Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ADJUSTABLE AND TRANSPORTABLE SCAFFOLDING
TECHNICAL FIELD
The present invention relates to an adjustable and
transportable scaffolding and more particularly to an
adjustable leg support mechanism which provides ease of
leveling and transporting a scaffolding on an irregular
ground support surface.
BACKGROUND ART
Scaffolding devices comprising interconnectable
tubular frame members are well known in the art whereby to
support people and material in an elevated position whereby
to facilitate working on structures such as building
structures or working adjacent or under elevated ceilings.
When working on scaffolding outdoors, often the ground area
adjacent the structure is irregular and it is therefore
necessary before climbing such scaffolding or errecting such
scaffolding that the ground be preferably level or else the
vertical corner posts of the scaffolding are shimmed by
using all sorts of material whereby the base of the
scaffolding lies substantially in a planar horizontal plane.
A problem with such shimming is that often it becomes
disengaged and this can cause the scaffolding to collapse
resulting in injuries and sometimes death to personnel
working on such structures or in the vicinity of such
structure.
Another disadvantage of scaffolding is that once
erected they are difficult to transport to relocate at a
different site close by. Usually the entire scaffolding
structure is disassembled and re-assembled at the new site
where again it may be required to shim the corner vertical
post to re-level the structure prior to assembly thereof.
This is a time consuming process.
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Solutions have been proposed to remedy these
problems and reference is made to U.S. Patent 4,171,033
which proposes such a solution. One solution is to mount
the scaffolding on wheels which may be retracted, as
illustrated in U.S. Patent 5, 937, 967. In order to maintain
the working platform of the scaffolding substantially
horizontal at a desired position, telescopic legs have also
been proposed as described and shown in U.S. Patent
4,171,033. However, such proposed solution is very time-
consuming and is permanently adapted to a specific
scaffolding platform. There is therefore a need to also
provide a scaffolding which incorporates features of
adjustability and transportability and which is easy to
disassemble and assemble and which can be transported by
small transport vehicles such as a pick-up truck or the like
small vehicles. There is also a need to provide an
adjustable and transportable scaffolding which is safe to
use and which can be erected very quickly and easily
displaceable without disassembling the scaffolding.
U.S. Patent 5,588,500 discloses a scaffolding
wherein at the corner post of the scaffolding there is
provided outriggers that can be positioned so as to protrude
outside the corner post of the scaffolding to elevate the
entire scaffolding in order to stabilize it as a security
precaution. It is preferable to elevate it during use so
that it is not turned over or moved accidentally. When the
scaffolding is not used, these outriggers are folded and
accommodated in the side surfaces of the scaffolding. These
outriggers are not used to hold the scaffolding in a
horizontal plane when supported on an angulated surface nor
was it designed to do so. U.S. Patent 1,442,075 describes a
scaffolding hoist which is secured to two spaced-apart
upright posts. The hoist engages the post and a person or
two people standing on the scaffold operate the hoist so as
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to lift the support platform in a substantially horizontal
plane. This hoist has no relationship to the ground support
for the post but merely a means for elevating a platform on
two support posts. If each of the hoists was to be operated
independently then the support platform would be angulated
and become dangerous. Thus, with this patent the scaffold
hoist must be operated substantially in synchronism to
maintain the support platform substantially horizontal.
DISCLOSURE OF INVENTION
It is therefore a feature of the present invention
to provide an adjustable and transportable scaffolding which
substantially overcomes the disadvantages of the above-
mentioned prior art and which provides for the required
existing needs.
Another feature of the present invention is to
provide an adjustable leg support mechanism which is
securable to vertical corner posts of a scaffolding
structure and which is easy to connect thereto, and which is
quick and easy to adjust by a single person.
Another feature of the present invention is to
provide an adjustable leg support mechanism to which is
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connectable wheels whereby to transport and displace an
assembled scaffolding from different locations.
Another feature of the present invention is to
provide a scaffolding and wherein the wheels can be
displaced and locked about the scaffolding corner posts for
ease of displacing the scaffolding.
According to a still further feature of the
present invention there is provided a support foot for a
scaffolding which is slidingly displaced over a ground
support surface even when covered with snow.
