Method and apparatus for forming and wrapping round bales

Abstract

An improved method and apparatus are provided for forming and individually wrapping round bales of high moisture forage within a bale forming chamber of a round baler. The bales are wrapped to cover their side surfaces and an outer peripheral portion of the ends of the bale with plastic, leaving an unwrapped central portion of the bale ends. The individually wrapped bales are placed adjacent each other end-to-end, such that the wrapped end surfaces of the individually wrapped bales are adjacent each other. By slamming the wrapped bales together end-to-end, the O-ring of plastic on each end of the bales will cooperate to form an air tight seal with an adjacent bale. In one embodiment, a baler is provided with a mechanism for altering the profile of the ends of the bale as it is being formed within the baler. The purpose of the altered profile is to let a wrapping material be brought down over the ends of the bale while the bale is rotating within the baler. In another embodiment, a baler is provided with retracting side walls to provide a space in which the wrapping material can be brought down over the ends of the bale within the bale forming chamber. The invention results in a high quality, inexpensive, convenient feed package for livestock.

Description

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to an improved method and apparatus for producing high moisture livestock feed (e.g., balage, haylage, silage, etc.) in a round bale. In particular, the present invention relates to a method and apparatus for forming and wrapping round bales of forage of suitable moisture content with a plastic wrap material while the bale is still in the bale forming chamber of a round baler.

[0004] 2. Description of the Related Art

[0005] There are many machines and methods for making balage from fresh cut forage. For example, balage is commonly formed in round (i.e., cylindrical-shaped) bales that are positioned end-to-end in long rows for storage. In the case of high moisture balage, the round bales are often covered with a plastic wrap to prevent spoilage and maintain high nutrient levels. An example of a conventional apparatus and process for applying a plastic cover to a round bale is described in the Applicant's prior U.S. Pat. No. 4,248,343.

[0006] There are many advantages of putting forage up in a high moisture state rather than waiting for the forage to dry. Some of these advantages include:

[0007] a. Forage can be cut at the proper stage of maturity when the nutrient levels are at their highest; one doesn't have to wait for “perfect” hay making weather.

[0008] b. When the forage is cut and on the ground, the risk time of getting the forage wet is cut from days for drying hay to hours for balage. Forage can be put up as balage within a moisture range of 25% up to 65% moisture. Dry hay should be baled when the moisture content is below 20%.

[0009] c. The forage put up as balage is much more palatable for the animals due to its high moisture content.

[0010] d. Nutritional quality is higher for balage. Handling dry hay (e.g., raking, baling, stacking, etc.) will cause dry leaves to shatter and fall to the ground. Most of the nutrition in the balage is in the leaves.

[0011] It can be readily seen that there are many advantages to harvesting forage in a timely manner and preserving the forage in a high moisture, airtight package, called balage. However, under the present methods being used, there are several disadvantages. These disadvantages include:

[0012] a. The present systems require multiple pieces of equipment resulting in a high machinery investment. Typically a baler, a wrapper and a special stacker are provided as separate implements. The present invention can eliminate the expensive wrapper implement by wrapping the bale in the baler.

[0013] b. Under the conventional methods, a bale has to be wrapped with twine or net wrap before it is discharged from the baler. The present invention wraps the bale with plastic in the baler, thereby saving money by eliminating the need for first wrapping the bales with twine or net wrap.

[0014] c. Under the conventional methods, a bale is formed in the baler, wrapped with twine or net, discharged from the baler, and then picked up to be wrapped by a separate bale wrapper. This requires additional time and expense. With the present invention, the finish wrap is put on right in the baler, resulting in substantial savings of time and expense.

[0015] d. A large percentage of the wrappers used on farms today are of the type known as “total wrap” bale wrappers. These wrappers rotate the bale horizontally as it is laying on its side. Plastic is played out onto the bale about halfway up and as the bale rotates end-to-end, it also is slowly rotated about its long axis. With total wrap bale wrappers, the plastic is applied in multiple (20+) layers to each end of the bale. This is a great waste of plastic as it usually takes only about 3 to 4 layers to achieve a proper seal.

[0016] e. These large individual bale wrappers can be very complex with remote-infrared controls and complex electronic sensors and control boxes. All of this means expensive repair and rapid depreciation and obsolescence.

