US267751A - De lancy kennedy - Google Patents

Description

(No Model.)

' DE LANGY KENNEDY.

METAL PUNGH. No 267,751. Patented Nov. 21, 1882-;

WITNESSES 1.7V VEJV TOR .[lttorneysp UNITED STATES PAT NT FFICE.

DE LANOY KENNEDY, OF NEIV YORK, N. Y.

METAL-PUNCH.

SPECIFICATION forming part of Letters Patent No. 267,751, dated November 21, 1882. Application filed May 11, 1882. (No model.) Patented in Canada February 17, 1880, No. 10,928.

To all whom it may concern Be it known that I, DE LANGY KENNEDY, of the city, county, and State of New York, have invented certain new and useful Improvements in Metal-Punches; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, and to the letters of reference marked theron.

My present invention is an improvement upon that described in Letters Patent of the United States No. 161,Q68, granted to me April 13,1875, and'forms a part of the subject of Letters Patent of Canada No. 10,928, granted February 17, 1880. The characteristics of the punch constituting the invention patented in line. As a result of the use of my said patented invention there are comparatively no defieotion of the metal punched, no elongation of the hole, and no appreciable difference visible between the shape of the hole punched and the periphery of the punch, whether-the latter .be round, square, or oval.

The first part of myinvention relates to forming the punch with a first cutting-point at the periphery and a central bearing, and removing a part of the surface area or cutting-face of the tool between said point, so that the resistance met with during the cutting-stroke may, be reduced at the side of the punch first called into requisition and the strain on the tool the better equalized.

The second part of my invention relates to providing the punch with two first cuttingpoints at opposite sides of the periphery, and uniting said points by spirals, each of which extends one-half around the circumference of the punch. In the punch, as constructed in accordance with this part of my invention, a

. portion of the surface or cutting-face'area. of

the tool is removed between each first cuttingpoint and the central hearing or narrow base.

' In the drawings, Figure l isa side view of a punch embodying my invention from one point of observation. Fig. 2 is a similar view from a second point ofobservation. Fig. 3 is a similar view from a third point of observation. Fig. 4. is a similar view from a fourth point of observation. Fig. 5 is a plan of the punch. Fig. 6 is a plan view of the punch constructed with two first cutting-points at the periphery, connected by spirals, as above mentioned. Figs. 7 and 8 are hereinafter referred to.

Similar letters of reference indicate similar parts in the respective figures.

A is the punch, having a central bearing or narrow base, a, which, with the center point, 1), forms the mechanical center of the tool. A guiding or easing edge is shown by c, uniting the first cutting'point d of the periphery with i the spiral. The edge 0 serves to guide, ease, and clear the tool during the cutting process, and at the same time greatly strengthens the tool, which without said edge would be weak at the vertical line, which would unite the first cuttingpointdof the periphery with the spiral. A portion, 6, of the area or cutting-face of the punch is removed, the resistance to the side of the punch from which the portion is taken being thereby lessened, the first cutting-point d of the periphery and the center bearing, a, doing the cutting work, being nnretarded by the presence of an'intermediate body of metal, which would be inoperative for useful work.

In Fig.6 the punch is shown with the double spiral before mentioned. It will be seen that the punch has two cutting-points at the pe- First. Less power is requiredto operate the I00 tool than that ordinarily demanded, a firm bearing being obtained at the center, and the force being expended progressively as the cut-- ting or shearing is done, and not at one time, as with the common flat-faced punch.

Second. It is found that the tensile strength of the metal punched is less impaired when punched by the use of my invention than by the ordinary means.

Third. It is found that the hole can be punched in the precise location desired without deflection in the plate.

Fourth. The hole punched is perfectly round or of the shape of the punch, no elongation or distortion being seen, this desirable result accruing from the joint operation of the peripheral and central cutting parts, the first cuttingpoint of the periphery operating simultaneously with the center bearing, and the force applied after the engagement of these parts with the metal to be punched being in a true perpendicular direction. 7

I make no claim at this time for the cuttingedge of the punch extending from the central point or bearing to the periphery, as that was claimed and allowed in my United States Patent of April 13, 1875.

I disclaim the constructions shown in plan view in Figs. 7 and 8. In both views no part of the area or cutting-face of the punch is removed, as at c in the other figures. In Fig. 7 the construction is that of a single spiral vrith a central bearing or narrow base, and with no part of the area or cutting-face of the punch removed. In Fig.8 the construction is that of a double spiral, having also a central hearing or narrow base, with no part of the area or cutting-face of the punch removed. The constructions shown in Figs. 7 and 8 have been in extensive use and on sale by me in this country for about five years, it having in practice been found advantageous to modify the formation of the punch patented to me in the United States, as aforesaid, in accordance therewith. I therefore disclaim as a part of my present invention a punch having a center and a narrow flat area or initial cuttingface extending across the tool, such, in view of the said public use and sale by me, not being now, as I am advised, subject-matter for avalid patent. I also disclaim as a part of my present invention the construction covered by Letters Patent of the United States No. 189,043, granted to me April 3, 1877, for improvement in projectiles, in which is found a cutting-edge extending radially. from the axis to the periphery and thence spirally around or partly around the periphery to-a point perpendicular to that touched by theline radiating from the axis; but

I claim as my present in vention-- 1. In the spiral shearing-punch A, the cutting-face, having a part, 6, removed between the center and first cutting-point of the periphery, substantially as and for the purpose set forth.

2. In the spiral shearing-punch A, two first I cutting-points at opposite sides of the periphery, united by spirals, the cutting-face, having parts 0, removed between the center and first cutting-points, substantiallyas and for the purpose set forth.

3. In the spiral shearingpunch A, a central bearing or narrowbase, a, and a center point.

my hand and seal this 11th day of May, 1882.

DE LANOY KENNEDY. Witnesses:

W. '1. Cons, A. DE FIGANIERE.

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