Granted Patent B2

US 8,016,282 · App. 12/239,021 · Granted Sep 13, 2011

Abstract

Claims (72)

1. A method of singulating overlapping items, comprising:

receiving the overlapping items in a singulation device, wherein the singulation device comprises:

a first transport element configured for rotation in a first direction; and

a second transport element in opposing relation to the first transport element and forming a transport path between the first and second transport elements, wherein the second transport element is configured for rotation in a second direction opposite to the first direction such that within the transport path both the first and second transport elements will provide a frictional force in a common direction to items in the transport path;

rotating the first transport element at a first transport speed;

rotating the second transport element at a second transport speed substantially equal to the first transport speed;

conveying the overlapping items between the transport elements along the transport path;

decreasing the second transport speed to singulate the overlapping items;

decreasing the first transport speed to reduce a speed of a lead item after it is singluated; and

transporting the lead item away from the singulation device.

2. The method of claim 1 , further comprising:

increasing the first transport speed to advance a subsequent item; and

transporting the subsequent item away from the singulation device at a predetermined pitch with respect to the lead item.

3. The method of claim 2 , wherein the singulation device further comprises a plurality of sensors, comprising at least an upstream sensor and a downstream sensor, arranged along the transport path for detecting a position of respective items.

4. The method of claim 3 , wherein decreasing the second transport speed comprises:

detecting a leading edge of the lead item with respective sensors; and

decreasing the second transport speed by a predetermined amount as each sensor detects the leading edge.

5. The method of claim 4 , wherein decreasing the second transport speed further comprises stopping the second transport element on detection of the leading edge by the downstream sensor.

6. The method of claim 3 , wherein increasing the first transport speed to advance the subsequent item comprises:

detecting a position of the lead item;

detecting a position of the subsequent item;

computing a modified first transport speed based on the position of the lead item and the position of the subsequent item; and

rotating the first transport element at the modified first transport speed.

7. The method of claim 6 , wherein detecting the position of the lead item comprises measuring the position of the lead item using an encoder.

8. The method of claim 6 , wherein detecting the position of the subsequent item comprises detecting the position of the subsequent item using a sensor.

9. The method of claim 6 , wherein the modified first transport speed is computed to provide the predetermined pitch between the lead item and the subsequent item.

10. The method of claim 2 , wherein transporting the subsequent item away from the singulation device comprises receiving the subsequent item in a transport nip.

11. The method of claim 2 , further comprising increasing the second transport speed substantially simultaneously with increasing the first transport speed to advance the subsequent item.

12. The method of claim 11 , wherein the second transport speed is increased based on a position of the subsequent item.

13. The method of claim 2 , further comprising decreasing the first transport speed to reduce a speed of the subsequent item prior to transporting the subsequent item away from the singulation device.

14. The method of claim 1 , wherein decreasing the first transport speed comprises stopping the first transport element substantially simultaneously with transporting the lead item away from the singulation device.

15. The method of claim 1 , wherein transporting the lead item away from the singulation device comprises receiving the lead item in a transport nip.

16. A method of singulating overlapping items, comprising:

receiving the overlapping items in a singulation device, wherein the singulation device comprises:

a first transport element configured for rotation in a first direction; and

a second transport element in opposing relation to the first transport element and forming a transport path between the first and second transport elements, wherein the second transport element is configured for rotation in a second direction opposite to the first direction such that within the transport path both the first and second transport elements will provide a frictional force in a common direction to items in the transport path;

rotating the first transport element at a first transport speed;

rotating the second transport element at a second transport speed substantially equal to the first transport speed;

conveying the overlapping items between the transport elements along the transport path;

detecting a position of a leading edge of a lead item along the transport path;

decreasing the second transport speed based on the position of the leading edge to singulate the overlapping items;

decreasing the first transport speed to reduce a speed of the lead item after it is singulated;

transporting the lead item away from the singulation device;

increasing the first transport speed to a modified first transport speed based on the position of the lead item and a position of a subsequent item to advance the subsequent item;

decreasing the first transport speed to reduce a speed of the subsequent item; and

transporting the subsequent item away from the singulation device at a predetermined pitch with respect to the lead item.

17. The method of claim 16 , wherein the modified first transport speed is computed to provide the predetermined pitch between the lead item and the subsequent item.

18. The method of claim 16 , further comprising increasing the second transport speed based on the position of the subsequent item substantially simultaneously with increasing the first transport speed to advance the subsequent item.

19. A device for singulating overlapping items, comprising:

a singulation device for receiving the overlapping items, wherein the singulation device comprises:

a first transport element configured for rotation in a first direction; and

a second transport element in opposing relation to the first transport element and forming a transport path between the first and second transport elements, wherein the second transport element is configured for rotation in a second direction opposite to the first direction such that within the transport path both the first and second transport elements will provide a frictional force in a common direction to items in the transport path; and

a controller operatively connected to the first transport element and the second transport element, the controller configured to:

rotate the first transport element at a first transport speed;

rotate the second transport element at a second transport speed substantially equal to the first transport speed, so as to convey the overlapping items between the transport elements along the transport path;

decrease the second transport speed to singulate the overlapping items;

decrease the first transport speed to reduce a speed of a lead item after it is singulated; and

activate a transport nip to transport the lead item away from the singulation device.

20. The device of claim 19 , wherein the controller is further configured to:

increase the first transport speed to advance a subsequent item; and

activate the transport nip to transport the subsequent item away from the singulation device at a predetermined pitch with respect to the lead item.

21. The device of claim 20 , wherein the singulation device further comprises a plurality of sensors, comprising at least an upstream sensor and a downstream sensor, arranged along the transport path for detecting a position of respective items.

22. The device of claim 21 , wherein to decrease the second transport speed, the controller is configured to:

detect a leading edge of the lead item with respective sensors; and

decrease the second transport speed by a predetermined amount as each sensor detects the leading edge.

23. The device of claim 22 , wherein the controller is further configured to stop the second transport element on detection of the leading edge by the downstream sensor.

24. The device of claim 21 , wherein to increase the first transport speed to advance the subsequent item, the controller is configured to:

detect a position of the lead item;

detect a position of the subsequent item;

compute a modified first transport speed based on the position of the lead item and the position of the subsequent item; and

rotate the first transport element at the modified first transport speed.

25. The device of claim 24 , wherein the modified first transport speed is computed to provide the predetermined pitch between the lead item and the subsequent item.

Assignments (7)