Note: Descriptions are shown in the official language in which they were submitted.
CA 022128~9 1997-08-13
Scaffoldinq system
The present invention relates to a scaffolding system, and more particularly to a
side/top protecting/shielding device for scaffoldings or similar structures.
It is often desirable to provide temporary weather shelters in situ, e.g. at a
construction site or in connection with maintenance, renovation or painting activities
on large objects such as buildings, vessels, tanks etc. Especially during the winter
time it is important to provide protection against low temperatures, wind and
humidity (rain, fog). Furthermore, under erection/maintenance of buildings situated
in frequented areas (cities) it is also requested to protect the by-passing traffic and
pedestrians against accidents due to falling objects, dust, grease and even noise
caused by surface treatment (sand blowing) of buildings' walls.
Consequently, several means/systems are used and proposed to be used toprovide such protecting/shielding devices in connection with scafloldings.
Different means/systems are already known based mostly upon provision of
suspended cladding, such as polyethylene sheeting or polyvinyl chloride fabric
extending along the erected scaffolding structure. Several ways of attaching thefabric to the scaffolding structure, means of fastening and stretching such fabrics
are known from numerous patent publications dealing with problems of adequate
enclosure of the working site and requests for flexibility with regard to size/shape
and conditions of the applied cladding material.
Thus DE 4125664 discloses, in combination with a scaffolding, a plurality of
shielding sheets attached to the tubular horizontally extending scaffolding members
by means of a hooks arrangement. In order to provide a sturdy and weather/dust
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proof construction the shielding sheets are provided as corrugated sheets fastened
within a rigid frame offering, at least along its sides, a possibility of elastic "sealing"
and due to the corrugation of plates also a simple overlap of the side-by-side
arranged elements.
There are three maJor disadvantages connected to the disclosed shielding system.First of all because of fastening of the shielding sheets by means of a hook
arrangement to horizontally extending scaffolding pipes no appropriate sealing
between the sheets in the vertical direction can be assured based on overlap of the
adjacent corrugated sheets.
Secondly use of corrugated shielding sheets and complicated system of rigid
framing and fastening hooks does not allow for an appropriate cleaning of the
surfaces for sand and other surface treating materials and consequently a high
degree of recuperation of such materials.
Finally, the described shielding system is in particular designed for shielding planar
objects, as the vertically oriented sealing lip interconnecting the panels will limit the
maximum allowable angular position between these.
JP-A-1 187256 discloses a scaffolding system comprising upright frames arranged
in parallel where adjoining posts of such frames are interconnected by lateral frame
bodies with linking parts and pins. The frame bodies may be in a square form andfilled with a sound absorbing material.
The purpose of the system is to simplify the erecting and dismantling work as the
system does not involve the use of bracings. This is obtained by interconnectingparallel, upright frames by means of lateral frame bodies, as the frame bodies are
able to withstand the forces normally taken up by the bracings. Thus, the frame
bodies makes a substantial part of the structural strength of the scaffolding system,
and are accordingly connected to the vertical posts by links able to take up forces
in the scaffolding structure.
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As the frame bodies are designed for taking up structural forces, these are quite
heavy and therefore a lot of effort are required both in handling and
assembling/dismantling operations. Further, the scaffolding system do not provide
that controlled climate and working conditions may be obtained, in particular when
performing work on curved objects.
AU-A-573 869, discloses a scaffold assembly including a vertically extending
scaffold frame and planar guard panels mounted to said frame. The guard panels
are mounted to said frame by a plurality of brackets secured at predetermined
positions on the frame, said brackets extend between the frame and the guard
panels and are provided with a support portion which locates and supports the
panel relative to the frame. This solution does neither relate to the provision of
controlled climate conditions within the scaffolding as the guard panels includeopen mesh panels, nor does this solution describe the ability to encapsulate curved
objects.
Thus, none hitherto known devices/means are complying with the complex requests
to such devices regarding economics, quality and life span of conducted
maintenance work and surface treatments on one hand and environmental aspects
and impacts on the other hand. Thus, apart from the above mentioned requested
protection aspects, it is furthermore desirable to provide a scaffolding system
offering also possibilities for collecting dusVapplied cleaners, filtration, recirculation
of such materials etc.
