IMPROVEMENTS IN SAWS AND SAW TEETH
Year: 1867

page_text: LETTERS PATENT to William Robert Lake, of the "International Patent
Office," No. 8, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Consulting Engineer, for the Invention of "IMPROVEMENTS
IN SAWS AND SAW TEETH."-A communication from abroad by Ira
Stillman Brown, Charles Noyes Brown, and John Mason Gross, all of
Providence, Rhode Island, United States of America.
Sealed the 6th December 1867, and dated the 15th June 1867.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, on the
15th June 1867.
I, WILLIAM ROBERT LAKE, of the "International Patent Office," No. 8,
Southampton Buildings, Chancery Lane, in the County of Middlesex, Con-
sulting Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SAWS AND SAW TEETH," a communication, to be as
follows:-
The said improvements relate to saws provided with independent or
removeable teeth which can be attached to the saw plate or disengaged there-
from at pleasure by convenient locking devices.
In all the variations herein-after described, where adjustable removable saw
teeth are employed, it is to be understood that such teeth are to be hardened,
tempered, and ground to a cutting edge.

page_text: The first part of the said improvements relates chiefly to independent or
adjustable teeth for circular saws; the said teeth can be attached to the plate
and held in the required position by a dovetail joint in combination with a
clamp screw. That portion of the tooth which projects beyond the saw plate
is swaged into a form somewhat like the letter S, but with the exterior of the
curves flattened; these flattened portions should be parallel to the plane of
the saw and should be furnished with a cutting edge, and the whole of the
inner curves next in advance of such flattened portions should be bevelled at
the edge. The extent of the flattened portion or chisel edge will depend
somewhat upon the number of these teeth so inserted in the plate. In a
circular saw of medium size one tooth only will be found in most cases to be
sufficient, but whether one tooth or more are used the chisel edge or edges
which come into action during one revolution of the saw should be in
length somewhat in excess of the distance through which the timber to be cut
is fed. When a saw plate has been fitted with one or more teeth of the
character described, and such teeth are set so that their extreme cutting edge
shall be inside the circumference of the circle which bounds the extreme
cutting edges of the other teeth, it follows that as the timber is fed to the
saw a narrow kerf cut by the stationary teeth will always be a little in advance
of the planing teeth. As the latter enter the kerf the curved or gouge-formed
portions of their edges immediately in advance of the chisel edge will widen
the cut and partly smooth it. As the timber is fed forward the chisel following
in the path more roughly dressed by the gouges will plane and smooth the
wood upon each side of the kerf.
The second part of the said improvements relates to a cutting and planing
tooth combined. Each of such teeth is made up of a cutting point and two
planing edges, and the planing edges of any one tooth are arranged to act
upon the opposite sides of the kerf to those upon which the corresponding
planing edges of the next tooth act. The special peculiarity of this tooth is
that each of the planing tools is provided with back irous, which perform the
same useful function as the same device in the well known joiners plane. The
shank of the tooth is secured to the plate of a circular saw in the following
manner: A channel of a form is cut in the edge of the said shank upon
one side and upon its end, and the edges of the opening in the saw plate are
chamfered so as to fit the said channel. Both the edge of the opening and
the edge of the side of the shank for a certain distance are cut with a flat-
bottomed channel, and after the tooth has been inserted a key is fitted into the
space between them.
The said improvements consist, thirdly, in the peculiar form given to that

