Note: Descriptions are shown in the official language in which they were submitted.
CA 02505050 2005-04-22
Agent File No. 272.3
TITLE: VARIABLE RAIL SAFETY SYSTEM
s FIELD OF THE INVENTION
The present invention relates to a safety device and more particularly to a
temporary, multi-use guard rail system to provide a safe working area for
persons on a building under construction.
1o BACKGROUND OF THE INVENTION
When a residential or commercial building is in the various stages of
construction, there is a need to have a safe work area. There have been
problems providing safety rails to areas under construction such as floor
edges,
roof edges, and tops of walls as they are being erected prior to the floor
being
is installed, as well as for openings in roofs, floors and stairwells.
The current practice is to merely construct a makeshift guard rail from
lumber (such as lumber of a nominal 2"x4" inch (aprox. 50mm x 100mm) cross-
section, commonly referred to as a "two-by-four" or "2x4"). These types of
guard
rails, also referred to as fences or railings, are usually not as strong as
one
2o would like, and a worker falling against such railings can easily dislodge
the
makeshift railing causing the worker to fall and risk injury or death. The
dislodged makeshift railing may also fall down, creating a falling object
hazard for
lower levels of the construction site. These problems are of such a nature
that
the Occupational Safety and Health Administration, or OSHA, in the United
2s States of America and the Occupational Health and Safety Code, or OHS code,
in Canada have become alarmed. The regulations have been revised to require
temporary railings on all open elevated work surfaces or building structures
to
- 1-
CA 02505050 2005-04-22
withstand at least 890 Newtons (N) (aprox. 200 pounds) force applied in any
direction along the top rail without failure. To date there is no single
apparatus of
which we are aware that has the versitility to meet the requirements of these
regulations for all of the various work areas of a typical building under
s construction.
There are currently several examples of specific-use products available to
provide a safe work environment for an individual trade. In a first example
(i.e.
"example 1 "), there are guard rail systems available for a roof trades-
persons to
use while installing roofing products on a roof, such as a guard rail support
io shown in Canadian patent application 2,162,526. In a second example
(example 2), there are guard rail products for use only around openings or
edges
of flat (i.e. horizontal) surfaces. In a third example (example 3), there is
the
common practice of using a 2x4 wooden upright post nailed into an uppermost
exterior vertical wall and joined to a horizontal 2x4 to create a makeshift
railing
is that affords protection to the level above the erected walls. This allows
the
carpenters to proceed to the next level and begin installation of the floor on
top
of the walls.
However, there are disadvantages to these prior art products. Some
disadvantages of the products of example 1 are that they tend to be heavy
units
2o making it very hard for the carpenter to carry the units over the open
framing
members of a roof and to install the guard rail system. Further, the design of
the
support in Canadian patent application 2,162,526 limits the choice of
horizontal
rail members for installation as railings. For instance, where the tubular
guard
rail attachment elements (38) are sized for 2x4 lumber, larger 2x6 lumber
could
as not be used for a sloped surface setting to create a more secure guard rail
system. Yet a further disadvantage is that these horizontal rail members, when
installed in a fence formed by a series of three or more uprights, are
installed
-2-
CA 02505050 2005-04-22
butt-end-to-butt-end inside the retaining tubes (of the guard rail attachment
elements). Such confirguration makes removal of one horizontal rail anywhere
along the length of the rail system difficult without forcing the adjacent
horizontal
rail out of the tube, causing another area of the roof to be without fall
protection.
s A disadvantage of the products of example 2 is that the current practice is
to generally use complex and expensive metal systems or a series of brackets
in
combination with 2x4 lumber fastened together by nailing or screwing the
horizontal members to the vertical members. In most cases such assembly is
expensive due to material (lumber and fasteners) and labor costs.
io A disadvantage of the systems of example 3 is the excessive time
required to install and remove all of the uprights from their proper position
and to
construct a railing made entirely out of 2x4 lumber. This is also very costly
because the 2x4 lumber is seldom reusable upon disassembly of the railing.
