GB2058189A

GB2058189A - Releasable Fastenings

Info

Publication number: GB2058189A
Application number: GB7928401A
Authority: GB
Original assignee: GKN Mills Building Services Ltd
Current assignee: RMD Kwikform Ltd
Priority date: 1979-08-15
Filing date: 1979-08-15
Publication date: 1981-04-08
Also published as: GB2058189B

Abstract

Horizontal decking 10 for use in builder's scaffolding is locked onto two spaced horizontal cross members 42 between which it is supported. The locking connection comprises a tongue 18 adapted to rest on a scaffold cross member 42 and a restraining arm 46 pivotable under gravity from a retracted position to an extended and locked position wherein the tongue extends below a lower surface of the cross member upon which the tongue is resting whereby the decking is restrained against vertical movement relative to the cross member. The cross members may be square, as shown, or round. <IMAGE>

Description

SPECIFICATION Frame Connector This invention relates to a connection between frame members and particularly to a locking connection between a decking member and other elements of a scaffold structure.

Various forms of quick release connector are known in the scaffolding industry. For example one such connector comprises a hook-like element secured to one end of a tubular scaffold member for securing such member perpendicuiarly to a further tubular scaffold member. The hook element includes a snap action looking element actuabie into its locking position after the hook is engaged with the scaffold member whereby the two members are positively securable together.

Also in scaffolding structure it is known to provide working platforms or decks to span the distance between spaced horizontal scaffold members. Such decking is known to be provided with hook-like elements at each end for engagement with the scaffold members between which it is supported but such hooks do not lock the decking in position.

It is a broad object of the present invention to provide a new or improved form of connection between adjacent frame members. A further object is to provide such a connection for scaffold members and in particular a connection for securing decking structure in a scaffold assembly.

In accordance with one aspect of the invention there is provided a connector for joining together adjacent frame members, the connector being fixedly secured to a first one of said frame members and comprising a tongue adapted to rest on an upper surface of a second one of said frame members thereby to support said first frame member on said second frame member, and a restraining arm movable between a retracted position away from said tongue and an extended position towards said tongue in which it extends below a lower surface of said second frame member; said restraining arm being lockable in its extended position whereby, when said arm is extended below the lower surface of the second frame member and said tongue is resting on the upper surface thereof, said first frame member is restrained against vertical movement relative to second frame member.

Also in accordance with the invention there is provided a scaffold assembly comprising a first horizontal member having a connector fixedly secured to one end thereof and a second horizontal member disposed perpendicular to said first member, said connector comprising a tongue resting on an upper surface of said second member thereby to support said first member thereon, and a restraining arm movable between a retracted position away from said tongue and an extended position towards said tongue in which it extends below a lower surface of said second member; said restraining arm being lockable in its extended position whereby said first member is restrained against vertical movement relative to said second member.

Conveniently the first horizontal member comprises part of a horizontal decking structure wherein said structure includes two said first horizontal members in spaced parallel relation to one another extending the length of the decking with a said connector being secured to each end of each said member whereby the decking may be supported between two spaced said second horizontal members. The restraining arm on the connector is conveniently pivotally mounted thereon so as to be movable under gravity from its retracted position to its extended and locked position; the restraining arm conveniently being so arranged that it is so movable to its extended and locked position when the tongue is engaged with a said second horizontal member.

Other features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein: Figure 1 is an underneath perspective view of scaffold decking having connectors thereon in accordance with the invention; Figure 2 is a detail side elevation of a connector engaged with an adjacent square section horizontal scaffold member; Figure 3 is a perspective view of an alternative form of connector similar to that shown in Figure 2; Figure 4 is a detail side elevation of a further alternative form of connector for use with round section horizontal scaffold members, and Figure 5 is an end elevation of the connector of Figure 4.

In the following description and accompanying drawings the connector in accordance with the invention is described and illustrated for use in securing horizontal decking between spaced horizontal scaffold members in a scaffold structure. It should be appreciated however that the connector may be used in other applications wherein adjacent frame members are required to be connected together.

Referring to Figure 1 of the drawings there is illustrated a scaffold decking structure comprising a flat wooden board 10 of dimensions of the order of 100 cm. by 50 cm. Extending along the under surface of the deck, adjacent each side edge thereof, is an extruded aluminium box section member 12 having typical internal dimensions of 2.5 cm. by 5 cm. As illustrated the side walls of the section extend below the hollow interior to give added stiffness. Adjacent each end of the decking there is provided a transverse bracing member 14 which may also conveniently comprise an extruded aluminium section.

