The object of the invention is a base structure as defined in the preamble of claim 1.

The solution according to the invention is well suited to be used e.g. as a base of traffic signs or as a base of some other corresponding device or product provided with a verti ^¬ cal post, e.g. as a base of the vertical stem of an outdoor lamp. Likewise, the arrangement according to the invention can be used, for instance, as a base for fence posts.

A problem in installing a traffic sign, a lamp or corresponding provided with a post-like stem into the ground is often that the installation must be performed sufficiently deep so that the installation would be durable, and in public facili ^¬ ties it should also withstand vandalism. Digging deep in the installation phase is slow and can damage e.g. underground cables or pipes.

A solution, inter alia, wherein a lattice-type platform is dug to a certain depth under the ground, has been developed to solve the problem. There is, however, no need to dig the lattice base to as deep down as the bottom end of a vertical post should be dug without the lattice base. A vertical post is fixed to the lattice base e.g. by welding. A problem in this solution is that the lattice base cannot necessarily be brought into the exact horizontal plane, in which case get ^¬ ting the vertical post into a vertical attitude is more dif- ficult. In addition, welding fixing at the installation site is awkward and slow to perform.

The aim of the present invention is to eliminate the afore ^¬ mentioned drawbacks and to achieve as advantageous and simple a base structure as possible by the aid of which the vertical post of a traffic sign, of a lamp or corresponding can be installed into the ground easily, quickly and firmly. Another aim of the invention is to achieve an adjustable base structure, on which the vertical post can always easily be adjusted- into the vertical position irrespective of in what position the lattice platform is to be installed. The base structure according to the invention is characterized by what is disclosed in the characterization part of claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims. One advantage of the base structure according to the invention is that it is advantageous, simple and operationally reliable in its structure and it is also easy to adjust so that the vertical post of a traffic sign, of a luminaire or corresponding can always be installed in a vertical position. Another advantage is the rapidity of the installation, because the vertical post or its extension piece does not need to be welded to the lattice platform. An advantage is also the secure fixing in its position. The vertical post locks firmly into its position and stays straight well.

In the following, the invention will be described in more detail by the aid of two examples of its embodiment with reference to the attached drawings, wherein Fig. 1 presents an oblique top view of one base structure according to the invention, installed on top of a lattice-type platform,

Fig. 2 presents a top view of a locking means of a base structure,

Fig. 3 presents a side view of the base structure according to Fig. 1, installed on top of a lattice- type platform,

Fig. 4 presents a partially sectioned side view of a base structure according to Fig. 1, installed on top of a lattice-type platform, Fig. 5 presents a partially sectioned side view of a second base structure according to the invention, installed on top of a lattice-type platform,

Fig. 6 presents a side view of one tightening means of the base structure according to Fig. 5,

Fig. 7 presents a side view of a second base structure according to the invention, installed on top of a lattice-type platform,

Fig. 8 presents a top view of a second locking means of a base structure according to the invention,

Fig. 9 presents a top view of one plate-like auxiliary locking means of a base structure,

Fig. 10 presents a side of view of a third base structure according to the invention, and

Fig. 11 presents a top view of the base structure according to Fig. 10.

Fig. 1 presents one base structure according to the invention, installed on top of a lattice-type platform 1. The lattice-type platform 1 is e.g. an essentially plate-like platform made of metal comprising a plurality of essentially rectangular apertures lb in parallel rows, which apertures are separated by walls la and extend through the platform 1. The base structure according to the invention can be directly fixed to the top surface of the platform 1.

The base structure according to the invention comprises at least a fixing piece 2 provided with a sleeve-like or pinlike stem 5, a locking means 3 of the fixing piece, and tightening means 4, with which the locking means 3 is firmly tightened on top of the spherical bottom part 7 of the fixing piece 2. On the top end of the stem 5, e.g. glued inside the stem, is a round vial 2a, by the aid of which the fixing piece 2 can be accurately placed in a vertical position in the installation phase. The vial could as well be detached, which vial is placed onto the top end of the stem 5 only in the installation phase and taken out after the fixing piece 2 is tightened into its final position. In this case the vial can also be used in other installations.

The vertical post of a traffic sign, of a luminaire or corre- sponding can be fixed by its bottom end to the fixing piece 2 and locked to it in different ways. One method is presented in the figures, in which the stem 5 of the fixing piece 2, which stem is to be installed in a vertical position, comprises a locking hole 8 for locking the vertical post into its position.

