Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02821754 2013-07-24
BUILDING ROOF SAFETY ASSEMBLY HAVING A BARRIER AND
LADDER RESTRAINT
FIELD
[0001] This disclosure relates to roof safety assemblies, and more
particularly,
to a safety assembly for placement on a building roof to prevent workers from
falling from that roof and to prevent tipping of ladders used by those workers
to
access that roof.
BACKGROUND
[0002] Workers working on building roofs risk serious injury or even death
in the
event of a fall from that roof or in the event of tipping of a ladder used to
access
that roof. As such, many jurisdictions impose workplace safety rules to govern
conditions for accessing and working on roofs. For example, in Ontario,
Canada,
regulations enacted under the Occupational Health and Safety Act require guard
rails to be installed on a building roof, if the building roof does not have a
parapet of
sufficient height to prevent workers from falling off. Those regulations also
require
the use of devices to secure the top ends of ladders used for roof access, to
prevent falls caused by accidental tipping of those ladders. Similar
requirements
exist in other jurisdictions.
[0003] Various ways of erecting guard rails on roofs are known. For
example,
guard rails may be erected using support posts bolted or otherwise securely
planted into roofs. It is also known to erect guard rails using support posts
that are
each attached to a heavy weight. However, while guard rails protect workers
from
falls while they are on a roof, they do nothing to protect workers from falls
while
they are ascending or descending on ladders used to access that roof. Thus,
any
ladder used to access that roof must be separately secured, as required by
safety
regulations.
[0004] Accordingly, there is a need for improved roof safety apparatuses.
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SUMMARY
[0005] According to an aspect of the present disclosure, there is provided
a
safety assembly for placement on a roof of a building, near an edge of the
roof. The
safety assembly includes a ladder restraint having an opening to receive a
ladder
that provides access to the roof. The opening is sized to restrict left and
right
sideways movement of the ladder when received therethrough. The safety
assembly also includes an upstanding barrier that extends on left and right
sides of
the ladder restraint to block falls by a user. The safety assembly also
includes a
counterweight interconnected with the ladder restraint and the upstanding
barrier
and disposed to prevent forward tipping of the upstanding barrier by the user,
and
to prevent sideways tipping of the ladder during use by the user, when the
safety
assembly is placed on the roof and the ladder is received through the ladder
restraint.
[0006] According to another aspect of the present disclosure, there is
provided a
method of providing access to a roof of a building. The method includes
providing a
ladder restraint attached to a counterweight, the ladder restraint having an
opening
to receive a ladder for accessing the roof, the opening sized to restrict left
and right
sideways movement of the ladder when received therethrough; receiving the
ladder
through the ladder restraint; and counteracting lateral forces on the ladder
during
use by a user, by way of the counterweight, to prevent the forces from tipping
the
ladder.
[0007] According to yet another aspect of the present disclosure, there is
provided a kit for assembling a roof safety assembly, to be placed on a roof
of a
building near its edge. The kit includes a ladder restraint having an opening
for
receiving a ladder, the opening sized to restrict left and right sideways
movement of
the ladder when the ladder is received through the opening; a barrier to block
falls
by a user; and a counterweight, for interconnection with the barrier and the
ladder
restraint, that prevents forward tipping of the barrier by the user when the
counterweight is interconnected with the barrier, and prevents sideways
tipping of
the ladder during use by the user, when the counterweight is interconnected
with
the ladder restraint and the ladder is received through the ladder restraint.
2
[0007a] According to another aspect of the present disclosure, there is
provided a
self-supporting safety assembly for free-standing placement on a roof of a
building, near
an edge of the roof, the safety assembly comprising: a base having a surface
for
placement on the roof, an upstanding barrier that extends generally vertically
from the
base comprising a left upstanding section extending from a left upstanding
post, a right
upstanding section extending from a right upstanding post, and a vertical
opening
therebetween, and a horizontal bar extending between the right upstanding post
and the
left upstanding post, at a height above the base in the vertical opening; a
counter-
weighted ladder restraint extending from the horizontal bar at an angle offset
from
vertical in a direction away from the base, the ladder restraint having an
opening adapted
to receive a ladder resting on the horizontal bar, that provides access to the
roof wherein
the opening is sized so as to restrict left and right sideways movement and
rearward
movement of the ladder received therethrough; and the base comprising a weight
interconnected with the ladder restraint and the upstanding barrier to allow
the self-
supporting safety assembly to be placed on the roof without being affixed
thereto, the
weight disposed at a distance from the ladder restraint and having a mass so
as to
oppose tipping of the upstanding barrier by the user and tipping of the ladder
away from
the roof when received through the ladder restraint, and having portions
located on left
and right sides of the ladder restraint so as to oppose left and right
sideways movement
of the ladder restraint.
[0007b] According to another aspect of the present disclosure, there is
provided a
method of providing access to a roof of a building, the method comprising:
placing a
self-supporting safety assembly on a roof of a building, the self-supporting
safety
assembly comprising a base, a ladder restraint, the ladder restraint having an
opening
to receive a ladder for accessing the roof, the opening sized to restrict left
and right
sideways movement of the ladder when received therethrough, and left and right
upstanding barriers; the base comprising a weight interconnected with the
ladder
restraint and the upstanding barrier to allow the self-supporting safety
assembly to be
placed on the roof without being affixed thereto, the weight disposed at a
distance from
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Date recue/Date Received 2021-01-20
the ladder restraint and having a mass so as to oppose tipping of the ladder
away from
the roof when received through the ladder restraint, and having portions
located on left
and right sides of the ladder restraint so as to oppose left and right
sideways movement
of the ladder restraint; receiving the ladder through the ladder restraint ;
and
counteracting lateral forces on the ladder during use by a user, by way of the
weight, to
prevent the forces from tipping the ladder.