page_text: portion of the tooth which fits into the saw plate, whereby the action of the
tooth against the wood in cutting a kerf tends to hold it in its seat and prevent
it from jarring loose, and as an incident of this form of shank there is an
absence of salient angles in the fitting portion, whereby greater strength is
secured for the saw plate. In applying these teeth to a circular saw recesses
are formed in the saw plate for the reception of the teeth, which are fitted with
shanks of a hooked form without salient angles, adapted to just fill the recesses
in the said saw plate. The edges of the shanks are grooved and the edges of the
recesses are sharpened, so that when the tooth is inserted in the plate it cannot
be moved laterally. The hook-formed shanks stand with their concave sides
in the direction of the motion of the saw, and consequently any resistance
which the tooth encounters in sawing tends to force the shank more firmly
against the socket in the plate. The shape of the cutting portion of this
tooth differs from the one previously described. Beneath the cutting point the
body of the tooth is bent to stand hard over to one side of the kerf, and is
then formed into a curved cutting edge; this rounded portion acts as a gauge,
as in the case of the S-formed tooth first described, while the straight portion
of the tooth following, after being inclined at an angle with the radial line of
the saw plate, gives a drawing or shaving cut which smooths the surface of the
wood.
The said improvements relate, fourthly, to an improved locking device for
securing a removeable tooth in a saw plate, which device is applicable to
any saw plate provided with inserted teeth. As in the other instances
described the teeth which are to be inserted in the saw plate are provided
with grooves in their edges adapted to receive tongues on the saw plate,
whereby they are prevented from changing their position laterally; it is
necessary however to prevent. the teeth from moving radially, and for this
purpose the locking device herein described is employed. The said device
consists of a sliding bolt fitted to enter a corresponding hole in the edge of
the shank of the tooth; this bolt is kept in place by a tumbler which is
arranged to revolve in the saw plate, and against the surface of which the end
of the said bolt bears; this tumbler has a recess in its side large enough to
admit the bolt for a distance equal to that which the bolt enters the shank.
When the tumbler is turned so that the axis of this recess shall coincide with
the axis of the said bolt the latter can be withdrawn into the recess to allow
the removal of the tooth from the plate. The tumbler revolves in the plate
and its liability to become displaced is prevented by means of a screw cut on
its periphery; this screw fits a female screw in the saw plate, and is so
arranged that when the recess stands opposite to the end of the bolt the end

page_text: surfaces of the tumbler will be flush with the surfaces of the said saw plate.
To prevent the turning of the tumbler so as to release the tooth a spring bolt
in the edge of the saw plate is arranged to enter the recess in the tumbler,
and thus until such spring bolt is forced back the turning of the tumbler is
prevented. To operate the locking device the wedge-shaped key which is
fitted to fill the recess in the tumbler is forced in behind the spring bolt, thus
withdrawing the bolt and permitting the tumbler to be turned by the said
key until the recess is brought opposite the bolt. The key being withdrawn no
obstruction exists to the entrance of the bolt into the recess in the tumbler;
the tooth is then free to be removed. This locking device may be placed in
the tooth instead of in the plate.
The fifth part of these improvements relates to the application of inde-
pendent removable teeth to a reciprocating saw, and consists in so constructing
the teeth of an upright saw that each tooth shall interlock with the next in
the series, so that the teeth are mutually supporting and sustaining, whereby
a saw may be constructed with inserted teeth sufficiently near together to
admit of their adaptation to reciprocating saws. This part of the said
improvements further consists in so arranging a series of removable teeth
in combination with a locking device that several or all of the teeth may be
securely fastened by a single lock, whereby the facilities for removing the
teeth for grinding are greatly increased. The saw plate may be of any
desired length and width, and adapted to be hung and operated in the usual
Banner..
The teeth are separate from the plate, each tooth being a distinct piece,
and fitted with a shauk to fill a square recess in the edge of the plate. Each
tooth besides its root or shank has two projections, one of which extends
backward to the next tooth and interlocks therewith, while the other extends
over and rests upon the projection of the preceding tooth; thus it will be
seen that each tooth interlocks with the teeth on either side of the same in
such manner that it holds the tooth immediately preceding it, and is in its
turn held by the succeeding tooth. To remove any one tooth from the plate
all the teeth above or behind it must first be removed. The end of the shank
is formed into a hook; on each side of the saw plate and covering the hooks
of the teeth a strip is let in flush with the surface. Rivets passing through
these two strips immediately before each hooked shank serve to bind the strips
and hold them firmly in place, and when the said strips are moved to bring
the rivets within the hooks of the teeth each tooth is firmly locked and held
independently of any other in addition to the natural support described above.
To operate these strips an eccentric is employed which is provided with a

