Today there are many toy building sets of this type on the market that comprise toy building elements and vehi- cles that can be interconnected to form various struc- tures. The vehicles are configured either as actual vehi- cles-cars, trucks, trains, etc.-or merely as a car- riage bottom with wheels ; in all cases they are provided with coupling means for interconnecting with other toy building elements. Typically the coupling means consist of coupling studs on the top faces of the toy building element as well as on the vehicles, and coupling means that are complementary therewith on the underside of the toy building elements and optionally of the vehicles.

In the prior art toy building sets of this type the vehi- cles are provided with circular wheels that are each con- centrically journalled on a shaft such that, to a very wide extent, the vehicles resemble"authentic"vehicles.

US-A-3 835 583 discloses a toy element that simulates a caterpillar or a worm. The toy building element is split and each of the two parts is provided with circular wheels. In the junction between the two parts a through-

going shaft is provided on which two elliptical wheels are excentrically journalled. When the toy element trav- els across a plane drive face, the elliptical wheels will cause the junction to move up and down and it thus seems as if the toy element wiggles its way across the drive face.

GB-A-2 249 735 teaches a toy car wherein the front wheels are mounted on an excentrically journalled shaft. There- fore the toy car exhibits a tilting movement when it travels across a drive face.

It is the object of the present invention to provide a toy building set comprising a vehicle that exhibits par- ticular driving features and that will, in combination with the remaining toy building elements in the toy building set, provide the user with completely novel and educating play experiences.

This is obtained by configuring the toy building set de- scribed above such that at least the one wheel has a rolling face with varying distances from the shaft on which it is journalled such that a waving movement of the vehicle is obtained when it travels across a plane drive face.

Hereby it is obtained that, apart from the option of con- structing different structures by means of the remaining toy building elements on the vehicle, the vehicle also exhibits a tilting drive movement wherein the stability of the vehicle depends on the structure or construction made on the vehicle. It is thus possible to build a low structure by which the point of gravity of the entire ve- hicle is not raised or just raised slightly, such that it

does not substantially influence the behaviour of the ve- hicle. If, on the contrary, a high or heavy structure is built, the point of gravity is raised with ensuing con- siderable influence on the behaviour of the vehicle.

With a toy building set according to the invention, the user is thus able to test the influence of differently constructed structures on the behaviour of the vehicle; eg how high a structure can be built before the vehicle topples. Thus the toy building set according to the in- vention enables the user to have novel and educating play experiences.

According to a preferred embodiment the vehicle is pro- vided with two wheels with varying distances from the shaft on which they are journalled to their respective roller faces, and the vehicle leans on the drive face with two of its wheels and with a support knob provided downwardly protruding from the vehicle body at a distance from the two wheels. Despite its simplicity-this con- struction yields a particularly interesting movement of the vehicle when it drives across a drive face.

Preferably, the wheels have a circular rolling face while simultaneously they are excentrically journalled on their respective axes. This is the most simple configuration of the wheels and additionally it imparts a very harmonious and regular movement pattern to the vehicle when it drives across a drive face.

Preferably, the coupling means of the toy building set consists of coupling studs that protrude from the body parts of the toy building elements and the vehicle body, respectively, and coupling means that are complementary

therewith provided to be upwardly protruding at least in the body part of the toy building elements. Hereby it is possible to make the toy building set according to the invention complementary with existing toy building sets.

If a loose fitting is used between the coupling studs and the coupling means that are complementary therewith, it is possible to obtain very special effects when a vehicle provided with other toy building elements tiltingly trav- els across a drive face. As it is, the stacked toy build- ing elements will constitute an instable construction that present the option of performing detours due to the movements of the vehicle. In order to further enhance the play experience, a drive means can be arranged within the vehicle body for advancing the vehicle, said drive means being in communication with a shaft on which a wheel is mounted. According to a particularly preferred embodiment the drive means is configured with a winding-up mecha- nism.

The invention will now be explained in further detail with reference to the drawing, wherein Figure 1 shows a vehicle for a toy building set according to the invention in a preferred embodiment thereof; Figure 2 shows a drive means arranged within the vehicle shown in Figure 1; and Figure 3 shows toy building elements and a vehicle for a toy building set according to the invention in combined state.

Figure 1 shows a preferred embodiment of vehicle 1 for a toy building set according to the invention. In the em- bodiment shown the vehicle 1 simulates a ladybird or some other insect or animal. The vehicle has a body 2 that is provided with a coupling means in the form of an upwardly protruding coupling stud 3. Besides, the vehicle 1 is provided with two wheels 4 and 5 that extend from the bottom of the body 2, and with a support knob 6 that is rounded and an integral part of the body 2. When the ve- hicle 1 is positioned on a support or a drive face it leans on the wheels 4,5 and the support knob 6.

