A twine restrictor is disclosed having the advantages of simplicity and reliability. The twine restrictor is generally formed from solid or hollow stock. It is left free floating while being restrained sufficiently to avoid loss. Twine is passed over a substantially horizontal surface of a twine arm assembly and the twine restrictor is simply placed on the twine, providing a force up to a value equal to its weight on the twine. The twine restrictor is unaffixed and no springs are required.

TECHNICAL FIELD

The principles disclosed relate to improvements to round balers used for harvest of agricultural crops. More particularly, the invention relates to improved reliability of a mechanism that feeds and controls twine to a formed cylindrical bale for wrapping the bale. The invention further relates to a feed mechanism configured to minimize potential negative influences related to movement of the twine during the portion of the baling cycle when the bale is being formed, while the twine is being held in position, ready to wrap the bale.

BACKGROUND

Many mechanisms have been developed for wrapping bales with filament typically referred to as twine. The twine is held in a staging position while a bale is being formed. An end of the twine is positioned to engage the moving periphery of the formed bale. This engagement pulls the twine which subsequently wraps the bale.

Restricting or tensioning devices usually comprise a spring-loaded plate, wherein the twine is held under spring tension between the plate and another surface. Adjustments are required when changing twine types and as conditions change.

Meiers, in U.S. Pat. No. 4,502,646, discloses such a twine tensioning device comprising a plate held against the twine by a spring.

U.S. Pat. No. 5,215,006 by Jennings et al. is for a twine clamp used in large round balers. The clamp is not usually used for providing tension while the twine is feeding onto the bale, but Jennings et al. disclose that the clamp could be used thus. No details are included.

There is need, therefore, for a reliable, simple twine restrictor.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a twine restricting device with improved reliability for large round balers. An additional object of this invention is to provide a simple tensioning device having a minimum of moving parts. Still another object is to provide a method and apparatus for twine restricting not needing adjustment when using different styles or brands of twine.

To accomplish the aforementioned goals, twine strands are passed under a twine restrictor of a predetermined weight, to provide restriction to its travel. In an additional embodiment, the twine passes over the twine restrictor. Whether the twine passes over or under the twine restrictor, the path taken by the twine is sufficiently curved or bent so as to provide restriction to its travel.

The cross-sectional shape of the twine restrictor may be round, rectangular, octagonal, trapezoidal, or other suitable shape. The twine restrictor may be captive in a sufficiently enclosed framework so as to keep it engaged with the twine most of the time. In an additional embodiment, the twine restrictor may engage holes in the framework at the twine restrictor's ends, the holes being sufficiently large to allow the twine restrictor to be free-floating, yet held captive to avoid being lost.

For the purposes of the present disclosure, “free floating” shall be defined as unaffixed, that is, not bolted, screwed, clamped, etc. A free floating twine restrictor may be constrained so as to avoid being lost. Such a constraint may comprise an enclosure in which the twine restrictor is free floating, or the ends of the twine restrictor may engage oversized holes whereby the restrictor is constrained but free floating. In particular, a twine restrictor held in place with a bolt and spring and allowed to flex only with the spring is not free floating according to this definition.

The twine restrictor may be made from various materials and in various forms. That is, it may be made from solid steel bar stock, hollow stock, aluminum, or other materials or forms depending on the required weight. The present invention is not limited in material or form. Preferably, the twine restrictor will be made from a non-corrosive material or be coated with a plating that resists corrosion. Resistance to wear may also be an issue with some twines in some applications.

Typically, the twine restrictor of the present invention is located on an end of the twine arm assembly closest to the bale. However, the present invention is not limited to a particular location for the twine restrictor.

DETAILED DESCRIPTION

With reference now to the various figures in which identical elements are numbered identically throughout, a description of various exemplary aspects of the present invention will now be provided. The preferred embodiments are shown in the drawings and described with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the embodiments disclosed. Any references, herein, to directions will be determined by facing in the direction of travel of the baler during normal operation.

FIG. 1illustrates a schematic side view of the left side of one configuration of a round baler16, known as a variable chamber baler. The baler16is shown with a formed bale12, and illustrates the main functional components. In this type of baler, a number of bale forming belts20, of a known flat configuration, typically approximately one quarter to one half inch in thickness and four to fourteen inches in width, are routed over several belt rollers in fixed positions, including the rollers32,34,36,38,42,44,46and48. These fixed belt rollers32,34,36,38,42,44,46and48are supported by bearings mounted to a left side panel and to a right side panel for rotation so that the belts are able to move, rotating the forming bale12in the direction indicated by the arrow13. The panels are not shown, as many configurations of the panels are well known. The side panels are spaced apart by various components including the rollers32,34,36,38,42,44,46and48and a tongue66. The spacing between the side panels defines the width of the bale forming chamber and the length of the cylindrical bale12that that will be formed by the baler. The belts20are kept under tension by a belt tightener82, so that the belts20define a variable-sized bale chamber.

