Note: Descriptions are shown in the official language in which they were submitted.
CA 02306581 2000-04-25
-1-
BACKGROUND OF THE INVENTION
i) Field of the Invention
This invention relates to a clamp for securing wood planks in
side-by-side relationship, to a scaffold assembly and to a method of forming a
platform assembly.
ii) Description of Prior Art
Scaffold structures are employed to support working platforms
for construction workers during the repair and construction of buildings. The
platforms are formed by positioning wood planks in side-by-side relationship
across horizontal support members of the scaffold structure. Several different
working platforms may be supported by the scaffold structure, at the same or
different elevations to provide access to different work sites on the building
under construction or repair.
The wood planks are typically 12 or 14 feet in length, 2 inches
thick and 8, 10 or 12 inches wide. After positioning the planks in side-by-
side
relationship on the scaffolding structure, it is generally preferred to secure
them
together to provide stability in the platform assembly and for greater
security
for the construction worker.
A common practice in providing such stability and security is to
affix a wooden cleat transversely of the adjacent planks; typically the wooden
cleat is affixed by nailing it to the planks. If the wooden cleat is affixed
to the
planks across their upper surfaces, which are the more accessible surfaces, it
presents a hazard to a construction worker on the platform assembly, since it
forms a trip or obstacle interrupting the otherwise generally flat upper
platform
surface. Consequently, it is preferred to affix the cleat across the under
surfaces of the positioned planks; however, the under surfaces are less
accessible, necessitate the existence of a lower working platform or site, and
also require that the nailing be in an upward direction which necessitates a
~
CA 02306581 2000-04-25
-2-
sufficient load on the platform to hold the planks in position during the
nailing
operation. This may mean that a second construction worker stands or sits on
the unsecured platform planks while a first construction worker carries out
the
nailing operation below the positioned planks.
It is impractical to carry out the nailing operation, in forming the
platform assembly, at ground level, since the resulting platform assembly is
then too heavy to lift and position on the scaffolding structure.
When the construction or repair is complete and the scaffold
structure is disassembled it is necessary to remove the nails affixing the
wooden cleat to the planks, before the planks can be lowered to ground level.
The nailing and nail removing operations are time consuming and
various proposals have been made for mechanical clamps to replace the nailing.
These mechanical clamps, however, are typically of fairly complex structure
and components of the clamp form an obstacle or trip on the upper platform
surface, creating a hazard. These clamps have not enjoyed commercial
acceptance.
Typical prior proposals for clamps for platform assemblies are
shown in US Patents 2,569,450 - Bouton; 2,928,443 - Sevachko; 4,187,929 -
Cyr and 4,534,448 - Turner. Each of these prior clamps has a clamp
component which extends across the upper surfaces of the plank assembly,
thereby creating a tripping hazard, as well as a clamp component across the
under surfaces of the plank assembly.
SUMMARY OF THE INVENTION
This invention seeks to provide a clamp for scaffolding planks of
simple structure which can be readily applied to and removed from a platform
assembly supported by a scaffolding structure.
Still further this invention seeks to provide a clamp for
scaffolding planks which holds the planks securely in side-by-side
relationship
CA 02306581 2000-04-25
-3-
with the outermost faces, especially the upper faces, of the planks
unobstructed
by the component parts of the clamp; in the case where the upper surfaces are
unobstructed, an uninterrupted platform surface is thereby formed from the
upper faces of the planks.
Still further the invention seeks to provide a scaffold assembly
employing a clamp or clamps to secure a platform assembly or assemblies
supported by a scaffolding structure, such that the upper surface of the
platform
assembly or assemblies may be uninterrupted by the clamp or clamps.
This invention also seeks to provide a method of forming a
platform assembly supported on a scaffolding structure in which the planks of
the platform assembly are securely held in side-by-side relationship with a
clamp such that an uninterrupted platform upper surface may be formed.
In accordance with one aspect of the invention there is provided a
clamp for securing together a plurality of wood planks in side-by-side
relationship to form a platform comprising: a clamp body having a recess
defined therein adapted to receive a plurality of wood planks to form an
assembly of the planks in side-by-side relationship with the upper faces of
the
planks disposed such that an uninterrupted platform upper surface is formed by
the upper faces; and first and second plank engaging means extending inwardly
of said body into said recess, and adapted to securely engage outer side walls
of
the assembly.