It is therefore an object of the invention to provide a new and improved scaffolding
system avoiding the above shortcomings and ensuring controlled climate and
working conditions.
Another object is to provide a light weight scaffolding system of a simple
construction requiring no special (heavy) equipment for erection/dismantling of the
system.
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Still another object is to provide a complete mobile scaffolding system allowing for
easy disassembling/assembling and transfer from site to site of scaffolding
members and the necessary auxiliary equipment, comprising handle-proof elements
and a easy and reliable disassembling/assembling fastening/supporting system.
These and other objects and features of the scaffolding system according to the
invention are met by provision of a scaffolding system as claimed in the
accompanying patent claims 1 - 9.
The present invention will be described in more details and will be more apparent
from the following description and drawings, Figs. 1-6, where
Fig. 1 is a schematical perspective view of the scaffolding system according
to the present invention,
Fig. 2 shows in a cross-sectional view along line I-I in Fig. 1 schematically a
sheet member employable in the scaffolding system.
Fig. 3 shows in perspective a sheet member joint with a sheet
fastening/supporting system,
Fig. 4 shows a vertical cross-sectional view through the fastening system
shown in Fig. 3,
Fig. ~ shows a horizontal cross-sectional view through the fastening system
shown in Fig. 3,
Fig. 6 shows in a cross-sectional view along line A-A in Fig. 5 a horizontally
sealed joint between two sheet members.
Referring to the drawings, and particularly to Fig. 1, a storage tank, e.g. a large fuel
tank 1, is shown schematically in a perspective view exhibiting also a scaffolding
system under erection/dismantling around the tank. The scaffolding comprises a
conventional frame 2 of vertically and horizontally interconnected tubular members
forming a "skeleton" for the present scaffolding system. According to the present
invention a plurality of sheet members 3 are attached (fastened) to the tubular
CA 022128~9 1997-08-13
members in a way ensuring a leakage proof tight connection so that an "air
conditioned" climate can be established between the provided scaffolding walls and
the storage tank. The appropriate climate (temperature, humidity etc.) is provided
by means of a (mobile) air conditioning unit 5 supplementary provided with high
capacity fans so that even a desirous degree of vacuum could be ensured. An
emergency exit 4 is provided for the workers to evacuate the site if necessary.
The principle of "hermetic" encapsulation of the objects is also illustrated in Fig. 2 in
a cross-sectional view taken along line I-I in Fig. 1.
The storage vessel 1 surrounded by a conventional scaffolding skeleton 2 being
additionally provided with sheet members 3 is further equipped with a roof 6
possibly extending as an additional side wall 7 offering a shelter for the installed air
conditioning equipment 5. The roof 6 and the auxiliary side wall 7 can
advantageously be provided as a fire proof fabric (sheet) in order to increase the
safety for the surroundings.
Figure 3 shows in perspective, a vertical tubular member 9 forming part of the
scaffolding frame onto which there is attached a sheet fastening/supporting system
8 interconnecting two pair of sheet members 3 (only the lower pair 3, 3' is shown in
this figure).
The system 8 is shown in an vertical cross-sectional view in Figure 4 and includes
one lower sheet member 3 and one upper sheet member 3". Further, the system
comprises a clamping device or combi-coupling 10 attached to the vertical tubular
member at its one end, supporting a bracket 12 by a threaded fastener 24 at its
other end. To increase the torsional stiffness about the axis of the fastener 24, a
yoke plate 11 is arranged between the bracket 12 and the vertical tubular member9. The yoke plate 11 is securely fixed to the bracket 12 by appropriate means aswelding, gluing or any mechanical fastener (not shown).
With reference to Fig. 5, it will be seen that the bracket 12 supports two link arms
141 14' by pivotal connections 13, 13'. The link arms are provided with recesses 19
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at their outermost ends, where said recesses are adapted to support the sheet
members 3. The recesses consists of two spaced apart abutment walls 21, 21
interconnected with a bridging element 23, dividing the recesses into an upper
recess 28, and a lower recess 29. The bridging element 23 is provided with a slot
20. A wedging element 15 is adapted to correspond with the slot 20 and one
abutment wall, forcing the sheet member into firm abutment with the opposite
abutment wall to firmly hold and lock said element when properly engaged. It will
be seen that the outer abutment wall 21 is provided with sealing elements 26, 27 at
its interior faces. This feature provides that when engaging the wedging elements
15 the sheet members are brought into a sealed abutment with said wall.
