Abstract:
A kernel processor includes a pair of rollers which are controlled such that the spacing between them varies inversely, or such that the contact pressure between them varies directly, in response to varying moisture content of the crop material being processed.

Description:
FIELD OF THE INVENTION 
     The invention concerns an apparatus for adjusting the spacing and/or contact pressure between two rollers of a kernel processor. 
     BACKGROUND OF THE INVENTION 
     In the current state of the technology, the rollers of a kernel processor can be positioned mechanically with a defined spacing between them. Upon the introduction of a foreign object, a roller, or both rollers, can yield along a fixed path under the force of a spring. Thus, the problem is posed of how to adjust the spacing between the rollers of the kernel processor. If a small spacing is selected, a true crushing of the grains contained in the harvested material is certainly guaranteed; however, in comparison to rollers which are adjusted to a larger spacing, the rate of feed is reduced and the energy requirement for the operation of the kernel processor device is increased. By increasing the spacing between the rollers, these disadvantages can be avoided; however, there is not an adequately assured crushing of the grains with moist harvested materials due to their relatively greater elasticity compared to dry harvested materials. Livestock that is then fed with this harvested material cannot completely digest it. 
     In DE 195 39 143 A, an intake device for forage harvesters is described, which is equipped with a device for the regulation of the pressure exerted on a vertically moving feed roller. The pressure operating on the harvested material which has been transported between the feed rollers is adjustable by this means. The pressure can also be controlled as a function of the throughput of the harvested material. 
     The problem that is the basis for the invention is how to achieve a true crushing of the kernels contained in the harvested material. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided an improved kernel processor arrangement. 
     An object of the invention is to provide a kernel processor capable of effectively crushing the kernels of harvested crop of varying moisture content. 
     A more specific object of the invention is to provide a kernel processor having a power-adjusted processor roll, wherein the actuator is coupled in a control system that monitors the moisture content of the harvested crop and sends a corresponding signal to control the processor roll actuator. 
     These and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left side schematic view of a forage harvester equipped with a kernel processor. 
     FIG. 2 is a schematic view of the system for controlling the spacing between the processor rolls. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A harvester  10 , shown in FIG. 1, is a self-propelled forage harvester including a chassis  12 , which is supported by front and rear sets of wheels  14  and  16 , respectively. The operation of the harvester  10  takes place from an operator&#39;s cab, from which a crop intake apparatus  20  is observable. Material taken up off the ground by the means of the crop intake apparatus  20 , for example corn, grass, or the like, is fed into a chopper or cutter drum  22 , which chops it into small pieces and releases it into a conveyor system  24 . The material exits from the harvester  10  through a pivoting discharge spout  26  to a following trailer. 
     Between the chopper or cutter drum  22  and the conveyor system  24 , a kernel processor with two interacting rollers  28  is installed, so as to receive the chopped material as it exits tangentially from the cutter drum  22  and is delivered tangentially to the conveyor system  24 . The rollers  28  of the kernel processor are driven in opposite directions. The flow of the chopped material is passed between them. The purpose of the rollers  28  is to crush or grind the kernels, especially corn kernels, of the harvested material so that they can be digested by livestock that is fed the chopped material. The outer surfaces of the rollers  28  of the kernel processor can be smooth or profiled in the standard manner. 
     The spacing of the rollers  28  of the kernel processor is controlled by a control device  44  (FIG. 2) as a function of the moisture of the material fed in. The underlying idea is that the kernels contained in the material are harder to grind, the moister the material is, since the grains then become more elastic. For dry material, larger spacing between the rollers is adjusted by the control device than for moist material. In this way, the increased energy requirement for the operation of the kernel processor associated with a relatively small opening can be avoided with dry material, which requirement is greater than with a large opening or a manual adjustment of the spacing between the rollers  28 . 
