners to the edge of the platform
58. It is expected that nails will be used as fasteners, but it is conceivable that
10 screws or other suitable fasteners can be used, depending upon the
application.
It can be noted that the toe boards are stable even
without fasteners. However, to secure the toe boards 110, 150, particularly to
prevent them from sliding out the ends of the brackets 10, nails 40 are
15 inserted through the apertures in either the inner or the outer sides of the
brackets. Usually the nails 40 will be inserted through one side, and
commonly it will be convenient to insert the nails 40 through the outer side
118 or 154. However, for installations where the scaffolding is located
adjacent to a vertical work surface, e.g. the side of a building, the side of a
20 large storage tank, etc., this may not be possible. In such cases, the nails
would be inserted through the inner side 116 or 152.
The toe boards 60 are then securely held in position. In
particular, impacts from the inside of the toe boards 60, tending to dislodge
them, are absorbed by the nails 40 through the apertures of the mounting
25 flanges. It can be noted that these loads impart a shear load on the nails,
which nails are inherently well adapted to resist.
Consequently, it is virtually impossible for the toe board
60 to be dislodged by normal loads and impacts encountered. Excessive
loads may tend to bend the channel relative to the mounting flange, in
30 either embodiment, but the brackets could be dimensioned to provide a
suitable safety margin over standard loads encountered in use. In contrast,
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in conventional practice, loads on the toe boards tend to impart an axial
load on the nails tending to extract them, which all too often happens,
causing the toe boards to fall off.
The brackets of the present invention have a number of
other advantages. The brackets 110, 150 can be used to join toe boards 60 of
differing, varied and odd lengths. Where long boards are available, brackets
can be spaced at suitable intervals along the length of the board to securely
hold the board in position. A further advantage is that the bracket can
make up for short discrepancies in the length of the boards. Thus, there
could be gap of a few inches between the boards supported by it. Since the
channel has a comparable height to the toe boards, it effectively fills this gapbetween the two toe boards, unlike the proposal in the Gray patent.
The apertures in the inner and outer sides can be
vertically staggered, so that the nails in these apertures do not interfere withone another. They may alternatively be staggered slightly horizontally. For
ease of molding and anticipating that nails will usually be inserted from
just one side,
The exact dimensions for the bracket will depend upon
local regulations, standard sizes of timber locally available, etc. In
particular, the height of the bracket and the height of toe boards may be
subject to local regulations. However, the following dimensions are
~refelled.
The brackets can be dimensioned to accommodate a
variety of plank widths. In particular, they can be dimensioned to accept
and securely hold both - inch and 1 inch thick planks, which are currently
common in the industry in North America.
The side mount version has sharp corners where
required, to ensure close fitting against the edge of a platform board, with no
more than a - inch thick gap. For the top mount version, there should be
no gap. Accordingly, objects of any significant size cannot then be kicked or
accidentally displaced from the platform boards.
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The preferred form of the bracket is molded from a high
strength material, such as glass-filled nylon. It has reinforcing ribs
dimensioned to efficiently transfer applied loads. These ribs blend
smoothly with raised portions providing apertures for nail insertion. For
the critical attachment point to the platform board, the aperture can be
reinforced with a rivet and grommet.
By forming the bracket from a suitable polymer, it can
have a low weight, for example less than- of a pound. This is important on
a construction site. Scaffolding necessarily has to be lifted and raised to great
heights, and then dismantled at the end of a job. Any reduction in weight is
a significant benefit. This also provides adequate chemical, corrosion,
impact and UV resistance. The bracket can be suitably colored, for example
with standard safety yellow color, and can be recyclable.
To remove either embodiment of the bracket, a single
upward thrust towards the deck center is sufficient.
The bracket is wide enough to be used as a splice member.
In other words, the ends of two toe boards can be placed in the bracket and
secured. To this end, two space nail holes are provided on the inner and
outer sides.
The bracket is universal and can be used on any deck
surface. Further, it can be used on all types of scaffolding currently known
to the inventors. More particularly, the top mount version permits
application to some scaffolding designs, for which the side mount version is
impractical.
The bracket can accommodate toe boards of - inch to 1
inch width and from 4- inch to 6 inch height. The bracket could readily be
dimensioned to accept larger toe boards, for example having a 2 inch x 6
inch dimensions.