Another type of round baler, known as a fixed chamber baler, does not include the variable size bale chamber feature, and typically includes rolling elements that are in fixed positions to define a bale chamber of a fixed diameter. The present invention is useful for either fixed or variable chamber balers.

At least one of the fixed position rollers32,34,36,38,42,44,46and48of the baler16is powered by a drive system that includes a right-angle gearbox62connected at its input shaft to a driveline64. The gearbox62transfers power from a towing vehicle10through an output shaft to chains and sprockets that transfer power to the driven roller(s) and to the pickup80, which functions to lift crop material14from the ground and into engagement with a roller72, belts20, and a starter roller55which cooperate to form the crop material14into a cylindrical bale12enveloped by the belts20. The chains and sprockets are not illustrated.

Once a bale12has reached its desired size, a wrapping material is applied to the outer circumference of the bale12while still in the baler16. After the bale12is thus wrapped, a tailgate, which comprises a portion of the side panels and the rollers42,44, and46, will pivot around a tailgate pivot94, allowing the finished bale12to drop out of the baler16.

The known wrapping materials include either a filament, typically know as twine, made from either natural fibers or various types of plastic, and sheet-type netwrap, typically made of a type of plastic material. Twine is typically inserted into a crop inlet area90of the baler16by a mechanism100and applied in a spiral fashion by moving from one side panel across to the opposite side panel while the bale16is rotating. Sheet-type netwrap is known to be applied to the bale16by a netwrap mechanism18, as described in coassigned, copending patent application U.S. Ser. No. 10/719,460, herein incorporated by reference.

Twine is stored on both sides of the baler16, in a supply roll known as a twine ball92, typically with more than one twine ball92on each side of the baler16. The twine is routed from the twine ball92, along the front of the baler16to the twine mechanism, along a path generally labeled as96. There can be a single strand or multiple strands of twine routed from each side to the twine tie mechanism100. The twine routing is typically defined by tubes and other guides, which are not illustrated in this disclosure, and each strand of twine passes through a tension plate98, located near the twine ball. The tension plate98clamps the twine to ensure that the twine is under some tension as it passes along the path96.

The twine is routed to the twine tie mechanism100, illustrated inFIG. 2as located beneath the tongue66, including a drive assembly110, a twine arm assembly200and twine cutter assembly300.

The drive assembly110can be seen in more detail inFIG. 3, with the twine arm assembly200in a partially extended position, to include an actuator112connecting to a drive gear114which pivots about a first axis116. The drive gear114meshes with a driven gear204, which pivots about a second pivot axis206. The actuator112can extend to rotate the twine arm assembly200counter-clockwise, toward a fully extended position as illustrated inFIG. 5, or retract to rotate the twine arm assembly200clockwise towards the fully retracted position as illustrated inFIG. 4. In the fully retracted position the twine arm assembly200is positioned beneath the tongue66, cut-away inFIG. 4to better illustrate the twine cutter assembly300including a link302, a bracket304pivoting about an axis306, a twine knife308, and a reaction bracket310.

FIGS. 6aand6billustrate the twine arm assembly200and twine cutters of the present invention in more detail, with the twine arm assembly200in a position with the strands of twine96L and96R being pulled in a direction97by the bale inFIG. 6a. As the twine tie cycle reaches the end of the cycle the twine arm assembly200will move from left to right to a position where the twine is cut as shown inFIG. 6b, as happens when the twine arm assembly200activates the rod302which rotates the twine knife308into the path of the twine, pressing it against the reaction bracket310to guarantee the twine is cut.

FIGS. 6aand6bfurther illustrate the twine arm assembly200of the present invention to include a twine restrictor220, which is constructed of a round bar. The restrictor220is shown on top of the strands of twine96L and96R.FIG. 7further illustrates a right-side twine strand96R and left-side twine strand96L passing from a twine guide240, illustrated as a porcelain insulator, at a twine entry end212, near the driven gear204, to an exit end214. Each strand of twine96L and96R is selectively located in one of several alternative apertures in a guide block268at the exit end214, allowing control of the spacing between the strands of twine96L,96R as it is installed on the baler16.

