GUARD RAIL FOR THE RIDGE AND EAVE OF HOUSE ROOFS

Abstract: A guard rail for the ridge and eave of house roofs comprises at least two upright posts (10) adapted to be attached to the roof (12) at a distance from each other along the ridge or the eave (16) of the roof, and a rail bar (11) running between the posts (10). Each upright post (10) is provided with at least a portion (e.g. 13) adapted to obtain a permanent deformation, when the guard rail is exposed to a shock load from a falling human body who is connected to the guard rail by means of a line, so that the falling person is softly braked. Each post (10) consists preferably of a U-shaped support having two legs (13, 14) and a connecting portion (15). At least one leg (13, 14) and/or the connecting portion (15) obtains a permanent deformation during the braking of the body.

Description: Guard rail for the ridge and eave of house roofs Technical Field The present invention relates to a guard rail for the ridge and eave of house roofs, comprising at least two upright posts adapted to be attached to the roof at a dis- tance from each other along the ridge or the eave of the roof, and a rail bar running between the posts. The guard rail is intended to increase the safety of persons carrying out work on a roof, for example platers and snow shovel¬ lers, when moving on the roof, and to serve as a hold for life lines during such work. The guard rail is particularly intended to be set up on roofs of corrugated sheets but can also be set up on other roof constructions. Background Art It is previously known to provide guard rails along the ridges and eaves on house roofs, and standards have been issued for the design and dimensioning of such guard rails, for example the Swedish Standard 83 '13 01. These prior art guard rails consist of upright posts and rail bars, the upright posts being rigid supports unresiliently attached to latches or other fixed parts of the roof const¬ ruction, and the rail bars being rod-shaped elements each one running through or past at least two posts. Guard rails for ridges or eaves of the above mentioned design have at least two disadvantages. Firstly, the unre- siliently attached upright posts give a very abrupt braking of a person whose life line is attached to such a guard rail, if the person falls down from the roof. Such an abrupt braking can cause a situation in which the falling person is hurt by the life line. Secondly, the guard rails are difficult to set up on roofs of corrugated sheets, because the distance between the load carrying latches is long and other fixed parts of the roof construction normal¬ ly are unavailable in the positions where the guard rails are to be set up. Disclosure of Invention The main object of the invention is to provide a guard rail for ridges and eaves that gives a softer braking of a falling person having the life line attached to the guard rail. A further object of the invention is to provide a guard rail that is easy to set up on roofs of corrugated sheets, even if the sheets are comparatively thin, for example 0,5 millimetres. These objects are achieved with a guard rail for ridges and eaves having the features set forth in the claims. Brief Description of Drawings One embodiment of a guard rail for ridges and eaves according to the invention will now be further described below with reference to the accompanying drawings. Fig. 1 is a side view of a portion of a guard rail for an eave with an upright post and a rail bar, the guard rail being set up on a sloping roof of corrugated sheets. Fig. 2 is a view as seen from the ridge of the guard rail shown in Fig. 1. Best Mode for Carrying Out the Invention The guard rail shown in Figs. 1 and 2 comprises four upright posts 10 attached to the corrugated roof sheets 12, and one rail bar 11 attached to the four upright posts 10. The upright posts 10 consist of a substantially U-shaped support having two legs 13,14 and a connecting portion 15 running between the legs, as shown in Fig.l. The legs 13,14 have different lengths, the longer leg 13 facing the ridge and the shorter leg 14 facing the eave 16. The free ends of the legs 13,14 are attached to the sheets 12 in a way that will be further explained below. The connecting portion 15 between the legs is substantially straight and forms an angle of 23° with the plane of the roof sheets. The portion 15 is spaced from the roof sheets 12, and the distance is about 150 millimetres at the longer leg and about 40 milli¬ metres at the shorter leg. The portions of the support lie in a plane perpendicular to the roof sheets 12 and the roof eave 16. The rail bar 11 consists of an angle bar having two legs 17,18 forming an angle of 90° with each other,, and is attached to the upright posts 10 by means of screws 19 pas- sing through the one leg 17 and through the long leg 13 of the supports, the other leg 18 being extended over the upright posts 10 and abutting their connecting portions 15. The long leg 13 of the support, which leg faces the ridge, is at its free end bent to a lug 20 provided with a hole for a fastening screw 21. Said screw passes through the roof sheet 12 and engages with threads provided in a section bar 22 positioned under the roof sheet 12, as shown in Fig. 1. The section bar has a length which is substan¬ tially longer than the distance between the legs 13,14 of the support 10 and runs below the full length of the sup¬ port, so that also the other leg 14 of the support can be attached to the roof sheet 12 by means of the section bar 22. However, the leg 14 is attached to the roof sheet 12 by means of an angle bar 23 having two legs 24,25 which form a substantially right angle with each other, the leg 24 being attached to the leg 14 by means of a screw 26 and the leg 25 being attached to the section bar 22 by means of a screw 27 passing through an elastic washer 28, for example of butyl rubber, and the sheet 12. The angle bar 23 runs in parallel with the rail bar 11 and the eave 16 and