[0007c] According to another aspect of the present disclosure, there is
provided a
kit for assembling a roof safety assembly, to be placed on a roof of a
building near its
edge, the kit comprising: a ladder restraint having an opening for receiving a
ladder, the
opening sized to restrict left and right sideways movement of the ladder when
the ladder
is received through the opening; an upstanding barrier that extends generally
vertically,
the upstanding barrier comprising a left upstanding section comprising a left
vertical post
section, a right upstanding section comprising a right vertical post section,
and a vertical
opening therebetween, and further comprising a horizontal bar extending
between the
right vertical post section and the left vertical post section, for supporting
the ladder
restraint; and a counterweight, for interconnection with the upstanding
barrier and the
ladder restraint, that prevents tipping of the upstanding barrier by the user
when the
counterweight is interconnected with the barrier, and prevents sideways
tipping of the
ladder during use by the user, when the counterweight is interconnected with
the ladder
restraint and the ladder is received through the ladder restraint.
[0007d] According to another aspect of the present disclosure, there is
provided a
self-supporting safety assembly for free standing placement on a roof of a
building, near
an edge of the roof, the safety assembly comprising: a base having a surface
for
placement on the roof; an upstanding barrier that extends generally vertically
from the
base, the upstanding barrier comprising a left upstanding section extending
from a left
upstanding post, a right upstanding section extending from a right upstanding
post, and
a vertical opening therebetween, and further comprising a horizontal bar
extending
between the right upstanding post and the left upstanding post, at a height
above the
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Date recue/Date Received 2021-01-20
base in the vertical opening; a counter-weighted ladder restraint extending
from the
horizontal bar at an angle offset from vertical, in a direction away from the
base, the
ladder restraint having an opening adapted to receive a ladder extending
therethrough
when resting on the horizontal bar to provide access to the roof wherein the
opening is
sized so as to restrict left and right sideways and rearward movement of the
ladder
received therethrough; wherein gaps between the ladder restraint and the left
post and
the right post allow a user to climb from the ladder onto the roof when the
safety
assembly is placed on the roof; the base comprising a weight interconnected
with the
ladder restraint and the upstanding barrier to allow the self-supporting
safety assembly
to be placed on the roof without being affixed thereto, the weight disposed at
a distance
from the ladder restraint and the upstanding barrier and having a mass so as
to oppose
tipping of the upstanding barrier by the user and tipping of the ladder away
from the roof
when received in the ladder restraint, and having portions located on left and
right sides
of the ladder restraint so as to oppose left and right sideways movement of
the ladder
restraint.
[0007e]
According to another aspect of the present disclosure, there is provided a
self-supporting safety assembly for free-standing placement on a roof of a
building, near
an edge of the roof, the safety assembly comprising: a base having a surface
for
placement on the roof, an upstanding barrier that extends generally vertically
relative to
the base comprising a left upstanding section comprising a left vertical post
section, a
right upstanding section comprising a right vertical post section, and a
vertical opening
therebetween, and a horizontal bar extending between the right vertical post
section and
the left vertical post section, at a height above the base in the vertical
opening; a counter-
weighted ladder restraint extending from the horizontal bar at an angle offset
from
vertical in a direction away from the base, the ladder restraint having an
opening adapted
to receive a ladder resting on the horizontal bar, that provides access to the
roof wherein
the opening is sized so as to restrict left and right sideways movement and
rearward
movement of the ladder received therethrough; and the base comprising a weight
interconnected with the ladder restraint to allow the self-supporting safety
assembly to
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Date recue/Date Received 2021-01-20
be placed on the roof without being affixed thereto, the weight disposed at a
distance
from the ladder restraint and having a mass so as to oppose tipping of the
upstanding
barrier by the user and tipping of the ladder away from the roof when received
through
the ladder restraint, and having portions located on left and right sides of
the ladder
restraint so as to oppose left and right sideways movement of the ladder
restraint.
2d
Date recue/Date Received 2021-01-20
CA 02821754 2013-07-24
[0008] Other features will become apparent from the drawings in conjunction
with the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the figures which illustrate example embodiments,
[0010] FIG. 1 is a rear perspective view of a roof safety assembly,
exemplary of
an embodiment;
[0011] FIG. 2 is a front elevation view of the roof safety assembly of FIG.
1;
[0012] FIG. 3 is a rear perspective view of a fitting used to interconnect
guard
rail members of the roof safety assembly of FIG. 1;
[0013] FIG. 4 is a rear perspective view of another fitting used to
interconnect
guard rail members of the roof safety assembly of FIG. 1;
[0014] FIG. 5 is a rear perspective view of a fitting used to mount a
ladder
restraint of the roof safety assembly of FIG. 1;
[0015] FIGS. 6A, 6B, 6C and 6D are each front elevation views of a ladder
restraint of the roof safety assembly of FIG. 1, exemplary of four
embodiments,
respectively;
[0016] FIG. 7 is a right elevation view of the roof safety assembly of FIG.
