IMPROVEMENTS IN SAWS AND SAW TEETH AND IN MACHINERY FOR MANUFACTURING THE SAME
Year: 1869

page_text: LETTERS PATENT to Samuel Greene Arnold, of Providence, Rhode
Island, United States of America, now of No. 8, Southampton
Buildings, London, for the Invention of "IMPROVEMENTS IN SAWS
AND SAW TEETH AND IN MACHINERY FOR MANUFACTURING THE SAME,"
Sealed the 11th January 1870, and dated the 23rd November 1869.
PROVISIONAL SPECIFICATION left by the said Samuel Greene Arnold
at the Office of the Commissioners of Patents, with his Petition,
on the 23rd November 1869.
I, SAMUEL GREENE ARNOLD, of Providence, Rhode Island, United
States of America, now of No. 8, Southampton Buildings, London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SAWS AND SAW TEETH AND IN MACHINERY FOR MANUFACTURING THE SAME," to
be as follows:-
This Invention relates to further improvements in the saws and saw
teeth described in the Specification of an Invention for which Letters
Patent were granted to William Robert Lake, bearing date the 15th
day of June, in the year of our Lord 1867, No. 1756.

page_text: The first part of the said Invention relates to removable saw teeth,
and is designed to render them economical of manufacture and capable
of working without setting and to give them the greatest possible
efficiency in cutting with the least expenditure of power. These teeth
being adapted to various methods of insertion, such as are specified in
the said former Specification and others, therefore need no description
with regard to form of shank or manner of insertion into the saw plate.
These teeth may be manufactured from plain sheet or bar steel of
thickness equal to or less than that of the saw plate by cutting them out
with dies in the proper form, and then by means of swages turning over
the top of the tooth while hot upon one or both sides, so as to form
flanges of the necessary width for cutting the saw kerf. The flange may
be produced by rolling or forging steel upon steel bars or by milling with
milling machines. When the flange upon the tooth is formed upon
one side only the teeth are inserted alternately with the flange reversed,
and are equivalent to the common saw when bent or set right and left
alternately, while the double-flanged tooth answers to the square front
swaged tooth which is well known by those familiar with the use of
circular saws. The flanges upon the teeth are formed to recedo laterally
on each side towards the rear to give the teeth sufficient freedom in the
kerf to work without heating. The teeth have a recess under the flange,
which recess not only gives greater clearance to the tooth in working
but facilitates the construction of the tooth, inasmuch as the metal
forced out of these recesses while hot helps to form the flange upon the
top with less expenditure of material and labor in forming this flango
than would otherwise be required.
The said Invention relates, secondly, to forming the tops of removable
saw teeth in such a manner that they will not require filing or grinding
at the back when the teeth are worn but need only be dressed or ground
on the front portion. The ordinary saw teeth are made in such a
manner that if filed or ground only in front these points will soon be
reduced to the same diameter as the rear part of the top of the tooth,
so that the said rear part will come in contact with the wood at the
same time as the points of the teeth, and thus prevent the cutting of
To prevent this difficulty the rear portion of the tooth is made
in two or more straight lines or is curved to suit the feed line in action,
50 that the tooth retains its greatest possible strenth while there is
always sufficient clearance for the rear of the tooth to prevent all friction
the saw.

page_text: at that part until the tooth is worn out by being ground only on the
front, the rear part of the tooth converging towards the centre of the
saw more or less in proportion to the rate of feed and number of teeth
used in that particular class of saws for which the teeth are made.
The said Invention relates, thirdly, to constructing a planing tooth for
a saw by swaging or otherwise forcing the metal out at one side of the
cutting portion in such a manner as to cause it to cut on one side only.
The outer corners are rounded so that it works like a gouge, while the
flattened portion following being sharpened cuts or planes the surface
level while it is gauged upon the opposite side by the projections formed
in swaging. By using two of these teeth both sides of the. kerf are
effectually planed and the shaving taken out thereby clears the saw plate
as well as when the saw teeth have the ordinary setting, so that the
Kerf is no wider than that of an ordinary rough cutting saw.
The said Invention relates, fourthly, to making a cross cutting tooth
in the following manner, namely, the shank may be formed as before
described, but the top of the tooth is made with a V-shaped groove in it
and is inclined backward at such an angle as to avoid friction. These
teeth require only to be ground in front with a V-shaped grinding
wheel, or if tempered like a common saw may be filed on both points
at once with an ordinary three-sided file. These teeth should also te
used with flat pointed teeth of sufficient number, which following and
being set a little nearer the centre of the saw than the others pare out
the kerf as the same is grooved or cut down on each side by the said
cross cutting teeth instead of leaving it to be wedged or split off as
by an ordinary saw, thus working with less expenditure of power, and
being more easy to keep in order than the ordinary cross cutting
teeth.
The said Invention relates, fifthly, to constructing the lower part or
shank of the tooth with two holes for the purpose of holding it while
finishing the edges and grooving it upon the sides: Also to so
forming the bottom of the shank that it terminates in two angular
lincs each at an angle of about forty-five degrees to the parallel sides
and at a right angle to each other, the point or apex being intersected
by the centre line of the shank. To avoid difficulty, however, in manu-
facturing the teeth the extreme point is cut off, so that the cutters that
form the recess in the plate for the reception of the shank will not
require an acute point. The bottom of the tooth is made in this form
ດ

