Round bale wrapping apparatus

Abstract: A round baler (10) having a tailgate (14), pivotally connected to a main frame (11), operative between a closed position during which a bale is being formed, and an open position during which a formed bale is being discharged. A sledge assembly (20), mounted on the main frame (11) for movement between a bale starting position and a full bale position, has at least two transverse cylindrical rolls (22, 23) mounted in spaced relationship along an arcuate path. An apron (32), supported along a continuous path on the main frame (11) and tailgate (14) by a plurality of rotatable guide members (33-36, 38, 43, 44), includes an inner course (c) that cooperates with the transverse rolls (22, 23) on the sledge assembly to define a bale forming chamber. The apron (32) is driven along a continuous path in the same direction as the outer surfaces of the transverse rolls. A dispensing assembly (51) dispenses wrapping material into the bale forming chamber between the adjacent outer surfaces of the transverse rolls (22, 23) for wrapping the cylindrical package of crop material. Resilient transverse flaps (62) extending from one of the transverse rolls intermittently contacts the wrapping material as it is being dispensed into the chamber.

Description: The present invention relates generally to agricultural baling machines and more particularly to a baler for producing cylindrical bales, commonly referred to as round bales, having improved wrapping apparatus for wrapping a cylindrical package of crop material formed in a bale forming chamber. Round balers generally have a bale forming chamber defined by a pair of opposing side walls associated with an array of side-by-side belts, transverse slats trained on chains, a plurality of transverse rolls or a combination of these various elements, e.g. rolls and belts. During field operation, windrowed crop material such as hay is picked up from the ground and fed in a continuous stream into a fixed or variable diameter chamber. The hay is rolled into a cylindrical package within the chamber, wrapped with twine, net or the like and ejected onto the ground for subsequent handling. US-A-5,289,672 and US-A-4,956,968 disclose one type prior art round baler of the general nature described above. In this particular type of baler an expandable chamber is defined by a pair of fixed sidewalls, and a plurality of side-by-side belts cooperating with a series of transverse rolls, mounted between a pair of pivotally mounted arms. This arrangement of rolls and arms is commonly referred to as a sledge assembly. The chamber includes an inlet opening in the front through which crop material is fed. Also included is a pair of take-up arms pivotally mounted on the main frame, between which arms a pair of guide rolls are journalled. A biasing force on the take-up arms urges the outer surfaces of the guide rolls against the belts to maintain tension and thereby prevent slack from occurring in the belts during expansion and contraction of the chamber. Density of the bale can be affected by varying the force on the take-up arms. Another type prior art round baler of the same general nature employs a plurality of transverse rollers to define a cylindrical bale forming chamber with a fixed diameter. Examples of this type baler are shown, US-A-4,604,848 and US-A-4,841,851. It should be noted that the latter patent shows additional embodiments wherein a fixed chamber is defined by means other than rolls, i.e. belts (Figure 7) or chains and slats (Figure 8). The present invention relates to a wrapping system for a round baler in which a cylindrical package of crop material is formed in a fixed or expanding chamber wherein one or more transverse forming rollers are employed. For example, the chamber could comprise fixed side walls and expandable transverse elements consisting of a combination of belts and rolls of the general nature described in US-A-5,289,672, cited above. This is one example of the many prior art patents assigned to New Holland North America, Inc., that disclose this type of expandable chamber round baler. It is not uncommon in prior art round balers having this general configuration to feed the wrapping material between a pair of transverse rollers. Alternatively, the chamber could comprise fixed side walls and transverse elements at fixed locations in a configuration of the general nature described in US-A-4,612,855, cited above. EP-A-0 807 380 discloses a round baler which is provided with a stripper roll at the end of a chains-and-slat conveyor. The stripper roll surface has ribs for engaging crop material which is conveyed thereto by this conveyor. A net dispensing system can insert a tail of net material through an aperture between the end of the conveyor end and the stripper roll, such that the surface of the rotating bale can grasp the net for wrapping it around the