PATENTS ACT 1990 (AS AMENDED) COMPLETE SPECIFICATION FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: Name of Applicant: Address of Applicant: Actual Inventor: TO BE COMPLETED BY APPLICANT James Laurence Curtin 68 St. George Crescent, SANDY POINT NSW 2171 AS ABOVE Address for Service: ANDERSON-TAYLOR ASSOCIATES, Registered Patent Attorneys of 10 Harrison Avenue BONNET BAY N.S.W. 2226 Complete Specification for the invention entitled: FALL ARREST ANCHOR POINT The following statement is a full description of this invention, including the best method of performing it known to me: This invention relates to height safety equipment. More particularly although not exclusively it discloses an improved fall arrest anchor point for use on metal frame roofs.
Fall arrest systems have been devised to protect persons working at heights. Typically one or more fall arrest anchor points are installed on a building roof to which a worker is attached by a line or cable. It is essential that the anchor point be capable of both withstanding the impact load imposed when arresting a fall and also attaching to the underlying roof members without structural impairment. With metal frame buildings such as commonly used for factories the roof structure typically comprises universal beams overlayed by purlins and then roof panels. The anchor points are fastened at their base to the beams with post sections extending up between the purlins and through the roof panels. As the size of these beams varies current practice is to custom design the anchor points for each building. This is expensive, time consuming and commonly involves welding with resulting brittleness problems.
It is therefore an object of this invention to ameliorate the aforementioned disadvantages and accordingly a fall arrest anchor point for use in a building roof structure is disclosed, the anchor point including a sole plate having on an underside a clamp means and on an upper face an upstanding post with line attachment means at or adjacent the top thereof, a brace extending between said post intermediate the ends thereof and spaced apart locations on said sole plate whereby in use of the anchor point the sole plate can be fitted across an upper flange of a roof support beam with said clamp means being adjustable to tightly grip opposite edges of the flange so that said anchor point is fixed in place against fall arrest loading and said post extends up through a roof panel to expose said line attachment means for connection to a working line.
Preferably the anchor point is constructed without the use of welds.
It is further preferred that said clamp means comprises clamp blocks which are slidably adjustable by means of elongated bolt holes in said blocks.
The invention is further described with reference to the attached drawings in which: figure 1 figure figure shows a schematic perspective view of a first embodiment of the anchor point, shows a side view of the anchor point, shows a cross-sectional view along the lines A-A of figure 2, shows an side view of the anchor point when installed in a roof structure, and is a perspective view of a second embodiment figure 4 figure 5 -3of the anchor point.
Referring first to figures 1 to 4 the anchor point may comprise a sole plate 1 with a pair of clamp blocks 2 on the underside and an upstanding threaded post 3 (preferably of about 24 mm diameter) centrally located on the upper plate face 4. The post is supported by a brace which comprises a planar midsection 6, inclined sides 7 and base flanges 8 attached adjacent opposite ends of the sole plate. The post extends through the midsection 6 and is locked in place by nuts 9 and 10. The lower end of the post also threads into the centre of the sole plate and is locked by a nut 11. The upper end of the post is fitted with an eye bolt 11A for connection to a working line as described in more detail later.
In accordance with this invention the clamp blocks 2 are L shaped with inwardly directed pawls 12. They are attached to the underside of the sole plate by four bolts 13 which also extend through and secure the base flanges 8 of the post brace. With this embodiment the upper plate engaging faces 14 of the blocks are bevelled at about 4 degrees so that said blocks tilt inward and upward when the bolts 13 are tightened. Although not shown in the drawings the bolt receiving holes in the blocks are elongated to enable lateral adjustment of the clamp as indicated by arrows B. With the described embodiment the amount of adjustment available for each block is preferably about 13 mm. This however may be -4varied according to design requirements.
In use the anchor member as shown in figure 4 is fitted into a building roof structure by placing the sole plate across the upper flange 15 of an existing univeral beam. The dimensions of the sole plate (preferably about 125 mm width and 260 mm length) and the available lateral adjustment of the clamp blocks mentioned earlier allow the device to be used with a wide range of common beam sizes. With the sole plate in position the clamp blocks are slid inwardly until the pawls engage under the flange 14 and the shoulders abut the flange edges 14A. The bolts 13 are then tightened so that the the blocks 2 are pulled inwardly and upwardly to grip said flange. The sole plate and post are thereby securely and permanently clamped against fall arrest loading. The upper end of the post extends up through an aperture in -the roof panel 16 to expose the eye bolt 11A for attachment of a working line. A ring 17 may also be formed at the base of the eye to seat rubber flashing skirt 18 for waterproofing the installation.
With the second embodiment of the invention as shown in figure 5 the components that correspond with those of figures 1 to 4 are identified by the same numbers which are however primed to distinguish them. In this case the upper end of the post 3' is formed with a mount 19 and threaded socket to receive a static line ring (not shown). Several such anchor points would typically be installed across a roof area with the static line extending between them. Working lines for individual personnel would then be attached to this static line.
It will thus be appreciated that this invention at least in the form of the embodiments described provides a novel and improved form of fall arrest member. Clearly however the examples disclosed are only the currently preferred forms of the invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For example the shape and bevel applied to the clamp blocks as well as the design and dimensions of the brace, sole plate and post may be changed according to application. Also, while the anchor point is preferably constructed from 760 grade steel or stainless steel the invention extends to the use of any other suitable material.