page_text: handle, and is connected to the strips and to the plate in such a manner that
by turning the handle and eccentric one half a revolution an end motion is
imparted to the strips. Stops are provided to prevent the said handle fron
making more than one balf a revolution, and this handle is so arranged
relatively to the eccentric that when the teeth are locked it hangs downward,
and the weight of the said handle assists to hold the locking device in place,
and prevent the accidental loosening of the teeth. A portion of the teeth
may be made to act as planes for smoothing the kerf if desired, or the saw
may be readily changed from a common saw into a planing saw by removing
and resetting the teeth or by substituting others, and the teeth may be
removed and sharpened without disturbing the plate or its fastening in the
gate or frame; a number of these saws may be used together in gangs or
sets.
The said improvements relate, sixthly, to an improved means for securing
the teeth in a reciprocating saw, so that instead of each tooth requiring to be
fastened separately the whole series of teeth can be readily secured by a single
lock. Teeth with shanks of a hooking or curved form are fitted into properly
prepared recesses in the saw plate, the edges of the shanks, being grooved, and
the edges of the recesses being sharpened to prevent lateral displacement.
The hooked form shank is so formed and situated relatively to the acting
point of the tooth that any outward and backward pressure upon the point
tends to force the shank more firmly into its socket. On the rear of each
tooth is a projection extending back on the edge of the plate to the next
tooth, and on the front of the tooth is another projection which fits upon and*
overlaps the projection of the preceding tooth, thereby preventing the removal.
of any tooth until the next succeeding tooth is first removed. When the last
tooth in the series is fastened the whole are locked, and no one of them can
be removed. The last tooth in the series is fastened. in the following.
manner: A bolt is fitted to slide upon the edge of the saw plate, which
bolt is provided with guides on either side; a piece riveted thereto is.
adapted to slide in a slot in the said plate. The bolt can slide longitudinally
upon the plate, but cannot be removed therefrom without destroying it; the
end of the said bolt fits the projection of the last tooth in the series, and thus.
holds it in place; a cam is provided to operate this bolt.
The said improvements relate, seventhly, to a "cutting-off" saw tooth.
which may be applied to a circular saw plate in place of the tooth described.
in the third part of this Specification. It will be unnecessary to describe the
crooked shauk of this tooth, or the manner in which the same is secured in
the plate, as in these respects it does not differ from some of the teeth already..

page_text: described. The peculiarity of the said tooth consists in combining with the
cutting point two scoring teeth with triangular points set respectively in
opposite sides of the tooth. In action these scoring teeth will strike the
timber first and cut the fibre of the wood upon each side of the kerf after the
manner of the teeth of the ordinary cross-cut saw; as the channel so
formed becomes deeper the chisel point will scoop out the chips and complete
the kerf.
The said improvements relates, eighthly, to a burnishing tooth, which is
especially designed for use in connection with saws used to cut veneers or
wherever it is desired to give a polished and perfectly smooth surface to the
wood which is cut. The shank of the tooth is inserted into a saw plate and
secured in the manner already described; instead, however, of being provided
with cutting edges it is furnished with a pair of spring burnishers whose ends
are rounded upon the outside; these burnishers will enter the kerf which
has been cut by any of the cutting teeth before described. The edges of their
ends stand near enough together for the purpose, but their sides being thicker.
will occupy a wider space, so that the tendency of the sides of the kerf will be
to bring the spring part of the burnishers nearer together. In saws of medium
size only one of these burnishers will be required, but more may be introduced
if found desirable.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Robert Lake in the Great Seal Patent Office
on the 12th December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Consulting Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of June, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said William Robert Lake, Her special licence that I, the said William
Robert Lake, my executors, administrators, and assigns, or such others as I,
the said William Robert Lake, 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

page_text: make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention of "Im-
PROVEMENTS IN SAWS AND SAW TEETH," upon the condition (amongst others).
that I, the said William Robert Lake, 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 Robert Lake, 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 Sheet of
Drawings forming a part of this Specification :-
The various descriptions of saw teeth, which are illustrated in the said
Drawings, all relate to that class which are independent of the saw plate, but
which can be attached thereto or disengaged therefrom at pleasure by con--
venient locking devices. In all the instances lerein-after described where
adjustable removable saw teeth are employed it is to be understood that such
teeth are to be hardened, tempered, and ground to a cutting edge.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a view of a portion of a circular saw with one form of my
improved tooth inserted therein; Figure 1¹ is an edge view of the same tooth;
Figure 2 represents a cutting and planing tooth combined; Figure 2¹ is &
back view of the same; Figure 2" is a front view of the said tooth; Figures 2111
and 2 are keys for assisting the removal of the lock which holds the tooth
in the plate; Figure 3 illustrates another form of a combined cutting and
planing tooth; Figure 31 is a front view of the same; Figure 4 illustrates an
improved locking device for securing a tooth in a saw plate; Figure 4¹ is an.
edge view of the saw tooth and plate; Figure 4" is an enlarged section of the
locking device; Figure 5 represents an upright saw with removable teeth and
a means for locking the same to the plate; Figures 51, 5, and 51,. are
detailed parts of the same; Figure 6 represents an improved means for
securing independent teeth in a reciprocating saw; Figure 7 represents a
"cutting-off" saw tooth; Figure 8 represents a burnishing saw tooth.
In Figure 1 A represents a portion of the plate of a circular saw with fixed
teeth B of any preferred form. The improved tooth C is independent of the
plate, but can be attached to it and beld in the position shown in the Drawing

