BALER AND METHOD OF BINDING A BALE

Abstract

A baler includes: a bale forming channel, a reciprocating plunger configured to compress bale material in the bale forming channel to form a bale, and a binding system for binding a bale in the bale forming channel with a pair of twines that pass around opposite sides of the bale. The binding system includes a knotter that includes a rotary bill hook, a twine holder, a twine cutter and a stripper element. The bill hook includes a catching element that is configured to adopt an open configuration to release a retained twine from the bill hook after a knot formed by the knotter is removed from the bill hook by the stripper element, so that the cut end of the twine is not pulled through the knot. The catching element is moved to the open configuration by an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position.

Description

Claims

1. A baler comprising a bale forming channel, a reciprocating plunger configured to compress bale material in the bale forming channel to form a bale, and a binding system for binding a bale in the bale forming channel with a pair of twines that pass around opposite sides of the bale, the binding system comprising a knotter that includes a rotary bill hook that has a rotational axis, a twine holder, a twine cutter and a stripper element, wherein the binding system is configured to tie a first knot and a second knot successively in the twines during one full operating cycle of the binding system, wherein the bill hook is rotatable between a first position in which the bill hook engages the twines and a second position in which a knot formed by the knotter is stripped from the bill hook by the stripper element, wherein the bill hook includes a catching element that is configurable in a closed configuration to retain a twine to the bill hook and in an open configuration to release the twine from the bill hook, wherein the catching element is configured to adopt the open configuration to release a retained twine from the bill hook after a knot formed by the knotter is removed from the bill hook by the stripper element, so that the cut end of the twine is not pulled through the knot, and wherein the catching element is biased by a resilient biasing element towards the closed configuration and is moved to the open configuration by an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position.

2. A baler according to claim 1, wherein the opening element comprises a rotary drive element that drives movement of the catching element between the closed configuration and the open configuration, wherein the rotary drive element is rotatable relative to the bill hook while the bill hook is in the second position.

3. A baler according to claim 2, wherein the rotary drive element comprises a cam surface that engages a cam follower of the catching element.

4. A baler according to claim 1, wherein the opening element comprises a linear drive element that drives movement of the catching element between the closed configuration and the open configuration while the bill hook is in the second position.

5. A baler according to claim 1, wherein the catching element is moved to the open configuration by reducing or removing a biasing force applied by the resilient biasing element, so that the catching element opens in response to tension in the twine.

6. A baler according to claim 1, wherein: the first and second knots are tied successively by a single bill hook, andthe first and second knots are both loop knots.

7. A baler comprising a bale forming channel, a reciprocating plunger configured to compress bale material in the bale forming channel to form a bale, and a binding system for binding a bale in the bale forming channel with a pair of twines that pass around opposite sides of the bale, the binding system comprising a knotter that includes a rotary bill hook that has a rotational axis, a twine holder and a twine cutter, wherein the binding system is configured to tie a first knot and a second knot successively in the twines during one full operating cycle of the binding system, wherein: the first and second knots are tied successively by a single bill hook, andat least the second knot is a loop knot.

8. A baler according to claim 1, wherein the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp twines in at least one of the clamping notches against the retainer, and wherein the clamping notches are arranged asymmetrically around the periphery of the rotary disk.

9. A baler according to claim 8, wherein the drive for rotating the rotary disk includes a worm drive comprising a worm screw and a worm gear, wherein the worm screw is shifted axially to adjust the rotary position of the rotary disk between tying of the first and second knots.

10. A baler according to claim 1, wherein the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp a twine in at least one of the clamping notches against the retainer, wherein the retainer is configured so that the twine can be guided across the retainer in two different positions depending on the rotational position of the rotary disk, comprising a first position in which the twine can be cut by the twine cutter and a second position in which the twine cannot be cut by the twine cutter.

11. A baler according to claim 7, wherein the bill hook is rotatable between a first position in which the bill hook engages the twines and a second position in which a knot formed by the knotter is stripped from the bill hook by the stripper element, wherein the bill hook includes a catching element that is configurable in a closed configuration to retain a twine to the bill hook and in an open configuration to release the twine from the bill hook, wherein the catching element is configured to adopt the open configuration to release a retained twine from the bill hook after a knot formed by the knotter is removed from the bill hook by the stripper element, so that the cut end of the twine is not pulled through the knot, and wherein the catching element is biased by a resilient biasing element towards the closed configuration and is moved to the open configuration by an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position.

12. A baler according to claim 11, wherein the opening element comprises a rotary drive element that drives movement of the catching element between the closed configuration and the open configuration, wherein the rotary drive element is rotatable relative to the bill hook while the bill hook is in the second position.

13. A baler according to claim 1, wherein the first knot and the second knot are both loop knots.

14. A baler according to claim 1, wherein the first and second knots are both right-hand knots.

15. A baler according to claim 1, wherein the twine cutter is configured to cut the twine to provide a cut end, and wherein the twine cutter is displaced from the bill hook to provide a length L of twine between the cut end and the rotational axis of the bill hook, wherein the length L fulfils one or more of the following definitions: L is at least 1.3 times, or at least 1.6 times, or at least 2.0 times the length of the bill hook from the rotational axis to the tip of the bill hook;L is at least 0.5 times, or at least 0.6 times, or at least 0.75 times the length of twine needed to wrap circumferentially around the bill hook: L is at least 9 times, or at least 11 times, or at least 14 times the diameter of the twine when tied around a bound bale;L is at least 34 mm, or at least 41 mm, or about 52 mm.

