US2465678A - Machine for sharpening knife blades - Google Patents

Description

March 29, 1949. D. B. ELLIG 2,465,678

MACHINE FOR SHARPENING KNIFE BLADES Filed March 19, 1947 Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to knife sharpening machines and while it may be used for sharpening a great variety of knives, it was primarily developed for sharpening ensilage knives. Accordingly, since an ensilage knife sharpening machine is intended for use only during two to four Weeks a year, or during the harvesting season and stored away the rest of the year, it must be made at low costs, because it must be idle most of the time. nated as well as threaded shafts. The machine is completely under the control of the operator at all times as to speed, starting and stopping. No brakes are used and the entire machine is made of steel so that breakage and repair costs are practically nil.

A motor is employed on the machine to drive the grinding wheel arbor, which motor may of course be employed for other purposes, when the grinding machine is idle.

For adjusting the knife holder to different widths, and bevels, a guide rod or rail, held in desired height in a slit of about 45 inclination on the plate is employed. By this means it is possible to move the knife easily toward and away from the rotating grinding wheel. The operation movements are all controlled by the operator thru a hand lever placed at one end of the machine.

These and other objects and advantages will be readily understood from the subjoined description, aided by the attached drawing.

Like numerals denote the same details in the difierent views of the invention.

Figure 1 is a view in front elevation of the machine with a part thereof broken away;

Figure 2 is a top plan view of the same;

Figure 3 an end view of the machine seen from the right end thereof;

Figure 4 a detail top plan View on an enlarged scale of the knife holder and a part of the actuating mechanism;

Figure 5 is a front view of the knife holder as seen in Figure 4 and Figure 6 shows a side elevation in detail of an adjusting screw and nut for setting the knife to the desired bevel angle.

Numeral l denotes in general a stand or table needed for carrying all machinery and is provided with a cooling tank I! thereunder and a motor l2, on a braced support i l at the rear thereof. The grinding or emery wheel l3 with its arbor, is mounted in ball bearings on a bracket l of metal in about the middle of the table, preferably welded thereon.

Accordingly, all gear trains are elimi-* The arbor it carries at one end a pulley ll, which runs by a V-belt Ila from the motor I2.

Between two upright bearing plates l8, one erected at each end of the table I0, is adjustably secured by nuts a guide rod I9 in arcuate slots I 9a. A knife holder 20 with sleeves 2| engages the rod IQ for sliding back and forth thereon. The knife holder 25] is provided with holes and slots for securing thereon various knives for grinding in the usual manner. A knife after being secured on the holder 20 is pressed against the emery wheel by means of a spring 23 which fits over a stud or post 24 and is held compressed by means of a slotted bar 25 which is pivoted on the table. On the stud or post 24 is also hinged a connecting rod 26 the outer end of which is pivoted to a handlever 21, hinged at 28 near the corner of the table.

The bearing plate I8 for the guide rod I9 is slotted at an angle, about 45, so as to move the knife toward, or away from the emery wheel l3, or in other words, the rod [8 and slots I9a provide the means for adjusting the knife holder 20 for different widths and different bevels of the knife to be ground, whether it is of the ensilage type or the lawn mower, or any similar type.

The guide rod I9 is secured in a fixed position by means of a collar on a bolt 30 engaging the guide rod IS, the pressure being always downward and away from the emery wheel IS. The bolt 30 passes thru a plate 3|, and has an adjusting nut 32 threaded thereonto bear against the plate 3|.

After the knife holder 20 has been set for cutting a desired bevel on the knife blade, by means of the adjusting nuts 32 and bolts 30 on the guide rod l9, at each end of the machine, there is nothing further to adjust, as the spring 23 holds the knife against the emery wheel I 3 with an even pressure along the full length of the blade.

The operator has full control of the machine and the grinding action and is able to run the knife across fast or slow, or stop at one point to grind down a high spot, caused by welding, for instance, by simply holding the operating handle still a needed length of time.

The following advantages and important features of my invention should be noted:

The machine saves from V; to A; of the time, usually needed for sharpening any kind of bevel edged knives up to 24 inch length and which cannot be burned on account of continuous application of cooling medium. No special training is required to operate the machine which easily set up and require only one adjustment for each set if knives.

The machine is equipped with a pump for supplying cooling medium from the tank II to the emery wheel I3, so that heavy feed, when needed may be used.

It is to be understood that the invention as herein disclosed may be varied from the details described and shown without departure from the spirit of the subjoined claims.

I claim:

1. A machine for sharpening knife blades having a straight cutting edge, comprising a working table, a grinding wheel on top thereof, means for rotating the wheel, a knife blade holder, a guide rod having said holder mounted thereon for reciprocatory movement, a bracket at each end of the table having slanting slots in which the ends of said rod are held and permitting height and angularity adjustment of the holder carried thereby in regard to said grinding wheel, and means for reciprocating the blade holder along said guide rod.

2. A sharpening machine for knife blades, as described in claim 1, wherein said means for reciprocating the blade holder consists of a hand lever hinged on said table near one end of said guide rod, a stud on said holder, a slotted swinging bar hinged on said table and having said stud engage in the slot thereof, and a spring acting between said holder and said bar urging the holder toward said grinding wheel, and link connection between said stud and said handlever.

3. A sharpening machine for knife blades as described in claim 1, wherein an arbor is provided for said grinding wheel, the axis of which is parallel to said guide rod, a pulley on said arbor, an electric motor having belt connection 4 with said pulley; a shelf carrying said motor on one side of the table, a brace for said shelf, said operating means consisting of a hand lever hinged on said table near one end of said guide rail, a stud on said holder, a slotted swinging bar hinged on said table and having the stud engaged in the slot thereof, a spring acting between said holder and said bar urging the holder toward said grinding wheel, and link connection between said stud and said handlever.

4. A sharpening machine for knife blades as described in claim 1, wherein an arbor is provided for said grinding wheel, the axis of which is parallel to said guide rod, a pulley on said arbor, an electric motor having belt connection with 'said pulley, a shelf carrying said motor on one side of the table and a brace for said shelf, said operating means consisting of a hand lever hinged on said table near one end of said guide rail, a stud on said holder, a slotted swinging bar hinged on said table and having the stud engaged in the slot thereof, a spring acting between said holder and said bar urging the holder toward said grinding wheel, link connection between said stud and said handlever, and a cooling tank provided beneath the table.

DONALD B. ELLIG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS McMillen Mar. 12, 1940

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