page_text: by a dovetail joint in combination with a clamp screw c. That portion of
the tooth C which projects beyond the saw plate is swaged into a form some-
what like the letter S, but with the exterior of the curves flattened, as repre-
sented clearly in Figure 1'. These flattened portions E and F should be
parallel to the plane of the saw, and should be furnished with a cutting edge,
and the whole of the inner curves next in advance of such flattened portions
should be bevelled at the edge. It will thus be seen that the two members
making up the S-shaped tooth consist respectively of a chisel and gouge in
combination. The extent of the flattened portion or chisel edge will depend
somewhat upon the number of these teeth so inserted in the plate. In a saw
of medium size one tooth only will be found in most cases to be sufficient, but
whether one or more are used the chisel edge or edges which come into action
during one revolution of the saw should be in length somewhat in excess of
the distance through which the timber to be cut is fed.
Supposing now a saw plate to have been fitted with one or more teeth of
the character described, such teeth being set so that their extreme cutting
edge shall be inside of the circumference of the circle which bounds the
extreme cutting edges of the other description of teeth, it follows that as the
timber is fed to the saw a narrow kerf cut by the stationary teeth will always
be a little in advance of the planing teeth. As these latter teeth enter the
kerf the curved or gouge-formed portions of their edges e and f immediately
in advance of the chisel edge will widen the cut and partly smooth it. As the
timber is fed forward the chisel following in the path more roughly dressed by
the gouges will plane and smooth the wood upon each side of the kerf. Inas-
much as the cutting edges of the tooth described act upon both sides of the
kerf at the same time there is no tendency in their action to spring the saw,
and the ogee or S form which is employed is highly favourable for the free
discharge of the chips which are formed.
In Figure 2 there is represented a cutting and planing tooth combined. A
is a section of a circular saw plate, and B, B', are two of the teeth, which are
to be inserted therein. Each of such teeth is made up of a cutting point a
and two planing edges b, b¹, and the planing edges of any one tooth are
arranged to act upon the opposite sides of the kerf from those upon which the
corresponding planing edges of the next tooth act. Thus the cutting point of
the tooth B striking the timber opens a kerf, the two sides of which are planed
by the planing tools 6, 61. The point of the next tooth cuts a similar kerf,
but the planing tools of this tooth serve to balance the saw and keep it from
springing by having their positions reversed with reference to the positions of
the planing tools of the preceeding tooth. The special peculiarity of the tooth

