IMPROVEMENTS IN APPARATUS FOR SHARPENING THE BLADES OR KNIVES EMPLOYED IN MOWING AND REAPING MACHINES
Year: 1867

page_text: Lancaster, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
SHARPENING THE BLADES OR KNIVES EMPLOYED IN MOWING AND REAPING
MACHINES."
Sealed the 24th March 1868, and dated the 1st October 1867.
PROVISIONAL SPECIFICATION left by the said William Mitchell at the
Office of the Commissioners of Patents, with his Petition, on the 1st October
1867.
I,. WILLIAM MITCHELL, of Manchester, in the County of Lancaster, do
hereby declare the nature of the said Invention for" IMPROVEMENTS IN APPARATUS
FOR SHARPENING THE BLADES OR KNIVES EMPLOYED IN MOWING AND REAPING
MACHINES," to be as follows:-
My Invention relates first to an apparatus driven by gearing and manual
labor, and secondly to an apparatas to be used in a similar manner to a filo
both being designed for sharpening the angular knives employed in mowing
and reaping machines, and particularly for entering and sharpening the inner
angles or corners of such knives.

page_text: The improvements consist,
First. In the use and adaptation of a rotating disc or circular plate mounted
on a shaft inclined from the vertical so as to place the disc at an angle;
upon this disc a covering of emery composition is laid, tapering from the
periphery towards the centre, and the whole is driven by strap and pulley
or gearing. The peculiar position and form of surface and narrow periphery
of this emery covered disc enables the operator to grind or sharpen each
edge of the angular knives from the "point" to the "root" evenly without
leaving the inner angle unground as by the present method employed for
sharpening.
Secondly. The improvements consist in the adaptation and use of a similar
tapered emery surface which is to be placed on a metal or wood foundation
and shaped and used like a file, one side of the emery file being narrow and
the other wide; the back or foundation being also tapered (the cross section
being like a wedge) and the "lang" or handle being placed out of the centre
and nearer one side of the file. The emery files thus formed are to be used
in pairs right and left hand" and are specially adapted for entering the
angles and sharpening the said angular knives.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Mitchell in the Great Seal Patent Office on the
1st April 1868.
C
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MITCHELL, of Manchester, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of October, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirty-first year of Her reign.
did, for Herself, Her heirs and successors, give and grant unto I, the said
William Mitchell, Her special license that I, the said William Mitchell, my
executors, administrators, and assigns, or such others as I, the said William
Mitchell, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR

page_text: SHARPENING THE BLADES OR KNIVES EMPLOYED IN MOWING AND REAPING MACHINES,"
upon the condition (amongst others) that I, the said William Mitchell,
my executors or administrators, by an instrument in writing. under my,
or their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said William Mitchell, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement and accompanying Drawings (that is to say):-
My Invention relates first to an apparatus driven by gearing or manual
labor, and secondly to an apparatus to be used in a similar manner to a file
both being designed for sharpening the angular knives employed in mowing
and reaping machines, and particularly for entering and sharpening the inner
angles or corners of such knives.
The improvements consist,-
First. In the use and adaptation of a rotating disc or circular plate mounted
on a shaft inclined from the vertical so as to place the disc at an angle:
upon the disc a covering of emery composition is laid, tapering from the
periphery towards the centre, and the whole is, driven by strap and pulley
or gearing. The peculiar position and form of surface and narrow periphery
of this emery covered disc enables the operator to grind or sharpen each
edge of the angular knives from the "point" to the "root" evenly without
leaving the inner angle unground as by the present method employed for
sharpening.
'
Secondly. The improvements consist in the adaptation and use of a similar
tapered emery surface which is to be placed on a meial or wood foundation
and shaped and used like a file, one side of the emery file being narrow and
the other wide; the back or foundation being also tapered (the cross section
being like a wedge) and the "tang" or handle being placed out of the centre
and nearer one side of the file. These emery files thus formed are to be used
in pairs "right and left-handed" and are specially adapted for entering the
angles and sharpening the said angular knives.
In order that the Invention may be better understood and explained in
detail I have hereunto attached a Sheet of Drawings made upon a scale of
about three inches to the foot.

page_text: Fig. 1 represents a front elevation of the improved apparatus to bo
employed for sharpening the knives or cutters of reaping or mowing
machines; Fig. 2 represents a plan view of the same; Figs. 3, 4, and 5,
represent various modifications or arrangements of the improved sharpener
which are shewn as examples, and Figs. 6 and 7 represent respectively a
plan and an end sectional view of a hand file to be employed for similar
purposes.
In Figs. 1 and 2 a is a disc or circular plate mounted on the shaft b
which is inclined from the vertical, and so arranged and supported in the
framing as to place the disc a in an angular or inclined position. Upon
the upper surface of the disc a a covering of emery or other grinding com-
position is laid, tapering from the centre or ring d towards the periphery,
so as to form an angular or bevilled grinding or sharpening surface;
the diagonal shaft b imparting rolation to the disc is actuated by the
treddle through the medium of the gearing or by shaft and pulley,
the knife k during the operation of sharpening being supported on the
rails or bars a.
In Figs. 3 and 4 the grinding or sharpening disc a is mounted on a central
axis h, the periphery of the disc when coated or covered with emery com-
position being in the form of a double angular surface tapering from the
centre of the periphery towards the edges, as seen in section Fig. 4.
In Fig. 5 another modification is shewn, the disc a having the emery or
grinding surface applied and attached to the surface of the disc and is tapered
to the required angle as shewn.
In Figs. 6 and 7 the tapered surface of emery is applied to the surface of a
tapered file blank and is employed as an ordinary file.
I would remark that the discs or wheels may be composed wholly of the
emery or other grinding composition if desired.
Having now described the nature of the said Invention together with the
method of carrying the same into practical effect, I wish it to be distinctly
understood that I claim,-
First. The employment and use of a revolving disc or circular plate placed
at an angle, the grinding surface being covered with emery or other grinding
composition.
Secondly. The use of a file made as described.
And, thirdly. The employment and use of revolving discs or wheels having
angular, bevilled, or tapered surfaces to enable the thin edge thereof to enter
and grind the inner angles of the knives of reaping and mowing machines

page_text: escribed, set forul, au
attached.
In witness whereof, I, the said William Mitchell, have hereunto set
my hand and seal, this Thirty-first day of March, in the year-of our
Lord One thousand eight hundred and sixty-eight.
Witnessed by
JNO. HUGHES,
Clerk to Jno. Davies & Son,
Office for Patents,
4, St. Ann's Sq.,
Manchester.
WILLIAM MITCHELL. (L.s.)