GB2410288A - Pivoting scaffold guard rail device - Google Patents

Abstract

A device comprises a post 32, clamps 44 which allow rails to be attached to the post, a pivot arrangement 64 having a means for securing the arrangement to a scaffold member 80, preferably in the form of a collar 76 with locking bolt 88 and a pivot axis and means for holding the post in place. In use, the pivot axis is located above the point at which the post is secured to a scaffold ledger. Preferably the post is held in position by hooks 42 which locate over scaffold rails. In order to move the guard rail a handle 38, is used to lift the post so that a bolt 72, Figure 2 which forms the pivot axis moves in a slot 74, figure 2, the post is then able to pivot.

Description

Scaffolding Construction The present invention relates to scaffolding

construction.

Scaffolding is commonly constructed for temporary access above ground level for building construction and maintenance, and many other purposes. Modern safety practices require safety provisions for personnel on the scaffolding, above ground level. For example, guard rails are used to prevent falls. Altematively, attachment points can be provided for harnesses but these are generally less preferred by users, because they may hinder free movement around the scaffolding.

Good operating practices also require equivalent safety provision to be effective while personnel are involved in the construction and dismantling of the scaffolding.

The present invention provides a device for use in the construction of scaffolding, comprising: a post member; at least one releasable guard rail clamp arrangement operable to attach a guard rail to the post member; a pivot arrangement operable to provide pivotal attachment between the post member and a scaffolding member, whereby a guard rail attached to the post member may be raised and lowered by pivoting the post member; a holding arrangement operable to releasably hold the post member against pivoting, whereby to hold a guard rail in a raised position; wherein the pivot arrangement comprises an attachment arrangement for attachment to a scaffolding member, and defines a pivot axis for the post member, the pivot axis being, in use, spaced above the attachment ;- arrangement, whereby the vertical length of the post above the scaffolding member, when the post member is in the raised position, is greater than the length of the post member above the pivot axis.

Preferably, the attachment arrangement attaches, in use, to a scaffolding ledger. The pivot arrangement may comprise an intermediate member which provides the attachment arrangement and a pivot axis defining arrangement at respective positions along its length. The attachment arrangement may include a collar locatable around a scaffolding member, and a threaded arrangement operable to tighten against a member in the collar, to secure the attachment member to the member. The collar may be shaped to fit over a scaffolding member, in use, whereby to support at least some of the weight of the device on the member prior to the threaded arrangement being tightened. The threaded arrangement may include an elongate threaded member rotatably mounted in the pivot arrangement to be advanced, by rotation, to grip a scaffolding member received in the collar. The elongate threaded member may have an axis which does not intersect the member axis defined by the collar, whereby the threaded member obliquely engages a member received in the collar, to resist rotation of the collar relative to the member.

The pivot axis defining arrangement may include a pivot pin projecting from the intermediate member and through the post member. The pivot axis defining arrangement preferably comprises a pair of arms which embrace the post member, the pivot pin extending between the arms. The pivot pin may be located in a slot formed in the post member, whereby the post member is movable in a longitudinal direction relative to the pivot pin.

The holding arrangement may act between the post member and a fixed member located below the pivot member. The fixed member is preferably a guard rail. The holding arrangement may comprise a hooked I; . . ' . "e al; member. The hooked member may be mounted on the post member and be movable transversely of the pivot axis for engagement and disengagement with the fixed member.

The guard rail clamp arrangement preferably includes a clamp arm mounted on the post member and movable to clamp a guard rail against the post member, the clamp arm being also mounted to pivot away from the guard rail upon its release.

The clamp arrangement may comprise a pivot pin around which the clamp arm may pivot. The clamp arrangement may comprise engaging means operable to engage the post member as the clamp arm clamps a guard rail, to resist pivoting. The engaging means may comprise fingers which embrace the post member to resist pivoting, and which release the post member as the clamp arm releases the guard rail.

The clamp arm may be mounted by means of an elongate threaded member through the clamp amm and the post member, the elongate threaded member cooperating with a further threaded member to create clamping movement, and cooperating with the clamp arm to provide pivotal movement of the clamp arm around the threaded member.

