WO1997039212A1

WO1997039212A1 - Device and method for repairing of poles

Info

Publication number: WO1997039212A1
Application number: PCT/SE1997/000567
Authority: WO
Inventors: Sven Bertil Erling Svensson; Bo Ingemar Johansson
Original assignee: Lunds Energi Ab
Priority date: 1996-04-18
Filing date: 1997-04-04
Publication date: 1997-10-23
Also published as: EP0894174B1; AU2654897A; NO984799D0; SE9601472D0; EP0894174A1; DK0894174T3; SE9601472L; NO309735B1; DE69722607D1; SE504494C2; ATE242389T1; NO984799L

Abstract

A device and a method for repairing of posts, in particular lamp posts, in which the lamp post (1) is cut off in the area of the damaged portion, which is then removed from the two parts (2, 7) of the post. Subsequently, the post parts (2, 7) are jointed by means of a jointing device comprising a jointing pipe (8) exhibiting a longitudinal slit (9), which pipe is made of an elastically deformable and resilient material. When being inserted into the post parts (2, 7), the jointing pipe is squeezed together, and the squeezing ceases after the insertion into the post parts in order for the jointing pipe to spring back elastically. Subsequently, the post parts are pushed together essentially end to end so as to form a stable joint between the two parts of the post.

Description

DEVICE AND METHOD FOR REPAIRING OF POLES

The present invention relates to a device for repairing damaged poles or posts, in particular lamp posts, and to a method for repairing such posts. Such damage can for example be the result of corrosion. Every year a considerable number of lamp posts have to be replaced because of ferrous corrosion. This ferrous corrosion is most serious in the soil band on the post and is to a large extent caused by urinating dogs. Lamp posts are usually cast-in-situ or erected in a cast foun- dation under ground which, in the case of the lower edge rusting away, makes it impossible to remove the whole post in a reasonable period of time and at a reasonable cost.

Usually, the technique described in SE-C-500 645 is used for such repairs. According to this document, the old, cut-off post is to be provided with a filling and a centring part resting on the filling. Consequently, the old, cut-off post functions as an erection foundation for the new lamp post, which has a smaller diameter and which is inserted into the old post. The drawback of the such a device is that the repairs are expensive and complicated, since the old post has to be hauled away and replaced by a new one. In addition, the cables inside the post have to be jointed or changed, since the service opening on new posts usually is located higher up than on old ones. SE-B-339 552 discloses a clamp device for jointing post sections. A plurality of slits have been made in the tubular device from the opposite ends of the joint¬ ing pipe, the inner ends of the slits overlapping along part of the extent of the jointing pipe. However, in this case, too, it is a matter of replacing the old post with a new post with a smaller diameter.

Another device for repairing of posts is describ¬ ed in US-A-1 870 771, in which two posts are jointed by means of a slit sleeve, which has been inserted into the post parts, which have been pushed together. In this device, the jointing pipe is expanded with the aid of a wedge in the slit. In order to achieve the desired sta¬ bility, the sleeve is then welded on inside the post parts, and the slit is welded together. The use of such a device for repairing lamp posts means that welding sets have to be brought to the site when lamp posts are being repaired. Consequently, the repairs become complicated and time-consuming because of the welding, among other things.

Considerable cost savings with respect to materials as well as labour could be achieved if the repairs of these kinds of posts could be made less expensive and more efficient. Naturally, however, the necessary stabi- lity and durability must be preserved in the repaired post.

One object of the present invention is thus to pro¬ vide a device which is simple and time-efficient for repairing lamp posts but which still provides the neces- sary stability and durability for the repaired post.

A further object of the invention is to provide a device which makes it possible to use the old lamp post and thereby makes the repairs less expensive, with re¬ spect to both materials and labour. In addition, it is an object of the present inven¬ tion to provide a device which makes it possible to use existing cables when repairing lamp posts.

Another object of the invention is to provide a method for repairing lamp posts. These and other objects, which will be seen from the description below, have now been achieved by a device and a method according to claims 1 and 6. Preferred embodi¬ ments of the invention are stated in the subclaims 2-5 and 7. According to one aspect of the invention, the lamp post is cut off in the area of the damaged portion, which is then removed from the two remaining parts of the post. The post parts are then jointed by means of a jointing device. This device comprises a jointing pipe exhibiting a longitudinal slit, which pipe is made of elastically deformable material. When being inserted into the post parts the jointing pipe is squeezed together, and the squeezing ceases after the insertion into the post parts in order make the jointing pipe spring back elastically. Subsequently, the post parts are pushed together essen¬ tially end to end. In this way, a stable joint is formed between the two parts of the post.

A device for jointing of pipes by means of a joint¬ ing pipe is described in GB-A-2 054 077. However, this invention relates to pipes of various kinds, such as tent poles, and solves a completely different type of problem. In this case, a pipe made of hard plastic is rolled up in a press and is then inserted into a ring made of steel, after which the ends of the plastic pipe are inserted into the opposite pipe ends until these hit against the ring. The drawback of such a solution is that the clamp- ing of the jointing pipe cannot be done in situ and re¬ quires expensive equipment. In addition, the frictional forces between the plastic pipe and the jointed pipes will not be as great as those required in the present invention, since the steel ring prevents the plastic pipe from expanding to the extent necessary. Consequently, such an invention does not solve the problems which the present invention intends to solve.

