The present invention relates to an anchoring device for anchoring or holding of a plurality of different objects in a base, such as in the ground. { The invention is applicable on anchoring of a plurality of different kinds of objects in a base, such as in the t _* ground, for instance, but as the invention has been created in connection with certain works for anchoring of posts in the ground it will, for simplicity, be disclosed in the following essentially with reference to such a use, however without being restricted to only that field of use.

SE-C 87 01535-0 discloses an arrangement in posts, adapted to be set in the ground, wherein the post comprises two parts relatively movable in their axial direction, and a device which is expansible transversely of the post, adapted to be actuated for expansion upon relative movement between the parts for the pupose of anchoring the post in the ground. One of the parts forms the actual post in the shape of a rod, whereas the other part is formed by a tube surrounding the rod. The expansible device comprises a sleeve which is arranged around the rod and which is provid¬ ed with cuts which extend longitudinally along a portion of the sleeve from one end thereof towards the other end there¬ of. The sleeve is adapted to be supported by the rod in at least one direction along the geometrical axis of the rod. The tube is adapted, with one end thereof, to actuate the sleeve at the end thereof which is remote from the end wherefrom the cuts extend, viz. in order to cause the sleeve portions disposed between the cuts to move radially outward¬ ly. Further, the device according to that patent specifica¬ tion comprises protruding, winglike members to engage with the ground adjacent to the ground surface or immediately beneath the same to stabilize the post against transverse « forces.

The characterizing feature of the device according to the above mentioned patent specification is that the wing¬ like members are secured to the tube adjacent to the upper end thereof in order to stabilize the tube, whereby the tube

in its turn is adapted to stabilize the rod, which is held therein with small play, as the post, composed of the rod and the tube, is arranged in the ground.

A special feature of the device according to the above mentioned specification is that the wing-like members are oriented vertically and between themselves form an angle of about 90 degrees, and in that the wing-like members have uppermost edges parallel to planes that are perpendicular to the axis of the tube, and lowermost edges which extend upwardly and obliquely outwardly from the tube.

The just described anchoring device for posts has many advantages and has per se come to a rather widespread use. However, it has been found that the anchoring device in question has also certain drawbacks and limitations.

Thus, the previously known anchoring device is too one- sidedly directed to anchoring of posts in ground, for which reason no universal utilization is possible.

Further, the previously known anchoring device needs special pressing tools for the ultimate mounting.

In as much as, with the previously known anchoring device, in order to achieve the expansion, the entire inner rod i pulled upwardly while the surrounding tube is held back, an inevitable result is that a piece of the inner rod will protrude upwardly from the ground surface after the expansion. This may be felt as a considerable disadvantage, and, in many cases, it prohibits a "preparatory" mounting of the ground anchorings, i.e. a mounting of only the ground anchors, which are left essentially hidden, until they are actually used for their intended purpose, such as for ground anchored mounting of posts, leighter buildings etc.

Further, it should be mentioned that the previously known anchoring device, after possible damages, normally has to be replaced in its entirety, which in many cases may turn out to be both cumbersome and costly. SUMMARY OP THE INVENTION

The object of the present invention has been to remedy the above mentioned drawbacks and limitations, and, thus, to provide an anchoring device which is very universally use-

ful, and which, in a very simple manner, may be installed in advance in an entirely or essentially hidden way, and which may be ultimately mounted by means of ordinary, conventional tools.

Further, the present invention aims at providing an anchoring device, which minimizes the resultant harmful effects on the same by damages against it or against the object which has been anchored by means of the anchoring device, and which permits a simple reparation or a simple replacement after such damages.

With an anchoring device, particularly in the shape of an elongated post, intended to be put into the ground, which post comprises two axially relatively movable parts and a transversally expansible portion adapted to be actuated for expansion upon relative movement between the parts for the purpose of anchoring the post in the ground, and wherein one part forms the actual post in the shape of a rod having an outermost end and an innermost end, whereas the other part consists of a tube, surrounding the rod and having an outer¬ most end and an innermost end, and wherein the expansible portion comprises a radially expansible anchoring element, e.g. in the shape of a sleeve, surrounding the rod and having cuts which extend along a part of the sleeve, from one end thereof in direction towards the other end, which sleeve is adapted to rest against the rod in at least one direction along the geometrical axis of the post, whereas the tube is adapted, with its inner end, to actuate the sleeve at the end thereof, from where the cuts start, so as to expand the sleeve portions between the cuts radially outwardly, the above mentioned objects are achieved, accord¬ ing to the present invention, in that the anchoring device is designed in such a manner,

