Abstract:
The invention relates to an apparatus for measurement of the weight force of a bale of crop material after it is formed in a baler. The formed bale is movable in the baler by a conveying device and a weight force measurement device is provided for measuring a measurement parameter which is influenced by the weight force of the formed bale. The measurement device is set up so as to measure the weight force of the bale when the latter is resting on the conveying apparatus.

Description:
FIELD OF THE INVENTION 
   The invention relates to an apparatus for measurement of the weight force of a bale, in a machine for forming and/or processing of bales, wherewith the bale is movable within the machine by means of a conveying device, and wherewith a measurement device is provided for measuring a measurement parameter which is influenced by the weight force of the bale. 
   BACKGROUND OF THE INVENTION 
   In the state of the art, a number of apparatuses for measurement of the weight or mass of a bale comprised of pressed agricultural crop material are known. 
   For example (DE 44 36 128 A, DE 198 35 163 A, DE 199 10 555 A, U.S. Pat. No. 4,742,880 A, U.S. Pat. No. 5,384,436 A, and U.S. Pat. No. 5,742,010 A), it has been proposed to convey a fabricated bale out from the press chamber and onto a support surface, where the weight of the bale is measured while the bale is at rest or is moving, the measurement being a measurement of the force exerted on the support surface. Because a bale is relatively heavy, bringing it to a complete stop requires substantial effort. However, if one attempts to measure the weight force while the bale is moving, the process is subject to substantial measurement error. 
   In DE 195 43 343 A, it was proposed to measure the weight forces acting on the axles and the tow-bar of a baling press. The weight force of the fabricated bale is calculated based on the change in the forces when a bale is ejected. In order to obtain usable measurement values with this approach, a large number of sensors and a highly developed calculation scheme are required. 
   SUMMARY OF THE INVENTION 
   The underlying problem of the present invention is expressed as to devise a simple and reliable apparatus for measurement of the weight force of a bale, which apparatus does not have the abovementioned drawbacks or has them only to a lesser degree. 
   This problem is solved according to the invention by the provision of a machine for forming and/or processing bales and including a conveying device for conveying the bales. It is proposed that a measurement device be provided which measures the weight force of a bale disposed on the conveying apparatus. Thus, an already present conveying apparatus is utilized in the measurement of the weight force of the bale. The measurement device can be disposed at a relatively protected location in/on the machine. 
   The type of conveying apparatus may be arbitrarily selected. It may involve a carriage bearing a bale or bales, which carriage moves by its own drive means or via an external drive means, such as a linkage or rod. Or any other type of driven conveyor may be employed, which may have, e.g., a gripper, hook, conveyor belt, or conveyor rollers. The conveying apparatus may be actively driven, or conveying of the bales may occur solely via gravity if a sufficient height differential is provided. 
   Preferably, the conveying apparatus is supported by support elements, on a support means or support structure which is joined to the machine. The support elements move with the conveying apparatus along the support structure, e.g., via rolling means. The measurement device is disposed between the support structure and the machine proper, e.g., it is disposed on the frame or undercarriage of the machine. Accordingly, the measurement device produces information about the weight force of the conveying apparatus as well as the bale located on the conveying apparatus. The weight force of the conveying apparatus is known or can be measured. Thus, the weight force of the bale can be ascertained by suitable computation. It is advantageous that it is unnecessary for the measurement apparatus to move along with the conveying apparatus. This facilitates data transfer from the measurement apparatus to an evaluation, memory and/or display apparatus which evaluation, memory, and/or display apparatus does not move along with the conveying apparatus. 
   In a preferred embodiment, the support structure, or a partial region of the support structure which cooperates with the measurement device, extends over only a part of the region of movement of the conveying apparatus. The weight force of the conveying apparatus with the bale present on the conveying apparatus is thus measured during the conveying. The conveying apparatus can be stopped for the measurement or can continue in movement during the measurement. In another embodiment, the support structure extends over the entire region of movement of the conveying apparatus. 
   The measurement device can be set up to directly measure the weight force exerted by the conveying apparatus and the bale present thereon. For this purpose, force measurement cells may be provided on both ends of the support structure, or at any position between the ends. 
   Alternatively, the measurement device may measure the rotational moment generated by the conveying apparatus and the bale present on the conveying apparatus. For this purpose, the support structure may be swingably mounted to the machine so as to be swingable around a horizontal axis which as a rule extend transversely to the direction of travel and/or the direction of movement of the conveying apparatus. The measurement device is disposed at a distance from the swing axis, namely between the support structure and the machine frame. The measurement of the rotational moment allows reducing the number of force measurement cells employed. Thus, a single measurement cell can suffice, if the support elements on both sides of the conveying apparatus are rigidly interconnected. 
   Machines which can advantageously employ the inventive apparatus include machines for producing and/or processing of bales, such as a combination bale press and bale-wrapping machine. In such a machine, the conveying apparatus is set up so as to transport the bale from the press chamber in which the bale is formed to the wrapping position in which a wrapping is applied around the bale. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Three exemplary embodiments of the invention, which will be described in more detail herein below, are illustrated in the drawings. 