According to the above features, from a broad
aspect, the present invention provides an adjustable leg
support mechanism for a scaffolding having vertical corner
frame members connected to horizontal frame members and
cross-braces. The mechanism is characterized in that it
comprises an open-ended sleeve adapted to receive a support
rod therethrough and wherein the support rod has at least a
longitudinal toothed edge section and a bottom support foot.
A tooth engaging member is pivotally secured to the sleeve
and has a tooth engaging head biased against the toothed
edge inside the sleeve for supporting the sleeve about the
support rod while permitting upward displacement of the
sleeve about the rod. Means is provided to unbias the tooth
engaging head from the toothed edge to permit downward
displacement of the sleeve about the rod. Arresting means
is provided to lock the tooth engaging head in arresting
position with the toothed edge. A rod connector is secured
to the sleeve for connection to a transverse tubular rod
interconnecting two opposed leg support mechanisms together.
A vertical connecting post is secured to the rod connector
for release engagement with a hollow tubular end of one of
the vertical corner frame members whereby said scaffolding
can be leveled at a bottom end thereof on an irregular
ground surface.
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BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will
now be described with reference to the accompanying drawings
in which:
FIGURE 1 is a simplified side view, partly
fragmented, showing a section of a scaffolding and to which
is secured an adjustable leg support mechanism to each of
two vertical corner posts of the scaffolding for ease of
level adjustment of the scaffolding on an irregular ground
surface;
FIGURE 2 is a side view, partly sectioned,
illustrating the construction of the open-ended sleeve and
some of its component parts for displaceable connection
about a support rod;
FIGURE 3 is a top view of the open-ended sleeve
substantially as illustrated in Figure 2;
FIGURE 4 is a side view illustrating the support
sleeve and its rod connector and attachment means to secure
to a vertical connecting post of a scaffolding structure;
FIGURE 5 is a side section view similar to
Figure 2 but showing the support rod having a serrated edge
and extending through the open-ended sleeve;
FIGURE 6 is a side view, partly sectioned, of
the sliding foot plate and its vertical connector to secure
to the bottom of a hollow corner frame member of a
scaffolding;
FIGURE 7A is a side view showing the support rod
secured to the foot plate;
FIGURE 7B is an end view of Figure 7A;
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FIGURE 8 is a partly sectioned side view of the
sleeve showing a support wheel secured thereto as well as an
adjustable rod connector secured to the sleeve;
FIGURE 9 is a top view illustrating the
5 construction of the arcuate horizontal lock flange;
FIGURE 10 is a side view of Figure 9 illustrating
the disposition of the lock flange relative to a pivot
connecting flange secured to the open-ended sleeve;
FIGURE 11 is a top view showing an adjustable leg
support mechanism with the attachments as shown in Figure 8
and secured to a telescopic horizontal rod;
FIGURE 12 is a side view showing the other side
of a tandem arrangement of two adjustable leg support
mechanisms with wheels secured together by the telescopic
rod;
FIGURE 13 is a top view illustrating the
construction of a carriage assembly secured to the
adjustable leg support mechanism of a tandem arrangement;
and
FIGURE 14 is a view similar to. Figure 13 but
showing the wheels interconnected to the adjustable leg
support mechanism at different angles with respect to the
corner post of a scaffolding whereby to displace the
scaffolding sideways or at an angle.
MODES FOR CARRYING OUT THE INVENTION
Referring now to the drawings and more
particularly to Figure 1, there is shown generally at 10,
typical scaffolding structure constructed of tubular frame
members. Only a bottom end section of a scaffolding
structure 10 is illustrated and it comprises of vertical
corner frame members or posts (usually tubular rods)11 and
11' connected to horizontal frame members 12 and to cross-
braces 13, as is well known in the art, whereby to construct
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a stable and rigid scaffolding assembly. Usually the bottom
section of a scaffolding assembly is assembled on a ground
surface 14 with the vertical corner frame members shimmed to
level the lower section. After being leveled, further
sections 15 are assembled on top of the bottom section and
planks are placed on top of the horizontal frame members.
