Baler and method of baling

Abstract

A baler apparatus includes a baling chamber including at least one adjustable wall for adjusting compression of a body of bale material. A reciprocating plunger is operable to compress the bale material and a binding device binds the compressed material to form a bale by use of twine loops. An adjustment mechanism increases as a length of outer twine loops when binding the bale relative to the inner twine loops, to reduce compression within part of the body of bale material and avoid twine breakage that can otherwise occur as a bale is ejected from the baler.

Claims

1. A baler apparatus comprising: a baling chamber including a channel including an inlet end and an outlet end and at least one adjustable wall adjusting compression of a body of bale material by controlling pressure applied to the body of bale material during formation of a bale; a reciprocating plunger adjacent the inlet end of the baling chamber operable to compress a body of bale material within the baling chamber; a binding device configured for binding the compressed body of bale material to form a bale by use of twine loops; and an extension device configured for extending a length of outermost twine loops at binding of the bale to be greater than a length of innermost twine loops, to reduce compression within an outer part of the body of bale material.

2. The baler apparatus of claim 1, wherein the extension device extends the length of the outermost twine loops in response to factors including type of bale material and environmental conditions.

3. The baler apparatus of claim 1, wherein the extension device includes a roller or guide.

4. The baler apparatus of claim 3, wherein the roller or guide is locatable for engagement against an outside of one of the twine loops.

5. The baler apparatus of claim 3, further comprising a twine guide guiding the twine over the roller or guide.

6. The baler apparatus of claim 3, wherein the roller or guide is located adjacent a knotting device.

7. The baler apparatus of claim 1, wherein the binding device is configured to close each of the twine loops with one single knot.

8. The baler apparatus of claim 1, wherein the binding device is configured to close each of the twine loops with two knots.

9. The baler apparatus of claim 1, wherein the extension device is configured to independently vary a length of individual twine loops per twine loop.

10. The baler apparatus of claim 1, wherein an extra loop length increase of the outermost twine loops is 1-3 cm relative to the innermost twine loops.

11. The baler apparatus of claim 1, wherein the extension device also increases second outermost twine loops by 1-2 cm relative to the innermost twine loops.

12. The baler apparatus of claim 1, wherein the extension device is configured to increase loop length of a twine by up to 25 cm from its regular length.

13. The baler apparatus of claim 1, wherein the extension device is removable or displaceable.

14. The baler apparatus of claim 1, wherein the extension device is fixedly but adjustably connected to the baler.

15. The baler apparatus of claim 1, wherein the increase of the length of the outermost twine loops is achieved by positioning a knotting device relatively further or at an adjustable distance from the bale when the outermost twine loops are formed.

16. A method of baling bale material in a baler apparatus including a baling chamber including a channel having an inlet end and an outlet end and at least one adjustable wall adjusting compression of a body of bale material by controlling pressure applied to the body of bale material during formation of a bale, a reciprocating plunger adjacent the inlet end of the baling chamber, and a binding device, the method comprising: activating the reciprocating plunger to compress the body of bale material in the baling chamber; and binding the compressed body of the bale material with twine loops to form a bale, wherein the binding includes using an extension device to extend a length of outermost twine loops to be greater than a length of innermost twine loops around the compressed bale material, at least during closing of a loop, to form the bale and reduce compression within an outer part of the bale.

17. The baler apparatus of claim 1, wherein the extension device includes a plurality of rollers and each roller of the plurality of rollers is configured to adjust a length of a respective twine loop independently from lengths of the other twine loops.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an isometric view showing the main components of a baling machine;

(2) FIG. 2a is a schematic illustration plan view of a prior art baling machine during compression of the bale material;

(3) FIG. 2b is a schematic illustration plan view of the prior art baling machine after withdrawal of the plunger and prior to binding of the bale material;

(4) FIG. 3a is a schematic illustration of a prior art bale bound with baling twine, before the ends of the twine are tied;

(5) FIG. 3b is a schematic illustration of the prior art bale, after the ends of the baling twine are tied;

(6) FIG. 3c is a schematic illustration of the prior art bale after the bale has expanded, causing breakage of the baling twine;

(7) FIGS. 4a to d are schematic illustration of a baling machine according to an embodiment of the invention during closing of the twine loop;

(8) FIGS. 5 and 5b shows the device incorporated in the design of a baler.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

(9) The baling machine or baler shown in FIG. 1 includes a baling chamber 2 that is defined by top and bottom plates 3 and two side walls 4, one of which has been omitted from the drawing to show the interior of the chamber 2. The baling chamber 2 comprises a channel having an inlet end 6 and an outlet end 8. At the inlet end 6, the channel is closed by a plunger 10 that can be driven into the baling chamber 2 in a reciprocating manner. In this example, the plunger 10 is driven from a rotating drive axle 12 via a pair of drive arms 14, 16. The baling machine also includes a binding device 17, for example as described in U.S. Pat. No. 4,074,623, for binding the bale with binding twine.