bale. During the insertion phase, the ribs on the rotating stripper roll can be of some assistance for guiding the net material into the baling chamber. However, because of their low height and their smooth metallic surface, the ribs have only limited capacity for pulling the wrapping material into the baling chamber. There is a need for a wrapping system for round balers that consistently introduces wrapping material to the periphery of the cylindrical package formed in the chamber regardless of whether the diameter of the chamber is fixed or variable, and regardless of the nature of the transverse wall, i.e. belts, rolls or chains. More particularly, there is a need for a system that consistently initiates the wrapping function. Such system contributes to improved performance and operability of round balers. Additionally, the features thereof should be consistent with lower manufacturing costs without detracting from simplicity of field operation and serviceability. According to the invention, there is provided a round baler for forming crop material into cylindrical bales, said baler having: a main frame; a pick-up attached to said main frame for picking up crop material from a field; a pair of side walls supported on said main frame; a plurality of conveying elements supported between said side walls and having a crop engaging surface for defining, together with said side walls, a bale forming chamber operable to receive crop material from said pick-up and to form said crop material into a cylindrical package; said conveying elements including at least one transverse roll mounted in spaced relationship from an adjacent conveying element, said roll having a generally cylindrical outer surface, extending transversely of said main frame; means for dispensing wrapping material from a supply of wrapping material into said chamber between said transverse roll and said adjacent conveying element for wrapping the outer surface of said cylindrical package of crop material to form a round bale of crop material;. and feed assist means extending from said transverse roll for intermittent contact with said wrapping material as it is being dispensed into said chamber under conditions where the outer surface of a cylindrical package of crop material is being wrapped in said chamber, characterized in that said feed assist means comprise at least one resilient flap extending from said transverse roll. The flaps facilitate the introduction of the wrapping material into the baling chamber. This is particularly advantageous in conditions where the wrapping material is being introduced between two surfaces which are moved in opposite directions, e.g. the upper portion of one transverse roll and the lower portion of a further transverse roll which is mounted above the first roll and which is rotated in the same sense. The assist means on the first roll assure that the friction forces of the lower roll, which are directed inwardly, prevail over the friction forces of the upper roll, which are directed outwardly. The feed assist means can be used advantageously for consistent introduction of all types of wrapping medium, be it net, webbing, plastic foil or twine. The use is not limited to a particular type of round baler, the invention can be used on balers having a fixed or variable diameter. In a simple, yet effective embodiment, the flap comprises a transverse resilient element, extending from the surface of the transverse roll. Means may be provided for holding the flap to extend rearwardly with respect to direction of travel of the roll surface. These means may comprise a rod affixed to the roll surface and a clamp holding the flap in the nip between the rod and the roll surface. The flaps do not need to extend over the full width of the roll. It suffices that the feed assist means are arranged adjacent the side walls on opposite ends of the roll. A baler in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross sectional diagrammatic side elevational view of a round baler in which the present invention is incorporated. The tailgate is in the closed position and the elements of the bale forming chamber are shown in their core starting condition. Figure 2, generally similar to Figure 1, is a cross sectional diagrammatic side elevational view of a round baler in which the tailgate is in the closed position and the elements of the bale forming chamber are shown in an intermediate bale forming condition. Figure 3, also generally similar to Figure 1, is a cross sectional diagrammatic side elevational view of a round baler in which the tailgate is in the closed position and the elements of the bale forming chamber are shown in the full bale condition. Figure 4, also a cross sectional diagrammatic side elevational view of a round baler, shows the tailgate in the open position and the elements of the bale forming chamber after a bale has been discharged. Figure 