[0017] In spite of these serious disadvantages, the practice of making balage is gaining in popularity. Accordingly, a simplified, time saving, effective method of forming, wrapping, and storing balage is needed.

SUMMARY OF THE INVENTION

[0018] The present invention provides a unique method of modifying the shape of a round bale as it is being formed in a round baler, and an apparatus to provide the modified shape. The invention further provides an improved method of forming a round bale, wrapping the bale with plastic in the bale forming chamber, and then stacking the bales very tightly together end-to-end. This improved method produces top quality balage while expending a minimum in labor effort and machinery investment. The bale forming apparatus can be provided as an after market attachment to many models and makes of popular round balers, or it can be incorporated into the original construction of the baler.

[0019] The special bale profile created by the bale forming apparatus of the present invention has two functions. One is to hold the bale centered in position in the baler to facilitate the wrapping of plastic roll material around the bale within the bale forming chamber of the baler. The second function of the special profile is to provide a step-in area on the outer radial circumference of the bale at the distal ends of the bale. This step-in from the usual profile can be, for example, about 12 inches radially and about 3 inches axially on each end of the bale. The purpose of this special profile is to allow a plastic dispensing and wrapping apparatus to wrap the bale around its circumference and to bring the wrap down on the ends of the bale. This special profile/step-in area will eliminate the scuffing and abrading of the plastic wrap as the bale is rotating in the bale forming chamber. When the bale has sufficient plastic wrap put on its surface, the baler chamber is opened up and the bale is discharged onto the ground. When the farmer removes these bales to the storage area and the bales are jammed together end-to-end in a row, the O-ring of plastic wrap on each end of the bale will form an air tight seal. The exposed ends of the row of bales can be wrapped by hand to complete the airtight package.

[0020] In a first embodiment, an apparatus for forming the step-in profile of the bale is provided. The apparatus has profiling plates that are hingeably attached to each interior side of the bale forming chamber. The profiling plates are moved inwardly only after an inner portion of the cylindrical-shaped bale is formed. The profiling plates forcibly engage and squeeze the ends of the forming bale and cause the last forage to be applied to the bale to be displaced in from the sides of the confining bale chamber. The profiling plates may be of such a shape and size as to form a variety of bale profiles. The step-in bale profile provides a space within the baler adjacent each end of the bale that allows wrapping an outer peripheral portion of each end of the bale with a plastic wrapping material within the bale chamber. The step-in bale profile also prevents the wrapping material at each end of the bale from being scuffed or torn while the bale is rotated within the bale forming chamber and when the bale is discharged from the baler.

[0021] In an alternative embodiment, the baler side wall is formed with a center circle and an outer ring about the center circle, both of which can be moved relative to the baler side wall. As the bale is being formed, both the center circle and the outer ring are moved into the bale chamber. When the bale is formed and ready for wrapping, the outer ring is moved away from the bale, leaving a gap between the bale and the outer ring. This gap provides a space within the baler that allows wrapping the outer peripheral portion of the bale with a plastic wrapping material within the bale chamber. This alternative embodiment provides a wrapped bale that has substantially flat end surfaces (i.e., no shoulders or step-in profiles).

[0022] Numerous other objects and advantages of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of the present invention, simply by way of illustration of one of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will become more clearly appreciated as the disclosure of the invention is made with reference to the accompanying drawings. In the drawings:

[0024] FIG. 1 is a cross section of a round baler having a bale profiler and bale wrapper according to the present invention.

[0025] FIG. 2 is a cutaway rear view of a portion of the round baler of FIG. 1, showing details of the bale wrapper.

[0026] FIG. 3 is a perspective view of a round baler, modified in accordance with the present invention, dropping a wrapped bale to the ground, with a tractor in the background pushing together individual bales to produce a row of bales.

[0027] FIG. 4 is a perspective view of individual wrapped bales being pushed together to form a seal between the individual bales.

[0028] FIG. 5 is a perspective view of a portion of the baler that forms the modified profile of the bale.

[0029] FIG. 6 is a side elevational view of an unwrapped bale having the profile formed by the baler of FIG. 1.

[0030] FIG. 7 is a plan view of a side wall of an alternative embodiment of a baler according to the present invention.