page_text: here shown is that each of the planing tools b, b', is provided with back irons
c, c', which perform the same useful functions as the same device in the well-
known joiners' plane. The shank of the tooth is secured to the saw plate as
follows: A channel of a V form is cut in the edge of the shank upon one
side and upon its end, and the edges of the opening in the saw plate are
chamfered so as to fit it. Both the edge of the opening and the edge of the
side of the shank from d to e are cut with a flat-bottomed channel, and the
space after the tooth has been inserted is fitted with a key f, as shown.
In Figure 3 is represented another form of cutting and planing tooth
combined, exhibiting certain special peculiarities. So far as this tooth is
detachable from the plate and capable at pleasure of being removed therefrom
it is similar to that last above described; its novelty consists in the peculiar
form given to that portion of the tooth which fits into the saw plate, whereby
and as the result of such form the action of the tooth against the wood in
cutting a kerf tends to hold it in its seat and keep it from shaking loose, and
as an incident of this form of shank there is an absence of salient angles in
the fitting portion, whereby greater strength is secured for the saw plate. A is
a section of a circular saw plate, with the recesses formed therein for the
reception of the teeth; B, B', are the teeth fitted with shanks of a hooked
form without salient angles, adapted to just fill the recesses in the saw plate, as
shown. The edges of the shanks are grooved and the edges of the recesses
are sharpened, so that when the tooth is inserted in the plate it cannot be
moved laterally. It will be observed that the hook-formed shanks stand with
their concave sides in the direction of the motion of the saw, and conse-
quently any resistance which the tooth encounters in sawing tends to force the
shank more firmly against its socket in the plate. The shape of the cutting
portion of the tooth here shown differs from the one previously described.
Beneath the cutting point d the body of the tooth is bent, so as to stand hard
over to one side of the kerf, and is then formed into a curved cutting edge e,f;
this rounded portion acts as a gouge, as in the instance of the S-formed tooth
first described, while the straight portion of the tooth which follows after is
inclined at an angle with the radial line of the saw plate, and gives a drawing
or shaving cut which perfectly smooths the surface of the wood.
In Figures 4, 4, 4", an improved locking device for securing a removable
tooth in a saw plate is shown; this part of my Invention is applicable to any
saw plate adapted for the use of inserted teeth. As in the other instances
described the teeth B, which are to be inserted in the saw plate A, are provided
with grooves s in their edges adapted to receive tongues on the saw plate, whereby
they are prevented from changing their position laterally. It is necessary

page_text: •
however to keep the teeth from moving radially, and for this purpose the
locking device herein described is employed. The said device consists of a
sliding bolt a fitted to enter a corresponding hole in the edge of the shauk of
the tooth; this bolt is kept in place by a tumbler C, which is adapted to revolve
in the saw plate, and against the surface of which the end of the bolt a bears;
this tumbler has a recess cut in its side large enough to admit the bolt for a
distance equal to that to which the bolt enters the shank. When the tumbler
is turned so that the axis of this recess shall coincide with the axis of the bolt
the latter can be withdrawn into the recess, and will allow the removal of the
tooth from the plate. The tumbler C is fitted to revolve in the plate (without
being liable to become displaced) by means of a screw cut on its periphery
fitting a female screw in the saw plate, and so arranged that when the recess
stands opposite to the end of the bolt a the end surfaces of the tumbler will be
flush with the surfaces of the said plate. To prevent the friction or jarring of
the saw when in action from the turning of the tumbler to release the tooth a
spring bolt located in the edge of the saw plate is arranged to enter into
the recess in the tumbler, and thus until such spring bolt is forced back the
turning of the tumbler is prevented. To operate the locking device the
wedge-shaped key, Figure 41, fitted to fill the recess in the tumbler C is forced
in behind the spring bolt b, thus withdrawing the bolt and permitting the
tumbler C to be turned by such key until the recess is brought opposite the
bolt a.
The key being withdrawn no obstruction exists to the entrance of the
bolt a into the recess in the tumbler. The tooth is then free to be removed.
This locking device may be located in the tooth instead of in the plate, but it
will be found better to arrange it as shown, as it will when located in the
plate answer for any number of different teeth which may be fitted to the
same plate.
In Figure 5 is represented one form of the independent removable teeth
The nature of this
and the application of the same to a reciprocating saw.
part of my Invention consists in so constructing the teeth of an upright saw
that each tooth shall interlock with the next in the series, so that the teeth
are mutually supporting and sustaining, whereby it is rendered practicable to
construct a saw with inserted teeth sufficiently near together to admit of their
adaptation to reciprocating saws; and it further consists in so arranging
a series of removable teeth in combination with a locking device that
several or all of the teeth may be securely fastened by a single lock, whereby
the facilities for removing the teeth for grinding are greatly increased.
A is the saw plate which may be of any desired length and width, and
adapted to be hung in and operated by a gate in the usual manner.
The