5 is a view showing in detail those elements depicted within rectangular outline "5" in Fig. 3. Figure 6 is a partial view taken along lines 6-6 of Figure 4, showing details of certain elements of the present invention. Figure 7 is a view taken along line 7-7 of Figure 6. Referring to the drawings for a detailed description of the preferred embodiment of the invention, Figure 1 shows the cross section of a round baler 10 of the type in which the present invention is readily embodied. Baler 10 has an expandable bale forming chamber defined in part by belts and rolls. This type of expandable chamber is disclosed in various prior art patents, e.g. US-A-4,956,968 mentioned above, which is hereby incorporated by reference. It should be noted that throughout this description the drawings are diagrammatic in nature to best show the elements of the baler in which the invention is embodied. To this end, in many instances only one element in a pair is shown, especially in those cases where identical elements exist, disposed on opposing sides of the baler, e.g. wheels. Baler 10 has a main frame 11, comprising a plurality of rigid structural elements including a pair of side walls 19 (only one shown). Main frame 11 is supported by a pair of wheels 12 (also only one shown). A forwardly mounted tongue 13, integral with main frame 11, provides for connection to a tractor. Pivotally connected to side walls 19 by a pair of stub shafts 15 (only one shown) is a tailgate 14 which is closed during bale formation. Tailgate 14 includes walls 19' coplanar with side walls 19. A pick-up 16, mounted on main frame 11, has a plurality of tines 17, the tips of which are movable along a predetermined path to lift crop material from the ground and deliver it rearwardly along a generally horizontal path toward a floor roll 18, rotatably mounted on main frame 11. An expandable chamber for forming bales is defined by side walls 19', 19, an apron 32, and a sledge assembly 20, operative between the inwardly facing surfaces of such walls. Sledge assembly 20 comprises a plurality of transversely extending rolls 21, 22, 23 journalled at their ends in a pair of spaced apart arms 24, one of which is shown. These arms are pivotally mounted on stub shafts 26 for providing movement of sledge assembly 20 from the bale starting position shown in Figure 1 through the partly full position shown in Figure 2 to the full bale position shown in Figure 3, and finally to the bale discharge position shown in Figure 4. Rolls 21, 22, 23 are driven in a counter-clockwise direction by conventional means (for example, chains and sprockets) coupled via an appropriate drive train to a drive shaft 28. A starter roll 30, located adjacent roll 23, is also driven counter-clockwise. Sledge assembly 20 includes a fourth roll, a freely rotatable idler roll 31 carried between arms 24, commonly referred to as a follower roll. Net wrapping apparatus, generally designated by reference numeral 29 in Figures 1-4, is mounted between walls 19 on main frame 11 and sledge assembly 20 forwardly of the bale forming chamber. Net is dispensed from a supply roll 50 to the chamber via an opening between rolls 22 and 23 in a manner described in detail below. Similar mechanisms for dispensing wrapping material are shown in US-A-4,956,968 and US-A-5,289,672, mentioned above. The bale forming chamber is further defined by the apron 32 comprising a plurality of laterally spaced side-by-side belts supported by guide rolls 33, 34, 35, rotatably mounted in tailgate 14, and roll 36, rotatably mounted on stationary arms 37, affixed to main frame 11. Apron 32 is also supported on a drive roll 38, mounted on main frame 11. Although apron 32 passes between roll 21 and follower roll 31, it is in engagement only with follower roll 31 and not roll 21. In addition to its bale forming function, roll 21 also serves to strip crop material from the belts, and is commonly referred to as a stripper roll. Suitable coupling means (not shown) connected to drive shaft 28 provide for rotation of drive roll 38. This causes movement of apron 32 along its varying paths in the directions indicated by the arrows in Figures 1, 2 and 3. An additional guide roll 40 in the main frame 11 ensures proper driving engagement between the surfaces of the belts of apron 32 and the surface of drive roll 38. A pair of take-up arms 41 (only one shown), integral with sledge assembly 20, are affixed to sledge arms 24 for movement between inner, intermediate, outer and bale discharge positions shown in Figures 1, 2, 3 and 4, respectively. Take-up arms 41, which carry additional guide rolls 43, 44 for supporting apron 32, are urged with sledge assembly 20 toward the innermost position (Figure 1), i.e. bale starting position, by tension spring 42, mounted between one of arms 41 and main frame 11 by bracket assembly 39, affixed to main frame 11. Spring 42, mounted