US90593A - Improvement in the methods of making serrated sickle-sections - Google Patents

Description

UNITED STATES PATENT QFFICE.

GEORGE F. SIMONDS, OF FITCHBURG, MASSACHUSETTS, ASSIGNOR TO THE 'SIMONDS MANUFACTURING COMPANY, OF SAME PLACE.`

IMPROVEMENT IN THE METHODS 0F MAKING SERRATED SICI-(I E-SECTIONS.-

Specification forming part of Letters Patent No. 90,593, dated May 25, 1869.

To all lwhom it may concern:

Be it known t-hat I, G. F. SIMONDS, of Fitchburg, in the county of Vorcester and State of Missaehusetts, have invented an Improvement in the Manufacture of Serrated Siekle- Sections; and I do hereby declare that the following, taken in connection with the dra-wings which accompany and form part of this specification, is a description of my invention sufficient to enable those skilled in the art `to practice it. v

In serratin g blanks for sickle-sections of harvesting-machines, the indentations or teeth are made upon, and so as to exten d across, the beveled edge of the blank, so that as the cuttingedge is ground down in sharpening', the serra-- tions of the cutting-edge are preserved.

As the indentations are first cut across the upper surface of the beveled edge of the blank, and not into the edge, like saw-teeth, the edge ofthe bevel has to be bent down, so that by facing off the edge to a plane ofthe under surface of the cutter the cutting-edge will be serrated.

The process heretofore practiced to obtain the serrated edge has been as follows: The bevel-edged blank is placed upon a suitable hat-surfaced bed, but with its beveled edge projecting over anincline upon the bed. By successive blows of a suitable cutter the upper surface of 4each beveled edge is now eut or toothed, each blow of the cutter not only mak-- ing a groove or indentation in the surface of the blank, but also bending down the edge at the blow-given point to the surface of the in'- cline over which the edge proj eets. When this cutting has been accomplished the under surface of the edge of the blank will be below the plane of the under surface ofthe blank. Such bent-down edge is then ground off to the plane of the under surface of the plate, the edge being thereby formed into a serrated cuttingedge.

Sickle-sections made by this process are imperfect, in that as the cutting-edge of the cutter has to be parallel to the surface of the incline down to which the edge is to be bent, the part of the beveled edge `back of the bend so formed is not out to the same depth as the part of the edge bent down, in consequence of which the serrations of the cutting-edge diminish in depth as the edge of the section is ground back in sharpening; and, also, in that as the bending action of the cutter does not extend to the point of the section, the edge of the section adjacent to such point protrudes beyoi 1d the points of the cutting-teeth, (when the edge has been ground off,) thereby impairing the cutting action of the section.

To obviate these objections I support the beveled edge upon a flat bed under the action ofthe cutter, the cutting-edge of the cutter being parallel to the surface of the beveled edge ofthe blank, thus causing the grooves to be cut to a uniform depth throughout each; and having thus effected the cutting, I remove the blank from the flat bed, and bend down the whole edge of the bevel at once, (by any suitable mechanism,) after which the bent edge is ground off .to a plane with the bottoni surface of the plate, thus making the serrated cutting-edge. Itis in this process for producing the serrated edge that my improvement consiststhat is to say, a process consisting in first cutting the grooves across the beveled surfaces of the section, next bending down at one operation the edge of the bevel, and, lastly, grinding off the edge thus bent down to a plane with the under surface of the blank plate.

The drawings represent a sickle-section made in accordance with my process, and also a section made by the old process, above described.

A shows a top view of one of my sections finished. B is a section, showing the edge after being bent and before being ground 0E. C is a similar section, showing the iinished edge. D is a top view of the iinished section made by the old process described. E shows the edge of such section before it is ground off.

In my process, the blank being supported at its beveled edge upon a fiat bed, each groove .is cut to a uniform depth throughout, as seen at A, and at B and C, and the entire length of edge on either side ofthe point ofthe section being then bent down, as seen at B, and the bent edge being then ground down to the plane of the under surface of the plate, the cuttingedge will be left as seen at A and C, or so that, as the plate is reduced in thickness in resharpening, the serrations or teeth of the cutting-edge arekept of the same size, whereas,

doWnthe Whole edge of the bevel, and, finally,

grinding oi the edge, substantially as described.

2. Sickle-sections made by the improved process described.

GEO. F. SIMONDS.

Witnesses:

J. B. CROSBY, FRANCIS GOULD.

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