Patent ID: 7228803

Claim:
An inclined guide wheel for engaging with and being guided along a guide rail, the inclined guide rail comprising: a plate ( 26 ) having a projecting peripheral edge ( 27 ); and a wheel rim ( 25 ) secured to the plate ( 26 ), and the wheel rim ( 25 ) having a replaceable perimeter covering ( 28 ) for normally engaging with a travel path ( 8 , 9 ) of a guide rail ( 4 ) as the inclined guide wheel travels along a guide rail without any lateral force being applied to the guide wheel; wherein the projecting peripheral edge ( 27 ) has a recess ( 30 ) on an inwardly facing surface thereof such that when a lateral force is applied to the guide wheel, the recess ( 30 ) engages with a projection of the guide rail and causes the covering ( 28 ) of the wheel rim ( 25 ) to interrupt contact with the travel path ( 8 or 9 ) of the guide rail ( 4 ) and to be spaced therefrom so as to avoid premature deterioration of the covering ( 28 ).