Abstract:
A machine for mowing stalk-type crops includes a crop conveyor wheel mounted for rotation about an approximately vertical axis and provided with recesses that are distributed over its circumference and designed as receptacles for plant stalks. A stationary shield is fixed directly above the conveyor wheel and includes an outer region located above an outer portion of the conveyor wheel just inwardly of the recesses of the surface of the conveyor wheel. In order to improve the crop transport and to prevent the loss of corn cobs, the shield is provided with an arcuate cutout located between the outer region and an inner region of the shield, the cutout having an open end located adjacent to the crop flow received by the machine.

Description:
This application is a divisional application of application Ser. No. 10/078,291, flied Feb. 19, 2002, now U.S. Pat. No. 6,588,190. 
    
    
     FIELD OF THE INVENTION 
     The invention pertains to a machine for mowing stalk-type crops which contains a conveyor wheel that can be put into rotation about an approximately vertical axis and which is provided with recesses distributed over its circumference and designed as receptacles for plant stalks, wherein a stationary shield that shields a region of the conveyor wheel surface is arranged above the conveyor wheel. 
     BACKGROUND OF THE INVENTION 
     A device for mowing stalk-type crops is known from U.S. Pat. No. 5,546,737. This device includes coaxially arranged cutting and conveyor wheels that rotate about an approximately vertical axis, with the conveyor wheels being above the cutting wheels and provided with a series of pocket-like recesses distributed over their circumference. The cutting wheels rotate and cut off the stalks of the plants to be harvested, for example corn stalks. The conveyor wheels that rotate in opposite directions transport the plants rearward in the pocket-like recesses. The plants are subsequently removed from the recesses by means of bow-shaped clearing devices arranged on the upper side of the conveyor wheels and transported to the feed rollers of a field chopper. In the intake region, the clearing devices are arranged at a distance from the pocket-like recesses, but extend outward to such an extent in the delivery region that they press the stalks out of the recesses. The cutting wheels are equipped with upwardly protruding ribs that serve for directing the cut plant stalks inward and holding said stalks within the effective range of the pocket-like recesses of the conveyor wheels. The conveyor wheels have a smooth upper side. Except for the clearing devices, the conveyor wheels are not provided with a shield. 
     Another mowing device is disclosed in GB 2 012 154 A. This mowing device is also composed of cutting wheels and conveyor wheels coaxially arranged above the cutting wheels. An upwardly open channel is defined by shields situated above, and adjacent to, the conveyor wheels. The upright plants are transported rearward through this channel and transported to the feed rollers of a field chopper. In one embodiment, the conveyor wheels are flat and provided with pocket-like recesses on the outer circumference. In another embodiment, the conveyor wheels contain prongs that are distributed over their circumference and that extend approximately in the radial direction, wherein said prongs are bent rearwardly, opposite to the direction of rotation, over approximately half their length. 
     A mowing device with a conveyor wheel that is provided with recesses and with a stationary shield that is arranged above the conveyor wheel is known from U.S. Pat. No. 5,852,922. In this case, it is proposed to open a depression in the shield when harvesting whole plant silage and to shield the depression when harvesting corn. 
     One disadvantage of the described mowing devices can be seen in the fact that plant parts accumulate on the shields of the conveyor wheels and are thus lost. If no shield is provided, corn cobs and other plant parts that drop from the plant, during the cutting process or transport, fall onto a conveyor wheel and are thrown to the ground by the rotating conveyor wheel, resulting in the crop parts being lost. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an improved machine for mowing stalk-crops, and more particularly there is provided an improved stationary, upper shield for a rotary crop conveyor that turns about an upright axis. 
     An object of the invention, is to provide an improved upper shield, as stated above, which is designed for reducing crop loss during harvesting. 
     A more specific object of the invention, is to provide an upper shield, as stated in the preceding object, which defines an opening between an outer forward region of the shield, which curves next to the roots of the gathering recesses located in the crop conveyor, and an inner region of the shield, which is mounted over a central part of the crop conveyor. 