page_text: in order that the cutters which form the V-shaped grooves on the edge
of the plate may not come in contact with the bottom of the incision:
while they mill the sides of the same.
The said Invention relates, sixthly, to fastening detatchable saw teeth
to prevent their radial displacement. This part of my Invention may
be applied to saws of any thickness or kind and will be found perfectly
practical in saws of a very thin gauge. The teeth may be inserted and
secured in the plate laterally by the means described in the said former.
Specification or otherwise. According to the present Invention they
are locked radially by a sliding bolt, the end of which is fitted to enter
a corresponding recess in the tooth in the. part thereof adjacent. to that
part of the plate in which the said bolt is inserted. It may, however,
be located either in the saw plate or tooth. The recess has the sides
chamfered, and the bolt is made with corresponding flanges to fit the
chamfered sides, and is thereby kept from lateral displacement in the
same manner as the teeth. It is also kept from moving longitudinally
by being slightly curved or bent in the central part; so that it will when
tempered form a spring which is straightened when forced into the
chamfered recess, the friction produced by this curvature preventing its
moving longitudinally until it is forced in either direction by a key
provided for that purpose. To give more strength and bearing surface
to the locking end of the bolt and at the same to give it more
elasticity when curved the centre of the grooves in the edges of the
bolt are not cut in a perfect V-shape but are left flat in the bottom of
the channel. In order that the end of the bolt may enter readily into
the recess in the tooth in locking the same the flanges are cut off to
the bottom of the grooves, thus leaving the locking portion of the
bolt with four flat sides the top corners of which should be slightly
rounded to cause it to enter the recess without cutting a burr in the
same. The said bolt may also be secured longitudinally without being
curved if desired by forming the flanges in such a manner that when
tempered they will bear upon the sides of the recess and prevent the
moving of the bolt longitudinally. In nearly all saws using inserted
teeth it is preferable to insert the said bolt in the plate of the saw instead
of in the tooth, as one set of bolts will then serve for any number of
teeth. The key for locking, unlocking, and changing the teeth should
be made flat at the end and should be taper therefrom to about twice
the length of the bolt to be operated, one side being parallel with the

page_text: axis of the key. Its thickness at the thickest part should be just equal
to the distance which the bolt is required to move longitudinally. This
width should continue for about one-fourth of an inch or twice the
thickness of the saw plate, and should terminate with a square shoulder
to stop the key in the plate when the bolt has been moved the full
distance. The operator is thus enabled to slide the bolt and remove
the teeth very rapidly and without any special care or any danger of
displacing or over straining either of the parts. To provide for the
ready entrance of the key the recesses both in the plate and key are made
of sufficient length to leave an opening for the point of the key when
the bolt is forced as far as it will go in either direction, so that in
either locking or unlocking the bolt there will be an opening at the
required end of the bolt to receive the key. The holes above mentioned
in the teeth serve for the reception of the key by means of which they
are removed from the plate and allowed to remain upon the key until
they are all removed from the plate. For this purpose the stem or rod
of the said key from the shoulder backward should be made of round
steel, rather less in diameter than the size of the holes in the tooth,
and should be of sufficient length between the said shoulder and the
handle to allow the teeth removed from the plate to remain upon the
said stem or rod without inconvenience to the operator. In replacing
and locking the teeth the full number required should first be placed
upon the key, and the process of removing the teeth being reversed the
teeth are readily inserted, locked, and ready for use.
The said Invention relates, seventhly, to the particular position for the
insertion of the shanks of the teeth, and also to the proper relation of
the bolt to the tooth. The shank of the tooth should be inserted at an
angle of about forty-five degrees to a radial line in the saw plate, and
they should not vary from this more than about five degrees, otherwise
the desired result will not be accomplished. By this peculiar angular
insertion the tooth stands in such a position that when its point comes
in contact with the wood the force exerted has a tendency to drive the
tooth back into its socket, as the line of insertion approximates towards
the line of action in cutting the lumber, but without weakening the saw
plate, as would be the case if the angle were much greater. The sliding
bolt for locking the tooth must also be inserted at an angle of about
sixty degrees to the line of the shank of the tooth in order to give it the
greatest efficiency. By giving it this angle in relation to the tooth the

page_text: bolt has a drawing tendency, by which it forces the tooth back into the
bottom of its recess when the bolt is forced into the tooth by the key;
this angle in relation to the tooth will also locate the bolt at an angle of
about twenty degrees to a radial line of the saw plate, in which position
the incision made in the saw plate to receive the bolt will not practically
diminish the strength of the plate.
The said Invention relates, eighthly, to an adjustable vise for holding
the teeth at any desired angle while they are being milled or finished,
which vise is constructed as follows:-The bed of the vise is made round
with a flange, by which to clamp it to the machine whereon it is used.
In the centre of the vise there is a column, which may be of any desired
height to suit the machine; this column is turned upon the outside and
fitted with a turned ring, the bottom of which being on a plane with its
axis fits down to and rests upon a portion of the flange. The top of the
vise may be of the usual construction, except that it is provided with
steel jaws V shaped on their upper portion in order to hold the teeth.
Under the ordinary vise and connected thereto is another cylindrical
portion, which is turned to the same diameter as the ring above
mentioned; it is planed to an angle or incline in relation to the top
surface of the vise, and the top portion of the said ring is also planed to
the same angle, so that being placed one upon the other by turning the
ring upon the base the top of the vise is adjusted to any angle desired,
the edges of the two rings are graduated so that any point or angle desired
may be readily determined. If required the base may be unclamped and
turned around or adjusted laterally to suit the cutters of the machine, it
being marked or graduated on the flange of the base also to show upon
the machine its proper location for any desired work. The top portion
of the vise is secured to the base by a bolt and socket joint between the
two parts in such a manner as to permit of its adjustment to any desired
position, and it is secured by a nut or key in the ordinary manner.
The said Invention relates, ninthly, to the mode of manufacturing
these removable saw teeth. The teeth for common saws are cut by
dics of the desired form in an ordinary punching machine from bar or
sheet steel rolled to the proper guage. If the tooth is to be made with
the double flange it is then heated to a working heat and placed in a
clamp or vice having steel jaws, with a recess cut in them of the proper
shape for the flange, which must be at the top of the vise. The tooth
being located by suitable stops is thus clamped and hammered down

