WO1994028268A1

WO1994028268A1 - Anchoring device for use on a roof

Info

Publication number: WO1994028268A1
Application number: PCT/GB1994/001130
Authority: WO
Inventors: Henry Crawford; Derek Roy Cowe
Original assignee: Dunn & Cowe Limited
Priority date: 1993-05-26
Filing date: 1994-05-24
Publication date: 1994-12-08
Also published as: AU6760194A; GB2292583A; GB2292583B; GB9523340D0

Abstract

An anchoring device (10; 110) for use on a roof having a plurality of trusses (12) with external covering means (14; 16; 22) is described. The anchoring device (10; 110) includes truss attachment means (26) for securing the anchor to a truss (12) and a roof anchor (28) which is coupled to the truss attachment means (26) and which passes through the roof covering (14; 16; 22) to provide an anchor point. The truss attachment means (26) has upper and lower plates (30; 32) for engaging with respective upper and lower faces of the truss (12). The plates are connected by side members (34; 36) for location to respective sides of the truss (12), the spacing between the side members (34; 36) being adjustable to accommodate trusses of different widths. The anchor point can be provided by an eye (52) or a hook (66) or both and a ladder or crawler board (116) or scaffolding frame (202; 218) can be secured to the anchoring device by the eye or hook to facilitate a safer working environment. Embodiments of the invention are described.

Description

ANCHORING DEVICE FOR USE ON A ROOF

This invention relates to an anchoring device for use on a roof having a truss or a plurality of trusses with external covering means thereon. The device may provide an anchorage to which a lanyard or safety harness may be secured, or from which a roof ladder may be suspended, or on which a crawler board or working platform or safety rail may be mounted, or which may be used as an anchor for horizontal flexible anchorage lines.

Conventional anchoring devices may be secured to various elements of a roof, such as a roof truss or ridge, so that an anchoring element, typically an eye-bolt, projects through the roof surface. Examples of existing anchors are disclosed in UK Patent Applications GB 2 251 020 A and GB 2 259 527 A. The anchor disclosed in GB 2 251 020 A includes a generally U-shaped rafter bracket which is clamped to a truss or rafter using a U-bolt, the free ends of which pass through apertures in flanges of the bracket and are secured to a plate beneath the bracket. A pedestal is secured to the bracket and provides mounting for an eye-bolt which extends through the roof covering. While such anchors have proved satisfactory in use, both the U-shaped bracket and the U-bolt are adapted to fit snugly around the a roof truss such that if anchors are to be fitted to trusses of different sizes, various sizes of brackets must be produced.

It is among the objects of at least one aspect of the present invention to provide an anchoring device which may be readily adapted to accommodate trusses of different dimensions.

According to the present invention there is provided an anchoring device for use on a roof having a truss or a plurality of trusses with external covering means thereon, the device comprising truss attachment means for securing to a truss and roof anchor means for fixing to the attachment means and extending through the roof covering to provide an anchor point, the attachment means including upper and lower members for engaging the respective upper and lower faces of the truss and the members being connected by side members for location to the respective sides of the truss, the spacing between the side members being adjustable to accommodate trusses of different dimensions.

The adjustability of the device allows a single size of anchoring device to be provided for use on a variety of roof types and constructions, without modification.

The upper and lower members may bear directly on the respective faces of the truss, or other roof elements or parts of the device may be located therebetween.

Preferably, the upper and lower members are in the form of plates, and the side members may be in the form of bolts or pins. In a preferred form, upper and lower plates are provided with a plurality of laterally spaced bolt receiving openings, side bolts being located in the openings to provide the smallest possible lateral spacing between the bolts, while accommodating the truss width. Alternatively, the bolt openings may be in the form of laterally extending slots.

The roof anchor means may be provided with one or both of a harness attachment means and a hook for projecting above the roof covering. The harness attachment means may be in the form of an eye. The hook may be adapted to receive a rung of a ladder to be laid on the roof or may be adapted to support one end of a crawler board or a work platform. The hook may also receive scaffolding poles which are coupled to a safety rail located at the roof edge. Conveniently, the hook is provided with a clamp arrangement for securing the rung of a ladder in the hook, or clamping a portion of a crawler board in the hook. If the hook is to be used to support a crawler board it is preferred that the hook is reinforced. The eye can also receive a bolt for being coupled to scaffolding poles extending generally at right angles to the edge of the roof, these poles also being coupled to a safety rail.

