Conveyor system with automatic load transfer

A conveyor system having an overhead conveyor including a carrier track, a plurality of carriers each including at least one trolley mounted on the carrier track, a power track positioned adjacent to the carrier track, and driven power means carrier by the power track for moving the carriers along the carrier track in a forward direction, the improvement wherein:

• each carrier is provided with a load supporting structure suspended from said trolley and having at least one downwardly extending portion adapted to be engageable with and disengageable from a load in response to relative vertical movement between the carrier and the load;
• a second conveyor is arranged in longitudinally parallel relation with and is spaced vertically below said overhead conveyor at a load transfer zone, means for driving said second conveyor in synchronism with said power means of said overhead conveyor, said overhead and second conveyors having a vertical spacing which changes through said transfer zone between a greater spacing at which a load is engaged and supported by said downwardly extending portion of a carrier and a lesser spacing at which said downwardly extending portion of a carrier is disengaged from such load and such load is supported by said second conveyor;
• and
• carrier positioning means is operative at said lesser vertical spacing for moving a carrier laterally between a clearance position and an aligned position relative to a load, said carrier positioning means comprising
• at least one carrier track portion extending obliquely relative to said second conveyor and adapted to support said trolley of each carrier,
• transfer power means associated with said obliquely extending carrier track portion for moving each carrier therealong,
• and means for driving said transfer power means in synchronism with said power means and at a speed proportional to the speed of said second conveyor and to the obliquity between said track portion and said second conveyor whereby relative movement between a carrier on said track portion and a load on said second conveyor is substantially confined to lateral movement.

A conveyor system having an overhead conveyor, and a second conveyor, portions of said overhead and second conveyors being arranged in longitudinally parallel vertically spaced relationships at a load transfer zone, the improvement wherein:

• said overhead conveyor includes a carrier track, a plurality of carriers mounted on the carrier track, each carrier being provided with a load supporting structure having at least one downwardly extending portion adapted to be engageable with and disengageable from a load in respone to relative vertical movement between the carrier and the load, and driven power means for moving the carriers along the power track in a forward direction;
• said second conveyor comprises means adapted to provide a support for each load, and means for driving said second conveyor in synchronism with said overhead conveyor at a speed substantially equal to the speed at which said carriers are moved along the carrier track by said driven power means, said overhead and second conveyors having a vertical spacing which changes through said transfer zone between a greater spacing at which a load is engaged and supported by said downwardly extending portion of a carrier and a lesser spacing at which said downwardly extending portion of a carrier is disengaged from such load and such load is supported by said second conveyor;
• and
• positioning means is provided at said lesser spacing in one of said overhead and second conveyors for relatively laterally moving a load and a carrier between a clearance position and an aligned position, said positioning means comprising
• a transfer portion of said one conveyor extending obliquely to said longitudinally parallel portions, transfer power means associated with said obliquely extending transfer portion for moving each load therealong,
• and means for synchronously driving said transfer power means and at a speed proportional to the speed of the other of said overhead and second conveyors and to the obliquity of said transfer portion whereby a load on said transfer portion is moved in the forward direction at a speed substantially equal to the speed of the other of said overhead and second conveyors.