GB2291457A - Scaffolding - Google Patents

Description

2291457 SCAFFOLDING The present invention relates to a telescopic brace

and to a scaffolding frame unit including a telescopic brace.

In many fields, structural units are used that need to be stabilised. For example, in the construction, repair and maintenance fields, light-weight scaffolding frame units are assembled to form access towers. It is important that these access towers are sufficiently stable and safe.

According to a first aspect of the present invention there is provided a telescopic brace for scaffolding frames comprising an inner tube, an outer tube, means at one end adapted to pivotally connect the brace to a frame, and a coupling at the other end for releasably coupling a frame, wherein the tubes are releasably lockable against telescopic movement when the brace is in an extended position.

Preferably, the tubes are releasably lockable against telescopic movement by rotation of one tube relative to the other.

According to a second aspect of the present invention there is provided a scaffolding frame unit adapted to fit together with further similar units and having a telescopic brace pivotally connected at one end to the frame unit, wherein the telescopic brace has a coupling at its free end adapted for releasably coupling the frame unit or a further similar frame unit.

Embodiments of the present invention, will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a front view of an access tower assembled from scaffolding frame units and having two telescopic braces; Figure 2 shows a cross-sectional view of an 2 - unextended telescopic brace; Figure 3 shows a cross-sectional view of an extended telescopic brace; and Figure 4 shows an enlarged perspective view of a part of the telescopic brace.

Referring to Figure 1, an access tower is assembled from a plurality of scaffolding frame units 2.

A scaffolding frame unit 2 comprises a generally rectangular frame 4 formed of two parallel vertical tubular side pieces 6 and two parallel horizontal crosspieces 8 welded between the side pieces within the length of the side pieces. As a result, the side pieces 6 extend beyond the internal corners of the rectangular frame to provide external corners 10. In each external corner, a mounting point is fixed to the frame.

Each mounting point comprises a rod or pin 14 mounted between opposing side supports 16 (only one side support of each mounting point is shown in Figure 1).

The access tower is assembled by connecting a scaffolding frame unit perpendicularly to adjacent scaffolding frame units using internal spigot joints. For example, Figure 1 shows, face on, a scaffolding frame unit A which is connected to an identical scaffolding frame unit B; unit B being shown edge on since it lies at right angles to unit A.

As shown in Figure 1, each scaffolding frame unit also comprises a vertical cross-bar 18.

The access tower is stabilised using telescopic braces. A telescopic brace 20 is pivotally connected at one end to a mounting point 22 fixed to the scaffolding frame unit located above unit B. The brace is extended to releasably couple, at its other end, a mounting point 24 fixed to unit A and located diagonally opposite mounting point 22.

Unit A also has a telescopic brace 26 pivotally v- connected at one end to a mounting point 28 fixed to unit A. This brace is shown in Figure 1 in its unextended position in which it is releasably coupled, at its other end, to a mounting point 30, also fixed to unit A. The telescopic brace is thus stowed for storage and transport.

In use, the telescopic brace is extended to releasably couple a mounting point 32 located diagonally opposite mounting point 30, in the same way as telescopic brace 20.

Telescopic braces are similarly provided on other faces of the access tower. For example, unit B has a telescopic brace releasably coupled to a mounting point located in its upper right-hand corner, and another telescopic brace pivotally connected to a mounting point located in its lower left-hand corner (these braces are not shown in the figures).

Referring to Figures 2 and 3, each telescopic brace comprises an inner tube 34 and an outer tube 36.

Attached to the free end of outer tube 36 is a coupling 38 which latches onto a pin 14 of a mounting point to couple the telescopic brace to a frame unit. In Figures 2 and 3, coupling 38 is shown for simplicity as a basic hook; in practice, the coupling will be a releasable coupling incorporating a latch.

The free end of inner tube 34 is provided with an aperture 40 through which a pin 14 is inserted to pivotally connect the telescopic brace to a frame unit.

The other end of the inner tube, which is located inside the outer tube, has a stopper 46 fixed thereto. The inner tube also has an elongate slot 42 extending along its length.

Stopper 46, as shown more clearly in Figure 4, comprises an outer rim 52, an inner rim 54, and a cylindrical groove 44 which separates the inner and outer rims. The inner rim 54 is dimensioned to fit within inner tube 34 and is partly cut away to form a flat portion 50.

- 4 The outer tube carries a radially-extending pin 48. This pin is welded to the outer tube once the inner tube has been inserted therein. The pin is restricted for longitudinal movement in elongate slot 42: this controls the telescopic movement of the brace.

The outer tube can only rotate relative to the inner tube when the telescopic brace is in the extended position shown in Figure 3. This rotation is then permitted by pin 48 entering circumferential groove 44 from elongate slot 42, having passed over flat surface 50. Rotation of the outer tube relative to the inner tube thus locks the brace against telescopic movement. In Figure 3, the outer tube has been rotated 1800 relative to the inner tube.

