EP-4739587-A1 - STRAPPING DEVICE WITH STRAP-CLEANING OPTION

Abstract

Various embodiments of the present disclosure provide a strapping device including a tensioning plate, a rotatable tensioning wheel adjacent the tensioning plate, a first weld plate, a second weld plate, a motor operably connected to one of the first and second weld plates, and a controller. The controller is configured to, responsive to initiation of a sealing cycle with a strap-cleaning option active, control the motor to: oscillate the one of the first and second weld plates relative to the other at a first frequency for a first period; after the first period, oscillate the one of the first and second weld plates relative to the other at a second frequency for a second period, wherein the second frequency is greater than the first frequency; and after the second period, stop oscillating the one of the first and second weld plates relative to the other.

Inventors

• Höhn, Jürgen

Assignees

• Signode Industrial Group LLC

Dates

Publication Date

20260513

Application Date

20240813

Claims (20)

1. 1. A strapping device comprising: a tensioning plate; a rotatable tensioning wheel adjacent the tensioning plate; a first weld plate; a second weld plate, wherein the first weld plate is movable toward and away from the second weld plate; a motor operably connected to one of the first and second weld plates; and a controller configured to control the motor to: (a) oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at a first frequency for a first period; (b) after the first period, oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at a second frequency for a second period, wherein the second frequency is greater than the first frequency; and (c) after the second period, stop oscillating the one of the first and second weld plates relative to the other of the first and second weld plates.
2. 2. The strapping device of claim 1, the controller is configured to carry out (a)-(c) responsive to initiation of a sealing cycle with a strap-cleaning option active.
3. 3. The strapping device of claim 2, wherein the controller is further configured to, responsive to initiation of the sealing cycle with the strap-cleaning option inactive: oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at a third frequency for a third period; and after the third period, stop oscillating the one of the first and second weld plates relative to the other of the first and second weld plates.
4. 4. The strapping device of claim 3, wherein the second frequency and the third frequency are substantially the same.
5. 5. The strapping device of claim 4, wherein the second period and the third period are substantially the same.
6. 6. The strapping device of claim 4, wherein the second and third periods are longer than the first period.
7. 7. The strapping device of claim 1, wherein: the first period comprises one of: a first preset time period and a first preset quantity of revolutions of an output shaft of the motor; and the second period comprises one of: a second preset time period and a second preset quantity of revolutions of the output shaft of the motor.
8. 8. The strapping device of claim 1, wherein the controller is configured to control the motor to oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at: the first frequency by controlling the motor to rotate an output shaft of the motor at a first rotational speed; and the second frequency by controlling the motor to rotate the output shaft of the motor at a second rotational speed, wherein the second rotational speed is greater than the first rotational speed.
9. 9. The strapping device of claim 1, further comprising: a support comprising the second weld plate; and a weld arm supporting the first weld plate such that the first weld plate is oscillatable relative to the weld arm and the second weld plate, wherein the weld arm is pivotable relative to the second weld plate to move the first weld plate toward and away from the second weld plate.
10. 10. The strapping device of claim 9, further comprising an eccentric shaft operably connected to the first weld plate such that rotation of the eccentric shaft causes the first weld plate to oscillate relative to the second weld plate, wherein the motor is operably connected to the eccentric shaft to rotate the eccentric shaft, wherein the controller is configured to control the motor to oscillate the first weld plate relative to the second weld plate at: the first frequency by controlling the motor to rotate an output shaft of the motor at a first rotational speed; and the second frequency by controlling the motor to rotate the output shaft of the motor at a second rotational speed, wherein the second rotational speed is greater than the first rotational speed.
11. 11. A method of operating a strapping device, the method comprising: tensioning a strap around a load such that an upper layer of the strap and a lower layer of the strap are positioned between a first weld plate and a second weld plate; moving the first weld plate to sandwich the upper and lower layers of the strap between the first and second weld plates; oscillating one of the first and second weld plates relative to the other of the first and second weld plates at a first frequency for a first period; after the first period, oscillating the one of the first and second weld plates relative to the other of the first and second weld plates at a second frequency for a second period to locally melt and join portions of the upper and lower layers of the strap, wherein the second frequency is greater than the first frequency; and after the second period, stopping the oscillation of the one of the first and second weld plates relative to the other of the first and second weld plates.
12. 12. The method of claim 11, wherein the second period is longer than the first period.
13. 13. The method of claim 11, wherein oscillating the one of the first and second weld plates relative to the other of the first and second weld plates comprises controlling a motor operably connected to the one of the first and second weld plates.
14. 14. The method of claim 13, wherein: the first period comprises one of: a first preset time period and a first preset quantity of revolutions of an output shaft of the motor; and the second period comprises one of: a second preset time period and a second preset quantity of revolutions of the output shaft of the motor.
15. 15. The method of claim 11 , further comprising oscillating the one of the first and second weld plates relative to the other of the first and second weld plates at: the first frequency by controlling the motor to rotate an output shaft of a motor at a first rotational speed; and the second frequency by controlling the motor to rotate the output shaft of the motor at a second rotational speed, wherein the second rotational speed is greater than the first rotational speed.
16. 16. The method of claim 11, wherein moving the first weld plate to sandwich the upper and lower layers of strap between the first and second weld plates comprises pivoting a weld arm supporting the first weld plate toward a support comprising the second weld plate.
17. 17. The method of claim 16, further comprising rotating an eccentric shaft operably connected to the first weld plate to cause the first weld plate to oscillate relative to the second weld plate.
18. 18. The method of claim 17, further comprising controlling a motor to rotate the eccentric shaft.
19. 19. The method of claim 18, further comprising controlling the motor to pivot the weld arm.
20. 20. The method of claim 19, further comprising oscillating the first weld plate relative to the second weld plates at: the first frequency by controlling the motor to rotate an output shaft of a motor at a first rotational speed; and the second frequency by controlling the motor to rotate the output shaft of the motor at a second rotational speed, wherein the second rotational speed is greater than the first rotational speed.

