IMPROVED MACHINERY FOR SHARPENING SAWS
Year: 1866

page_text: LETTERS PATENT to John Parry, of Llanberis, in the County of Carnarvon,
Manager of Slate Works, and Richard Morris, of Cwm-y-glo, in the
same County, Mechanic, for the Invention of "IMPROVED MACHINERY FOR
SHARPENING SAWS"
PROVISIONAL SPECIFICATION left by the said John Parry and Richard
Morris at the Office of the Commissioners of Patents, with their Petition,.
on the 1st August 1866.
We, JOHN PARRY, of Llanberis, in the County of Carnarvon, Manager, of
Slate Works, and RICHARD MORRIS, of Cwm-y-glo, in the same County,
Mechanic, do hereby declare the nature of the said Invention for "IMPROVED
MACHINERY FOR SHARPENING SAWS," to be as follows:-
This Invention relates to improved machinery for effecting the sharpening
of circular saws automatically by the aid of a reciprocating file or cutter. The
file is held in a clamping frame which slides in vertical guides in standards of
the main framing of the machine. This clamping frame receives an up-and-
down motion from the connecting rod of a crank shaft, which shaft carries
also at one end a slotted crank arm parallel with the crank, but on the
opposite side of the axis of the shaft, for the purpose of transmitting a
reciprocating motion to the table which carries the saw. The slot of the arm
carries an adjustable pin over which slides the looped or slotted end of a
connecting rod notched at its other end so as to drop over a pin carried by

page_text: a rock lever and furnished with a handle for lifting it off the pin for re-
adjustment. This rock lever is hinged to a bracket on the base of the
machine, and it is connected by an adjustable pin to a rod which connects it
with an arm bolted to the sliding table on which the circular saw to be
sharpened is mounted. A central clamping screw passes through the table
and through the centre of the saw, and by means of a disc of wood (somewhat
smaller in diameter than the saw) and a nut secures the saw to the table.
Affixed transversely to the table is an arm that carries a block of lead for
the part of the saw near the cutter to bear upon. This arm carries at its
extremity a bell-crank lever, one limb of which is connected by a jointed rod
with a slotted bracket bolted to the side framing. The other limb of the
crank lever carries a double-toothed pawl, which is caused to engage by the
pressure of a spring with the teeth of the saw and give it an axial motion
and bring the teeth in succession in a line with the cutter. The jointed
coupling rod is made adjustable both longitudinally and laterally in order to
determine the amount of rocking motion the crank lever shall receive from
the movements of the sliding table, which as before explained carries its
fulcrum pin. The amount of motion will depend on the size of the saw teeth
and whether the teeth are to be brought consecutively under the action of the
cutter or every other tooth (the latter arrangement being necessary as is
well understood when a chamfer is to be given to the teeth). The traverse
forward of the table to bring the saw under the action of the cutter is
regulated by a stop nut, and in its backward traverse to clear the saw from
the cutter during its upward movement it bears against a coiled spring which
gives it a tendency to return to its advanced position. For giving a bevil
to the teeth it will be necessary to tip the saw, which may be effected by
mounting the saw table or support on journals that will allow of its rocking
to bring the saw to any desired angle with the vertical cut of the file. In
this case every other tooth is first to be sharpened, and then the position of
the saw being reversed the sharpening is to be completed.
Another mode of working the pawl is to mount it on a radius arm rocked
by the reciprocating table, and having for its fulcrum the clamping screw which
passes through the reciprocating table and carries the saw. Pivotted to the
table is a slotted rocking lever which receives as its fulcrum a pin that is
adjustable in a groove in the fixed framing. The position of this pin
determines in the following manner the length of throw of the radial arm
that carries the pawl. Connected with the free end of the rock lever is a rod
that is jointed to a second radius arm, and this arm is connected by a screwed
coupling rod to the arm that carries the pawl. This arrangement admits of

page_text: being applied to either side of the machine so as to reverse the direction of
rotation of the saw.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said John Parry and Richard
Morris in the Great Seal Patent Office on the 11th February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
PARRY, of Llanberis, in the County of Carnarvon, Manager of Slate Works,
and RICHARD MORRIS, of Cwm-y-glo, in the same County, Mechanic, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of August, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said John Parry and Richard Morris, Her special licence that we, the said
John Parry and Richard Morris, our executors, administrators, and assigns, or
such others as we, the said John Parry and Richard Morris, our 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 "IMPROVED MACHINERY FOR SHARPENING SAWS," upon the
condition (amongst others) that we, the said John Parry and Richard Morris,
our executors or administrators, by an instrument in writing under our, or their,
or one of their hands and seals, should particularly describe and ascer-
tain 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 we, the said John Parry and Richard Morris, do
hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to say) :-
This Invention relates to improved machinery for effecting the sharpening

