Patent ID: 7455492
Filing Date: 2008-11-25
Classification: B66C

Abstract:
1. A multiple trolley container crane comprising: (a) at least upper and lower trolley tracks extending substantially parallel to each other; b) at least one support surface disposed below said lower trolley tracks; c) a plurality of trolleys for traveling on the trolley tracks, each trolley having laterally deployable and retractable running wheels, a driving device, and an integrated lifting system for supporting the trolley on or beside the trolley tracks and enabling the trolley to pass from the lower trolley track to the upper trolley track and vice versa such that when at least one of said plurality of trolleys moves from said lower trolley tracks to said upper trolley tracks said at least one trolley is positioned beside said upper trolley tracks, and wherein said at least one of said plurality of trolleys moves from said upper trolley tracks to said lower trolley tracks, said at least one trolley is positioned beside said lower trolley tracks wherein said integrated lifting system is configured to lift a trolley above at least one of said upper tracks and said lower tracks by contacting said at least one support surface; wherein the integrated lifting system for each respective trolley is selected from a group comprising vertically oriented cylinders or telescoping cylinders and racks with gear wheels or spokes.