Alternatively, the roof anchor means may be provided with means for anchoring a section of a horizontal flexible anchorage line. Preferably also, the attachment means further includes an anchor mounting portion for clamping to the truss. Most preferably, the mounting portion includes a part for engaging a side of the truss and a part for engaging the lower face of the truss. Preferably, the roof anchor means is secured to the mounting portion at least at spaced upper and lower points. Most preferably, the roof anchor means includes support means for securing to the mounting portion, the support means having a cross-section sufficient to provide a modulus of stiffness so that the anchor means is subject to minimal deflection when loaded under intended conditions.

Preferably also, the anchor means is adjustable to accommodate different spacings between the truss and the outer surface of the roof covering. This may be achieved by arranging the support means to be slidably moveable relative to the mounting portion. Most preferably, one of the mounting points is in the form of a clamp which may be loosened to allow for such adjustment. In a preferred arrangement the lower mounting point is in the form of a clamp, while the upper mounting point is provided by an aperture in the upper part of an S-shaped mounting portion.

According to a further aspect of the present invention there is provided an anchoring device for use on a roof having a plurality of trusses with external covering means thereon, the device comprising truss attachment means for securing to a truss and roof anchor means for fixing to the attachment means and extending through the roof covering to provide an anchor point, the roof anchor means including a hook for receiving and supporting a crawler board.

In use, at least two devices will be provided on a roof, spaced apart and at the same level, such that a crawler board may be mounted between the devices to provide a working platform. The device has particular application for use on "fragile" roofs, such as those formed of asbestos sheet, which will not support a person's weight without the load being spread by means of crawler boards and the like.

Preferably, the hook includes a clamping means for securing a board or pole in the hook. Conveniently, the clamping means is in the form of a screw located in a threaded aperture in the hook, such that the end of the screw may be brought into clamping engagement with an upper surface of a board or trap a scaffolding pole or the like when located in the hook.

Preferably also, the anchor means is provided with harness attachment means, such that a person working on a crawler board supported by the device may attach a safety line to the device. Conveniently, the harness attachment means is in the form of an eye. The eye can also be used to receive a bolt to couple the anchor means to a scaffolding pole or similar support for connection to a safety rail located at the roof edge. These and other aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a sectional side view of an anchoring device in accordance with a first embodiment of the present invention, shown fitted on a roof;

Figure 2 is a perspective view from above of the anchoring device of Figure 1;

Figure 3 is a plan view of an upper plate of the device of Figure 1;

Figure 4 is a sectional side view of an anchoring device in accordance with a second embodiment of the present invention;

Figure 5 is a perspective view from above the anchoring device of Figure 4;

Figures 6 and 7 are perspective views of a number of the anchoring devices of Figure 4 in use;

Figure 8 is a side view of an anchoring device in accordance with a third embodiment of the present invention;

Figure 9 is a perspective view of a number of the anchoring devices of Figures 4 and 8 in use;

Figure 10a or 10b are perspective, and enlarged and partly exploded details, respectively of an anchoring device as shown in Figures 1 to 3 used to couple scaffolding poles and a safety rail thereto via the eye of the anchoring device, and Figures 11a and lib are similar views to Figures 10a and 10b in which the anchoring device of the second embodiment of the invention, as shown in Figures 4 and 5, is shown retaining scaffolding coupled to a safety rail.

Reference is first made to Figure 1 of the drawings which illustrates an anchoring device 10 in accordance with a preferred embodiment of the present invention, shown mounted on a roof to provide an anchor for receiving a lanyard or safety harness and also to provide safe mounting for a roof ladder. The particular roof construction illustrated in merely one example of the many forms of roof on which the device 10 may be utilised, the common feature of such roofs being that the roof covering is supported by plurality of trusses 12. In this roof, timber sarking 14, formed of interlocked boards 16, is mounted directly on the upper faces of the trusses 12 and the sarking itself provides mounting for a plurality of counter battens 18 and tile battens 20. In other roofs, the sarking may not be present. Tiles 22 are suspended from the battens 20 in overlapping relation, though at the location where the upper end of the device 10 extends through the roof covering the tile has been replaced by a lead slate piece 24.