that the rod and the tube are dimensioned longitudinal¬ ly so that the outermost end of the rod, upon the axial relative movement of the rod and the tube for radial expansion of the anchoring elements, is in flush with or slightly inwardly of the outer end of the tube,

that the outermost end of the rod is adapted for lock¬ ing engagement with a fastener means, preferably pro¬ vided with an inner thread for threadedly engagement with a screw, and

in that there between the fastener means and the outer¬ most end of the rod is insertable an abutment member to lock the rod and the tube against axial relative move¬ ments, as the fastener means engages lockingly with the rod.

According to the invention it is preferred that the rod, at the outermost end thereof, is provided with an inner thread for threaded engagement with a screw, acting as a fastener means, whereby the rod preferably, at the outermost end thereof, has affixed thereto, as by welding, a sleeve with an inner thread.

Further, according to the invention, it is preferred that the fastener element is in the shape of an element which is yielding, preferably breakable, by exceeding of a predetermined load, particularly in the shape of screw with a head made of nylon or the like.

Further, it is also preferred according to the inven¬ tion, that the locking elment is designed as an adaptor, viz. in that it is provided with holding means, e.g. in the shape of a tubular post holder, a ring shaped fastening eye bolt or the like, and in that the locking means has, on the under surface thereof, a guide tube which fits with a small play around the uppermost end of the tube, wherein the connection between the under surface of the locking means and the guide tube preferably is easily breakable at exceed¬ ing of a predetermined load.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the accompanying drawings a preferred embodiment of the anchoring device according to the present invention, picked as an example, will be disclosed in the following.

Figure 1 illustrates diagramatically and partly in section an anchoring device according to the invention with the individual details thereof separated from each other;

Figure 2 illustrates very diagramatically a traffic sign post which has been mounted by means of a ground ancho¬ ring means according to the present invention;

Figure 3 shows the traffic sign post in figure 2 in a position which it may assume when it has been hit by e.g. a vehicle;

Figure 4 shows, partly in axial section, an anchoring device according to the present invention during a first step of its installation;

Figure 5 shows, similarly in axial section, the anchor¬ ing means in figure 4 after a radial expansion of its ancho¬ ring elements.

DETAILLED DECRIPTION OF A PREFERRED EMBODIMENT

As is known per se the anchoring device according to the present invention consists of two elongated relatively axially movable parts, viz. a rod, generally denoted 10, and a tube, generally denoted 11, surrounding the rod. On the lowermost end of the rod 10 there are aranged one or more anchoring elements 10A, which are adapted to be expanded radially outwardly for anchoring of the anchoring device in the ground. The design of the anchoring elements 10A and the manner in which they are radially expanded belongs to the prior art and therefore they need no further explanation in the present context. It should only be mentioned that the expansion is brought about by a forced axial movement of the rod 10 and the tube 11 relative to each other.

The rod 10, which may be formed from any desired simple rod steel has at its uppermost end a tubular bushing 12, affixed as by welding in a welded joint 13, which bushing is provided with a suitable inner thread 14. The inner thread 14 is adapted to receive a fastener 15, in this case in the shape of a nylon screw with a head, which fastener serves to lock the rod 10 and the tube 11 against axial movements in relation to each other.

Between the lowermost surface of the screw head and the uppermost end of the rod 10 and the tube 11, respectively, there is inserted a support member 16 in the shape of a cirkular plate, which also serves to lock the rod 10 and the tube 11 against relative movements axially.

On it lowermost surface the ground plate 16 has a guide tube 17 which fits snugly over the outer surface of the tube 11 and which, of course, also contributes to the stabiliza¬ tion. The guide tube 17 is affixed to the lowermost surface of the ground plate 16 in such a manner that these details may be broken or sheared off from each other comparatively easily (or by exceeding of a predetermined load) if sub¬ jected to possible damage. For the same reason the screw 15 consists of e.g. nylon or the like so that the whole ground anchoring device may yield away, e.g. if hit by a vehicle, without causing serious injuries, and also not permit that e.g. a traffic sign post is thrown away in such a manner that it causes personal injuries or damages to objects.

