Collapsible support for a fairground attraction

The invention relates to a support installation for a fairground attraction, comprising a base, two pairs of masts which can be moved between a collapsed and an erected position, as well as a head that in the erected position is at the top of the masts, on which head a Ferris wheel or a swing or the like can be mounted, each mast having a base segment that is joined to the base such that it can pivot, as well as a top segment that is joined to the head, at least in the erected position, said masts each comprising several segments that are joined to one another such that they can pivot, wherein the base has a longitudinal direction and the pivot joints between the segments are oriented essentially transversely to said longitudinal direction.

Such a support installation is disclosed in US-A-3 456 943. Said prior art support installation comprises pairs of masts having lower segments which are crossed and which are pivotally connected at their point of crossing. Furthermore the masts have upper segments which are pivotally connected to the upper end of a respective lower segment. The upper ends of the upper segments are pivotally connected to each other. The pantograph-like masts thus formed can be extended upwardly to an erected position, and can be lowered to a collapsed position. In order to stabilize the masts in the extended position, braces are to be connected to the pivot connections between the segments.

This pantograph-like masts have several disadvantages. First of all, such masts have limited stability. For this reason the additional braces must be used. Furthermore said prior art masts are of a complicated structure, including sliding tracks for moving the lower ends of the lower segments towards and away from each other in the processes of erecting and collapsing the masts.

A support installation of this type is furthermore disclosed in US 6 634 952 B2. With this installation the masts of each pair in the erected position form two sides of a triangle and the base forms the third side of said triangle. The base segment of one of the masts of each pair is fixed with respect to the base, whilst the base segment of the other mast is joined to the base such that it can pivot. Said fixed base segment is relatively short, so that the associated top segment can be relatively long. However, the length of the top segment must be less than the length of the base, because otherwise this top segment would protrude with respect to the base in the collapsed position. This is highly undesirable, especially also because of the fact that the base is usually constructed as a trailer for transport by road. The length of the segments of the other mast of each pair is approximately half the length of the base. One disadvantage of this support installation is, therefore, that the height thereof is restricted in the erected position.

The object of the invention is therefore to provide a support installation which lacks these disadvantages. Said object is achieved in that each mast has two and only two segments, and in that each pair of masts in the erected position forms two sides of a triangle and the base forms the third side of said triangle.

The masts of the support installation according to the invention provide a simple, stable construction which obviates the need for additional braces. Moreover, the process of erecting and collapsing of the masts is fairly simple as a result of the pivotal movements of the lower ends of the lower segments, instead of sliding movements.

Because both base segments are joined to the base such that they can pivot, the height of the support installation can be appreciably increased. For example, both the base segment and the top segment can be approximately the same length as the base, without protruding with respect to said base in the collapsed position. By this means the height of the support installation can therefore be approximately twice that of the known support installation.

According to a first variant each base segment and each top segment is essentially the same length as the base and the top segments of both masts of each pair are joined to one another by means of a detachable coupling. In this case the height of the erected support installation is approximately twice the length of the base. The support installation can be erected while the head remains joined to the top segments of a respective pair of masts.

In a second variant each mast has a base segment that is essentially the same length as the base, as well as a top segment that has a length that is approximately equal to half the length of a base segment. In this case the top segments can be joined to one another by a permanent pivot coupling.

In the case where each mast has only two segments it suffices for stabilisation of the erected support installation to fix only the base segments with respect to the base. In an advantageous embodiment fixing takes place by means of actuators which also provide for erection of the support installation. These actuators can, for example, be constructed as hydraulic piston/cylinder devices that at one end are joined to the base and at the other end are joined to a base segment; stabilisation of the support installation can then be effected by fixing the length of said hydraulic piston/cylinder devices.

It is not necessary to use hydraulic piston/cylinder devices for stabilisation of the masts. Instead of this, stabilisation can also be obtained by means of mechanical locking means, such as between the base segments and the base.

With the support installation according to the invention the segments of each mast, in the collapsed position, can be essentially alongside or on top of one another and along or on top of the base. This is made possible in that the pivot joints between the masts and the base are oriented transversely to the longitudinal direction of the base, such as a trailer and the like. Furthermore, the pivot joints between the segments are also essentially oriented transversely to said longitudinal direction.

Reference is made to the support installation as disclosed in DE-A 21 34 415. Masts that consist of two segments are used in this known support installation. These segments are joined to one another such that they can pivot. Furthermore, the masts are joined to the base such that they can pivot, and specifically in accordance with pivot links, the axis of which is oriented in the longitudinal direction of said base. With this known support installation the masts can therefore not be alongside or on top of one another and along or on top of the base in the collapsed position. The segments can be accommodated in this position on the base only if the pivot joints were first to be dismantled for this purpose. However, such a procedure is highly laborious and in any event renders efficient and rapid construction of the support installation according to the invention impossible.

The invention will now be explained in more detail with reference to the following figures:

• Figure 1 shows a side view of one embodiment of the invention, where the support installation supports a Ferris wheel,
• Figure 2 shows a side view of an embodiment of the invention where the support installation supports a swing,
• Figure 3 shows, in side view, the various stages of erection of a first embodiment of the invention,
• Figure 4 shows, in side view, the various stages of erection of a second embodiment of the invention,
• Figure 5 shows a side view of an embodiment of the invention where the support installation is stabilised by hydraulic piston/cylinder devices.

A support installation 1 according to the invention can be seen in Figure 1. At the top of a pair of masts 2 of the support installation there is a head 3 on which a Ferris wheel 4 has been mounted such that it can rotate. The masts have a base segment 6a, 6b that is joined by means of pivot links 12a, 12b to base 5 such that it can pivot, and a top segment 7a, 7b that is joined to the head. Pivot links 13a, 13b form the link between the base segments and the top segments. It can be seen that the support installation is appreciably higher than the length of the base; as a result it is possible to construct the Ferris wheel with a diameter of almost twice the height of the support installation. The support installation can, for example, also support a swing 8, as can be seen in Figure 2.

Figure 3 shows the erection of a pair of masts according to a first embodiment of the invention. Each mast has a base segment 6a, 6b and a top segment 7a, 7b, which are essentially the same length as the base. In the collapsed position these segments are alongside one another and along the base, as shown in Figure 3a. When erecting the support installation, the base segment 6b of one of the pair of masts is first raised, see Figure 3b, until the top segment 7b of said mast can be coupled by means of a detachable coupling 11 to the top segment 7a of the other mast, see Figure 3c. The support installation can then be fully erected by raising the base segments 6a, 6b, as can be seen in Figures 3d to 3h, the top segments remaining coupled such that they can pivot.

Figure 4 shows the erection of a pair of masts according to a second embodiment of the invention. Each mast has a base segment 6a, 6b that is essentially the same length as the base 5, and a top segment 7a, 7b, the length of which is approximately equal to half that of the base segment. The top segments are joined to one another by means of a permanent pivot coupling 10. In the collapsed position the segments are alongside one another and along the base, as shown in Figure 4a. The support installation can now be erected by raising the base segments, as shown in Figures 4b to 4h.

The support installations in Figure 4 and Figure 3 can be stabilised by fixing the base segments with respect to the base; the top segments then have no further freedom of movement. Figure 5 shows one possible embodiment of such stabilisation, where fixing is effected by means of actuators 9 which also provide for erection of the support installation. These actuators can, for example, be constructed as hydraulic piston/cylinder devices which at one end are joined to the base and at the other end are joined to a base segment. Stabilisation of the support installation is then effected by fixing the length of said hydraulic piston/cylinder devices, for example by shutting off the oil supply thereto.