US1573875A - Knife sharpener - Google Patents

Description

Feb. 23 1926. 1,573,875

J. E. SHAW KNIFE SHARPENBR Filed August 21, 1924 l mun INVENTOR BY w fl ATTORNEYS Patented Feb. 23, 1926.

UNITED stares JAMES E. SHAW, OF GERMAN TOWN, PENNSYLVANIA.

KNIFE SHAR PENER.

Application filed August 21, 1924. Serial No. rsaase.

To all whom it may concern:

Be llfliIlOWIl that I, JAMES E. SHAW, a citizen of the Un ted States, residing at .5150 lVakefield Street, Gerinantown, county of Philadelphia, and State of Pennsylvania, have invented a certain new and useful Improvement in Knife Sharpeners, of which the following is the specification.

My InventiOnrelates to the art of tools or devices adapted for the sharpen ng ot ,lrnives, scissors, or other blades, and it has for its object to produce a device through which the blade is designed to be drawn in order to produce the sharpening effect.

Another object is to produce a device of this character which will. only cut :away or turn (in the sharpening operation) one side surface of the blade, the other surface not being affectedin any manner by the drawing of the knife through the device.

Another object is to produce a device of this character in which the blade wi l be sharpened with a' convex rather than a con cave edge, as is produced by 1117St sharpeners.

A further object is to construct the device in such a manner that the drawing of the blade through one side of the device will sharpen, ina convex manner, one side of the blade, and the drawing of the blade through the otherside of the sharpener will sharpen the reverse side of the blade, the two s des obviously mating to form a keen, sharp edge when the blade has been properly sharpened.

of a knife, illustrating the manner in which the blade is sharpened.

Fig. 3 is a detail View of the guide me1nher I employ. I Fig. 4 is a detail View of side elevation of one of the cutting plates.

Fig. 5 is a transverse sectional view of my device,the section being taken through the guide member and one of the cutting plates so as to illustrate the manner in which they are joined to the body member.

Fig. 6 shows a detail view of the mating position of one of the cutting plates with the guide member to form notch into which the blade is inserted for sharpening purposes.

Referring to the accompanying drawings the referencenumeral 10 is used to indicate a base support, or'the like, to receive the functioning elements constituting my device. This base may be of any desired material, and may have a handle such as shown at 11 so that the device may be used as a tool and simply held in the hand and the blade drawn through the operating parts, or this base may be bolted to a table, or the like, in any desired manner (no such manner being illustrated) if preferred. On this base l have mounted in stationary position a guide member 12 having its sides 13 and 1-]: on an inclined plane, or they may be vertical, as shown in dotted lines, and mating with these inclined planes are the concave edges of the cutting, or sharpening, plates 15 and it; which I employ. These plates are arranged to face each other in the manner shown, their base portions przictically contacting and the concaved lacing edges, providing a considerable space to extend between them at their upper edges. The guide member 12 lies flush against the plates l5 and it}, and bolts secure the guide member and S'lllt; ening plates in their respective and relative positions, fixed with relation to each other. The guide plate extends upwardly with the cutting plates and lies flush against one side of the said plates, the upper end of the guide member being smaller than the lower end, as hereinbefore stated, this construction forming the two notches l7 and 18 one between the cutting edge of the plate 15 and the inclined or vertical edge 13 of the guide member 12, and the other notch being formed between the cutting edge of the cutting plate 16 and the inclined or vertical edge ll; of the guide member 12. These two notches are designed to be, and by construction are, of substantially the same size and formation.

From this construction it is obvious that the cutting edge of the cutting plate being concave from the base to the top of the cutting plate and the vertical or inclined edge of the guide member being 011 a straight but vertical or inclined plane. the crossing of the concave surface of the cutter with the straight surface of the guide member will cause the notch to be concave on the cutter side and straight on the guide side. It is also obvious that the concave side of the notches will be reversed as to each other.

'ing a keen, sharp edge on In practical operation it being desired to sharpen a blade it is. inserted in the notch 17 until the edge of the blade rests at the angle formed by the concave edge of the cutting plate and the straight edge oi? the guide member. By pulling the blade through the not-ch amli eari11g slightlydown upon the same the cuttingplate cuts away more satisfactory and etlicient than the edge produced by the usual types of Sharpeners.

By my construction scissor blades, which are only sharpened on one surface thereof may be easily and quickly sharpened, one blade being drawn through one ofthe notches in the device and the other blade being drawn through the other notch. It has also been demonstrated that blades being sharp-- ened with this convex edge give not only a more substantial cutting edge, but a much better service, this being proven by demonstration in the actual use of the sharpeners.

In the drawings I have illustrated simply a preferred form of construction for my device, but I Wish it understood that I do not desire to be limited to the construction shown or described in the specification. nor to limit the scope of the protection of my invention except as set forth in the accompanying claims.

Having described my invention what I describe to secure'by United States Letters Patent is:

1. A sharpenercomprising a guide member with inclined'edged surface and a cutting plate provided with a concave surface extending downwardly from its upper extremity, said concave edge crossing the vertical or inclined surface of the guide member, so as to form a notch concaved on the cutting side and straight on the guide side.

A sharpener comprising a pair of cutting platcs spacedfrom each other at their upper extremities and each provided with concave surfaces extending downwardly and on the inner side from their upper extremities, and a guide plate adjacent one side of the said plates and extending upwardly between them, said plate having inclined edges to cross the respective concave edges of the cutting plates so as to form on each. side of the guide member a notch concaved on its outer surface and straighten its inner surface.

3. A sharpener for blades comprising a notch formed with one straight side, its other side being formed with a concave cutting plate. i

4. A sharpener comprising a cutting plate whose opposite edges are concave, being narrow at the topof the concave edges and broad at the bottom of the concave edges.

AMES E. SHAW.

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