Description

STRAPPING DEVICE WITH STRAP-CLEANING OPTION Priority [0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/520,770, filed August 21, 2023, the entire contents of which is incorporated herein by reference. Field [0002] The present disclosure relates to strapping devices, and more particularly to strapping devices configured to tension strap around a load and to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load. Background [0003] Strapping devices are configured to tension strap around a load and to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load. Some strapping devices utilize friction welding to attach overlapping upper and lower strap layers to one another. To use one of these strapping devices to form a tensioned strap loop around a load, an operator pulls strap leading end first from a strap supply, wraps the strap around the load, and a lower layer of the strap including the leading end of the strap below an upper layer of the strap. The operator introduces the overlapped strap layers into the strapping device and presses a button to initiate a tensioning cycle during which a tensioning wheel rotates to move the upper stray layer over the lower strap layer and tension the strap around the load. After completion of the tensioning cycle, a sealing cycle is initiated. During the sealing cycle, a weld shoe sandwiches the strap layers against a toothed weld plate. A motor oscillates the toothed weld shoe at a high frequency. The oscillating weld shoe oscillates the upper strap layer relative to the lower strap layer, which generates friction between portions of the overlapping strap layers. This friction locally melts and joins those portions of the overlapping strap layers, thereby attaching the upper and lower strap layers to form the tensioned strap loop. [0004] Strapping devices are sometimes used in wet or dirty environments, such as outdoors at a lumber mill. In situations like these, the strap may be wet or dirty when introduced into the strapping device. The moisture or debris on the strap can interfere with the frictionwelding process, resulting in weaker strap joints. Summary [0005] Various embodiments of the present disclosure provide a strapping device including a tensioning plate, a rotatable tensioning wheel adjacent the tensioning plate, a first weld plate, a second weld plate, a motor operably connected to one of the first and second weld plates, and a controller. The first weld plate is movable toward and away from the second weld plate. The controller is configured to, responsive to initiation of a sealing cycle with a strapcleaning option active, control the motor to: oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at a first frequency for a first period; after the first period, oscillate the one of the first and second weld plates relative to the other of the first and second weld plates at a second frequency for a second period, wherein the second frequency is greater than the first frequency; and after the second period, stop oscillating the one of the first and second weld plates relative to the other of the first and second weld plates. Brief Description of the Figures [0006] Figures 1A and IB are perspective views of one example embodiment of a strapping device of the present disclosure. [0007] Figure 1C is a block diagram of certain components of the strapping device of Figures 1A and IB. [0008] Figures 2A-2C are diagrammatic views of the strapping device of Figures 1A and IB securing a load to a pallet. [0009] Figure 2D is a perspective view of a friction- weld strap joint formed by the strapping device of Figure 1 A to attach two overlapping strap layers. [0010] Figures 3 A and 3B are perspective views of the working assembly of the strapping device of Figures 1A and IB. [0011] Figure 4A is a perspective view of part of the working assembly of Figures 3A and 3B. [0012] Figure 4B is a cross-sectional perspective view of part of the working assembly of Figures 3A and 3B. [0013] Figures 5A-5F are side views of part of one side of the working assembly of Figures 3A and 3B showing the tensioning assembly moving from its tensioning position to its strap-insertion position and back to its tensioning position. Certain components of the working assembly are not shown for clarity. [0014] Figure 6A is a front elevational view of the working assembly of Figures 3A and 3B showing the sealing assembly in a home configuration. [0015] Figure 6B is a front elevational view similar to Figure 6A showing the sealing assembly between the home configuration and a sealing configuration and forcing the overlapping upper and lower strap layers against the weld plate. [0016] Figure 6C is a front elevational view similar to Figures 6A and 6B showing the sealing assembly in the sealing c