[0001] This invention relates to a hooked elongate scaffolding member.
[0002] Hooked elongate scaffolding members are well known. They either have a hook at one
end or at both ends of a tube. The hooked elongate scaffolding members serve a wide
variety of purposes including acting as scaffolding and staging braces and acting
as structural support members forming part of staging platforms. The hooks of the
scaffolding members tend to get damaged if misused or abused. The scaffolding members
must then be returned to the manufacturer for repair. This is inconvenient to the
user and, since the hooks are welded to the tubes, it is relatively time consuming
and costly for the manufacturer to cut off the damaged hooks and to weld on new hooks.
[0003] It is an aim of the present invention to provide a hooked elongate scaffolding member
which can easily be repaired by the user in the event that a hook should become damaged.
[0004] Accordingly, this invention provides a hooked elongate scaffolding member comprising
a tube and a hook, the hook being releasably secured to one end of the tube by a bayonet
connection.
[0005] Preferably, the elongate scaffolding member is one in which the hook has a grooved
shank constituting one portion of the bayonet connection, and in which the interior
of the tube is provided with a pair of projections which constitute the other portion
of the bayonet connection, the projections in the tube fitting in the grooves in the
grooved shank. Obviously, if desired, the reverse arrangement may be employed in which
the interior of the tube is grooved and the shank of the hook is provided with the
pair of projections but this alternative arrangement is less easy to manufacture and
it would have a disadvantage in increasing the overall diameter of the tube, preventing
other hooked elongate scaffolding members being fitted onto that portion of the tube.
[0006] Usually, the hooked elongate scaffolding member will include releasable locking means
for releasably locking the tube and the hook together.
[0007] The locking means is advantageously a pair of screws. The screws may extend through
apertures in the tube and may locate in a threaded bush provided in a shank of the
hook. Preferably the screws will be located opposite each other.
[0008] . The elongate scaffolding member may be one in which each end of the tube is provided
with one of the hooks, each of the hooks being secured to the tube by the bayonet
connection. If only one end of the tube is provided with the hook, then the other
end of the tube may be provided with, for example, a ring coupler.
[0009] An embodiment of the invention will now be described solely by way of example and
with reference to the accompanying drawings in which:
Figure 1 is a side view of part of a hooked elongate scaffolding member in accordance
with the invention;
Figure 2 is an end view of the hook employed in Figure 1 but showing only the hook
shank part of the bayonet connection; and
Figure 3 is a side view of a threaded bush.
[0010] Referring to the drawings, there is shown a hooked elongate scaffolding member 2
comprising a tube 4 and a hook 6. The hook 6 is provided with a hooked end 8 which
is provided with a reinforcing web 10 which is designed to help prevent the hooked
end 8 being deformed. It will appreciated that if the hooked end 8 deforms inwardly
then the aperture 12 will not be sufficiently large to hook over a scaffolding tube
(not shown). The hook 6 is further provided with a shank 14 and the shank 14 is provided
with a pair of right angled grooves 16, 18 which are positioned diametrically opposite
to each other as shown. The shank 14 is tubular as can best be seen from Figure 2.
The shank 14 has a shoulder 20 against which the tube 4 abuts as it passes over the
grooves 16, 18. The tube 4 is provided with a pair of inwardly directed projections
22, 24 for engaging in the groove 16, 18 respectively. These projections 22, 24 may
be formed in the tube 4 using a hydraulic or a fly press. It will be appreciated that
the projections 22, 24 engage in the grooves 16, 18 respectively such that the projections
are first pushed in a straight line along the first part of the grooves and then either
the tube 4 or the hook 6 will be turned through 90° to complete the bayonet connection
and locate the projections 22, 24 in the ends of their grooves 16, 18. The hook 6
will then be positively but releasably secured by the bayonet connection to the tube
4.
[0011] In order to ensure that the bayonet connection does not inadvertently become released
during use, the tubular shank 14 is provided with a threaded bush 26, see Figure 3.
The bush 26 is located across the shank 14 so that two screws can then be passed through
apertures (not shown) in the tube 4 and into the threaded bush 26. The screws thus
form releasable locking means for ensuring that the bayonet connection constituted
by the grooves 16, 18 and the projections 22, 24 does not become prematurely released.
[0012] In the event that the hook 6 and particularly the hooked end 8 should become deformed,
then the user merely has to undo the screws and turn the hook 6 through 90° with respect
to the tube 4 to release the bayonet connection. The hook 6 can then be removed from
the tube 4 and a new hook 6 can be inserted in the end of the tube 4. The bayonet
connection can then be remade and the screws inserted again in the bush 26 that will
be in the new hook 6. The screw heads can be arranged to be flush in the tube 4 or
they can project from the tube 4. The hook 6 is thus very easily renewed and this
can be done by a user of the hook, for example on site. There is no need to cut off
the hook 6 as would be previously the case and to weld a new hook 6 in position. This
is particularly advantageous with the majority of scaffolding members 2 which are
made from an aluminium alloy and which requires special tungsten-inert- gas (TIG)
welding, which is costly. Alternatively, on elongate scaffolding members fitted with
a hook 6 on either end of a tube 4, should the tube 4 become deformed and the hooks
6 are servicable, then the tube 4 is very easily renewed and this can be done by the
user of the elongate scaffolding member, for example on site. Obviously, the tube
4 can also be renewed even if it only has a hook 6 on one end.
[0013] It is to be appreciated that the embodiment of the invention described above has
been given by way of example only and that modifications may be effected. Thus, for
example, a hook 6 may be provided at both ends of the tube 4. Also, if desired, other
locking means such as self-tapping screws or nuts and bolts may be employed instead
of the screws and the bush, although the screws and the bush 26 are preferred since
they make a flush fitting connection.
1. A hooked elongate scaffolding member comprising a tube and a hook, the hook being
releasably secured to one end of the tube by a bayonet connection.
2. A hooked elongate scaffolding member according to claim 1 in which the hook has
a grooved shank constituting one portion of the bayonet connection, and in which the
interior of the tube is provided with a pair of projections which constitute the other
portion of the bayonet connection, the projections in the tube fitting in the grooves
in the grooved shank.
3. A hooked elongate scaffolding member according to claim 1 or claim 2 and including
releasable locking means for releasably locking the tube and the hook together.
4. A hooked elongate scaffolding member according to claim 3 in which the locking
means is a pair of screws.
5. A hooked elongate scaffolding member according to claim 4 in which the screws extend
through apertures in the tube and locate in a threaded bush provided in a shank of
the hook.
6. A hooked elongate scaffolding member according to claim 5 in which the screws are
located opposite each other.
7. A hooked elongate scaffolding member according to any one of the preceding claims
in which each end of the tube is provided with one of the hooks, each of the hooks
being secured to the tube by the bayonet connection.
8. A hooked elongate scaffolding member according to any one of claims 1 to 6 in which
only one end of the tube is provided with the hook, and in which the other end of
the tube is provided with a ring coupler.