       FIG. 1  is a schematic left side view of a machine for the producing and wrapping of bales, which is provided with an inventive apparatus for measurement of the weight force of bales, wherein the conveying apparatus is in a position for receiving a bale. 
       FIG. 2  is a view of the machine according to  FIG. 1 , wherein the conveying apparatus is in a bale-wrapping position. 
       FIG. 3  is a cross section through the machine along the line  3 — 3  of  FIG. 1 , illustrating the support of the conveying apparatus on the frame of the machine. 
       FIG. 4  is a schematic side view of the support of the conveying apparatus on the frame of the machine, with a first embodiment of the measurement apparatus. 
       FIG. 5  is a schematic side view of the support of the conveying apparatus on the frame of the machine with a second embodiment of the measurement apparatus. 
       FIG. 6  is a perspective view of the support of the conveying apparatus on the frame of the machine, with a third embodiment of the measurement apparatus. 
       FIG. 7  is a cross section through the support according to  FIG. 6 , along line  7 — 7 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to  FIG. 1 , there is shown a machine  10  for the producing and wrapping of bales, which is comprised of a press  12  for forming large cylindrical bales and including an undercarriage  14 , which undercarriage  14  also bears a wrapping apparatus  16  for wrapping of cylindrical bales  18  with film material  20 . The undercarriage  14  has, on both sides of the machine  10 , two longitudinal beams  22  which extend in the direction of forward travel of the machine  10 . A tandem axle  24  is disposed in the forward region of the longitudinal beams  22 , which tandem axle is supported on a pair of front wheels  26  and a pair of rear wheels  28 . The machine  10  is connected to a tractor by a tow-bar  32  whereby the machine is pulled over a field. 
   The round bale press is of a construction which is per se known, and is capable of producing bales from agricultural crop material which is fed to the press  12  via a pick-up  30 . The round bale press  12  has a forward housing part  34  which is fixedly attached to the machine frame  14  and a rear housing part  38  which is swingable around an upper swing axis  36 . When the rear housing part  38  is in a lowered working position, it cooperates with the fixed housing part  34  to define a variable or constant press space (not illustrated) for producing large cylindrical bales. In  FIG. 1 , the rear housing part  38  is shown in its up-swung position for discharging a completed bale  18 . 
   The bale  18  produced by the round bale press  12  rolls backward, on suitable elements, from the forward housing part  34  and arrives at a conveying apparatus  40  which comprises a forward roll  42  and a rear roll  44  which support a plurality of side-by-side disposed conveyor belts  46 . The bale  18  rests on the belts  46 . The conveying apparatus  40  is movable as a whole between a bale-receiving position, shown in  FIG. 1 , and a bale-wrapping position, shown in  FIG. 2 . 
   When the bale  18 ′ is in the bale-wrapping position, shown in  FIG. 2 , it is rotated around its cylindrical axis  48  by means of the conveying apparatus  40 , by rotational driving of the rolls  42  and  44  by suitable motors, in a known fashion. In this way, the bale  18 ′ is wrapped with film  20  by means of a spool which is mounted on an arm  54  and is swingable, e.g., in an arc, around a vertical axis  50 . In order to prevent the film-wrapped bale  18 ′ from falling onto the ground from the relatively substantial height of the conveying apparatus  40  when it is released from the conveying apparatus, the bale  18 ′ is then rolled onto the ground via an off-rolling device  52 . When the rear housing part  38  of the baling press is being swung upward, the arm  54  is rotated rearward, as shown in  FIG. 1 , in order to be out of the way. 
   The manner of mounting of the conveying apparatus  40  on the longitudinal beams  22  is shown in detail in  FIG. 3 , which shows a cross section along line  3 — 3  of  FIG. 1 . The rolls  42  and  44  are rotatably mounted on support members  56  which extend parallel to the beams  22 . The two support members  56 ,  56  are joined together by cross beams (not shown), and bear four axles  58  (see also  FIGS. 4 and 5 ) which extend horizontally outward, which bear support elements in the form of rotatable wheels  60 . Alternatively, the support elements  60  can be rigidly fixed to the axles  58  which can in turn be rotatably connected to the support members  56 . On the internal sides of the longitudinal beams  22 , support structures  62  are mounted which have a high-angle profile. The support elements  60  roll on the support structures  62 . 
   The movement of the conveying apparatus  40  between the position illustrated in  FIG. 1  and that illustrated in  FIG. 2  can be accomplished by a hydraulic cylinder or another motor (neither is shown). For this purpose, one might consider a rotational drive for the support elements  60 . The rolls  42  and  44  can be driven by a hydraulic motor or the like mounted on the support members  56 . One might also consider embodiments of the machine  10  wherein it is unnecessary to have a rotary drive means for the rollers  42  and  44 . 