The present invention provides for an adjustable
leg support mechanism 20 which is connectable to one or more
of the vertical corner frame members 11. The adjustable leg
support mechanism will now be described with further
reference to Figures 2 to 5.
The adjustable leg support mechanism 20 comprises
an open-ended sleeve 21 which is adapted to receive a
support rod 22 therethrough and wherein the support rod 22
has at least a longitudinal toothed edge section 23 and is
adapted to secure to a bottom support foot 24, as
illustrated in Figure 6. A tooth engaging member 25 is
pivotally secured to the sleeve 21 and has a tooth engaging
head 26 which is biased against the toothed edge 23 inside
the sleeve 22 for supporting the sleeve about the support
rod 22 at a desired location therealong. The tooth engaging
member is a ratchet-like member and permits upward
displacement of the sleeve 21 about the support rod 22 by
simply pulling the sleeve upwardly along the rod 22.
The tooth engaging head 26 is mounted on a pivot
pin 27 and is provided with a lever arm 28 integrally formed
therewith and which constitutes a means to unbias the tooth
engaging head from the toothed edge 23 to permit downward
displacement of the sleeve 21 about the rod 22. The lever
28, due to its own weight, biases the tooth engaging head
inwardly of a rectangular passage of the open-ended sleeve
through an aperture 30 formed in a side wall 31 of the
sleeve 21. It is pointed out that the support rod 22 is of
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square cross-section and received in close sliding fit
within the rectangular passage 29 of the sleeve.
As shown in Figure 5, the saw tooth formations 23'
each define a horizontal support ledge 32 and an outwardly
sloping wall section 33. The tooth engaging head 26 has an
engaging projection 34 which is of wedge-shaped formation
34' and defines a flat bottom wall 35 for seated engagement
on a support ledge 32 of the saw tooth formation and a
rearwardly sloping upper wall 36 for frictional sliding
engagement against the outwardly sloping wall section 33
when the sleeve is retracted upwardly along the support rod
and thereby providing the ratchet effect.
As better illustrated in Figures 2 and 3, the
tooth engaging head 26 is pivotally secured by the pivot pin
27 which is supported between a pair of support flanges 37
secured to the sleeve 21 and hereinshown as forming an
integral part thereof extending beyond the rectangular
passage 29. In order to disconnect the sleeve from the
support rod, it is merely necessary to pull the lever arm 28
upwardly in the direction of arrow 38,.as shown in Figure 2
thereby causing the wedge shape formation 34 to retract
outwardly of the rectangular passage 29 through the aperture
30.
With further reference to Figures 2 and 5, there
is illustrated an arresting means in the form of a locking
lever 40 which is hingedly connected to the sleeve support
flanges 37 by a pivot connection 41. The locking lever 40
has an arresting formation 42 for removable engagement with
the tooth engaging head 26 to prevent displacement of the
lever arm 28 and disengagement of the engaging projection 34
with the toothed edge section 23 of the support rod 22.
This locking lever 40 has a finger engaging formation 43 to
provide disconnection of the arresting formation 42 from a
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notch 44 provided in a rear top portion of the tooth
engaging head 26.
As shown in Figures 3 and 4, a rod connector 50 in
the form of a tubular member is secured to the sleeve 21 for
connection to a transverse tubular rod 51, as will be
described later in detail, whereby to interconnect two
opposed leg support mechanisms 20 together in tandem, as
illustrated in Figures 1, 13 and 14.
Attachment means in the form of a vertical
connecting post 52, is also secured to the sleeve 21 and
herein via the rod connector 50 on a top wall thereof and
projects upwardly on a vertical axis 52' which is parallel
to the longitudinal axis 53 of the sleeve. The connector 50
extends on a transverse longitudinal axis 54. The vertical
post 52 is structured for release engagement with a hollow
tubular end section 55, see Figure 6, of a vertical corner
frame member, herein a hollow tubular frame member 11 as is
illustrated in Figure 6.