page_text: while hot, thus forming a double flange of a shape corresponding with.
that of the die. If a single flango only is desired the tooth is placed in
dies, which hold it horizontally, and the two dies being formed of tho
proper shape the steel is turned over or moulded without any upsetting
into the shape desired, and may be thus worked at a very low heat.
This mode of molding and swaging teeth is applicable to the detachable
teeth of any and all forms which may require it, and is especially
adapted to the production of the S planing teeth, also the cutting and
planing teeth described in the former Specification herein-before referred
to. After the teeth are forged they are finished as follows:-They are
placed in a gig which has holes corresponding to those to be formed
in the teeth, and which is so formed as to locate them accurately in
relation to each other and the working points of the tooth. The tooth.
is then clamped to a block upon the table of an ordinary edging
machine, being located and held by the holes mentioned. The machine
is also provided with a female former, whose periphery should be of the
shape of the tooth desired. Then by a suitable cutter and male former
to corresponding therewith the edge of the tooth is trimmed to the form
desired in the manner well known to those familiar with the use of
edging machines. The grooves in the edge or sides of the teeth are also
cut by the same machine in a similar manner with a V shaped cutter.
The tooth is then placed in the adjustable graduated vise herein-before
described, and is there set to the proper angle and finished on the
cutting parts with suitable milling cutters. The teeth are then clamped
upon the sliding table of a small machine at an angle of about sixty
degrees to its line of motion, and are moved up to a small rotating
cutter of suitable thickness to cut the slot for the end of the bolt to
enter, and the depth of the slot being regulated by a stop. Then after
removing any burr which may remain thereon the tooth may be
hardened and ground, and is then ready for use.
The said Inventions relates, tenthly, to the mode of making the incisions
in the saw plate for the tooth, and forming the outer edge of the plate,
also to cutting the slot, the insertion of the bolt. The saw plate is
supported centrally upon a stud in a punching machine of suitable
capacity, which stud holds the plate at a proper angle in relation to
the plunger and die. Upon this stud also is attached a moveable index
arm with a clamp to secure it to the saw plate; the machine is also
provided with another stationary clamp to secure the saw. The dies and

page_text: plungers are made of the form of the incision desired, and form both the
place for the tooth and the portion between the teeth with one plunger.
The slot for the bolt is also cut at the same time by a flat plunger
secured in a clamped socket immediately adjacent to the larger plunger.
The larger plunger must be made of a shcaring form, and must be
arranged to commence cutting first at the bottom of the tooth, cutting
through the part where the bolt is to be inserted before the small plunger
commences its work. This plunger is grooved into the large plunger to
strengthen it vertically, and is made to cut with a shearing action, so
that its work will be effectively accomplished, the incisions for the tooth
and bolt and the edge of the plate being cut by one revolution of the
punch. When the first incision is made the saw being secured by the
stationary clamp an index, arm which is graduated to any number of
teeth desired is set and clamped upon the number of teeth desired for
the saw. The stationary clamp is released and the arm is moved up to
it, it is then again secured and the incision is out. The moveable clamp
is then released and set as before. The process is thus continued until
the recesses are cut in the saw plate for the full number of teeth; the
saw should then be hardened, ground, and straightened. It is then
clamped upon a sliding table with an adjustable gaugo pin, which is
thrown up through the table by a lever to locate the slots properly; when
the slot is located the saw is olaraped in the proper position and the
guage withdrawn by a lever. The table is then moved up to a revolving
cutter having a taper point of the proper angle to form the chamfers for
the flanges of the bolt, which cutter being adjusted to the proper height
it cuts the chamfer upon both sides of the slot by once moving up to and
passing the cutter along the slot. The saw is turned over and the other
side is treated in the same manner for each bolt, and then the saw after
trimming off the burs is ready for the bolts. When the latter are put in
aid forced back to their unlocked position the saw is ready for the
insertion machine. The bolts may be made from bar or sheet steel rolled
to the proper gauge, and need no side finishing. Being cut to the proper
length and width they are clamped in a small vise upon a sliding table,
and passed under a revolving cutter having the teeth of the shape
desired for the groove.
After the first side is cut the bolt is turned
over upon a block which fits the groove and raises it to the proper
height to make the groove upon the opposite side, which being done
the bolt is set vertically in the end of the vice, which has jaws adapted
to the grooves; the said bolt is then passed between twor evolving cutters,