16. A baler according to claim 1, wherein the binding system further comprises a twine guide located between the twine holder and the bill hook.

17. A baler according to claim 16, wherein the twine cutter is located between the twine guide and the twine holder.

18. A method of binding a bale in a baler comprising a bale forming channel, a reciprocating plunger that compresses bale material in the bale forming channel to form a bale, and a binding system that binds a bale in the bale forming channel, the binding system comprising a knotter that includes a rotary bill hook having a rotational axis, a catching element, a twine holder, a twine cutter and a stripper element, the method comprising passing the twines around opposite sides of the bale, tying a first knot and a second knot successively in the twines during one full operating cycle of the binding system, rotating the bill hook between a first position in which the bill hook engages the twines and a second position in which a knot is stripped from the bill hook by the stripper element, resiliently biasing the catching element towards a closed configuration to retain a twine on the bill hook while a knot is formed, and moving the catching element to an open configuration by operation of an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position, to release the retained twine after the knot has been removed from the bill hook by the stripper element, so that a cut end of the twine is not pulled through the knot.

19. A method according to claim 18, further comprising driving movement of the catching element between the closed configuration and the open configuration by rotating an opening element relative to the bill hook while the bill hook is in the second position, said opening element comprising a rotary drive element.

20. A method according to claim 19, further comprising engaging a cam surface of the rotary drive element with a cam follower of the catching element.

21. A method according to claim 18, further comprising driving movement of the catching element between the closed configuration and the open configuration by operating an opening element comprising a linear drive element.

22. A method according to claim 18, further comprising moving the catching element to the open configuration by reducing or removing a biasing force applied by the resilient biasing element, so that the catching element opens in response to tension in the twine.

23. A method according to claim 18, further comprising: tying the first and second knots successively by a single bill hook, wherein the first and second knots are both loop knots.

24. A method of binding a bale in a baler comprising a bale forming channel, a reciprocating plunger that compresses bale material in the bale forming channel to form a bale, and a binding system that binds a bale in the bale forming channel with a pair of twines that pass around opposite sides of the bale, the binding system comprising a knotter that includes a rotary bill hook that has a rotational axis, a twine holder and a twine cutter, wherein the binding method comprises tying a first knot and a second knot successively in the twines during one full operating cycle of the binding system, wherein: the first and second knots are tied successively by a single bill hook, andat least the second knot is a loop knot.

25. A method according to claim 18, wherein the twine holder comprises a rotary disk with a plurality of clamping notches arranged asymmetrically around a periphery of the rotary disk, and a retainer adjacent the periphery of the rotary disk, the method comprising driving rotation the rotary disk to clamp twines in at least one of the clamping notches against the retainer.

26. A method according to claim 25, further comprising driving the rotary disk with a worm drive comprising a worm screw and a worm gear, and shifting the worm screw axially to adjust the rotary position of the rotary disk between tying of the first and second knots.

27. A method according to claim 18, wherein the twine holder comprises a rotary disk with a plurality of clamping notches, a retainer adjacent a periphery of the rotary disk, and a drive for rotating the rotary disk to clamp a twine in at least one of the clamping notches against the retainer, the method comprising guiding the twine across the retainer in two different positions by adjusting the rotational position of the rotary disk, said positions comprising a first position in which the twine can be cut by the twine cutter and a second position in which the twine cannot be cut by the twine cutter.

28. A method according to claim 27, further comprising rotating the bill hook between a first position in which the bill hook engages the twines and a second position in which a knot is stripped from the bill hook by the stripper element, resiliently biasing the catching element towards a closed configuration to retain a twine on the bill hook while a knot is formed, and moving the catching element to an open configuration by operation of an opening element that acts against the resilient biasing element, without rotating the bill hook beyond the second position, to release the retained twine after the knot has been removed from the bill hook, so that the cut end of the twine is not pulled through the knot.

29. A method according to claim 28, further comprising driving movement of the catching element between the closed configuration and the open configuration by rotating an opening element relative to the bill hook while the bill hook is in the second position, said opening element comprising a rotary drive element.

30. A method according to claim 18, wherein the first knot and the second knot are both tied as loop knots.

31. A method according to claim 18, wherein the first and second knots are both tied as right-hand knots.

32. A method according to claim 18, further comprising cutting the twine to provide a length L of twine between a cut end of the twine and the rotational axis of the bill hook, wherein the length L fulfils one or more of the following definitions: L is at least 1.3 times, or at least 1.6 times, or at least 2.0 times the length of the bill hook from the rotational axis to the tip of the bill hook;L is at least 0.5 times, or at least 0.6 times, or at least 0.75 times the length of twine needed to wrap circumferentially around the bill hook: L is at least 9 times, or at least 11 times, or at least 14 times the diameter of the twine when tied around a bound bale;L is at least 34 mm, or at least 41 mm, or about 52 mm.

33. A method according to claim 18, further comprising guiding the twine by means of a twine guide located between the twine holder and the bill hook.

34. A method according to claim 33, further comprising cutting the twine between the twine guide and the twine holder.