Note: Descriptions are shown in the official language in which they were submitted.
1,
DISMOUNTABLE FRAMEWORK
This invention relates to dismountable frameworks
which may be ~sed for a wide range of purposes
in forming temporary semi-permanent andJor readily
dismo~ntable structures, particularly but not
exclusively scaffolding, access towers or platforms,
temporary load supports e.g~ for locating concrete
shuttering or other falsework used in building,
constructin~ temporary buildings or shelters,
collapsihle freight containers and stilla~es,
~ 10 and the like.
In the past round section steel scaffold
- tubiny has been almost universally employed for
such purposes as the above, particularly by commercial
contractors and, thouyh in many respects this
material has proved satisfactory, it does have
practical disadvantages. The tubing is costly;
_ it is heavy unwieldy and difficult to store,
transport and handle particularly for small scale
applications e.g. domestic use, and in larye
scale applications such as substantial scaffolding
erections, it is not always safe and secure as
joining is normally effected by clamps in frictional
enyagement with the tubing ~eriphery. Insufficient
tightening or failure of even a single clam2,
which may be ~nder considerable loadinc~, can
cause a chain reaction leadiny to collapse of
the entire structure, particularly as the tubing
is not normally joined in end to end relationship
i.e. each joint forms a side by side connection
with forces transmitted in shear through the
clamp and bendiny and/or twisting moments L)eing
carried by the tubing.
The object of the present invention is to
provide a dismountable framewor~ which is easily
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and safely assembled and secured together without
special skills, which is cheap and adaptable,
which can be provided in a range of sizes including
those suitable for domestic or "do it yourself"
S users and which can he trans~orted and stored
in a minimum of space, and which is particularly
reliable and safe in use.
According to the invention there is provided
a set of members for constructin(3 a dismountable
framework com~rising a plurality of operatively
vertical elongate pillar members and a plurality
of elongate linking members, end portions of
said members being operatively interconnected
to form a framework, a first end portion of one
pillar member having a longitudinally projecting
tenon formation and a second end portion of another
pillar member having a socket formation opening
longitudinally thereof to receive said tenon
formation so that said pillar members are operatively
ali9ned in rectilinear end-to-end relationship;
end portions of the linking members each including
an apertured lug for engayement with said tenon
between said end portions in use to locate the
linking member whereby the latter member is located
in a vertical plane which includes a common axis
of both of said pillar members and said tenon
formation.
Preferably the second end portion is provided
with securing means comprising a retainin~ member
displaceable laterally of said end portion to
engage the periphery of the inserted tenon formation.
An embodiment of the invention with certain
variations and modifications is now more particularly
described with reference to the accompanying
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3.
drawings, wherein:
Figure 1 is an exploded perspective view
of part of a rectilinear framework;
Fic~ure 2 is an elevation oE an assembled
joint of the framework;
Figure 3 is a sectional plan view on line
3-3 of Figure 2;
Figure 4 is a perspective view of a modified
form of wedge;
Figure 5 is a perspective view of an end
portion of a further form of cross member;
~ Figure 6 is a perspective diagram of an access
tower;
Figures 7, 8 and 9 are perspective diagrams
of examples of other structures utilising the
invention; and
Figures 10, 11, 12 and 13 are perspective
views of respective additional members for use
with the invention.
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A set of members or constructing a light
duty rectilinear framework or use as scaffolding
or the like, will first be described. The dismountable
members ln the example shown in Figures 1 to
3, are of two kinds; vertical or pillar members
10 and linkiny members in the form of horizontal
or cross members 11, major elongate parts of
all of which consist of standard L section steel
angle and having means for interconnection at
each end thereof. For light duty applications
such as a small domestic access platform e.g.
for use on a staircase or for constructing a
work bench or the like each member can be an
effective length oE 75cm Eor ease of handlinc~
and storage and the angle section could be 2.5cm.
Wider ancl heavier section may be used e~g. 40
mm angle section in 3 mm gauge metal for heavy
duty frameworks and longer members may be employecl
2~
4.in some circumstances.
In Figures 1 to 3 only the lower end of an
upper pillar member lOa and the upper end of
a lower s~ch member lOb is shown toyether with
one end only of three cross members lla~ b, c
to connect with the pillar members at right angles.
Each pillar rnember 10 has a first operativel~
upper encl portion forming a male connection by
having a longitudinally extending tenon 12 welded
to a block or distance piece between the inner
faces of the angle webs and projecting centrally
through a square end abutment plate 13 which
is also welded to sai~ webs. In this example
tenon 12 is a circular section steel peg having
a flat or notch 14 on one side partway along
its free lenyth.
The second operatively lower end portion
of each pillar member 10 forms a female connection
includiny a mortice aperture 15, in this example
a circular bore in the centre of a square end
abutment plate 16 welc~ed to the webs of the angle
section.