In the embodiment shown the wheels 4,5 are configured as circular discs, ie they have a circular roller face, but are journalled excentrically on a shaft in the vehicle 1.

This appears most clearly from Figure 2 that shows a drive means 7 arranged within the vehicle shown in Figure 1, whereas the body 2 of the vehicle 1 is shown by dotted lines.

The drive unit 7 is preferably a so-called'pull-back' drive unit, ie a drive unit with a winding-up mechanism that can be activated by pulling the vehicle 1 rearwards across a drive face, while the wheels 4,5 are in contact there with. When the vehicle 1 is subsequently let go, the drive unit 7 will make the wheels 4,5 drive and cause the vehicle 1 to drive forwards.

As will appear most clearly from Figure 2, the wheels 4,5 are excentrically journalled on a shaft 8 that is, in a manner not shown in further detail, connected to the drive unit 7. The wheels 4,5 are journalled asymmetri- cally such that when the wheel 4 is in its lowermost po- sition the wheel 5 is in its uppermost position as shown.

Such journalling of the wheels 4,5 causes the vehicle 1 to tilt about a horizontal axis in the driving direction of the vehicle 1 when it drives on a plane drive face.

When the vehicle 1 is situated on a plane drive face it will, as mentioned, lean on the one hand on the wheels 4,5 and on the other hand on the support knob 6. Such three-point support means that not only will the vehicle tilt about a horizontal axis in its driving direction, but also to a smaller extent about a vertical axis that extends between the wheels 4,5.

The overall movement of the vehicle 1 is thus a combina- tion of a waving or tilting movement about a horizontal as well as a vertical axis with a resulting movement pat- tern that resembles a slalom course.

Once again, Figure 3 shows the vehicle 1 seen from behind with three identical toy building elements 9 built on top. Each of the toy building elements 9 comprises a body part 10, a coupling stud 11 that protrudes upwardly from the body part 10, and a downwardly oriented skirt 12 in the form of a tubular member that can receive a coupling stud 3,11.

In the embodiment shown the toy building elements 9 are configured as stacking elements, ie toy building elements where there does not exist a tight coupling between the various elements. Thus, the toy building elements 9 are able to capsize slightly relative to each other and rela- tive to the vehicle 1 when they are interconnected. This is illustrated in Figure 3 where the vehicle 1 is shown in a position where the wheel is located as far as possi- ble into the body 2, whereas the wheel 5 is as far as

possible out of the body 2. Since the vehicle 1 is ar- ranged on a plane drive face 13, the vehicle 1 and the structure built thereon will incline to the left.

When the vehicle 1 drives forwards the wheel 4 will come further out of the body 2, whereas the wheel 5 will dis- appear further into the body 2. Thus, the vehicle 1 will tilt towards the right and the built-on structure will follow. When the vehicle 1 drives across the drive face 13 the vehicle 1 along with the toy building elements 9 will tilt from side to side as indicated by the double arrow P. Since, however, the toy building elements 9 in the embodiment shown are configured as stacking elements without a tight coupling the built-up structure will be rather instable and it will therefore move in an unpre- dictable manner. This contributes to increasing the play experience while simultaneously it is an educating ex- perience to the user to observe the movements that occur.

If the toy building elements are configured with a tight coupling between their respective coupling means, stable structures can be constructed on the vehicle. Such struc- tures shift the point of gravity of the vehicle in a pre- dictable manner, and it is thus possible to experiment with differently constructed structures to see the influ- ence of various locations of the point of gravity of the vehicle on the movements of the vehicle.

In the embodiment shown the wheels 4 and 5 are positioned asymmetrically on the same shaft 8 such that the vehicle 1 tilts from side to side when it drives across a drive face. However, the wheels could also be positioned sym- metrically on the shaft whereby a tilting movement about a horizontal axis that extends transversally to the vehi-

cle could be obtained, ie a back-and-forwardly tilting movement. Of course, the wheels can be journalled in other ways to obtain a different tilting movement.

The wheels could also be configured to be non-circular, eg elliptical or polygonal with rounded corners. In case of such configurations of the wheels the journaling need not be excentrical to still obtain the tilting or waving movement when the vehicle drives across a driving face.

Finally the vehicle can be configured without a drive unit, or it can be configured with some other kind of drive unit than the one shown, eg a battery-operated mo- tor.

Other variations can be performed without therefore devi- ating from the idea of the invention.