In accordance with another aspect of the invention there is
provided a scaffold assembly comprising: a scaffolding structure and at least
one platform assembly supported on said scaffolding structure, said platform
assembly comprising a plurality of wood planks in side-by-side relationship,
and secured in said relationship by at least one clamp, said planks being
received in a recess of said clamp, said clamp securely engaging opposed outer
side walls of said plurality of wood planks with the upper faces of said
planks
~
CA 02306581 2000-04-25
-4-
disposed such that an uninterrupted platform upper surface is formed by the
upper faces of the planks engaged by the clamp.
In accordance with yet another aspect of the invention there is
provided in a method of forming a platform assembly supported on a
scaffolding structure to provide a working platform in which wood planks are
positioned in side-by-side relationship and secured together as a platform
assembly by a clamp, the improvement wherein the planks of the platform
assembly are received in a recess of said clamp and said clamp securely
engages opposed side walls of the platform assembly with the upper faces of
the planks disposed such that an uninterrupted platform upper surface is
formed
by the upper faces of the planks engaged by the clamp.
In still another aspect of the invention there is provided a clamp
for securing together a plurality of wood planks in side-by-side relationship
to
form a platform comprising: a clamp body having a recess defined therein
adapted to receive a plurality of wood planks to form an assembly of the
planks
in side-by-side relationship, such that a platform is formed by said planks;
and
first and second plank engaging means extending inwardly of said body into
said recess, said first and second engaging means each comprising wood
penetrating members adapted to penetrate the outer side walls of the assembly.
DESCRIPTION OF PREFERRED EMBODIMENTS
In a specific embodiment of the invention, a clamp for securing
together a plurality of wood planks in side-by-side relationship to form a
platform comprises an elongate bar having opposed first and second end
flanges extending from opposed first and second ends of the bar.
A recess is defined between the end flanges and the bar, the
recess being adapted to receive a plurality of wood planks to form the
assembly
of planks in side-by-side relationship with the upper faces of the planks
~
CA 02306581 2000-04-25
-S-
disposed such that an uninterrupted platform upper surface is formed by the
upper faces of the planks.
First and second plank engaging means extending inwardly of the
first and second flanges, respectively, into the recess for securely engaging
outer side walls of the assembly of wood planks.
The clamp of the invention preferably has opposed wood
penetrating members which penetrate the wood planks at opposed sides of the
assembly of wood planks in their side-by-side relationship. Suitably at least
one of the plank engaging means is moveable inwardly and outwardly of the
recess for penetrating engagement of the wood planks received in the recess of
the clamp, by the wood penetrating members.
In one embodiment the moveable plank engaging means
comprise a rotatable screw supporting an abutment member, for example, an
abutment plate, adjacent but spaced apart from a wood penetrating end of the
screw. This arrangement is somewhat similar to the screw j ack except that the
screw extends beyond the abutment plate to terminate in the wood penetrating
end.
A second plank engaging means may comprise one or more
stationary wood penetrating spikes extending inwardly from a flange of the
clamp.
A scaffold assembly of the invention may include a plurality of
the clamps in spaced apart relationship along the underside of the assembly of
planks in order to better secure the assembly. In general, it is preferable to
employ at least two spaced apart clamps, the clamps preferably being
positioned at opposed ends of the elongate assembly of planks, however, a
single clamp will also suffice for each assembly of planks forming a platform
assembly.
CA 02306581 2000-04-25
-6-
Furthermore, the scaffold assembly may include a plurality of
platform assemblies secured by means of the clamps of the invention. These
platform assemblies may be at the same and at different elevations of the
scaffolding structure to permit construction workers to work at different
working sites. Suitably the different platform assemblies may be positioned
relative to one another in the scaffolding structure, to permit a construction
worker to move easily from one platform assembly to another.
The clamp may secure two or more planks in side-by-side
relationship, however, in the simplest case the clamp secures two planks in
side-by-side relationship and for most purposes this forms a platform of
adequate width to provide a safe working platform.
Reference herein to an uninterrupted platform upper surface
means that a component part or parts of the clamp do not lie on or extend over
the upper faces of the planks such as would present an obstacle or potential
trip
1 S on the platform upper surface, to a construction worker located on the
platform.
In the most preferred embodiments of the invention the upper
faces of the planks are disposed above the recess such that an uninterrupted
platform upper surface is formed by the upper faces above the clamp.
