Live roller circle for power shovels and the like

Claim 1

An improved live roller circle structure for a large heavy-duty machine, such as a power shovel, which is subject to large eccentric loads wherein said machine includes a lower frame, an upper frame rotatably mounted on said lower frame by said live roller circle, wherein said roller circle structure includes a lower rail mounted on said lower frame, said lower rail having a width which exceeds 5% of the mean diameter of said roller circle, a roller cage structure, a plurality of pins mounted on said roller cage structure, rollers mounted on said pins and supported in rolling contact with said lower rail and an upper rail mounted on said upper frame and supported on said rollers, said upper rail having a width substantially equal to that of said lower rail and wherein said roller circle is arranged with respect to said upper and lower frames and said eccentric load is of a value as to cause the center of gravity of the machine to travel beyond the diameter of said roller circle under normal operating conditions, said improved live roller circle further comprising: a set of at least two cylindrical rollers mounted on each pin of said roller cage structure of said live roller circle.