The sleeve 21 is further provided with locking
means in the form of a spring-bias lock pin 56 which is
spring-biased inside the rectangular passage 29 by a spring
57 whereby to lock the support rod with the sleeve at one or
more predetermined positions as dictated by holes 58(see
Figures 7A and 7B)provided in a wall 59 of the support rod
22 opposed to the toothed edge section 23. Accordingly,
when the sleeve is displaced upwardly or downwardly it will
be arrested from the displacement when.the pin enters one of
the holes 58 delimiting the upward and downward trajectory
of the sleeve over the support rod 22. The lock pin 56 is
further provided with a retracting finger engaging head 59
to disengage the pin 56 from the hole 58. This pin is
constantly urged against the wall 59 of the support rod and
slides therealong during the displacement of the sleeve
thereabout.
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Referring now to Figure 8 it can be seen that a
support wheel 60 is also securable to the sleeve by support
means herein an attachment sleeve 61 welded to the sleeve 21
and projecting along the horizontal axis 54. The wheel 60
is secured to the attachment sleeve 61 by a lock pin 62.
The wheel 60 is mounted with its planar axis of rotation 63
extending parallel to the longitudinal axis 53 of the sleeve
21 and transverse to the axis 54. By removing the lock pin
62 the wheel is easily removable from the attachment sleeve
61 which is permanently secured to the open-ended sleeve 21.
Referring now to Figures 8 to 12, there is shown a
further embodiment wherein the rod connector 50 is
constructed differently than that illustrated in Figures 3
and 4. As hereinshown, the rod connector comprises a
horizontal lock flange 70 which is secured to the sleeve 21
and has an arcuate outer edge 71 (see Figure 9) provided
with two or more locking cavities 72 disposed therealong. A
pivot connecting flange 73 is secured to the sleeve 21 and
is disposed a predetermined distance above the horizontal
lock flange 70 and extends parallel thereto. Both the lock
flange 70 and pivot connecting flange 73 are provided with
through bores 70' and 73', respectively, to receive a pivot
pin 74 therethrough, see Figure 8. The horizontal rod 51 is
provided with a transverse bushing 75 at an end thereof and
constitutes a rod connector which is simply connected
between the lock flange 70 and the pivot connecting flange
73 by the pivot pin 74 as illustrated in Figure 8. As also
shown in Figure 8, the vertical connecting post 52 is herein
secured adjacent the connecting end of the horizontal rod 51
for release engagement with the hollow tubular end 55 of a
vertical corner frame member 11 of a scaffolding assembly.
The lock flanges 70, 73 permit the foot plates 24 to the
angulated at a desired angle independent from one another to
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adapt to the support surface on which they need to rest,
i.e. a narrow step or stair, etc.
A position arresting pin 76 interconnects the rod
connector or rod end 51' to the lock flange 70 when the pin
76 is received in one of the locking cavities 72. The
position arresting pin 76 is provided with finger engaging
means in the form of a top handle 77 to retract the
arresting pin from one of the locking cavities 72 for
disengagement therewith. Accordingly, the sleeve 22 and its
wheel 60 can be locked at different angles with respect to
the rod 51.
As can be seen from Figures 11 to 12, the
transverse tubular rod 51 is a telescopic rod 80 for
adjustment and for connection to scaffolding having vertical
corner posts 11, 11' spaced at different distances from one
another. This telescopic tubular rod 80 is capable of
adjusting the spacing between two vertical post connectors
52 at opposed ends of the tubular rod whereby to
interconnect two opposed leg support mechanisms 20 in a
tandem arrangement. The lock pin 81 interconnects the two
pipe sections 80' and 80" together, once the tubular rod 80
is of proper length. A handle 82 is connected to the
tubular rod 80 to facilitate the horizontal adjustment of
the tandem arrangement by simply providing a means to pull
up on the opposed leg support mechanisms whereby the sleeve
21 rides up on the respective support rods 22. A level 83
is secured to the top of the tubular rod 80 and indicates
the proper level of the rod. Of course a further level, not
shown, could also be mounted transverse to the level 83 to
provide for the leveling along the transverse axis or in a
transverse plane when the tandem arrangement is connected to
a scaffolding assembly.
With reference now to Figures 13 and 14 there is
shown the construction of a carriage frame 85 which is
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secured to carriage connectors 86 and 86' each secured to a
respective one of the wheel attachment sleeves 61 and 61'.