page_text: of circular saws automatically by the aid of a reciprocating file or cutter.
The file is held in a clamping frame which moves up and down in vertical
guides attached to the standards of the main framing of the machine. This
clamping frame receives an up-and-down motion from the connecting rod of
a crank shaft, which shaft carries also at one end a slotted crank arm parallel
with the crank, but on the opposite side of the axis of the shaft, for the purpose
of transmitting an intermittent motion to the table which carries the saw.
The slot of the arm carries an adjustable pin, over which slides the looped or
slotted end of a connecting rod notched at its other end so as to drop over a
pin carried by a rocking lever, and furnished with bandle for lifting it off
the pin for re-adjustment; this rocking lever is hinged to a bracket on the
base of the machine, and it is connected by an adjustable pin to a rod which
connects it with an arm bolted to the sliding table on which the circular saw
to be sharpened is mounted. A central clamping screw passes through the
table and through the central hole of the saw, and by means of a conical disc
or block of wood (somewhat smaller in diameter than the saw) and a nut the saw
is firmly secured on the table. Affixed transversely to the table is an arm that
carries a block of lead which forms a bed for that part of the saw which is
near the cutter to bear upon; this arm carries at its extremity a bell-crank
lever, one limb of which is connected by a jointed rod with a slotted bracket
bolted to the side framing; the other limb of the bell-crank lever carries a
double-toothed pawl, which is caused to engage by the pressure of a spring
with the teeth of the saw and to give it an axial motion and bring the teeth
in succession in a line with the reciprocating cutter. The jointed coupling
rod is made adjustable both longitudinally and laterally in order to determine
the amount of rocking motion the crank lever shall receive from the move-
ments of the sliding table, which, as before explained, carries its fulcrum pin.
The amount of motion will depend on the size of the saw teeth, and whether
the teeth are to be brought consecutively under the action of the cutter or
every. other tooth (the latter arrangement being necessary as is well under-
stood when a chamfer is to be given to the teeth), as for saws which are used
for cutting wood. The traverse forward of the table which brings the saw
under the action of the cutter is regulated by a stop nut, and in its backward
traverse (to clear the saw from the cutter during its upward movement) it
bears against a coiled spring which gives it a tendency to return to its
advanced position. For giving a bevil to the teeth it will be necessary to tilt
the saw on one side, which may be effected by mounting the saw table or
support on journals that will allow of its being rocked so as to bring
the saw to any desired angle with the vertical cut of the file; in this case

page_text: every other tooth is first to be sharpened and then the position of the saw
being reversed the sharpening is to be completed.
Another mode of working the pawl is to mount it on a radius arm which
is rocked by the reciprocating table, and has for its fulcrum the clamping
screw which passes through the reciprocating table and carries the saw.
Pivotted to the table is a slotted rocking lever, which receives as its fulcrum
a pin that is adjustable in a groove in the fixed framing; the position of this
pin determines in the following manner the length of throw of the radial arm
that carries the pawl:-Connected with the free end of the rocking lever is
a rod that is jointed to a second radius arm, and this arm is connected
by a screwed coupling rod to the arm that carries the pawl. This arrange-
ment admits of being applied to either side of the machine so as to reverse
the direction of rotation of the saw.
In order to admit of saws of various diameters being sharpened a longi
tudinal slot is made in the table to receive the clamping screw.
In the accompanying Drawing Fig. I is a side elevation of the machine;
Fig. 2 is a plan view, and Fig. 3 an end elevation.
a, a, is the framework, which is made of iron; b, b, is a wooden bench or
foundation on which the iron frame a, a, is supported; e, e, is the crank shaft,
and d, d, the crank to which is jointed the connecting rod d' whereby the
slides and jaws c, c, are moved up and down; f is a file or cutter fixed
between the jaws c, c, and 9 is the saw which is to be operated on, and is
placed over the centre pin or axle i; h is a conical block of wood which,
when screwed down, steadies or holds the saw firmly; the pin or axle i carries
a friction plate i', and is moveable in the slot k, k, for setting various sized.
saws to the cutter f; y is an arm screwed to the slide k, and is connected to
the lever wat the point x. A slotted arm t revolves on the crank shaft e,
and is fixed opposite to the crank d; this slotted arm with the crank moves
in the direction of the arrow e¹. A rod u¹ connects the arm t and the lever w
at the points u and w¹, which are moveable; by adjusting these points any
required change in the length of stroke delivered by the pin u may be made;
w is a lever whose fulcrum is at a¹; the pin x on this lever is connected by
the rod to the end of the arm y; k" is a stud fixed to the slide k', through
which the screw z runs freely; z is a screw which has its female thread in the
boss at ; z¹ is a spring which operates on the slide k¹ by pressing against
the stud ; is a nut on the screwed pin z for regulating the length of the
movement of the stud ; is another arm which is serowed to the slide k¹,
and is provided with a bed or packing of lead which supports the edge of the
saw plate close to the file; n is a centre pin carried by the arm l, and m, m,

