Year: 1888

page_text: I WILLIAM ST. GEORGE ELLIOTT of 39 Upper Brook Street, Grosvenor Square in
the County of Middlesex, Surgeon Dentist and Doctor of Medicine do hereby declare
the nature of this invention to be as follows :-
My invention relates to the knives of reaping or analogous machines for cutting
grain grass or for other work.
As at present constructed the knives are flat and have a chisel edge which when
dull and blunt with work require to be reground or sharpened.
The object of my invention is to obviate this disadvantage and to this end my
invention consists in so stamping or shaping the knives as to give them a hollow or
other form so that the edges of same passing over the opposite knives will be self
sharpening.
To further assist in this self sharpening process, the outer face of the blade may be
hardened either by tempering, chilling, case hardening, steeling or in other ways facing
with a harder metal so that as the edges of the cutter grind away, the inner side of
same being of softer metal wears somewhat more quickly than the outer skin or cutting
edge, practically keeping said edge in a sharpened condition.
Dated this 1st day of November 1888
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Agent for the Applicant.

page_text: Improvements in Reaping Machine or other Knives or Cutters.
I, WILLIAM ST. GEORGE ELLIOTT, of 39 Upper Brook Street, Grosvenor Square in
the County of Middlesex, Surgeon Dentist and Doctor of Medicine, do hereby declare
the nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention relates to the knives of reaping or analogous machines for cutting
grain, grass, or for other work.
As at present constructed the knives are flat and have chisel edges which when dull
and blunt with work require to be reground or sharpened.
The object of my invention is to obviate this disadvantage, and to this end my
invention consists in so stamping or shaping the knives as to give them a hollow or
other form so that the edges of same passing over the opposite knives or fingers will
he self sharpening.
To further assist in this selfsharpening process, the outer face of the blade may be
hardened either by tempering, chilling, case hardening, steeling, or in other ways
facing with a harder metal, so that as the edges of the cutter grind away, the inner
side of same being of softer metal wears somewhat more quickly that the outer skin or
cutting edge, practically keeping said edge in a sharpened condition.
To clearly explain my invention reference is made to the accompanying drawings
in which
Fig. 1 represents a top view of one of the cutters of a harvester constructed according
to my invention.
Fig. 2 represents a transverse sectional view of the same on line a x, Fig. 1.
Fig. 3 represents a top view of a modified construction of cutter.
Fig. 4 is a transverse sectional view of the same on line a a, Fig. 3.
Figs. 5 and 6 represent similar views of a third modification.
Referring to the drawings by letter, A, Figs. 1 and 2, indicates the knife or cutter,
the cutting-edge of which is of the usual angular configuration, the body consisting of
a hollow or concavo-convex shell, as indicated. This cutter-shell, is made preferably of
metal stamped or bent into the proper shape in any suitable manner; but it may be
inade of cast metal if desired.
The outer side of the shell is however preferably case-hardened as indicated at B,
the interior side C remaining soft, so that the inner or softer portions of the shell may,
by abrasion, wear more rapidly than the outer hardened portions which forms the
cutting edges of the cutter, thereby keeping the edges sharp and keen.
Instead of constructing the cutters of case-hardened soft metal as above described,
they may be composed of an exterior thin steel shell B, re-enforced by an interior shell
of soft metal C, as shown in Fig. 4. In some instances the steel shell B may be open
at the centre and be replaced by the soft metal C, as shown in Figs. 5 and 6, the hard
portion in this case being practically only the cutting edge.

page_text: In the drawings the cutters are shown triangular in plan, but it is evident that they
may be otherwise shaped without departing from the spirit of my invention, the
essential feature of which is a hollow cutter with or without an exterior hard portion
or cutting edge.
The advantages of my cutter-shell over the ordinary flat metal cutters are obvious,
in that the latter must be sufficiently heavy or thick to stand the strain incident to
usage. and when so made, the cutting edge being thick, will not wear uniformly, and
the exterior portion of the edge will" round up" from wear before the interior has
worn sufficiently to keep the exterior of the edge in contact with the guard-finger
edges. By my invention the cutters even when made of one quality of metal are
sufficiently strong and retain their cutting edge, though I prefer to use the two
qualities of metal, as the softer interior portion wearing more quickly than the outer
hard portion, leaves the thin narrow edges of the latter as the cutting edges,
and these wearing equally down, close contact with the guard-fingers is preserved.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is -
1. A knife for reapers and analogous machines, hollow in form, and having bevelled
or chisel edges, substantially as and for the purposes described.
2. A knife for reapers and analogous machines hollow in form, the outer surface or
cutting edge of which is of harder metal than the interior or body of same and having
bevelled or chisel edges, substantially as and for the purposes described.
Dated this 14th day of February 1889.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Applicant's Agent.