1;
[0017] FIG. 8 is a top plan view of the roof safety assembly of FIG. 1;
[0018] FIG. 9 is a top plan view of the roof safety assembly of FIG. 1 with
its
weighted elements exposed;
[0019] FIG. 10 is a is a rear perspective view of a roof safety assembly,
exemplary of another embodiment;
[0020] FIG. 11 is a is a rear perspective view of a roof safety assembly,
exemplary of yet another embodiment;
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[0021] FIG. 12 is a rear perspective view of the roof safety assembly of
FIG. 1
during operation; and
[0022] FIG. 13 is a right elevation view of the roof safety assembly of
FIG. 1
during operation.
DETAILED DESCRIPTION
[0023] FIG. 1 depicts a roof safety assembly 10, exemplary of an
embodiment.
As will become apparent, roof safety assembly 10, when placed on a
substantially
flat or gently sloping building roof near an edge of that roof, protects
workers from
falls from that roof, and also protects workers from falls caused by
accidental
tipping of a ladder used to access that roof. As such, roof safety assembly 10
may
be placed on building roofs that otherwise lack fall protection features or
require
existing safety features to be supplemented, to protect workers who work on
and
access those roofs.
[0024] Roof safety assembly 10 includes a ladder restraint 12 having an
opening
14 for receiving a ladder. A ladder received through opening 14 is secured
from
accidental tipping, as detailed below. Roof safety assembly 10 also includes
upstanding barriers 16A and 16B for blocking falls by a worker. Barriers 16A
and
16B are erected to extend on either side of ladder restraint 12, along at
least one
edge of roof safety assembly 10. Roof safety assembly 10 also includes base 18
that supports roof safety assembly 10 on a roof, and provides a flat working
surface. As will be detailed below, base 18 includes a counterweight that both
prevents a worker from tipping barriers 16A and 168 towards a roof edge, and
prevents sideways tipping of a ladder secured by ladder restraint 12 while a
worker
uses that ladder.
[0025] As noted, roof safety assembly 10 includes upstanding barriers 16A
and
16B to block falls, e.g., by a worker on base 18. As such, upstanding barriers
16A
and 16B are fixedly mounted to base 18, and are sized to extend along one side
of
base 18 at a height sufficient to block passage of a worker. The height of
each of
barriers 16A and 16B in the depicted embodiment is approximately 3-1/2 feet.
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However, as will be appreciated, this height may be changed in other
embodiments
to suit particular roof setting and/or suit particular safety requirements,
which may
vary from jurisdiction to jurisdiction.
[0026] In the depicted embodiment, barriers 16A and 168 each take the form
of
guard rails. However, in other embodiments, one or both of barriers 16A and
16B
may be replaced with fences, walls, or any combination of fences, walls,
rails, or
the like, suitable to block passage of a worker.
[0027] As depicted in FIG. 2, barrier 16A includes a top horizontal rail
member
20A and a mid horizontal rail member 22A that extend along the length of
barrier
16A. Horizontal rail members 20A and 22A are attached to posts 24A, 26A and
28A using a plurality of 90-degree cross-over fittings 40 (e.g., as shown in
FIG. 3).
Barrier 16A extends from an end proximate ladder restraint 12 to an opposite
end
terminated by a left-handed 0-return formed by attaching vertical rail member
30A
to horizontal rail members 20A and 22A using two 90-degree elbow fittings 42
(e.g.,
as shown in FIG. 4). Each of posts 24A, 26A, and 28A are respectively attached
to
base 18 using three socketed flanges 46.
[0028] Barrier 16B extends on the side of ladder restraint 12 opposite
barrier
16A. In the depicted embodiment, barrier 16B is symmetrical to barrier 16A
about a
vertical plane that bisects ladder restraint 12. Similar to barrier 16A,
barrier 16B
includes a top horizontal rail member 20B and a mid horizontal rail member 22B
that extend along the length of barrier 16B. Horizontal rail members 20B and
22B
are attached to posts 24B, 26B and 28B using a plurality of 90-degree cross-
over
fittings 40.
[0029] The end of barrier 16B opposite ladder restraint 12 is terminated by
a
right-handed D-return formed by attaching vertical rail member 30B to
horizontal
rail members 20B and 22B using two 90-degree elbow fittings 42.
[0030] In the depicted embodiment, each of the rail members and posts of
barriers 16A and 16B are substantially cylindrical in shape. In other
embodiments,
these rail members and/or posts could have other shapes providing structural
strength sufficient to meet safety requirements.
CA 02821754 2013-07-24
[0031] As best seen in FIG. 3, a 90-degree cross-over fitting 40 includes two
hollow cylindrical portions 50 and 52, oriented at right angles to each other.
Cylindrical portion 50 has an inner diameter complementary to the diameter of
horizontal rail member 20A/B and 22A/B, while cylindrical portion 52 has an
inner
diameter complementary to the diameter of posts 24A/B, 26A/B and 28A/B. By
way of example, FIG. 3 illustrates the use of a 90-degree cross-over fitting
40 to
attach horizontal rail member 20A to post 28A. As depicted, horizontal rail
member
20A is inserted through cylindrical portion 50 and fastened therein using a
grub
screw 54. Meanwhile, post 28A is inserted through cylindrical portion 52 and
fastened therein using another grub screw 54.
[0032] Each grub screw 54 may be a conventional grub screw, and may be
formed from case-hardened steel or a like material. Each grub screw 54
includes a
socket such as, for example, a hexagon socket to permit tightening/loosening
by a
conventional hexagonal key.
[0033] The use of 90-degree cross-over fitting 40 elsewhere in roof safety
assembly 10 follows the example shown in FIG. 3, and is not further detailed
herein.
