US795550A - Mower-knife. - Google Patents

Description

No. 795,550. PATENTED JULY 25, 1905.

. F. SCHUM.

MOWER KNIFE.

APPLIOATION FILED PEB. 2.1903.

@ www# UNITED sTATEs PATENT oEEIoE.

FRANK SCHUM, OF CHICAGO, ILLINOIS.

IVIOWER-KNIFE.

To all whom, it may concern.'

Be it known that I, FRANK SCHUM, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Mower-Knives; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improved knife for mowers and the like, the object being to produce a knife which will be less expensive to manufacture than the knife in use at the present time, which can be more easily sharpened, and which will tend to retain a sharp cutting edge as it wears in use; and it consists in the features of construction and combinations of parts hereinafter fully described and claimed.

In the accompanying' drawings, illustrating my invention, Figure l is a cross-section of a cutter-bar of a mower provided with knives made in accordance with my invention. Fig. 2 is a top plan view of a single knife as illustrated in Fig. l. Fig. 3 is a sectional view of the knife on the line 3 3 of Fig. 2. Fig. 4 is a broken horizon tal section, on a reduced scale, on the line 4 4 of Fig. 1.

The ordinary construction of reciprocating cutter` for mowers, reapers, and similar harvesting-machines is to mount a plurality of triangular knives side by side on a bar which is adapted to be reciprocated longitudinally. The knives project forward of the bar and are provided on their angular lateral sides with suitable cutting edges. The knives pass through recesses in what are termed iingers, and their lower faces rest and shear on hardened steel plates, which are inserted in said recesses of said fingers. The ordinary knife is made by punching' the required shape from sheet-steel and then grinding the upper sides of the lateral edges to a bevel to form the cutting edges. This latter step in the process is slow and expensive. The ordinary knife is chilled in use by the edge wearing away on the lower face, which renders the latter convex. The ordinary knife can be sharpened by grinding down the beveled edges; but the convex lower face cannot readily be ground, as this would reduce the thickness and render the knife too weak for further use. l

To overcome the above difliculties, I provide a knife A with flanged lateral edges B,

Specification of Letters Patent.

Application filed February 2, 1903. Serial No. 141,588.

Patented July 25, 1905;

which project below the body of the knife on a bevel and are ground on their lower faces parallel with the'plane of the body. Said edges B are adapted to rest on and coact with the shearing plates C, which are rigidly mounted in the fingers D.` Said fingers D project forward from the bar F beyond the path of said knives and are adapted to enter and divide the material being cut as the cutters are advanced into same. Said bar F is adapted to carry the reciprocating cutter-bar G, on which said knives A are rigidly mounted. The rear ends of said knives are adapted to rest on a shoulder H on said bar F in order to maintain said knives in a horizontal position. A longitudinal groove I is provided in said bar F to receive said cutter-bar G.

There are probably many ways in which the beveled flanges B might be produced; but I prefer to produce them as follows: The knifeblank having been punched as in the method of making the ordinary knife, I bend the lateral edges B downwardly at a suitable angle, preferably about thirty degrees. I then grind away the lower edges of the flanges B parallel with the body of the knife until I have produced cutting edges, as at J. This process of producing the knife is much simpler and cheaper than the process of producing the ordinary knife.

My knife as it wears will always remain in proper shearing contact with the shearingplates on account of the hollowed under surface produced by the iianged edges B, and as these edges wear on their lower faces they will tend to preserve a sharp cutting edge. However, should the cutting edge become dulled it can be sharpened readily and quickly by grinding back the lower faces of the flanged edges B or by grinding the upper beveled sides of the cutting edges as in the method of sharpening the ordinary knife.

I claim as my invention- 1. In a machine of the type set forth, the combination with the fingers having cut-away portions, shearing-plates rigidly mounted on the fingers and extending liush with the wall formed by said cut-away portions, a bar having a portion of its upper face cut away, said bar seating in said cut-away portions of the fingers and having its forward end abutting the wall formed by the cut-away portions of the ngers, said bar extending above the shearing-plates, a reciprocatory cutter-bar in said cut-away portion of the bar, knives rigidly mounted on said cutter-bar, and having down.-

ivardly-turned cutting edges bearing on the said shearing-plates,the rear ends of the knives extending beyond said cutter-bar and seating on said bar.

2. In a machine of the type set forth the in said bar and having its upper surface in alinement with the upper surface of said irstnamed bar and knives attached to said cutterbar and having Cutting edges extending down- Wardly and contacting with said shearingplates.

In testimony WhereofIaiX my signature in presence of two witnesses.

FRANK SCHUM. Witnesses:

RUDOLPH WM. LoTZ, E. F. WILSON.

Images