The present invention relates to an anchorage arrange¬ ment for e.g. anchoring of scaffolds at walls or the like, which arrangement consists of a screw socket and an anchor bolt.

At the mounting of scaffolds the scaffold must be an- chored in a safe way. This is done by securing the scaffold at a large number of points by anchor bolts screwed into the wall at which the scaffold is mounted. Today this is normally done by first drilling a hole in the wall, and then hammering a plug into said hole, whereafter the anchor bolt is screwed in manually in the the wall in order to anchor the scaffold. It is both a tiresome and time consuming work to manually screw in the anchor bolts.

The background of the invention is the large strains, specially in the shoulders, experienced by scaffolders at the up to now used manual method to screw in anchor bolts. It has showed in practice that the installers, due to being pressed for time, often are careless with the important anchoring, as it is both time consuming and tiresome to screw in anchor bolts in the prescribed number. Of course this is unaccept- able from the view point of security.

The use of the anchorage according to the invention is not limited to scaffolds but can be used anywhere when some kind of anchorage arrangement is needed. Examples of other fields of use are railings, fences, wire carriers, fire- ladders and lifting eye bolts for e.g. rocks.

Thus, the object of the present invention is to facili¬ tate to screw in the anchor bolts by making it possible to use an ordinary drilling machine for the actual screwing in. This object is meet with an anchorage arrangement ac- cording to the enclosed claims.

When using the arrangement according to the invention a socket is placed in a drill chuck in the normal way. The socket has an inner cruciformed recess in which the eye of the anchor bolt fits. Furthermore, the anchor bolt is fur- nished with a cone which has a corresponding form to chamfers on the recess within the socket. The cone and chamfers partly acts to guide the application of the socket on the anchor bolt and partly to hinder the stem of the anchor bolt from striking against the inner of the socket during the screwing operation.

At schaffold mounting the normal distance from the plank platform on which one stands at the mounting of the anchor bolts and the hole in which the anchor bolt is to be screwed in is about 2 m, which gives a cumbersome working posture with large strain on particularly the shoulder part at the presently used method of manually screwing in anchor bolts. This work is facilitated by the invention by which one can use the some drilling machine for both screwing in of the anchor bolts and to drill the holes in the wall in which the anchor bolts are screwed in. By using a drilling machine the bolts are screwed in with a greater force, which expands the plugs in the wall more and gives a stronger anchoring. Due to the cruciformed recess of the socket with chamfering and the cone of the anchor bolt it goes fast and easy to screw in the bolts without the bolt stem striking against the socket. This becomes more important if the scaffold, as e.g. often happens at additional insulation, is mounted at a relative large dis¬ tance from the walls whereby long anchor bolts must be used. Without the chamfers and the cone it would be very difficult to screw in the anchor bolts without them striking against the socket. Furthermore it is a clear risk that the anchor bolts will strike so much that they affect the hole in the wall.

When sheeting the scaffold, i.e. covering it with plas- tics, almost twice as many anchor bolts must be used due to the surface exposed to the wind.

The invention is more closely explained below by means of embodiments shown in the enclosed drawings, in which:

Fig. 1 is a sectional view of the socket taken along the line I-I in Fig. 2;

Fig. 2 is an end view showing the inner of the socket;

Fig. 3 is a side view of one anchor bolt;

Figs. 4a-4h are side views of different anchor bolts;

Figs. 5 and 6 are sectional views of the socket furnished with magnetic rods and rubber coatings, respective¬ ly;

Fig. 7 is a sectional view of the socket furnished with rubber coatings in accordance with Fig. 6;

Fig. 8 is a sectional view showing a detail of one type of expander; and

Fig. 9 is a plan view of a socket intended for the an¬ chor bolt according to Fig. 4e.

The present invention thus refers to a socket and anchor bolt arrangement for use in anchoring of scaffolds at walls or the like.

The arrangement consists of a socket 1 with a pin 2 for connection with e.g. a drill chuck and an anchor bolt 5. The interior of the socket 1 has a cruciformed recess 3, with chamfers 4. The anchor bolt 5 has an eye 6 and an extension in form of a cone 7 between the eye 6 and the bolt stem 8. Furthermore the bolt 5 is threaded 9 so it can be screwed into the wall.

The cone 7 may be an integrated or welded part of the anchor bolt 5, or a loose cone screwed onto the bolt. The cone 7 may be made of aluminium, steel or the like. The screwable cone is furnished with an interior thread corre¬ sponding to the thread of the bolt 5, the bolt suitably being threaded all the way up to the eye 6. By such an arrangement the position of the cone 7 on the bolt 5 may be altered as required.

When using the invention one may in a normal way drill a number of holes in the wall which then are furnished with plugs. Then the socket is placed in e.g. a drill chuck (not shown) by means of the inlet pin 2. When the anchor bolts 5 then are to be screwed into the drilled and plugged holes in the building wall the eye 6 of the bolt 5 is placed in the recess 3, whereby the cone 7 cooperated with the chamfers 4 of the recess 3 in order to give a fast, reliable and stable contact between the anchor bolt 5 and the socket 1. The screw part 9 of the anchor bolt 5 is adapted to the

actual use. It is thereby possible to use e.g. self-drilling bolts 5 for wood, concrete or lightweight concrete etc., with or without expander 11. Then there is no need for any pre- drilling. Examples of different anchor bolts 5 with different kinds of threads 9 are shown in the Figs. 4a to 4h.