In some less advantageous embodiments the end flanges and the
abutment plate might extend to a height above the elongate bar greater than
the
thickness of the wood planks. In such case the end flanges and abutment plate
may project above the side walls of the plank assembly, however, such
projection does not interfere with the platform upper surface which remains
uninterrupted.
Likewise where a handle is mounted on the outer end of the
rotatable screw for ease in rotating the screw for advancement into the recess
and withdrawal from the recess, the handle might extend to a height above the
upper faces of the planks, however it will be remote from the upper platform
~
CA 02306581 2000-04-25
_ ') _
surface and will not overlie or otherwise present an obstacle to a person
working on the platform.
In general, it is advantageous and preferable to mount the clamp
from the underside of the plank assembly such that the outermost faces of the
planks are the upper faces of the plank assembly, and are uninterrupted by the
clamp. In this way, an uninterrupted platform working surface is formed by the
plank assembly, free of obstacles from the clamp.
On the other hand, the clamp will function to secure the assembly
if mounted from the upper side of the plank assembly. In this case the
outermost faces of the planks are the lower faces and the clamp body lies
across the upper platform surface formed by the plank assembly.
The clamp may be brightly coloured and highly visible such that
it is unlikely to prevent a serious obstacle to a worker on the platform,
especially if it is located adjacent the scaffolding structure.
Some clamps may typically be employed to mount planks from
the upper side, when planks overlap as is the case when an extended platform
is
produced in the longitudinal direction of the planks. In this case the ends of
a
first plank assembly may overlie the ends of a second longitudinally adjacent
assembly, and it may be preferred to secure the ends of the underlying second
assembly on the upper side of their planks adjacent the overlying ends of the
first plank assembly.
BRIEF DESCRIPTION OF DRAWINGS
FIG.1 is a schematic, fragmentary perspective view of a
scaffold assembly of the invention in which platform assemblies are secured by
clamps of the invention;
FIG. 2 is a top plan of the clamp of the invention with a partial
view of an assembly of planks;
~
CA 02306581 2000-04-25
_ g _
FIG. 3 is a front elevation of the clamp of FIG. 2 with a partial
view of the assembly of planks;
FIG. 4 is a cross-section on line 4-4 of FIG. 3 with a partial
view of the planks; and
FIG. 5 is a schematic, front elevation of a scaffold assembly in
which three platform assemblies extend longitudinally and partly overlapping.
DESCRIPTION OF PREFERRED EMBODIMENTS
WITH REFERENCE TO THE DRAWINGS
With further reference to FIG. 1, a scaffold assembly 10
comprises a scaffolding structure 12 and platform assemblies including
platform assemblies 14 and 16.
Platform assembly 14 is secured by a clamp 18 and platform
assembly 16 is secured by a clamp 20.
The scaffolding structure 12 comprises vertical members 22,
1 S horizontal members 24, diagonal members 26 and bracing members 28 which
collaborate to form a firm structure, in conventional manner: The nature of
the
connections between the different members of the scaffolding structure is well
known and is not the subject of the invention.
The platform assemblies including the platform assemblies 14
and 16 are supported on horizontal members 24 of the scaffolding structure 12.
With further reference to FIGS. 2, 3 and 4, clamp 18 comprises
an elongate bar 30 and opposed end flanges 32 and 34. End flange 32 has a flat
inner face 36 and end flange 34 has a flat inner face 38, the faces 36 and 38
being generally parallel and in opposed relationship.
Elongate bar 30 has a flat upper wall 40 and faces 36 and 38
extend generally perpendicularly of wall 40.
A bore 42 extends through end flange 32 and is aligned with a
threaded bore 46 in a threaded nut 44 which is welded to end flange 32. A
CA 02306581 2000-04-25
-9-
screw 48 is threaded mounted in threaded bore 46 and extends through bore 42.
Screw 48 has a wood penetrating end 50 and a handle 52.
An abutment plate 54 is supported by support nut 56 on screw 48
such that abutment plate 54 is adjacent to but spaced from wood penetrating
end S0. The abutment plate 54 is of disk-shape as illustrated but may be of
any
polygonal shape including triangular, rectangular and pentagonal.
Support nut 56 is threadedly mounted on and welded to screw 48
so that it rotates with screw 48. Abutment plate 54 has an exposed abutment
face 58, and a face 60 opposed to abutment face 58 which face 60 is welded to
an opposed face 62 of support nut 56. Thus, abutment plate 54 and support nut
56 rotate with screw 48.