[0034] As best seen in FIG. 4, a 90-degree elbow fitting 40 includes two
socketed portions 56 and 58, oriented at right angles to each other. Socketed
portion 58 has an inner socket diameter complementary to the diameter of
vertical
rail members 30A/B, while socketed portion 56 has an inner socket diameter
complementary to the diameter of horizontal rail member 20A/B and 22A/B. By
way
of example, FIG. 4 illustrates the use of a 90-degree elbow fitting 40 to
attach
horizontal rail member 20A to vertical rail member 30A. As depicted,
horizontal rail
member 20A is inserted into socketed portion 66 and fastened therein using a
grub
screw 54, while vertical rail member 30A is inserted into socketed portion 58
and
fastened therein using another grub screw 54.
[0035] The use of 90-degree elbow fitting 40 elsewhere in roof safety
assembly
follows the example shown in FIG. 4 and is not further detailed herein.
[0036] Upstanding barriers 16A and 16B are spaced to provide a gap
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therebetween to allow ingress/egress by a worker using a ladder positioned
proximate to that gap, and to mount ladder restraint 12 for securing that
ladder. As
such, barriers 16A and 16B are spaced to provide a gap of sufficient width to
allow
a worker to step off the ladder received in ladder restraint 12 on to base 18,
and to
allow a worker to climb on to on to the ladder from base 18. In the depicted
embodiment, the gap between barriers 16A and 16B is approximately 5 feet in
width, but this width may be adjusted in other embodiments to suit particular
roof
settings and particular safety requirements.
[0037] Further, in the depicted embodiment, ladder restraint 12 is mounted
centrally between barriers 16A and 16B such that a worker may ingress/egress
from either the left side or the right side of a ladder received in ladder
restraint 12.
Conveniently, workers may elect to ingress/egress from one side or the other
based
on their handedness. In other embodiments, ladder restraint 12 may be mounted
to
be next to barrier 16A or 16B, and thus allow workers to ingress/egress on
only one
side (i.e., the left side or the right side) of a ladder received in ladder
restraint 12.
[0038] As depicted, the gap between 16A and 16B is bridged by a horizontal bar
32 for mounting ladder restraint 12. In the depicted embodiment, horizontal
bar 32
is substantially cylindrical in shape. Horizontal bar 32 is attached to post
24A of
barrier 16A and to post 24B of barrier 16B using two 90-degree cross-over
fittings
40, in a manner similar to that shown in FIG. 3.
[0039] In some embodiments, horizontal bar 32 may be mounted at a height
that
allows a ladder to be rested against bar 32 without contacting the edge of a
roof,
the edge of roof parapet, and/or roof fixtures such as, e.g., an eavestrough.
Conveniently, this prevents those edge and/or fixtures from being damaged by a
ladder rested thereagainst, or otherwise makes contact therewith. Similarly,
resting
a ladder against roof features that would not provide stable support for a
ladder,
such as, e.g., curved edges or canted edges of roofs or parapets may be
avoided.
In other embodiments, horizontal bar 32 may be mounted at a height that allows
a
ladder received in ladder restraint 12 to be rested on the edge of a roof or
roof
parapet.
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[0040] Ladder restraint 12 of roof safety assembly 10 is used to secure a
ladder
used to access a building roof. Ladder restraint 12 is shaped to define an
opening
14 for receiving a ladder, with opening 14 sized to secure a ladder received
therethrough. In particular, opening 14 is sized to restrict left and right
sideways
movement of a ladder received therethrough. Ladder restraint 12 may, for
example,
comprise two parallel posts spaced to provide opening 14. In some embodiments,
ladder restraint 12 may be shaped to encircle a ladder at least partially, to
prevent
the ladder from tipping backwards out of opening 14. Ladder restraint 12 may
also
be shaped to encircle a ladder completely, e.g., ladder restraint 12 may be U-
shaped or hoop-shaped, or the like. In the depicted embodiment, ladder
restraint 12
is shown to be formed from separate components, but ladder restraint 12 could
also
be formed as a unitary body in other embodiments.
[0041] As depicted in FIG. 6A, ladder restraint 12 is formed using posts 34A
and
348 and bar 36, each of which is substantially cylindrical in shape.
Specifically,
ladder restraint 12 is formed by attaching bar 36 to posts 34A and 34B using
two
90-degree elbow fittings 42, in a manner similar to that shown in FIG. 4.
[0042] Ladder restraint 12 is mounted to horizontal bar 32 by attaching
posts
34A and 34B to horizontal bar 32 using respective tee fittings 44. As best
seen in
FIG. 5, a tee fitting 40 includes a hollow cylindrical portion 60 oriented at
a right
angle to socketed portion 62. Cylindrical portion 60 has an inner diameter
complementary to the diameter of horizontal bar 32, while socketed portion 62
has
an inner socket diameter complementary to the diameter of posts 34A/B. As
depicted, horizontal bar 32 is inserted through cylindrical portion 60 and
fastened
therein using a grub screw 54, while post 34A is inserted into socketed
portion 62
and fastened therein using another grub screw 54. The opposite end of
horizontal
bar 32 is secured to post 34B using another tee fitting 40, in a similar
manner.
[0043] Once ladder restraint 12 is mounted, posts 34A/B, bar 36 and bar 32
define opening 14 for receiving a ladder therethrough. As such, post 34A and
34B
are spaced far enough apart to make opening 14 wide enough to receive a
ladder.
