Unstacker for unstacking items conveyed in a bulk stream

• US 20020079194A1
• Filed: 12/26/2000
• Published: 06/27/2002
• Est. Priority Date: 12/26/2000
• Status: Active Grant

• Current Assignee: FIVES MANUFACTURING INDUSTRIES S.A
• Original Assignee: Sandvik Sorting Systems Inc.
• Inventors: Terrell, Jonathan D., Schroader, Steven Vann, Ydoate, Edward
• Granted Patent: US 6,491,154 B2
• Time in Patent Office: Days
• US Class Current: 198/461.1
• CPC Class Codes: B65G 47/31 by varying the relative speeds of the conveyors forming the series
• CPC Class Codes: B65G 59/12 characterised by de-stacking during transit

Abstract

An unstacking apparatus includes a feed conveyor for feeding stacks of items, and a decline unstacking section including at least first and second declined conveyors arranged in series. A stack of items being transferred from the feed conveyor to the first declined conveyor tilts forwardly to cause the items to slide forwardly off one another into a shingle arrangement on the first declined conveyor. The second declined conveyor includes an upstream end which is offset upwardly relative to a downstream end of the first declined conveyor, causing items to travel upwardly in order to pass from the first to the second declined conveyors. The second declined conveyor travels at a faster speed than the first declined conveyor for at least partially de-shingling the items. A transfer conveyor conveys items to an incline unstacking section which includes at least first and second incline conveyors arranged in series. A stack of items being transferred from the transfer conveyor to the first inclined conveyor tilts rearwardly to cause the items to slide rearwardly off one another into a shingle arrangement on the first inclined conveyor. The second inclined conveyor includes an upstream end which is offset downwardly relative to a downstream end of the first inclined conveyor, causing items to descend in order to pass from the first to the second inclined conveyors. The second inclined conveyor travels at a faster speed than the first inclined conveyor for at least partially de-shingling the items.

Claims

1. A decline unstacking apparatus comprising:

a feed conveyor for feeding stacks of items; and

a declined conveyor arrangement including at least first and second declined conveyors arranged in series, a first of the declined conveyors having an upstream end disposed at a discharge end of the feed conveyor, the first declined conveyor being declined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts forwardly and causes the items in the stack to slide forwardly off one another into a shingle arrangement on the first declined conveyor, wherein the leading end of an item is situated beneath the trailing end of a preceding item, the second declined conveyor including an upstream end disposed adjacent a downstream end of the first declined conveyor and traveling at a faster speed than the first declined conveyor for at least partially de-shingling the items received from the first declined conveyor.

2. The decline unstacking apparatus according to claim 1 further comprising a sensor for sensing items on the first declined conveyor;

and a controller for controlling a speed of the feed conveyor in response to signals from the sensor, for preventing the discharge of additional items onto the first declined conveyor until there is sufficient space on the first declined conveyor for receiving additional items.

3. The decline unstacking apparatus according to claim 1 wherein an upstream end of a conveying surface defined by the second declined conveyor is offset upwardly with respect to a path of travel of a conveying surface defined by a downstream end of the first declined conveyor, causing a downstream end of each item to be raised when passing from the first declined conveyor to the second declined conveyor.

4. The decline unstacking apparatus according to claim 3 wherein the downstream end of the first declined conveyor and the upstream end of the second declined conveyor travel around respective first and second support pulleys, the upstream end of the conveying surface defined by the second declined conveyor being offset from the path of travel of the downstream end of the conveying surface defined by the first declined conveyor by a distance equal substantially to a radius of the second support pulley.

5. The decline stacking apparatus according to claim 3 wherein the sensor comprises a first sensor, and further including a second sensor for sensing items on the first declined conveyor, the second sensor disposed downstream of the first sensor and connected to the controller for regulating a speed of the second declined conveyor in accordance with signals from the second sensor.

6. The decline unstacking apparatus according to claim 1 wherein the sensor comprises a first sensor, and further including a second sensor for sensing items on the first declined conveyor, the second sensor disposed downstream of the first sensor and connected to the controller for regulating a speed of the second declined conveyor in accordance with signals from the second sensor.

7. The decline unstacking apparatus according to claim 1 wherein the declined conveyor arrangement includes at least three declined conveyors arranged in series.

8. The decline stacking apparatus according to claim 1 wherein the first and second declined conveyors comprise endless belts.

