GB2251451A - Scaffold fastening;wedge and pin with apertured stem - Google Patents

Description

2251451 This invention relates to scaffolding systems.

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 cord members interconnected and spaced by bracing members.

Scaffolding system have a multiplicity of uses, a particularly common one of which is to support beams, the beams being used, f or example, as a work platf orm or as part of concrete formwork. To allow such beams to be supported the vertical members of scaffolding systems are provided with support plades at their ends. A beam is connected across a number such support plates by bolting it thereto. The disadvantage of this is that the use of nuts and bolts makes the attachment of a beam to the system a fiddly and time consuming operation and the nuts and bolts are easily lost.

Another problem with known scaffolding systems arises with the type of system in which space frames are employed. The space frames are connected between adjacent vertical members by inserting pins attached to the ends of the cord members in sockets provided on the vertical members. A latch m-ember 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 position and when it is erected and in use.

In accordance with a first aspect of the invention a scaffolding system includes vertical members, at least some of which have support plates mounted at their upper and/or lower ends and means for connecting a beam to the scaffolding system by attaching it to one of the support plates, the connection means comprising a bolt so dimensioned and arranged that it can be positioned with its head so cooperating with the portion of beam as to releasably lock the two together and its stem passing through an aperture in the support plate, and a wedge member for retaining the bolt in this position, the wedge member being so dimensioned and arranged that it can be passed through an aperture in the bolt stem until it is in a position in which it abuts the support plates on either side of the bolt and forms a friction fit therewith.

The use of a.wedge member which simply has to be driven through an aperture in the bolt stem into an abutting relationship with the support plate through which the bolt is passed makes the connection of a beam to the scaffolding system a speedy and simple operation.

Very preferably the wedge is captively retained on the bolt. This may be achieved by providing at least one retaining formation on its narrow end, the retaining formation preventing the narrow end of the wedge f rom being passed through the aperture in the bolt stem. In particular the retaining formation may comprise two nibs or bosses formed on the faces of the wedge at the narrow end thereof.

The advantages of this is that instead of a nut which could be easily lost, the bolt is held in place by retaining wedge which is not separable from the bolt.

Suitably the dimensions of the parts are so arranged that the action of forcing the wedge into a friction fit with the support plate causes the bolt to pull the beam down against the support plate so that a good strong connection is produced.

The bolt head may be elongate such that its length is greater than its-width. The support plate and beam can be formed with correspondingly shaped apertures so that the bolt can passed there through and then turned to prevent its withdrawal therefrom. A suitable shape for the bolt head is that of a rhomboid.

In accordance with another aspect of the invention a scaffolding system has a plurality of vertical members provided with sockets along the lengths thereof and a plurality of space frames, the space frames being formed from two horizontal cord members interconnected and spaced by bracing members and having attachment means at either end of at least one of the cord members whereby a space frame may be connected between two adjacent vertical members, the attachment means comprising a pin for insertion into a vertical member socket, latch means carried on or in the pin and biasing means for urging the latch means towards a position in which a portion thereof latches against the socket to retain the pin therein.

The advantage of providing attachment means for the space frames which includes latch means carried on or in the pin is that the latch means can be so located that, in use, it is positioned between the vertical member and the space frame and is therefore protected.

Very 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.

Whilst the pin may be removed from the socket by pressing against the latching portion of the latch means, f or convenience, the latch means may be provided with a plate which also projects from the pin. The plate only needs to be thumb-sized and does not therefore significantly increase the amount of the latch means which is unprotected by the pin.

Suitably the biassing means comprises a spring carried in the pin.

The pin is preferably dimensioned such that it will form a close fit with the socket to thereby provide a rigid and strong connection of the space frame and vertical member.

The invention will now be further described by way of example with reference to the accompanying drawing in which:- Fig. 1 is a side view of part of a scaf f olding system in accordance with one aspect of the invention; Fig. 2 is a plan view of the scaffolding system of - 6 Fig. l.; Fig. 3 is a side view of part of the scaf folding system of Fig. l.; Fig. 4 is a side sectional view through part of a scaffolding system in accordance with another aspect of the invention, and, Fig. 5 is a view of a scaffolding system part of Fig. 4 taken in the direction of the arrow 5.

The scaffolding system comprises a plurality of vertical members 2, hereinafter referred to as legs, and space frames 4. The space frames 4, see Fig.3, comprise two horizontal cord members 6 interconnected and spaced by diagonal and vertical bracing members 8. At either end of the cord members 6 of the space frames 4, attachment means 10 are provided.

The attachment means 10 consist of a pin 12 positioned transversely to, and mounted at one end of, a cord member 4. A latch 14 is pivotally mounted at one end thereof within the pin 12. At its free end the latch 14 is formed with a hooked nib 16 which projects transversely from the main body of the latch 14, the nib 16 having a tapered surface 18. A torsion spring 20 is mounted on the pivet pin 22 by which the latch 14 is carried on the pin 12. The torsion spring 20 acts between the internal surface of the pin 12 -and the latch 14 to urge the latch to the position shown in Fig. 1 in which the hooked nib 16 extends- through a slot provided in the wall of the pin 12. In this position a thumb plate 23 also provided on the f ree end of the latch member 14 protrudes below the pin 12.

