Improvements in Circular and other Saws.
Year: 1888

page_text: States of America, Merchant.]
Improvements in Circular and other Saws.
1, HENRY HARRIS LAKE, of the firm of Haseltine, Lake and Co., Patent Agents of
Southampton Buildings, in the County of Middlesex do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention relates to the construction and arrangement of the teeth and the
spaces between the teeth, and has for its object to produce a saw having teeth of such
a character as will be strong and durable, and will work with equal facility crossways
or lengthways of the grain, will answer all purposes of a saw for general purposes,
and will work with less power than the ordinary saw.
Figure 1 is a side elevation of a saw embodying this improvement.
Figure 2 is a detail drawn to an enlarged scale.
Figure 3 is a detail showing a modification.
Figure 4 shows the teeth with parallel sides.
Figure 5 shows part of a circular saw embodying this improvement.
Figure 6 is a cross section of Figure 1 through line a, a, looking in the direction
indicated by the arrow, showing the teeth without any set.
Figure 7 is a similar view showing the set of the teeth.
The teeth a and b are made with a cutting or knife edge the entire length of their
front sides and at one edge thereof and the cutting edge is in advance of the opposite
edge, this is done by bevelling the front side of the tooth. One tooth is bevelled to
the right, and the other is bevelled to the left. This makes the cutting edge of one
tooth on one side of the saw and the cutting edge of the next tooth on the other side,
and so on.
The incline of the bevelled surface on each cutting tooth is sufficient to
make a clear cutting edge on each tooth. The cutting teeth a and b are arranged in
sets of two each. Immediately in the rear of each set of cutting teeth is a chisel or
clearing tooth e made with front and rear edges parallel or nearly so, and in its length
inclining to one side of a line directly across and through the depth of the blade of the
Price 8d1

page_text: saw. The cutting or clearing edge of this tooth is directly across the travel of the
saw and at the front thereof. The cutting edge of this clearing tooth extends further
down from the blade than the heel thereof.
In front of the clearing tooth is the space or gulley o, made deeper than the space h
between the two cutting teeth. Its depth determines the length of the front edge or
side of the clearing tooth e and the depth between the two cutting teeth determines
the length of its rear edge or side. The clearing tooth e is slightly shorter than the
cutting teeth a, b. In Figure 4 is shown a modification of the shape of the spaces
between the different teeth. The cutting edges of the teeth are not changed from
those shown in the other figures. The set of the cutting teeth is as follows. The
cutting edges of the teeth are so adjusted in the set, that they are parallel or nearly so,
with the sides of the saw. In the ordinary way the ends of the teeth are inclined to
the right and left, and the sawing is done by the sharp ends of the teeth tearing or
breaking the wood whereas in this improvement the cutting edge of each cutting
tooth is set to the right and left, so that they are parallel or nearly so with the sides of
the saw.
and are the cutting edges of the cutting teeth. In Figure 6 they have
not been set out, hence they are in the same plane with the sides of the saw. In
Figure 7 they have been set out; the cutting edges i and are parallel with the sides
of the saw but not in the same plane. The cutting edges each being in the same
plane throughout its entire length, divide the wood by cutting it in contra distinction
to the ordinary tooth which tears or breaks it apart. With this improvement a smooth
side is left. In using the old fashioned sharp pointed tooth, a velvety or rough side
is left, which greatly clogs the saw, requiring more power to use it. In Figure 7 the
set is shown larger than it really is in use. This being necessary to make clear the
illustration. A very slight set is all that is required.
The cutting tooth a cuts a gash at one side of the space cut away by the saw the
cutting tooth b, cuts a gash on the opposite of this and parallel with it, leaving the
wood between these gashes untouched. The clearing tooth e, immediately following
clears out the space between the gashes. The space o, in front of the clearing tooth
affords store room for the saw dust until it passes beyond the edge of the wood
being cut.
It will be observed that the office of the cutting teeth a, and b, is to cut gashes at
each side of the space cut away by the saw, and the office of the clearing tooth e is to
clear out the space between these two gashes. The teeth a and b being provided with
knife edges cut the fibres of the wood directly, and do not tear or break them off, as
is done by the teeth in an ordinary saw, thus the sides of the space cut away by the
saw are left comparatively smooth, and free from the rough or velvety character
shown by cuts made by the ordinary saw.
It is manifest then that this saw will do the work with less power than the old form
of saw, because of the smoothness of the sides left by sawing. For the same reason
also less set is required in the saw, and consequently a thinner or narrower space is
cut away which makes a saving of material. It will be observed that I use two
distinct varieties of teeth and arrange them in groups of three each, two of each group
being of one variety, and the remaining one being of the other variety. Also the
cutting teeth have the draw cut made so by the cutting edge extending backwards
from its lower end. The space or gully between these sets of teeth and in front of
the clearing teeth, is loop form having the lower or extreme end oval and the sides are
directly across the blade of the saw. The chisel or clearing tooth is made like the
body of an ordinary mortising chisel, with its cutting edge extending directly across
the travel of the saw. The cutting edge of each cutting tooth faces the rear flank
edge of the tooth in advance.
Having now particularly described and ascertained the nature of the said inven-
tion 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 :-
First. As an article of manufacture a saw provided with two kinds of teeth viz.
cutting teeth and clearing teeth, the cutting teeth being divided and defined by an

page_text: angular space and provided with alternate cutting edges facing the flank rear edge of
the opposite cutting teeth, the clearing teeth being chisel shaped with parallel front
and rear edges, the rear edge being shorter than the front edge, placed at a slight
angle with the radius and direct line across the body of the saw, slightly chamfered at
the end to form a cutting edge next to the gulley and directly across the travel of the
saw and a little shorter than the cutting teeth, each set of teeth being divided by a
gully extending deeper into the blade than the other divisions, at the same angle with
the radius, and direct across the blade of the saw, capable of being filed or cut deeper
into the blade as required and the sides of which are not bevelled but directly across
the travel of the saw.
Second. A saw provided with two cutting teeth in step form, the longer sides of
which are bevelled respectively to the right and left, forming cutting edges on the
outer edges thereof, and extending from the base of the short side backwards and
upwards from the travel of the saw in a direct line, at an angle of about forty five
degrees, and a chisel tooth with a cutting edge on the front edge thereof, and directly
transverse of the blade of the saw, a little shorter than the cutting teeth, the end of
said tooth inclining back from its transverse edge to the lower end of the incline of
the adjoining cutting tooth and in opposite direction, and a gully in front of chisel
tooth with square edges.
Third. A saw having parallel edged acute angle cutting teeth and parallel
edge chisel form teeth, having a transverse cutting front and shorter than the cutting
teeth.
Fourth. A saw having its cutting teeth set with their cutting edges parallel or
substantially so with the sides of the saw and out side of the plane of the sides of the
said saw.
Daind th:
J
1
1000