     Yet another object of the invention is to provide an upper shield, as set forth in the immediately preceding object, wherein the opening is in communication with the feed path of the incoming crop material. 
     Still another object of the invention is to provide an upper shield for a rotary crop conveyor, where the shield is provided with a leading edge, as considered relative to the direction of rotation of the crop conveyor, to guide crop to the crop feed path. 
     Another object of the invention is to provide a crop conveyor having a plate-like upper conveyor section having an upper side that is provided with pocket-like recesses only in the edge region with at least one crop transport element that is designed for transporting away plant parts. In order to ensure that the transport element releases the entrained plant parts so as to re-introduce the plant parts into the crop flow, the invention proposes that the transport element have a rejecting transport behavior. For this purpose, the transport element may be arranged on the conveyor wheel at a trailing angle relative to the radial direction. 
     These and other objects will be evident from a reading of the ensuing description together with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The sole FIGURE is a somewhat schematic top view of a machine for mowing stalk-type crops and having stationary shields located over rotary crop conveyors and constructed in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, there is shown a machine for mowing stalk-type crops including a main frame  10  supporting right- and left-hand mowing and conveying or gathering devices  12  and  14 , respectively, as considered standing behind the machine and facing in the direction of forward movement V. The devices  12  and  14  are constructed in a conventional manner and include three disc-like conveyor wheels  16 ,  18 ,  20  that are spaced vertically, one from another and can be put into rotation about a common, approximately vertical axis by means of a drive. Each device  12  and  14  includes a cutting wheel, which is not shown in the figure in order to provide a better overview, mounted beneath, and for rotation together with, the wheels  16 ,  18 ,  20 . The circumference of the conveyor wheels  16 ,  18 ,  20  contains pocket-like recesses that serve for receiving plant stalks that are cut off by operation of the cutting wheels. The right-hand conveying and mowing device  12  rotates counterclockwise, while the left-hand conveying and mowing device  14  rotates clockwise, as indicated by the arrows. These conveying and mowing devices transport the cut plants rearward, opposite the forward driving direction V. The plants are then removed from the conveyor wheels  16 ,  18 ,  20  by means of suitable clearing devices (not shown in the figure) and drawn in by pre-compressing rollers  22  of a field chopper that carries the frame  10 . The frame  10  may also support more than the two conveying and mowing devices  12 ,  14  shown. When a plurality of conveying and mowing devices are arranged side by side, the lateral transport of the plants to the pre-compressing rollers  22  conventionally takes place along the rear wall of the frame  10  or by means of a screw. The conveyor wheels  16 ,  18 ,  20  and the cutting wheels are powered by the prime mover of the field chopper that transports the machine over a field in the forward driving direction V while harvesting. 
     A first shield  26  is connected to the frame  10  and is arranged above the top conveyor wheel  16  of the right-hand conveying and mowing device  12 . The shield  26  includes an inner shield region  27 , which shields a hub of the conveyor wheel  16  and includes an almost semi-circular edge  25 . The hub is supported on the inner shield region  27 . In addition, the shield  26  includes an arcuate outer shield region  30  arranged above the top conveyor wheel  16  on the front side of the conveying and mowing device  12 . The arcuate outer shield region  30  terminates at an end  36  situated above the side of the conveyor wheel  16  and includes an inner edge  31  disposed substantially concentric to the edge  25  of the inner shield region  27 . The inner shield region  27  and the outer shield region  30  are connected by a central shield region  28 . The central shield region  28  includes a leading edge  29  (relative to the direction of rotation of the conveyor wheel  16 ) which extends outwardly over the radial dimension of the conveyor wheel  16 , approximately tangentially from the inner shield region  27 . The leading edge  29  is slightly curved opposite to the direction of rotation of the conveyor wheel  16 . The inner shield region  27 , the central shield region  28  and the outer shield region  30  are realized integrally in the embodiment shown; however, they may also be realized in the form of discrete elements. 
