IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR SHARPENING THE KNIVES OF REAPING AND MOWING MACHINES
Year: 1884

page_text: We RALPH HENRY CHRISTOPHER NEVILE of Wellingore in the county of
Lincoln Esquire and EDWIN WHITWORTH of Sleaford in the same county, Engineer
do hereby declare the nature of the said invention for IMPROVEMENTS IN THE
METHOD OF AND APPARATUS FOR SHARPENING THE KNIVES OF REAPING AND
MOWING MACHINES to be as follows:-
The object of this invention is to improve the cutting apparatus used in Reaping
& Mowing Machines The usual practice is that when the knife or cutter has
become blunted, it is removed from the machine & re-sharpened either by a
grinding disc or by the file in most cases this is done by unskilled hands and the
requisite cutting angle which is so essential to the proper working of the machine
is soon lost and the cutting edges are all of different angles so that the draught of
the machine is much increased and the resulting work is not so well done.
To obviate this we in this invention place an automatic mechanical arrangement,
on the Reaping or Mowing, Machine itself, which is capable of resharpening the
knife or cutting arrangement, while the machine is at work. It is usual to have
two or more of these cutters or knives so that one may be re-sharpened, while
the other is in use, In this invention we thus dispense with the extra manual
aid usually required, and we preserve the proper cutting angle of the cutting
instrument.
One method of carrying out our invention is to employ a pair of grinding discs,
which may be of Emery, or other similar grinding composition, or stone, or discs.
carrying files or discs themselves files, or cutting arrangements; or one disc, or
grinder of suitable form may be used, In using a pair of grinding discs set at a
proper angle, which may be adjustable, we use a stand carrying the discs, which
are driven by suitable gearing from the driving mechanism of the machine, and to
this stand we impart a reciprocating motion, so that the knife or cutting instru-
ment, being placed in a suitable holder, is held in such a position that the
reciprocation of the stand carries the grinding or sharpening arrangement up.
and down the cutting edge of the knife or cutter, and when this is accomplished,
the knife or cutting instrument is moved a space, so that the grinding or sharpening,
may be repeated on the next part of the knife or cutting instrument, This movement
of the knife or cutting instrument is effected by mechanism operated by the driving

page_text: arrangement of the Reaping or Mowing machine itself, We also purpose to make
the movements of the mechanism within the control of the driver of the machine.
It will be observed that we do not confine ourselves to this precise arrangement
for attaining the desired end, but we purpose to use any convenient mechanical
arrangement by which the Reaping, or Mowing Machine shall be capable of
resharpening its own cutting instrument without interfering with its regular
work in Reaping or Mowing.
For example instead of causing the slide carrying the sharpening arrangement
to reciprocate, we may have it fixed, & impart to the knife itself an equivalent
reciprocal movement, & many other details may be modified in a manner easily to
be seen by any person acquainted with machinery, Or. we can if found more
convenient in practice use the automatic sharpening arrangement detached from
the machine, and driven by a fly wheel and treadle, or otherwise. This will still
obviate the inaccuracy and loss of power arising from the employment of unskilled
labour in the sharpening process.
Dated this doesnt sighth day of January 1984
R. H. C. NEVILE,
As Agent for Self and Edwin Whitworth.
We, RALPH HENRY CHRISTOPHER NEVILE of Wellingore Hall in the County of
Lincoln Esquire and EDWIN WHITWORTH of Sleaford in the same County Engineer
do hereby declare the nature of our invention for the said IMPROVEMENTS and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The object of this invention is to improve the cutting apparatus used by reaping
and mowing machines--The usual practice is to resharpen these by hand and in
most cases this being done by unskilled labour the requisite cutting angle is soon
lost & the draught of the machine is much increased-To obviate this we construct
an automatic arrangement which can either be attached to the reaping or mowing
machine or operated separately-One method of carrying out this our invention is
described in the following statement with its accompanying drawings-
Figure 1 is a plan of the grinding or sharpening arrangement as attached to a
mowing or reaping machine-Figure 2 is a side view of same.
Figure 3 is a front view and partial vertical section of the grinding or sharpening
arrangement and its gearing.
Figure 4 is a side view of the arrangement for holding the knife or cutting
instrument to be sharpened.
Figure 5 is a side view of our invention arranged as a separate machine.
On the shaft A Figs, 1, 2 & 3 is a. mitre wheel B which gears with another mitre
wheel C attached to this wheel is a bevel wheel D fig. 3, which gears into the two
bevel wheels E & F. The wheels C D E F are attached to the traversing carriage G
which is supported by the guide bars H & I and the mitre wheel B is connected to
the same carriage in such a manner that, when a traversing movement is imparted
to the carriage G. the mitre wheel B slides along the shaft A.