At the same time, posts 34A and 34B are spaced close enough together to
restrict
left and right sideways movement of that ladder when it is received through
opening
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14. In the depicted embodiment, posts 34A and 34B are spaced to make opening
14 approximately 21 inches wide. However, in other embodiments, posts 34A and
34B may be spaced closer together or farther apart to accommodate ladders of
different widths, and may vary according to regulations governing the width of
ladders used in particular jurisdictions.
[0044] As will be appreciated, when a ladder is received through opening 14 of
ladder restraint 12, bar 36 that extends along the top of opening 14 serves to
prevent the ladder from tipping backwards out of opening 14.
[0045] FIG. 6B depicts ladder restraint 112, according to an embodiment in
which bar 36 of ladder restraint 12 is omitted. Such an embodiment may be
suitable
for use in settings where backwards tipping of a ladder is not a concern.
Omitting
bar 36 allows a ladder to be lowered into the opening of the ladder restraint
from
above the ladder restraint. This facilitates ready placement of a ladder into
the
opening of the ladder restraint, even in settings where view of the opening
from the
ground is partly or fully occluded, e.g., by obstructions below a roof
parapet. In such
embodiments, the two 90-degree elbow fittings 42 used to attach posts 34A and
34B to bar 36 may be replaced with plugs 38 to terminate the top ends of posts
34A and 34B.
[0046] FIG. 6C depicts ladder restraint 212, according to a yet another
embodiment. Like ladder restraint 112 (FIG. 6B), ladder restraint 212 does not
include bar 36 of ladder restraint 12. However, as depicted, ladder restraint
212
includes a bar 37 that extends between posts 34A and 34B. Bar 37 is mounted to
posts 34A and 34B using respective tee fittings 44 at a height that allows a
ladder
to be rested against bar 37 without contacting the edge of a roof, the edge of
roof
parapet, roof fixtures that might be damaged such as, e.g., eavestroughs,
and/or
roof features that would not provide stable support for a ladder such as,
e.g.,
curved edges or canted edges. As will be appreciated, bar 37 is mounted at a
height sufficiently below the top ends of posts 34A and 34B to allow a ladder
to be
securely retained between posts 34A and 34B.
[0047] FIG. 6D depicts ladder restraint 312, according to yet another
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embodiment. As depicted, ladder restraint 312 includes both bar 37, which
provides
a support against which a ladder may be rested, and bar 36, which prevents the
ladder from tipping backwards out of ladder restraint 312.
[0048] As best seen in FIG. 7, ladder restraint 12 is mounted on horizontal
bar
32 to extend away from barriers 16A/B, such that, when roof safety assembly 10
is
placed on a roof near an edge of that roof, ladder restraint 12 extends in a
direction
towards that edge. Further, ladder restraint 12 is mounted on horizontal bar
32 at
an angle offset from upstanding barriers 16A/B. In the depicted embodiment,
this
angle is approximately 450. In other embodiments, ladder restraint 12 may be
mounted on horizontal bar 32 with this angle at 0 , i.e., such that ladder
restraint 12
is parallel to upstanding barriers 16A/B. In yet other embodiments, this angle
may
be between 0 and 90 , and may be selected to accommodate roofs of different
heights, as well as roof parapets of different heights and widths. Mounting
ladder
restraint 12 at such an angle facilitates ready insertion of a ladder through
opening
14 of ladder restraint 12 during operation.
[0049] In some embodiments, ladder restraint 12 may be mounted directly to
base 18, such that horizontal bar 32 may be omitted.
[0050] The bottom end of each of posts 24A/B, 26A/B, and 28A/B is inserted
into a corresponding socketed flange 46 to attach the posts to base 18. The
posts
are secured to socketed flanges 46, e.g., using grub screws. Socketed flanges
46
are in turn secured to elongate support members 64A/B, 66A/B, and 68A/B of
base
18 (FIG. 8), e.g., also using grub screws. As depicted, in this way, each of
posts
24A/B, 26A/8, and 28A/B is attached to a corresponding one of elongate support
members 64A/B, 66A/B and 68A/B. The bottom end of each socked flanges 46
includes a spread plate 48 for distributing the weight of roof safety assembly
10,
including the weight of barriers 16A and 16B, over an area of a roof under the
spread plate 48, when roof safety assembly 10 is placed on that roof.
Conveniently,
use of spread plates 48 helps to prevent the roof from being damaged by point
loads. In the depicted embodiment, spread plate 48 is a rectangular plate
approximately 6"x12" in size. However, in other embodiments, the size and
shape
of spread plate 48 may be changed.
CA 02821754 2013-07-24
[0051] Together, barriers 16A and 16B and the gap therebetween span the
length of base 18, with the D-returns at the far ends of barriers 16A and 16B
extending slightly past the right and left edges of base 18. In the depicted
embodiment, the total span of barrier 16A and 16B and the gap therebetween is
approximately 20 feet. However, the span of barriers 16A/16B may be increased
by
extending horizontal bars 20A/B and 22A/B. Further, additional posts alike to
posts
24A/B-28A/B may be added to support the extended horizontal bars. Conversely,
the span of barriers 16A/B may be decreased by shortening horizontal bars
20A/B
and 22A/B, and removing one or more of posts 24A/B-28A/B as necessary. The
heights of each of barriers 16A and 16B may be changed in other embodiments by
increasing or decreasing the lengths of post 24A/B-28A/B.