Once this type of railing has been installed it is typically not as secure as
one
is would like, and it can create a falling object hazard to the workers below
as
noted earlier.
What is therefore desired is a novel variable rail safety system, which
overcomes the limitations and disadvantages of the existing systems and
products. Preferably, it should create a safe work environment for all trades
ao involved from start to finish of most or all aspects of a building during
construction. In particular, the novel system should keep manpower and
materials from sliding off or over the edge of the work surface of a building
during construction. The system should be mountable on various sloped roofs
as well as on vertical surfaces (walls), on level, or generally horizontal,
surfaces,
2s and around openings, such as floor openings and the like.
-3-
CA 02505050 2005-04-22
SUMMARY OF THE PRESENT INVENTION
According to the present invention, there is provided in one aspect a
guard rail support for removably receiving rail members to form a guard rail
safety system for removably attaching to a structure comprising:
s an elongate upright member having spaced first and second upright
attachment means, and mounting means for supporting said rail members;
an elongate base member adapted to be removably secured to said
structure and having spaced first and second base attachment means, said first
base attachment means adapted to be pivotally engaged with said first upright
io attachment means; and,
an elongate brace member having spaced first and second brace
attachment means, said first brace attachment means adaped to be pivotally
engaged with said second base attachment means, and said second brace
attacment means adapted to be selectively secured to said second upright
is attachment means to provide said upright member with a desired positioning
relative to said base member ranging between an acute angle and an obtuse
angle where said upright and base members are substantially linearly aligned.
The upright member also has openings that hold rails, such as various
sizes of lumber, in a vertically stacked array without the need to cut or
fasten the
ao lumber, and which allows for replacement of rails without significant
disturbance,
nor disassembly, of the rest of the system. Hence, there is provided in a
second
aspect a guard rail support for removably receiving rail members to form a
guard
rail safety system for removably attaching to a structure comprising:
an elongate upright member having spaced first and second upright
2s attachment means, and mounting means for supporting said rail members;
an elongate base member having spaced first and second base
attachment means, said first base attachment means adapted to be pivotally
-4-
CA 02505050 2005-04-22
engaged with said first upright attachment means, and including a resilient
tongue protruding from one end of said base member adapted to receive
fasteners to operatively secure said base member to said structure and to
allow
said base member to be raised from said structure pivotally about said secured
s tongue; and,
an elongate brace member having spaced first and second brace
attachment means, said first brace attachment means adaped to be pivotally
engaged with said second base attachment means, and said second brace
attacment means adapted to be selectively secured to said second upright
1o attachment means to provide said upright member with a desired positioning
relative to said base member.
The base also has a tongue particularly suited for roof work, namely the
tongue is used to mount the rail support to the roof, yet allows the base to
be
lifted for placing shingles thereunder. Hence, there is provided in a third
aspect
is a guard rail system removably installable to a structure comprising:
a plurality of rail members;
at least two rail supports for said rail members, each of said rail supports
comprising:
an elongate upright member having spaced first and second upright
2o attachment means, and mounting means for supporting said rail members
comprising at least one elongate opening in said upright member for receiving
at
least two of said rail members in a vertically stacked array and adapted to
allow
replacement of any one of said rail members without disassembly of the rest of
the system;
zs an elongate base member adapted to be removably secured to said
structure and having spaced first and second base attachment means, said first
-s-
CA 02505050 2005-04-22
base attachment means adapted to be pivotally engaged with said first upright
attachment means; and,
an elongate brace member having spaced first and second brace
attachment means, said first brace attachment means adaped to be pivotally
s engaged with said second base attachment means, and said second brace
attacment means adapted to be selectively secured to said second upright
attachment means to provide said upright member with a desired positioning
relative to said base member.