outwardly from wall 19, is pivotally secured to arm 41 by journal means extending through access slot s in side wall 19. While one function of spring 42 is to return the sledge and take-up assemblies to the start position after a bale is discharged, another equally as important function is to provide a force on sledge assembly 20 that resists expansive forces on the chamber. When the elements of round baler 10 are disposed as shown in Figure 1, an inner course c of apron 32 extends between guide roll 35 and idler roll 31 to form the rear wall of the core starting chamber while the inwardly facing peripheral surfaces of rolls 21, 22, 23 define in a general manner a rearwardly inclined cooperating front wall. Floor roll 18 defines the bottom of the chamber and with starter roller 30 provides an inlet for crop material. When round baler 10 travels across a field, pick-up tines 17 lift crop material from the ground and deliver it through the inlet. The crop material is carried rearwardly by floor roll 18 into engagement with apron inner course c (Figure 1) which urges it upwardly and forwardly into engagement with the rolls on sledge 20. In this manner crop material is coiled in a clockwise direction to start a bale core. Continued feeding by pick-up tines 17 of crop material into the bale forming chamber in a generally spiral fashion causes the apron inner course c to expand in length around a portion of the circumference of the cylindrical package of crop material as its diameter increases (Figure 2). Take-up arms 41 rotate with sledge assembly 20 about the coaxial horizontal axes of stub shafts 26 from their initial positions shown in Figure 1 toward their outer positions shown in Figure 3 to provide for expansion of the inner course of the apron in a manner similar to that of the prior art balers mentioned above, i.e. in effect the outer course of the belts of apron 32 is diminished in length while the inner course increases a like amount. After a cylindrical package of crop material has been formed in the fashion described, it is wrapped by wrapping apparatus 29, utilizing either twine, plastic or net to encompass the package and form a round bale. Tailgate 14 is then opened and the completed bale is ejected rearwardly as shown in Figure 4. Subsequent closing of tailgate 14 returns the inner and outer courses of apron 32 to the locations shown in Figure 1. During bale formation, sledge assembly 20, along with the above described integral take-up assembly, moves between a bale starting position (Figure 1) to a full bale position (Figure 3). This movement of sledge assembly 20 causes idler roll 31 to move along a generally arcuate path while maintaining apron 32 in close proximity to roll 21, thereby allowing roll 21 to strip crop material from the belts and prevent or reduce significantly the loss of crop material through the space between roll 21 and apron 32 during formation of a bale. Sledge assembly 20 is pushed outwardly cowards its full bale position during bale formation as the crop material expands against rolls 21, 22, 23 and then subsequently is returned inwardly by apron 32 and spring 42 to the position shown in Figure 1. With the above description and general operation of baler 10 as a background, attention will now be directed to the wrapping system shown. As will become apparent, the wrapping apparatus of baler 10 is merely illustrative of one of the many types to which the features of the present invention are adaptable. For example, although a net wrapping system is shown, utilization of plastic wrap or twine would have no affect on the general aspects of the present invention. To further enhance understanding of the various features of the present invention, it should be noted that even though a unified sledge and take-up assembly is shown, the invention is equally adaptable to other types of round baler configurations having wrapping apparatus operative in the vicinity of a pair of transverse rolls defining a slot through which a wrapping medium is introduced, e.g. a variable diameter round baler in which the take-up arms and sledge are not integral, a round baler having a chamber with a fixed diameter, etc. Thus, the advantages realized by the present invention are not limited to a round baler with a particular fixed or variable chamber configuration. Now turning to Figures 5-7, with reference back to Figures 1-4, the wrapping apparatus 29 more particularly comprises a net insertion assembly 51 shown, firstly, in its inactive condition in Figure 1, under conditions where a bale core is being initiated in the chamber, secondly, while still in its inactive condition, it is shown in Figure 2 in the position it takes after the cylindrical package of crop material has reached the full chamber condition, and, lastly, net insertion assembly 51 is shown in the dispensing condition in Figure 3. Figure 4 shows the relationship