[0052] Each of the rails members and post forming barriers 16A/B, each of the
bars and posts forming ladder restraint 12, as well as horizontal mounting bar
36,
may be hollow tubing or solid bars formed from metal such as iron, steel,
aluminum,
or the like. These components may be formed by casting. For resistance to
rusting,
components formed from stainless steel, aluminum or galvanized metal may be
used. In some embodiments, these components may be made from high-stiffness
plastics such as, for example, fiberglass-reinforced plastic. Such plastic
components may be formed from conventional, molding or extrusion/pultrusion
processes. Some or all of these components may be sized to have a
diameter/width suitable for gripping, e.g., approximately 1-2 inches.
[0053] Fittings and flanges of roof safety assembly 10, described above,
may be
formed from materials similar to the rail members, bars and posts, such as,
for
example, cast iron or cast aluminum, or any other suitable alloy or stiff
plastic.
[0054] Although grub screws are used to interconnect components of roof safety
assembly 10 in the depicted embodiment, other ways to fasten these components
may be used in other embodiments. For example, components (e.g., a rail member
and a fitting) may be fastened together using bolts, rivets, pins, etc. In
some
embodiments, rail members may be fastened to fittings by way of crimping. In
yet
other embodiments, rail members may fastened to other rail members directly
(e.g.,
by welding) such that some or all of the fittings may be avoided. Yet other
suitable
11
CA 02821754 2013-07-24
ways to interconnect components of roof safety assembly 10 will be readily
apparent to those skilled in the art.
[0055] Further, although barrier 16A and 16B are terminated by respective D-
returns in the depicted embodiment, in other embodiments, one or both of
barriers
16A and 16B may simply be terminated by plugs inserted into the ends of
horizontal rail members 20A/B and 22A/B. In yet other embodiments, one or both
of barriers 16A and 16B may be terminated by flanges suitable for affixing
barrier
16A116B to a wall.
[0056] As noted, roof safety assembly 10 includes base 18 to support roof
safety
assembly 10 on a roof and to provide a flat working surface. Further, base 18
includes a counterweight that prevents upstanding barriers 16A/16B from being
tipped towards a roof edge by a worker, and also prevents sideways tipping of
a
ladder received in ladder restraint 12 while a worker is using the ladder. To
this
end, base 18 includes a plurality of weighted elements that have sufficient
mass
and that are positioned to provide this counterweight, as detailed below.
[0057] Base 18 includes a plurality of elongate support members 64A/B,
66A/B,
and 68A/B, which extend from barriers 16A/16B towards the back of roof safety
assembly 10. Collectively, elongate support members 64A1B, 66A/B, and 68A/B
serve to support roof safety assembly 10 on a roof surface.
[0058] As depicted in FIGS. 1 and 8, the top surface of base 18 is covered
with
four panels 70 and a panel 72. Panels 70 and 72 are substantially rectangular
in
shape and rest in between elongate support members 64A/B, 66A/B, and 68A/B
on recessed support rails extending along those elongate support members, as
detailed below. Panels 70 and 72 and elongate support members 64A/B, 66A/B,
and 68A/B collectively form a substantially flat working surface, on which
workers
can walk.
[0059] Panels 70 and 72 may be formed from stiff plastic, such as, for
example,
fiberglass-reinforced plastic, formed from conventional molding or
extrusion/pultrusion processes. As depicted, panels 70 and 72 may be
perforated
to form a grating. This reduces the weight of panels 70 and 72, facilitates
water and
12
CA 02821754 2013-07-24
snow run-off, and may improve traction. Conveniently, snow that falls through
the
grating may rest directly on the roof instead of accumulating on roof safety
assembly 100. This may reduce localized loading of the roof by roof safety
assembly 100, e.g., at spreader plates 48. In some embodiments, panels 70 and
72
may be formed from materials adapted to prevent slipping. In some embodiments,
panels 70 and 72 may be formed from UV-protected materials adapted to prevent
UV degradation. In the depicted embodiment, panels 70 and 72 are approximately
1 inch thick. In other embodiments, the thickness of panels 70 and 72 be
increased
or decreased. In some embodiments, panels 70 and 72 may, for example, be
Fibergrate (TM) molded plastic grating distributed by Fibergrate Canada of
Ontario,
Canada.
[0060] FIG. 9 depicts roof safety assembly 10 with panels 70 and 72 removed.
Removal of 70 and 72 exposes the aforementioned support rails extending along
elongate support members 64A/B, 66A/B, and 68A/B, namely, support rails 74
which extend along right side of each of the support members and support rails
76
which extend along the left side of the support members. Support rails 74 and
76
are recessed from the top surface of support members 64A/B, 66A/B, and 68A/B
at a depth corresponding to the thickness of panels 70 and 72 (e.g., 1 or more
inches), and extend along substantially the entire length of elongate support
members 64A/B, 66A/B, and 68A/B.
[0061] FIG. 9 also depicts four weighted elements 78 and a weighted element
80 disposed at the rear of base 18. Weighted elements 78 and 80 are
substantially
rectangular in shape, and are sized to fit between support members 64A/B,
66A/B,
and 68A/B, where they are supported by support rails 74 and 76. In some
embodiments, weighted elements 78 and 80 may be securely fastened to support
rails 74 and 76 and/or support members 64A/B, 66A/B, and 68A/B.
[0062] Weighted elements 78 and 80 are formed from material substantially
heavier than panels 70 and 72. In the depicted embodiment, each of weighted
elements 78 and 80 is formed from metal plates. Collectively, weighted
elements 78
and 80 form a counterweight that serves to prevent tipping of upstanding
barriers
16A/16B towards a roof edge by a worker. As will be appreciated, the tipping
point
13
CA 02821754 2013-07-24
of upstanding barriers 16A/16B is located at their base, along the forward
edge of
roof safety assembly 10. Thus, forming a counterweight at the rear of roof
safety
assembly 10 at a set distance from this tipping point greates a load moment
that is
proportional to this distance and the mass of the counterweight, which
counteracts
loads created by tipping of upstanding barriers 16A/16B by a worker.