A pair of spikes 64 and 66 extend inwardly of end flange 34.
Spikes 64 and 66 are spaced apart and extend generally perpendicularly
inwardly of the flat inner face 38 of end flange 34.
Abutment face 58 lies in a plane which is generally perpendicular
to the flat upper wall 40 of elongate bar 30 and generally parallel to the
flat
inner faces 36 and 38 of end flanges 32 and 34, respectively.
As more particularly evident from FIG. 5, elongate bar 30 is
defined by a tube 68 of rectangular cross-section.
A recess or slot 70 is defined in clamp 18 between the flat inner
faces 36 and 38 of end flanges 32 and 34 respectively, and the flat upper wall
40 of elongate bar 30; and a variable slot 94 is defined within recess 70
between abutment face 58, flat inner face 38 of end flange 34, and flat upper
wall 40 of elongate bar 30.
With further reference, again, to FIG. 1 and also to FIGS. 2, 3
and 4, a platform assembly 14 comprises a pair of planks 72 and 74 in side-by-
side relationship, in which an inner side wall 76 of plank 72 contacts an
inner
CA 02306581 2000-04-25
- 10-
side wall 78 of plank 74, with the planks 72 and 74 received in recess 70 and
slot 94 of clamp 18.
The outer side wall 80 of plank 72 is penetrated by wood
penetrating end 50 of screw 48 with the abutment face 58 of abutment plate 54
abutting outer side wall 80. The spikes 64 and 66 penetrate outer side wall 82
of plank 74 and flat inner face 38 of end flap 34 abut the outer side wall 82.
It will be understood that the description hereinbefore of claim 18
applies equally to the other clamps employed in the assembly, including clamp
20. Likewise it will be understood that the description hereinbefore of
platform
assembly 14 applies equally to the other platform assemblies including
platform assembly 16.
The reference herein to the inner faces 36 and 38 being generally
perpendicular to flat upper wall 40, to the spikes 64 and 66 being generally
perpendicular to flat inner face 38 and to the abutment face 58 being
contained
in a plane generally perpendicular to flat upper wall 40, and any other
references herein to general perpendicularity, are to be understood as
extending
to structures in which parts or surfaces are truly perpendicular, or are, for
all
practical purposes, to be considered perpendicular, in that the deviation from
actual perpendicularity does not substantially defeat the structural
relationships
requiring that the planks 72 and 74 be securely contained in recess 70 and
slot
94.
With greater particularity, lower faces 84 and 86 of planks 72 and
74 respectively contact flat upper wall 40 of elongate bar 30, while the outer
side walls 80 and 82 respectively contact abutment face 58 and flat inner face
38, respectively, whereby the planks 72 and 74 mate with slot 94 within recess
70, which slot 94 is defined between abutment face 58 and flat inner face 38
and flat upper wall 40.
CA 02306581 2000-04-25
-11-
In accordance with the invention in its more preferred
embodiment, end flanges 32 and 34 extend a height above flat upper wall 40 of
elongate bar 30 which is less than the thickness of planks 72 and 74 such that
the upper faces 88 and 90 of planks 72 and 74, respectively, are disposed
above
recess 70. Likewise, abutment plate 54 and support nut 56 extend radially
outwardly of screw 48 such that at their maximum height above screw 48, they
are disposed below upper faces 88 and 90 of the planks 72 and 74,
respectively.
In this way, the upper faces 88 and 90 define an upper platform surface 92
which is uninterrupted by a part or component of the clamp 18, so that the
clamp 18 does not present an obstacle or trip on the upper platform surface
92.
In use, the scaffolding structure 12 is first assembled in
conventional manner as well known to persons in the art.
Individual planks such as 72 and 74 are then positioned across
horizontal members 24 of the scaffolding structure at an elevation at which a
platform assembly 14 is desired within the scaffolding structure 12. The
planks
72 and 74 are positioned in side-by-side relationship and a clamp 18 is
positioned below planks 72 and 74 with the lower faces 84 and 86 of the planks
72 and 74 contacting the flat upper wall 40 of the elongate bar 30 of clamp
18.