     FIG. 4  shows a first embodiment of a measurement device  64  for measuring the weight force (mass) of the bale  18 . The support structures  62  are divided into a forward partial region  70 , upstream of a middle partial region  72 , and a rearward partial region  74  downstream of the region  72 . The forward and rearward partial regions  70  and  74 , respectively, of the support structures  62  are rigidly attached to the longitudinal beams  22 . 
   The middle partial region  72  of the support structures  62  has a length which is slightly greater than the distance between the axles  58 , and on a first end, forward or rearward, is swingably mounted to the longitudinal beam  22  so as to be swingable around a swing axle  66  which extends horizontally, and perpendicularly to the direction of travel. Alternative, the middle partial region  72  may be freely movable. Via the measurement device  64 , the middle partial region  72  is supported against a console  68  which extends inwardly from the longitudinal beam  22 . When both support elements  60  of the conveying apparatus  40  are disposed over the support structures  62  of the middle partial region  72 , they exert a rotational moment on the support structures  62  which gives rise to a force in the measurement device  64  which is measured by the measurement device  64 , and the measurement signal is communicated to an evaluation device (not shown). By comparison with the measurement value of an empty conveying apparatus  40 , the weight force of the bale  18  can be ascertained. 
   The evaluation device can also receive a measurement value from a sensor which determines the position of the conveying apparatus  40  or which generates a signal when said apparatus  40  reaches a predetermined position, so as to provide information as to which position on the support structures  62  is being occupied by the conveying apparatus  40 . This information can also be deduced from the signals from the measurement device  64 . The conveying apparatus  40  can be stopped for measurement, wherewith in order to improve the measurement accuracy when the machine is traveling over uneven terrain the measurement values can be taken over a relatively long period of time and can be averaged. Alternatively, the conveying apparatus  40  can be continuously in motion, and measurement values taken versus time and stored, preferably in combination with the abovementioned information about the position of the conveying apparatus, can be used to computationally ascertain the weight force. In this manner, the weight force of the bale  18  is found. Preferably, the weight force value is displayed in the cabin of the tractor by display means, and is stored in a portable memory device. 
   The measurement device  64  may be disposed in a protective housing, along with the support means, bearings or the like, of the support structures  62  on the swing axle  66 , because these are all disposed relatively close to the swing axle  66 . In an alternative embodiment, the measurement device  64  may be disposed on the end of the support structures  62  which is away from the swing axle  66 . 
     FIG. 5  shows the mounting of the measurement device  64  in a different embodiment of the invention. Here the support structure  62  extends over the entire region of movement of the conveying apparatus  40 . The support structure  62 , at its forward or rearward end, is swingably attached to the longitudinal beams  22  so as to be swingable around the horizontal swing axle  66  which extends horizontally, and perpendicularly to the direction of travel. At its opposite end, or any other position along its length, the support structure  62  is disposed above and rests against the measurement device  64  and, in turn, the console  68  on the longitudinal beam  22 . In this embodiment as well, the measurement device  64  measures the rotational moment generated by the conveying apparatus  40  and the weight force of the bale  18 . Further evaluation can be carried out as described above relative to the previously described embodiment. 
   In the two described and illustrated embodiments, it is possible to have measurement devices  64  at both ends of the support structure or structures  62 , in order to measure the weight force, rather than the rotational moment, of the conveying apparatus  40  and the bale  18  disposed on the conveying apparatus. 
   Finally,  FIGS. 6 and 7  illustrate a third embodiment of the mounting of the measurement device  64 . The support structure  62  is swingably connected to the longitudinal beam  22  so as to be swingable around a horizontal swing axis  66 ′ which extends in the direction of travel, which is the longitudinal direction of the longitudinal beam  22 . The support structure  62  has a right angle configuration and has a lower horizontal shelf which extends inwardly from the longitudinal beam  22 , and further has a vertical leg which extends upward from the outer side of the horizontal shelf, which vertical leg in turn is swingably connected to the longitudinal beam  22  via connecting elements  76 ,  76  so as to be swingable around the swing axis  66 ′. The measurement device  64  is disposed between the vertical leg and the longitudinal beam  22 . The measurement device  64  measures the rotational moment which the conveying apparatus  40 , together with the carried bale  18 , exerts on the support structure  62 . The support structure  62  may extend over the entire length of the region of movement of the conveying apparatus  40 , or over a part of the region. 
   As a rule, support structures  62  having a measurement device  64  are disposed on the longitudinal beams  22  at both sides of the vehicle so as to be able to avoid measurement errors which occur as a result of the lateral suspension configurations. On might also consider mechanically interconnecting the support structures  62  on the two sides of the machine  10 , e.g., by a sufficiently wide lower crossbeam, which enables the conveying apparatus to be driven over the cross beam. With this arrangement, only a single measuring cell would be required for the measurement device  64 . Another means of minimizing measurement error would be to provide separate inclination sensors which function along the direction of travel and/or in the transverse direction. 
   Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.