The anchoring device 10 comprises a truss attachment means 26 for securing to the truss 12 and a roof anchor means 28 which extends through the roof covering to provide the anchor point. The truss attachment means 26 includes a truss clamp formed of upper and lower plates 30, 32 for engaging the upper surface of the sarking 14 and the lower face of the truss 12, respectively, and two side bolts 34, 36 which hold the plates 30, 32 together. The bolts 34, 36 extend down the sides of the truss 12. Reference is now also made to Figures 2 and 3 of the drawings, from which it will be noted that the bolts 34, 36 are received in openings 38 in the plates 30, 32. As may be seen from Figure 3, the left hand side of the upper plate 30 is provided with a plurality of spaced openings 38a, 38b, 38c. A similar arrangement of openings is provided in the lower plate 32. The bolt 34 is located in the openings which permits the smallest lateral spacing between the bolts 34, 36, while accommodating the truss width. This provides for a more secure and stable attachment.

The truss attachment means 26 further includes an anchor mounting bracket 40, in the form of a flattened S-shape having upper, middle and lower parts 42, 44, 46. The plate 40 is fitted against the truss, and will likely also be nailed to the truss, with the lower part 46 engaging the lower face of the truss 12 and the middle part 44 engaging a side face of the truss. The upper part 42 lies flush with or slightly below the upper face of the truss 12 and below the sarking 14. The lower part 46 is positioned between the lower surface of the truss 12 and the lower plate 32, and the bolt 36 extends through an aperture 48 formed in the upper part of the plate 42.

The roof anchor means 28 includes a support pedestal 50 and an eye-bolt 52 which is mounted in the pedestal 50. The plate 40 has an aperture in the upper part 42 to receive the pedestal and is also provided with a clamp 54 on the central part 44 which may be loosened to allow sliding of the pedestal relative to the plate 40. The clamp 54 includes an L-shaped bracket 55 which receives a bolt for engaging a threaded boss welded to the bracket 40,

The upper end of the pedestal 50 is arranged to engage the lower surface of the slate piece 24 and is provided with a convex washer 56 which, together with the concave washer 58 provided on the eye-bolt 52, forms a weatherproof seal around the aperture in the slate piece 24, as described in more detail in GB 2 259 527 A.

The eye-bolt 52 has a threaded lower end 60 which extends from the lower end of the pedestal 50 and is held in place by a nut and washer arrangement 62. The upper end of the eye-bolt 52 is formed and welded to define the eye 64 and a steel strip 66 is welded to the upper end of the bolt 52 to form a ladder hook.

The anchoring device is straightforward to install: first, tiles 22 are removed to expose the sarking 14. The bracket 40 is then nailed in place and a hole is drilled through the sarking to receive the pedestal 50. Two smaller holes are drilled through the sarking using the appropriate apertures 38 in the plate 30 as templates. The bolts 34, 36 are passed through the holes from the roof side and fastened securely around the bracket 40 and the truss 12 by the plate 32 and nuts 37 (only one nut visible in the drawings) .

The pedestal 50 is then passed through the hole in the sarking and the aperture 48 and is adjusted to a suitable height, as shown in Figure 1. At this height the bolt is tightened to clamp the pedestal 50 with bracket 55. The slate piece 24 is then fitted and is secured at the top of the pedestal between the washers 56, 58 to form a waterproof seal. The tiles 22 around the device 10 are then replaced.

Of course, in a roof without sarking it will not be necessary to drill the various holes mentioned above.

It will be appreciated from the above description that the anchoring device 10 offers the advantages offered by the somewhat similar anchor of GB 2 251 020 A and, due to the configuration of the plates 30, 32 and bracket 40, and also the use of individual bolts 34, 36, allows the device 10 to be mounted on trusses of various widths. Also, the device may be fitted to trusses 12 of various heights.

Reference is now made to Figures 4 and 5 of the drawings, which illustrate an anchoring device 110 in accordance with a second embodiment of the present invention. It will be noted that the device 110 is substantially similar to the device 10 described above, and like reference numerals will be used for the common parts. Further, in view of these similarities only the differences between the two devices 10, 110 will be described in any detail.

The roof anchor means 28 includes an eye-bolt 52 with an upper end formed and welded to define an eye 64 and a steel strip 66 is welded to the upper end of the bolt 52 to define a hook. Further, a reinforcing strip 112 is welded between the eye 64 and the strip 66. A threaded aperture is provided through the strips 66, 112 and receives a bolt, in this example a smaller eyebolt or bolt 114 (Figure lib) , which may be tightened to clamp or retain an object located in the hook defined by the strip 66. Figure 4 shows the end of a crawler board 116 clamped in the device 110.

