IMPROVEMENTS IN CHAFF-CUTTING MACHINES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by the said Edmund Winder
Otway at the Office of the Commissioners of Patents, with his
Petition, on the 2nd March 1866.
I, EDMUND WINDER OTWAY. of Reading, in the County of Berks,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN CHAFF-CUTTING MACHINES," to be as follows:-
These improvements in chaff-cutting machines according to my Inven-
tion consist, first, in forming on the outer surface of chaff-cutter knives
ridges or grooves for the purpose of giving to the knives a serrated edge
instead of a smooth edge as has been usual heretofore.
This ridged or
grooved surface being on the outside of the knife. and the knife being
ground or sharpened on the inside, gives to the knife a serrated edge,
which acts upon the material to be cut like a saw with fine teeth. This
arrangement also prevents the cutting away of the mouth-piece of the chaff-
cutter so much complained of. the constant sharpening of the knives being
[Price 8d.]

page_text: avoided they will wear much longer than the ordinary smooth edged
knives now in use, much less power being required to drive the machine.
The second improvement in chaff-cutting machines according to my
Invention consists in the means adopted for sharpening the knives or
cutters of such machines. For this purpose I take a block of stone or
a prepared block of emery or other suitable composition of the width of
the mouth-piece of the machine, and fasten it in the mouth-piece by
pressure or by other suitable means; this block projects slightly beyond
the face of the mouth-piece, so as to press against the knives; I then
turn the wheel on which the knives are fixed the reverse way, thus grind-
ing the knives against the cutting block in the mouth-piece until the knives
are ground or sharpened. Thus any one can sharpen the knives without
removing them from the chaff-cutter, and without the danger of cutting
themselves by trying to sharpen the knives in the usual way in their places.
This arrangement causes the knives to retain a fine surface corresponding
to the surface of the mouth-piece, and prevents the unequal notched
surface commonly the case with knives sharpened in the usual way. It
also prevents the mouth-piece from being cut away to the injury of the
machine, and saves considerable expense in sharpening the knives.
The third part of these improvements consists in causing the top feed
roll of the chaff cutter to rotate at a slower speed than the bottom feed
roller, to compensate for the excess of friction caused by the bottom of the
straw box, and thus prevents "winding" in the top feed roll (that is,
choking and bursting the machine); for having less friction to overcome
the top roll is liable to carry the material round with it, and thus cause
choking and bursting, it also prevents the machine feeding unequally and
giving unequal lengths of chaff.
SPECIFICATION in pursuance of the conditions of the Letters Patent.
filed by the said Edmund Winder Otway in the Great Seal Patent
Office on the 1st September 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
WINDER OTWAY. of Reading, in the County of Berks, Engineer. send
greeting.

page_text: Lord One thousand eight hundred and sixty-six, in the twenty-ninth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Edmund Winder Otway. Her special licence that I,
the said Edmund Winder Otway, my executors, administrators, and assigns,
or such others as I. the said Edmund Winder Otway. my executors.
administrators, and assigns, should at any time agree with, and no others,
from time to time and 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 CHAFF
CUTTING MACHINES," upon the condition (amongst others) that I, the said
Edmund Winder Otway, my executors or administrators. by an instru-
ment 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 Edmund Winder Otway, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say:-
These improvements in chaff-cutting machines according to my Inven-
tion consist, first, in forming on the outer surface of chaff-cutter knives
ridges or grooves for the purpose of giving to the knives a serrated edge
instead of a smooth edge as has been usual heretofore. This ridged or
grooved surface being on the outside of the knife, and the knife being
ground or sharpened on the inside, gives to the knife a serrated edge,
which acts upon the material to be cut like a saw with fine teeth. This
arrangement also prevents the cutting away of the mouth-piece of the chaff-
cutter so much complained of, the constant sharpening of the knives being
avoided they will wear much longer than the ordinary smooth edged knives
now in use, much less power being required to drive the machine.
In carrying out the first part of my improvements I prefer to make the
ridges or grooves on the back or outer surface of chaff-cutter knives of a
V form or acute angle extending along the surface of the knife at an angle
of about thirty-five degrees to the perpendicular of the cutting edge, as
will be better understood by reference to Figure 1 of the Drawing
hereunto annexed, which shows a side view, and Figure 2 a section of a
chaff-cutter knife a, having ridges or grooves cut or formed thereon

