Cutter blade sharpener and method

A cutter blade sharpener and method allows for quick, easy and uniform sharpening of tree felling head circular cutters. Each cutter blade is individually removed from the circular cutter and is positioned on the sharpener, one at a time whereby the cutter blades are then ground in uniform fashion. The sharpener includes a tubular frame having a slide table mounted thereon for both lateral and longitudinal movement of the cutter blade proximate the grinding wheel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AND OPERATION OF THE INVENTION For a better understanding of the invention and its method of operation, turning now to the drawings, FIG. 1 illustrates preferred cutter blade sharpener 10 having frame 11 preferably formed from tubular steel. Frame 11 includes front legs 12 , 12 ′ and rear legs 13 , 13 ′. Rigidly positioned on tubular frame 11 is shelf 14 to which slide table 15 is mounted. Slide table 15 is preferably a conventional compound or bi-directional milling table as sold by Enco Manufacturing of 135 South LaSalle, Chicago, Ill. 60674. Other manufacturers of such slide tables include Penn Tool Company, 1776 Springfield Avenue, Maplewood, N.J. 07040. Slide table 15 is mounted to shelf 14 as by bolts 16 (only one shown in FIG. 1 ) and includes table base 17 and table top 18 . Table base 17 is movable laterally on frame 11 by turning crank handle 19 whereas table top 18 is movable longitudinally on frame 11 by turning crank handle 20 as seen by the arrows in FIG. 2 . As would be understood, table base 17 and table top 18 move in relatively perpendicular directions for adjustment purposes for precision grinding. Rigidly affixed to table top 18 is upright L-shaped support arm 24 which contains slot 25 as seen enlarged in FIG. 3 . Slot 25 receives support arm handle 27 which includes threaded end 28 . By placing cutter blade 30 seen in FIGS. 4 and 5 in V-shaped guide 31 , handle 27 can then be used to tighten end 28 into threaded channel 34 of cutter blade 30 to releasably secure the same onto support arm 24 . Once so secured, handle 19 and handle 20 are turned in a clockwise direction to urge cutter blade 30 into engagement with grinding wheel 40 . Grinding wheel 40 is preferably a ten inch (25.4 cm) O.D., 4.5″ L.G. (11.43 cm) conventional cylindrical silicon carbide or aluminum oxide grinding wheel such as manufactured by Simonds, Inc., 248 Elm Street, South Bridge, Mass. 01550. On/off switch 42 ( FIG. 1 ) is used to activate, preferably standard three horsepower electric motor 43 having motor shaft 44 , which operates on 110v AC power. Adjustable stop 32 is positioned on frame 11 behind slide table 15 to terminate the rearward longitudinal motion of table top 18 . Stop 32 includes an upright post 29 shown in FIG. 2 which threadably receives stop rod 33 . Threaded stop rod 33 is used to abut table top 18 as shown in FIG. 2 to terminate its rear longitudinal movement by adjusting its length from upright post 29 . The preferred method of sharpening cutter blade 30 includes the steps of: firstly, removing preferably the most worn cutter blade from a tree felling head circular cutter (not shown) and threadably attaching it to handle 27 as shown in FIG. 3 . Threaded end 28 of support handle 27 is then placed within slot 25 of support arm 24 and is tightened thereon by rotating support handle 27 in a clockwise direction as cutter blade 30 is prevented from rotating by V-shaped guide 31 . Next, handles 19 and 20 of slide table 15 are rotated to bring a pair of cutter edges 35 of cutter blade 30 into contact with the edge of grinding wheel 40 as seen in FIG. 2 . Grinding wheel 40 is activated by throwing motor switch 42 and the sharpening begins. The amount or depth of grinding can be increased by rotating handles 19 and 20 in a clockwise direction to urge cutter blade 30 into grinding wheel 40 . Once blade 30 has been ground or sharpened properly by the movement of handle 20 , stop 32 is adjusted by rotating threaded rod 33 until contact is made with table top 18 as shown in FIG. 2 . Once the first pair of edges 35 of cutter blade 30 is so sharpened, switch 42 is thrown to deactivate grinding wheel 40 . Handles 19 and 20 can then be rotated in a counterclockwise direction and support arm handle 27 turned also in a counterclockwise direction in order to remove cutter blade 30 from support arm 24 . Cutter blade 30 is then rotated 90° on handle 27 and replaced in support arm 24 where it is again tightened by turning handle 27 and the grinding process begins again. Stop 32 remains in position so that each pair of cutting edges 35 of each blade 30 will be ground to the same depth. Thus, each cutter blade 30 as shown in FIGS. 4 and 5 are sharpened four times (once for each of the four pairs of cutting edges 35 ). When the sharpening of the first cutter blade selected is complete, the remaining cutter blades 30 which may be for example seventeen, are then likewise sharpened with grinding wheel 40 . Stop 32 prevents variation in the sharpening depth for each cutter blade 30 . Thereafter, the cutter blades are replaced on the circular cutter (not seen) and tree felling can recommence. The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.