Cutter blade sharpener and method

Abstract

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.

Description

FIELD OF THE INVENTION

[0001] The invention herein pertains to blade sharpeners and particularly for sharpeners for cutter blades as are used with tree felling heads.

DESCRIPTION OF THE PRIOR ART AND OBJECTIVES OF THE INVENTION

[0002] Many standard tree felling heads utilize circular cutters which turn at high rates of speed for felling trees. Such circular cutters commonly have eighteen cutter blades, each with four cutting edges located along the periphery of the circular cutter. The cutter blades regularly wear, sometimes in an uneven fashion and must be removed and discarded. The standard practice is to remove the blades from the circular cutter and replace them with new cutter blades.

[0003] With recent increased costs of labor and equipment in the tree harvesting industry, maintenance of circular cutters having a plurality of cutter blades are a source of concern. It is not prudent to use a circular cutter until it is completely worn and then discard it. Also, it is now not prudent or economical to hand grind each cutter blade to attempt to restore it to its original sharpness. As a result there has become a need for a powered cutter blade sharpener which is fast and which can be efficiently operated for uniform sharpening among the individual cutter blades to keep the circular cutter in balance.

[0004] Thus, with the aforesaid problems and disadvantages of discarding and replacing cutter blades, the present invention was conceived and one of its objectives is to provide a cutter blade sharpener which can be readily operated to provide uniform sharpening of cutter blades several times before discarding.

[0005] It is a further objective of the present invention to provide a method of sharpening cutter blades which allows cutter blades to be reused again and again.

[0006] It is still another objective of the present invention to provide a cutter blade sharpener which will allow all the blades of the circular cutter to be sharpened to the same degree and depth.

[0007] It is still a further objective of the present invention to provide a cutter blade sharpener and method which includes a grinding wheel which is powered by an electric motor.

[0008] It is yet a further objective of the present invention to provide a cutter blade sharpener which utilizes a conventional slide table for bi-directional movement of the cutter blade during sharpening.

[0009] It is another objective of the present invention to provide a cutter blade sharpener which includes a stop to limit the movement of the slide table to ensure uniform sharpening from blade to blade.

[0010] Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.

SUMMARY OF THE INVENTION

[0011] The aforesaid and other objectives are realized by providing a cutter blade sharpener having for example, a tubular frame with a 110V, 3-5 horsepower electric motor mounted thereto. The electric motor drives a standard cylindrical silicon carbide or aluminum oxide grinding wheel which is rigidly affixed to the motor shaft. A standard slide table is mounted to the frame proximate the grinding wheel for adjustably positioning the cutter blade against the grinding wheel. The slide table includes a base which is laterally movable and a table top which is longitudinally movable, relative to the frame. A support arm which defines a slot for receiving a threaded handle is affixed to the table top.

[0012] The first cutter blade selected for sharpening, being the most worn, is attached to a threaded handle. By placing the threaded handle in the slot and tightening the same, the cutter blade is prevented from movement during sharpening. A V-shaped guide is positioned below the slot on the support arm to prevent the cutter blade from rotating as it is tightened onto the handle and during grinding. An adjustable stop attached to the frame terminates the rear longitudinal movement of the table top. By thus adjusting the stop, an exact rear position is provided whereby each of the four pairs of edges of the cutter blades are sharpened to the same degree or depth. Once the first edge is sharpened, the cutter blade is moved away from the grinding wheel and the cutter blade is loosened on the handle to allow the blade to rotate 90°. The rotated cutter blade is retightened and the second edge of the cutter blade is then sharpened by rotating the table base handle and table top handle to bring the cutter blade into contact with the grinding wheel. After all four edges of the cutter blade have been sharpened thusly, the first cutter blade is removed and replaced on the circular cutter while another cutter blade is attached to the arm support as aforedescribed and the sharpening method starts anew. The stop, having been adjusted for the most worn blade, remains in position so that all cutter blades are sharpened to the same depth. Uniformly sharpened cutter blades maintain balance for the circular cutter as it spins during cutting. A relatively large number of blades can be sharpened quickly and efficiently by relatively unskilled personnel by using the method and sharpener thus described.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 demonstrates a perspective view of the cutter blade sharpener of the invention;

[0014] FIG. 2 depicts a top view of the cutter blade sharpener as shown in FIG. 1;

[0015] FIG. 3 pictures an enlarged view of the slide table as removed from the frame with the handle and cutter blade exploded therefrom;

[0016] FIG. 4 shows a perspective view of a conventional cutter blade; and

[0017] FIG. 5 shows a side view of the cutter blade as seen in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AND OPERATION OF THE INVENTION

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.

Claims

1. A cutter blade sharpener comprising: a frame, a grinding wheel, said grinding wheel mounted on said frame, a slide table, said slide table positioned on said frame, a cutter blade support arm, said support arm attached to said slide table whereby a cutter blade can be affixed to said support arm for sharpening by said grinding wheel.

2. The cutter blade sharpener of claim 1 wherein said slide table comprises a table top, a table base, said table top movably positionable above said table base.

3. The cutter blade sharpener of claim 2 wherein said table top comprises a top crank, a top threaded member, said top crank attached to said top threaded member for rotating the same, said table top threadably connected to said top threaded member whereby rotation of said top crank will move said table top along said slide table.

4. The cutter blade sharpener of claim 2 wherein said table base comprises: a base crank, a base threaded member, said base crank attached to said base threaded member, said table base threadably joined to said base threaded member whereby rotating said base crank will move said table base along said slide table.

5. The cutter blade sharpener of claim 1 wherein said table top is movable perpendicularly to said table base.

6. The cutter blade sharpener of claim 1 further comprising a table base stop, said stop attached to said frame for limiting the movement of said table base.

7. The cutter blade sharpener of claim 1 further comprising a support arm handle, said support arm handle attached to said support arm for affixing a cutter blade thereto.

8. The cutter blade sharpener of claim 7 wherein said support handle comprises a threaded shaft, said support arm defining a shaft slot, said threaded shaft mountable within said shaft slot.

9. The cutter blade sharpener of claim 1 further comprising an electric motor, said electric motor attached to said grinding wheel for driving the same.

10. The cutter blade sharpener of claim 1 wherein said frame further comprises a plurality of legs.

11. A method of sharpening a cutter blade utilizing a grinding wheel mounted on a frame with a slide table having an adjustable, movable table top, a support arm affixed to said table top and an adjustable, movable table base, and an adjustable stop attached to the frame comprising the steps of:

a) attaching the cutter blade to the support arm;

b) adjusting the support arm so the cutter blade contacts the grinding wheels; and

c) activating the grinding wheel to sharpen the cutter blade.

12. The method of claim 11 further comprising the step of adjusting the stop.

13. The method of claim 11 further comprising the step of adjusting the table base.

14. The method of claim 11 further comprising the step of rotating the cutter blade while on the support arm.

15. The method of claim 11 further comprising the step of removing the cutter blade from the support arm.

16. The method of claim 14 wherein rotating the cutter blade comprises the step of rotating the cutter blade four times.