US218580A - Improvement in scythes - Google Patents

Description

C. ROBY. Scythe.

Patented Aug. 172, 1879.

' into a Scythe-plate; and Fig. 4 represents the iron, which embraces an ed ge-bar of tool-steel,

' stiffness would be attained; but ascythe com- 'PATENT Orrrcn oHnIsTorHEa Roer, oEoHELMSFoRD, MASSACHUSETTS.`

` r`IMPROVEMENT IN SCYTHES.

specification foraingliaart ornatersratent No. 215,580, dated August 12, 1879,- appncation filed I December 14, 1878.

To all whom it may concern:

Be it known that I, CHRISTOPHER ROBY, of Chelmsford, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Scythes; and I do hereby declare the following specication to be such a full, clear, and exact description of the Same, when taken in connectionrwith the accompanying drawings, as will enable others skilled in the art to which my invention pertains to construct and use the same.

In said drawings, Figure l represents a mold or pattern, consisting of a bar of soft. steel doubled up so as to embrace a narrow bar or' tool-steel for the edge of the Scythe-blade, and a shortbarof soft steel to composeI in part the back of the blade. Fig. 2 represents, in plan and edge views, said mold or pattern after its parts have been'welded together and drawn out to constitute a Scythe-blank. Fig. 3 represents the saidblank after it has been formed finished Scythe, -of which Fig. 5 represents a sectional view.

Scythes as commonly constructed are formed of a body or back portion composed of Wroughtsaid parts being welded together', plated out, swaged into shape, and ground by the well` known processes. The product thus obtained requires that its body or back portion shall contain a considerable quantity of the wroughtiron composing it, in order to impart to lthe Scythe-blade the requisite degree of strength and stiffness, and thus necessarily forms a heavy, cumbersome, and unwieldy structure.

Ihe desirability of reducing the Weight and size of scythes, and thereby decrease the quantity and cost ot'the materials composing them, has long vbeen recognized by the manufacturer and trade, and attempts to make such a structurev have, prior to my invention, been unsuccessful.

It has been attempted to construct the Scythe Wholly of hard steel, whereby a lesser quantity of metal could be used, and great strength and posedof such metal becoming sprung and twisted in the hardening process would not endure the straightening process without breaking, and hence the older method of forming the Scythe-blade partly of tool-steel and partly of wrought-iron has continued to be practiced to the present time.

I overcome the defects in Scythes made by either of these methods, avoid the disadvantages of both, and produce a superior article by my improvement, which consists in forming the Scythe-blade wholly of steel by uniting an edge-bar of tool-steel to a body or back composed of soft steel, whereby a `lighthstrong, stift', and elastic blade is produced, that will sustain the necessaryhardening and straightening processes without danger of being ruptured.

In producing my improved Scythe-blade, I first prepare the mold or pattern, Fig. l, by binding a Short length, l 1, of soft steel upon itself in Such a manner as to embrace a bar, 2, ot tool-steel along one of its edges, in some cases (though not necessarily) also addinga bar, 3, of soft Steel to increase the quantity oi' metal at the back. This mold or pattern is then subjected to the well-known welding process, whereby the several parts are combined to form one homogeneous mass, which is drawn out, by rolling or otherwise, until the blank shown in Fig. 2 is produced. This blank is' then plated with dies under a vtrip-hammer until the Scythe-plate is shaped and formed as is shown in Fig. 3. This Scythe-plate is then swaged, so as to produce the back tlange., 4, and the heel 5. It is then hardened, then straightened, and finally ground and polished to produce a finished scytheblade.

The product thus constructed may, from the nature of the soit steel composing its back or body, be safely subjected to the straightening process necessary to remove the irregular form produced in the hardening operation without danger of breaking, cracking, or otherwise becoming injured. The great tenacity and strength of the steel entirely composing it enables a Scythe to be made of about one-fourth less quantity of metal than is required where iron constitutes the main-part of its body.

My improved Scythe-blade thus, while possessing great strength, becomes very light,

As a new article of manufacture, a scytheblade, the cutting-edge whereof is composed of tool-steel united to a body or back of soft steel, substantially as described.

ln testimony whereof' I have signed my name to this specification in the presence of two subscribing Witnesses.

CHRISTOPHER ROBY.

lVtnesses:

H. T. MUNsoN7 GEO. H. GRAHAM.

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