In another aspect, the invention provides a method of installing guard rails for scaffolding which has at least one level above which a scaffolding member is installed for supporting a higher level, in which at least two devices as defined above are pivotally attached to the member by means of the respective pivot arrangements, the post members are pivoted over to lie across the said higher level, at least one guard rail is attached to the post members while they are lying across the said higher level, the post members are brought to their substantially upright positions by means of the pivot arrangements thereby moving the guard rail to a temporary position, guarding . e.. ë.e

the said higher level, and the holding arrangements are engaged to hold the post members in the raised positions.

An embodiment of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram of scaffolding with which a device according to the present invention may be used; Fig. 2 is an exploded view of a device in accordance with the present invention; Figs. 3A to C are respectively side elevation, rear elevation and plan views of a guard rail clamp of the device of Fig. 2; Fig. 4 is a side elevation of a pivot arrangement of the device of Fig. 2; Fig. 5 is a partial elevation of the device in use; and the remaining figures schematically illustrate a method of installing guard rails, using the device of Fig. 2.

Scaffolding Fig. 1 illustrates a conventional scaffolding arrangement at an early stage in its construction, allowing the principal components to be identified.

Specifically, the lowest level (usually known as a "lift") has been fully completed and the scaffolding is ready for construction of a second lift at a higher level.

. . . The scaffolding 10 has an array of vertical posts ("standards") 12A, 1 2B, at appropriate spacings. In this example, there are two rows of standards. Each has a base plate 14 to prevent the bottom of the standard 12 sinking into the ground. Two ledgers 16 run horizontally along the lines of standards 12A, 12B, just above the base plates 14 and thus, at the bottom of the "base lift". Each ledger 16 may be a single pole or a series of poles, connected end-to-end.

Transoms 18 are installed at the level of the ledgers 16, and perpendicular to them, to complete a square grid interconnecting the standards 12, at the bottom of the base lift.

A second set of ledgers 1 6A and transoms 1 8A are provided at the top of the base lift, typically 2m above the ledgers 16. This provides adequate clearance for the heads of personnel in the base lift but also allows the ledgers 16A and transoms 18A to be installed by personnel in the base lift, reaching above their heads.

Various joints are made between the ledgers 16, transoms 18 and standards 12, by means of conventional scaffold clamps, which are not shown in the interests of clarity. Many designs of suitable clamps will be known to the skilled reader. The ledgers, transoms and standards are described herein as separate elongate members, in common with conventional practice, but could be members of modular systems of more complex form.

Stability of the scaffolding may be further improved by the provision of optional diagonal braces 20, particularly in the base lift.

The ledgers 1 6A and transoms 1 8A complete the formation of the base lift, but also serve to define the bottom level of the next highest lift (normally called the 'first lift"). The first lift (and higher lifts) will normally include eee. e ë.

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additional transoms 24, in addition to transoms extending between the standards 12B. This allows scaffold boards to be laid on the transoms 18A, 24 to provide decking on which personnel may stand.

It is envisaged in this description that the standards 12A will, in use, lie along the outer face of a wall or other structure against which the scaffolding is being constructed, with the standards 12B facing away from the structure. Consequently the risk of personnel falling from the scaffolding 10 arises primarily between the standards 12B. Accordingly, at least one horizontal guard rail 22 is installed along the standards 12B at an appropriate height, such as 1 m above the ledgers 16.

The ledgers 16A, transoms 18A, 24 and scaffold boards for the first lift can all be installed from below, by personnel working in the base lift, and protected by the guard rail 22. However, after the installation of scaffold boards for the first lift, the first lift remains unsafe for personnel, being without a guard rail. A guard rail at an appropriate height on the first lift is too high to be reached by personnel from the base lift. A device can now be described, which addresses this difficulty.

Scaffolding Construction Device Fig. 2 shows a scaffolding construction device 30. The principal component is an elongate post member 32. At one end of the post 32, a handle member 34 is mounted at 36 on the post 32, such as by a mounting bolt. A handle 38 has a handle aperture 40 above a lower edge formed to provide two hook recesses 42, the purpose of which will be explained more fully below.

Further toward the other end of the post 32, two releasable guard rail clamp arrangements 44 are provided. Each clamp 44 is a claw formation, . . e.