[0031] FIG. 8 is a cross-sectional view of the baler of FIG. 7, showing the baler in position to produce a bale.

[0032] FIG. 9 is a cross-sectional view similar to FIG. 8, but showing the baler in a position ready for wrapping.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033] A method and apparatus for forming and wrapping round bales according to a first embodiment of the present invention will now be described with reference to FIGS. 1 to 6 of the accompanying drawings.

[0034] A modified baler 5 according to the present invention is shown in FIGS. 1 to 3. A tractor T provides PTO power and pulls the baler 5 through the field to gather forage into the bale forming chamber 6 of the baler 5. The baler 5 includes a forward portion 7 and a rearward portion 9 pivotally connected to the forward portion 7. The forward and rearward portions 7 and 9 together define the bale forming chamber 6 in which a bale B is formed. The forward and rearward portions 7 and 9 of the baler 5 can be substantially similar in construction, for example, to respective portions of the baler disclosed in U.S. Pat. No. 4,910,949, which is incorporated herein by reference. However, the baler 5 includes a wrapping attachment 11 attached to the rearward portion 9. The wrapping attachment 11 carries a roll of plastic 12, so that the bale B can be wrapped in layers of plastic 13 within the bale chamber 6 immediately after the bale B is formed by the baler

[0035] As seen in FIG. 6, the bales B formed by the baler 5 are generally cylindrical in shape, and have an outer side surface SS and an end surface ES. The end surface ES includes an outer peripheral portion OP which is covered with plastic 13 by the wrapping attachment 11, and an inner portion IP which remains uncovered. The formed bale B is rotated about its longitudinal axis within the baler 5 as the bale B is formed and wrapped. As the bale B rotates, the wrapping attachment 11 fully covers the cylindrical side surface SS and the outer peripheral portion OP of the bale B with plastic 13, leaving a center portion IP of the end surface ES of the bale B uncovered or exposed.

[0036] To make the bale end surface profile shown in FIG. 6, the baler 5 includes a pair of profiling plates 31 (FIGS. 1 and 5) mounted on each side wall 8 of the forward portion 7 of the baler 5. The profiling plates 31 can be disc-shaped, or they can be in the shape of a flap, paddle, or any other suitable shape for engaging the ends of the bale B to form the desired profile as the bale B is being formed. The profiling plates 31 are mounted so that they may be moved into, and retracted from, the lower sides of the bale forming chamber 6 where the forage first enters the chamber 6. For example, each profiling plate 31 can be pivotably mounted on its front edge 33 to a respective side wall of the baler 5, and a suitable actuator 32, such as a hydraulic cylinder, can be provided to selectively pivot the profiling plate 31 and move the rear edge 34 of the profiling plate 31 into and out of the bale forming chamber 6. To give the bale B its desired shape, each plate 31 is moved from its retracted position (adjacent the frame side wall) into the lower sides of the bale chamber 6 during the last stages of bale formation. This produces the step-in profile at each end of the bale B, as shown in FIG. 6, thereby shaping the outer peripheral portion OP of the bale B to accommodate the over-the-end plastic wrap 13. The plates 31 are retracted out of the bale forming chamber 6 from their profiling position just before the plastic wrap 13 is applied to the bale B.

[0037] In the specific example shown in FIG. 1, the bale Br 5 has a lower drum roller 25 that supports the bale B during bale formation, and bale restrictor discs 26 located adjacent to and above each end of the lower drum roller 25. Notches 27 are formed in the rear sides of the bale restrictor discs 26, and hinges 28 are mounted to the respective side walls 8 of the baler 5 within each of the notches 27. The profiling plates 31 are pivotally mounted to the baler 5 at their front edges 33 by the hinges 28. The profiling plates 31 are selectively pivotable about the hinges 28 to move the rear edges 34 into and out of the bale forming chamber 6 by the hydraulic actuators 32 to form the desired step-in profile on the ends ES of the bale B as it is being formed.