has the same length as the rail bar, as shown in Fig. 2. The leg 24 of the angle bar has substantially the same height as the leg 14 of the support, so that the leg does not extend app¬ reciably over the angle bar. The section bar 22 is attached to the roof sheet 12 by means of a further screw 29. The angle bar 23 is intended to provide a foot hold for a person who may be sliding below the rail bar 11, and to prevent that snow, tools and material possibly lying on the roof can slide down from the roof. The upright posts 10, the rail bar 11, the section bar 22 and the angle bar 23 may consist of aluminium or of an aluminium alloy. The guard rail described above is intended to be posi¬ tioned either on or at the ridge of the house roof or at the eave to provide a support for persons who have to move over the roof, or to serve as a hold for life lines for the persons who work on the roof. The heaviest load on the guard rail arises when a person whose life line is attached to or adjacent an upright post falls over the edge of the roof. According to existing regulations the upright post must stand a pull in the life line from a falling body having the weight of 100 kilograms and falling 3 meters. In this load case the upright post in the guard rail according to the invention will operate in the following way, assu¬ ming that the life line is attached to the rail bar adja¬ cent an upright post. Due to the arising shock load, the longer leg 13 of the upright post at the point where it is fastened to the roof will be bent towards the eave. The angle bar 11 will then be turned, so that the angle leg 18 with its front edge, which extends over the post, forces the connecting portion 15 downwards, so that this portion is bent. At the same time also the shorter leg 14 of the upright post is moved towards the eave, so that the angle bar 23 is bent up over the fastening screw 27. Due to the displacement of the legs 13 and 14, the connecting portion 15 of the post which portion from the beginning was straight is bent upwards at the shorter leg 14 and downwards at the longer leg 13, so that the connecting portion obtains a permanent deformation with a substantial S-shape. Due to the bending and displa¬ cement of the legs 13 an ' d 14 and the deformation of the connecting portion 15 and of the angle bars 11 and 23 a soft braking of the falling body is obtained, so that the risk of injuries on the body is substantially reduced. Thus, all or at least most of the parts of the guard rail co-operate to provide a soft braking of the falling body. The turning of the rail bar 11 includes partly a tor- sional turning of an angle bar, because the angle bar is attached to the adjacent upright post, and this provides a good absorption of forces, and partly a downward bending of the connecting portion 15 adjacent the leg 13, and this facilitates the deformation of the connecting portion 15 and, thus, further supports the absorption of forces. The upward bending of the angle bar 23 is made easier by the elastic washer 28 positioned at the fastening screw 27, so that the angle bar 23 easier is coiled up over the faste¬ ning screw. Thus, also the deformation of the angle bar 23 contributes to the soft braking of the falling body. The assembly of the guard rail on a house roof of cor¬ rugated sheet is highly facilitated by the use of the long section bar 22 which can be provided with holes for the fastening screws 21, 27 and 29 and then inserted from the edge of the roof below a roof sheet 12 into a ridge of the sheet, so that the holes of the section bar will be posi¬ tioned just below previously made holes in the roof sheet. This fastening method enables a fast and simple assembly of the guard rail also on existing roofs. When assembling the guard rail on roofs under construction, the fastening bars are attached to the underside of the roof sheets, before the sheets are mounted on the roof. The upright post shown in Fig. 1 is intended to be attached directly to the roof sheet. While only one embodiment of the guard rail according to the invention has been shown on the drawings and descri¬ bed above, it is obvious that many modifications and alter¬ native embodiments of the guard rail are possible within the scope of the invention. For example, the connecting portion 15 of the upright posts can be provided with bends or angles, so that the deformation is facilitated. The rail bar can then alternatively consist of a bar which does not have a cross section in the shape of an angle. The legs of the upright post can also be designed in another way, and the shorter leg can for example extend over the bar 23 in front of the leg, and said bar can also have another shape of the cross section, so that the leg is bent over the bar due to the shock load. The connecting portion 15-can have another angle of inclination in relation to the plane of the sheets of the roof than 23°, but the angle should lie in the interval 10-45°. However, it is preferable to give the connecting portion 15 such an inclination in relation to the plane of the roof that it will run substantially in parallel with the portion of a life line running from the rail bar, when the life line runs over the edge of the roof due to the fact that the person attached to the other end of the life line has slipped down from the roof. This will provide the best possible absorption of the forces in the connecting portion 15 when this portion is deformed. Other materials than aluminium and aluminium alloys can also be used, for example steel or steel alloys. However, the low coefficient of elasticity of aluminium and aluminium alloys as compared with for example steel contributes to a softer braking of a falling body. Thus, the upright posts 10 and the bars 11 and 23 can be designed in many ways. Essential for the application of the invention is only that the upright posts and possibly the bars when absorbing the shock load are deformed to such an extent, that a falling body is softly braked.

