Abstract:
Corn sterilizing machine of the type using rotary blades. The machine uses a castrating head in the form of a case enclosing a rotary blade. The front surface of the case has a slot allowing for the introduction of the panicle to be cut. Each one of the vertical edges of the slot has a pivotable shutter having two upper and lower ramps, respectively.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a corn sterilizing machine. 
     2. Description of Background and Relevant Information 
     When a farmer produces seed corn, it is usually obtained by hybridization of two varieties. 
     The rows of one variety are alternated with those of another variety which are to fertilize the first variety. 
     Therefore, it is essential to remove the male elements from the variety which is to be fertilized by the second variety. The male elements are situated in the upper part of the seedling and should be removed when they appear. 
     Until now, this &#34;castration&#34; has been performed manually. Recently, there has been use of machines comprising rotary knives with vertical axes which cut off the upper part of the plant carrying the male elements and which, therefore, work like a lawnmower. 
     Since the panicle that has the elements to be removed is usually interwoven with the upper leaves of the seedling, the current machines, because of the way they work, cut off an important part of the greenery, which greatly harms later development of the corn seedling. 
     SUMMARY OF THE INVENTION 
     The present invention, which presents a solution to this drawback, is noteworthy in that for each row of corn to be treated, it comprises a castrating head comprising a case open toward the front, enclosing a rotary blade whose axis is approximately perpendicular to the stem of the plant and extends toward the forward direction of the machine. The ends of the blade are bent in a right angle to form two knives which cut off the upper part of the plant in a transversal direction in the forward direction of the machine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics will become clearer from the following description with reference to the attached drawings, as an example only: 
     FIG. 1 is an elevational view of a castrating head according to the invention; 
     FIG. 2 is a left-hand view of FIG. 1; 
     FIG. 3 is a top view of FIG. 1; 
     FIG. 4 is a partial view in perspective showing one embodiment of a machine according to the invention; 
     FIG. 5 is a view along F of FIG. 4 showing the possible use of the machine on sloping terrain; 
     FIG. 6 is a top view of FIG. 5; 
     FIG. 7 is a partial view on a larger scale and in perspective showing details of the embodiment; 
     FIG. 8 is a partial view in cross section on a vertical plane passing through the axis of the rotary blade and showing the setting of the case. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In referring to the drawings, it can be seen that in its simplest form, each castrating head comprises a case 1, presenting on its front side 2 an opening 3, and enclosing a severing device in the form of a blade 4 mounted on a shaft 5 whose axis extends to the plane of the row to be treated approximately perpendicular to the stems of the corn seedlings M. 
     Blade 4 is bent in a right angle at its ends to form two knives 6. Its axis extends onto the plane of the row to be treated approximately perpendicular to the stems of corn. 
     The vertical edges of opening 3 each present a shutter in two parts 7a and 7b, each of which is substantially planar. Part 7b is fastened onto 7a which can pivot on an approximately vertical axis 26 and can be immobilized at the required angle by mechanism 27 as shown in FIGS. 1 and 2. 
     Shutter 7b which is approximately shaped like a triangle is arranged so that one of its sides is approximately vertical and is journalled about a substantially vertical axis at element 28 toward the lower end of this side on shutter 7a. 
     In this manner, the two other sides 8 and 9 form two adjustable upper and lower ramps respectively. 
     The function of ramps 8 is to straighten panicle P to be cut as well as the leaf in which it is located in order to facilitate their introduction into case 1. 
     On the other hand, the function of ramps 9 is to bend down the underlying leaves so that they will not enter the case. 
     It is thus possible to cut off the panicles comprising the male elements without altering in an undesirable manner the greenery of the corn seedling. 
     According to an embodiment particularly applicable to machines carried by a tractor equipped with a slope correction system, the heads are affixed on bars 10 joined by journalled links 11 between them. 
     Each one of bars 10 is supported by the end of a pair of arms 12 journalled by its other end on an upright 13 affixed to the tractor vehicle (not shown) and which is able to pivot on an approximately vertical plane because of the action of jack 14. 
     Each one of bars 10 can pivot by the interposition of a shaft 15 on a plane perpendicular to that formed by arm 12 and corresponding upright 13. 
     Therefore, as shown in FIG. 5, if the rows of corn to be treated are located on a slope, it is possible, by careful adjustment of the angle of arms 12, to keep all castrating heads approximately equidistant from the ground. As shown in FIGS. 4 and 7, a movable parallelogram linkage connecting assembly is formed by a pair of arms 12, a respective upright 13, and a relatively short arm 12a which is movable, while remaining substantially perpendicular to the ground. 
     The rotary driving of blades 4 is achieved by the interposition of a hydraulic motor 16 mounted at the end of one of shafts 5. The movement is transmitted to the other blades by belts, such as 17 (FIG. 4). 
     Each one of cases 1 is linked to guides 18 each supported by a shank 19 that can slide and be immobilized in a catch of holder 20 affixed to the case. 
     The function of these guides is to straighten the seedling, which would have pushed obliquely in its row on a transversal plane. This makes it possible to guarantee that it will be possible to introduce its panicle into slot 3 of the corresponding head. 
     Although the supporting rods 10 can be bent horizontally, it is essential that slots 3 of the heads remain vertical. 
     For this purpose, a further linkage assembly is provided. Each one of cases 1 can freely pivot around the axis of shaft 5 by the driving of the blade by the interposition of link 21, journalled at one of its ends onto the end of a clamp 22 of case 1, and at the other onto axis 23 parallel to shaft 5 and affixed to mobile side 12a of the deformable parallelogram comprising corresponding arms 12. 
     FIG. 8 is an example of a way to link case 1 to bar 10. Thus, shaft 5 extends through bearing 24 externally comprising a shoulder on which the rear side of case 1 is engaged, which is held by plate 25. 
     The present invention is, of course, not limited to the embodiment described and shown, but rather extends to all varying shapes and sizes.