DISC AND KNIFE CUTTER ASSEMBLY FOR MOWING

A cutting assembly for a mowing machine has a disk ( 12 ) and a knife member assembly. The disk ( 12 ) has a surface portion ( 14 ) of which at least a peripheral portion is planar. At least three knife members ( 18 ), which have a cutting edge ( 50 ), a beveled surface portion ( 48 ) which extends from the cutting edge ( 50 ) and a body surface portion ( 60 ) which extends from the beveled surface ( 48 ), are mounted to the disk ( 12 ) at positions so that the knife members ( 18 ) are displaced substantially equidistantly one from another and so that upon rotation of the disk ( 12 ) in a plane about a central disk axis, the cutting edge ( 50 ) of the knife members ( 18 ) extends away from the disk ( 12 ), and the body surface ( 60 ) is. with respect to the disk planar surface, inclined at an angle.

DETAILED DESCRIPTION OF THE INVENTION An assembly according to the present invention is illustrated in an exploded perspective in FIG. 1 and is designated generally and collectively by reference numeral 10 . Although the illustration of FIG. 1 only shows disk 12 as having planar surface 14 which extends from peripheral disk edge 16 , as is preferred in accordance with the present invention, the opposing surface of disk 12 also may be understood to be entirely planar. As indicated by the exploded view, knife members 18 are to be mounted adjacent lower planar surface 14 . Mounting means include bolt 20 and nut 22 and bushing 24 which are sized and configured, together with disk apertures 26 (4 in number) and knife aperture 28 , so that knife 18 is pivotally movable so that upon rotation of the disk, the knife is thrust and maintained in a cutting position by centrifugal force. As will be noted, disk apertures 26 are spaced at distances so that adjacent knife members are positioned substantially equidistantly apart one from the other. Disk 12 is provided further with centrally disposed aperture 36 which is sized to accommodate bolt 38 which, in turn, is sized to engage fixedly threads of spindle 40 which is integral with a mowing machine and its drive means, indicated and represented by a labeled box, for driving disk 12 . A washer 41 may be employed between the head of bolt 38 and disk surface 14 . As will be appreciated, the spindle and bolt 38 should be threaded, as should bolts 20 , relative to direction of rotation so that the bolts remain tight during rotation. Knife member(s) 18 is illustrated in each of FIGS. 1 and 2 as comprising handle portion 42 which has a planar surface portion in the area surrounding aperture 28 . Knife member handle portion 42 extends from aperture 28 to a somewhat curved portion 44 , which defines an area of transition (dashed line) between handle portion 42 and blade portion 46 , the distinction between blade portion 46 and handle portion 42 being seen more readily at the juncture ( 44 ) of handle portion 42 and blade portion beveled surface 48 , which trails from cutting edge 50 . As will be noted, a second blade edge 52 opposes cutting edge 50 , and knife end 54 extends transversely between the opposing edges. The blade body surface which is inclined is designated in FIG. 2 by reference numeral 60 , and the inclination may be seen by the view of knife end 54 in drawing FIG. 3 , that Figure, in sum thereby also presenting a cross-sectional view of blade portion 46 of FIG. 1 . As is preferred, and as illustrated in FIG. 3 , the blade is provided with two beveled surfaces 48 , as in FIG. 1 , and 62 and two cutting edges 50 , as in FIG. 2 , and 64 , and the blade portion also is configured so that upon wearing down cutting edge 50 upon its use as a leading edge for cutting and turning the knife over for use as a leading cutting edge, surface 66 is likewise inclined in accordance with the present invention. Thus, additionally, both opposing surfaces of knife handle 42 which surround aperture 28 ( FIG. 2 ) should, in this embodiment, be planar for surface-to-surface-contact with a planar disk surface in an intimate manner. As may be gathered from the foregoing drawing description and in view of the present conventional construction of mowing machines, particularly those employed for home-owner use and for commercial lawn-care maintenance, replacement of cutter means heretofore employed with an assembly according to the present invention and/or reconfiguring a prior cutter means to be in accord with the present invention, so that a mower drives an assembly as defined herein, is a relatively simple matter. As also is clear from the foregoing, various modifications of the present invention may be made without departure from the spirit and scope of the disclosure, and the invention may be embodied suitably in the absence of elements or members not specifically disclosed herein.