Conveniently,
weighted elements 78 and 80 also serve to prevent tipping of a ladder away
from a
roof when that ladder is received in ladder restraint 12.
[0063] At the same time, the counterweight formed from weighted elements 78
and 80 also serves counteract lateral forces on a ladder to prevent sideways
tipping
of the ladder while a worker is using it, e.g., as caused by weight or
movement of a
worker on the ladder, slipping of the ladder along a building edge or parapet,
unstable or uneven ladder footing, improper placement of a ladder against a
building wall, wind, etc. In this situation, the tipping point is located at
ladder
restraint 12. Thus, forming a counterweight having portions located laterally
away
from ladder restraint 12 to its left and right sides creates load moments that
are
proportional to the left/right lateral distance between ladder restraint 12
and those
portions of the counterweight. This counteracts loads created by left or right
sideways tipping of a ladder secured in ladder restraint 12.
[0064] Conveniently, providing a counterweight as shown allows roof safety
assembly 10 to be installed on a roof by merely placing roof safety assembly
10 on
the roof. As such, there is no need to drill into or otherwise penetrate the
roof,
which may breach the roof's waterproofing membrane or otherwise damage the
roof.
[0065] Further, forming a counterweight that extends along substantially
the
entire length of roof safety assembly 10, as depicted, serves to distribute
the
downward load of the counterweight over a larger roof area. This reduces
localized
loads on the roof, which may be desirable if the roof is not designed to
support
loads substantially beyond normal snow loads.
[0066] Although the depicted embodiment includes a counterweight formed from
metal plates, other suitable weighted elements may also be used. For example,
the
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CA 02821754 2013-07-24
weighted elements need not be formed from metal, but may be formed from other
materials, such as concrete, stone, ceramic, sand, rubber, plastic, or the
like, or
combinations thereof. In some embodiments, the weighted elements may be
formed from recycled materials, such as, e.g., recycled rubber, plastic, or
the like.
Yet other materials having density suitable for forming weighted elements will
be
readily apparent to those skilled in the art. Further, the number of weighted
elements could vary, so long as the total mass of the weighted elements is
sufficient to serve as a counterweight, as described above.
[0067] This total mass of the weighted elements may be varied to suit
particular
roof settings and particular safety requirements, and may also be varied based
on
the distance of the counterweight to the above-discussed tipping points. In
the
depicted embodiment, the four weighted elements 78 and weighted element 80
have a combined mass of approximately 115 kg.
[0068] Of course, the total mass of weighted elements 78 and 80 should be
selected taking into account the mass of other components of roof safety
assembly
which may also function as part of the counterweight, such as, for example,
panels 70 and 72, and elongate support members 64A/B, 66A/B, and 68A/B.
[0069] FIG. 10 depicts roof safety assembly 100, according to another
embodiment, with base 18 replaced with base 118. As depicted, in this
embodiment, the top surface of base 118 is partly covered with four panels 92
and
a panel 94. Unlike panels 70 and 72 of base 18, panels 92 and 94 of base 118
do
not extend from barriers 16A/16B all the way to the back edge of the base.
Rather,
panels 92 and 94 terminate near the back of base 118 where panels 92 and 94
meet a row of weighted elements 90. Panels 92 and 94 may be alike to panels 70
and 72 in other aspects, e.g., panels 92 and 94 may be formed from the same
materials as panels 70 and 72, as discussed above.
[0070] Like weighted elements 78 and 80 of roof safety assembly 10,
weighted
elements 90 are supported by support rails 74 and 76. Weighted elements 90 are
also supported by additional support members (not shown) which extend
perpendicularly to support rails 74 and 76 underneath weighted elements 90 and
CA 02821754 2013-07-24
are attached to elongate support members 64A/B, 66A/B, and 68A/B.
[0071] Unlike weighted elements 78 and 80 of roof safety assembly 10,
weighted elements 90 are not covered by panels. Rather, weighted elements 90
are coplanar with panels 92 and 94; weight elements 90 and panels 92/94
collectively form a substantially planar working surface, on which workers can
walk.
As such, weighted elements 90 have a substantially flat top surface and are
adapted to support workers thereon. Further, weighted elements 90 are formed
from material substantially heavier than panels 92 and 94. In the depicted
embodiment, each weighted element 90 is a concrete paving slab. In other
embodiments, these concrete paving slabs may be replaced with other suitable
weighted elements.
[0072] Further, unlike weighted elements 78 and 80 of roof safety assembly
10,
which are contained in the space within base 18 below panels 70 and 72,
weighted
elements 90 of roof safety assembly 100 extend to the top surface of base 118.
As
such, weighted elements 90 of roof safety assembly 100 can be larger, and
therefore more massive than weighted elements 78 and 80 of roof safety
assembly
10. In the depicted embodiment, each of the concrete paving slabs used as a
weighted element 90 has a mass of approximately 20 kg. Accordingly, the
combined mass of the eleven concrete paving slabs of roof safety assembly 100
is
approximately 220 kg, which is approximately twice the total mass of the
weighted
elements of roof safety assembly 10.