9. A decline unstacking apparatus comprising:

a feed conveyor for feeding stacks of items;

a declined conveyor arrangement including at least first and second declined conveyors arranged in series, a first of the declined conveyors having an upstream end disposed at a discharge end of the feed conveyor, the first declined conveyor being declined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts forwardly, causing the items in the stack to slide forwardly off one another into a shingle arrangement on the first declined conveyor, wherein the leading end of an item is situated beneath the trailing end of a preceding item;

the second declined conveyor including an upstream end disposed adjacent a downstream end of the first declined conveyor and traveling at a faster speed than the first declined conveyor for at least partially de-shingling the items received from the first declined conveyor;

an upstream end of a conveying surface defined by the second declined conveyor being offset upwardly with respect to a path of travel of a downstream end of a conveying surface defined by the first declined conveyor, causing a downstream end of each item to be raised when passing from the first declined conveyor to the second declined conveyor;

a sensor for sensing items on the first declined conveyor; and

a controller for regulating a speed of the second declined conveyor in response to a signal from the sensor, while always maintaining a speed of the second downstream conveyor greater than a speed of the first declined conveyor.

10. A method of unstacking items fed in stacked relationship in a bulk stream, comprising the steps of:

A) feeding the stream along a feed conveyor to an upstream end of a declined conveyor arrangement comprising at least first and second declined conveyors arranged in series, whereby a stack of items tilts forwardly as it reaches an upstream end of the first declined conveyor, causing the items to slide forwardly off one another into a shingle arrangement on the first declined conveyor, wherein the leading end of an item is situated beneath the trailing end of a preceding item; and

B) driving the second declined conveyor at a faster speed than the first declined conveyor whereby the second declined conveyor at least partially de-shingles the items received from the first declined conveyor.

11. The method according to claim 10, further comprising the steps of sensing items on the first declined conveyor;

and regulating a speed of the feed conveyor in response to signals from the sensor, to prevent the discharge of additional items onto the first declined conveyor until there is sufficient space on the first declined conveyor for receiving additional items.

12. The method according to claim 10, further comprising the step of raising a leading end of each item relative to a trailing end of the item when passing the item from the first declined conveyor to the second declined conveyor.

13. The method according to claim 10 wherein step C comprises a first sensing step, the method further comprising a second sensing step of sensing items on the first declined conveyor at a location spaced downstream of the first sensing step, and regulating a speed of the second declined conveyor in accordance with signals from the second sensing step while always driving the second declined conveyor faster than the first declined conveyor.

15. The incline unstacking apparatus according to claim 14 further comprising a sensor for sensing items on the first inclined conveyor;

and a controller for controlling a speed of the feed conveyor in response to signals from the sensor, for preventing the discharge of additional items onto the first inclined conveyor until there is sufficient space on the first inclined conveyor for receiving additional items.

16. The incline unstacking apparatus according to claim 14 wherein an upstream end of a conveying surface defined by the second inclined conveyor is offset downwardly with respect to a path of travel of a conveying surface defined by a downstream end of the first inclined conveyor, causing a downstream end of each item to descend when passing from the first inclined conveyor to the second inclined conveyor.

17. The incline unstacking apparatus according to claim 16 wherein the downstream end of the first inclined conveyor and the upstream end of the second inclined conveyor travel around respective first and second support pulleys, the upstream end of the conveying surface defined by the second inclined conveyor being offset from the path of travel of the downstream end of the conveying surface defined by the first inclined conveyor by a distance equal substantially to a radius of the second support pulley.

18. The decline stacking apparatus according to claim 16 wherein the sensor comprises a first sensor, and further including a second sensor for sensing items on the first inclined conveyor, the second sensor disposed downstream of the first sensor and connected to the controller for regulating a speed of the second inclined conveyor in accordance with signals from the second sensor.

19. The incline unstacking apparatus according to claim 14 wherein the sensor comprises a first sensor, and further including a second sensor for sensing items on the first inclined conveyor, the second sensor disposed downstream of the first sensor and connected to the controller for regulating a speed of the second inclined conveyor in accordance with signals from the second sensor.

20. The incline unstacking apparatus according to claim 14 wherein the inclined conveyor arrangement includes at least three inclined conveyors arranged in series.

21. The incline stacking apparatus according to claim 14 wherein the first and second inclined conveyors comprise endless belts.

14. An incline unstacking apparatus comprising:

a feed conveyor for feeding stacks of items; and

an inclined conveyor arrangement including at least first and second inclined conveyors arranged in series, a first of the inclined conveyors having an upstream end disposed at a discharge end of the feed conveyor, the first inclined conveyor being inclined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts rearwardly and causes the items in the stack to slide rearwardly off one another into a shingle arrangement on the first inclined conveyor, wherein the leading end of an item rests upon the trailing end of a preceding item, the second inclined conveyor including an upstream end disposed adjacent a downstream end of the first inclined conveyor and traveling at a faster speed than the first inclined conveyor for at least partially de-shingling the items received from the first inclined conveyor.