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shown more clearly in Fig. 3, mounted on the post 32 by means of a threaded bar indicated at 46. The hooked region 48 of the clamp 44 defines a recess which faces the post 32 and is shaped to receive a guard rail indicated at 52. The clamp 44 also has a temminal portion 54 through which the threaded bar 46 extends. A cooperating nut 56, threaded on the bar 46 allows the terminal portion 54 to be tightened against the post 32, thereby pulling the hooked region 48 toward the post 32 and clamping a guard rail 52, received in the recess 50, against the post 32.

The terminal portion 54 also carries fingers 58 which embrace the post 32 when the nut 56 is tightened, as can be seen in Fig. 3C. This embrace prevents the clamp 44 fuming around the bar 46, when the nut 56 is being tightened. However, the recess 60, defined by the fingers 58, is relatively 1 5 shallow so that it is only necessary to release the nut 56 slightly, to allow the fingers 58 to move clear of the post 32, and then allow the clamp 44 to rotate around the bar 46. The significance of this will be explained more fully below.

The hooked region 48 is formed from strip material, preferably pressed metal, which is relatively narrow in the direction 62, perpendicular to the post 32. The direction 62 corresponds with the longitudinal direction of a guard rail 52. Consequently, the clamp 44, even when fully tightened, allows the guard rail 52 some freedom to pivot at the clamp 44, relative to the post 32, but the guard rail 52 is prevented from sliding through the clamp 44, or from transverse movement away from the position at which it is clamped. The significance of this will be explained further, below.

Retuming to Fig. 2, a pivot arrangement 64 can be seen, secured to the post 32 at a position between the clamps 44 and the handle member 34.

The pivot arrangement 64 can be described in more detail, with reference to Fig. 4.

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Pivot Arrangement The pivot arrangement 64 has an intermediate arm 66 carrying two ears 68 at one end. The ears 68 are spaced to receive the post 32 between them, and each has an aperture 70 to receive a bolt 72 (Fig. 2) which passes through the apertures 70 and through a slot 74 formed in the post 32. The slot 74 is elongate, running generally longitudinally along the post 32.

Accordingly, the bolt 72 provides a pivot axis about which the arm 66 can swivel relative to the post 32, but the axis can move along the post 32, subject to the confinement of the bolt 72 in the slot 74.

At its other end, the intermediate arm 66, an arrangement is provided to receive a ledger as indicated at 80. In one example (Fig. 4) a collar 76 defines a recess 78. A ledger 80 received in the recess 78 will be centered at the centre 82 of the arcuate walls 84 of the recess 78.

A fixed nut 86 is mounted on the intermediate arm 66 and receives a rotatable bolt 88, which is therefore free to advance and withdraw along a line 90. It is to be noted that the line 90 does not pass through the centre 82.

Accordingly, as the bolt 88 is advanced, engagement will occur with the ledger 80, but not by the end face 92 of the bolt 88. Rather, the edge 94 of the end face 92 will engage the ledger 80. Tightening the bolt 88 will cause the edge 94 to engage tightly the ledger 80, perhaps even digging into the material of the ledger 80. This provides a secure mounting of the arm 66 on the ledger 80 and in particular, resists rotation of the arm 66 in the direction 96, relative to the ledger 80.

An alternative arrangement for the arm 66 (Fig. 2) has separate clamp plates 76A which are held together by a bolt 76B.

e.- .e ::: : .:: . - - Summarv The features of the device 30, as described above, can therefore be summarised as follows.

The device 30 is in the form of a post 32 which carries a handle member 34 at one end. Two clamps 44 are provided toward the other end, able to clamp guard rails 52 to the post 32. A pivot arrangement is provided l O at 64, which comprises an intermediate arm 66 connected to pivot on the post 32, and also to slide along it, and also providing a clamp arrangement by which the other end of the intermediate arm 66 can be securely clamped to a ledger 80.

It is important to note that the intermediate arm 66 separates the pivot axis from the clamp position.

Installing Guard Rails Retuming now to Fig. 1, the use of devices 30 for installing guard rails at higher levels can now be described.

First, personnel working from the base lift install at least two devices 30 by clamping the intermediate arms 66 to the ledgers 16A at the top of the base lift. The arms 66 are oriented to be generally upright (Fig. 5), so that the pivot axis with the post 32 is spaced above the ledger 1 6A to which the arm 66 is clamped by means of the bolt 88. This arrangement is shown in detail in Fig. 5, and schematically in Fig. 6, which illustrates two devices 30 installed as described.