[0073] As will be appreciated, weighted elements 90 of roof safety assembly
100
form a counterweight that functions in substantially the same manner as the
counterweight discussed above for roof safety assembly 10. As before, the
counterweight formed from weighted elements 90 is located at a distance behind
barriers 16A/16B and ladder restraint 12, and thereby prevents tipping of
barriers
16A/16B off of a roof and tipping of a ladder secured in ladder restraint 12
away
from the roof. Further, as before, this counterweight extends laterally to the
left and
right of ladder restraint, and thereby prevents left and right sideways
tipping of a
ladder secured in ladder restraint 12.
16
CA 02821754 2013-07-24
[0074] FIG. 11 depicts roof safety assembly 200, according to a further
embodiment, with base 18/118 replaced with base 218. As depicted, in this
embodiment, the top surface of base 218 is substantially covered with weighted
elements 90, arranged to form a substantially planar working surface, on which
workers can walk. As such, the panels of safety assemblies 10 and 100 may be
omitted.
[0075] As in roof safety assembly 100, weighted elements 90 of roof safety
assembly 200 are supported by support rails 74 and 76. They are also supported
by additional support members (not shown) which extend perpendicularly to
support rails 74 and 76 underneath weighted elements 90 and are attached to
elongate support members 64A/B, 66A/B, and 68NB.
[0076] In the depicted embodiment, each weighted elements 90 of roof safety
assembly 200 is a concrete paving slab, having a mass of approximately 20 kg.
The combined mass of weighted elements 90 of roof safety assembly 200 is
therefore approximately 660 kg. As such, roof safety assembly 200 may be used
in
situations calling for additional counterweight.
[0077] In yet other embodiments, elongate support members 64A/B, 66A/B, and
68A/B may, by themselves, have sufficient mass to form the counterweight
described above. To this end, elongate support members 64A/B, 66A/B, and
68A/B may be made formed from or include any of the materials described above
for forming weighted elements. In such embodiments, no additional weighted
elements are required.
[0078] FIGS. 12 and 13 depict roof safety assembly 10 in operation. As
depicted, roof safety assembly 10 is assembled on roof 300 of a building near
an
edge 302 to protect falls by a worker working on or accessing roof 300. In
particular, base 18 is placed on roof 300, and ladder restraint 12 and
barriers
16A/B are attached to base 18. As depicted, barriers 16A/B extend
substantially
parallel to edge 302 on left and right sides of ladder restraint 12. As worker
500
moves on top of base 18, the counterweight of base 18 prevents worker 500 from
tipping barriers 16A/B off roof 300. Thus, roof safety assembly 100 protects
worker
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CA 02821754 2013-07-24
500 from falling off of roof 300.
[0079] Further, as depicted, a portable ladder 400 is used to access roof
300.
Ladder 400 is received through opening 14 of ladder restraint 12. Meanwhile,
ladder 400 is erected to rest against the building at edge 302, at an angle of
approximately 75 from vertical in accordance with conventional safety
practices.
With ladder 400 received through opening 14, the counterweight of base 18
prevents ladder 400 from tipping while worker 500 is using it. In this way,
roof
safety assembly 100 protects worker 500 from falling when using ladder 400 to
access roof 300.
[0080] Conveniently, ladder restraint 12 may be adapted in the field to
suit
particular roof and roof parapet configurations. For example, the position of
ladder
restraint 12 may be adjusted up or down by changing the height at which
horizontal
bar 32 is attached to posts 34A and 34B. Further, the angle at which ladder
restraint 12 is offset from upstanding barriers 16A/B may be adjusted by
changing
the angle at which tee fittings 44 are secured to horizontal mounting bar 32.
The
position and the angle of ladder restraint 12 may be adjusted to allow ladder
restraint 12 to receive a ladder, while accommodating roofs of different
heights, as
well as roof parapets of different heights and widths. Furthermore, the height
of
horizontal bar 32 may be adjusted in the field such that a ladder may be
rested
against it. Similarly, ladder restraint 12 could be modified in the field to
include a bar
37 (FIGS. 6C/6D) mounted to posts 34A and 34B at a height to allow a ladder to
be
rested against bar 37. In these ways, a ladder received in ladder restraint 12
may
be offset from a roof edge, a parapet edge, roof fixtures, and/or a roof
features, as
desired.
[0081] Conveniently, embodiments of the roof safety assembly described
herein
allow portable ladders such as, e.g., a conventional extension ladder, to be
used to
access a roof, even when safety regulations require the tops ends of ladders
to be
secured prior to use. Accordingly, certain drawbacks associated with
installation of
permanent ladders may be avoided, such as, for example, vulnerability of
permanent ladders to vandalism or weather damage, and the risk of unauthorized
access to roofs. Further, use of portable ladders leaned at an angle, as
provided
18
CA 02821754 2013-07-24
herein, also avoids the need to comply with government safety regulations that
specifically govern the use of vertical ladders.
[0082] Conveniently, the modular design of embodiments of the roof safety
assembly facilitates ready transport of components to and from building roofs,
and
assembly and disassembly in situ. As such, embodiments of the roof safety
assembly may be distributed in the form of kits, with components of the roof
safety
assembly unassembled or partially assembled. Such kits may be assembled on a
roof of a building to provide a roof safety assembly for use in manners
described
herein.
[0083] Of course, the above described embodiments are intended to be
illustrative only and in no way limiting. The described embodiments are
susceptible
to many modifications of form, arrangement of parts, details and order of
operation.
The invention, rather, is intended to encompass all such modification within
its
scope, as defined by the claims.
19