of the various elements and assemblies of the baler after a cylindrical package of crop material has been wrapped and discharged rearwardly from the bale forming chamber. More particularly, Figures 1-4 show an active net roll 50 operatively mounted for dispensing net, via wrapping apparatus 29, along path p, i.e. around a guide roll 52 to a spreader roll 53 mounted between side walls 54 of net insertion assembly 51, to clamping members 55, 56 (descriptively referred to as the duckbill). The net is finally severed by shearbar 57 and knife 58, mounted on arm 60, in a manner known in the art, e.g. severing systems of this type are shown in US-A-5,289,672 and US-A-4,956,968, referred to above. For the purposes of this description, the tail of the net is shown in Figure 3 as being dispensed into the bale chamber via transverse clamping members 55, 56 of insertion assembly 51. A twine arm assembly, shown in US-A-5,581,973, is also adaptable for use with net insertion assembly 51. In this patent both twine and net wrapping systems are contemplated on the same baler, which is a fixed diameter chamber baler employing rolls in combination with chains and slats to define the chamber. Likewise, even though net wrapping is illustrated for the purposes of this description, the insertion of twine or plastic webbing into the bale forming chamber is also contemplated, i.e. the duckbill may be utilized to insert and dispense either net or twine into the chamber. To this end, reference is again made to US-A-5,581,973, which shows apparatus for wrapping with net and/or twine, albeit, the baler is a fixed chamber type machine. The crux of the present invention is to provide round baler wrapping apparatus with means that provide effective feeding of the wrapping material by engaging the material as the tail is being inserted into the bale forming chamber by the duckbill. This is accomplished in a round baler 10 having the same general configuration as the baler described in the above paragraphs wherein, as shown in Figures 5-7, the conveying means on the sledge assembly 20 comprise at least two transverse rolls 22, 23, each having a generally cylindrical outer surface. The rolls are mounted on the sledge assembly 20 in spaced relationship along an arcuate path, and means rotate the rolls 21-23 in a counter-clockwise direction (see arrows) such that the outer surfaces thereof move in the same direction of travel as the apron 32. The improvement comprises resilient means extending from the lower transverse roll, i.e. the pivot roll 23, for intermittent contact with the wrapping material, be it net, twine or plastic, as it is being dispensed into the chamber by clamping members 55, 56 of the duckbill of the insertion assembly 51, under conditions where a cylindrical package of crop material, formed in the chamber, is being rotated by the sledge rolls 21-23 and apron 32. The resilient means referred to above comprise a plurality of flaps 62 held in place on the opposing ends (see Figure 6) of the outer surface of roll 23 by clamps 63 and rods 64, the latter of which serves to hold flaps 62 in an outwardly extending posture. It should be noted that the lower clamping member 56 of the duckbill is inserted into the opening between transverse rolls 22, 23 such that it is disposed in operative relationship to the ends of flaps 62, whereby repeated positive engagement of flaps 62 with the tail, or tails, of the selected wrapping material being dispensed along path p is readily facilitated. In the case of net or plastic, the flaps 62 engage the wrapping material in the vicinity of both edges and urge it inwardly as the flaps continue to intermittently engage it during the wrapping process. Likewise, if the wrapping medium being used is twine, the flaps engage the twine as it is being initiated at the outer edges of the cylindrical package of crop material in the case of twin twine arms. The flaps can be positioned selectively along roll 23 to accommodate the position at which the twine arms initiate wrapping. It is also contemplated that the flaps could be continuous along the full width of roll 23 to more aggressively engage the wrapping medium, under conditions where desirable, e.g. when feeding plastic around crop material with a relatively high moisture content. Of the many implicit and explicit advantages of the present invention, one of the most important is the ability to function in a plurality of round baler configurations, i.e. rolls, belts and rolls, or even a chain and slat configuration, as long as the wrapping material is fed into the chamber through a transverse space between two adjacent bale forming elements, such as rolls or the equivalent thereof. Further, the chamber having a transverse space so defined, could be a fixed or variable diameter forming chamber machine, and the wrapping medium could be twine, net or plastic sheets or webbing.

