[0001] This invention relates to scaffolding systems.
[0002] Scaffolding systems generally consist of interconnected horizontal and vertical members.
The horizontal and vertical members may both be in the same form, e.g. tubular members
or the horizontal members can take the form of a space frame comprising two horizontal
chord members interconnected and spaced by bracing members.
[0003] Scaffolding systems have a multiplicity of uses, a particularly common one of which
is to support beams, the beams being used, for example, as a work platform or to support
concrete cast thereabove. Scaffolding systems employed for this purpose have to have
good structural integrity and a problem which arises with those systems where space
frames are employed is how to connect these to the vertical leg members to ensure
this.
[0004] In one known arrangement, the space frames are connected between adjacent vertical
members by inserting pins attached to the ends of the chord members of the space frames
in sockets provided on the vertical members. A latch member in the form of a plate
pivotally mounted on the space frame is then rotated into a position in which it is
held between the bottom edge of the socket and the space frame and so serves to prevent
the space frame from upward movement relative the socket which would release the pin
therefrom. The latching means plate is carried on a face of the space frame and is,
therefore, vulnerable to damage both when the system is being transported in its dismantled
state and when it is erected and in use.
[0005] The latching plates do not prevent all movement of the pins in the sockets and so
do not provide a rigid connection. They are furthermore vulnerable to incorrect positioning
on erection and/or dislodgement in use, in which case they will cease to be effective
in any way.
[0006] Attempts have been made to provide a method of attaching space frames which does
not suffer from these disadvantages and which provides a rigid and strong connection
between the space frame and the two leg members between which it is secured. For example,
British Patent Application 2234776 describes space frames with end vertical members
of T-shaped profile which locate in T-shaped slots provided in the leg members, the
two then being bolted together. The problem with this is the need for specially shaped
parts which adds to the expense of the system. Furthermore, both in this and in other
suggested arrangements, bolting is required. This makes erection a laborious and time-consuming
operation and the nuts and bolts can be relatively easily lost.
[0007] A further disadvantage of all the above-described arrangements is that they do not
readily permit the attachment of bracing members across the bays formed by the vertical
leg members and the horizontal space frames. Specifically, they do not allow the bracing
members to be connected at the points of attachment of the space frames and the vertical
leg members. The addition of bracing members at locations off-set from these attachment
points can cause the introduction of secondary stresses into the system.
[0008] European Patent Application 0427448 (relevant under Article 53(3)) describes a scaffolding
system comprising a diagonal brace with a transverse pin for engaging an aperture
in an end fitting of a horizontal cross-member. The pin has an internal snap-action
latch which a hooked projection end to engage a complementary configuration on the
eye.
[0009] Danish Patent 117987 describes a scaffolding system with horizontal space frames
including a pair of spaced horizontal chords. At each end of both chords a vertical
pin is provided, which pins are received in sockets carried on vertical uprights of
the system. Each pin carries therein a rivet shaped part biassed by a spring to protrude
from the pin when positioned within a socket and thereby retain the pin therein.
[0010] In accordance with the invention, a scaffolding system has a plurality of vertical
legs, each provided with socket members along the length thereof, and a plurality
of space frames, each of which comprises two horizontal chord members interconnected
and spaced by bracing members and first attachment means at either end of at least
one of the chord members whereby the space frame may be connected between two adjacent
vertical legs, the first attachment means comprising a pin for insertion into the
socket of a socket member, releasable latch means carried on or in the pin which,
when the pin is inserted into the socket of a socket member, wherein each socket member
comprises a ring having a socket-defining aperture therein for receiving a first attachment
means pin characterised in that the ring of each socket member is mounted on the associated
vertical leg such that second attachment means in the form of a C-shaped end fitting
can locate around a portion of the ring.
[0011] The advantages of this arrangement are that the socket members can be used with either
of two different types of attachment means. Further the ring form of the socket members
allows one socket member to be used with both types of attachment means simultaneously.
For example, if the chord member of the space frame having first attachment means
is connected to a socket member, another part with a C-shaped fitting can also be
attached. Conversely if, as is preferred, the second chord member has second attachment
means at either end, another part, a particular example being a brace, with pin-form
attachment means can be secured at the same socket members as the second chord member.