Fig. 2 presents one locking means 3 of a base structure according to the invention as viewed from above. The locking means 3 comprises a plate-like frame part comprising at least for its part a flat bottom surface, in the center of which frame part is a through hole 3a. The hole 3a is surrounded by a circular collar 3b rising upwards from the top surface of the locking means 3, the bottom surface of which collar is curved such that it can be fitted on top of the spherical bottom part 7 of the fixing piece 2. In addition, the corners of the frame part of the locking means 3 comprise holes 3c for the lead-ins of tightening means 4, such as of screws.

Figs. 3-5 present a base structure according to the invention as viewed from the side and fixed on top of a lattice-type platform 1. For illustrative purposes Figs. 4 and 5 are presented partly sectioned. The fixing piece 2 of a base structure comprises at least an essentially spherical bottom part 7 functioning as an adjustment means and fitting means, from the top part of which bottom part a spherical calotte of a suitable size is cut off and onto the surface of which spherical calotte an essentially cylindrical collar part 6 is fixed. An essentially cylindrical stem part 5, the outer diameter of which is smaller than the outer diameter of the collar part 6, forms an extension of the collar part 6 and is placed centrally with respect to the collar part. In this way a collar, on which the vertical post of a traffic sign, of a lamp or corresponding can rest when the vertical post is placed on top of the stem part 5, remains in the joining point of the stem part 5 and the collar part 6. The bottom part 7 of the fixing piece 2 of the base structure functions as a spherical adjustment and fitting means. The diameter of the bottom part 7 is dimensioned such that the bottom edge of the bottom part 7 sinks suitably partly into the top part of the aperture lb of the lattice-type platform 1 when the spherical bottom part 7 is placed on top of the aperture lb. The fixing piece 2 is locked to one of the apertures lb of the lattice-type platform 1 by the aid of the locking means 3 and the tightening means 4. The diameter of the center hole 3a of the locking means 3 on the bottom sur- face of the locking means 3 is greater than on the top surface of the collar 3b extending to above the locking means 3. Additionally, the diameter of the center hole 3a of the locking means 3 on the bottom surface of the locking means 3 is smaller than the diameter of the spherical bottom part 7 of the fixing piece 2. In this way the locking means 3 can be placed on top of the spherical bottom part 7 of the fixing piece 2, in which case a part of the collar 3b remains compressing the top surface of the spherical bottom part 7. The fixing piece 2 is tightened into its position by the aid of the locking means 3 and the tightening means 4 such that after the tightening the stem part 5 of the fixing means 2 is in a desired position, suitably e.g. in a vertical position irrespective of in what position the lattice-type platform 1 is. In Fig. 5 e.g. the lattice-type platform 1 is in an inclined attitude, but owing to the structure of the spherical bottom part 7 of the fixing piece 2 and the structure of the locking means 3 the stem part 5 of the fixing piece 2 can be turned into a vertical position. The adjustment can be made in all horizontal directions. The bottom end of the tightening means 4 comprises e.g. a screw thread, which is fitted to the tapped holes of a plate functioning as a stopper element 9, in which case the spherical bottom part 7 is compressed between the locking means 3 and the lattice-type platform 1 by the aid of the locking means 3, the tightening means 4 and the stopper element 9, which stopper element 9 is on the other side of the lattice- type platform 1 to the locking means 3. Fig. 6 presents a second advantageous solution for the structure of the tightening means 4. The top end of the tightening means 4 does not now comprise a fixed nut head, such as the tightening means 4 presented in the previous figures, but instead the first end, i.e. the top part, of the stem of the tightening means 4 comprises a screw thread 4a, to which the tightening nut 4c is fitted. The second end, i.e. the bottom part, of the stem of the tightening means 4 presented by Fig. 6 is bent into a hook-shaped structure, in which the tip of the hook 4c points essentially backwards towards the first end of the tightening means 4. Owing to this hook-shaped structure, the stopper element 9 is not needed and the lock ^¬ ing means 3 can be fixed and tightened directly from above to on top of the spherical bottom part 7 of the fixing piece 2 by threading the tightening means 4 from above through the apertures lb of the lattice-type platform 1 to below the walls la and by performing the final anchoring and tightening by the aid of nuts 4c.