Claims: A round baler (10) for forming crop material into cylindrical bales, said baler having: a main frame (11); a pick-up (16) attached to said main frame (11) for picking up crop material from a field; a pair of side walls (19, 19') supported on said main frame (11); a plurality of conveying elements (18, 21-23, 30, 32) supported between said side walls (19, 19') and having a crop engaging surface for defining, together with said side walls (19, 19'), a bale forming chamber operable to receive crop material from said pick-up (16) and to form said crop material into-a cylindrical package; said conveying elements including at least one transverse roll (23) mounted in spaced relationship from an adjacent conveying element (22), said roll (23) having a generally cylindrical outer surface, extending transversely of said main frame (11); means (51) for dispensing wrapping material from a supply (50) of wrapping material into said chamber between said transverse roll (23) and said adjacent conveying element (22) for wrapping the outer surface of said cylindrical package of crop material to form a round bale of crop material; and feed assist means (62-64) extending from said transverse roll (23) for intermittent contact with said wrapping material as it is being dispensed into said chamber under conditions where the outer surface of a cylindrical package of crop material is being wrapped in said chamber, characterized in that said feed assist means (62-64) comprise at least one resilient flap (62) extending from said transverse roll (23). A baler according to claim 1, characterized in that said at least one flap (62) comprises a transverse resilient element (62). A baler according to claim 2, characterized in that said feed assist means (62-64) comprise at least one pair of flaps (62), arranged adjacent said side walls (19) on opposite ends of said transverse roll (23). A round baler according to claim 2 or 3, characterized in that said feed assist means (62-64) further comprise means (63, 64) for securing said at least one flap (62) transversely along said one transverse roll (23). A round baler according to any of the claims 2 to 4, characterized in that said feed assist means (62-64) comprise means (63, 64) for holding said at least one flap (62) to extend rearwardly with respect to the direction of travel of the outer surface of said transverse roll (23) under conditions where said roll is rotating. A round baler according to any of the preceding claims, characterized in that it further comprises means for rotating said at least one transverse roll (23). A round baler according to any of the preceding claims, characterized in that said adjacent conveying element comprises a further transverse roll (22) mounted in spaced relationship to said transverse roll (23), said transverse rolls (22, 23) being arranged along an arcuate path. A round baler according to claim 7, when appended to claim 6, characterized in that said means for rotating are operable to rotate said rolls (22, 23) such that the outer surfaces thereof move in the same direction of travel. A round baler according to claim 7 or 8, characterized in that : said rolls (23, 23) are rotatably mounted in spaced adjacent relationship on a sledge assembly (20) mounted on said main frame (11) for movement between a bale starting position and a full bale position; and said plurality of conveying elements (18, 21-23, 30, 32) further includes an apron (32) supported along a continuous path by a plurality of rotatable guide members (33-36), said apron path having an inner course (c) that cooperates with said rolls (22, 23) on said sledge assembly (20) to define said bale forming chamber. A round baler according to any of the preceding claims, characterized in that said wrapping material comprises net.

Inventors: UNDERHILL KENNETH R, UNDERHILL, KENNETH R.
Applicants: CNH BELGIUM NV, CNH BELGIUM N.V.
Application year: 1999
Main classification: A01F15
IPC codes: A01F15