22. An incline unstacking apparatus comprising:

a feed conveyor for feeding stacks of items;

an inclined conveyor arrangement including at least first and second inclined conveyors arranged in series, a first of the inclined conveyors having an upstream end disposed at a discharge end of the feed conveyor, the first inclined conveyor being inclined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts forwardly, causing the items in the stack to slide forwardly off one another into a shingle arrangement on the first inclined conveyor, wherein the leading end of an item rests upon the trailing end of a preceding item;

the second inclined conveyor including an upstream end disposed adjacent a downstream end of the first inclined conveyor and traveling at a faster speed than the first inclined conveyor for at least partially de-shingling the items received from the first inclined conveyor;

an upstream end of a conveying surface defined by the second inclined conveyor being offset upwardly with respect to a path of travel of a downstream end of a conveying surface defined by the first inclined conveyor, causing a downstream end of each item to descend when passing from the first inclined conveyor to the second inclined conveyor;

a sensor for sensing items on the first inclined conveyor; and

a controller for regulating a speed of the second inclined conveyor in response to a signal from the sensor, while always maintaining a speed of the second downstream conveyor greater than a speed of the first inclined conveyor.

24. The method according to claim 23, further comprising the steps of sensing items on the first inclined conveyor;

and regulating a speed of the feed conveyor in response to signals from the sensor, to prevent the discharge of additional items onto the first inclined conveyor until there is sufficient space on the first inclined conveyor for receiving additional items.

25. The method according to claim 23, further comprising the step of raising a leading end of each item relative to a trailing end of the item when passing the item from the first inclined conveyor to the second inclined conveyor.

26. The method according to claim 23 wherein step C comprises a first sensing step, the method further comprising a second sensing step of sensing items on the first inclined conveyor at a location spaced downstream of the first sensing step, and regulating a speed of the second inclined conveyor in accordance with signals from the second sensing step while always driving the second inclined conveyor faster than the first inclined conveyor.

23. A method of unstacking items fed in stacked relationship in a bulk stream, comprising the steps of:

A) feeding the stream along a feed conveyor to an upstream end of an inclined conveyor arrangement comprising at least first and second inclined conveyors arranged in series, whereby a stack of items tilts forwardly as it reaches an upstream end of the first inclined conveyor, causing the items to slide forwardly off one another into a shingle arrangement on the first inclined conveyor, wherein the leading end of an item rests upon the trailing end of a preceding item; and

B) driving the second inclined conveyor at a faster speed than the first inclined conveyor whereby the second inclined conveyor at least partially de-shingles the items received from the first inclined conveyor.

27. An unstacking apparatus comprising a decline unstacking section, an incline unstacking section, and a transfer conveyor for transferring items from the decline unstacking section to the incline unstacking section, the decline unstacking section comprising:

a feed conveyor for feeding stacks of items, and

a declined conveyor arrangement including at least first and second declined conveyors arranged in series, a first of the declined conveyors having an upstream end disposed at a discharge end of the feed conveyor, the first declined conveyor being declined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts forwardly, causing the items in the stack to slide forwardly off one another into a shingle arrangement on the first declined conveyor, wherein the leading end of an item is situated beneath the trailing end of a preceding item;

the incline unstacking section comprising;

an inclined conveyor arrangement including at least first and second inclined conveyors arranged in series, a first of the inclined conveyors having an upstream end arranged to receive items that have traveled through the decline unstacking section, the first inclined conveyor being inclined from its upstream end at an angle relative to a direction of travel of the feed conveyor whereby a stack being discharged from the discharge end tilts rearwardly and causes the items in the stack to slide rearwardly off one another into a shingle arrangement on the first inclined conveyor, wherein the leading end of an item rests upon the trailing end of a preceding item, the second inclined conveyor including an upstream end disposed adjacent a downstream end of the first inclined conveyor and traveling at a faster speed than the first inclined conveyor for at least partially de-shingling the items received from the first inclined conveyor.

28. A method of unstacking items fed in stacked relationship in a bulk stream, comprising the steps of:

A) feeding the stream along a feed conveyor to an upstream end of a declined conveyor arrangement comprising at least first and second declined conveyors arranged in series, whereby a stack of items tilts forwardly as it reaches an upstream end of the first declined conveyor, causing the items to slide forwardly off one another into a shingle arrangement on the first declined conveyor, wherein the leading end of an item is situated beneath the trailing end of a preceding item;

B) driving the second declined conveyor at a faster speed than the first declined conveyor whereby the second declined conveyor at least partially de-shingles the items received from the first declined conveyor;

C) feeding the stream exiting the declined conveyor arrangement to an upstream end of an inclined conveyor arrangement comprising at least first and second inclined conveyors arranged in series, whereby a stack of items tilts forwardly as it reaches an upstream end of the first inclined conveyor, causing the items to slide off one another into a shingle arrangement on the first inclined conveyor, wherein the leading end of an item rests upon the trailing end of a preceding item; and

D) driving the second inclined conveyor at a faster speed than the first inclined conveyor whereby the second inclined conveyor at least partially de-shingles the items received from the first inclined conveyor.