The invention will be described in more detail below with reference to the accompanying drawing, which sche a- tically illustrates a preferred embodiment, and in which Fig. 1 shows a cross-section of the lamp post after it has been cut off, and

Fig. 2 shows a cross-section of the lamp post after it has been jointed. Fig 1 shows a post 1, in particular a lamp post, which is damaged by corrosion in the area of the soil band J, and which has been cut off at ground level so that a first post part 2 still remains in a foundation 3. Prior to the post being cut off, a service opening 4 has been opened and a number of cables 5 have been loosened from a post insert 6 inside the lamp post 1. When the rust-damaged portion has been cut-off, a cut off post part 7 is used for the repairs by being jointed with the first post part 2 with the aid of a jointing device.

The jointing device comprises a jointing pipe 8 of elastically deformable and resilient material, preferably a cold-rolled steel pipe. Other examples of suitable ma¬ terials are hot-dipped rolled steel and stainless steel. For repairing smaller posts, it is also conceivable that the jointing pipe is made of e.g. aluminium or glass fibre. The jointing pipe 8 has a slit 9 extending along the whole extent of the jointing pipe 8. In the jointing pipe's 8 unloaded state, the width of the slit 9 in the circumference of the jointing pipe 8 is sufficiently large for the jointing pipe 8 to have a slightly smaller outer diameter than the inner diameter of the post 1 when the slit has been closed by the squeezing of the joint¬ ing pipe 8 circumferentially. In the jointing pipe's 8 unloaded state, the outer diameter of the jointing pipe should exceed the inner diameter of the post 1. The jointing pipe 8 is kept temporarily squeezed together with the aid of at least one clamping means 10, e.g. a hose clamp, so as to make it possible to insert the jointing pipe 8 into the post parts 2, 7.

When the jointing pipe 8 has been squeezed together with the aid of the clamping means 10, the ends of the jointing pipe 8 are inserted into the two adjoining post parts 2, 7. Subsequently, the squeezing ceases by virtue of the clamping means 10 being removed so that the joint¬ ing pipe springs back elastically in order to abut against the inside of the post parts 2, 7. Finally, the post parts 2, 7 are brought together essentially end to end. In Fig. 2, the post 1 is shown after the post parts 2, 7 have been brought together. The clamping means 10 has been removed, the jointing pipe 8 has sprung back elastically, and, thus, the two parts 2, 7 of the post are reassembled. The joint 11, which has been formed between the two parts 2, 7 of the lamp post 1 and which is bridged by the jointing pipe 8, is preferably covered with a standard cover 12 of elastomeric material for sealing purposes. Trials have taken place with standard posts of the type which is presently used in parks and which has an inner diameter of about 100 mm and an outer diameter of about 108 mm. These trials have shown that a suitable jointing pipe for this type of posts has an outer dia- meter of about 102 mm in the unloaded state of the joint¬ ing pipe and a longitudinal slit with a width of about 15 mm when the wall thickness of the jointing pipe is about 3.5 mm.

Further measuring has shown that it is suitable for the slit jointing pipe in its unloaded state to have an outer diameter which is about 2-3 mm greater than the inner diameter of the post and that the width of the slit in the circumference of the jointing pipe is about 14-16 mm.

Claims

1. A device for repairing a damaged post (1 ), in particular a lamp post, comprising a jointing pipe (8), which has a longitudinal slit ( 9 ) along its whole extent and which, after the post having been cut into two post parts (2, 7) and after the removal of the damaged por¬ tion, is intended to be inserted into the post (1) for bridging a joint (11) between the post parts, c h a r ¬ a c t e r i s e d in that the jointing pipe (8) consists of an elastically deformable and resilient material and has a larger outer diameter than the inner diameter of the post (1), that the width of the slit ( 9 ) in the circumference of the jointing pipe (8) in the jointing pipe's (8) unloaded state is sufficiently large for the outer diameter of the jointing pipe (8) to be smaller than the inner diameter of the post when the slit ( 9 ) has been closed by means of squeezing together the jointing pipe (8) circumferentially, and that the device comprises a clamping means (10) for temporary squeezing together of the jointing pipe (8) and closing of the slit (9) before the insertion of the jointing pipe (8) into the damaged post (1).

2. A device according to claim 1, wherein the outer diameter of the jointing pipe (8) exceeds the inner dia¬ meter of the post (1) by about 2-3 mm and the width of the slit (9) in the circumference of the jointing pipe

(8) is about 14-16 mm in the jointing pipe's (8) unloaded state.

3. A device according to claim 1, wherein the outer diameter of the jointing pipe (8) exceeds the inner dia- meter of the post (1) by about 2 mm and the width of the slit in the circumference of the jointing pipe (8) is about 15 mm in the jointing pipe's unloaded state.

4. A device according to any one of claims 1-3, wherein the jointing pipe (8) is a steel pipe, preferably a cold-rolled steel pipe.

5. A device according to any one of claims 1-4, which comprises a cover (12) made of elastomeric material for sealing of the joint (11) between the post parts (2, 7) jointed by means of the jointing pipe (8).

6. A method for repairing a damaged post ( 1 ), in particular a lamp post, comprising the following steps: cutting of the damaged post ( 1 ) into two post parts (2, 7) and removal of its damaged portion, insertion of a jointing pipe (8) with a longitudinal slit (9) into the post parts (2,7), and bringing together of the post parts (2, 7), c h a r a c t e r i s e d in that a pipe, which consists of an elastically deformable and resilient material and has an outer diameter which exceeds the inner diameter of the post ( 1 ) , is employed as a jointing pipe (8), that the slit jointing pipe (8) is squeezed together cir¬ cumferentially to an extent sufficient for insertion into the two adjoining post parts (2, 7) of the post (1), and that the squeezing together of the jointing pipe (8) ceases for elastic spring-back of the jointing pipe ( 8 ) prior to the bringing together of the post parts (2, 7).

7. A method according to claim 5, wherein the joint (11) between the two post parts (2, 7) is covered with a cover (12).