At each end of each of the two side members 1 2 there is secured a connector 1 6 in accordance with the invention; one such connector being shown in more detail in Figure 2 of the drawings.

The connector 16 is formed as an aluminium extrusion and comprises an upper forwardly extending tongue 18, a centre body portion 20, and a rear extension 22 for engagement within the hollow box section member 12. Said rear extension comprises a pair of spaced arms 24, externally ribbed to maximise frictional engagement within the box member 12, and an abutment shoulder 26 provided at the rear edge of the body portion 20 to locate the connector relative to the member 12. The connector is welded to the member 12 along the vertical sides of the member at the end thereof. The body portion 20 is formed with a four sided aperture therein bounded by a lower inclined face 28, a rear inclined face 30 and upper and front faces 32-34 which merge together at a radiused front and upper corner 36.The outer front surface of the body portion 20 comprises an abutment face 38 perpendicular to the lower face 40 of the extending tongue 18 whereby the connector may rest snugly on a square section horizontal scaffold member 42 as shown in chain dotted outline in Figure 2. The upper surface of the extending tongue 1 8 is raised above the upper surface of the body portion 20 to provide a shoulder 44 so that the deck board 10 may project forwardly over the body portion 20 of the connector to be substantially flush with the upper surface of the extending tongue 1 8 and abut against the shoulder 44.

The connector further includes a restraining arm comprising a sheet metal member having two laterally spaced extending fingers 46 connected by a generally U-shaped saddle portion having sides 48 extending perpendicularly from said fingers at their rearward ends and a bridge portion 50 perpendicular to the sides and inclined thereto at an angle corresponding to the angle of inclination of the lower inclined face 28 of the connector body portion 20. The rear inclined face 30 of the body portion is extruded with a slot 52 so that the sheet metal restraining arm may be inserted therethrough into the aperture in the body portion.

The lower inclined face 28 of the body portion 20 further includes, at its lower most rearward extent, a recess 54 extending the width of the connector and rearward of the rear inclined face 30. Also provided in the lower inclined face 28 adjacent its forward end is a depression 56 extending the full width of the face 28.

From the chain dot outline of Figure 2 it will be seen that the restraining arm is effectively pivotally mounted on the connector with the upper forward corner of the bridge 50 being locatable in the recess 56 so as to locate the restraining arm in a "cocked" position. Dislocation of the restraining arm from the "cocked" position permits it to fall under gravity with said corner of the bridge 50 riding forwardly up the lower inclined face 28 of the body portion 20 until the remainder of the bridge contacts the face 28 at which time the restraining arm will slide rearwardly, under gravity, into the rearward recess 54 locking the restraining arm in the position shown in full line in Figure 2.

The restraining arm is thus movable from a retracted position, in which the fingers 46 are rearward of the line of the front abutment face 38 of the body portion 20, to an extended and locked position in which the fingers 46 are parallel to the upper tongue 1 8. In use therefore the restraining arm is first of all placed in its "cocked" position and the tongue 1 8 of the or each connector is placed onto the upper surface of a scaffold member 42. In the embodiments illustrated in Figures 1 and 2 the restraining arms on all four connectors will be placed in their "cocked" positions and the decking will be lowered into position between two spaced parallel horizontal scaffold members.Dislocation of each restraining arm from its "cocked" position will thus permit each arm to fall under gravity to the locked and extended position shown in full line in Figure 2 thereby restraining the decking against vertical movement relative to the scaffold members upon which it is supported.

In Figure 3 of the drawings a connector similar to that shown in Figure 2 is illustrated except that the Figure 3 embodiment is intended for use with a square section box member of typical internal dimensions 5 cms. by 5 cms. Basically the construction of the connector shown in Figure 3 is the same as that described with reference to Figure 2 and is intended to be secured by welding in the end of a box section scaffold member of 5 cms. by 5 cms. internal dimensions. The connector is again formed as an aluminium extrusion having a tongue 18, body portion 20 and rearward extension 22 as described and illustrated with reference to Figure 2 wherein like reference numerals refer to like parts. However the additional width of the connector of Figure 3 enables a different form of restraining arm to be utilised.In this construction, a slot 58 is formed in the connector extending through part of the tongue 1 8 through the front face 38 of the body portion 20 and also through the lower inclined face 28. The restraining arm comprises a rectangular plate 60 having a single cranked finger 62 secured thereto which extends through the slot 52 in the connector. As is shown by the chain dot and full line outlines of Figure 3 the restraining arm is again movable pivotally under gravity from a retracted or "cocked" position to an extended and locked position wherein the finger 62 is locatable below the lower surface of a square section horizontal scaffold member upon which the connector is supported; the connector, and the member to which it is attached, then being restrained against vertical movement relative to the scaffold member.