The carriage connectors 86 and 86' are each constituted by
an elongated flange 87 having a slot 88 therein to receive a
free end of a carriage frame connecting rod 89 attached
thereto by a connecting pin element 90 whereby to permit
displacement of the connecting end of the connecting rods 89
along the flange 86.
As hereinshown, the carriage frame 85 has a pair
of these connecting rods 89 and 89' connected to a pivoting
bar 91 which is pivotally connected at an end 92 to the
tubular rod 80. The other end of the connecting rods 89 and
89' are pivotally attached to a forward end of the pivotal
bar 91 on pivot connections 93 and 93', respectively. A
handle 94 is secured to the free end. of the pivotal bar 91'
whereby to provide ease of pulling a scaffolding secured to
the tandem arrangement. As shown in Figure 3, the wheels 60
of the tandem arrangement are disposed transverse to the
tubular rod 80 but these can swivel about the ends of the
tubular rod by adjusting the angle of the wheels by
withdrawing the lock pin 76 from engagement with the
horizontal locking flange 70 and displacing the wheels by
pushing laterally on the pulling handle 94 until the lock
pin 76 falls by gravity into the adjacent locking cavity 72
whereby both wheels can be locked at an angular position.
As shown in Figure 14, the wheels have been displaced 90
degrees about the ends of the tubular rod 80 whereby a
scaffolding structure connected thereto can be easily pulled
sideways.
Referring now to Figures 6, 7A and 7B, there will
be described the construction of the bottom support foot 24
which is secured at the bottom of the corner post 11 of a
scaffolding assembly. As hereinshown, the support foot 24
is formed from a rectangular metal plate which is configured
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to form a sliding plate 99 defining a contacting bottom wall
100 for sliding displacement on a support surface. This
slide plate 99 also has opposed outwardly angled end flanges
101 to permit the displacement of the scaffolding over an
irregular ground surface as these angled end flanges provide
for the sliding plate to slide or be guided over objects or
irregularities on a ground surface. They also provide for
the scaffolding to be easily displaced on a snow covered
surface.
Referring to Figure 6, it can be seen that the
center of the bottom wall 100 of the plate has a cavitated
section 102 whereby to permit the securement of a vertical
connector 103 for connection with the bottom end of a
vertical corner frame member 11, as previously described.
The vertical connector 103 is disposed substantially central
on the top wall 104 of the slide plate and provides
removable connection with the lower hollow end section 55 of
the corner frame member or post 11. It is provided with
spring-loaded prongs 105 to engage within the locking holes
106 provided in the end section 55 of the corner posts 11.
Such interconnection is well known in the art. Accordingly,
the present invention also encompasses a novel support foot
structure for connection directly to the scaffolding corner
posts.
Referring now to Figures 7A and 7B, there is shown
the slide plate as previously described but wherein the
support rod 22 is secured thereto at a lower end 22' by a
suitable connecting means 103'. Therefore, in order to
render a scaffolding assembly easily displaceable over a
ground surface, a tandem arrangement is secured to one pair
of corner posts of a rectangular scaffolding assembly and
the other pair of corner posts are connected directly to a
respective one of the sliding plates. Therefore, the entire
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assembled scaffolding structure is easily displaced over a
ground surface.
As above described, the present invention provides
an adjustable leg support mechanism which can be easily
assembled and disassembled in component parts for ease of
transport and storage. Also, some of the component parts
are considered to be optional, such as. the support wheels or
the carriage frame and the support wheels can be adapted to
the leg support mechanisms only when required. When it is
required to transport a scaffolding assembly the sleeve 21
is disconnected from the toothed edge of the support rod 22
and the sleeve is lowered therealong until the support wheel
rests on the ground surface. The support rod 22 is then
pulled upwardly above the ground surface and the sleeve is
relocked thereto to maintain the support foot or slide plate
24 elevated from the ground surface. The tandem arrangement
is then supported on its opposed support wheel 60. Of
course, these tandem arrangements can be connected to
opposed sides of a scaffolding structure wherein all corners
are adjustable and provided with wheels.
It is within the ambit of the present invention to
cover any obvious modifications of the preferred embodiment
described herein, provided such examples fall within the
scope of the appended claims.