page_text: which are bevelled to an angle of about sixty degrees, and the flanges are
thus cut from the part desired to enter the tooth, and the end of the bolt
is gauged to its proper thickness. The burrs are then taken off and the
bolt is curved by means of a small dio and plunger or other device, and
bent to its proper form, and when tempered is ready for use.
The said Invention relates finally to a machine for inserting the.
teeth into the plate of the saw, which machine is constructed sub-
stantially in the following manner:-A heavy bed piece with a slot
in the centre to receive the saw and with two heavy sido standards con-
nected at the top by a strong arch piece are supported by suitable legs;
and provided beneath with an adjustable stud and stand to support the
saw in the desired position while it is allowed to revolve upon this stud.
The bed piece is provided with strong supports upon each of the outer
front corners to secure wedges which clamp the vise. These wedges are
formed with an opening to allow a cross head forming part of the machine
to descend to cut the full length of the tooth. These wedges are planed
on the outside to fit the planed surfaces of the side stands and corner
supports above mentioned, and are planed on the inside to an angle
to match the inside clamps, which are of similar construction, with
the angles reversed and are secured at the rear top corner by a heavy
bolt running through them and the side stands, binding them together
and preventing longitudinal movement of the vise clamps, while they
may be moved laterally upon the bolt to make room for the saw, which
when inserted is clamped by the wedges above mentioned, which wedges
are combined with a strong semicircular connection at their smaller ends
and are moved by a screw and hand wheel located centrally in the. rear,
by which means the vise clamps are closed upon the saw with great
force when the wedges are drawn back by the screw and wheel: The
side standards are provided with ways, which are planed to receive the
cross head which slides vertically therein, and is made in a compact form
to hold the independent arbors, cach provided with a pulley driven by
a counter pulley upon a swinging shaft above, which it is connected to
and moves with the cross head by means of two rods attached to the
top corners of the cross head. Each arbor upon its inner end is fitted
for a cutter with threads right and left handed, and is furnished with
cutters independent of each other, which when brought together in
working cut a tongue of a V form. These cutters must be made of
suitable diameter to cut both sides of the incision at the same time..

page_text: The inner end of the arbor is also made with a collar, and provided
with a wedge-shaped washer, which lies against the collar with a flat
bearing, its taper side lying in contact with a taper fork planed to
the same angle but reversed in position. This fork slides against the
end of the box which holds the arbor. This fork being driven down
from above by a screw moves the arbor inward to the saw plate, while
a lever drawn up by the screw the arbor is moved outward from the
saw by the means of a spring having a forked end bearing against
the inner side of the hub of the driving pully fixed on the arbor.
Thus each cutter is made independently adjustable. The screw which
moves the wedge has a graduated dial with a hand and small wheel
at the top of the cross head to show the distance that the arbor is
moved to the thousandth part of an inch, thus by moving the hand by
the small wheel the most accurate adjustment is made in a moment
without the least difficulty, thereby locating the cutters perfectly central
for fitting the teeth. To allow the ready removal and replacing of the
cutters the forked wedges are made to disconnect and turn out from
the screw, and may then be withdrawn from the machine, and ample
room is afforded to change the cutters. In a good saw it is very im-
portant that the bottoms of the teeth should all bear the same relation
to the center of the saw. To provide for this the cross head is furnished
with a round sliding bar, which moves through boxes directly above
the arbors and parallel with the same. This bar is supplied with an
apron attached. thereto, and secured permanently; the said apron is also
provided at the lower part with a tempered steel broach made of the
proper form and with teeth to finish the incision for the base of the
tooth. The sides of this broach are ground perfectly accurate, being
each the same distance from the center of the beveled teeth, and in
order that the broach may always cut with the same relation to the
center of the saw the sliding clamps are fitted next to the saw with
steel plates, which are adjusted by set screws to their proper position
and are cut through and ground to fit the broach. Thus these plates
being set centrally with the cutters of the machine the broach is lowered
into the plates and is moved through the said plates, cutting out from
the bottom of the incisions made for the teeth more or less as it is re-
gulated by stops on the cross head provided to stop it at any desired
altitude. The broach is moved by means of a screw running into the
broach bar, and turned by a hand wheel, both of which are attached
to the cross head by means of a stand secured to the top of the same.

page_text: The apron and broach, which must necessarily work below the arbors
in cutting the base for the tooth, is arranged to turn up and fasten with
a spring catch, while the cutters descend to finish the sides. To facilitate
the operation of these parts the feed screw which is turned by a hand
wheel and attached to the top of the cross head runs through a clamp
nut or vise which is attached to the top of the arch, and is made with
a sliding key, which moving downward between the limbs of the vise
opposite the screw closes the vise so that the cross head moves only by
turning the screw. By moving the key up the vise is opened by a spring
and the cross head is allowed to move at pleasure. The swing above
the machine which is connected therewith as herein-before mentioned,
has a weight attached thereto sufficient to balance both the swing and
the cross head with its appurtenances and it is thus easily moved upward
or downward in working the machine.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Greene Arnold in the Great Seal Patent
Office on the 21st May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
GREENE ARNOLD, of Providence, Rhode Island, United States of
America, now of No. 8, Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of November, in
the year of our Lord One thousand eight hundred and sixty-nine, in
the thirty-third year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Samuel Greene Arnold, Her
special licence that I, the said Samuel Greene Arnold, my executors,
administrators, and assigns, or such others as I, the said Samuel
Greene Arnold, 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 In-
vention for "IMPROVEMENTS IN SAWS AND SAW TEETH AND IN MACHINERY,
FOR MANUFACTURING THE SAME," upon the condition (amongst others) that

page_text: "
I, the said Samuel Greene Arnold, my exccutors or administrators
by an instrument in writing under my, or their, or one of their hands
and scals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed
and canso the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of tho said
Letters Patent.
NOW KNOW YE, that I, the said Samuel Greene Arnold, 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, reference being had to the accompanying
Drawings, forming part of this Specification :-
This Invention relates to further improvements in the saws and saw teeth
described in the Specification of an Invention for which Letters Patent
were granted to William Robert Lake, bearing date the Fifteenth day of
June, in the year of our Lord One thousand eight hundred and sixty-
seven, No. 1756.
The first part of the said Invention relates to so constructing re-
movable saw teeth as to render them economical of manufacture and
capable of working without setting, while giving them the greatest
possible efficiency in cutting with the least expenditure of power. These
teeth are adapted to various methods of insertion, such as that described
in the said former Specifications and others; no description therefore is
nceded with regard to the form or construction of shank, or the con-
struction of the saw plate for allowing the insertion of the teeth into
the said plate.
I will first describe the teeth illustrated in Figures 1, 2, 3, 4, 5, 6, 7,
and 8, which are side and edge views thereof. The said teeth may be
manufactured from plain sheet or bar steel of a thickness equal to or
less than that of the saw plate A by cutting them out with dies of the
proper form, and then by means of swages turning over or flanging
the top of the tooth a while hot upon one or both sides so as to form
flanges a¹ of the necessary width for cutting the saw kerf. These flanges
may be produced by rolling or forging steel bars or by means of milling
machines. When the flange upon the tooth is formed upon one side
only, as in the tooth shewn in Figures 1 and 2, the teeth are so inserted
into the saw plate that the flange of every alternate tooth around the

