US2379569A - Abrasive tool - Google Patents

Description

July 3, 1945.. ELUS 2,379,569

ABRASIVE TOOL l Filed Jan. 22, 1944 IN VEN TOR.

Patented July 3, 1945 ABRASIVE 'rooL Robert Ellis,York, Pa. Applicaties-January 22,1944, serial No. 519,269 s claims. (cl. 51-905) This invention relates to abrasive tools and the object of the invention is the provision of an abrasive tool in any of the many commercial forms 'such as hones, knife sharpeners, etc., which willhave magnetic properties.

A further object of the invention is the provision of an abrasive instrument or tool in which the core maybe of magnetic material and per- 'manently magnetiz'ed and the outer shell of the tool'of any desired abrasive constituency.

Other and further objects will appear in the specifications and be specifically pointed out in the appended claims, reference being had to the accompanying drawing exemplifying the invention and in which Fig. 1 is an isometric view invention in the shape of a hone.

Fig. 2 illustrates another form of my abrasive tool in the shape of a knife Sharpener, shown in.

longitudinal section.

Fig. 3 is a cross-section on the line 3-3 of Fig. 2.

lFig. 4 illustrates a microscopic view of the edge of a knife and how my magnetic abrasive toolv will produce a sharper edge than an ordinary abrasive'tool.

Referring to the drawing in which like numerals and characters of reference refer to similar parts throughout the several views, the numeral 5 denotes an ordinary abrasive honein shape. 'I'he ingredients of the abrasive hone may also contain any of the numerous and varied mixtures of abrasive and binder therefor. However, in my abrasive hone I also include to any of the many compositions above referred to, a quantity of magnetic material such as powdered steel, powdered alnico" or anyof the fewadditional magnetic elements or alloys now generally employed in the manufacture of permanent magnets. The relative quantity of this powdered or granulated magnetic ingredient, added to the abrasive and binder of the hone may be approximately ten to ninety per cent, depending to what particular use .the hone or abrasive tool is to be put to. The hone may also constitute a bar of steel set with-abrasive diamonds or diamond dust, the steel bar being then magnetized. as in Fig. 1. Y

In the drawing, the abrasive particles such as carborundum, emery, etc., may be indicated by the numeral y and the magnetic particles by 1 although in use, the relative size of both ingredients would be a matter conditioned by the particular requirements. In makingthis abrasive hone or tool, the ingredients'as mentioned above are first compounded in the proper proportion with a binder, poured or compressed Vin a mold and vwhen in solid or semi-plastic condition'are permanently magnetized by momentarily being thrust within a strong magnetic field produced by direct of one form of my electric current. The abrasive tool thereby becomes residually magnetized and is to all intents and purposes a permanent magnet, the letter N denoting the north magnetic pole and the letter S the south pole. i

In use, attention is drawn to Fig. 4 which simulates a microscopic view of the edge of a knife. In, there being always ribbons" 8 projecting at angles from the center line of the knife blade. Anordinary abrasive hone. can never prevent these microscopic ribbons and shreds from forming as they are too thin to be abraded,- simply bending over when the hone presses thereon. With my magnetic hone however, these thin ribbons are attracted to the hone and the magnetic attraction between the hone and the ribbons provide the proper friction, regardless of 'how 4thin or flexible the ribbons are, for abrasive action and these ribbons are thus abraded away or sharpened, leaving a sharper and clearer edge to the knife than was heretofore possible, the resultant edge being denoted by the numeral 9. Furthermore, in any honing or abrading operation, it has heretofore always been necessary to apply pressure against the surface of the article being abraded as well as longitudinal motion. With the use oi my magnetic abrasive tool, the mutual magnetic attraction between the tool and the ferrous article eliminates the necessity of this pressure and only longitudinal motion is required, thus making the act of sharpening `much easier. An additional advantage is that heretofore the line particles of steel which were abraded from the knife were either scattered around as dust or clung to the knife, later to contaminate food which was cut with the knife. During the sharpening pro cess with my magnetic hone, such abraded steel particles will forcibly cling to the hone by magnetic attraction where they can later be wiped off with a cloth. A still further advantage of my magnetic abrasive tool is the fact that a sharper edge can be given to the knife I0 by passing the hone 5 thereover, in thev direction of arrow Il, by holding the hone at only a very slight angle, as illustrated, from the face of the blade, the usual practice having heretofore been to hold the hone at a greater angle which resulted in a more stubthe abrasive material I molded around this core. The abrasive shell should be thin enough to permit the magnetism inherent in core l2 to be effective on the article to be sharpened. The numeral il represents a handle which is fastened to the magnetic steel core i2 by means of screw il. A number of annular grooves I5 are provided in the magnetic core I2 so that the abrasive shell may better adhere thereto.

From the foregoing description it will be apparent that I have evolved an abrasive tool with novel properties so that a knife or other edge may be given a sharper edge, one which will require less physical eil'ort to operate and one which will prevent the usual abraded steel dust from flying about. Various changes may be made in the embodiment of the invention hereinabove specilically described without departing from or sacriiicing the advantages of the invention as defined in the appended claims.

I claim:

1. The process of making an abrasive tool which consists of the following steps; ilrst mixing magnetizable material with powdered or granulated abrasive material and a binder; second, molding or pressing said mixed material into a solid mass;

and third, inserting the solidified article into a magnetic field generated by direct electric current so that it will retain its magnetism perma nently.

2. The processor making an abrasive tool which consists or the following steps; rst, mixing powdered or granulated magnetizable material with powdered or granulated abrasive material and a binder; second, pouring or pressing said mixed material into a mold; third, inserting the plastic or semi-plastic material within said maid into a magnetic ileld generated by direct electric current so that the said magnetizable particles in said mold will arrange themselves in magnetically favorable positions in alinement with the magnetic lines of force of said magnetizing field and becoming permanentlymagnetized; and fourth, permitting said plastic or semi-plastic material in said mold to harden.

3. An abrasive tool comprising a mixture of .magnetizable particles and' abrasives in powdered or granulated form, and a binder for said particles, said tool form an individual magnet with oppositely disposed magnetic poles. l

. ROBERT ELLIS.

being permanently magnetized to

Images