Machine for sealing containers by applying a covering film
A system for feeding containers on conveyor consisting of a feeder conveyer and an accumulator conveyor in which the speed of the accumulator conveyor is controlled to meter the distribution of containers to a processing station, such as a sealing unit.
1. Machine for feeding containers to be processed by a processing unit, which comprises an accumulation conveyor ( 3 ), located upstream of the processing unit and driven by a first motor means ( 8 ), and a feeder conveyor ( 4 ), which feeds containers to the accumulation conveyor ( 3 ) and is driven by a second motor means ( 13 ), wherein the machine further comprises: a first sensor ( 5 ) adjacent the feeder conveyor ( 4 ), for detecting, a container ( 1 ); and a control unit, which controls the first motor means ( 8 ) such that a desired gap ( 11 ) is created between two adjacent containers ( 1 ) on the accumulation conveyor ( 3 ), and that the speed of the accumulation conveyor ( 3 ) and of the feeder conveyor ( 4 ) are equal during at least a partial handing over of the container ( 1 ) from the feeder conveyor ( 4 ) to the accumulation conveyor ( 3 ).
2. Machine according to claim 1 , wherein the machine further comprises a second sensor ( 10 ), upstream of the first sensor, which detects the distance ( 12 ) between two containers on the feeder conveyor ( 4 ).
3. Machine according to claim 2 , wherein the second sensor ( 10 ) is connected to the control unit, which reduces the speed of the feeder conveyor ( 4 ), if the distance ( 12 ) between two containers on the feeder conveyor ( 4 ) is significantly smaller than a minimum gap needed for the handover of a container as the container approaches the accumulation conveyor.
4. Machine according to claim 1 , wherein the motor means ( 8 , 13 ) are servo motors.
5. Machine according to claim 1 , wherein the feeder conveyor ( 4 ) operates at continuous or random speed.
6. A machine according to claim 1 , wherein the first sensor ( 5 ) is in an end-zone ( 6 ) of the feeder conveyor ( 4 ), to detect a front edge ( 7 ), of the container ( 1 ).
7. A machine according to claim 6 , further comprising a detection means ( 9 ) to detect the speed of the feeder conveyor ( 4 ), wherein the first sensor ( 5 ) and the detection means ( 9 ) are connected to the control unit, which controls the first motor means ( 8 ).