being disassembled as is shown in fig8 in their assembled condition the edge portions 88 and 888 abut onto one another as is clearly shown in fig4 and 5 and comprise locking means designed for providing a stable coupling of the two half shells more specifically the bayonet coupling or attachment comprises a plurality of teeth 99 formed on the annular edge portion 88 adapted to engage with respective seats 110 formed on the annular edge portion 888 of the other half shell the half uprights 44 444 moreover are each provided with respective holes 11 111 for housing a braking device therein in this connection it should be pointed out that the rotary movement can also be prevented by other locking means such as screws or bolts the rotary annular element 3 is preferably constituted by an inner ring element made of a self lubricating material 103 on which is mounted a rubber bearing rim 203 including a plurality of teeth 233 for fixing a rubber annular element 303 the rubber bearing rim 203 is designed for supporting a rubber annular element 303 forming a tread portion of the rotary annular element or more specifically wheel 3 the wheel construction according to the invention can be assembled in a very simple and quick manner as is clearly shown in fig6 8 the wheel construction is assembled by.