[0012] The other chord member of each space frame may also be provided at each end thereof
with first attachment means. However, preferably, the other chord member of each space
frame is provided at either end thereof with second attachment means comprising a
C-shaped end fitting which locates around and cooperates with a portion of a socket
member. It has been found that, so long as one of the chord members of each space
frame is provided at each end thereof with the first, pin, attachment means, sufficient
system stability results from the use of the second, simpler, attachment means at
the other chord. The result is a very economical system which is easy to erect and
dismantle. A further advantage is that, as will be further described below, the C-shaped
end fitting when located around and cooperating with a particular socket member does
not interfere with or prevent the securement of a first attachment means to that socket
member. Diagonal bracing members provided at an end thereof with a first attachment
means can, therefore, be secured to the socket member. In this way the introduction
of secondary stresses into the system is avoided. Moreover a space frame may be supported
by locating the C-shaped end fittings first so facilitating insertion of the pins.
[0013] The socket members are suitably arranged in spaced groups, each group comprising
two sets of four socket members equi-angularly spaced around a vertical leg, the sets
being spaced apart by a distance approximately equal to that between the chord members
of a space frame.
[0014] In a preferred embodiment each socket member comprises a pair of spaced plates, each
connected at one end to a vertical leg and formed with an aperture therein dimensioned
such that a pin of the first attachment means may be passed therethrough, the apertures
being aligned. The ring is secured between the plates with its axis aligned with the
apertures therein. The outer radius of the ring is approximately equal to the radius
of the inner face of a C-shaped end fitting of the second attachment means. The distance
between the ring and the vertical leg to which the socket member is secured is equal
to the width of an arm of the C-shaped end fitting. The result is that axial movement
of a chord member of a space frame provided with the second attachment means relative
the vertical legs between which it is connected is prevented. By also making the spacing
between the plates of a socket member approximately equal to the thickness of an arm
of the C-shaped end fitting, movement of the chord in the horizontal plane is prevented.
[0015] The first attachment means may include biassing means which, when the pin is inserted
into the socket of a socket member, automatically urges the latch means towards a
locked position in which a portion thereof latches against the socket member to retain
the pin therein and to prevent movement of the pin within the socket. The first attachment
means are then automatically operated so that erection of the system is simpler and
quicker. They do not require any bolts nor indeed any separate parts which could easily
be lost. A rigid and secure connection is provided in which movement of the pin within
the socket is prevented and so too, therefore, is movement of the space frame relative
the vertical leg to which it is connected. Furthermore, as the latch means is carried
on or in the pin, it can be located so that, in use, it is positioned between the
vertical member and the space frame and is, therefore, protected.
[0016] Preferably the latch means is carried in the pin with the portion thereof which latches
against the socket protruding from the pin. The risk of damage to the attachment means,
not only when a scaffolding system is erected and in use but also when it is dismantled
and being transported, is, therefore, minimized.
[0017] Suitably the biassing means comprises a spring carried in the pin.
[0018] The pin is preferably dimensioned such that it will form a close fit with the socket
member to thereby provide a rigid and strong connection of the space frame and vertical
member.
[0019] The invention will now be further described by way of example with reference to the
accompanying drawing in which:-
Figure 1 is a side view of part of a scaffolding system in accordance with the invention;
Figure 2 is a plan view of the scaffolding system part of Figure 1;
Figure 3 is a side view of another part of the scaffolding system of Figure 1;
Figure 4 is a side view of a leg of the scaffolding system of Figure 1; and
Figure 5 is a side view of a first attachment means of the scaffolding system of Figure
1 which illustrates the operation thereof.
[0020] The scaffolding system comprises a plurality of vertical legs 2 interconnected by
space frames 4. The space frames 4 comprise two horizontal chord members 6 interconnected
and spaced by bracing members 8 which may be vertical, as shown, and/or diagonal.
[0021] The legs 2 are provided with a plurality of groups of sockets 10 along their length,
each group consisting of two sets of four equi-angularly spaced sockets 10. The spacing
between each set of sockets 10 is approximately equal to that between the two chord
members 6 of the space frames 4. The number of groups of sockets 10 provided will
obviously depend on the length of the leg 2. As illustrated in Figure 4, only one
group of sockets 10 may be provided.