In Figs. 5 and 6, it can be seen that the posts 32 have been brought to a generally upright position. The dimensions of the post 32 are chosen so @ . . . e that in this position, the handle member 34 is at the same level as the guard rail 22. The handle 38 allows the handle member 34 and post 32 to be lifted slightly (moving the post 32 past the bolt 72, by virtue of the slot 74), so that the hooked region 48 can be placed over the guard rail 22. This hooks the lower extremity of the post 32 onto the guard rail 22, retaining the post 32 in the upright position shown.

However, after the intermediate arm 66 has been adequately secured to the ledger 16A, the handle member 34 is released from the guard rail 22 and pushed out from the lift, allowing the post 32 to swing over on the bolt 72, to lie across the transoms 18A. Fig. 7 shows the original upright position of the posts 32 in broken lines, and solid lines are used to show the position of the posts after they have been swung over, as described. This operation of 1 5 swinging the posts over can be implemented from the base lift.

Prior to swinging over the posts 32, two lengths of guard rail 98 are pushed up from below, and laid on the transoms 18A, 24, along the length of the lifts. Thus, as the posts 32 lie across the transoms 18A, 24, they lie on top of the guard rails 98. This allows the clamps 44 to be manipulated by personnel in the base lift, to clamp the guard rails 98 to the posts 32. It is important to note that this operation is achieved from the base lift, while the personnel remain adequately protected by the guard rail 22.

After the guard rail 98 has been clamped to the posts 32, the weight of the guard rail 98 will tend to retain the posts in the position shown in Fig. 6.

The posts 32 will be inclined down from the horizontal, in this position, as indicated in Fig. 5, by virtue of the separation of the pivot axis above the position at which the intermediate arm 66 is clamped to a ledger. The length of post lying over the transoms can be changed by changing the length of the arms 66, but without changing the length of the post which extends above the ledger, when the post is upright.

: : . : .. . ...

Personnel can now reach out from the base lift, remaining protected by the guard rail 22, to grasp the post 32 beyond the intemmediate arm 66, pulling down on the free end to swing the post 32 back to the upright position. This results in the position of Fig. 8. The posts 32 are upright. The guard rails 98 have swung up to a horizontal position alongside the standards 28. The handle member 34 can be hooked onto the guard rail 22 by means of the bolt 72 and slot 74, thereafter retaining the posts 32 in their upright position and thus retaining the guard rails 98 at the position shown in Fig. 8. This provides temporary (but adequate) guard rail provision for the first lift, allowing personnel to ascend to the first lift. Permanent clamps are then used to mount the guard rails 98 to the standards 12. Once that has been done, the clamps 44 can be released. This allows the pivot arrangements 64 to be disconnected from the ledgers 16A. The devices 30 are then free to be re used, from the higher level which has just been constructed (in this case the first lift) to construct a further higher level in similar manner.

Thus, the device 30 allows construction of a higher level to proceed initially entirely from the level below, already provided with adequate safety provision, and then to provide adequate temporary guard rails for personnel to ascend to the higher level to complete the level by permanently securing the guard rails.

It is to be noted that the devices 30 will usually be sufficiently far apart to prevent a single workman grasping more than one device 30. However, it is nevertheless possible for a workman to work alone. This arises because the relatively loose hold provided by the clamps 44, allowing some pivoting between the guard rail and the post 32, allows the post 32 of one device 30 to be raised while the posts 32 of the other device 30 remains in the laid over condition. Some twisting and skewing in the clamps 44 will occur, to allow this. Thus, a single workman may raise one post 32, engage the handle : . . '.: . . . . . . . . ...

member 34 onto the guard rail 22, and then move to the other device 30, to repeat the action.

The design of the clamp arrangement (Fig. 3) allows guard rails to be quickly clamped to or released from the pivot members, because only slight movement of the clamps 44 along their bolts 46 is required to release the fingers 58 from the post member 32, allowing the clamps 44 to swing away and release the guard rail.

The length of the post beyond the pivot is less than the length above the ledger, when upright, as noted above. This arises from the separation provided by the intermediate arm. Accordingly, the choice of an appropriate arm length allows the procedure to be used even with narrow lifts, without affecting the final height of ground rails.