[0038] The shape of the bale B is important to the bale forming and wrapping method of the first embodiment of the Applicant's invention. By shaping the bale B in the manner shown (i.e., with an axially inwardly offset outer peripheral portion OP of the end surface ES), the plastic 13 is allowed to come down over the outer peripheral portions OP of the bale B while the bale is still in the baler 5. The gap between the outer end surface ES of the bale B and the side wall 8 of the forward portion 7 of the baler 5 (which is effectively formed by the profiling plate 31) provides the area for the plastic wrap 13 to come down over the end of the bale B and prevents damage to the plastic wrap 13 that would otherwise be caused by rotation of the bale B against the fixed side wall 8 of the baler 5. When the wrapped bale B is ejected from the baler 5, it is ready to be stabbed in the open center portion IP by a bale spear 30 on a tractor T2 and moved to the bale storage area. There, it can be slammed into a long airtight row 17 where it will undergo anaerobic fermentation and become silage in 20 to 30 days.

[0039] As seen in FIGS. 3 and 4, the exposed ends IP of the wrapped bales B are protected by placing the bales B adjacent each other end-to-end, and by slamming one bale into a bale already positioned on the ground. When one bale B is slammed into an already positioned bale, a substantially airtight seal is formed between the peripheral portions OP of the end surface wrapping, which are placed in contact with each other. In this manner, a row 17 of wrapped bales is made. When a desired number of wrapped bales B1-Bn are lined up in a row 17, the outer ends 19 of the two end bales B1 and Bn (FIG. 3) are covered with plastic, for example, by stretching plastic by hand over the ends 19.

[0040] The effectiveness of this procedure is shown in FIG. 4. In FIG. 4, it can be seen that at the junction 21 between two adjacent bales B, the neighboring ends of the two bales are “muscled up” or bulged out, as at 23. This “muscling up” (which has been emphasized in FIG. 3) of the ends of the bales B due to the jamming or slamming of one bale into another, makes an airtight seal that is very effective in keeping the air from entering the wrapped bales. Hence, air is substantially prevented from reaching the interior of the balage row 17. In addition to creating an airtight seal between adjacent bales B, the jamming of one bale into the end of the balage row 17 compacts the bales B in the row 17 expelling air from the bales B. The expulsion of extra air from the bales B helps reduce the degradation of the balage in the row 17. Conventional wrapping systems are not as effective as the present invention in allowing air to be expelled from the row 17.

[0041] An alternative embodiment for creating a space within the bale forming chamber 6 to wrap the bale B is shown in FIGS. 7 to 9. In this embodiment, the baler side walls 61 are modified by dividing the side walls into an inner circle 65 and an outer ring 63 surrounding the inner circle 65. The outer ring 63 and inner circle 65 of the side walls 61 are moved axially relative to the bale B by respective outer and inner actuators 66 and 67, such as hydraulic cylinder actuators. When the bale B is forming, both the outer ring 63 and the inner circle 65 are extended to the inside of the baler chamber 6 by the actuators 66 and 67, as seen in FIG. 8, and the bale B is formed in a normal manner. When the bale B achieves a desired size and is ready for wrapping, the outer ring 63 is retracted by its actuators 66 and the inner circle 65 remains in place, as seen in FIG. 9.

[0042] In this embodiment, the bale B remains fully cylindrical (i.e., no profiling or projecting portions on the end wall as in the bale B of FIG. 6). However, by retracting the outer ring 63, a gap G is formed between the bale end surface ES and the wall 61 of the baler B to allow the wrapping 13 to come down over the ends of the bale B. After the bale B is wrapped in this manner, the inner circle 65 is retracted by its actuator 67 so that the wrapped bale can tumble out of the bale chamber 6 without scuffing or tearing the plastic wrap 13.

[0043] This embodiment does not alter the normal profile of the bale, and thus, makes it easier to obtain an airtight seal between adjacent bales. Additionally, because the bale B is completely supported in the bale chamber 6 by the outer rings 63 and inner circles 65 during bale formation, and by the inner circles 63 during bale wrapping, the bale B is more stable in the chamber.

[0044] The wrapping attachment 11 can be used with either of the bale forming arrangements described above. The wrapping attachment 11 includes a support mechanism 70 for rotatably supporting the roll of plastic 12, and an arrangement of actuators and sensors for controllably moving the plastic roll 12 from side-to-side to guide the plastic material 13 over the surface of the bale B during the wrapping process. The support mechanism 70 can be a threaded carrier 71 mounted on a threaded shaft 72 that can be selectively rotated to cause a linear movement of the carrier 71 from side-to-side.