[0022] Each socket 10 consists of a pair of plates 12 welded, see 14, to the leg 2. Aligned
apertures 15 are provided in the plates 12 and a ring 16 whose inner diameter is equal
to that of the apertures is welded, see 18, between the plates 12 with its axis aligned
with those of the apertures 15. The set of sockets 10 which are uppermost has the
apertures 15 in the upper halves of the plates 12, whilst the set which is lowermost
has the apertures 15 in the lower halves of the plates 12.
[0023] Figure 1 shows the top chord 6a of a space frame 4. This is provided at either end
with first attachment means 20 shown in detail in Figure 5. The first attachment means
20 comprises a body having a generally annular boss 22 by which it is welded, see
24, to the end of the chord member 6a. An integral bracket portion 26 of the boss
22 mounts a hollow pin 28 which extends transversely to the plane of the space frame
4. A hook-like latch member 30 is mounted in the interior of the pin 28. The latch
member 30 has a hooked projecting nib 32 which protrudes through a slot provided in
the wall of the pin 28.
[0024] The other end of the latch member 30 is pivotally mounted on, for example, a Bissel
pin 34 connected between opposite walls of the pin 28. A torsion spring 36 is mounted
between an internal surface of the pin 28 and the latch member 30 and around the pivot
pin 34. The torsion spring 36 urges the latch member 30 to the position illustrated
in Figure 5 in which the nib 32 projects from the pin 28.
[0025] Adjacent the pivot pin 34, the latch member 20 has an integral operating arm 38 which
projects laterally from the pin 28 through a slot in the wall of the latter as shown
in Figure 1. The operating arm projects towards the chord member 6a of the bracing
frame 4 and is disposed between a pair of protective ribs or flanges 40 on the latching
member 20.
[0026] When the pin 28 of the latching member 20 is inserted through apertures 15 and ring
16 of a socket member 10, the nib 32 is pushed into the pin 28 against the bias of
spring 36, the nib 32 being provided with a tapered leading surface to facilitate
this movement. When the pin 28 has been fully inserted, the spring 36 will cause the
nib 32 to revert to the position in which it projects through the slot in the pin
28 so causing it to engage the plate 12 on the opposite side of the socket member
10 to that from which the pin 28 was inserted. The pin 28 will, therefore, be positively
retained within the socket member 10.
[0027] Furthermore, as illustrated in Figure 5, the pin 28 is a close fit within the ring
16, whilst the distance between the bracket 26 and the tip of the nib 32 is equal
to that between the two plates 12 of the socket member 10. Thus a rigid connection
will be provided at which there will be little movement of the parts.
[0028] To release the space frame 4, the arm 38 is pressed towards the chord 6a to cause
the nib 32 to be withdrawn into the pin 28 against the bias of the spring 36. Pin
28 can then be withdrawn from the ring 16.
[0029] Figure 3 shows the lower chord 6b of a space frame 4. This is provided with second
attachment means 42 at either end thereof. The attachment means 42 comprises an annular
boss 44 by which it is welded, see 46, to the end of the chord member 6b. Integrally
formed with the annular boss 44 is a C-shaped end fitting 48 with an inner circular
face of the same radius as the exterior of ring 16. The width of the outer arm 50
of the C-shaped end fitting 48 is equal to the distance between the ring 16 of the
socket member 10 and the face of the leg 2 to which the socket member 10 is attached.
The thickness of the C-shaped end fitting is equal to the distance between the plates
12 of the socket member 10. The result of this is that the C-shaped end fitting 48
will locate around the ring 16 with its far arm 50 held in the plane transverse to
the axis of the leg 2 by the plates 12, the ring 16 and the leg 2. The prevents any
movement of the end fitting 48 within this plane and thus provides a secure and rigid
connection between the lower chord 6b and the leg 2.
