Patent attributes
A device comprising a planar element with a first wheel supported about a first rotary axis, a handle support, and a folding joint connecting the handle support to the planar element pivotal about a first pivotal axis such that in an operating state the handle support is aligned to a planar element at an angle, is provided. At least one second wheel is supported about a second rotary axis, at the distal end of the planar element. The second wheel is pivotal about a second pivotal axis and coupled to the handle support via a mechanism which converts a pivotal motion of the handle support about the first pivotal axis into a pivotal axis of the second wheel about the second pivotal axis such that the second rotary motion of the second wheel shows in the idle state a greater angle to the planar element than in the operating state.