Variations and Modifications Many variations and modifications can be made to the apparatus described above. In particular, dimensions and relative dimensions of many components can be varied without changing the underlying operating principles used.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

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Claims (22)

1. A device for use in the construction of scaffolding, comprising: a post member; at least one releasable guard rail clamp arrangement operable to attach a guard rail to the post member; a pivot arrangement operable to provide pivotal attachment between the post member and a scaffolding member, whereby a guard rail attached to the post member may be raised and lowered by pivoting the post member; a holding arrangement operable to releasabl hold the post member against pivoting, whereby to hold a guard rail in a rain ad position; wherein the pivot arrangement comprises an atta;hment arrangement for attachment to a scaffolding member, and defines pivot axis for the post member, the pivot axis being, in use, spaced above the attachment arrangement, whereby the vertical length of the po t above the scaffolding member, when the post member is in the raised post-ion, is greater than the length of the post member above the pivot axis.

2. A device according to claim 1, wherein the attachment arrangement attaches, in use, to a scaffolding ledger.

3. A device according to claim 1 or 2, who rein the attachment arrangement includes a collar locatable around a so Ffolding member, and a threaded arrangement operable to tigh an against a member in the collar, to secure the attachment member to the m' mber.

4. A device according to claim 3, whe ein the collar is shaped to fit over a scaffolding member, in use, whereby to Rapport at least some of the weight of the device on the member prior to the th added arrangement being tightened.

5. A device according to claim 3 or 4, wherein the threaded arrangement includes an elongate threaded member rotatably mounted in the pivot arrangement to be advanced, by rotation, to grip a scaffolding member received in the collar.

6. A device according to claim 5, wherein the elongate threaded member has an axis which does not intersect the member axis defined by the collar, whereby the threaded member obliquely engages a member received in the l O collar, to resist rotation of the collar relative to the member.

7. A device according to any preceding claim, wherein the pivot arrangement comprises an intermediate member which provides the attachment arrangement and a pivot axis defining arrangement at respective positions along its length.

8. A device according to claim 7, wherein the pivot axis defining arrangement includes a pivot pin projecting from the intermediate member and through the post member.

9. A device according to claim 7 or 8, wherein the pivot axis defining arrangement comprises a pair of arms which embrace the post member, the pivot pin extending between the arms.

10. A device according to claim 8 or 9, wherein the pivot pin is located in a slot formed in the post member, whereby the post member is movable in a longitudinal direction relative to the pivot pin.

11. A device according to any preceding claim, wherein the holding arrangement acts, in use, between the post member and a fixed member located below the pivot member.

12. A device according to claim 11, wherein the fixed member is a guard rail.

13. A device according to any preceding claim, wherein the holding arrangement comprises a hooked member.

14. A device according to claim 13, wherein the hooked member is mounted on the post member and is movable transversely of the pivot axis for l O engagement and disengagement with the fixed member.

15. A device according to any preceding claim, wherein the guard rail clamp arrangement includes a clamp arm mounted on the post member and movable to clamp a guard rail against the post member, the clamp arm being also mounted to pivot away from the guard rail upon its release.

16. A device according to claim 15, wherein the clamp arrangement comprises a pivot pin around which the clamp arm may pivot.

17. A device according to claim 15 or 16, wherein the clamp arrangement comprises engaging means operable to engage the post member as the clamp arm clamps a guard rail, to resist pivoting.

18. A device according to claim 15, 16 or 17, wherein the engaging means comprises fingers which embrace the post member to resist pivoting, and which release the post member as the clamp arm releases the guard rail.

19. A device according to any of claims 15 to 18, wherein the clamp arm is mounted by means of an elongate threaded member through the clamp arm and the post member, the elongate threaded member cooperating with a further threaded member to create clamping movement, and cooperating with the clamp arm to provide pivotal movement of the clamp arm around the threaded member.

20. A method of installing guard rails for scaffolding which has at least one level above which a scaffolding member is installed for supporting a higher level, in which at least two devices as defined above are pivotally attached to the member by means of the respective pivot arrangements, the post members are pivoted over to lie across the said higher level, at least one guard rail is attached to the post members while they are lying across the said higher level, the post members are brought to their substantially upright positions by means of the pivot arrangements thereby moving the guard rail to a temporary position, guarding the said higher level, and the holding arrangements are engaged to hold the post members in the raised positions.

21. A device for use in the construction of scaffolding, substantially as described above, with reference to the accompanying drawings.

22. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.