page_text: saw is reversed; these teeth are then equivalent to the common saw
teeth, which are bent or set right and left alternately. The double
flanged tooth shewn in Figures 3 and 4 serves instead of the square
front swaged tooth, which is well known by those familiar with the use
of circular saws. The flanges upon the teeth are formed to recede, or
taper inward laterally on each side towards the rear to give the teeth
sufficient freedom in the kerf to work without heating. The teeth have
a recess a under the flange a', which recess not only gives greater
clearance to the tooth in working, but facilitates the construction of the
tooth, inasmuch as the metal forced out of these recesses while hot helps
to form the flange a' with less expenditure of material and labor than
would otherwise be required in forming these flanges.
The said Invention relates, secondly, to forming the tops of removable
saw teeth in such a manner that they will not require filing or grinding
at the back when the said teeth are worn down, but need only be dressed
or ground on the front portion. Ordinary saw teeth are made in such a
manner that if filed or ground only in front their point will soon be
reduced to the same diameter as the rear part of the top of the tooth,
so that the said. rear part will come in contact with the wood at the
same time as the point of the teeth and thus prevent their cutting. To
prevent this difficulty the rear portion from 1 to 2 of my improved tooth
is inclined or curved inward, that is to say, the top or outer edge of the
tooth is made in two or more straight lines or is curved to suit the feed
lino x, x, Figure 14, in action, so that the tooth retains its greatest
possible strength while there is always sufficient clearance for the rear
of the tooth to prevent any friction at that part until the tooth is
completely worn out by the grinding of its front surface. The con-
vergence of the rear part 1, 2, of the tooth towards the centre of the
saw should be more or less in proportion to the rate of feed and number
of teeth used, the number of teeth being determined by the particular
class of saws for which the said teeth are made.
The said Invention relates, thirdly, to constructing a planing tooth for
a saw by swaging or otherwise forcing the metal cut at one side of the
cutting portion, as shewn in Figure 8, in such a manner as to cause it
to cut on one side only; the outer corners 6 of this tooth are rounded,,
so that it acts as a gouge, while the flattened portion 6' following being
sharpened cuts or planes the surface level while it is gouged upon the
opposite side by the projections formed in swaging. By using two of

page_text: these teeth both sides of the kerf are effectually planed and the shaving
taken out thus clears the saw plate as well as if the saw tecth had the
ordinary setting, so that the kerf is no wider than that of an ordinary
rough cutting saw.
The said Invention relates, fourthly, to making a cross-cutting tooth in
the following manner, namely:-The shank may be formed as before
described, but the top of the tooth is made, as shown in Figures 5, 6,
and 7, with a V-shaped groove c in it, and is inclined backward at such
an angle as to avoid friction. These teeth require only to be ground in
front with a V-shaped grinding wheel, or if tempered like a common saw
may be filed on both points at once with an ordinary three-sided file.
These teeth should also be used with a sufficient number of flat-pointed
teeth, which following and being set a little nearer the centre of the
saw than the cross-cutting teeth pare out the curve as the same is
grooved or cut down on each side by the said cross-cutting teeth instead
of leaving it to be wedged or split off as it would be by an ordinary saw.
The saw thus works with less expenditure of power, and its teeth are
more easily kept in order than the ordinary cross-cutting teeth.
The said Invention relates, fifthly, to constructing the lower part or
shank a of the tooth with two holes d for the purpose of holding it
while finishing the edges and grooving it upon the sides; also in so
forming the bottom a of the shank that it terminates in two angular
lines, each at an angle of about forty-five degrees to the parallel sides,
and at a right angle to the other, as shown; to avoid difficulty, however,
in manufacturing these tecth the extreme point is cut off, so that the
cutters that form the recess in the plate A for the reception of the
shank a³ will not require an acute point. The bottom of the tooth is
made in this shape in order that the cutters which form the V-shaped
grooves in the edge of the plate may not come in contact with the
bottom of the incision while they mill the sides of the same.
The said Invention relates, sixthly, to means for fastening detachable
saw teeth in such a manner as to prevent their radial displacement. This
part of my Invention may be applied to saws of any thickness or kind,
and will be found perfectly practicable in saws of a very thin gauge.
The improved teeth herein-before described may be inserted and secured
in the plate A laterally by the means described in the aforesaid former
Specification or otherwise; but by my present Invention I have provided
other means for accomplishing this object, which I have illustrated in

