Improvements in Sawing Machines.
Year: 1891

page_text: of Application, 27th Oct., 1891--Accepted, 26th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Sawing Machines.
We, VICTOR BEAUREGARD of 62 Sudbury Street Master Machinist, CHARLES
SUMNI R GOODING of 28 School Street, Mechanical Engineer, GEORGE HORACE.
BRYA: T of 79 Milk Street, Manufacturers, Agent, and FRANK CHASE of
108 Sr mmer Street, Manufacturer, all in the City of Boston State of Massachusetts,
United States of America, do hereby declare the nature of the invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of this invention is to drive a circular-saw by means acting directly
on its teeth. To this end, the invention, in substance, consists in the combination
with a gear-wheel of a circular-saw having the front or forward and rear or back-
ward edges of and the open spaces between its teeth all relatively shaped for the
teeth of a said gear-wheel properly located therefor, to enter into said open spaces.
and therein to mesh and work on the rear edges of the teeth and thus from its
rotation to continuously rotate the saw and for the front edges of the saw-teeth to
saw the material suitably presented thereto and all without contact between the
teeth of said gear-wheel and said front edges of the teeth of the saw.
In the drawings, forming part of this Specification,
Figure 1 is a front elevation of a circular-saw of this invention and of a gear-
wheel suitably located and having its teeth in mesh with the teeth of the saw.
Figure 2 is a side elevation, Figure 1.
Figure 3 is a side elevation of the saw and gear-wheel, each only in part and
both enlarged.
In the drawings, a, a are the teeth of a circular saw-blade T. These teeth
encircle the saw and except as to this invention they and the saw are all as usual.
The several teeth of the saw have a front edge, d assuming the saw to be in
rotation as usual and in the direction of the arrows, and the outermost point b of
this edge is adapted to serve as the sawing or cutting portion of the tooth and the
teeth also have a rear edge c. f, f are open spaces or notches between the saw-
teeth. Each open space f is bounded by the front edge d of one tooth and the
rear edge c of the tooth next directly in advance of the tooth having said front
edge and by a bottom edge g joining said front and rear edges. The rear edge c of.
each tooth is formed, preferably as shown, that is with a convex curve that is
tangential to the circular periphery of the tooth of which it is the rear edge and
with a greater or less curve k, preferably one approximating a straight line, in
continuation of said convex curve and meeting tangentially a more or less semi-
circular formed innermost or bottom edge g of the space and by which said rear
edge c of the one tooth is joined to the front edge d of the other and the tooth
next following. The front edges d of the several teeth are formed, preferably as
shown, that is for their outermost points 6 as before stated to be capable of sawing
or cutting and from said points with a more or less concaving curve meeting
tangentially the semicircular innermost edge g of the space between the tooth
to which said front edge belongs and the back edge of the tooth next in advance
thereof.
I is a vertical gear-wheel having teeth m and all otherwise as well known. This
gear-wheel, as shown, Figure 3, is arranged above and Figure 1 at one side of the
saw and in a vertical plane coincident with the vertical plane of the saw and other-
wise for its teeth to enter into the open spaces f between and to mesh with and to
bear against and work on the rear edges of the teeth of the saw and thus with
the gear-wheel being suitably driven, to drive and rotate the circular-saw in the
direction stated.

page_text: The rear and front edges k, d of the teeth and the spaces between said edges
all and severally shaped substantially as described, allow of the mesh of the teeth
of the gear-wheel with the teeth of the saw in a manner ensuring proper contact
of the gear-teeth with the rear edges k of the saw-teeth so as to drive the saw and
to pass from said rear edges and out of the open spaces f between the teeth so as
to have no contact between them and the front edges d of the saw-teeth.
For the practical working of the circular saw T and gear-wheel I arranged
together as described obviously a suitable support for both is to be provided, as for
illustration, Figure 2, a frame F on which they are both held and adapted to rotate
the saw from the rotation of the gear-wheel and the gear-wheel from the power.
suitably applied to it.
It is preferable and so shown, that the teeth of the gear-wheel shall not have
contact with the periphery of the saw teeth and that the depth of the spaces f
between the saw-teeth shall be sufficient to permit the gear-wheel, it having been
properly adjusted therefor, to mesh and work on the backward edges k of the saw-
teeth as described so that if the saw wears away or is ground off upon its
periphery h, the gear I may be adjusted nearer to the centre of the saw and still
leave clearance between the crown or outermost portions of the teeth m of the gear
and the root or bottom edge g of the spaces f.
Among many advantages secured by an adaptation of the teeth of a circular-saw
for the application of a gear-wheel to its teeth and thereby to drive the saw all as
has been described, may be mentioned the following.
First. That the full power of the driving gear-wheel is transmitted to the saw ag
it operates the saw at its most efficient portion.
Second. That the attaching of the saw to its shaft is not necessarily required to
be as rigid as when the saw is driven by its shaft.
Third. That the saw is subjected to less strain and has less tendency to spring or
break.
Fourth. That the material to be sawed can be placed more closely to the axis or
centre of the saw than it can be when the saw is driven by its shaft as heretofore
thus enabling saws of much smaller diameter to be used than otherwise would
be possible.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is,
t
In a sawing machine, the combination with a circular-saw having teeth with fron
and rear edges d, c and spaces f between them all essentially as described of a
gear-wheel suitably adapted and located to mesh and work on the rear edges of
said saw-teeth and thereby to drive said saw, substantially as described, for the
purposes specified.
Dated this Seventh day of July A.D. 1891.