IMPROVEMENTS IN APPARATUS FOR SHARPENING SAWS
Year: 1858

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention
of "IMPROVEMENTS IN APPARATUS FOR SHARPENING SAWS."-A com-
munication.
Sealed the 1st November 1858, and dated the 7th May 1858.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 7th May
1858.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR SHARPENING SAWS," to be as.
follows:-
This Invention relates to a machine for sharpening all kinds of saws by
means of a small grindstone or surface which enters between the teeth of the
saw, which small revolving grinding surface receives rapid rotary motion.
This machine is represented in the annexed Drawings, in which Fig. 1
represents a side elevation of the machine arranged for sharpening ordinary
saws; Fig. 2, plan, in which the carriage or support of the saw is removed;
Fig. 3, front elevation of the same; and Fig. 4, plan of the carriage or support
of the saw; Fig. 5, front extremity of the machine, furnished with the peculiar
apparatus for sharpening circular saws; Fig. 6, front elevation of the machine,
also furnished with the apparatus for sharpening circular saws (in this
Figure the part carrying the grinding or sharpening surface is removed from

page_text: the machine); and Fig. 7, plan of the apparatus for sharpening circular
saws. In all these Figures similar letters of reference indicate like parts
where they recur.
a, front frame of the machine; b, back frame of the machine; c, c, stays
for attaching frames a and b firmly together; d, table or bench bolted
in front to frame a, and behind to frame b; e, e, uprights fixed to plate
d by means of bolts; f, bracket bearing placed at the upper part of uprights
e, e; it is extended towards the front part of the machine; 9, 9, swinging
frame moving on two points fixed to a moveable ring g', capable of turning
on a curved guide fixed to uprights e, e. The fixing of the ring and guide is
effected by means of bolts, as seen in Fig. 6. The ring g' carries two small
points for marking on a dial the course traversed. h, horizontal shaft mounted
on centres at the front extremity of frame g, g; i, thin grindstone or substance of
emery fixed on shaft h; this grinding surface receives motion at the rate of, say,
five hundred or six hundred revolutions per minute; its periphery, which is
shaped like the teeth of the saw, is caused to enter between each of the con-
secutive teeth, and thereby effects the sharpening; j, j, grooved pullies, also
keyed on shaft h; they communicate rotary motion to i; k, shaft turning in two
bearings fixed to the upper part of e; 1, strap pulley keyed on shaft k, from which
it receives motion from any motor; m, grooved pulley keyed on shaft k, from
which it receives motion, and transmits it to the shaft of i by means of a band
passing over one of the pullies j; n, parts for extending and tightening the band;
they turn in bearings united to uprights e; o, counterweight, the lever of
which oscillates on the extremity of support f; this counterweight is intended
to maintain the equilibrium of the swinging frame g, which is placed at any
height desired by means of a chain; p, p, handles fixed to g, g, for the purpose
of raising or lowering the grinding surface, or to move it round;.q, table fixed
to the front frame a by means of two brackets; r, stationary part of the slide;
it is supported by table q, on which it can rotate horizontally; s, body of the
sliding carriage; it slides horizontally on the plater like an ordinary slide,
and is surmounted by wooden clamps s', between which the saw to be
sharpened is pinched; it can move round horizontally so as to be inclined at
a certain angle on the one side or the other; t, small toothed chain wheel in
the interior of r; it is worked by hand by means of a crank t¹; u, chain fixed
at its two extremities to the two extremities of the sliding carriage s; its links
gear into the toothed wheel t, so that when this latter revolves it causes the
chain to move horizontally either to the right or left, and consequently the
sliding carriage also to which it is fixed, as also the saw supported by this
carriage; this movement of the carriage, and consequently of the saw, serves