Reference is now made to Figure 6 of the drawings which illustrate three devices 110 provided on a roof surface 118. Two of the devices 110a,b provide support for a crawler board 116 while the third device 110c provides support for a ladder 120. It will be further noted that the operator's safety line 122 is attached to the eye 64 of the bolt 52 of one of the devices 110b.

Reference is now also made to Figure 7 of the drawings which illustrates two devices 110 providing support for a work platform 124 below a chimney stack 126.

Any number of device 110 may be provided on a roof, and may extend over the length of the roof to allow crawler boards to extend over the entire roof. Alternatively, devices may be provided only at particular locations where a work platform will be required at more frequent intervals, such as at a skylight 124, as shown in Figure 6, below a chimney stack, as shown in Figure 7, or below a roof mounted aerial. Of course, the device 110 may also be used solely to provide an attachment point for an operator's safety line or harness, particularly for jobs of short duration on roofs formed of non-fragile materials, on which an operator may work safely without the requirement for crawler boards.

Reference is now made to Figures 8 and 9 of the drawings which illustrate a further application for a device 150 in accordance with a further aspect of the invention, that is providing an anchor for flexible anchorage lines 152.

The device 150 may be secured to a roof truss in the same manner as the devices 10, 110 described above, or, as illustrated, using another form of anchor. However, the support pedestal 154 is of different construction from the pedestal 50 described above, set out below. For this particular application the pedestal 154 is longer than the pedestals 50 described above such that the anchorage line 152 is held spaced from the roof surface 156. This avoids the line 152 contacting the surface 156, which would otherwise produce noise and possibly damage the roof covering. However, in view of its greater length, a greater moment will be exerted on the pedestal 154 in the event of the line 152 arresting a fall. Accordingly, the pedestal 154 comprises a solid tapped bar 158, the eye 160 for the anchorage line 152 being mounted on a short drilled bar 162 bolted to the upper end of the bar 158.

The greater length of the pedestal 154 requires provision of a different sealing arrangement to that described above, and thus the concave sealing washer 58 is mounted on the lower end of a sleeve 164 which is welded to the drilled bar 162.

A "penny" washer 165 is mounted on the lower end of the tapped bar 158 by a bolt 166, which washer 165 will prevent the bar 158 being pulled from the clamp 54 in the event that, for example, the bolt on the bracket 55 has not been properly tightened.

As illustrated in Figure 9, an operator may attach a safety line 122 to the anchorage line 152, allowing relatively free movement along a roof surface.

Reference is now made to Figures 10a and 10b of the drawings which depict a plurality of roof anchors 10 disposed parallel to the edge 200 of a roof 202. Scaffolding poles 204 lie at right angles to the roof-edge and have a tubular end piece 206 with a welded stud 208. Each pole is secured to a respective anchor by the stud 208 which passes through the eye-bolt 52 to be engaged by a washer 212 and nut 214. The other ends of the poles are secured to scaffolding brackets 216 which, in turn. support a handrail 218 which lies on a piece of timber 219 at the edge of the roof. The welded stud may be replaced by an aperture and a bolt passed through the aperture and eyebolt 52 to engage with nut 54. The roof anchors 10 allow such handrails to be rapidly assembled and easily installed to provide a safe working environment on the roof which has hitherto not been possible to do with existing roof anchors.

Reference is now made to Figures 11a and lib of the drawings which depict the roof anchors 110, as shown in Figures 4 and 5, replacing roof anchors 10 to secure poles 204 and rail 218. In this case cross poles 220 are connected to poles 204 by T-shaped brackets 222 and the cross-poles 200 lie in the hook defined by the strip 66. The bolts 114 are then screwed down to secure the pole 220 in hooks so that the entire frame and handrail 218 is secured to the roof anchors 110. This arrangement has the advantage that it uses conventional scaffolding without requiring a piece with an aperture or fastening a nut to a bolt. This can be rapidly installed.

It will be clear to those of skill in the art that the abovedescribed embodiments are merely exemplary of the present invention, and that various modifications may be made to the devices illustrated without departing from the scope of the invention, for example: a U-bolt of appropriate size may be used in place of the individual bolts 34, 36 if the width of the truss is known beforehand; and transverse slots may be provided in the plates 30, 32 in place of the spaced openings 28a, 38b, 38c. With such an arrangement, the hex-headed bolt 34 may be replaced with a dome-headed bolt with a square section below the head capable of sliding along the slot and which obviates the need for an operator to hold the bolt while the nut 37 is tightened.