While holding the clamp 18 in this position, the screw 48 is
rotated by means of handle 52 to advance wood penetrating end 50 and
abutment plate 54 towards outer side walls 80 of plank 72, with the spikes 64
and 66 extending towards outer side wall 82 of plank 74. When the distance
separating wood penetrating end 50 of screw 48 and the outer ends of spikes 64
and 66 matches the width of the assembly 14 defined by the combined planks
72 and 74 in side-by-side relationship with inside walls 76 and 78 in contact,
further advancement of screw 48 results in penetration of outer side wall 80
by
wood penetrating end 50, and penetration of outer side wall 82 by spikes 64
and 66. Further rotation of screw 48 by handle 52 is continued until abutment
CA 02306581 2000-04-25
-12-
face 58 of abutment plate 54 abuts outer side wall 80 such that wood
penetrating end 50 penetrates plank 72 at its outer side wall 80 to its
maximum
extent, and preferably until the spikes 64 and 66, fully penetrate plank 76 at
outer side wall 82 and flat inner face 38 of end flange 34 abuts the outer
side
wall 82 of plank 74.
In this configuration the planks 72 and 74 are securely held in
side-by-side relationship in recess 70 and more especially within the
adjustable
slot 94 of recess 70. The upper faces 88 and 90 of the planks 72 and 74, as
indicated above, are disposed above end flanges 32 and 34 and above abutment
plate 54 and support nut 56 whereby the upper faces 88 and 90 form an upper
platform surface which is uninterrupted and unobstructed by any part of the
clamp 18.
The platform assembly 16 is constructed in similar manner with
clamp 20 and a pair of planks similar to planks 72 and 74.
In this way a plurality of platform assemblies including the
assemblies 14 and 16 can be formed within scaffolding structure 12 to provide
platforms for the construction workers at different work sites at the same and
different elevations of the scaffolding structure to provide access to
different
construction work sites.
When the scaffold assembly is to be disassembled at the
completion of the construction operation, the clamps are removed by rotating
screw 48 in the reverse direction by means of handle 52 whereby the distance
separating wood penetrating end 50 and outer ends of spikes 64 and 66 expands
or enlarges such that wood penetrating end 50 and spikes 64 and 66 are
withdrawn from penetration of the wood planks 72 and 74 respectively,
whereafter the clamp 18 and the individual planks 72 and 74 may be lowered to
ground level and may then be stored for future use or transported to a new
construction site.
CA 02306581 2000-04-25
-13-
The other platform assemblies including assembly 16 are
disassembled in the same manner whereafter the scaffolding structure 12 is
disassembled in conventional manner as will be understood by persons in the
art.
It will be seen that the invention provides a clamp exemplified by
clamp 18 of simple structure, which is readily employed to secure planks in
side-by-side relationship, and can readily be disassembled from the planks.
The mode of securement provided by the clamp of the invention avoids clamp
parts or components extending across the upper faces of the planks, and indeed
in the more preferred embodiments the components of the clamp are all, in use,
disposed remote from the upper faces of the planks and do not contact or
extend over the upper faces of the planks.
In the particular configuration of the handle 52 illustrated in FIG.
3, it can be envisaged that the handle 52 might extend to a height above the
upper faces 88 and 90 of the planks 72 and 74, but such handle 52 does not
extend across the upper faces 88 and 90 and indeed extends outwardly so that
it
does not, in any way, obstruct the platform surface 92.
With further reference to FIG. 5, a scaffold assembly 100
comprises a scaffolding structure 112 and platform assemblies 114, 115 and
116 extending longitudinally of the planks.
Platform assembly 115 has ends 117 and 119 which overlie the
ends 121 and 123 of plank assemblies 114 and 116, respectively.
Clamp 118 secures assembly 114 from the underside at one end
and clamp 120 secures assembly 116 from the underside at one end. Clamps
125, on the other hand, secure assemblies 114 and 116 from the upper side
adjacent ends 117 and 119 of assembly 11 S and thus above ends 121 and 123.
Clamps 127 secure the planks of assembly 115 from the
underside.
CA 02306581 2000-04-25
- 14-
Although clamps 125 extend above assemblies 114 and 116 they
are adjacent to and slightly below assembly 115 and thus do not present an
extra obstacle. Additionally clamps 125 on assemblies 114 and 116 act as
stops to limit longitudinal movement of assembly 115 relative to assemblies
114 and 116.
It will be recognized that variations in the structure described and
illustrated hereinbefore may be made without departing from the spirit of the
invention and without avoiding the spirit of the claims hereinafter.