The vertical members 2 are provided with a plurality of groups of sockets 24 along their length, each group consisting of four equiangularly space sockets 24. A space f rame 4 is connected to a tubular member 2 by passing the pin 12 at one end of the spaced frame 4 into one of the sockets 24. The tapered surface 18, of the hooked nib 16 of the latch 14 as a pin 12 is pushed down into a socket 24 comes into contact with the socket wall. The socket wall rides up the tapered surface 18 and comes into contact with the extreme edge of the hooked nib 16 which causes the latch 14 to be pushed back into the pin 12 against the bias of the torsion spring 20 so allowing the pin 12 to be inserted through the socket 24. When the pin 12 has been fully inserted, the torsion spring 20 causes the latch 14 to return to the position shown in Fig. 1 in which the hooked nib 16 is located below the socket wall and thus prevents removal of the pin 12 from the socket 24.

To remove the pin 12 from a socket 24 pressure is applied to thumb plate 23 which causes the latch 14 to move back into the pin 12-against the bias of spring 20 whereafter the pin 12 can be withdrawn.

It will be noted that the pin 12 and socket 24 are both rectangular in shape and the dimensions thereof are such that when pin 12 is inserted in the socket 24 it forms a close fit therewith. This gives a strong and rigid connection between the spaced frame 4 and tubular member 2.

The majority of latch 14 is located within the pin 12 and therefore is protected from damage. The protruding portions of the latch 18 and 23 are, in use in the latching position, positioned between the tubular member 2 and a bracing member 8 of the spaced frame 4 and are therefore also protected from damage.

At its upper end the vertical member 2 carries a support plate 26. This serves to allow a beam 28 to be carried on the scaffolding structure formed by the interconnected vertical members 2 and spaced frames 4. Connection between the beam 28 and support plate 22 is via a bolt 30.

The bolt 30 has a head which is in the shape of a rhomboid. The support plate 26 and beam 28 are both formed with apertures dimensioned such that in one orientation the bolt head 32 can passed therethrough. Once the bolt head 32 has been passed through the apertures in the support plate 26 and the beam 28,turning it out of alignment with the apertures will lock it in place in these members.

As will be appreciated from Fig. 5, in the embodiment of the beam shown in the Figures, the aperture is provided by two flanges thereof which are spaced from each other. It will be appreciated that in other forms of beam the aperture could be provided by cutting into the beam.

The stem 34 of the bolt 30 is formed with an aperture dimensioned to receive a wedge member 38 therein. The dimensions of wedge member 38 are such that it can be forced into a friction fit with the aperture in the stem 34 of the bolt 30, in which position it abuts the support plate 26 on either side of the bolt 30 and forms a friction fit therewith. The wedge 38 therefore prevents the bolt 30 from being turned to bring its head 32 into alignment with the apertures in the beam 28 and support plate 26. Furthermore as the wedge 38 is forced into the aperture in the stem 34 of the bolt 30 it forces the bolt head 32 down against the beam 28 and pulls these hard against the support plate 26. A rigid and strong connection is thereby formed.

In the particular arrangement shown the portions of the support plate 26 which forms a friction fit with the - wedge 38 are two flanges 40 which extend from the main portion of the support plate 26 on either side of the aperture for the bolt 30. In this instance a washer 42 is then provided on the stem 34 of the bolt 30 which will become trapped between the main portion of the support plate 26 and the section of the wedge between the two flanges 42 to keep the connection rigid.

The wedge 38 is captively retained in the bolt 30. This is achieved by providing nibs or bosses 44 on either face of the wedge 38, the effect of which is to increase the width of the narrow end of the wedge 38 beyond that of the aperture in the stem 34 of bolt 30.

The bolt 30 and wedge 38 together provide a device which allows rapid and simple connection of a support plate to a beam. Furthermore the two cannot be separated and therefore there will less loss of equipment.

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Claims (9)

1. A scaffolding system including vertical members, at least some of which have support plates mounted at their upper and/or lower ends and means for connecting a beam to the scaffolding system by attaching it to one of the support plates, the connection means comprising a bolt so dimensioned and arranged that it can be positioned with its head so cooperating with a portion of the beam as to releasably lock the two together and its stem passing through an aperture in the support plate, and a wedge for retaining the bolt in this position, the wedge member being so dimensioned and arranged that it can be passed through an aperture in the bolt stem until it is in a position which abuts against the support plate on either side of the bolt and forms a friction fit therewith.

2. A scaffolding system as claimed in Claim 1 wherein the wedge is captively retained on the bolt.

3. A scaffolding system as claimed in Claim 2 wherein the wedge is captively retained on the bolt by providing at least one retaining formation on its narrow end, the retaining formation preventing this narrow end of the wedge from being passed through the aperture in the bolt stem.

4. A scaffolding system as claimed in Claim 3 wherein the retaining formation comprises a nib or boss formed on each f ace of the wedge at the narrow end thereof.

5. A scaffolding system as claimed in any preceding Claim wherein the dimensions of the parts are so arranged that the action of forcing the wedge into a friction fit with the support plate causes the bolt to pull the beam down against the support plate.

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6. A scaffolding system as claimed in any preceding claim wherein the bolt head is elongate.

7. - A scaffolding system as claimed in any preceding Claim wherein the support plate and beam are formed with apertures shaped to correspond to that of the bolt head.

8. A scaffolding system as claimed in any preceding claim wherein the bolt head is in the shape of a rhomboid.

9. A scaffolding system substantially as herein described and illustrated in the accompanying drawings.