FIELD OF THE INVENTION

The invention relates to an attachment member of a bridge repair scaffold as well as an arrangement for attaching the repair scaffold to the deck of a bridge.

BACKGROUND OF THE INVENTION

WO2008132277 presents a scaffold arrangement suitable for repair work on the deck of a bridge. The arrangement is composed of a group of scaffold stands to be installed on the deck of the bridge, which are supported against the bridge by bolting the stand to the upper surface of the deck of the bridge and, thereafter, by supporting the stand with a pivotable support member against the lower surface of the deck of the bridge.

One problem of scaffold stands according to the arrangement of prior art is the strength required of the bolting. With short bolts, to be attached to the deck of the bridge and located as close to each other as possible, adequate strength can be achieved for some intended purposes, for example, for supporting workers moving on a scaffold. However, if to the scaffold stands are attached heavy machine tools, such as, for example, water blasting hardware, or concrete cast- ing moulds carrying heavy concrete castings, the strength of a bolt attachment according to prior art may no longer be adequate. Problems may be created especially, when the concrete of the bridge to be repaired has become brittle.

Thus, what is needed is an attachment arrangement, with which the scaffold stands of the bridge repair scaffold can be attached to the deck of a bridge such that with the attachment is achieved the strength required for the task. The levels of strength required from the attachment may, depending on the task, be more than one. It should be possible to safely perform the attachment work of the scaffold stand from the deck of the bridge and from the scaffold to be installed. OBJECT OF THE INVENTION

One object of the invention is an attachment member and arrangement for safely attaching a scaffold stand to be used in the repair of the bridge to the deck of a bridge during the time of repair work.

BRIEF DESCRIPTION OF THE INVENTION The first aspect of the invention is an attachment member for attaching a scaffold stand to the deck of a bridge. The scaffold stand to be attached can be arranged to be supported, for example, from at least two support points against the upper side of the deck of the bridge, of which support points on the upper side of the deck at least one support point is arranged to receive compressive force from the deck of the bridge and at least one support point is arranged to receive pulling force from the attachment member attached to the deck of the bridge. The attachment member is characterized in that it is fitted to be detachably attached to the deck of the bridge with at least two attachment means and comprises at least one attachment means for attaching the attachment member to the support point of the scaffold stand receiving pulling force.

The scaffold stand to be attached can also be arranged to be supported from at least one support point against the underside of the deck of the bridge. The support point of the scaffold stand receiving compressive force from the deck of the bridge is preferably arranged outside the area of the attachment member.

In one embodiment of the invention, the attachment member is further fitted to be attached to the deck of the bridge with at least one bolt going through the deck of the bridge.

In one embodiment of the invention, the attachment member comprises attachment means for detachably attaching a drilling machine to the attachment mem- ber. The second aspect of the invention is an arrangement comprising an attachment member and scaffold stand according to the first aspect.

The third aspect of the invention is an arrangement comprising an attachment member of the scaffold stand and a drilling machine, therein detachably attached with attachment means, for drilling a hole through the deck of a bridge.

The fourth aspect of the invention is a method for detachably attaching a scaffold stand of the invention to the deck of a bridge.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the invention is described in more detail with reference to the accompanying figures, of which

Figs. 1a-1e show the use of an attachment member according to one embodiment of the invention when installing a scaffold stand to the deck of a bridge, and

Fig. 2 shows an attachment member and a scaffold stand according to one embodiment of the invention from another viewing angle.

Fig. 1a shows an attachment member 102 to be detachably attached to the deck 130 of a bridge. The member can be a sheet made of a suitable material, for example, steel. The shape of the sheet can be selected as suitable for the intended use. The shape can be, for example, a quadrangle, other polygon, ellipse or circle. On the edges of the sheet, there are holes, through which can be passed bolts 103, with which the attachment member is bolted to the deck of the bridge. The attachment member 102 has also, preferably in its middle, a hole 11 1 , through which the attachment member can be attached to the deck of the bridge with greater strength by using a bolt installed in a hole drilled through the deck of the bridge. The attachment member 102 is further fitted to be combined with connection means, for example, one or more bolts 104 for detachably attaching the scaffold stand to the member. The surface area of the sheet and/or the number of connection means 103 and their distance from each other can all be selected according to how great a load it is desired to have the attachment structure formed by means of the attachment member 102 bear. By increasing the distance of the connection means 103 from each other, the strength of the attachment can be improved. A bridge deck that is brittle on its surface may require the use of an attachment member 102 (and possibly more connection means 103) having a greater surface area than a bridge deck of stronger structure.

Fig. 1 b shows the making of a hole drilled though the deck of a bridge using the aid of an attachment member 102 and connection means fitted to the upper surface of the attachment member, for example, attachment bolts 103. To the bolts is detachably attached a drilling machine 140, which moves, for example, on its rails 141. As the drilling machine 140 is moved downwards, the bit 142 of the machine drills via the hole 1 11 a hole 1 12 (shown in Fig. 1 c) through the deck of the bridge. Because the drilling machine is attached firmly with the connection means, for example, with attachment bolts 103, to the attachment member, drilling the hole through the deck of the bridge succeeds reliably and accurately. In one embodiment, the drilling machine can, further or alternatively, be attached also to the attachment means 104 and/or to a bushing 109.

