now referring in detail to the drawings it may be seen from fig1 and 2 a disc blade or simply a disc indicated by general reference number 1 , such as a coulter disc , either an entirely flat or planar disc or a well known concave / convex disc . disc 1 is provided with a plurality of waves 2 that according to the invention have a particular pattern to which reference will be made below . disc 1 is preferably made of metal , such as iron , steel and other metals and alloys and has a general circular configuration with a peripheral circular cutting edge 3 , preferably a sharp edge , and a central portion 4 . preferably , the waves have an inwardly radially decreasing depth in order to merge into central portion 4 that includes means , such as one or more orifices , for rotatably mounting the disc in a farming machine or implement not shown , preferably a no - till implement . thus , waves 2 extend radially inwardly from the cutting edge 3 towards the central portion . distinctly from the conventional waves or flutes the inventive wavy design has a particular configuration in order to form a sawtooth pattern . more particularly , each wave 2 is defined , as better illustrated in fig3 , by an upwardly extending shorter segment 5 and a downwardly extending larger segment 6 in a manner that both segments define an asymmetric crest “ c ”. while reference is made to upwardly 5 and downwardly 6 segments , these physical references are taken according to the view of the disc as illustrated in the cross - section of fig3 , however segments 5 , 6 may extend inversely , that is downwardly and upwardly respectively . while there is no restriction about the length relationship between segments 5 , 6 , other than the design restrictions of the disc , preferably , segment 6 is from about 3 to 10 times the length of segment 5 and preferably about 5 to 7 times the length of segment 5 . in like manner , the depth hpp of the waves will depend on the desired design parameters , kind of soil , type of agricultural machine , etc . segments 5 and 6 , shown in fig3 , are the cross - sections of corresponding wave slim side 7 and wave wide side 8 , respectively . waves sides 7 , 8 are preferably flat or planar with a general triangle configuration . an angle α , as shown in fig3 , from about 80 ° to about 140 °, preferably from about 90 ° to about 130 °, and most preferably of about 125 °, is defined between both planar sides 7 , 8 . the above mentioned asymmetry of the crest resulting from the wide and slim adjacent sides or faces of the wave , provides the wave arrangement with a general saw pattern that have shown an effective performance in the cutting of the soil and stubble . the asymmetric design , providing the sawtooth pattern shown in fig3 , have shown a better penetration of the disc into the soil and through the stubble and any crop remainders , as well as it requires less mechanical forces with less stresses to enter the soil and less specific pressure onto the soil . in addition , distinctly from the conventional sinusoidal wavy coulters , the inventive sawtooth design provides less removal of the soil when exiting the soil at the rear part of the disc relative to the moving direction of the machine . the conventional waves cause the disc to remove and expel back or drive out pieces of soil when the rear part of the cutting edge is moving out of the soil . this is prevented by the inventive design and therefore the soil is permitted to keep a higher humidity degree what is better for culturing . another feature found in connection to the sawtooth design is that the cutting effect is more aggressive and the self sharpening of the edge is better . as illustrated in fig1 , 2 , each asymmetric crest c may extend radially along a corresponding axis forming an acute angle with radius , not shown , of the disc . alternatively , crest c may extend , in a disc or coulter generally indicated by reference 9 , along a radially extending curved axis as shown in fig4 , forming curved waves 10 . according to another embodiment , depicted in fig5 , crest c of waves 12 may extend radially coincident with the radius of the disc or coulter 11 . while preferred embodiments of the present invention have been illustrated and described , it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined in the appended claims .
a wavy farming disc for working the soil in farming activities , particularly in no - till works for seeding , wherein the disc comprises a plate having a peripheral circular cutting edge and a central portion , and a plurality waves in the plate with the waves extending radially inwardly from the cutting edge and defining a sawtooth pattern .