Patent ID: 8365905

Claim:
A movement device, comprising: an endless belt comprising a working portion defined in a substantially horizontal working plane and a reserve portion defined in a reserve plane; a first guide wheel linearly movable in said working plane and guiding the endless belt; another first guide wheel linearly movable in said reserve plane and guiding the endless belt; two deflector members for deflecting the endless belt from the working plane to the reserve plane; drive means for driving the endless belt; and first movement means for synchronously moving the two first guide wheels in such a manner that the sum of the distances between each of the first guide wheels and the deflector members is constant; said movement device further comprising: at least one second guide wheel linearly movable in said working plane; at least one stationary u-turn member in said working plane to deflect the endless belt from said first guide wheel to said second guide wheel in said working plane; at least another second guide wheel linearly movable in said reserve plane; at least one stationary u-turn member in said reserve plane for deflecting the endless belt from said first guide wheel to said second guide wheel in said reserve plane; and at least one second movement means for the second guide wheels for moving said second guide wheels synchronously in such a manner that the sum of the distances between each of said second guide wheels and the deflector members remains constant; wherein the length of the working portion of the endless belt is capable of varying continuously and the quantity of articles that can be placed on the working portion of the belt can vary accordingly.