(10) In addition, the baling machine includes a pick up mechanism A for picking up cut bale material (for example grass and straw) from the ground, a feed mechanism B for feeding the bale material into the baling chamber 2, a set of needles C for feeding binding twine through the baling chamber and a drive mechanism D for transmitting drive to the drive axle 12 from the drive output of a towing vehicle (not shown). These components are all conventional and so will not be described in detail.

(11) The prior art baling machine represented schematically in FIGS. 2a and 2b is substantially as described in U.S. Pat. No. 4,074,623, the contents of which are understood by a skilled person and incorporated herein by reference. The baling machine includes a baling chamber 2 that is defined by two side walls 4, as well as by top and bottom plates (not shown in FIGS. 2a and 2b, but denoted 3 in FIG. 1). The opposed side walls 4 are inclined towards one another to provide a tapered channel and can be adjusted to different degrees of taper. The baling chamber 2 thus consists of a channel having an inlet end 6 and an outlet end 8. At the inlet end 6, the channel is closed by a plunger 10 that can be driven into the baling chamber 2 in a reciprocating manner. In this example, the plunger 10 is driven from a rotating drive axle 12 via a pair of drive arms 14, 16.

(12) The baling machine of FIGS. 2a and 2b is shown in operation, containing within the baling chamber 2 a compressed but unbound body 18 of bale material and a compressed and bound bale 20. The completed bale 20 is bound with binding twine 22. In this example, five loops of binding twine 22 are used, which extend around the top, bottom, front and rear faces of the bale 20.

(13) In FIG. 2a the baling machine is shown during a compression stroke, in which the plunger 10 is driven forwards as depicted by arrows 24 into the baling chamber 2. As a result of this movement of the plunger 10, a body 18 of bale material that has been loaded into the baling chamber 2 is driven forwards within the baling chamber 2 against the end face of the already formed bale 20. The body 18 of bale material is thus compressed both longitudinally and transversely: longitudinal compression resulting from being pressed by the plunger 10 against the end face of the already formed bale 20 (and from the frictional forces acting on the bale 20), and transverse compression of the body 18 resulting from it being forced between the converging side walls 4. The frictional force on the body 18 of bale material can be regulated by adjusting the positions of the side walls 4 and/or the top and bottom plates as indicated by arrows 30.

(14) During compression, the front and rear faces 25a, 25b of the body 18 of bale material are driven forwards by the plunger 10 as depicted by the arrows 26, 28. The resulting compression of the bale material is indicated by diagonal arrows 32. This process is repeated until the body 18 of bale material has reached the required size.

(15) Once the body 18 of bale material has reached the required size, the bale material is bound with baling twine. A set of needles (not shown in FIGS. 2a and 2b, but denoted C in FIG. 1) carrying the binding twines are extended through slots 34 in the face of the plunger 10 and the twines 22 are then tied around the bale. The binding and knotting processes may for example be substantially as described in U.S. Pat. No. 4,074,623.

(16) After the bale material has been bound, the plunger 10 withdraws as illustrated by arrows 35 in FIG. 2b so that bale material for the next bale can be fed into the baling chamber. As the plunger withdraws, the rear face 25b of the body 18 of bale material recovers slightly and expands a short distance rearward as depicted by arrows 36. This rearward expansion of the body 18 of bale material is limited by the binding twines 22 that have been tied around the body 18 of bale material and increases the tension in the binding twines.

(17) The next bale is then formed by introducing bale material into the gap 37 between the plunger 10 and the rear face 25b of the bale that has just been formed, then compressing the material by reciprocating movement of the plunger 10. This process is repeated as necessary to increase the size of the compressed body of bale material. As the process is repeated, the bale 20 that has just been formed is pushed along the channel towards the downstream end 8 of the baling chamber 2, and the previously formed bale 20 is ejected from the downstream end of the baling chamber 2 onto the ground.

(18) When the bale 20 is ejected from the baling chamber the compressive forces acting on the front and rear faces of the bale are removed, allowing the bale 20 to expand against the tension of binding twines 22. The overall length of the bale 20 therefore increases slightly, the unexpanded size of the bale 20 being indicated by broken lines 38. This increases the tension in the twines 22. As a result of this partial decompression of the bale the load carried by the twines 22 as the bale is expelled from the baling chamber 2 is significantly less than the pressure that was applied to the bale material by the plunger 10 (for example about 0.22 bar as compared to a compacting pressure of 4-10 bar).

(19) The prior art binding process is illustrated again in FIGS. 3a to 3c. In FIG. 3a, the bale 20 is shown in a compressed state, with two twines 22a, 22b forming a loop around the bale. First ends of the twines have been tied together forming a first knot 40. The second ends 22a, 22b of the twines have not yet been tied together.