The latter end portion is also provided with
securiny means comprising a stirruy member in
the form of a U bolt 17 located in a pair of
bores in one web of the an~31e so as to provide
a loop within the angle which embraces tenon
12 when the latter is inserted into mortice 15.
The outer ends of 1] bolt 17 mount a cross piece
18 permitting its effective lenyth to be selectively
adjusted and a captive wedge 19 acts between
the outer face of the associated anyle web and
cross piece 18 to draw the U bolt 17 into tiyht
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positive engagement with the notch 14 of tenon
12 to secure the assembly.
In the above manner a pillar of any desired
length can be built up using successive pillar
n~embers 10 and tllese are secured in aligned end-to-end
relationship so that down thrust is transmitted
directly along their length. It will be observed
that the inherent weight-bearing ability of a
pillar so formed does not in any way depend on
1~ the security or clamping enyagement of the securing
means with the tenons 12, indeed Eor some applications
securing means may not be necessary.
.
~ ach cross piece 11 is formed from angle
generally as described with reference to members
10 and both end portions of each cross member
comprise a weldeA on end abutment plate 20 and
an apertured lug 21 projecting longitudinally
beyond plate 20, this lug being welded to the
upper horizontal web of the angle either below
(21c) or above (21a, b) the latter.
Where cross members are to be jolned to the
assembled pillar their lugs 21 are positioned
on tenon 12 in sequence e.g. as illustrated in
Figures 1 to 3 where a three-way connection is
shown, before the tenon is engaged with the next
upper pillar member lOa~
The wedge 19 is formed from flat plate and,
as best shown in Figure 2, has one edye cut o~t
to form a notch between upper and lower end stops
30a, 30b which retain the wedge captive with
the U bolt 17. An upper part of the notch includes
an inclineA edge face 31 enabling the U bolt
to be tightened by driving the wedge downwards
6.
to react with cross piece 18, elongated slots
18a in the la~ter permit~ing it to tilt on bolt
17. The lower part of the notch is deeper and
not inclined to permit maximum inward movement
of the U bolt for freeing ~he tenon 12. In a
modification shown in Figure 4 the end stops
30a, 30b are ~ridged by a bar 32 integral with
or welded onto said stops, so strengtheniny the
wed~3e and making its captiv~ retention on cross
piece 18 more positive.
- Wedge 19 is pre~erably distinctively coloured
so that a very quick visual inspection of the
assemble~ framework will shown whether it has
been tightened into place (or has become loosened
or displaced in service). In any event the wedge
will tend to drop to the securec~ position in
use which will retain the tenon automatically
even if the we(~ge has not been fully tightened
and, as explained above, the integrity of the
structure does not depend on this tightening,
downward loading on the cross members 11 and/or
upper pillar member l~a is transmitted directly
to the top of pillar member lOb and lateral forces
on the latter are transmitted from members ll
directly to the tenon 12, the securing means
carries none of these forces.
Instead of the adjustable U bolts 17 a simple
link or hook-shaped bar, or a screw clamp, could
serve as a retaining member of the securing means,
and it will also be appreciated that various
forms of mortice and tenon could be employe~
though for ease of manufacture and availability
of material, the round peg and circular apertures
are preferred. Thus, oval, square or rectangular
section mortices and tenons or other config~rations
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7.
might be employed in some applications and the
section and shaping of the members themselves
can be widely varied.
For some forms of framework a fourth horizontal
cross memher may be required to connect with
the pillar assembly shown in Figures 1 to 3.
Figure 5 shows an end portion of a fourth cross
member lld which can be connected at right angles
to members lla, llc to form a continuation of
member llb. ~his member has an apertured lug
~ 21_ to enga~e tenon 12, and a slot 40 cut o~t
of its upper web to provide clearance for the
wec~ye 19. A pad 41 is welded to the vertical
web of member lld in the region of slo~ 4n for
reinforcement.
The strength and stiffness of the framework
can be added to by use of diagonal bracing to
form a triangulated rectilinear structure and
Eigures 6 to 9 are ~erspective diagrams of four
examples of the many forms of structure which
can be provided using the invention.
Figure 6 shows a simple free-standing access
platform or tower 4~ using four pillar assemblies
made up of sets of pillar members 10. The lowest
portions of these assemblies are short pillar
members 50 provided with adjustable levelling
feet 51 shown in detail in Eigure 12. Each side
frame of the tower includes horizontal rnembers
11 ancl is bracec3 in the vertical plane by diagonal
sloping linking members 52 extending from the
tenon at the lower end oE a lower pillar member
to that at the upper end of the parallel pillar
member on that side, members 52 having angled
lugs at each end for this p~rpose. Additional
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rigidity is provided by horizontal diagonal linking
members 53 connecting opposite corners o~ the
frame, and the pillar members in this exarnple
are also provided with intermediate attachment
p~ints within the web angle to receive further
horizontal cross braces 54 or, at the top level,
hori~ontal members 55 forminy a safety rail around
a deck 56. Toe boards 57 are also shown.
pair of horizontal locking members 58, shown
in detail in Figure 10 are used to finish off
the tower these having socket formations 59 at
~ each end at right anyles to the length of the
member with securing ~ bolts and wedyes to engaye
the uppermost tenon formations of the pillar
assemblies.