page_text: to conduct each tooth successively before the sharpening grinding surface or
instrument.
The machine being mounted as indicated in the Drawings, its action will
be readily understood. In order to sharpen the saw, the workman takes hold
of the handles p, p, of swing frame g, and lowers it until the rotatory grinding
stone or surface acts sufficiently on the teeth of the saw, and adjusts swing
frame g to the height desired by means of the chain attaching it to the
counterweight o. One side of the teeth being inclined, the sharpening stone
or surface is inclined parallel therewith; the different inclinations which the
frame and grinding surface can assume are indicated by numerals 1, 2, 3, 4,
5, and 6, on each side of uprights e, e, and in opposite directions. The
grinding surface is allowed to act on the tooth until it is quite sharpened,
after which the frame g is released and carried up by the counterweight, thus
raising the grinding surface; the sliding carriage is then actuated by turning
crank until the third tooth is presented to the action of the grinding
surface, when it is again lowered, and so on. Thus all odd numbers of teeth,
or those set on one side, are sharpened, after which, by moving round the saw
in its clamps, all the even numbers of teeth, or those sct in the opposite
direction, can be sharpened by the same means.
When it is desired to render this machine applicable to the sharpening of
circular saws, the fixed carriage is removed, as well as its bearings, and
replaced by a special carriage, represented at Figs. 5, 6, and 7, seen in front,
side, and plan views. v, bearing, bolted to the frame a; x, upright, the
lower extremity of which rests on bearing v, on which it is bolted so as not to
turn otherwise than horizontally; at its upper extremity a small plate is
bolted, which rests on the bench; this horizontal circular motion is instead of
the circular motion of the carriages, and is intended to effect the same
purpose. The angles described by the upright are indicated on plate a by
the figs. 1, 2, 3, 4, 5, and 6, placed on each side and in the opposite direction,
because it is necessary to go twice over circular saws also. y, slot in the upper
frame; z, cross beam, furnished with a fillet or tongue which slides in the
groove, and always maintains the cross beam in a horizontal position therein;
a', groove made nearly throughout the length of cross bean z; the shaft of
the circular saw is placed in this groove. The cross beam may be raised in
groove y a height depending on the diameter of the saw to be sharpened.
The action of the machine is the same for circular saws as for straight ones,
but after having raised the saw and lowered the grinding surface, it only
remains to turn the shaft of the saw by hand each time a tooth has been
sharpened.

page_text: A single workman is sufficient for working this machine, which effects
great economy in the materials and the time, and also produces work much
superior to hand work as regards regularity.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 5th
November 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Civil Engineer
and Patent Agent, send greeting.
:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of May, in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Clark, Her special licence that I, the said William Clark, my executors,
administrators, and assigns, or such others as I, the said William Clark, 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
sexpressed, 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 SHARPENING SAWS;" (a
communication,) upon the condition (amongst others) that I, the said William
Clark, 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 Clark, 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, reference being had to the Sheet of Drawings hereunto annexed;
and to the letters and figures marked thereon (that is to say):-
This Invention relates to a machine for sharpening all kinds of saws by
means of a small grindstone or surface which enters between the teeth of the
saw, which small revolving grinding surface receives rotary motion.
.
This machine is represented in the annexed Drawings, in which Fig.

page_text: represents a side elevation of the machine arranged for sharpening ordinary
saws; Fig. 2, plan of the same, in which the carriage or support of the saw
is removed; Fig. 3, front elevation of the same; and Fig. 4, plan of the
carriage or support of the saw; Fig. 5, front extremity of the machine, fur-
nished with a peculiar apparatus for sharpening circular saws, & Fig. 6, front
elevation of the machine, also furnished with the apparatus for sharpening
circular saws (in this Figure the part carrying the grinding or sharpening
surface is removed from the machine); and Fig. 7, plan of the apparatus for
sharpening circular saws. In all these Figures similar letters of reference
indicate like parts where they recur.
a, front frame of the machine, fixed to the ground by means of bolts; b,
back frame of the machine, also fixed to the ground by bolts; c, c, stays for
attaching frames a and b firmly together; d, table or bench, bolted in front to
frame a, and behind to frame b; e, e, uprights fixed to plate d by means
of bolts; f, bracket bearing placed at the upper part of uprights e, e, it is
extended towards the front part of the machine; 9, 9, swinging frame moving
on two points fixed to a movable ring g', capable of turning on a circular guide
fixed to uprights e, e. The fixing of the ring and guide is effected by means
of bolts, as seen in Fig. 6. The ring g¹ carries two small pointers for marking
on a dial the course traversed. h, horizontal shaft mounted on centres at the
front extremity of frame g, g; i, thin grindstone or substance of emery fixed
on shaft h; this grinding surface receives motion at the rate of, say, five
hundred or six hundred revolutions per minute, its periphery, which is shaped
like the teeth of a saw, is caused to enter between each of the consecutive
teeth, and thereby effects the sharpening; j, j, grooved pullies, also keyed on
shaft h; they communicate rotary motion to the grindstone i; k, shaft turning
on two bearings fixed to the upper part of e; l, strap pulley keyed on shaft k;
it receives motion from any motor; m, grooved pulley keyed on shaft k, from
which it receives motion, and transmits it to the shaft of grindstone i by
means of a band passing over one of the pullies j; n, parts for extending and
tightening the band; they turn on bearings united to uprights c; o, counter-
weight, the lever of which oscillates on the extremity of support f; this
counterweight is intended to maintain the equilibrium of the swinging frame g,
which is placed at any height desired by means of a chain; p, p, handles
fixed to g, g, for the purpose of raising or lowering the grinding surface, or to
move it round; q, table fixed to the front frame a by means of two brackets;
r, stationary part of the slide; it is supported by table q, on which it can
rotate horizontally; s, body of the sliding carriage; it slides horizontally on
the plater like an ordinary slide, and is surmounted by wooden clamps s¹,