     The inner shield region edge  25  and the inner edge  31  of the outer shield region  30  cooperate to define an upwardly open arcuate cutout  32  between the inner shield region  27  and the outer shield region  30  (above the parts of the conveyor wheel  16  which are not shielded by the central shield  28 ). This cutout  32  is concentric to the arcuate edge  25  of the inner shield region  26  and is open on its end that lies downstream as viewed in the direction of rotation of the conveyor wheels  16  and closed on the upstream end. A small vertical gap in which only a few plant parts can accumulate remains between the shield  26  and the upper side of the top conveyor wheel  16 . The shield regions  27 ,  28  and  30  are preferably curved or inclined in such a way that plant parts falling thereon are able to slide into the cutout  32 . 
     Similarly, a shield  26  is associated with the left-hand conveying and cutting device  14 , and includes an inner shield region  27 ′, an arcuate outer shield region  30 ′, and a central shield region  28 ′ that cooperate to define an arcuate, upwardly open cutout  32 ′ having a downstream end that is open in the direction of crop flow and a closed upstream end. 
     In the illustrated embodiment, the outer shield regions  30  and  30 ′ of the right-hand and left-hand conveying and mowing devices  12  and  14  are not realized symmetrically because the outer shield region  30 ′ of the left-hand conveying and mowing device  14  extends beyond the center of the feed channel, with the cutout  32 ′ extending around the inner shield region  27 ′ by an angle of approximately 200° while the central shield region  28  of the right conveying and mowing device  12  is smaller than the central shield region  28 ′ and is only mounted on a brace  34  that is directed in the forward moving direction V and connected to the frame  10 . The cutout  32 , defined by the outer shield  30  and inner shield region  27 , only surrounds the inner shield region  27  by approximately 60°. However, it would also be conceivable to realize the shields symmetrically. 
     Two transport elements  24  which are arranged diametrically opposite each other and are realized in the form of upwardly protruding ribs, are respectively arranged on the upper side of each top conveyor wheel  16 . These transport elements  24  are arranged in trailing fashion relative to the radius of the conveyor wheels  16  by an angle of approximately 60°. Thus, the transport elements  24  have a rejecting transport behavior. The transport elements  24  extend linearly from the outer edge of a hub  26  of the conveyor wheels  16  to almost the outer edge of the conveyor wheels  16 . The radial dimensions of the cutouts  32  and  32 ′ correspond to the radial dimensions of the transport elements  24 . 
     The feed and mowing devices  12 ,  14  according to the invention function in such a way that the cutting wheels cut off the plant stalks. The conveyor wheels  16 ,  18 ,  20  receive the plant stalks in the pocket-like recesses distributed over their circumference and transport the plant stalks to the feed rollers  22 . If corn cobs or other plant parts fall off, they either drop directly into the cutouts  32 ,  32 ′ or onto the shield regions  27 - 27 ′,  28 - 28 ′,  30 - 30 ′, and from there they slide into the cutouts  32 ,  32 ′. The surface of each of the conveyor wheels  16  then transports the plant parts to the feed rollers  22  with the aid of the transport elements  24 . The outer shield regions  30 ,  30 ′ guide the plant parts in the cutouts  32 ,  32 ′ and prevent them from being thrown off the conveyor wheel  16  before their re-introduction into the crop flow. Due to the rejecting transport behavior of the transport elements  24 , the plant parts are thrown off the conveyor wheels  16  on the downstream ends  36 ,  36 ′ of the outer shield regions  30 ,  30 ′ and entrained by the flow of harvested plants. Plant parts that might remain on the conveyor wheels  16  are transported outwardly by the leading edges  29 ,  29 ′ of the central shield regions  28 ,  28 ′, which act as clearing devices and respectively extend from the inner shield regions  27  up to the pocket-like recesses on the edge of the conveyor wheels  16 . These plant parts are then dropped into the flow of harvested plants by the conveyor wheels  16  and can be transported to the pre-compressing rollers  22  and the field chopper. 
     The measures according to the invention result in a machine for mowing stalk-type crops with which the crop transport can be improved. The machine can also be used for harvesting whole plant silage or storage corn without requiring modifications. 
     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.