It will be seen in Fig. 3 that the lower recess 29 have a greater depth than theupper recess 28. This feature is essential when installing the sheet members 3.
When installing a new sheet member, the upper edge of the member is simply
brought into engagement with the recess 29. Then the member is lifted high
enough to be engaged with an upper recess in an supporting/fastening system
arranged at the lower edge of the sheet member (not shown). At this stage the
sheet member is self suspended. This feature allows that several sheet members
may be installed in a continuous operation, followed by the locking operation
comprising the engagement of the wedging elements 15. Thus, this feature
contributes to a rapid and easy assembling/dissassembling procedure as handling
elements and locking them may be performed as two separate operations, by
different crews or as succeeding operations by one crew.
The pivotal connections 13, 13' of the link arms 14, 14' allows the sheet members 3,
3' to be interconnected within a large variety of interrelated angular positions. The
resulting gap between the sheet members 3, 3' may be covered by a vertical
extending sealing element 16 having bulbous end sections 17 that are brought into
engagement with recesses 18 formed at the end sections of the sheet members.
The sealing element 16 is preferably formed out of a material having elastic
properties, such as plastic or rubber, but it should be stated that any appropriate
sheet material may be employed.
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Fig. 6 shows a sealed connection between an upper sheet member 3" and a lower
sheet member 3. The connection comprises a sealing plate element 24 attached
at the lower part of the upper member 3". The lower part of the plate element 24 is
provided with an sealing element 25 at its inwardly facing side, and is brought into
firm abutment with the outer side of the sheet member 3.
The sheet members may advantageously be of any sandwich structure, comprising
at least one layer made out of a foamed material and at least one hard and smooth
outer face. The outer face(s) may be formed out of materials as fibre glass,
appropriate resin materials, steel or aluminium. The sheet members are preferably
surrounded by a frame structure that may be made out of aluminium, giving the
members good strength and handling properties.
The sheet members may preferably be made of a new emerging material,
aluminium or Al-alloy foam offering an ideal combination of the requested
properties. The inherent properties of this material, light weight, excellent thermal
and sound insulation, can be further enhanced during the manufacturing process
adding still new and desired features to the product. Apart from the possibility to
provide a smooth surface and reinforced periphery of the sheets, it is possible by
applying e.g. nitrogen or even some of the other fire inhibiting gases in the process
of manufacturing the foam to provide the scaffolding sheets having up to 80%
porosity in the form of closed pores filled with fire inhibiting. Such gases being
released upon a possible fire on the maintenance site resuiting in collapse (melting)
of the sheets, will reduce the danger of major fires due to an instant fire
extinguishing effect from the released gases.
The above described and particular embodiment of the scaffolding system
according to the present invention offers several advantages compared to the
hitherto known and commercially applied scaffoldings. The fastening/supporting
system of the sheet members offers easy and fast assembling/disassembling
operations, as good sealing properties are maintained.
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Thanks to the complete encapsulation of the objects the actual maintenance of e.g.
storage tanks, bridges, pipes etc. can take place even during the winter time
(monsoon time) "in situ" ensuring:
a) increased "life span" of the painting due to the controlled temperature and air
humidity,
b) blowing agents (sand) can easily be recuperated, something which
represents a severe reduction of deposited (wasted) sand and applied
surface treating materials (low humidity for sand blasting, higher for painting
operations)
c) almost 100% collection of waste materials due to the possibility to create
underpressure conditions,
d) high degree of flexibility and mobility of the scaffolding system based on light
weight modules inclusive of auxiliary air-conditioning equipment which could
easily be dismantled and transported to the maintenance locations.
e) employing sheet members with foamed layer, i.e. members having low
thermal conductivity, will contribute to a decrease in the energy demand for
obtain designed temperatures within the shielding system, thus smaller
heating equipment may be employed, and also energy costs may be reduced.
AMENDED SHE~T