io BRIEF DESCRIPTION OF THE DRAWING FIGURES
Embodiments of the invention will now be described, by way of example
only, with reference to the accompanying drawings, wherein:
Figure 1 is a perspective view of a guard rail fence formed by a variable
rail safety system according to a preferred embodiment of the present
invention
is mounted on an inclined roof of a building under construction adjacent a
lower
edge of the roof;
Figure 1 a is a close-up view of an end of the fence in the circled portion of
fig.1 indicated by the letter "A" showing an erect support in an elevated
orientation and rails mounted thereto;
zo Figure 1 b is a close-up view of another part of the fence in the circled
portion of fig.1 indicated by the letter "B" showing an intermediate rail
support
having rails mounted thereto from both sides;
Figure 2a is an elevated side view of the rail support in an elevated
orientation;
2s Figure 2b is an end view of the rail support from the right side of fig.2a;
Figure 2c is an isometric view of the rail support of fig.2a;
Figure 2d is a plan view from above of the rail support of fig.2a;
Figure 3 is a exploded view of the various components of the rail support;
-6-
CA 02505050 2005-04-22
Figure 4 is an isometric view of the upright member of the rail support
showing the various components thereof;
Figure 5a is an isolated side view of the lower arm of the rail support;
Figure 5b is a plan view of the base member from the top of fig.5a
s showing various fastener apertures;
Figure 5c is a view similar to fig.5b but showing the base member in an
unfolded position as would be encountered during the manufacturing process;
Figure 5d is an end view of the u-shaped base member of fig.5a;
Figure 5e is an isometric view of the base member of fig.5a;
io Figure 6a is an isolated side view of the brace of the rail support showing
various fastener apertures therethrough;
Figure 6b is a plan view of the brace from the top of fig.6a;
Figure 6c is an end view of the brace of fig.6a;
Figure 6d is an isometric view of the brace of fig.6a;
15 Figure 7 is a side view of the rail support similar to that of fig.2a, but
showing: a) the rail support in solid line in an elevated orientation where
the
upright member is pivotally mounted to the base member and is held in such
orientation by the brace; b) the rail support in another elevated orientation
where the upright member (in dotted outline) is in a fully upright, or
vertical,
2o position perpendicular to the base member; and c) the rail support in a
flat
orientation where the upright member (in dotted outline) is brought clockwise
to a
horizontal position colinear to the base member, and held in such orientation
by
the brace and respective fasteners;
Figure 8 shows yet another use of the variable rail safety system of the
2s present invention, namely in an elevated orientation mounted onto a
generally
horizontal floor about the edges of an opening therein, such as for a future
stairwell or elevator shaft;
CA 02505050 2005-04-22
Figure 9 is an exploded view of the fasteners for use with the brace to
hold the rail support in the flat orientation;
Figure 10 shows another use of the variable rail safety system of the
present invention, namely mounted to and extending above the upper end of a
s wall being erected on a building under construction;
Figure 10a is a close-up view of the rail support in the circled portion of
fig.10 indicated by the letter "A" showing the rail support in a flat
orientation and
rails mounted thereto;
Figure 11 is a view similar to fig.1 showing the method of using the rail
io supports of the variable rail safety system on an inclined roof during
shingle
installation.
_8_
CA 02505050 2005-04-22
DESCRIPTION OF PREFERRED EMBODIMENTS
The figures show a guard rail system and assembly according to the
present invention, which is also referred to herein as a variable rail safety
system, or simply the "VRS system". Refering first to figs.1 to 1 b, the VRS
s system is defined by a guard rail fence (generally designated by the
reference
numeral 20) which is capable of being removably attached to various
structures,
most commonly to a building 22 under construction, to provide a safe working
area. One such structure for illustrative purposes is an inclined or pitched
roof
24 having a timber truss sub-structure (not shown) covered by plywood or like
to sheeting 26. The VRS system should be installed wherever a fall barrier is
required, such as along the front and/or side edges 28a, 28b of the roof.
Other
structures will be shown and discussed later.
Refering still to the embodiment shown in figs. 1-1b, the guard rail fence
20 is formed by removably attaching several elongate rail supports 40 to the
roof
is at spaced intervals along the edge 28a, and by mounting elongate rails or
rail
members 30 to the rail supports in a vertically spaced relationship. The rail
supports 40 may be adjusted to provide a substantially vertically oriented
guard
rail fence for most standard roof pitches, and for horizontal and vertical
structures as explained later. These rail supports may also be referred to as
zo posts or stanchions. The rails 30 in this embodiment are lenghts of typical
2x6
inch lumber, although they may be advantageously formed of other suitable
materials (such as recycled plastic) and be of various cross-secional shapes,
construction (e.g. solid, hollow, honeycomb or the like) and dimensions, as
will
be better appreciated later.