Fig. 1 c shows a step, in which a scaffold stand 101 is lowered to the deck of the bridge on top of the connection means 104 of an attachment member 102. The stand can now be attached to the deck of the bridge by attaching it to the attachment member 102 with the connection means 104, for example, with bolts and nuts.

Fig. 1d shows a scaffold stand 101 as attached with connection means 104 to the deck of a bridge/ Further, the scaffold stand is supported against the deck of the bridge by a support plate 120 attached to the stand with a bolt 106, onto which support plate is focused the compressive force created by the mass of the scaffold stand between the scaffold stand and the deck of the bridge. The bolt 106 and support plate 120 are preferably arranged outside the area of the at- tachment member 102, thus the attachment member 102 cannot typically receive compressive force. A scaffold stand 101 attached to the deck of a bridge in the manner presented in the figure will already withstand enough load so that the stand installation work can be completed. To the scaffold stand can, in this step, be installed, for example, walkways (not shown in the figure) as a passageway for workers. By means of the walkways, the support member 108 underneath the bridge deck receiving compressive and/or pulling force can be set in place to support the attachment of the scaffold stand. Similarly, the nut 107 can be installed on the bolt 105 from the walkway. Because the support member 108 can, in some cases, for example, when the scaffold stand is loaded with adequately great force, receive instead of compressive force also pulling force, the support member 108 is typically bolted onto the lower surface of the deck of the bridge.

Above the hole in the middle of the attachment member 102 is permanently fitted a bushing 109. The bushing extends above the upper surface of the attachment plate 1 10 of the scaffold stand 101 itself. That is, there is also a hole in the plate 110 of the stand, from which the bushing extends above the plate 1 10. The hole of the plate 1 10, from which the bushing extends above the plate, is somewhat larger than the bushing so that the bushing fits through it.

The bushing 109 serves to guide the scaffold stand, when it is installed in place. In this way, an attempt is made to keep the attachment bolts 104 from getting so easily damaged. The bushing extends above the attachment plate 1 10 also for the reason that when bolting through the deck is performed, the nut of the bolt rests up against the bushing and transfers force to the attachment plate of the deck. In one embodiment, the bushing can also function as the attachment point for the drilling machine in a drilling situation, preferably when drilling actual at- tachment holes for the bolts 103 and/or a through attachment hole 112 for the bolt 105.

Fig. 1 e shows a scaffold stand 101 as attached to the deck of a bridge by means of both the attachment member 102 and the connection means 103 and 104 and the attachment means travelling through the deck of the bridge, for example, a bolt 105 and nut 107. Now, the attachment of the scaffold stand to the deck of the bridge is adequately strong for attaching to the scaffold stands even heavy machines, for example, machines weighing several hundred kilos or for using casting moulds carrying heavy concrete.

Fig. 2 shows an arrangement according to one embodiment of the invention from another viewing angle. The support plate 120, onto which is directed the com- pressive force from the scaffold stand, is attached to the attachment plate 1 10 of the scaffold stand by adjustable attachment means, for example, by a bolt 106. Because the attachment member 102 and the support plate 120 are separate, it is possible to attach the scaffold stand 101 also to a more uneven bridge deck. By means of the adjustment screws in an attachment member 102 and a support plate 103 that are separate, it is possible, regardless of unevenness of the deck, to adjust the entire stand and, at the same time, the station of the entire line network as uniform, i.e. the stands 101 can be brought as well as possible into the same position in both vertical and horizontal directions.

In one embodiment, the support plate 120 can also be bolted to the deck of the bridge, for example, to assure that the stand will remain in place even in difficult wind conditions, in which the wind load may attempt to lift the scaffold stand upwards.

In the preferred embodiment shown in this figure, the attachment bolts 104 and 105 are essentially in the same line in relation to each other and the attachment bolt 105 is fitted essentially to the centre of the attachment member 102. With this arrangement, the strength of the structure can be improved.

Because the attachment member 102 to be attached to the deck is "massive", for example, several tens of kilos in mass, and it gets tensile stress alone, the degree of evenness of the deck does not influence the durability of the attachment member 102. If there were to be compression on the attachment member 102, unevennesses of the deck would cause point-like loads on those parts of the plate, which would be against the concrete, whereas those parts of the plate, which due to the unevenness of the deck were not against the concrete, would not bear any load. Correspondingly, a support plate 120 receiving compressive force, which is relatively small in surface area, is capable of distributing load efficiently to the deck of the bridge.

It is obvious to the person skilled in the art that the exemplary embodiments presented above are, for the purpose of illustrating the description, relatively simple in structure and function. Following the model presented in this patent applica- tion, it is possible to construct various and very complicated solutions, which will utilize the inventive idea presented in this patent application.