page_text: Figures 9, 10, 11, 12, 13, and 14. For this purpose I insert in the
plate A a sliding bolt e, the end e' of which is fitted to enter a corre-
sponding recess f in the tooth a at the part thereof adjacent to the
groove in the plate in which the said bolt is inserted. The groove in the
plate has the sides chamfered, and the bolt e is made with corresponding
flanges f (see Figure 13) to fit the said chamfered sides, and is thereby
kept from lateral displacement in the same manner as the teeth; it is
also kept from moving longitudinally by being slightly curved or bent,
as shewn in Figure 12, so that when tempered it will form a spring;
when forced into the chamfered recess of the said bolt is straightened, and
the friction produced by its curvature causes it to bind tightly in its
socket, thus preventing its moving longitudinally until it is forced in
either direction by a key h, Figure 15, provided for that purpose. To
give more strength and bearing surface to the locking end of the bolt e,
and at the same time to render it more clastic when curved, the centre
of the grooves in the edges of the said bolt are not cut to a perfect
V shape, but are left flat at the bottom of the channel in order that the
end of the bolt may enter easily into the recess in the tooth in locking
the same. The flanges are cut off at the bottom of the grooves, as shewn
in Figure 14, thus leaving the locking portion of the bolt e with four flat
sides, the top corners of which should be slightly rounded to cause it to
enter the recess without producing a burr in the same. The bolte may
also be secured longitudinally without being curved if desired by forming
the flanges f¹ in such a manner that when tempered they will have
sufficient elasticity to bind upon the sides of the recess fand thus pre-
vent the moving of the bolt longitudinally. In nearly all saws having
inserted teeth it is preferable to insert the locking bolt in the plate of
the saw instead of in the tooth; it may however be inserted in the latter
if desired. The key for locking, unlocking, and changing. the teeth
should be made flat at the end h', and should be taper therefrom to
about twice the length of the bolt e, one side being parallel with the axis
of the said key; its thickness at the thickest part should. be just equal
to the distance which the bolt e is required to move longitudinally; this
width should continue for about twice the thickness of the saw plate A,
and should terminate with a square shoulder h' to stop the key in the
plate when the bolt has been moved its full distance. The operator is
thus enabled to slide the bolt e and remove the teeth a very rapidly and
without any special care or any danger of displacing or overstraining

page_text: either of the parts. To provide for the ready entrance of the key the
recesses both in the plate A and tooth a are made of sufficient length to
leave an opening for the point of the key h when the bolt e is forced as
far as it will go in either direction, so that in either locking or unlocking
the teeth there will be an opening at the required end of the bolt to
receive the said key. The holes.d above mentioned in the teeth serve
for the reception of the key and allow each tooth to be conveniently
removed from the plate and retained upon the key until all of the teeth
are removed from the plate. For this purpose the stem or rod of the.
said key from the shoulder h³ backward should be made of round steel
rather less in diameter than the size of the holes d in the tooth, and
should be of sufficient length between the said shoulder and the handle.
h³ to allow the teeth removed from the plate A to remain upon the said.
stem or rod without inconvenience to the operator. In replacing and
locking the teeth the full number of teeth required should first be placed
upon the key, and the process of removing the teeth being reversed the
teeth are readily inserted, locked, and ready for use.
The said Invention relates, seventhly, to the particular position for
the insertion of tho'shanks of the teeth, and also to the proper relation
of the bolt to the tooth. The shank a³ of the tooth should be inserted at
an angle of about forty-five degrees to a radial line in the saw plate A,
as shown in Figures 9 and 10, and should not vary from this angle more
than about five degrees, otherwise the desired result will not be accom-
plished. By this peculiar angular insertion the tooth stands in such a
position that when its point comes in contact with the wood the force 2
exerted has a tendency to drive the tooth back into its socket as the lino
of insertion approximates towards the line of action in cutting, and
without weakening the saw plate, as would be the case if the angle
were much greater. The sliding bolt e for locking the tooth must also
be inserted at an angle of about sixty degrees to the line of the shank 3
of the tooth, as shewn, in order to give it the greatest efficiency. By..
placing it at this angle in relation to the tooth the bolte has a
drawing tendency, by which it forces the tooth a back into the bottom of
its recess when the said bolt is pushed into the tooth by the key h. By
being placed at this angle in relation to the tooth the bolt e will be at an 3
angle of about twenty degrees to a radial line of the saw plate A, in which
position the incision made in the said saw plate to receive the bolt e will
not practically diminish the strength of the plate.

page_text: The said Invention relates, eighthly, to an adjustable vice, Figure 16,
for holding the teeth a at any desired angle while they are being milled
or finished, which vice is constructed as follows:-The bed i of the vice
is made round, with a flange by which to clamp it to the machine
whercon it is used. In the centre of the said vice there is a column j,
which may be of any desired height to suit the machine. This column
is turned upon the outside and fitted with a turned ring, the bottom of
which being in a plane with its axis fits down and rests upon a portion
of the flange . The top of the vice may be of the usual construction,
except that it is provided with steel jaws bevilled on their upper portion
in order to hold the teeth. Under the vice and connected thereto is
another cylindrical portion k, which is turned to the same diameter as
the ring abovo mentioned. It is planed to an angle or incline in
relation to the top surface of the vice, and the top portion of the ring ♬
is also planed to the same angle. These parts being placed one upon the
other it follows that by turning the ring upon the base the top of the
vice is adjusted to any angle desired. The edge of the ring is gra-
duated so that any point or angle desired may be readily determined.
If required the base may be unclamped and turned around or adjusted
laterally to suit the cutters of the machine, it being also marked or
graduated on the flange to shew upon the machine its proper location
for any desired work. The top portion of the vice is secured to the base
by a bolt and socket joint between the two parts in such a manner as to
permit of its adjustment to any desired position, and it is secured by a
nut or key in the ordinary manner.
The said Invention relates, ninthly, to the mode of manufacturing
these removable saw teeth. The teeth for common saws are cut by dies
of the desired form in an ordinary punching machino from bar or sheet
steel rolled to the proper gauge. If the tooth is to be made with the
double flange it is then heated to a working heat and placed in a clamp
or vice, Figure 17, having steel jaws / with a recess cut in them of the
proper shape for the flange, which must be at the top of the vice. The
tooth being located by suitable stops is clamped and hammered down
while hot, thus forming a double flange of a shape corresponding with
the recess in the jaws. If a single flange only is desired the tooth is
The
placed in dies which hold it horizontally, as shewn in Figure 18.
two dies m being formed of the proper shape the steel is turned over or
1