page_text: teeth B are separate from the plate, each tooth being a distinct piece and
fitted with a shank 6 to snugly fill a square recess in the edge of the plate, as
shown. Each tooth B besides its root or shank 6 has two projections, one of
which c extends backward to the next tooth, interlocking therewith, the other d
reaching over and resting upon the projection c of the preceeding tooth. Thus
it will be seen that each tooth interlocks with the teeth on either side of it in
such manner that it keeps the tooth immediately preceeding it from being
removed from the plate, and is in its turn held in a like manner by the suc
ceeding tooth. The projection c interlocking with the shank b of the succeeding
tooth gives a rigidity to the structure beyond what could be obtained in the
narrow limits allowed for the shank b, where the teeth are necessarily so
thickly set as in a reciprocating saw. To remove any one tooth from the
plate it will be observed that all the teeth above or behind it must first be
removed, which fact gives great security, against the accidental loosening of
the teeth in use. The end of the shank b is formed into a hook e, more
plainly seen in Figure 5". On each side of the plate. A, and covering the
hooks e of the teeth, a strip F is let in flush with the surface, as shown in
section, Figure 5. Rivets f passing through these two strips F, imme.
diately before each hooked shank e, serve to bind the strips F, and hold them
firmly in place, and when the strips F are moved so as to bring the rivets f
within the hooks e of the teeth B, as shown in Figure 5, each tooth is firmly
locked and held independently of any other, in addition to the natural support
described above. To operate these strips an eccentric G is employed at the
upper end thereof, which eccentric is operated by a handle I, and is connected
to the strips F and the plate A, so that by rotating the handle I through one
half a revolution an end motion is imparted to the strips F. Stops i, i, are
provided to keep the handle I from making more than one-half a revolution,
and this handle is so arranged relatively to the eccentric G, that when the
teeth are locked it hangs down as represented. By this means the weight of
the said handle assists in holding the locking device in place, and prevents the
accidental loosening of the teeth. A portion of the teeth B uay be made to
act as planes for smoothing the kerf if desired, or the saw may be readily.
changed from a common saw into a planing saw by removing and resetting.
the teeth, or by substituting others, and the teeth may be removed and
sharpened without disturbing the plate or its fastening in the gate. A number
of these saws may be used together, forming gangs to better advantage than
the ordinary reciprocating saws, because of the ability to remove the teeth
and sharpen them without altering or disturbing the position of the plates.
The modification of my Invention exhibited in Figure 6 has for its object

page_text: an improved means for securing the teeth in a reciprocating saw, so that
ins ead of each tooth requiring to be fastened separately, the whole series of
teech can be readily secured by a single lock.
A is the saw plate, and B are teeth having shanks 6 of a hooked or curved
form fitting into properly prepared recesses in the plate A, the edges of the
shanks being grooved, and the edges of the recesses being sharpened in the
usual manner to prevent displacement laterally. This shank bis so formed
and situated relatively to the acting point of the tooth that any outward and
backward pressure upon the point tends to force the shank more firmly into its
socket. On the rear of each tooth is a projection 6' extending back on the edge
of the plate A to the next tooth, and on the front of the tooth is a projection bu
which fits upon and overlaps the projection 61 of the preceeding tooth, thereby
preventing the removal of any tooth until the next succeeding tooth is first
removed. As each tooth thus serves as a lock for the preceeding tooth, when
the last tooth in the series is fastened the whole are locked, and no one of
them can be removed. The last tooth in the series is fastened in the following
manner: A bolt C is fitted to slide upon the edge of the plate A, baving
guides c on either side, and a piece c' riveted thereto and adapted to slide in
a slot in the plate A, as shown. This arrangement is such that while the
bolt C can slide longitudinally upon the plate A it cannot be removed there-
from without destroying it. The end of the bolt C is adapted to fit upon the
projection 6 of the last tooth in the series, and thus holds it in place. A cam
D is provided to operate the bolt C in a well-known manner.
It will be seen
that the strain upon each tooth due to the action of the tooth in sawing is
received upon its own shank, the said action tending to force the tooth more
firmly into its place, but any tendency of the tooth to become loosened is
resisted by the overlapping piece 6" of the succeeding tooth. It will also be
seen that any force exerted to remove a tooth in coming upon the succeeding
tooth acts in the same manner upon the latter as does the resistance of the
wood in sawing, that is to say, it forces it more firmly into its socket. . Thus
the teeth are held in such manner that while the last one of the series is
securely locked no tooth in the series can be removed, and all strains thereon
only tend to confine them more securely.
In Figure 7 is exhibited a "cutting-off" saw tooth, which may be applied
to a circular saw plate in place of the tooth shown in Figure 3. It will be
unnecessary to describe its crooked shank or the manner in which the same is
secured in the plate, as in these respects it does not differ from some of the
teeth already described. Its peculiarity consists in combining with the cutting.
point a two scoring teeth b, b, with triangular points set respec ively on