Figures 4 and 5 of the drawings, wherein like reference numerals refer to like parts hereinbefore described, illustrate a further embodiment of connector in accordance with the invention intended for use in securing a connector, and a member 12 to which it is attached to a round cross section horizontal scaffold member 42. In this construction the connector is again formed as an aluminium extrusion having a curved or hooklike tongue 18, a body portion 20 and a rearward extension 22 for engagement within, and welding to, the end of a square section member 12.In this construction, as used for supporting scaffold decking 10, it will be noted that there is provided a projection 64 at the rearward upper end of the hook 18 substantially in alignment with the upper surface of the body portion 20 whereby the decking board 10 may extend forwardly over the full length of the body portion 20 and be supported on said projection 64. The body portion 20 of the connector is formed with an aperture having a vertical rear face 66 and an inclined upper surface 68 merging into the rear face 66 through the provision of a recess 70. The aperture further includes an inclined front face 72 and a lower face comprising two mutually upwardly convergent surfaces 74-76; a projection 78 extending laterally across the full width of the body portion aperture at the uppermost edge of the rearward inclined lower face 74.

The restraining arm comprises a pair of hook shaped fingers 80 conveniently formed of metal rod. The fingers extend rearwardly from the hook portions thereof through an approximate 450 bend and are joined together by a pair of transverse rods welded thereto. Said transverse rods comprise a rearmost rod 82 adjacent the rear ends of the fingers 80 and an intermediate rod 84 at the rearward termination of the hook portions.

As is best shown in Figure 4 in chain dot outline, the restraining arm is thus locatable in a retracted and "cocked" position in which the rearmost rod 82 is engaged within the recess 70 at the rear upper position of the body portion aperture. Dislocation of the restraining arm from its recess 70 enables it to pivot under gravity to the position shown in full line in Figure 4 wherein the rearmost rod 82 is engaged behind the projection 78 thereby locking the restraining arm in position with the hook portion 80 thereof located below the round section scaffold member 42. In the extended and locked position of the restraining arm the member 12 to which the connector is fitted, i.e. the scaffold decking, is restrained against vertical movement relative to the round sectin scaffold member.

Claims

1. A connector for joining together adjacent frame members, the connector being fixedly secured to a first one of said frame members and comprising a tongue adapted to rest on an upper surface of a second one of said frame members thereby to support said first frame member on said second frame member, and a restaining arm movable between retracted position away from said tongue and an extended position towards said tongue in which it extends below a lower surface of said second frame member; said restraining arm being lockable in its extended position whereby, when said arm is extended - below the lower surface of the second frame member and said tongue is resting on the upper surface thereof, said first frame member is restrained against vertical movement relative to said second frame member.

2. A connector as claimed in Claim 1 for use in joining together adjacent horizontal scaffold members.

3. A connector as claimed in either one of Claims 1 or 2 wherein the restraining arm is pivotally mounted thereon and is movable under gravity from its retracted position to its extended and locked position.

4. A connector as claimed in any one of the preceding claims wherein the restraining arm is movable from its retracted position to its extended and locked position when the tongue is engaged with the second frame member.

5. A connector as claimed in any one of the preceding claims fixedly secured to an end of said first frame member, said first frame member comprising part of a horizontally disposable decking structure.

6. A scaffold assembly comprising a first horizontal member having a connector fixedly secured to one end thereof and a second horizontal member disposed perpendicular to said first member, said connector comprising a tongue resting on an upper surface of said second member thereby to support said first member thereon, and a restraining arm movable between a retracted position towards said tongue in which it extends below a lower surface of said second member; said restraining arm being lockable in its extended position whereby said first member is restained against vertical movement relative to said second member.

7. An assembly as claimed in Claim 6 wherein said first horizontal member comprises part of a horizontal decking structure.

8. An assembly as claimed in Claim 7 wherein said decking structure includes two said first horizontal members in spaced parallel relation with one another extending the length of the decking, a said connector being secured to at least one end of each said member whereby the decking may be supported between two spaced said second horizontal members.

9. An assembly as claimed in any one of Claims 6 to 8 wherein the restraining arm is pivotally mounted on the connector and is movable under gravity from its retracted position to its extended and locked position when the tongue is engaged with said second member.