2s Refering now also to figs 2a-2d and 3, each rail support 40 has three
principal components, namely a first elongate upper member 50, a second
elongate "base" member 70 and a third elongate "brace" member 90. Although
_g_
CA 02505050 2005-04-22
the upper member 50 need not be oriented vertically when the rail support is
installed, it is desireable to do so for most applications, and so for ease of
reference the upper member will also be refered to herein as an upright
member,
or simply as an "upright".
s The upright 50 (seen in further detail in fig. 4 as well) has an outer
peripheral portion 52, formed by bending a length of flat metal bar, to define
a
first upright end 54, an opposed rounded second upright end 56, and an
intermediate body portion 55. Flat metal inserts 58 are welded to the inside
face
of the outer portion 52 at intervals along the intermediate body portion to
form
to longitudinally aligned first upper, second intermediate and third lower
openings
60a, 60b and 60c, respectively, which define mounting means for receiving and
supporting the rails 30. A first set of aligned holes 62 formed in the opposed
inserts 58 at the first upright end 54 define a first upright attachment
means, and
a second set of aligned holes 64 formed in the opposed inserts 58 at the
is opposed end of the lower opening 60c define a second upright attachment
means, the purpose of which will be discussed below. In the preferred
embodiment each elongate opening 60a, 60b, 60c is dimensioned to accept at
least two of the 2x6 rail members one atop another, namely in a vertically
stacked array. It will be appreciated that the upright may be constructed
longer
20 or shorter for particular applications, and thus require a different number
of
openings. It may also be possible to combine two or three of the openings to
form one longer opening capable of accepting more than two stacked rails, or
alternately to create a greater number of smaller openings, each capable of
holding only one rail, although this may not be preferred for reasons of
structural
2s stability andlor increase manufacturing costs.
The base member 70 (seen in further detail in figs. 5a-5e as well) has a
U-shaped body with upstanding sidewalk 76 joined by a floor portion 78, a
first
- 10-
CA 02505050 2005-04-22
base end 72, an opposed second base end 74 and an intermediate body portion
73. A first set of aligned holes 80 formed in the sidewalls 76 near the first
base
end 72 define a first base attachment means, and a second set of aligned holes
82 formed in the sidewalls 76 about midway along the intermediate body portion
s 73 define a second base attachment means. The first base atachment means
is pivotally engaged with the first upright attachment means by aligning the
respective first holes 62, 80 and passing a pin 42b (shown in fig.9) or like
means
therethrough to form a hinge point. A planar tongue 84 is formed at the second
base end 74 by extending the floor portion 78 away from the sidewalls 76. The
so tongue has means to facilitate securing of the base member 70 to the roof
24 in
the form of at least one, but preferably two or more holes 86a, 86b for
receiving
suitable fasteners (not shown) which operatively (but removably) secure the
base
member to the roof. However, the tongue, or at least that portion of the
tongue
between the last hole 86b and the upstanding sidewalls 76, should be suitably
1s resilient to provide a means of allowing the rest of the base member to be
lifted
from the structure (pivotally about the tongue) while the tongue remains
secured
to the structure. This feature is advantageous when laying shingles on a
pitched
roof. However, if further securing of the base member to the structure is
desired,
the intermediate body portion 73 has several holes 88 spaced along the floor
2o portion 78 for receiving suitable fasteners. It has been found that
extending the
holes 88 from the the second base end 74 past the second base attachment
means 82 and toward the first base end 72 provides for a more secure
attachment of the base member to vertical walls, as noted later.