page_text: moulded (without any upsetting) into the shapo desired, and may be
thus worked at a very low heat. This mode of moulding and swaging"
the teeth is applicable to detachable teeth of any form, and is especially
adapted to the production of the S-formed planing teeth and the cutting
and planing teeth 'described in the former Specification hercin-before
referred to. After the teeth are forged they are finished as follows:-
They are placed in a jig, which has holes corresponding to the holes d
to be formed in the teeth, and which is so formed as to locate these holes
accurately in relation to each other and to the working points of the
tooth. After the holes d have been drilled in the tooth the latter is
clamped to a block upon the table of an ordinary edging machine, being
located and held by the aforesaid holes. The machine is also provided
with a female former whose periphery should be of the desired shape of
the tooth. Then by a suitable cutter and male former corresponding
therewith the edge of the tooth is trimmed to the desired form in a
manner well known to those familiar with the use of edging machines.
The grooves in the edges or sides of the teeth are also cut by the same
machine in a similar manner with a V-shaped cutter. The tooth is then'
placed in the adjustable graduated vice, Figure 16, herein-before
described, and is there set to the proper angle and finished on the
cutting parts with suitable milling cutters. The teeth are then clamped
upon the sliding table of a small machine at an angle of about sixty.
degrees to its line of motion, and are moved up to a small rotating
cutter of suitable thickness to cut the slot or recess for the end of the
bolt to enter, the depth of the slot being regulated by a stop. Then
after removing any burr which may remain therein the tooth may be
hardened and ground and is then ready for use.
The said Invention relates, tenthly, to the mode of making the
Incisions in the saw plate for the tooth, and forming the outer edge of
the plate; also to cutting the slot for the insertion of the bolt. The
saw plate is supported centrally upon a stud q, Figure 19, under a
punching machine of suitable capacity, which stud holds the plate at a
proper angle in relation to a plunger and die, shewn to an enlarged scale
in Figures 20, 21, 22. Upon this stud also is placed a movable index
to secure it to the saw plate A. The machine is
also provided with a stationary clamp to secure the saw. The dies 8
and plungers s' are made of the form of the incision desired, and I prefer
arm
with a clamp

page_text: to form both the place for the tooth and the portion between the teeth
with one plunger. The slot for the bolt e is also cut at the same time
by a flat plungers secured in a clamped socket & immediately adjacent
to the large plunger. The said large plunger should have a shearing.
form, and must be arranged to commence cutting first at the bottom of
the tooth, and to cut through the part where the bolt is. to be inserted
before the small plunger commences; its work. This small plunger is.
grooved into the large plunger a' to strengthen it vertically, and is made
to cut with a shearing action so that its work will be effectively accom-
plished, the incisions for the tooth and bolt and edge of the plate being
cut by one stroke of the punch. When the first incision is made in the
plate and while the saw plate is secured by the stationary clamp the
index arm, which is extended over an arc graduated to suit any
desired number of teeth is set and clamped in the proper position for the.
number of teeth to be placed in the saw. The stationary clamp is then
released from the plate, and the arm which is clamped to the plate A
is moved up to it. The plate is then again, secured and the incision. is
made. The movable clamp is then released and set on the arc as before::
The process is thus continued until the recesses are cut in the said plate
for the full number of teeth. The saw should then be hardened, ground;
and straightened. It is then clamped upon a sliding table u, Figures 23
and 24, with adjustable gauge pins u', which are thrown up through the
table by a lever u² to locate the plate properly. When thus located the
plate is clamped in the proper position, and the gauge u withdrawn by
the lever. The table is then moved up to a revolving cutter ³ having a
taper point of the proper angle to form the chamfers for the flanges of
the bolt e, which cutter being adjusted to the proper height cuts: the
chamfer upon both sides of the slot by once passing the cutter along the
slot. The plate is turned over and the other side is treated in the same
manner for each bolt, and then the saw after having the burrs trimmed
off is ready for the bolts. When the latter are put in and forced back to
their unlocked position the saw is ready for the insertion machine,
Figures 28, 29. The bolts e may be made from bar or sheet steel rolled
to the proper gauge, and need no side finishing. Being cut to the
proper length and width they are clamped in a small vice upon a
sliding table v, Figures 25 and 26, and passed under a revolving cutter o
having teeth of the shape desired for the groove f. After the first
side is cut the bolt e is turned over upon a block o, which fits the

