Stretch wrapping machine supporting multiple discrete pre-stretch amounts

Patent metadata

Field	Value
Publication number	US-11518561-B2
Application number	US-202016929669-A
Country	US
Kind code	B2
Filing date	Jul 15, 2020
Priority date	Aug 9, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A packaging material dispenser of a stretch wrapping machine supports multiple discrete amounts of pre-stretch in a reliable and cost-effective manner in part by incorporating a loop drive assembly with multiple pre-stretch rate wheels capable of being used to drive a driven wheel associated with a pre-stretch roller at different discrete rates of rotation relative to another pre-stretch roller.

First claim

What is claimed is:

1. An apparatus for wrapping a load with packaging material, the apparatus comprising:
a packaging material dispenser for dispensing packaging material to the load, the packaging material dispenser including:
a first pre-stretch roller and a second pre-stretch roller; and
a pre-stretch drive operably coupling the first and second pre-stretch rollers to one another to drive the second pre-stretch roller at one of a first rate of rotation and a second rate of rotation relative to the first pre-stretch roller, the pre-stretch drive including:
a drive gear operably coupled to rotate the first pre-stretch roller;
a driven wheel operably coupled to rotate the second pre-stretch roller;
a first pre-stretch rate assembly and a second pre-stretch rate assembly, each of the first and second pre-stretch rate assemblies including a wheel operably coupled to rotate with an associated gear, the wheel and the associated gear of the first pre-stretch rate assembly configured to cause the second pre-stretch roller to rotate at the first rate of rotation relative to the first pre-stretch roller, and the wheel and the associated gear of the second pre-stretch rate assembly configured to cause the second pre-stretch roller to rotate at the second rate of rotation relative to the first pre-stretch roller;
a continuous loop member operably coupling the wheel of the first pre-stretch rate assembly and the wheel of the second pre-stretch rate assembly to the driven wheel;
a rate selection gear operably engaged with the drive gear and being movable between a first position and a second position, wherein in the first position the rate selection gear operably engages with the gear of the first pre-stretch rate assembly to operably couple the drive gear to the gear of the first pre-stretch rate assembly, and wherein in the second position the rate selection gear operably engages with the gear of the second pre-stretch rate assembly to operably couple the drive gear to the gear of the second pre-stretch rate assembly; and

a rotational drive configured to generate relative rotation between the packaging material dispenser and the load about a center of rotation.

2. The apparatus of claim 1 , wherein each of the driven wheel, the wheel of the first pre-stretch rate assembly, and the wheel of the second pre-stretch rate assembly is a pulley and the continuous loop member is a belt.

3. The apparatus of claim 1 , wherein each of the driven wheel, the wheel of the first pre-stretch rate assembly, and the wheel of the second pre-stretch rate assembly is a toothed pulley and the continuous loop member is a toothed belt.

4. The apparatus of claim 1 , wherein each of the driven wheel, the wheel of the first pre-stretch rate assembly, and the wheel of the second pre-stretch rate assembly is a sprocket and the continuous loop member is a chain.

5. The apparatus of claim 1 , wherein the pre-stretch drive further includes a rate selection wheel that is rotatably mounted about a common axis of rotation with the rate selection gear, wherein the continuous loop member operably couples the rate selection wheel to the driven wheel, the wheel of the first pre-stretch rate assembly, and the wheel of the second pre-stretch rate assembly.

6. The apparatus of claim 1 , wherein the pre-stretch drive further includes a tensioner wheel operably coupled to the driven wheel, the wheel of the first pre-stretch rate assembly, and the wheel of the second pre-stretch rate assembly to maintain substantially constant tension in the continuous loop member.

7. The apparatus of claim 1 , wherein the wheel and the associated gear of the first pre-stretch rate assembly are coaxial, the wheel and the associated gear of the second pre-stretch rate assembly are coaxial, the driven wheel and the second pre-stretch roller are coaxial, and the drive gear and the first pre-stretch roller are coaxial.

8. The apparatus of claim 1 , wherein each of the first and second pre-stretch rollers, the driven wheel, the drive gear, the wheel and the associated gear of the first pre-stretch rate assembly, the wheel and the associated gear of the second pre-stretch rate assembly, and the rate selection gear rotate about respective rotational axes that are generally parallel to one another.

9. The apparatus of claim 1 , wherein the rate selection gear is movable between the first and second positions through generally linear movement.

10. The apparatus of claim 1 , wherein the rate selection gear is movable between the first and second positions through generally rotational movement.

11. The apparatus of claim 1 , wherein the pre-stretch drive further includes a rotatable actuation arm having an axis of rotation, wherein the rate selection gear is rotatably mounted to the rotatable actuation arm, and wherein the first position of the rate selection gear corresponds to a first rotational position of the actuation arm and the second position of the rate selection gear corresponds to a second rotational position of the actuation arm.

12. The apparatus of claim 11 , wherein the axis of rotation of the actuation arm is coaxial with the drive gear.

13. The apparatus of claim 11 , wherein the pre-stretch drive further includes a position selector operably coupled to the actuation arm to rotate the actuation arm between the first and second rotational positions.

14. The apparatus of claim 13 , wherein the position selector is operably coupled to the actuation arm through a pin and slot mechanism.

15. The apparatus of claim 14 , wherein the pin and slot mechanism includes a pin disposed on the actuation arm and a slot disposed on the position selector.

16. The apparatus of claim 15 , wherein the position selector is rotatable about an axis of rotation, wherein when the actuation arm is in the first rotational position, the pin is oriented proximate a first end of the slot and when the actuation arm is in the second rotational position, the pin is oriented proximate a second end of the slot.

17. The apparatus of claim 16 , wherein the pre-stretch drive further includes a bias assembly configured to bias the actuation arm towards at least one of the first and second rotational positions.

18. The apparatus of claim 17 , wherein the bias assembly biases the actuation arm towards the first rotational position when the actuation arm is within a first range of rotational positions adjacent the first rotational position and biases the actuation arm towards the second rotational position when the actuation arm is within a second range of rotational positions adjacent the first rotational position.

19. The apparatus of claim 18 , wherein the bias assembly includes a rotatable spring support disposed adjacent the position selector and a spring anchored between a first spring mount and a second spring mount respectively disposed on the rotatable spring support and the position selector, and wherein the rotatable spring support and the position selector include intermeshed teeth such that rotation of the actuation arm away from either of the first and second rotational positions rotates the rotatable spring support and the position selector to increase a distance between the first and second spring mounts.

20. The apparatus of claim 11 , further comprising a controlled actuator configured to rotate the actuation arm between the first and second rotational positions.

21. The apparatus of claim 20 , wherein the controlled actuator is a linear actuator, a pneumatic actuator, a hydraulic actuator

Assignees

• Lantech Com Llc

Inventors

• Martin Curtis W

Classifications

• B65B11/025

  by webs revolving around stationary articles · CPC title

• B65B2011/002

  Prestretching mechanism in wrapping machines · CPC title

• B65B41/16 Primary

  by rollers · CPC title