Year: 1886

page_text: I ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention (a communication from
Alexander Bertram of Toronto, Canada, Merchant) 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 design a fast-cutting saw capable of cutting
so clean a parting that but little friction is produced, and that the same saw may
be used for either cross-cut or ripping purposes; and it consists, essentially, of a
series of ploughing or mortise teeth, the cutting-edges of which are substantially
at right angles to the surface of the saw, each mortise or ploughing tooth being
preceded by two or more chisel-shaped teeth, the cutting edges of which are
alternately formed on the opposite sides of the surface of the saw and are bevelled
in the opposite direction to that in which the mortise-teeth are sloped, so that each
chisel-shaped tooth shall be applied to its work in exactly the manner in which a
turning-chisel is set, thereby ensuring a clean cut down the walls of the parting
made by the mortise or ploughing teeth.
Figure 1, is a perspective view, showing these improved teeth applied to a
straight saw.
Figure 2 is a similar view of these improved teeth applied to a circular saw.
In the drawing I represent merely segments of saws, as they are sufficient to
exhibit the principle of this invention. I have shown two chisel-teeth, A. placed
between each pair of mortise or ploughing teeth, B, but of course it will be under-
stood that more than two may be so placed between each pair of mortise teeth,
the cutting edges of the said chisel teeth being formed on opposite sides of
the saw.
The arrows indicate the direction in which the saws move when cutting, and it
will be noticed that the cutting edges, b, of the mortise teeth, B, are formed
substantially at right angles to the surface of the saw, and that the outer or top
edge of these teeth is bevelled or sloped down from the cutting edge, b, so as to
leave clearance behind the cutting edge.

page_text: It will further be noticed that the cutting edges of the teeth A are sharpened
from the side or surface of the saw and being sharpened on different sides alternately
the walls of the parting on either side of the mortice or ploughing teeth, B, are
shaved by the action of the chisel-teeth, A, the cutting edges of which, it should be
further noticed, are bevelled or sloped in the opposite direction to that in which the
end or top of the teeth, B, are sloped, so that in actual work each tooth acts in
precisely the same manner as an ordinary turning chisel, thereby making so clean
a cut down the walls of the parting formed by the saw that a minimum amount of
friction is produced by the working of the saw, and the Baw itself may be used
either for cross-cutting or ripping purposes.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent I declare that what I claim is
1. A series of mortise or ploughing teeth, B, shaped substantially as shown, and
separated by two or more chisel-shaped teeth, A, shaped and operating substantially
as and for the purpose specified: