GB2156028A

GB2156028A - Scaffolding cross members

Info

Publication number: GB2156028A
Application number: GB08404552A
Authority: GB
Inventors: Michael Richard Rushmer; George Bernard Arthur Young
Original assignee: LEADA Ltd
Current assignee: LEADA Ltd
Priority date: 1984-02-21
Filing date: 1984-02-21
Publication date: 1985-10-02
Also published as: GB8404552D0

Abstract

A scaffold cross member (10) has connecting means (14, 16) secured at least at one end thereof, the connecting means comprising a dependant spigot (14) and a wedge member (16) captively mounted thereon. The wedge member (16) has a slot (24) including an offset "kink" portion (26) which is engaged by a pin member (22), the kink portion (26) acting to wedge simply and efficiently against the pin member (22) and hold the wedge member (16) in its withdrawn 'uppermost' position. <IMAGE>

Description

SPECIFICATION Improvements in and relating to scaffolding cross members This invention relates to builder's scaffolding and particularly to cross members such as ledger and transom elements.

Cross members are used to connect a plurality of upright members together so as to form a stable and rigid building scaffold. The cross members are detachably connected to sockets on the upright members by connecting means provided at one or both ends thereof.

A scaffold cross member in accordance with the invention has connecting means secured at least at one end thereof, the connecting means comprising a dependent spigot and a wedge member captively mounted on the cross member or spigot, the wedge member having a slot including an offset portion which is engaged by a pin or the like, the offset portion acting to wedge against the pin or the like to hold the wedge in a withdrawn 'uppermost' position.

Such an arrangement is simple in design and construction. Furthermore, the arrangement is extremely simply to use as only a single movement of the wedge is required either to secure the cross member to or remove it from, the upright members.

Preferably the wedge is captively mounted on the spigot by means of a pin member on the spigot engaging the slot of the wedge.

The arrangement of the spigot and wedge is preferably such that the spigot is fixed to the outer end of the cross member and the wedge outwardly of the spigot. In use the wedge and spigot are both placed in the socket of an upright member and when the wedge is in its operating and 'lowermost' position the outer face of the wedge engages the upright member while the inner face of the spigot engages the socket. The inner face of the wedge and outer face of the spigot may both be inclined but in opposite senses to each other.

The spigot may be provided with a groove in which is retained the wedge. This is advantageous in that firstly sideways movement of the wedge is controlled and secondly the width of the spigot is widened overcoming any weak points at the neck or elsewhere of the spigot.

The spigot is preferably provided with a ledge or ridge portion on the side, whereby when the spigot and wedge are placed in the socket of an upright member, the ledge rests on the top of the socket giving stability to the arrangement.

In accordance with another aspect of the invention, a scaffold element comprises a cross member and connecting means in the form of a dependent spigot and wedge member, the connecting means including a member which extends within the cross member and having a plurality of depressions into which the cross member is deformed in order to secure the connecting means to the crossmember.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side view of a scaffold element in accordance with the invention when in its operating and "lowermost" position, Figure 2 is a side view of the scaffold element of Fig. 1 when in its withdrawn and "uppermost" position, and Figure 3 is a plan view of a portion of the scaffold element of Fig. 1.

In the drawings, a scaffold element 10 comprises a cross-member 12, a dependent spigot 14 attached to the outer end of the member 1 2 and a wedge member 1 6 positioned outwardly of the spigot 1 4.

The spigot 14 and wedge 1 6 are shown placed within a socket 1 8 of an upright member 20. In Fig. 1 the connecting means in the form of the spigot and members are securely positioned within the socket 18, the outer face 1 6a of the wedge flush and adjacent the upright member 20 and the inner face 14a of the spigot flush and adjacent the outer end of the socket 18. In Fig. 2, the connecting means are shown loosely positioned within the socket 18.

The inner face 1 6b of the wedge and outer face 1 4b of the spigot meanwhile, are both inclined at the same angle but in opposite senses to each other, so as to form the wedging surfaces and thereby the wedging action for the connecting means.

The wedge 1 6 is held captive by the spigot 1 4 by means of a pin member 22 which engages a slot 24 in the wedge. The lower end 26 of this slot 24 is offset to the rest of the length of the slot such that when the wedge 1 6 is raised to its withdrawn and uppermost ' position (see Fig. 2), the slight 'kink' 26 in the slot forces the wedge to be wedged against the spigot 14 and retained in the withdrawn position. The wedge 1 6 will remain there until it is knocked back into its "lowermost ' position (see Fig. 1) by means of for example a hammer blow.

It will be appreciated that the slight kink 26 in the slot need only be offset to the rest of the slot 24 by a few degrees, preferably between 2 to 15N Furthermore the kink 26 extends only over between a tenth and a quarter of the whole length of the slot.

The spigot 1 4 is substantially V-shaped and provided with a groove 28 (see Fig. 3) in which the wedge 1 6 is retained, whereby sideways movement of the wedge is controlled. The sides 29 of the spigot which define the groove 28 also act to widen the width of the spigot 1 4 and increase the strength and rigidity of the spigot 1 4. For instance, it will be noted that the width of the neck (see 30 in Fig. 2) is small and would have provided a weak point in the arrangement should the spigot 14 have not been widened and provided with a groove 28 for wedge retension.

The sides 29 of the spigot 14 are also provided with a ridge or ledge 32 which, when the spigot and wedge are placed in the socket 18, rest on the top of the socket 1 8 and give extra stability to the whole arrangement.

In the drawings, the spigot 14 is shown having an inner member 34 which extends within the cross member 1 2. The member 34 comprises two end plates 36 and 38 (one of which is integral with the spigot 14) and a central horizontally disposed flanged portion 40 therebetween. The portion 40 is relatively thick and has four depressions 42 (two on each side) therein, into which the cross member 1 2 is deformed (see 44) in order to secure the connecting means to the cross member.

Advantageously this arrangement provides for secure and rigid attachment of the spigot to the cross-member without the necessity for welding or the like which may be liable to breakage when stressed. This is because the provision of the relatively long inner member 34 results in the stresses and loads acting on the scaffold being dispersed over the whole length of the member 34 as opposed to welding or the like where the stresses and loads will be concentrated on one point.

The plates 36 and 38 of the member 34 are also provided with four series of external grooves (46, 48, 50) symmetrical about the longitudinal axis of the member 34, which are used to accommodate the weld ridge found on the inside of the tubuler cross-member 12, prior to the member 1 2 being deformed (see 44) into the depressions 42.

Preferably the wedge 1 6 is cast or forged of high quality steel while the spigot 14 and inner member 34 are made from malleable cast iron, and the cross member 1 2 is made from mild steel tube.

Claims

1. A scaffold cross member having connecting means secured at least at one end thereof, the connecting means comprising a dependent spigot and a wedge member captively mounted on the cross member or spigot, the wedge member having a slot including an offset portion which is engaged by a pin or the like, the offset portion acting to wedge against the pin or the like to hold the wedge in a withdrawn 'uppermost' position.

2. A scaffold cross member as claimed in Claim 1 wherein the wedge member is captively mounted on the spigot by means of a pin member on the spigot engaging the slot of the wedge.

3. A scaffold cross member as claimed in either Claim 1 or 2 wherein the spigot is fixed to the outer end of the cross member and the wedge outwardly of the spigot

4. A scaffold cross member as claimed in any preceding claim wherein the inner face of the wedge and outer face of the spigot are both inclined but in opposite senses to each other.

5. A scaffold cross member as claimed in any preceding claim wherein the spigot is provided with a groove in which is retained the wedge.

6. A scaffold cross member as claimed in any preceding claim wherein the spigot is provided with a ledge or ridge portion on the exterior side thereof.

7. A scaffold cross member as claimed in any preceding claim wherein the offset portion of the slot is in the form of a slight kink.

8. A scaffold cross member as claimed in any preceding claim wherein the offset portion of the slot is offset to rest of the slot between 2 to 15".

9. A scaffold cross member as claimed in any preceding claim wherein the offset portion of the slot extends only over between a tenth and a quarter of the whole length of the slot.

10. A scaffold cross member as claimed in any preceding claim wherein the connecting means includes a member which extends within the cross member and having a plurality of depressions into which the cross member is deformed in order to secure the connecting means to the cross member.

11. A scaffold cross member as claimed in Claim 10 wherein the member which extends within the cross member is formed with at least one groove to accommodate the weld ridge found on the inside of the cross member.

1 2. A scaffold element comprising a cross member and connecting means in the form of a dependent spigot and wedge member, the connecting means including a member which extends within the cross member and having a plurality of depressions into which the cross member is deformed in order to secure the connecting means to the cross member.

1 3. A scaffold cross member substantially as herein described with reference to Figs. 1 to 3 of the accompanying drawings.