     The moisture of the material is measured by a moisture sensor, which in the example depicted is based on a microwave transmitter  32  and a microwave receiver  30 . The moisture sensor operates by transmission, that is, the material is irradiated, and it is positioned in the discharge spout  26 . More specific details concerning the construction and function of the moisture sensor are published in DE 196 48 126 A, the theory of which is incorporated by reference into the present application. 
     The moisture sensor is connected to the control device  44  by wiring. The control unit  44  electromagnetically controls a valve  40 , which is connected to a sump  42  and a hydraulic cylinder  38  by hydraulic lines with a source P of pressurized hydraulic fluid. The ram of the hydraulic cylinder  38  is mechanically attached to a rocker arm  34 , while its housing is supported by the chassis  12 , of the harvester  10 . The rocker arm  34  can be pivoted at one end about a rotational axis  48  located on the chassis  12  of the harvester  10 . On the other end of the rocker arm  34 , the upper roller  28  is positioned. The lower roller  28  of the kernel processor is, on the other hand, located in a fixed position. The upper roller  28  can be brought closer to the lower roller  28  by pressurization of the hydraulic cylinder  38 . The ram of the hydraulic cylinder  38  works against the force of a spring  36  connected to the rocker arm  34 . If the hydraulic cylinder  38  is separated from the source P, the spring  36  pulls the rocker arm  34  up, thereby pulling up the upper roller  28 , so that the spacing between the rollers  28  is increased. The hydraulic fluid which then flows out of the hydraulic cylinder  38  is conveyed across the valve  40  to the sump  42 . The upper roller  28  is attached at its other end to a second rocker arm corresponding to that shown in FIG.  2 . The second rocker arm is preferably pivoted by a hydraulic cylinder attached to it. 
     In order to make it possible for the rollers  28  to yield in case a foreign object Id pass between them, the housing of the hydraulic cylinder  38  can be supported over a corresponding spring on the chassis  12 . It is also conceivable to cushion it hydraulically, that is to connect the ram pressure compartment to a corresponding pressure accumulator. 
     The rocker arm  34  is also connected to a position sensor  46  in the form of a potentiometer adjusted by the rocker arm  34 , which provides an output signal that contains data about the current position of the rocker arm  34 . The position sensor  46  could also be installed inside the housing of the hydraulic cylinder  38 . The output signal of the position sensor  46  is transmitted to the control device. It makes it possible for the control device  44  to adjust the valve  40  in such a way that the upper roller  28  is moved into its required position. The control device  44  is adjusted as a result of the adjustment of the position of the upper roller  28  and consequently the size of the opening between the rollers  28 . 
     The control device  44  controls the size of the opening between the rollers  28 , as described above, as a function of the moisture of the harvested material as measured by the moisture sensor. In addition, a relationship is stored in memory in the control unit between the moisture and the spacing between the rollers  28 , for example in the form of a table, a database, or as a mathematical function. In special circumstances, the automatic control of the spacing between the rollers  28  can be switched off by an operator in the cab and be substituted by a manual adjustment of the size of the opening. 
     It is to be noted that various modifications of the invention are conceivable. For example, it would be conceivable to use another preferred moisture sensor instead of the microwave sensor, for example, a capacitive sensor, an optical sensor, or a conductivity sensor. The moisture sensor can also be installed in a location on the harvester  10  between the chopper drum  22  and the live ring of the discharge spout  26  or upstream of the chopper drum  22 . 
     Instead of a pivoting rocker arm  34 , the upper roller  28  can also be attached to a displaceable device, as described in DE 195 39 143 A. It would also be possible to move the lower and not the upper roller, or to move both rollers. 
     It would also be possible to use a different hydraulic control for the movable roller  28 . For example, the control of the feed rollers described in DE 195 39 143 A, the theory of which is incorporated by reference into this application, which makes a selectable pressure possible, can be adapted to the rollers  28  of the kernel processor. In this instance, it would not be the spacing of the rollers  28  that is adjusted, but rather the contact pressure of one roller  28  on the other roller  28  would be adjusted by the control device  44  as a function of the moisture of the harvested material. 
     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.