page_text: roove and raises it to the proper height to make the groove upon
the opposite side; this being done the bolt is set vertically, as shewn
in Figure 26, in the end of the vice, which has jaws vs adapted
to the grooves. The said bolt is then passed between two revolving
cutters, Figure 27, which are bevelled to an angle of about sixty
degrees, and the flanges are thus cut from the part desired to enter
the tooth, and the end of the bolt is gauged to its proper thickness.
The burrs are then taken off and the bolt e is curved by means of
a small die and plunger or other device to its proper form, and when
tempered is ready for use.
The said Invention relates, finally, to a machine for inserting the teeth
into the plate of the saw, which machine is illustrated in Figures 28 to
35, Figures 28 and 29 being a front and side elevation of the said
machine, and the remaining Figures shewing detached portions thereof.
A heavy bed piece B is formed with a slot B' in the centre to receive the
saw, and with two sido standards B connected at the top by a strong
arch piece B³. This bed is supported by suitable legs, and provided
beneath with an adjustable stud C and bracket D to support the saw in the
desired position, while it is allowed to revolve upon the said stud. The
bed piece B is provided with strong brackets E upon each of the outer
front corners to hold the wedges F which clamp the vice. Theso wedges
are formed with an opening to allow a cross head G forming part of tho
machine to descend to cut the full length of the tooth; these wedges are
planed on the outside to fit the planed surfaces of the side standard and
corner brackets above mentioned, and are planed on the inside to an
angle corresponding with the inside clamps H, which are of similar
construction, but have the angles reversed, and are secured at the rear
top corner by a bolt, I running through them and binding them together.
By this means I prevent longitudinal movement of the vice clamps,
while they may be moved laterally upon the bolt to make room for the
saw; the latter when inserted is clamped by the aforesaid wedges, which
are combined with a strong semicircular connection at their smaller
ends, and moved by a screw K and hand wheel K' located centrally in
the rear. By this means the vice clamps are closed upon the saw with
great force when the wedges are drawn back by the screw and wheel.
The side standards are provided with ways, which are planed to receive
the cross head G, which slides vertically therein and is made in a

page_text: compact form to hold two independent arbors L, each provided with a
pulley L driven by a counter pulley L upon a swinging shaft, above
which is connected and moved with the cross head by means of two-
rods L attached to the top corners of the cross head. Each arbor upon
its inner end is formed with screw threads to receive a cutter L' (ono
being a right and the other a left handed screw). The said cutters are
independent. of each other, and when brought together while working
will cut a tongue of a V form. These cutters must be made of suitablo.
diameter to make both sides of the incision in the plate A at the same
time. The inner end of each arbor is also made with a collar L and
provided with a wedge-shaped washer L, which has a flat bearing
against the collar, its taper side lying in contact with a taper fork N.
planed to the same angle but reversed in position; this fork slides
against the end of the box O, which holds the arbors; the said fork being.
moved down from above by a screw P moves the arbors inward to the.
saw plate, while when drawn up by the screw the arbors are moved.
outward from the saw by means of springs Q having forked ends bearing
against the inner side of the hub of the driving pulleys fixed on the
arbors. Thus each cutter is made independently adjustable. Tho:
screws P which move the wedges N have graduated dials P' with index.
hands and small wheels Ps at the top of the cross head G to show the
distance that the arbor is moved to the thousandth part of an inch; thus
by turning the index hand by the small wheel the most accurate adjust-
ment is made in a moment without the least difficulty, thereby locating.
the cutters centrally for fitting the teeth. To
and replacing of the cutters L' the forked
disconnect and turn away from the screw P;
drawn from the machine, and ample room is
cutters. It is very important that the bottoms of the teeth should all
bear the same relation to the centre of the saw; to provide for this the
I cross head G is furnished with a round sliding bar R, which moves
through boxes R' directly above the arbors Land parallel with the same.
This bar is supplied with an apron S secured permanently thereto; the
said apron is provided at the lowest part with a tempered steel broach St
made of the proper form and with teeth, see Figures 29 and 30, to finish
the incision in the saw plate for the base of the tooth. The sides of this
broach are ground perfectly accurate, being each the same distance from
the centre of the bevelled teeth; and in order that the broach S¹ may
allow the ready removal.
wedges N are made to
they may then bo with-
afforded to change the

page_text: always cut with the same relation to the centre of the saw plate the
sliding clamps are fitted next to the saw with steel plates E', as shewn
in Figures 31, 32, and 33, which are adjusted by set screws Es to their
proper position, and are cut through and ground to fit the broach S'.
These steel plates being set centrally with the cutters I of the machine
the broach S is lowered into the plates, and is moved through the said
plates, cutting out from the bottom of the incision made for the teeth
more or less according as it is regulated by stops on the cross head
provided to arrest it at any desired position. The broach S' is moved by
means of a screw T running into the broach bar and turned by a hand
wheel T, both of which are attached to the cross head by means of a
bracket S³ secured to the top of the same. The apron S and broach S',.
which must necessarily work below the arbors L in cutting the base for
the tooth, are arranged to turn up and fasten with a spring catch while
the cutter descends to finish the sides. To facilitate the operation of
these parts the feed screw U which is turned by a hand wheel U' and
attached to the top of the cross head G, runs through a clamp, nut, or
vice U, Figures 28, 29, and 34, which is attached to the top of the
arch B³, and is made with a sliding key Us, Figure 35, which moving
downward between the limbs of the vice opposite to the screw closes the
vice, so that the cross head G moves only by turning the screw. By
moving the key Us up the vice is opened by a spring, and the cross head
is allowed to move at pleasure. The swing above the machine, which
is connected therewith as hercin-before mentioned, has a weight
attached thereto sufficient to balance both the spring and the cross head
with its appurtenances, and it is thus casily moved upward or downward.
in working the machine.
Having thus fully described my said Invention, and shewn how the
same may be conveniently and advantageously carried into practice,
I wish it understood that I claim,―
First. The improvements in removable or detachable saw teeth,
substantially as herein set forth.
Second. The devices for locking or securing removable or detachable
saw teeth in the saw or plate, substantially as herein set forth.
MIL

page_text: tecth and locking devices, and for forming the recesses or grooves
for their reception in the saw plate, substantially as herein set forth.
In witness whereof, I, the said Samuel Greene Arnold, have here-
unto set my hand and seal, this Eleventh day of April, in the
year of our Lord One thousand eight hundred and seventy.
SAMUEL G. ARNOLD. (L.S.)
Witness,
DAVID SEYMOUR BATCHELOR,
Clerk to Mess. Haseltine, Lake, & Co.,
Southampton Buildings,
London.