Patent ID: 8011307

Claim:
A retractable bearing device ( 10 a - c ) for a loading bed ( 1 ) to facilitate at least one of displacement and positioning of heavy loads ( 2 ) in a transfer plane (T), extending parallel to the loading bed ( 1 ), the bearing device comprising: a profile ( 20 a - c ) equipped with balls ( 30 ) and displacement means ( 40 a - c ) for displacing the balls ( 30 ) between a working position, in which the balls ( 30 ) project from the profile to support the load ( 2 ), and a resting position, in which the balls ( 30 ) are retracted within the profile and do not support the load ( 2 ), each ball ( 30 ) being attached to a housing ( 21 a - c ) in the profile ( 20 a - c ) by a guide and sealing ring ( 50 ) having a spherical cavity ( 53 ) that captively mates with an exterior surface of the ball ( 30 ) and covering an area that extends from either side of a median transverse plane of the ball ( 30 ) to captively retain and maintain the respective ball ( 30 ) in position relative to the housing ( 21 a - c ), and the guide and sealing ring ( 50 ) comprises a means for forming a seal between both the ball ( 30 ) and the housing ( 21 a - c ) and moving along with the ball ( 30 ) when the ball ( 30 ) moves to and fro between the working position and the resting position.