[0045] Electric drive motors 73, 74 and clutches 75, 76 are connected to the threaded shaft 72 using suitable belts 77, 78 and pulleys 79-82 to rotate the threaded shaft 72 in the desired direction. Alternatively, traction wheels that follow the belts of the baler can be used to drive the threaded shaft 72. This would create a relationship between the speed of the bale rotation and the speed of the transverse motion of the roll of plastic, thereby maintaining a uniform application of the plastic 13 to the bale B.

[0046] First and second sensors 83, 84 are provided near each end of the threaded shaft 72 for detecting the extreme left and right positions of the plastic roll 12, and a third sensor 85 is provided to detect a center position of the plastic roll 12. A fourth sensor 86 detects a metal tag on the baler belt 87 to provide an input for a bale revolution counter 88. A fifth sensor 89 detects whether the plastic 13 is feeding through the passage 90 leading to the bale chamber 6.

[0047] In operation, the bale B is formed within the bale forming chamber 6 of the baler 5 according to the processes described above. Once the baler 5 detects that a full bale B has been formed, the baler 5 alerts the tractor operator who then stops the hay from going into the baler 5. The operator then initiates an automatic bale wrapping sequence. According to one example, the bale wrapping sequence is started by the drive rollers 91 rotating to feed the plastic wrap 13 into the passage 90. The jaws of a solenoid finger cutoff mechanism 92 are opened to clear the passage 90 leading to the bale chamber 6, and a blower 93 is activated to direct air past the plastic material 13 and into the bale chamber 6. The passage 90 leading to the bale chamber 6 is defined at its forward end by a curved lip 94 that guides the plastic material 13 and diverted air into the bale chamber 6. The plastic material 13 is then gripped between the bale B and the baler belts 87 and pulled into the chamber 6 as the bale B continues to rotate. At this point, the drive rollers 91 open up and the plastic 13 begins to wrap around the bale B as the bale rotates within the bale chamber 6. The plastic feeding sensor 89 goes positive and starts the bale revolution counter 88 using the fourth sensor 86, and the blower 93 turns off.

[0048] The bale revolution counter 88 counts one revolution of the bale B with the plastic 13 wrapped on it and a signal is sent to a first one of the electric drive clutches 75 to engage and rotate the threaded shaft 72 so that the threaded carrier 71 moves linearly along the shaft 72 in a first direction. When the first sensor 83 goes positive, indicating that the plastic roll 12 is at the extreme left position, the threaded shaft 72 is stopped and the bale B rotates a predetermined number of times (e.g., three) within the bale chamber 6, as detected by the bale revolution counter 88. A signal is then sent to a second one of the electric drive clutches 76 to engage and rotate the threaded shaft 72 in the other direction so that the threaded carrier 71 moves linearly along the shaft 72 in a second direction. When the second sensor 84 goes positive, indicating that the plastic roll 12 is at the extreme right position, the threaded shaft 72 is stopped and the bale B rotates a predetermined number of times (e.g., three). The first electric drive clutch 75 is then engaged again to cause the threaded carrier 71, and hence, the plastic roll 12, to move back to the center position. When the third sensor 85 detects that the plastic roll 12 is at its center position, the threaded shaft 72 is stopped and the solenoid finger cutoff mechanism 92 is activated to close and hold the plastic 13 as the rotating bale B continues to pull the plastic 13 and cause it to separate from the roll 12. The plastic wrap feeding sensor 89 then goes off because the plastic 13 is no longer feeding. This alerts the tractor operator that the bale B is wrapped and is ready for ejection from the baling chamber 6.

[0049] It will be appreciated that the present invention is not limited to the exact constructions that have been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope and spirit of the invention. For example, the wrapping mechanism can be positioned across the front side of the baler instead of the rear side, various other types of actuators can be used to move the plastic roll from side-to-side during the wrapping process, and different wrapping sequences can be used. It is intended that the scope of the invention be limited only by the appended claims.

Claims

1. A method of forming and wrapping cylindrical bales in a baler, the baler including a main frame and a cover, the main frame having side walls, the main frame and cover defining a bale chamber, the method comprising: forming a bale in the bale chamber, the bale having end surfaces; operating the baler such that at least a portion of the end surfaces are spaced from the main frame side walls; and wrapping the bale within the bale chamber with an airtight material such that the material covers the side surface of the bale and at least an outer peripheral portion of the end surfaces of the bale.