[0030] The form of the socket members 10 and of the second attachments means 42 allows a
bracing member 52 to be additionally attached between the point of connection of a
leg 2 and the lower chord 6b of a space frame 4 and a head or base jack carried on
an adjacent leg. The diagonal bracing member 52 is provided at one end thereof with
a first attachment means 20. The pin thereof can be inserted through the ring 16 without
interference from the end fitting 48 of the second attachment means 42 provided at
the ends of the lower chord 6b of the space frame 4. By attaching the diagonal bracing
member 52 at the point of connection of the space frame 4 and vertical leg 2, the
introduction of secondary stresses into the system is avoided.
[0031] The space frame 4 can be easily and securely attached between two vertical legs 2
by pinning its upper chord 6a to two aligned socket members 10 with the first attachment
means 20, and latching its lower chord 6b between two further aligned socket members
10 by locating the end fittings 48 of the second attachment means provided at either
end thereof around the rings 16 of the socket members 10. It will be appreciated that
the opposite arrangement could be employed, that is, first attachment means could
be provided at either end of the lower chord 6b with second attachment means being
provided at either end of the upper chord 6a. Diagonal bracing members 52 can be attached
at those socket members where a space frame chord is connected by second attachment
means. Furthermore, the diagonal bracing members could instead be provided with a
suitable form of the second attachment means so that these could be attached at socket
members where a space frame chord is secured by first attachment means.
1. A scaffolding system having a plurality of vertical legs (2), each provided with identical
socket members (10) along the length thereof, and a plurality of space frames (4),
each of which comprises two horizontal chord members (6) interconnected and spaced
by bracing members (8) and first attachment means (20) at either end of at least one
of the chord members whereby the space frame (4) may be connected between two adjacent
vertical legs (2), the first attachment means (20) comprising a pin (28) for insertion
into the socket of a socket member (10), releasable latch means (30, 32) carried on
or in the pin (28) which, when the pin (28) is inserted into the socket of a socket
member (10), wherein each socket member (10) comprises a ring (16) having a socket-defining
aperture (15) therein for receiving a first attachment means pin (28) characterised
in that the ring (16) of each socket member (10) is mounted on the associated vertical
leg (2) such that second attachment means (42) in the form of a C-shaped end fitting
(48) can locate around a portion of the ring (16).
2. A scaffolding system as claimed in Claim 1 wherein first attachment means (20) are
also provided at each end of the other chord member (6) of each space frame (4).
3. A scaffolding system as claimed in Claim 1 wherein the other chord member (6) of each
space frame (4) is provided at either end thereof with second attachment means (42)
comprising a C-shaped end fitting (48) which locates around and cooperates with a
portion of a socket member (10).
4. A scaffolding system as claimed in any preceding Claim wherein the socket members
(10) of each vertical leg (2) are arranged in spaced groups, each group comprising
two sets of four socket members (10) equi-angularly spaced around the leg (2), the
sets being spaced apart by a distance approximately equal to that between the chord
members (6) of a space frame (4).
5. A scaffolding system as claimed in any preceding Claim wherein each socket member
(10) comprises a pair of spaced plates (12), each connected at one end to a vertical
leg (2) and being formed with an aperture (15) therein dimensioned such that a pin
(28) of the first attachment means (20) may be passed therethrough, the apertures
(15) being aligned.
6. A scaffolding system as claimed in Claim 5 as dependent on either Claim 3 or Claim
4 wherein the distance between the plates (12) is equal to the thickness of at least
the arms (50) of the C-shaped end fittings (48).
7. A scaffolding system as claimed in Claim 5 or Claim 6 wherein the ring (16) of each
socket member (10) is secured between the plates (12) thereof with its axis aligned
with that of the apertures (15) therein.
8. A scaffolding system as claimed in Claim 6 or Claim 7 as dependent on either Claim
3 or Claim 4 wherein each C-shaped end fitting (48) has a part circular inner face,
the radius of which is equal to the outer radius of each ring (16).
9. A scaffolding system as claimed in either Claim 6 or 8 or Claim 7 when dependent on
either Claim 3 or Claim 4 wherein the ring (16) of each socket member (10) is carried
by the plates (12) at a distance from the vertical leg (2) to which these are secured
equal to the width of an arm (50) of each C-shaped end fitting (48).
10. A scaffolding system as claimed in any preceding Claim including bracing members (52)
provided at one end thereof with first attachment means (20).