Figures 7, 8 and 9 are diagrams of three
of many and varied forms of frarnework structures
which may readily be assembled using the inveT-tion.
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Figure 7 shows the brid~ing of a substantial
span ~etween two spaced towers 60, 61 similarto those shown in Figure 6, the righthand tower
61 being extended u~wards to a working platoform
62, for example at first floor window level.
To add to the support of the horizontal span
of this structure a further forrm of member is
used, a diagonal cantilever member 63 (see Figure
ll)o This member has lug 64 angled to be horizontal
at its lower end and a tenon formation 65 (as
on the pillar members) angled to be vertical
at its upper end to receive c,ther mernbers. To
add to its rigidity the lower end is also provided
with a downwardly extending abutment 66 haviny
a vertical face to locate ayainst a face of the
adjoining pillar member.
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9.
Also shown is a diagonal outrigger or buttress
member 67 (see Figure 13~ having angled lugs
68 at each end which extend horizontally in use
to connect with respective tenon formations at
different levels. Member 67 has an upwardly
extendinc3 abutment 69 at its upper end with a
vertical face to locate against a face of the
adjoinin~ pillar member.
In Figure 8 a free standing tower framework
65 is shown with a work platform 66 at second
- story level cantilivered outward from opposite
sides of the main tower using cantilever members
63, stability and support being provided by ground
engaging feet 51 mounted on outrigyers ~elow
~he cantilevered parts of platform 66, the outriggers
using buttress members 67 secured by locking
members 58.
Figure 9 shows another form of framework
70 providing a longer work platform 71 at hi~3h
level using cantilever members 63, one end of
the platform being supported on the roof of a
single story building 72.
The different types of member may each be
distinctively coloured to facilitate assembly
and dia~rams of common types of assembly listing
the members required to build it may be provided.
It is contemplated that such diagrams and listing
might be provided for standard or for special
purpose structures using a computer which will
also be programmed to provide calculations of
safe working loading, and, if required, costiny
of the members needed either on a purchase or
hire basis.
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10 .
~ sing such a diagram the structures can be
safely anc] reliably assembled even by unskilled
or inexperienced labour, e.g. for "d~ it yourself"
repairs or maintenance by householders themselves.
As the structure is self-supporting and positively
locating from the ground up it can be safely
stood on and climbed up as erection proceeds.
The use of members to ma~e up each side of
a rectilinear triangulated framework or truss
whose loads are transmitted in a common vertical
plane along their axes, and the manner in which
the loads are all carried to the axially centred
tenons without reliance on the integrity of securing
or fastening means or application of off-centre
loadings thereto as is the case when tubular
or other members are secured side by side enables
stabLe free stanc3ing structures to be provided
avoiding the need in many cases to "tie" them
~ in to a building, and the ability to construct
simply and safely cantilevered or bridging structures
over a wide span means that access to many locations
otherwise awkward to get to can be readily provided,
and that room can be left at ground level for
work and for unobstructed and safe passaye e.g.
along pavements or footways or ~o the doors or
shop winclows of a buildiny beiny worked on.
Different weights or gauges of member may
be employed in the same structure, for exarnple
a heavier gauge pillar member could be used in
the lower parts of a tall tower or scaffoldiny
or for the formation of a hollow yirder or cantilever
platform to span a substantial distance. Additional
members can be purchased and added onto an existin~
system as required and it is anticipated that
there will be considera~le cost saving over conventional
tubular scaffoldiny and clamps, for example steel
angle equivalent in service to standard scaffold
tu~iny costs, by weight, less than half the price
of the latter and is in any event much liyhter
in weight for a yiven length~ 40mm angle of
3mm gau(3e steel weighs 1.81Kg per metre lenyth
while the same length of standard steel scaffold
tube weights about 3 Kg. and will no. withstand
the same loading.
Other members and accessories includin~ special
purpose fittings can be incorporated in the set
of members or adapted to interconnect therewith,
for example access ladders or steps, telescopic
legs or pillars, ground engayiny wheels for moveable
towers, staging or stillages, hoists or lifts
for materials, doors or shutters for collapsible
transport or storage racks or container frames,
conveyor tracks etc.
Distal portions of the tenons 12 may each
be provided with a throuyh cross bore to receive
a securing bolt or loc~; e.g. to prevent unauthorised
dismantling or temperinc3 with an assembled structure.