page_text: between which the saw to be sharpened is pinched; it can move round
horizontally, so as to be inclined at a certain angle to the one side or to the
other; t, small toothed chain wheel in the interior of fixed carriage r; it is
worked by hand by means of a crank t¹; u, chain fixed at its two extremities
to the two extremities of the sliding carriage s; its links gear into the toothed
wheel t, so that when this latter revolves it causes the chain to move hori-
zontally either to the right or left, and consequently the sliding carriage s also,
to which it is fixed, as also the saw supported by this carriage. This
movement of the carriage, and consequently of the saw, serves to conduct
each tooth successively before the sharpening grinding instrument or surface.
The machine being mounted as indicated in the Drawings, its action will
be readily understood. Supposing, 1st, that pulley receives rotary motion
from any motor, this motion will be transmitted by means of the band to
shaft k, which supports the grindstone; 2ndly, that the saw to be sharpened
has been pinched between the clamps s¹, s, of the vice or carriage s. In order
to sharpen the saw the workman takes. hold of the handle p, p, of swing
frame g, and lowers it until the rotatory grinding surface acts sufficiently on
the tooth of the saw, and then adjusts the swing frame g at this desired height
by means of the chain attaching it to the counterweight o. On one side of
the teeth being inclined the sharpening stone or surface is inclined parallel,
which movement is easily effected, the swing frame g being, as before stated,
fixed on a circular guide which can traverse nearly all the degrees in the
circumference, hence the swing frame, and consequently the grindstone, can be
suitably inclined.. The different inclinations which the frame and grinding
surface can assume are indicated by numerals 1, 2, 3, 4, 5, and 6, placed on
each side of uprights e, e, and in opposite directions. The grinding surface
is allowed to act on the tooth until it is quite sharpened, after which the frame
9 is released and carried up by the counterweight, thus raising the grinding
surface; the sliding carriage is then actuated by turning crank t' until the
third tooth is presented to the action of the grinding surface, when it is again
lowered, and so on. Thus all odd numbers of teeth, or those set on one side,
are sharpened, after which, by moving round the saw in its clamps, all the
even numbers of teeth, or those set in the opposite direction, can be sharpened
by the same means, and thus the largest saws may be sharpened in a few
minutes.
When it is desired to render this machine applicable to the sharpening of
circular saws, the fixed carriage r is removed as well as its bearing, and a
special carriage substituted for it, represented at Figs. 5, 6, and 7 in front,
side, and plan views. v, bearing, bolted to the front frame a; a, upright, the

page_text: lower extremity of which rests on bearing v, on which it is bolted so as not to
turn otherwise than horizontally; at its upper extremity a small plate is bolted,
which rests on the bench. This horizontal circular motion is instead of the
circular motion of the carriage s, and is intended to effect the same purpose.
The angles described by the upright are indicated on plate a by the figures
1, 2, 3, 4, 5, and 6, placed on each side and in opposite direction, because
it is necessary to go twice over circular saws also. y, slot in the upper frame x;
z, cross beam, furnished with a fillet or tongue which slides in the groove and
always maintains the cross beam in a horizontal position therein; a', groove
made nearly throughout the length of cross beam z; the shaft of the circular
saw is placed in this groove. The cross beam may be raised in groove y a
height depending on the diameter of the saw to be sharpened.
The action of the machine is the same for circular saws as for straight ones,
but after having raised the saw and lowered the grinding surface, it only
remains to turn the shaft of the saw by hand each time a tooth has been
sharpened.
The action of this machine is very simple, and produces the desired effect in
a perfect manner. A single workman is sufficient for working this machine,
which effects great economy in the expence of files usually employed, also in
the time required; it also produces work much superior to hand work as
regards regularity.
The machine may receive motion from a crank and from a series of pullies
furnishing motion at a rate of from four hundred to six hundred revolutions
per minute; the apparatus may also be rendered movable by mounting it
on wheels.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, the Fifth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witness,
W. G. E. SWINNOCK,
53, Chancery Lane.
W. CLARK. (L.S.)