Claims: Claims 1. Guard rail for the ridge and eave of house roofs, com¬ prising at least two upright posts (10) adapted to be attached to the roof (12) at a distance from each other along the ridge or the eave (16) of the roof, and a rail bar (11) running between the posts (10), characterized in that each upright post (10) is provided with at least a portion (e. g. 13) adapted to obtain a permanent deforma¬ tion, when the guard rail is exposed to a shock load from a falling human body who is connected to the guard rail by means of a l ne. 2. Guard rail according to claim 1, in which each upright post (10) consists of a substantially U-shaped support having two legs (13,14), the free ends of which are connec¬ ted to the roof (12), and a connecting portion (15) running between the legs, the connecting portion being spaced from the plane of the roof, characterized in that at least one leg (13) is adapted to obtain a permanent deformation. 3. Guard rail according to claim 2, characterized in that both legs (13,14) are adapted to obtain a permanent defor- mation. 4. Guard rail according to claim 2 or 3, characterized in that also the connecting portion (15) running between the legs (13,14) is adapted to obtain a permanent deformation. 5. Guard rail according to any of claims 2-4, in which each upright post is mounted in the direction of the pitch, cha¬ racterized in that one leg (13) is longer than the other leg (14) and in that the longer leg (13) faces the ridge of the house roof. 6. Guard rail according to claim 5, characterized in that the rail bar (11) consists of an angle bar (17,18) attached to the longer leg (13) of the post (10) at the upper por¬ tion of the post, one angle portion (18) of the angle bar running over the upper portion of the post. 7. Guard rail according to claim 6, characterized in that the connecting portion (15) of the upright post (10) is substantially straight and in that the angle portion (18) running over the post abuts the connecting portion (15) of the post. 8. Guard rail according to claim 6 or 7, characterized in that the one angle portion (18) of the rail bar (11) extends so far over the upright post that the angle portion (18) of the rail bar during the shock load will be bent downwards abutting against the connecting portion (15) bet- ween the legs (13,14) of the post, so that the connecting portion is deformed. 9. Guard rail according to claim 5, characterized in that the shorter leg (14) of the upright post faces the eave (16) of the roof and is connected to the roof (12) by means of an angle bar (23) which runs in parallel with and spaced from the eave of the roof, one angle portion (25) of the angle bar (23) running along the roof facing the eave and the other angle portion (24) being turned up from the roof and having substantially the same height as the shorter leg (14) of the upright post. 10. Guard rail according to any of the preceding claims, characterized in that each upright post (10) is attached to the roof (12) by means of a section bar (22) positioned under the roof, said bar having a length longer than the distance between the fastening points of the upright post and the free end of the longer leg (13) of the post as well as the angle portion (25) running along the roof being attached to said bar.

Inventors: JOHANSSON BERNT, KARLSSON LENNART, NILSSON MICHAEL, JOHANSSON, BERNT, KARLSSON, LENNART, NILSSON, MICHAEL
Applicants: GRAENGES ALUMINIUM AB, GRAENGES ALUMINIUM AKTIEBOLAG
Application year: 1985
Main classification: E04D13
IPC codes: E04D13, E04G21