Spiral conveyor apparatus with automatic flow control

• US 20010004043A1
• Filed: 02/05/2001
• Published: 06/21/2001
• Est. Priority Date: 08/19/1997
• Status: Active Grant

• Current Assignee: Donald F. Belz, Duane L. Glass
• Original Assignee: Donald F. Belz, Duane L. Glass
• Inventors: Belz, Donald F., Glass, Duane L.
• Granted Patent: US 6,398,014 B2
• Time in Patent Office: Days
• US Class Current: 198/572
• CPC Class Codes: B65G 1/08 the articles being fed by gravity braking arrangements for roller-ways B65G13/075; separating or stopping elements B65G47/88
• CPC Class Codes: B65G 13/08 of curved form; with branch-offs
• CPC Class Codes: B65G 13/11 Roller frames
• CPC Class Codes: B65G 2207/24 Helical or spiral conveying path
• CPC Class Codes: B65G 43/08 Control devices operated by article or material being fed, conveyed or discharged and controlling the discharging devices B65G47/42
• CPC Class Codes: B65G 47/261 Accumulating articles

Abstract

A spiral conveyor with automatic flow control includes a plurality of curved segments connected to form a spiral for the flow by gravity of articles from an upper level to a lower level. Each of the segments includes freely rotating skate wheels forming a conveying surface and a controlled, powered cylindrical roller. A sensor mounted in each segment senses the presence of an article in the segment. A controller receives the signals from the sensors and activates the associated roller for transport mode to assist articles through the conveyor if the path is clear, or if the downstream portion of the conveyor is blocked, to reverse the roller for accumulate mode to hold articles in the segment until the path is cleared.

Claims

1. A spiral conveyor apparatus, comprising:

a plurality of conveyor segments arranged as a spiral, including at least an entry segment at a first level and an exit segment at a second level, each conveyor segment having a plurality of freely rotatable roller devices forming a conveying surface;

a powered roller mounted in each segment, each powered roller being individually powered and individually controllable for selected rotation;

means for sensing a conveyed article in each conveyor segment; and

means for receiving signals from the sensing means and responsively controlling the powered rollers in a transport mode for transport of articles and in an accumulate mode for accumulation of articles.

2. The apparatus as claimed in

claim 1

, wherein said means for controlling the powered rollers is configured to activate a roller in a segment in the transport mode upon receiving a signal that an article is sensed in the segment and receiving a signal that a segment immediately downstream of the subject segment is clear to transport articles.

3. The apparatus as claimed in

claim 1

, wherein said means for controlling the powered rollers is configured to control a roller in a segment in the accumulation mode upon receiving a signal that an article is sensed in the segment and receiving a signal that an additional article has been present in a segment immediately downstream of the subject segment for a predetermnined time duration.

4. The apparatus as claimed in

claim 3

, wherein the predetermined time duration is at least two seconds.

5. The apparatus as claimed in

claim 1

, wherein said means for sensing the conveyed articles includes a plurality of sensing devices, one device positioned at each conveyor segment upstream of the powered roller.

6. The apparatus as claimed in

claim 5

, wherein the sensing devices are photocell devices.

7. The apparatus as claimed in

claim 1

, wherein each conveyor segment defines an arc of at least 45°

.

8. The apparatus as claimed in

claim 1

, wherein each conveyor segment defines an arc of at least 90°

.

9. The apparatus as claimed in

claim 1

, further comprising a takeaway conveyor connected to receive conveyed articles from the exit segment and means for sensing conveyed articles in the takeaway conveyor.

10. The apparatus as claimed in

claim 1

, wherein said means for controlling the powered rollers is configured to activate the accumulate mode upon receiving a signal indicating an article in an exit segment for at least a predetermined length of time, wherein said means for controlling the powered rollers includes means for activating the powered rollers to rotate in reverse to maintain the article in the exit segment.

11. A spiral conveyor apparatus, comprising:

a plurality of conveyor segments arranged as a spiral, including at least an entry segment at a first level and an exit segment at a second level, each conveyor segment having a plurality of freely rotatable roller devices forming a conveying surface;

a powered roller mounted in each segment, the powered roller being individually powered and individually controllable for selected rotation;

means for sensing a conveyed article in the conveyor segment; and

means for receiving signals from the sensing means and responsively controlling the powered rollers in a transport mode for transport of articles and in an accumulate mode for accumulation of articles.

12. The apparatus as claimed in

claim 11

, wherein said means for controlling the powered rollers is configured to activate a roller in a segment in the transport mode upon receiving a signal that an article is sensed in the segment and receiving a signal that a segment immediately downstream of the subject segment is clear to transport articles.

13. The apparatus as claimed in

claim 11

, wherein said means for controlling the powered rollers is configured to controller a roller in a segment in the accumulation mode upon receiving a signal that an article is sensed in the segment and receiving a signal that an additional article has been present in a segment immediately downstream of the subject segment for a predetermined time duration.

14. The apparatus as claimed in

claim 13

, wherein the predetermined time duration is at least two seconds.

15. The apparatus as claimed in

claim 11

, wherein said means for sensing the conveyed articles includes a plurality of sensing devices, one device positioned at each conveyor segment upstream of the powered roller.

16. The apparatus as claimed in

claim 15

, wherein the sensing devices are photocell devices.

17. The apparatus as claimed in

claim 11

, wherein each conveyor segment defines an are of at least 45°

.

18. The apparatus as claimed in

claim 17

, wherein each conveyor segment defines an arc of at least 90°

.

19. The apparatus as claimed in

claim 11

, further comprising a takeaway conveyor connected to receive conveyed articles from the exit segment and means for sensing conveyed articles in the takeaway conveyor.

20. The apparatus as claimed in

claim 11

, wherein said means for controlling the powered rollers is configured to activate the accumulate mode upon receiving a signal indicating an article in an exit segment for at least a predetermined length of time, wherein said means for controlling the powered rollers includes means for activating the powered rollers to rotate in reverse to maintain the article in the exit segment.

21. A power assisted, gravity conveyor apparatus, comprising:

a frame forming a conveyor path from a first level to a second level,

a plurality of freely rotatable roller devices mounted in the frame to provide a gravity powered conveying path,

a plurality of individually powered rollers individually controllable to operate alternatively in a transport mode and in an accumulate mode, the powered rollers mounted on the frame at predetermined distance intervals along the conveying path;

means for sensing a conveyed article adjacent each powered roller; and

control means for individually controlling a subject powered roller responsive to a signal from the sensing means of a conveyed article approaching said subject powered roller, wherein when a signal indicates that a powered roller immediately downstream is clear for transport, the control means controls the subject powered roller for transport, and when a signal indicates that a powered roller immediately downstream of the subject powered roller is blocked, the control means controls the subject powered roller for accumulation.

22. The conveyor apparatus as claimed in

claim 21

, wherein the sensing means includes a plurality of sensors mounted on the frame, wherein one sensor is mounted adjacent to each of the powered rollers, and wherein said control means is connected to receive signals from each of the sensors.