Fig. 7 presents a second base structure according to the invention, installed on top of a lattice-type platform 1. The lattice-type platform 1 is e.g. an essentially similar platform made of metal as the lattice-type platform presented in Fig. 1. The base structure according to the invention can be directly fixed to the top surface of the platform 1.

The second base structure according to the invention comprises at least a fixing piece 2 provided with a sleeve-like or pin-like stem 5, a locking means 3 of the fixing piece, a plate-like auxiliary locking means 10 on the surface of the platform, and tightening means 4, with which the locking means 3 is firmly tightened on top of the spherical bottom part 7 of the fixing piece 2. At the top end of the stem 5 is a space for a vial, which vial can be fixed or detached. By the aid of the vial the fixing piece 2 can be placed accurately in a vertical position in the installation phase. The vertical post of a traffic sign, of a park luminaire or courtyard luminaire or of some other luminaire or corresponding can be fixed by its bottom end to the fixing piece 2 and locked to it in different ways. One method is presented in the figures, in which the stem 5 of the fixing piece 2, which stem is to be installed in a vertical position, comprises a locking hole 8 for locking the vertical post into its position. The fixing piece 2 and its spherical bottom part 7 are advantageously provided with a through hole, which enables an easy and tidy lead-in of an electri- cal wire in luminaires, inter alia.

Fig. 8 presents a second locking means 3 of a base structure according to the invention as viewed from above. The locking means 3 comprises a plate-like frame part comprising at least for its part a flat top surface and bottom surface, in the center of which frame part is a through hole 3a. The rim of the hole 3a is not an even circular rim, but instead the rim comprises alternately narrow-tipped and castellated protrusions 3d extending towards the center point of the hole and round-bottomed areas 3e extending away from the center point of the hole. The protrusions 3d can have a sharp tip, but advantageously their tips are leveled, in which case they have a short surface in the direction of the inner rim of the hole 3a. The areas 3e can also be of other shapes than round- bottomed, but a round-bottomed shape is very durable. In addition, the corners of the frame part of the locking means 3 comprise holes 3c for the lead-ins of tightening means 4, such as of screws.

Fig. 9 presents an auxiliary locking means 10 to be placed below the spherical bottom part 7 of the fixing piece 2, which auxiliary locking means improves locking stability. The auxiliary locking means 10 with its center hole 3a is essentially similar in its shape to the locking means 3, but the hole 3a in the center is smaller than the corresponding hole 3a in the center of the locking means 3.

To improve the locking the spherical bottom part 7 of the fixing piece 2 is provided with a plurality of narrow grooves 7a passing around the surface of the bottom part, which grooves are placed on the surface of the bottom part essentially densely and concentrically in relation to the vertical axis of the fixing piece 2. When locking the fixing piece 2 into its position the protrusions 3d of the center hole 3a of the locking means 3 push essentially into the grooves 7a on the top surface of the bottom part 7 and in the same way the protrusions 3d of the auxiliary locking means 10 correspondingly push into the grooves on the bottom surface of the bottom part 7, in which case the locking becomes very durable.

Figs. 10 and 11 present a movable concrete base 11, the top surface of which comprises a larger vertical center hole 12 and the bottom of the hole 12 comprises further a smaller vertical center hole 11, which extends through the base 11 to the bottom surface of the base. In addition, the base comprises fixing holes 14, which extend in the vertical direction e.g. through the whole base 11. The diameter of the larger center hole 12 is suitably greater than the diameter of the spherical bottom part 7 of the fixing piece 2 and the depth of the center hole 12 is suitably smaller than the height of the spherical bottom part 7. In this case the fixing piece 2 can be easily placed by its bottom part 7 into the hole 12 and can be firmly tightened into its posi ^¬ tion by the aid of the locking means 3 and the tightening means 4. The auxiliary locking means 10 can be used, if necessary, at the bottom of the hole 12.

It is obvious to the person skilled in the art that the invention is not limited to the example described above, but that it may be varied within the scope of the claims presented below. Thus, for example, the implementation of a lattice-type platform and a base structure can also be different than what is described above.

It is obvious to the person skilled in the art, for example, that the spherical bottom part of the fixing part does not necessarily need to be spherical from the top side, but instead it is sufficient when only the bottom side is essentially spherical. In this case the top surface of the bottom part, the locking means and the tightening means are different in their structure than what is presented above.

It is also obvious to the person skilled in the art that instead of the spherical bottom part of the fixing part, the bottom part can be implemented e.g. by the aid of another type of spherical joint that can be tightened.