IM- PROVEMENTS IN SAW TEETH
Year: 1856

page_text: PROVISIONAL SPECIFICATION left by William Henry Walenn at the
Office of the Commissioners of Patents, with his Petition, on the
19th February 1856.
I, WILLIAM HENRY WALENN, of 68, Chancery Lane, London, in the County
of Middlesex, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN SAW TEETH," a communication from Nelson Barlow, of Newark,
United States, to be as follows:
This Invention relates to the teeth of saws, and consists in forming improved
cutting edges upon the opposite sides of saw teeth by means of a grooved recess
or space between said sides, and also in bevelling or rounding the back of the
teeth in a form corresponding to said recess.
Fig. 1 of the Drawings annexed is a slant view of a series of teeth so con-
structed, and suitable for either straight or circular saws; Fig. 2 is a section
of the same; Figs. 3 and 4 are modifications of this improvement; and
Fig. 5 exhibits a method of "setting" the teeth by means of a punch,
which (with light blows) spreads their edges apart sufficiently to give the
required clearance. In these Figures the same letters refer to similar parts.
A recess is formed on the front edge of the tooth, as shown at f, extending
inward as far as the roots of the teeth, i. e., from t to, if desirable, and parallel
with the side of the saw, the shape of which recess, being concave or angular,
gives acute edges upon the sides of the teeth; and to give the best effect to this
improvement the back edges of the teeth, as shown at b, are rounded, in a form
corresponding with the recess, thereby enlarging the cutting extent of the points,

page_text: and rendering each tooth so formed a perfect cutter at whatever angle it may
be presented to the wood. The spaces are formed by means of a steel burring
tool or cutter, with its outer edge of suitable shape to give the requisite form
to the recesses and edges. The burrs or cutters can be used in a convenient
machine, or a tool can be adapted by which the same can be done by hand; or
when the improvement is embodied in teeth having the usual angular form (as
Fig. 4,) a reciprocating cutter may be used instead of the burring tool.
Suitable punches adapted to the different angles of the teeth may also be used
for this purpose, or for "setting" after they are thus formed. Thus, two
distinct tools may be used in forming the teeth, the steel cutter to form the
recess and a punch to "set" the teeth. The teeth may be "set" alternately in
the usual way, but the method before mentioned is preferred. The sides
of the teeth may be made even, and sharpened by passing a file or stone
over their surfaces. When teeth are shaped with circular spaces between
them, as at Figs. 1 & 2, such edges may be formed upon the root and back
edge of the teeth. This is especially adapted to reciprocating saws; or they
may be formed as shewn at Fig. 3, where c represents pairs of cutters alter-
nating with teeth of the usual shape. Other modifications of these cutters may
be used by the formation of the same in pairs upon alternate teeth, or openings
may be made through the saw, having their edges armed with cutters of the
form described.