Sickle Cutter System

Abstract

In a sickle cutting system, it has been found that a significant reduction in average stubble length, which is calculated based on the distance crop is pushed forwardly without cutting occurring, can be obtained by a combination of the features where the length of the cutting edge of each knife blade from a transverse rearmost cutting line at which a cutting action occurs is increased to a length greater than 2.2 inches; the width at the rear of the ledger surface of each guard is increased to greater than 1.2 inches; and the front edge of the blade is formed with an apex to shed crop material to one or other side of the apex.

1 . A sickle cutting apparatus comprising:
 a frame structure arranged for forward travel over ground having a standing crop thereon;   a cutter bar secured to the frame structure and extending transversely across a front end of said frame structure;   a plurality of knife guards mounted along the cutter bar and projecting forwardly therefrom;   each of said guards having at least one guard finger so that the fingers are arranged in a row along the cutter bar with a space between each finger and the next allowing crop to enter the space up to a position of engagement with a surface of the guard;   each guard finger having an upwardly facing ledger surface with opposed side edges thereof arranged to provide first and second shearing edges;   a sickle bar mounted in transversely extending position and being driven for reciprocating movement relative to said guard fingers;   the sickle bar having a plurality of the sickle knife blades mounted thereon for movement therewith;   each sickle knife blade comprising a blade body having a cutting surface for passing across the ledger surface of the knife guard fingers and an opposed surface with the blade body having on first and second sides first and second side cutting edges to cooperate with said shearing edges of said guard fingers;   wherein cooperation between the blade and the ledger surface of the guard length defines a transverse rearmost cutting line at which a cutting action occurs;   wherein a length of each knife blade from the transverse line to a forwardmost tip of the knife blade is greater than 2.2 inches;   and wherein a width of each guard at the transverse line is greater than 1.2 inches.   
     
     
         2 . The sickle cutting apparatus according to  claim 1  wherein a center line spacing between each knife blade and the next is less than 3.0 inches and a length of each knife blade from the transverse line to a forwardmost tip of the knife blade is greater than 2.5 inches. 
     
     
         3 . The sickle cutting apparatus according to  claim 1  wherein the length of each blade from the transverse line to the forwardmost tip of the knife blade is greater than 2.5 inches. 
     
     
         4 . The sickle cutting apparatus according to  claim 1  wherein the length of each blade from the transverse line to the forwardmost tip of the knife blade is greater than 2.75 inches. 
     
     
         5 . The sickle cutting apparatus according to  claim 1  wherein the length of each blade from the transverse line to the forwardmost tip of the knife blade lies in the range 2.2 to 3.0 inches. 
     
     
         6 . The sickle cutting apparatus according to  claim 1  wherein a width of each guard at the transverse line is equal to or greater than 1.5 inches. 
     
     
         7 . The sickle cutting apparatus according to  claim 1  wherein a width of each guard at the transverse line is of the order of 1.75 inches. 
     
     
         8 . The sickle cutting apparatus according to  claim 1  wherein the transverse line is defined by a trash bar attached to the guard finger and extending outwardly to the sides thereof. 
     
     
         9 . The sickle cutting apparatus according to  claim 1  wherein a stroke length of the reciprocating movement is equal to the center line spacing between the knife blades. 
     
     
         10 . The sickle cutting apparatus according to  claim 1  wherein each knife blade has a front point portion in front of the side cutting edges which front point portion has side edges converging to front apex, where the apex and the side edges of the front point portion are shaped and arranged such that crop material engaging the front point portion, as the point portion is moved forwardly in the crop, is shed to one or other side of the front point portion for cutting by the side cutting edges and is not pushed forwardly by the front point portion. 
     
     
         11 . The sickle cutting apparatus according to  claim 10  wherein each side cutting edge is beveled from the opposed surface to the cutting surface of the knife blade defining a cutting edge at the cutting surface; the blade having a front point portion in front of the beveled side cutting surfaces; wherein the front point portion has side surfaces of the front point portion converging to a front apex of the front point portion having an apex surface generally at right angles to the cutting surface and the opposed surface and wherein the apex surface of the front point portion is not beveled with the thickness of the plate at the front apex of the front point portion being equal to said constant thickness. 
     
     
         12 . The sickle cutting apparatus according to  claim 11  wherein the beveled side surfaces are serrated in a direction generally at right angles to the center line. 
     
     
         13 . The sickle cutting apparatus according to  claim 12  wherein the beveled and serrated side surfaces terminate at a position spaced from the front apex of the front point portion such that the side surfaces of the front point portion are not serrated. 
     
     
         14 . The sickle cutting apparatus according to  claim 10  wherein the side surfaces and the front apex of the front point portion are curved around an axis on the center line at right angles to the plate. 
     
     
         15 . The sickle cutting apparatus according to  claim 10  wherein the front apex has a width less than 0.3 inch. 
     
     
         16 . The sickle cutting apparatus according to  claim 1  wherein each knife guard comprises a stub guard with a lower member defining the finger and an upper member overlying the finger with the knife blade having a length so as to project forwardly from a front tip of the upper and lower members.