Claims

1. An anchoring device for use on a roof having a plurality of trusses with external covering means thereon, the device comprising truss attachment means for securing to a truss and roof anchor means for fixing to the attachment means and extending through the roof covering to provide an anchor point, the attachment means including upper and lower members for engaging the respective upper and lower faces of the truss and the members being connected by side members for location to the respective sides of the truss, the spacing between the side members being adjustable to accommodate trusses of different dimensions.

2. An anchoring device as claimed in claim 1 wherein the upper and lower members bear directly on the respective faces of the truss.

3. An anchoring device as claimed in claim 1 wherein the upper and lower members have other roof elements or parts of the device located between the upper and lower members and the respective faces of the truss.

4. An anchoring device as claimed in any preceding claim wherein the upper and lower members are in the form of plates, and the side members are in the form of bolts or pins.

5. An anchoring device as claimed in claim 4 wherein upper and lower plates are provided with a plurality of laterally spaced bolt receiving openings, side bolts being located in the openings to provide the smallest possible lateral spacing between the bolts, while accommodating the truss width.

6. An anchoring device as claimed in claim 4 wherein the upper and lower plates are provided with bolt openings in the form of laterally extending slots.

7. An anchoring device as claimed in any preceding claim wherein the roof anchor means is provided with one or both of a harness attachment means and a hook for projecting above the roof covering.

8. An anchoring device as claimed in claim 7 wherein the harness attachment means is in the form of an eye.

9. An anchoring device as claimed in claim 7 or claim 8 wherein the hook is adapted to receive a rung of a ladder to be laid on the roof or is adapted to support one end of a crawler board or a work platform.

10. An anchoring device as claimed in claim 7, 8 or 9 wherein the hook is provided with a clamp arrangement for securing the rung of a ladder in the hook, or clamping a portion of a crawler board in the hook.

11. An anchoring device as claimed in claim 7 wherein the roof anchor means is provided with means for anchoring a section of a horizontal flexible anchorage line.

12. An anchoring device as claimed in any preceding claim wherein the attachment means further includes an anchor mounting portion for clamping to the truss.

13. An anchoring device as claimed in claim 12 wherein the mounting portion includes a part for engaging a side of the truss and a part for engaging the lower face of the truss.

14. An anchoring device as claimed in claim 13 wherein the roof anchor means is secured to the mounting portion at least at spaced upper and lower points.

15. An anchoring device as claimed in any one of claims 12 to 14 wherein the roof anchor means includes support means for securing to the mounting portion, the support means having a cross-section sufficient to provide a modulus of stiffness so that the anchor means is subject to minimal deflection when loaded under intended conditions.

16. An anchoring device as claimed in any preceding claim wherein the anchor means is adjustable to accommodate different spacings between the truss and the outer surface of the roof covering.

17. An anchoring device as claimed in claim 16 wherein the adjustment is by arranging the support means to be slidably moveable relative to the mounting portion.

18. An anchoring device as claimed in claim 16 or claim 17 wherein one of the mounting points is in the form of a clamp which is loosened to allow for such adjustment.

19. An anchoring device as claimed in claim 18 wherein the lower mounting point is in the form of a clamp, while the upper mounting point is provided by an aperture in the upper part of an S-shaped mounting portion.

20. An anchoring device for use on a roof having a plurality of trusses with external covering means thereon, the device comprising truss attachment means for securing to a truss and roof anchor means for fixing to the attachment means and extending through the roof covering to provide an anchor point, the roof anchor means including a hook for receiving and supporting a crawler board.

21. An anchoring device as claimed in claim 20 wherein at least two devices are provided on a roof, spaced apart and at the same level, such that a crawler board is mounted between the devices to provide a working platform.

22. An anchoring device as claimed in claim 20 or claim 21 wherein the hook includes a clamping means for securing a board or pole in the hook.

23. An anchoring device as claimed in claim 22 wherein the clamping means is in the form of a screw located in a threaded aperture in the hook, such that the end of the screw is brought into clamping engagement with an upper surface of a board or trap a scaffolding pole or the like when located in the hook.

24. An anchoring device as claimed in any one of claims 20 to 23 wherein the anchor means is provided with harness attachment means, such that a person working on a crawler board supported by the device may attach a safety line to the device.

25. An anchoring device as claimed in claim 24 wherein the harness attachment means is in the form of an eye.