The brace 90 (seen in further detail in figs. 6a-6d) is a tubular member of
2s rectangular cross-section having a first brace end 92, an opposed second
brace
end 94, and an intermediate body portion 93. A first set of aligned brace
holes
96 near the first brace end 92 define a first brace attachment means, and a
-11-
CA 02505050 2005-04-22
second set of aligned brace holes 98a-98h and 98i formed along the
intermediate body portion 93 and toward the second brace end 94, respectively,
define a second brace attachment means (collectively idendified as 98). The
first brace attachment means 96 is pivotally engaged with the second base
s attachment means 82 by aligning the respective first and second holes 96, 82
and passing a pin 42a (shown in fig.9) or like means therethrough. Further,
the
second brace attachment means 98 is selectively secured, as with a removable
pin, to the second upright attachment means 64 to provide the urpight with a
desired positioning relative to the base 70, namely in a range from an acute
1o angle (i.e. less than 90 degrees as shown by A in fig.7) to an obtuse angle
(i.e.
up to and including 180 degrees as shown by 02), and including a right angle
01. Hence, with the angle 01 the upright and base members are perpendicular
to one another, whereas with the angle 02 the upright and base members are
substantially linearly aligned, but pointing in opposed directions.
is Referring again to figs.? and 1, the rail support 40 forms a triangulated
frame capable of numerous orientations suitable for use on inclined
structures,
such as a roof. The roof slope is described as a pitch, which is a ratio of
the rise
(vertical V) to a given run (horizontal H - see fig.1 ). A ptich of 0/12 (also
0:12 or
0 in 12) means a roof is flat, and a pitch of 4/12 means a rise of 4 units
(inches,
2o feet, cm, m, etc) for a run of 12 units. A typical roof will have a pitch
between
0/12 to 10/12. The preferred embodiment of the rail support is adapted for use
in this range of pitches. Each of the brace holes 98a to 98h along the brace
90
allow the upright 50 to be positioned generally vertically when the base is
secured to a roof having such pitches. A chosen brace hole must be pinned to
Zs the second upright hole 64 to accommodate a desired pitch. The brace holes
98a to 98g are spaced along the brace to position the upright at an acute
angle
A (as indicated in solid outline by 50A in fig.7) to accommodate pitches of
10/12,
- 12-
CA 02505050 2005-04-22
9/12, 8/12, 7/12, 6/12, 5/12 and 4/12, respectively. The brace hole 98h is
located to place the upright at a right angle 01, perpendicular to the base 70
(as
indicated in dotted outline by 50B in fig.7), to accommodate a pitch of 0/12.
The
latter is suitable for use on a flat roof, or on other level structures, such
as by an
s opening 112 in a floor 110 (fig.8). It will be understood that the brace
need not
have all of the mentioned brace holes 98a-98h, and yet provide an adequate
range of desired pitches. As few as one hole may be adequate for a particular
use or user. Likewise, more or different holes may be provided for further
pitches. However, it has been found that the brace holes of the preferred
1o embodiment provide an optimum mix of versitility and manufacturing cost.
Another desireable feature is the earlier noted ability of the upright to be
brought beyond the perpendicular position into linear alignment with the base
70,
as indicated in dotted outline 50C in fig.7. This "flat" positioning of the
base and
upright members creates a long, rigid stanchion 40 (fig 9) particularly
suitable for
is use on vertical structures, such as creating a guard rail fence 20 (fig 11
) along
the top edge of a wall 114 (shown in fig.10 being raised toward a vertical
position
atop a floor 116 of a building 22 under construction). Figure 9 shows the flat
position in greater detail, and shows the pins 42a-42c and corresponding wing
nuts 44a-44c preferably used to secure the rail support in its various
positions.