page_text: is an elbow whose centre is at n; q is a sliding boss set by the screw q¹ to
adjust the throw of the pawl p. A bracket s, s, is screwed to the framework,
and carries at the point s¹ the slide 8 and moveable boss s³, which are
adjustable by the screw *; r is a connecting rod between the points s* and q;
and o is a joint at one end of the elbow m. The pawl p works on the centre o,
and is provided with two points which advance the saw teeth to their position
for each successive cut of the file.
In the Drawing the machine is shewn in its position at the commencement
of the file cut, the saw tooth being also ready in its place with the pressure of
the spring ¹ upon it through the medium of the slide k. When motion is
given to the crank d the slides c which carry the file f descend and give
the requisite form to the tooth of the saw. The crank & having arrived at
the lowest point in its revolution the slotted crank t carrying the pin w will
have made a semi-revolution in the direction of the arrow, and will begin to
act or push against the rod u in the direction of the arrow u", which will
cause the point w³, with the lever w to which it is screwed, to move back
(more or less, according to the distance of the pin u from the centre of the
crank shaft e), and carry with it the slide by means of the army and
connecting rod x" and pin x. The saw will thus be cleared any required
distance from the file inmediately the cut of the file is completed, and will
keep it free from the back drag of the file until the crank d is again in the
position shewn in Figures 1 and 3; but the retiring motion of the slide k¹
will also, through the arm 1, have caused the centre pin n to move in the
direction of the arrow n¹, and this pin n being the middle of the elbow m will
cause the point o to advance in the direction of the arrow o¹, and cause the
pall p to move its point from 2 to the red lines at 3, and thus carry the next
tooth of the saw into position for the ensuing descent of the file. When this
has been effected the crank pin u will again have arrived at the point where
it ceases to act on the rod u¹, the long slot u" allowing the pin u to traverse
its semi-revolution without any action longitudinally on the rod u'. Thus
one revolution will be completed and a second one about to commence, as
shewn in Figures 1, 2, and 3.
The self-acting gear of this machine can also be made available for forming
or sharpening saw teeth at any angle to the plate. To effect this the body of
the machine which carries the saw and all the parts (except the crank shaft
and file) are to be made movable on an axis or cradle so as to place the saw
plate at any required angle with the vertical cut of the file; in this case the
saw can have every other tooth sharpened when at one angle, and the
remaining teeth when set at the opposite angle.

page_text: Fig. 4 is a plan view representing another method of working the pawl.
The centre of the saw is carried on the shaft c, which is movable in the slot k
for adjustment according to the size of saw plate, as in Figures 1, 3; f is the
file; g, the saw; h is one end of a lever carried by the slide k in the direction
of the arrow n; o is the fulcrum, which is moveable in a groove in the frame-
work towards the point p, which is moveable in a slot nearer to or farther
from the fulcrum o, for adjusting the throw of the pawl. The point p causes
the points 9 and r and the points carrying the pall t to move in the direction
of the arrows u¹ and r¹. When the slide k is moved in the direction of the
arrow at n the pawl can be made to deliver every tooth or every other tooth
in position for the action of the file as required. For inclining the saw at any
angle to the vertical cut of the file the body of the framework carrying the
saw and the apparatus which moves the pawl is supported by an axle or
cradle in its place, so that it can be moved to any required angle to the vertical
file. The whole apparatus for moving the pawl may be placed on the other
side of the framing and made to work in the opposite direction from that
shewn in the Drawing, as indicated by the dotted lines and centres at x, Fig. 4,
and the saw plate may be inverted if desired, in order to obtain other means
of producing the angular form to the saw teeth.
Having now described our Invention of "Improved Machinery for
Sharpening Saws," and having explained the manner of carrying the same
into effect, we claim as the Invention secured to us by Letters Patent
as aforesaid, mounting circular saws on a central spindle and communicating
an intermittent motion thereto for the purpose of bringing the teeth of the
saw in succession under the action of a reciprocating or other file or cutter,
whereby they may be sharpened, as herein set forth.
In witness whereof, we, the said John Parry and Richard Morris,
have hereunto set our hands and seals, the First day of February, in
year of our Lord One thousand eight hundred and sixty-seven.
the
Witness,
WILLIAM MAUGHAM, M. D.,
Carnarvon.
JOHN PARRY.
(L.S.)
RICHARD MORRIS. (L.S.)