In the present case the ground plate 16 has, on the upper surface thereof, a tubular post holder 18, but, of course, many other types of adaptors may be used, e.g. adaptors that are provided with ring shaped affixing eyes for all kinds of stays etc.

Now, with reference had particularly to figures 4 and 5 in the drawings the anchoring device according to the invention is installed on its place in the following manner: The anchoring device, essentially comprising the rod 10 and the tube 11 is provided, at its intended outermost end, with a handling means, generally denoted 25, in the present case for convenience illustrated as consisting of a screw with a shaft 26, a diameter reduced lowermost end 27 with an outer thread and a head 28, e.g. in the shape of a conven¬ tional hexagonal head. On the shaft 26 of the screw there is loosely threaded a pressure or holding ring 29. The lower¬ most end 27 of the screw with its outer thread is screwed into the inner thread 14 in the bushing 13 at the uppermost end of the rod 10.

It hould be mentioned here that the inner thread 14 within the bushing 13 and the outer thread on the lowermost end 27 of the screw preferably are so called rope threads, viz. of the kind that may be found at the ends of drill rods, in as much as such threads are cmparatively easily made and are able to transmit heavy axial blows without "shearing" so that they become difficult to loosen.

Then, the assembly comprising the rod 10, the tube 11 and the handling means 25 is inserted into the ground. Often, the insertion may be carried out simply by pressing in the said assembly, but, of course, in many cases the insertion may be facilitated by having a predrilled hole 30 in the ground. In such a case this hole 30 has preferably only slightly greater diameter than the outer diameter of the tube 11, so that the insertion is facilitated while on the other hand the side stability of the anchoring device, i.e. transverse to the longitudinal axis, is not reduced.

The insertion of the anchoring device in the ground G, particularly in the hole 30 is performed under a simultane¬ ous pressure against the end of the rod 10 and the end of the tube 11, the last mentioned through the pressure ring 29 that movably surrounds the rod 10. In this way the rod 10 and the tube 11 will move downwardly simultaneously and with the anchoring elements 10A disposed along the rod 10 or in any case directed esentially axially upwardly, as is shown in figure 4.

When the anchoring device has been inserted into the ground G in the just described manner an axial relative movement between the rod 10 and the tube 11 is brought about, viz. by pulling the handle means 25 axially upwardly while simultaneously holding back the pressure ring 29. Thereby, the anchoring elements 10A that are secured to the lowermost end of the rod 10 will abut against the lowermost end of the immovable tube 11, so that the anchoring elements 10A are expanded radially to the position as shown in figure 5.

Normally, no special arrangements are required to bring about the radial expansion of the anchoring elements 10A by

means of the lowermost end of the immovable tube 11, in as much as the tube end may be suitably bevelled to bring about the expansion, or may the anchoring elements 10B be bevelled in the manner shown as an example in the drawing. However, for certain applications it may be advantageous to dispose on the rod 11, at the uppermost end of the tube 10, an expansion ring 31, e.g. of nylon, which ring may have a suitably bevelled end surface 32 to facilitate the radial expansion of the anchoring elements 10A at the axial rela¬ tive movement between the rod 10 and the tube 11.

It should be mentioned that the hole 30 in the ground G, at least at the uppermost end thereof, may have such a diameter, that it very well can receive the guide tube 17 of the adaptor, figure 1.

In practise, lengths of the anchoring device of 1000, 1350 and 2000 mm and outer diameters of 34, 70 or 90 mm have been found advantageous. For many anchoring jobs in street grounds etc. it has been found advantageous to predrill holes 30 to a depth of about 420 mm, which, when the inner¬ most rod 10 has been pulled upwardly 50 mm to bring about the above described radial expansion of the anchoring ele¬ ments 10A, results in an anchoring depth of about 370 mm. In most cases, such a depth is entirely sufficient while the said drilling depth of about 420 mm at the same time is small enough to ensure, that electric cable etc. are not drilled through, which according to set standards should be disposed at a depth of at least 450 mm.

Finally, it should be noted that the invention is by no means limited to the above described embodiments, picked as exe ples, but that the invention encompasses each and every embodiment that falls within the scope of the appended claims.