(20) In FIG. 3b the bale 20 is shown after the second ends of the twines 22a, 22b have been tied together forming a second knot 40. An extra length L of twine is required by the knotting device, which is released after the knot 40 has been tied. Therefore, when both ends of the twine are released from the knotting device the total length of the twine binding increases by L1+(L3L2), which slightly reduces the tension in the binding.

(21) When the bale 20 is ejected from the baling chamber, both ends of the bale expand by a distance e as shown in FIG. 3c, the original positions of the ends of the bale being depicted by broken lines 38. This causes the circumference of the bale to increase by a length of 4*e. If the increase in circumference is greater than the additional length of twine released by the knotting device, that is if 4*e>L1+(L3L2), the overall tension in the twine binding will increase, which may result in failure of the twine forming the binding at knot 40 or 40.

(22) As is shown in FIG. 2b the twines most to the side of the bale (referred to herein as outermost) have to withstand a bigger part of the expanding bale (Z+X) compared to the twine loops around the middle of the bale (2*Z). Therefore the tension of the outer twine loops tends to be higher than the inner twine loops. It is observed that when breakage of the twine loops occur that in most of the cases the most outer twines will break first. When the outer twines break the second-most outer twines will become the outer twines and will break subsequently.

(23) A schematic baling machine according to an embodiment of the invention is shown in FIGS. 4a and 4b. This machine is similar in many respects to the prior art machine shown in FIGS. 1, 2a and 2b and the foregoing description therefore applies in part also to this machine. As in the prior art machine, the side walls 4 (not shown in FIGS. 4a and 4b) include adjustable wall sections, each adjustable wall section being mounted for pivoting movement about a pivot joint at the upstream edge of the wall section. An adjuster device is connected to each wall, the adjuster device being operable to adjust the position of the wall and thereby to adjust the frictional force applied to the already-formed bale 20 as it moves through the baling chamber 2. Alternatively or in addition, the adjuster devices may be configured to adjust the positions of the top and/or bottom walls of the baling chamber. The adjuster devices may for example be hydraulically or electrically driven and are controlled by a control device, which can operate automatically or in response to control signals provided by the operator.

(24) According to the invention, a twine loop increasing roller/guide 41 is provided to be engageable with the outermost twine loops 22, where it can be either fixed or adjusted to a position that increases the twine loop length by causing the binding device at that location to spool out more twine to a desired length before a knot 40 is tied, compared to the innermost loops. FIGS. 4a to 4d show different possible positions so as to increase the loop length from nothing as shown in 4a to a maximum as shown in 4d. The roller may be fixed in any of the positions of FIGS. 4b to 4c or adjustable between these options. Meanwhile, twine loops on the inward part of the bale can be formed in a conventional manner where no additional length needs to be applied.

(25) Control over the twine loop length is preferably adjustable so as to adapt the process to the expansion properties of the bale material, where expansion affects mostly on the outermost sides. For relatively inelastic materials that expand only slightly after compaction (e.g. silage), the required increase will be small (e.g. FIG. 4b), whereas for more elastic materials that tend to expand a lot after compaction (e.g. dry straw and/or materials that are baled in very dry conditions) the required increase will be substantial (e.g. 5-10 cm at compression levels of 6-10 bar, e.g. 4c or 4d).

(26) FIGS. 5a and 5b illustrate a cross section of a loop extending mechanism according to the invention located at the outer edges of where a bale is to be formed. A roller 41 is arranged to move to a number of different positions 41, 41 which, in practice, causes more twine to be drawn from a spool (not shown) before a knot is tied to secure the twine about a circumference of the bale 20. As mentioned, the extent of the lengthened position is determined by the material or other environmental conditions either sensed automatically or activated by manual input settings.

(27) The configuration of the invention described is intended to extend the peripheral or outermost twine loops of the bale, compared to the inner twines (e.g. of the five twine loops 22 across the bale in the illustrated prior art FIG. 2, the outermost would amount to the first and fifth loops, whereas the third is the innermost), to the same extended length in order to account for additional compression at the outer sides. However, the invention could be configured to provide different twine loop lengths across the same bale if this were desirable. In other words a series of rollers 41 could move independently of one another. In the preferred form the outermost twine loops (on the left and right sides of the bale respectively) are adjusted to have greater loop length, but the next most outer twine loops (say the second and fourth loops referring to FIG. 2) could also be adjusted, perhaps to a lesser extent. Of course the same principle could be applied to balers with more than 3 twine loops.

(28) Although the description is based on a double tie knotter (knotting two knots 40 and 40 in the loop) the principle of adjustment of the twine loop length will also be effective on a single tie knotter baler (with only knot 40 in the loop).