Each strand of twine96L and96R passes under a restrictor220that is located near the exit end214. The twine arm assembly200is constructed in two parts; a bottom U-shaped channel216, and a top U-shaped cover218, as shown inFIG. 6a. To initially route the twine strands through the twine arm assembly200, preparing it to wrap a bale12, the top cover218is removed by the operator, and the twine strands routed from the twine entry end212to the exit end214, while the twine restrictor220is removed with the cover218. The operator will position the twine strands96R,96L to extend beyond the end of the twine arm assembly200to ensure proper (reliable) operation. Once the twine is properly positioned, the twine restrictor220is installed on top of the twine strands96R,96L, as illustrated inFIG. 7, with the cover218still removed. The twine restrictor220is supported by the top surface260of the U-channel216while being retained in that position by the sides262,264and a front side266, which is formed by the guide block268. The cover plate218will be secured to the U-channel216, as illustrated inFIG. 6a, to hold the twine restrictor220in place.FIG. 16illustrates an alternate embodiment where the twine restrictor228is longer than the width of the U-channel, and passes through oversized slots while roll pins229retain the twine restrictor228to the twine arm assembly200, even with the cover128removed. The apertures in the sides of the U-channel, not shown, will be sized such that the weight of the restrictor228is supported by the top surface260, or strands of twine96R,96L. The twine restrictor228, bearing on top of the twine strands, minimizes the possibility of undesirable movement of the twine strands, while the twine arm assembly200is held in the position under the tongue66, as shown inFIG. 4, while a bale12is being formed.

Once the bale12is formed, the twine arm assembly200is rotated, moving the exit end214towards the formed bale12, to initiate the wrapping process. As the exit end214reaches the formed bale12, the twine strands96R,96L that extend from the twine arm assembly200will be pulled into the baler16. The twine strands96R,96L will then be moving rapidly, causing the twine restrictor200to roll, while twine is being pulled from the supply balls92and through the twine tension plates98. At the end of the twine cycle the twine arm assembly200will be rotated to the position illustrated inFIG. 6b, where the twine96R,96L will be cut. The restrictor220of the present invention will restrict the twine's96R,96L tendency to snap back as the tension in the twine96R,96L is suddenly eliminated after it is cut. It will also again minimize the possibility of undesirable movement of the twine strands96R,96L, while the twine arm assembly200is held in the position under the tongue66.

In this manner the single element, twine restrictor220, is able to hold more than one strand of twine.FIG. 8illustrates the twine arm assembly200with four strands of twine, as would be possible by routing two strands96L1and96L2from the left side and two strands96R1and96R2from the right side.

FIG. 9illustrates a detailed side view of the exit end214of the twine arm assembly200with the bottom U-Shaped channel216supporting the twine restrictor220, positioned on top of the twine strands96L and96R. If the twine is not being pulled into the baler16, the weight of the twine restrictor220traps the twine and holds it in position. As the twine arm assembly200is extended into the baler16, to introduce the strand of twine so that the twine is pulled into the bale12in order to wrap the bale12, the twine restrictor220will continue to bear on the twine strands. As the twine moves, the roller will rotate, causing little drag. If a single twine restrictor220is not sufficient to hold the twine strands96R,96L, then a plurality of twine restrictors220may be utilized, as illustrated inFIG. 10. Other options are shown inFIG. 11, where the twine restrictor222is constructed from a shaft with an octagonal cross-section, andFIG. 12with a square cross section224.FIGS. 13 and 14illustrate restrictors226with trapezoidal cross-sections, providing a certain restriction to twine movement when installed in a first orientation as shown inFIG. 13, and a different restriction when installed in a second orientation as shown inFIG. 14. In certain cases, the system may function best when there is no added restriction, in which case the system of the present invention can easily be adapted as illustrated inFIG. 15, with the twine being routed on top of the restrictor220. The appropriate cross-section, or orientation of the twine restrictor and twine can be selected to provide a desired restriction to the movement of the twine strands96L and96R.

FIGS. 17aand17billustrate cross sections of twine restrictors220to show that the twine restrictors220may be fashioned from solid (FIG. 17a) or hollow (FIG. 17b) stock depending on weight requirements. Any of the embodiments of twine restrictors220,222,224,226,228shown herein may be constructed of solid or hollow stock. The present invention is not limited to a particular material from which the twine restrictor220is made.

With regard to the forgoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the size, shape and arrangement of the parts without departing from the scope of the present invention. The true scope and spirit of the invention are indicated by the broad meaning of the following claims.