page_text: opposite sides of the tooth. In action these scoring teeth will strike the
timber first, and cut the fibres of the wood upon each side of the kerf after the
manner of the teeth of the ordinary cross cut saw. As the channel so formed
becomes deeper the chisel point a will scoop out the chips and complete the
kerf.
In Figure 8 is exhibited a burnishing tooth, which is especially designed
for use in connection with saws used to cut veneers or wherever it is desired
to give a polished and perfectly smooth surface to the wood which is cut. The
said tooth consists of a shank A which is inserted in a saw plate and secured
in the manner already described; instead however of being provided with
cutting edges it is furnished with a pair of spring burnishers a whose ends
are rounded upon the outside; these burnishers will enter a kerf cut by any of
the cutting teeth before described. The edges of their ends stand near enough
together for this purpose, but their sides being thicker will occupy a wider
space, so that the tendency of the sides of the kerf will be to bring the spring
part of the burnishers nearer together. The resistance of the springs to this
compression will cause the requisite amount of friction to be developed to give
a smooth and polished surface to the wood. It is quite obvious that the
precise form shown in the Drawing need not be employed, as any form of
burnisher arranged to act upon the principle described will accomplish the
result. In saws of medium size only one of these burnishers will be required,
but more may be introduced if found desirable.
Having thus fully described the said improvements as communicated to me
by my foreign correspondents, and shown how the same may be conveniently
and advantageously carried into practice, I claim,-
First, the employment in saws of one or more planing teeth, having a section
at right angles to the line of motion of a form analagous to the letter S, so as
to present separate cutting surfaces for each side of the kerf so nearly opposite
as to support each other, and so arranged that each of the two cutting edges
bas a separate and independent passage for the escape of its chips, substantially
as described.
Second, a planing saw tooth composed of an equal number of chisels and
gouges, arranged alternately with regard to each other, substantially as
described.
Third, a cutting and planing saw tooth in combination composed of a
cutting point and two or more planes provided with back irons, arranged
alternately to each other for the purpose and substantially as described.
"
Fourth, a saw tooth having a curved root or shank, substantially as shown
in Figure 3, so that any resistance applied to the point of the tooth tangential

page_text: to the line of motion of the saw plate shall tend to force the tooth more firmly
into its socket.
Fifth, in combination with a saw plate and a removable tooth a locking
device adapted to lock or fasten the tooth after being placed in position, and
arranged to allow of the removal of the tooth without necessitating the removal
of the locking device from the tooth or plate in whichever it may be situated,
substantially as described.
Sixth, the bolt or tumbler C and spring catch a or equivalent devices in
combination with a removable saw tooth and a saw plate, substantially as
described.
Seventh, a saw tooth B, Figure 5, so constructed as to interlock with the
next adjacent teeth on either side, and be sustained thereby substantially in
the manner herein set forth.
Eighth, the arrangement of the locking device F, f, G, or equivalent
mechanism in combination with removable saw teeth, by which several or all
of the teeth may be fastened by one operation, substantially as described.
Ninth, the combination of the curved shank 6 with projections 61, 611
(Figure 6), and means for locking or fastening the last tooth in the series, the
whole operating together substantially in the manner and for the purposes set
forth.
Tenth, the removable "cutting-off" saw tooth (Figure 7) constructed and
arranged in combination with a saw plate, substantially as set forth.
Eleventh, the burnishing tools (Figure 8), in combination with a saw plate
provided with cutting teeth, substantially as described.
In witness whereof, I, the said William Robert Lake, have hereunto
set my hand and seal, this Twelfth day of December, in the year of
our Lord One thousand eight hundred and sixty-seven.
WILLIAM ROBERT LAKE. (L.S.)
Witness,
THO. N. PALMER,
Clerk to Messrs. Haseltine, Lake, & Co.,
8, Southampton Buildings, W.C.