Further rotation of the outer tube relative to the inner tube returns the pin to its original position so that the pin can return over flat surface 50 to the elongate slot, thereby allowing further telescopic movement of the brace so that it can return to the unextended position shown in Figure 2.

The outer rim 52 of stopper 46 prevents the pin from progressing any further than circumferential groove 44. Thus, when the brace is extended such that the pin abuts against outer rim 52, a user knows that rotation of the outer tube will releasably lock the brace against telescopic movement.

In another embodiment, the inner tube is provided with more than one circumferential groove such that the brace can be releasably locked against telescopic movement at different extensions.

Further, the circumferential groove(s) may be formed in the inner tube itself rather than being provided in a separate element such as the stopper 46.

The lockable feature of the brace provides diagonal rigidity for access towers.

In one example, the inner tube is 800 mm long with a diameter of 38 mm. The elongate slot 42 formed in the inner tube is 370 mm long and 14 mm wide. The stopper 46 fixed to one end of the inner tube is 51 mm in length and 41 mm in diameter.

The outer tube is 1700 mm long with a diameter of 48 mm. It has an aperture, located 1300 mm from the end of the outer tube to which the coupling 38 is fixed, into which the pin 48 is inserted. The pin is 25 mm long and has a diameter of 13 mm.

In this example, the brace is able to extend to a length of 2218 mm.

The inner tube may be a log alloy tube and the outer tube may be a 17g alloy tube; suitable alloy tubes being sold by British Alcan.

Claims (4)

1. A telescopic brace for scaffolding frames comprising an inner tube, an outer tube, means at one end adapted to pivotally connect the brace to a frame, and a coupling at the other end for releasably coupling a frame, wherein the tubes are releasably lockable against telescopic movement when the brace is in an extended position.

2. A telescopic brace as claimed in Claim 1, wherein the tubes are releasably lockable against telescopic movement by rotation of one tube relative to the other.

3. A telescopic brace as claimed in claim 1 or Claim 2, wherein the inner tube has an elongate slot extending along its length and connected to a circumferential groove; and wherein the outer tube carries a pin restricted for longitudinal movement in the elongate slot; the tubes being releasably lockable against telescopic movement by rotation of the pin in the circumferential groove.

4. A scaffolding frame unit substantially as I v v v - 4 0 0k hereinbefore described with reference to the accompanying drawings.

4. A scaffolding frame unit adapted to fit together with further similar units and having a telescopic brace pivotally connected at one end to the frame unit, wherein the telescopic brace has a coupling at its free end adapted for releasably coupling the frame unit or a further similar frame unit.

5. A scaffolding frame unit as claimed in claim 4, further comprising first and second mounting points, the telescopic brace being pivotally connected to the first mounting point, and the coupling being adapted for releasably coupling either the second mounting point on the frame unit or a second mounting point on a further similar frame unit.

6. A scaffolding frame unit as claimed in Claim 5, comprising a generally rectangular frame formed of two 1 parallel tubular side pieces and two parallel cross-pieces welded between the side pieces within the length of the side pieces such that the side pieces extend beyond the internal corners of the rectangular frame to provide external corners, four mounting points fixed to the frame, one in each of the external corners; the telescopic brace being pivotally connected at one end to one of the mounting points and the coupling being adapted for releasably coupling another mounting point on the frame unit or on another similar frame unit.

7. A scaffolding frame unit as claimed in any one of Claims 4 to 6, wherein the telescopic brace is as claimed in any one of Claims 1, 2 or 3.

8. A telescopic brace substantially as hereinbefore described with reference to the accompanying drawings.

9. A scaffolding frame unit substantially as hereinbefore described with reference to the accompanying drawings.

W c a Amendments to the claims have been filed as follows CLAIMS 1. A scaffolding frame unit adapted to fit together with further similar units comprising a frame, first and second mounting points fixed to the frame, and a telescopic brace pivotally connected at one end to the first mounting point; wherein the telescopic brace has a coupling at its free end adapted for releasably coupling to either the second mounting point of the frame unit or a second mounting point of a further similar frame unit; and wherein the brace comprises an inner tube and an outer tube which are releasably lockable against telescopic movement by rotation of one tube relative to the other when the brace is in an extended position.

2. A telescopic brace as claimed in claim 1, wherein the inner tube has an elongate slot extending along its length and connected to a circumferential groove; and wherein the outer tube carries a pin restricted for longitudinal movement in the elongate slot; the tubes being releasably lockable against telescopic movement by rotation of the pin in the circumferential groove.

3. A scaffolding frame unit as claimed in Claim 1, comprising a generally rectangular frame formed of two parallel tubular side pieces and two parallel cross-pieces welded between the side pieces within the length of the side pieces such that the side pieces extend beyond the internal corners of the rectangular frame to provide external corners, four mounting points fixed to the frame, one in each of the external corners; the telescopic brace being pivotally connected at one end to one of the mounting points and the coupling being adapted for releasably coupling to another mounting point of the frame unit when the brace is retracted and to a mounting point of another similar frame unit when the brace is extended.