2. The method of forming and wrapping cylindrical bales as set forth in claim 1, wherein said operating step comprises operating the baler to form a step-in profile on the end surfaces of the bale within the bale chamber.

3. The method of forming and wrapping cylindrical bales as set forth in claim 1, wherein the baler includes a profiling plate which is selectively movable between a retracted position in which the profiling plate is substantially adjacent the main frame side wall and an extended position in which the profiling plate extends into the bale chamber; and wherein said operating step comprises moving the profiling plate from its retracted position to its extended position when the bale reaches a desired size.

4. The method of forming and wrapping cylindrical bales as set forth in claim 1, wherein said operating step comprises moving at least a portion of the main frame side walls away from the ends of the bale before wrapping the bale to facilitate bringing the airtight material down over the ends of the bale.

5. The method of forming and wrapping cylindrical bales as set forth in claim 1, wherein the baler main frame side walls each include a central area and a surrounding area, the surrounding area being movable axially relative to the central area between a first portion in which the surrounding area is substantially flush and coplanar with the central area and a second position in which the surrounding area is spaced axially outwardly of the central area; and said operating step comprises moving the surrounding area of each side wall from the first position to the second position after the bale is formed and before wrapping the bale.

6. The method of forming and wrapping cylindrical bales as set forth in claim 1, further comprising the steps of forming and wrapping a plurality of said cylindrical bales, and placing said plurality of bales end-to-end in a row such that a seal is formed between adjacent bales by the airtight material brought down over the ends of the bales.

7. The method of forming and wrapping cylindrical bales as set forth in claim 6, wherein said step of placing said bales comprises forcefully slamming one bale into a previously positioned bale.

8. The method of forming and wrapping cylindrical bales as set forth in claim 6, further comprising the step of applying wrapping material to the outer end surfaces of the bales on opposite ends of the row.

9. A method of forming a row of wrapped cylindrical bales, the bales having a side surface and opposed end surfaces, the method comprising: individually wrapping formed bales with an airtight material to fully cover the side surface of the bale and at least an outer peripheral portion of the opposed end surfaces of the bale; positioning a first wrapped bale on the ground; and placing a second wrapped bale adjacent to the first bale to form a row of bales, the second bale being positioned such that the end surfaces of the two bales are adjacent each other and form a substantially airtight seal between the two bales.

10. The method of forming a row of wrapped cylindrical bales as set forth in claim 9, wherein central portions of the end surfaces of the bale are not covered by wrapping material when the bale is wrapped.

11. The method of forming a row of wrapped cylindrical bales as set forth in claim 10, further comprising the step of applying a wrapping material to outer end surfaces of end bales of the row of bales after the row has been completed.

12. A baler for forming bales, the bales having a side surface and opposed end surfaces, the baler comprising: a main frame having side walls; a cover, the main frame and cover together defining a bale chamber; and an operating mechanism that creates a space between said side walls and at least an outer peripheral portion of each opposed end surface of a bale within the bale chamber.

13. The baler according to claim 12, further comprising a wrapping mechanism that wraps a bale within the bale chamber with an airtight wrapping material and brings the wrapping material down over the ends of the bale while the bale is rotating within the baler.

14. The baler according to claim 13, wherein said wrapping mechanism comprises a means for moving a roll of wrapping material from side-to-side across a width of the baler for wrapping a bale being rotated within the bale chamber.

15. The baler according to claim 12, wherein said operating mechanism comprises a profiling plate which is selectively movable between a retracted position in which the profiling plate is substantially adjacent the main frame side wall and an extended position in which the profiling plate extends into the bale chamber.

16. The baler according to claim 12, wherein said operating mechanism comprises a central area and a surrounding area provided on each of said main frame side walls, said surrounding area being movable axially relative to said central area between a first position in which the surrounding area is substantially flush and coplanar with the central area and a second position in which the surrounding area is spaced axially outwardly of the central area.

17. The baler according to claim 16, wherein said central area is movable axially between a first position in which the central area is substantially flush and coplanar with the surrounding area and a second position in which the central area is retracted axially outwardly from the bale chamber.