2o In the instant case, the pin and nut 42a, 44a should be loosened but remain
engaged with the base 70 and brace 90, namely with the base holes 82 and
brace holes 96, to allow the brace to be brought into linear alignment with
the
base. However, the pins 42b, 42c and nuts 44b, 44c should be disengaged to
avoid interfering with the linear alignment of the upright 50 with the base
and
2s brace, as shown. When the members are linearly aligned, the distal brace
hole
98i should align with the second upright hole 64 for engagement by the pin and
nut 42c, 44c, and one of the second set of brace holes 98a-98h should also
align
-13-
CA 02505050 2005-04-22
with the second base holes 80 and the first upright holes 62 for engagement by
the pin and nut 42b, 44b. This latter pin engagement advatageously locks the
three members in the desired linearly aligned position, and makes the rail
support ready for mounting to the desired wall or like structure.
s With continued reference to figs 10, 10a, the above flat stanchion 40 is
secured to the wall 114 by means of several suitable fasteners (e.g. nails or
screws) placed through the base holes 88 (fig.5b) into a wall stud. Most of
the
upright 50 should protrude above the edge of the wall to provide a guard rail
fence of suitable height. In fig.10 two spaced stanchions are adequate for the
to relatively short wall, and more can be used for longer walls. In this case
the
spacing is suitable to receive two rails (preferably 2x4 or 2x6 standard
lenghts of
lumber), one in each set of the upright openings 60a and 60b. The fence 20
should be assembled and secured to the wall prior to its errection, while the
wall
lays flat on the floor 116. Once the wall is errected, the guard rail fence 20
is creates an effective safety barrier along the top edge of the wall,
particularly
when the next level of floor is being installed along that top edge.
Regarding installation of the present invention on a pitched roof that is
being shingled, and with reference to figure 11 (which shows multiple rows of
shingles 120), the VRS system is used by merely installing two screws or other
ao fasteners 87 through the holes 86a, 86b of the tongue 84 of each rail
support
into the top cord of the roof truss (not shown), thus sandwiching the roof's
plywood sheeting 26 therebetween. The upright is then brouhgt to a generally
vertical position, and, depending on the roof's pitch, one of the brace holes
98a-
98i is engaged with a pin 42c (fig 9) to the second upright hole 64 to
maintain the
z5 desired positioning. The rails are then placed through the upright openings
to
form the fence 20. As the rest of the base 70 is not fastened to the roof, the
lower end of the base may be conveniently raised slightly by roof trades-
persons
- 14-
CA 02505050 2005-04-22
to allow for the instalation of roofing products (i.e. the shingles 120) under
the
stanchion base 70, thereby allowing the trades-persons to advatageously
perform their complete installation without removal of the guard rail system,
and
thus maintain a safe work area. After the roofing work is completed, the VRS
s system is easily removed by first removing the rails 30 from the uprights,
and
then by merely lifting those shingles (indicated by 122) which cover the
respective tongues 84 of each stanchion, and removing the two fasteners 87
therefrom, to allow the stanchion to be lifted from the roof. These rail
supports
and rails are therefore advantageously available for re-use on another
building.
to To lengthen the VRS system shown in fig. 11 for longer roof lines, one
simply adds more supports 40 at spaced intervals and more rails 30 to form the
guard rail fence shown in figs. 1-1 b. It is preferred that the spacing
between the
supports be no more than about 10 feet (about 3 m) to accept a standard 12
foot
(about 3.6 m) length of 2x6 lumber and allow some overhang 32 beyond each
is upright opening, whether at the end of the fence (as in fig.1 a) or at an
intermediate support (as in fig. 1 b). Hence, the pairs of stacked rails 30 in
each
upright opening of an intermediate support (fig.1 b) form the earlier
mentioned
vertically stacked array of rails. A distinct advantage of this arrangement is
that it
allows any damaged rails to be replaced by merely sliding a selected rail out
of
ao its respective upright openings, without disturbing or requiring
disassembly of the
rest of the fence. The rails also remain lodged in the supports without
additional
fasteners or the like.
Other uses of the VRS system should now be apparent. This system may
be attached to the upper portion of a parapet wall on a roof to create an
upright
2s guard rail for a flat top roof perimeter. Because of the variable
inclinations
provided by the present rail support, it may also be used on bridge and road
construction where surfaces are not always level, as well as other industrial
and
- 15-
CA 02505050 2005-04-22
commercial applications. This system can be used to create a horizontal,
elevated guard rail fence around the edge of a work area to creating a safe
work
place. Referring to fig.8 again for example, the 90 degree, or upright,
orientation
allows for installation of fasteners through two or more of the base holes 88
s (fig.5b) (including the tongue holes 86a, 86b, if desired) into floors 110
or any
other flat, level surfaces, thus creating a upright guard rail fence for the
perimeter
of a work area or a floor opening 112 (such as an elevator shaft, stairwell,
mechanical shaft, etc.). Note that the base members 70 in fig.8 extend away
from the opening 112 so as to place the uprights 50 adjacent the opening.
