WO2005017289A1 - Method for making door opening for electrical equipment in thin walled poles - Google Patents

Abstract

The invention relates to a method for making openings necessary for allowing installation devices in a post having a thin casing without running the risk of causing ruptures. The invention includes forming an elongated opening, at each end defined by an edge shaped like an arch of a circle or otherwise gently curves edge and elongated sides having inwardly bent edges.

Description

Description

The invention relates to a method for making an opening adapted to receive electrical apparatuses necessary and used at post used for street and road lighting.

Today the problems relating to making openings for the purposes mentioned in thin walled posts has resulted in preventing the wide use of such posts. An opening arranged at a thin walled post extending along the casing of same, causes structural problems. Such an opening forms a weakening, sometimes even causes breaking off the post as a result of rather small loads. As at result of this it normally is preferred to attach a separate apparatus box on the outside of the post casing and to let the cables enter the inside through' an opening at the bottom end oft the post secured in foundation.

The object of this invention is to bring about a new method for making and shaping openings at thin walled post without risking a non-wanted weakening. The purpose is also directed at as far as possible avoiding shapes, which might cause ruptures or stability weakening.

Besides the above, by the method according to the invention an opening, as a direct result of the design of the opening, material portions for the mounting or electrical apparatuses are created. Such portion are formed by inwardly bent material portions along longitudinal sides of the opening.

The invention will below be explained more closely with references to the attached drawing.

On the drawing

Fig. 1 shows a section of a post jacket having an initial cut or punched aperture,

Fig. 2 shows the jacket in the axial or longitudinal direction,

Fig. 3 shows how the longitudinal side portions at the opening have been bent inwardly,

Fig. 4 shows the jacket axially or longitudinally and the inwardly bent portions

Fig. 5 shows the jacket in the same way as in Fig. 3 but after an alternative bending process, and

Fig. 6 shows a section of the alternative bending.

The casing 1 to be provided with an opening, in the example shown, is octagonal, but could naturally be circular or have any other shape. Figure 1 illustrates how two apertures are made remote from each other and joined by a slot 3. The holes and the slot may be prepared in many ways, e.g. by sawing or cutting, say laser cutting, punching or the like.

In step two illustrated in Figs 3 and 4, the material portions 3 along each side of the slot 3 have been bent inwardly so that the bending edge will extend essentially along the tangents between the sides of the two holes 2.

In alternative embodiments, not shown, the end portions of the opening may be elliptic or formed by a straight line between two quadrants of a circle.

In all cases it is so that after the bending according to Figures 2 and 3 the longitudinal sides of the opening run essentially tangentially between the curved end lines.

Figs. 5 and 6 illustrate an alternative where for the purpose of stiffening the circular or curved ends portions of the aperture besides the inwardly bending of the long sides 4' the curved end portions have also been inwardly punched so that a collar 5 is formed. Said collars will join the longitudinal inwardly bent portions 4'.

Thanks to the new method for making the openings the risk for brakes and weakening is essentially eliminated.

The invention is naturally not restricted to the embodiments described and shown and may be varied within the scope defined by the claims attached hereto.

Claims

Claims Method for making an opening for installation of and making available electrical connecting means, fuses and/or the like at a hollow post for lightning or the like, which opening is situated in mantle or jacket of the post or pole, which opening may be closed by means of a lid, characterised by the steps of making, by means of an appropriate tool, shape an opening in the post jacket or mantle (1) made opening, elongated in the axial direction of the pole, in such a way that the ends remote from each other will be defined by curved lines

(2), the ends of which essentially tangentially pass over into axially oriented lateral edges (4).

Method according to claim 1 , characteri zed in shaping the mutually remote end edges of the opening as an arc of a circle, wherein the axial or longitudinal side and edges essentially tangentially join the curved ends.

3. Method according to claim 1, characterized in shaping the end portions axially remote from each other as curved lines, which both contact the axial side lines are also joined by crosswise arranged lines.

4. Method according to claims 1, 2 or 3, characteri zed by the steps of by using a cutting and punching method, arrange in the pole mantle or jacket (1) remote from holes (2), remote from each other, and a slot like opening (3) connecting the two holes and having a transverse with smaller that that of the holes, and by deforming the material portions (4) along the slot like opening (3) inwardly, in order to shape inwardly directed material portions forming elongated edges (4') tangentially adjoining the end openings.

5. Method according to claim 4, characteri zed by utilising the inwardly pressed edges separated by the axial opening as fastening means for apparatuses or the like.

Method according to claim 5, characterized by arranging the slot (3) cutting through the material portion between the axially remote openings along a middle line at said material portion.

7. Method according to claim 6, characterized by simultaneously with the inwardly bending of the slatted material portion between the circular openings also bend the edges of said openings inwardly.