page_text: according to this part of my Invention. Knives or cutters of this improved
construction may be made entirely of steel, or of steel and iron combined.
or they may be made in two parts with an iron back having a steel cutting
edge attached thereto so as to be removeable when required. 1 prefer to
form the ridges or grooves by means of a chisel in like manner to that
employed in the, manufacture of files, but I do not confine myself to any
particular method of forming such grooves. The knife or cutter a is
ground on the inner face, the ridges or grooves thus producing a serrated
edge thereto, the bottom of the grooves and the top of the ridges
forming a series of sharp or diamond pointed teeth, and the angle at which
the ridges are cut or formed causes a hooking or drawing action in cutting
with a knife having a spiral or gliding movement of the cutting edge. The
form or shape of the knives or cutters which I prefer to employ in carrying
out this part of my improvements is such that they will have a gliding or
spiral action in cutting, and so that there will be about two inches of
perpendicular action of the knife to about one-quarter of an inch in
horizontal action or progress in cutting this form and action of the knife
causes the points of the teeth formed by the serrations to penetrate the
cylinders of the straw. splitting it into shreds, and consequently making it
soft, thus rendering it more valuable and nutritious. In grinding the
serrated knives or cutters on the inner surface, the serrated edge is ground
slightly back, the extreme points of the teeth being thus set off at a slight
angle from the mouth-piece, so that when the knives are set against the
mouth-piece a of the chaff-cutter, the smooth portion of the knife at a
only is in contact with the month-piece of the machine. This arrangement
prevents the month-piece from being cut into notches (as is the case with
smooth edged knives) and also economizes the power otherwise absorbed
by friction. The effect of ordinary smooth edged knives is to cut the
straw without splitting the cylinders, and in cutting short lengths of chaff
the straw is frequently pushed before the edge of the knife which passes
over the straw without cutting it or only partially cutting it. The
friction of the straw sometimes causes the knives to heat, "buckle" and
cut the mouth-piece in notches, this objection is obviated by employing
knives or cutters with serrated edges according to my improvements, the
sawing action of which draws the straw towards the cutter, and I have found
that the movement of about two inches of teeth or cutting edge of the
knife acting upon one-quarter of an inch of the surface of the straw in the
mouth-piece prevents the straw from passing the knife without being cut.
Chaff-cutting machines furnished with knives of this construction with
✗

page_text: serrated edges can be driven at a greater speed with much less power than
those having smooth edged knives.
The second improvement in chaff-cutting machines according to
my Invention consists in the means adopted for sharpening the knives
or cutters of such machines. For this purpose I take a block of
stone or a prepared block of emery or other suitable grinding compo-
sition of the width or nearly the width of the mouth-piece of the
machine and fasten it in the mouth-piece by pressure or by other
suitable means when the knives require sharpening; this block projects
slightly beyond the face of the mouth-piece so as to press against the
knives, I then turn the wheel on which the knives are fixed the reverse
way, thus grinding the knives against the cutting block in the mouth-piece
until the knives are ground or sharpened; thus any one can sharpen the
knives without removing them from the chaff cutter and without the
danger of cutting themselves by trying to sharpen the knives in the usual
way in their places. This arrangement causes the knives to retain a true
surface corresponding to the surface of the mouth-piece, and prevents the
unequal notched surface commonly the case with knives sharpened in the
usual way; it also prevents the mouth-piece from being cut away to the
injury of the machine, and saves considerable expense in sharpening the
knives. The manner in which, this part of my improvements is carried
into practice will be clearly understood by examining Figures 3 and 4 of the
Drawing hereunto annexed, which show two views of a chaff-cutting machine
having a block of stone b, or other suitable grinding substance placed in
the mouth-piece c when the knives or cutters a, a. require sharpening, the
straw box and mouth-piece being previously cleared out for this purpose.
Figure 5 shows a separate view of the block b, and clip or holder b', with
adjusting screws b to set up the grinding surface correctly with the edge
of the cutters. Before commencing to grind, the setting screws of the
cutters should be slackened, and then by turning the fly wheel a' the
reverse way the knives will very soon be ground to an edge with a true
surface corresponding with the face of the mouth-piece.
The third part of these improvements consists in causing the top feed roll
of the chaff cutter to rotate at a slower surface speed at the periphery than
the bottom feed roller, to compensate for the excess of friction caused by
the bottom of the straw box, and thus prevents "winding" in the top feed
roll (that is, choking and bursting the machine); for having less friction
to overcome the top roll is liable to carry the material round with it and

page_text: thus cause choking and bursting: it also prevents the machine feeding
unequally and giving unequal lengths of chaff.
I have not thought it necessary to show any particular arrangement
of mechanism for actuating the feed rollers in accordance with this part of
my improvements in chaff-cutting machines, as any ordinary mechanic will
readily arrange the driving gear of such machines, so as to cause the
top feed roller to travel at a slower surface speed at the periphery than
that of the bottom feed roller, and thus carry into practice this part of my
improvements.
In witness whereof, I, the said Edmund Winder Otway, have hereunto
set my hand and seal, this Thirtieth day of August, in the year
of our Lord One thousand eight hundred and sixty-six.
Witness,
J. G. TONGUE,
Patent Agent,
EDMUND, W. OTWAY. (L.S.)
34, Southampton Buildings,
Chancery Lane, W.C.