1o However, the opposite orientation (i.e. base members facing toward the
opening)
may also be used to avoid workers stepping on the base members.
The VRS system may be manufactured out of any number of different
metals or materials. An alternative material to using metal is hardened
plastic as
well as structural rubber compounds. A wood product could be an alternative
1s material but may not contain the resilience factors needed over a long
period of
time.
The operation and many advantages of the present invention over the
prior art, including that of examples 1 to 3 in the background, may now be
better
understood.
zo The VRS system providies a rail support of reduced weight, but which still
provides the desired structural integrity. The rail support 40 is a light
weight unit
which should be capable of withstanding 890 Newton's of force applied in any
direction along the top rail of the guard rail fence 20. The present system is
further adapted to optionally use 2x6, 2x4 or other lumber as rails, and
allows for
2s these rails to pass atop one another through openings (60a-60c) in the
upright in
a staggered configuration, thus making it possible to remove one section of
the
guard rail (to load materials onto a roof, for instance) without jeopardizing
the
16-
CA 02505050 2005-04-22
integrity of the adjacent rails or work area. It is preferable to use 2x6
lumber as
rails on a sloped surface such as a roof, rather than the current practice of
using
2x4 lumber, due to the added safety factor.
The VRS system provided greater ease of installation. It is removably
s secured to a structure by using as few as 2 fasteners through the base
member
70, and then by merely sliding the multiple lumber rails 30 into the openings
of
respective uprights. Since no lumber needs to be cut or fastened together, the
rail supports and lumber are all reusable, thus saving cost for lumber,
fasteners
and labor. It therefore installs very quickly, and the use of so few fasteners
in the
so base leaves minimal surface degradation to the underlying structure.
By using a manufactured rail support the present invention minimizes
installation and removal time, and material cost, as compared to prior lumber
fences constructed from scratch. A further advantage of using the present
invention is that it provides a more secure guard rail, when using the same
15 length of fastener, such as a standard 3.5 inch (aprox. 88 mm) nail. To
illustrate,
the common practice of nailing 2x4 vertical posts to a wall (to act as rail
supports) results in only 2 inches (aprox. 50 mm) of nail penetration into the
wall.
In contrast, the holes in the thin base of the present rail support allow up
to 3.25
inches (aprox. 81 mm) of nail penetration into the wall. This also reduces the
2o previosly mentioned falling object hazard to workers below.
A further advantage over the prior art is that the manufactured rail support
of this invention may be installed in all of the configurations contemplated
by the
earlier prior art examples. Whereas the prior art provides single use devices,
the
present rail support has multiple applications, such as on flat roofs, pitched
roofs,
2s on walls and floors of various inclinations, around openings and the like.
The
VRS system can be installed at the top of exterior walls prior to the erection
of
the exterior walls, thereby creating a safety guard rail for the next level of
-17-
CA 02505050 2005-04-22
building. The present invention thus eliminates the need for purchasing a
separate apparatus for every individual type of application cited by the
earlier
examples.
The above description is intended in an illustrative rather than a restrictive
s sense, and variations to the specific configurations described may be
apparent
to skilled persons in adapting the present invention to other specific
applications.
Such variations are intended to form part of the present invention insofar as
they
are within the spirit and scope of the claims below. For instance, the second
upright hole 64 could be placed higher in the next set of inserts 50, but this
would
to require a longer (and thus heavier and more costly) brace to provide the
same
range of motion for the upright about the base. Likewise, the openings in the
uprights may be substituted by other mounting means for the rails, such as
channel members fixed to the uprights, but this would needlessly add weight
and
cost due to more material and manufacturing requirements.
-18-