The chamfers 4 are largest at the edge of the socket and decrease inwardly of the socket 1 at the same angle as shown by the cone 7 on the anchor bolt 5. In this way a large con¬ tact surface is obtained between the socket 1 and the bolt 5 which functions as guide for the application of the socket on the bolt besides from stabilizing the screwing.

Besides from acting to guide the socket at the screwing in of the bolt the cone 7 furthermore acts stiffening for the bolt 5 itself. Furthermore, the cone 7 may assist in stiffen- ing of the attachment of the anchor bolt in the wall ^\' by abut¬ ting the wall.

A further advantage with the invention is that for an¬ chor bolts 5 with not integrated cones 7, the cone may be post tensioned against the wall in order to further strength- en the anchorage, making the plug in the wall expanding bet¬ ter, which gives a stronger anchorage. Furthermore it is pos¬ sible, if necessary, to make the cone 7 bigger by e.g. design it with a straight part 14 after the cone. In order to facil¬ itate the post tensioning the cone 7, as well as the cham- fers, may be hexagonal or octagonal or the straight, addi¬ tional part 14 above may have the form of a nut. The cone is very important at lateral displacement or pressure from above for suspended scaffolding.

It is suitable to arrange some kind of attachment in the socket 1, i.e. means which keep the bolt 5 in place even if the socket 1 is directed downwardly. There are many conceiv¬ able ways to arrange this keeping. The preferred way at pre¬ sent is to, in accordance with Fig. 5, integrate magnetic rods 10 in the socket, which magnets 10 are dimensioned in order to securely hold the anchor bolts 5 within the socket 1.

In stead of magnets 10 the channels 3 of the socket 1 may be lined with raw rubber 12 in accordance with Figs. 6 and 7 whereby the friction between the eye 6 and the rubber 11 is enough to keep the bolt 5 in place. This is particular-

ly suitable when using hammer drills .

In order to be able to replace worn rubber coatings 12 the socket 1 may consist of two parts, with the two parts assembled by means of threads (not shown) . The partition of the socket can hereby be arranged on any side of the rubber elements 12. When the rubber elements 12 are to be replaced the socket is thus parted by screwing the two part from each other, the worn rubber coatings 12 are taken off and new are put in, whereafter the socket 1 once again is screwed togeth- er and then is ready for use.

As a further alternative to the attachment for the bolt 5 in the socket 1 it is conceivable to use spring biased clips in the socket 1.

The bolts 5a and 5b according to the Figs. 4a and 4b, respectively, are a self-drilling steel bolt and wood bolt, respectively.

The bolt according to Fig. 4c, which is intended for concrete is self-drilling 13c and has an expander lie. When this bolt 5c has been screwed in by means of the socket 1 it is post-tensioned by the cone 7c being screwed in whereby the expander lie expands by being pushed onto the conically ex¬ panded part 15c behind the drill 13c. Such a bolt 5c gives a reliable anchorage and get its strength from several coopera¬ ting factors such as the pressure of the expander lie against the walls of the drilled hole and the abutment of the cone 7c against the wall in which the bolt 5c has been screwed in. It is possible to re-use this bolt 5c with the expander lie. When herewith the bolt 5c is to be loosened the cone 7c is first loosened, then the bolt 5c is striked inwardly a dis- tance corresponding to the expansion of the expander lie, whereby the expander lie is compressed by springs arranged in the expander lie. In order to support this movement a pin may be arranged affecting the springs. The outer surface of the expander lie may furthermore have the shape of a drill in order to remove material from the drilled hole at the screw¬ ing in. Also, this surface form gives the expander lie a stronger abutment against the drilled hole. The expander lie can be made of many different materials such as steel, alumi¬ num, plastics or rubber. If rubber is used it is suitable to arrange small spikes on the outer surface, in order to remove

material from the drilled hole.

The bolt 5d according to Fig. 4d is a self-drilling 13d bolt 5d intended for lightweight concrete and is furnished with an expander lid. The bolt 5e according to Fig. 4e is a wood bolt with open eye 6e. By the special form of this eye 6e a special socket 1\' must be used, which corresponds to the socket 1 above except that in stead of the cruciformed inner recess 3 the socket 1\' has a recess 3\' adapted to the form of the eye 6e. In the example shown the socket 1\' is furthermore fur¬ nished with magnetic rods 10.

In Fig. 4f a bolt 5f is shown, which is self-drilling 13f and is intended for lightweight concrete.

The bolt 5g according to Fig.4g is a self-drilling 13g bolt 5g with expander llg intended for concrete. The outer surface of the expander llg has a form which corresponds to a drill in order to remove material from the drilled hole dur¬ ing the screwing in.

In Fig. 4h a bolt 5h is shown which is self-drilling 13h and has a divisible expander llh with an outer "drill shaped" surface.

A further form of expander 11, which e.g. could be used with the bolt 5h according to Fig. 4h, is shown in section in Fig. 8. As is evident from the figure the inner surface of the expander 11 is furnished with a wedge-shaped thread 15 adapted to the thread of the bolt 5. This expander is used as follows. When the bolt 5 has been drilled to the bottom with the cone 7, or its extension 14, abutting the wall the cone 7 is held with a wrench, then the bolt 5 is screwed out by means of e.g. a screwdriver introduced through the eye 6. Thus expanding the expander by means of the wedge-shape of the thread 15. The more the bolt is screwed out the more the expander 11 tightens. When the bolt 5 then is screwed back in the expander 11 retracts due to the thread 15. This makes it possible to then withdraw the bolt 5.

The different bolts 5a-h in the figures are shown as examples of how the invention may be used in different ways in practice, and persons skilled in the art realize that there are many different possibilites of variation concerning dimension, selection of material, type of thread etc.