Stretch wrapping machine with dispense rate control based on sensed rate of dispensed packaging material and predicted load geometry

Patent metadata

Field	Value
Publication number	US-11479378-B2
Application number	US-202017014489-A
Country	US
Kind code	B2
Filing date	Sep 8, 2020
Priority date	Sep 9, 2019
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A method, apparatus and program product control a dispense rate of a packaging material dispenser of a stretch wrapping apparatus by utilizing a combination of a sensed rate of packaging material exiting the dispenser and a predicted geometric relationship between the packaging material dispenser and the load.

First claim

What is claimed is:

1. A method of wrapping a load with packaging material using a wrapping apparatus of a type including a packaging material dispenser for dispensing packaging material to the load, the method comprising:
generating relative rotation between the packaging material dispenser and the load about a center of rotation;
sensing a rate of the packaging material exiting the packaging material dispenser; and
controlling a dispense rate of the packaging material dispenser during the relative rotation based at least in part on a geometric relationship between the packaging material dispenser and a calculated location of at least one corner of the load within a plane perpendicular to the center of rotation, and further based at least in part on the sensed rate of the packaging material exiting the packaging material dispenser, wherein the calculated location of the at least one corner is calculated independent of the sensed rate of packaging material exiting the packaging material dispenser.

2. The method of claim 1 , wherein the at least one corner includes a first corner, the method further comprising calculating the position of the first corner based at least in part upon one or more dimensions of the load.

3. The method of claim 2 , wherein the one or more dimensions includes a length and a width.

4. The method of claim 2 , wherein the one or more dimensions are input by an operator.

5. The method of claim 2 , wherein the one or more dimensions are sensed by one or more sensors directed at the load.

6. The method of claim 2 , wherein the one or more dimensions are retrieved from a wrap profile stored in the wrapping apparatus.

7. The method of claim 2 , wherein the one or more dimensions are based at least in part upon a standard load type representative of the load, and wherein the one or more dimensions are determined without sensing the one or more dimensions from the load and without receiving input from an operator or a wrap profile specific to the load.

8. The method of claim 2 , wherein calculating the position of the first corner is further based at least in part upon an offset of the load from the center of rotation.

9. The method of claim 8 , wherein the offset is based at least in part upon a standard load type representative of the load, and wherein the offset is determined without sensing the offset from the load and without receiving input from an operator or a wrap profile specific to the load.

10. The method of claim 1 , wherein the packaging material dispenser includes a pre-stretch assembly, and wherein sensing the rate of the packaging material exiting the packaging material dispenser includes sensing rotation of an idle roller disposed downstream of the pre-stretch assembly.

11. The method of claim 10 , wherein the idle roller forms an exit point for the packaging material dispenser.

12. A method of wrapping a load with packaging material using a wrapping apparatus of a type including a packaging material dispenser for dispensing packaging material to the load, the method comprising:
generating relative rotation between the packaging material dispenser and the load about a center of rotation;
sensing a rate of the packaging material exiting the packaging material dispenser; and
controlling a dispense rate of the packaging material dispenser during the relative rotation based at least in part on a geometric relationship between the packaging material dispenser and a calculated location of at least one corner of the load within a plane perpendicular to the center of rotation, and further based at least in part on the sensed rate of the packaging material exiting the packaging material dispenser, wherein the at least one corner of the load includes a first corner, and wherein controlling the dispense rate of the packaging material dispenser includes determining a demand at a first rotational position about the center of rotation using a curve fit between second and third rotational positions that are respectively before and after the first rotational position about the center of rotation and for which predicted demands are determined.

13. The method of claim 12 , wherein controlling the dispense rate of the packaging material dispenser further includes determining the predicted demands for the second and third rotational positions based at least in part upon the calculated position for the first corner.

14. The method of claim 13 , wherein the curve is a demand curve defining a demand at each of a plurality of rotational positions between the second and third rotational positions, and wherein controlling the dispense rate further includes determining the first dispense rate by scaling a demand from the demand curve based at least in part upon a wrap force parameter.

15. The method of claim 12 , wherein the curve defines, for each of a plurality of rotational positions, a percentage of a girth of a standard load type representative of the load.

16. The method of claim 12 , wherein the curve defines, for each of a plurality of rotational positions, a percentage of a girth of the load, wherein the girth of the load is based upon input of one or more dimensions of the load.

17. The method of claim 12 , wherein the curve includes a portion of a sinusoidal curve fit between the second and third rotational positions.

18. The method of claim 12 , further comprising determining the first dispense rate at the first rotational position further by applying a rotational data shift to offset system lag.

19. The method of claim 18 , wherein the rotational data shift is variable based at least in part upon a rate of relative rotation between the packaging material dispenser and the load.

20. The method of claim 12 , wherein the curve includes a plurality of segments spanning a full revolution about the center of rotation, each segment fit between two or more rotational positions for which predicted demands are determined.

21. The method of claim 20 , wherein each segment includes a sine curve fit between two or more rotational positions for which predicted demands are determined.

22. The method of claim 20 , wherein the plurality of segments includes eight segments, each of the eight segments spanning between a rotational position associated with a local minimum in demand and a rotational position associated with a local maximum in demand.

23. A method of wrapping a load with packaging material using a wrapping apparatus of a type including a packaging material dispenser for dispensing packaging material to the load, the method comprising:
generating relative rotation between the packaging material dispenser and the load about a center of rotation;
sensing a rate of the packaging material exiting the packaging material dispenser; and
controlling a dispense rate of the packaging material dispenser during the relative rotation based at least in part on a geometric relationship between the packaging material dispenser and a calculated location of at least one corner of the load within a plane perpendicular to the center of rotation, and further based at least in part on the sensed rate of the packaging material exiting the packaging material dispenser, wherein controlling the dispense rate of the packaging material dispenser based at least in part on the sensed rate of the packaging material exiting the packaging material dispenser includes generating a signal from the sensed rate that varies based upon an actual girth of the load at an elevation at which t

Assignees

• Lantech Com Llc

Inventors

• Mitchell Michael P

Classifications

• B65B11/045 Primary

  by rotating platforms supporting the articles · CPC title

• B65B2011/002

  Prestretching mechanism in wrapping machines · CPC title

• B65B2210/18

  the web dispenser being mounted on a rotary ring · CPC title

• B65B57/06 Primary

  and operating to control, or to stop, the feed of articles or material to be packaged · CPC title

• B65B57/04

  and operating to control, or to stop, the feed of such material, containers, or packages · CPC title