page_text: The wheels E & F. have their bearings on the carriage G and their shafts J K
carry at their other ends a pair of grinding wheels or dises, L & M adjusted to the
necessary angle.
The shaft A receives motion in this case from the driving mechanism of a mowing
machine through the wheels N & O.& it will be obvious that when the machine
is at work motion is imparted to the grinding discs L & M by the gearing above
described.
The shaft A carries at its other end, in addition to the mitre wheel B, a worm P
which gives motion to the worm wheel Q which is carried on one of the standards R.
This worm wheel has on its upper face a spiral projection S which meshes into
another worm wheel T carried on the shaft U, which has also at its other end a
wheel V-(This is a bevel wheel consisting of but few teeth and with a considerable
delay space) so that the effect of the rotation of the shaft A is to cause a slow
rotation of the wheel V through the worm gearing P. Q. T.
Gearing into the Bevel wheel V with a delay space is the pinion W which
receives an intermittent motion from it (and two of whose teeth are slightly smaller
than the others) and when not in motion is prevented from shifting by its flat or
delay space being on the corresponding flat on the wheel V-The pinion W is
attached to the shaft X carried on suitable bearings and has at its other end a spur
wheel Y which meshes into the Rack Z.
This Rack Z forms part of the arrangement for holding the knife or cutting
instrument A' which is being operated upon (see enlarged view Figure 4).
This holder slides upon a fixed carrier 2 which is supported by two radial
arms 3 & 4 which are pivoted at 5 & 6.
The knife or cutting instrument is clamped on the holder 1 as shown and when
the spur wheel Y is moved the rack & consequently the knife holder is traversed a
distance which is equal to a tooth or section of the cutting instrument being
operated upon.
The worm wheel T on the shaft A carries a crank pin 7 on its face from this a
connecting rod extends to the traversing carriage G which carries the grinding
arrangement and the rotation of the worm wheel T imparts a reciprocating motion
to it.
Attached to the sliding carriage G are the two lifting pieces 8 & 9 their object is
to lift the knife holder when the traversing motion has reached a certain distance.
Attached to the framework 10 are two fixed adjustable stops 11 & 11° upon each
of which a cutting edge of the knife or cutting instrument must ordinarily rest,
while the grinding wheels or discs L & M are being traversed against the edges of
an intermediate knife or section (These stops require to be of different levels as one
will bear upon an unsharpened and the other upon a sharpened section-The
surface of the stop 11 being on a level with the top of the grinding discs & the
surface of stop 11 being as much below the said level as is to be taken off at each
traverse) and when the return part of the reciprocation of the sliding carriage takes
place & the wheels L, M are out of contact with the knife or cutting instrument,
the two lifting pieces 8 & 9 come under the knife holder & lift it & consequently
the knife from off the stops.
The Spur wheel Y is then actuated & the knife holder is traversed the required
distance & the lifting pieces 8 & 9 being by the continued reciprocation of the
sliding carriage withdrawn from under the knife holder, it drops the edge of a knife
or section upon the stops.
The operation of the machine is as follows; a knife or cutting instrument a,;
requiring to be sharpened, is fixed in the holder 1, and one of its cutting edges rests
upon the stop 11*, the traversing grinders advance and return along the cutting
edges of a knife or section & then the knife is lifted off the stop and traversed the
required distance automatically, it then rests upon the stop 11 & is then locked in
that position by the pinion W having its flat against the delay space or flat of the
wheel V; the traverse of the grinders is repeated & so on until the whole of the
cutting instrument is sharpened.

page_text: It will be seen that by adjusting the stop 11 a greater or less amount can be
ground off the sections but when once adjusted they are ground automatically to
the required extent The knife holder 1 is held down by spring pressure the springs
are not shown in the drawing to avoid confusion.
Instead of making this automatic grinding machine stationary, & traversing the
cutting instrument upon it, the grinding arrangement may be made to traverse
upon the cutting instrument while the latter is attached to a fixed holder.
The reciprocating motion may also be imparted to the cutting instrument instead
of to the grinding discs-The reverse angle to that shown may also be used for the
grinding discs and the grinding arrangement may be made to stop itself when the
cutting instrument is finished by an ordinary stop motion.
Figure 5. shows our invention arranged as a separate machine and attached to a
stand when it may be operated by a treadle & fly wheel or otherwise.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that we
do not confine ourselves to the exact form and arrangement of the above machine
or machines as it is obvious that many details may be varied without departing
from its general principle but what we specially claim is
1st The application of any automatic arrangement to a reaping or mowing
machine whereby the said machine is made to sharpen one of its cutting instru-
ments while in motion.
2nd The application of an automatic instrument substantially as above described
whereby the cutting instruments of reaping and mowing machines can be properly
sharpened without the intervention of skilled labour.
R. H. C. NEVILE,
As Agent for Nevile and Whitworth.