Improvements in Saws Ior Cutting..
Year: 1895

page_text: Date of Application, 31st May, 1895-Accepted, 13th July, 1895
Improvements in Saws Ior Cutting. Steel.
I, JOSHUA OLDHAM, a citizen of the United States, residing at Brooklyn, in the
County of Kings and State of New York, United States of America, Manufacturer,
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:
My invention relates to improvements in circular saws more especially for awing
or cutting cold steel, which is also equally applicable to straight saws, the object and
nature of which will appear further on.
Since the introduction of circular saws, known to the trade as milling saws for
sawing cold steel, the great obstacles to their more general use have been the difficulty
of making the saws hard enough for the intended purpose, and the breaking of saws
during the process of manufacture and while at work. The properties of saw steel
do not allow of a sufficiently high temper required for the cutting or sawing of cold
steel, except at the extreme points of the teeth, which, when worn, necessitate the
re-hardening of the entire blade which, with the chances of its breaking during
this operation, together with the deterioration of the steel by repeated annealing
and re-hardening, makes its success very uncertain.
Saws of a greater thickness than necessary or desirable have been made with
inserted cutters or teeth. The space between the cutting points of such teeth,
however, being too wide to allow of quick feed, their work is that of a lathe-tool,
rather than that of a saw.
Therefore, this invention has for its object the making of a saw by or in which a
high tempered tool-steel may be used in the making of the teeth, and regular saw-
steel for the body of the blade, or circular plate-proper.
To this end my invention consists of a tooth of an entirely new character, whose
details of construction and method of work will be hereinafter more fully disclosed
and specifically pointed out in the claim.
In the accompanying drawings :-
Figure 1 is a view of a broken away portion of a circular saw, more especially
designed for sawing or cutting cold steel, embodying my invention.
"
Fig. 2 is an enlarged vertical section thereof on the line x-x of Fig. 1.
Fig. 3 is a detached perspective view of one of the teeth or cutters.
Fig. 4 is a section taken on the irregular line y-y of Fig. 1.
Fig. 5 is a view showing my invention, as applied to a straight saw,
away portion of which, only, is shown.
a broken
In carrying out the invention, I produce the disk-portion, proper, A of a
circular saw, with the usual notches or slots a indenting its circumference or
edge at the proper intervals, for the reception of the inserted teeth or cutters.
I employ an inserted tooth or cutter B of peculiar construction, the same having in
addition to the usual inward extension 6, an arcuate having its outer or peripheral
edge armed with a series or plurality of teeth 62 and adapted to conform to the
periphery of the disk A, each tooth or cutter thus forming an approximate right-
angle, with the toothed arcuate extension 6 filling in the unoccupied interval left
between the teeth, or cutters as previously constructed, thus producing a set of
teeth of a practically unbroken continuity around the entire circumference of a

page_text: circular saw or along the edge of a straight saw, in the latter case, the inserted
tooth, of course, being a perfect right angle, as seen in Fig. 5.
The inward or downward extension b of the tooth or cutter B is let, or inserted,
into the notch a of the disk A. and held therein by a rivet e swaged or hammered
in place, as well understood.
Each tooth or cutter B has one vertical edge or wall provided with a V-shaped
or other form of groove 63 and its other vertical wall or edge provided with a
correspondingly shaped ridge or rib 6 thus providing for the seating thereat into
each other of the entire, continuous series of cutters or teeth firmly or rigidly
interlocking the same into a solid body, greatly aiding their power of resistance
against displacement.
Each tooth, it will be observed, is provided with a flat or solid base at the
bottom of its vertical portion, as at 1, (Fig. 2) and with a corresponding base for
its horizontal portion, as at 2, (Fig. 4) and the plate or blade is provided with a
corresponding flat or solid seat in the bottom of each notch or socket, and a
similar seat upon the edge-portion of the plate or blade; intermediately of the
notches or sockets, as at 3 and 4, (Figs. 2 and 4) respectively. This provides for
the seating of the teeth squarely and solidly down upon the plate, and enables both
the teeth and plate to retain their full or maximum strength and efficiency, as well as
dispenses with a peculiar, or especially constructed, fastening for the retention of
the tooth in place, or its connection with the plate or blade, as distinguished from
the dovetailing, or tongue-and-groove, cam-and-plate, and splicing method of
connecting the tooth to the plate or blade, as heretofore practised. It will be also
seen that, by reason of my particular construction of tooth, the series are caused to
brace each other longitudinally, and also themselves to be braced by the shoulders
or abutments formed by the intermediate edge-portions of the plate or blade,
between the notches of sockets, as will be readily appreciated, and not required to
have their horizontal portions sunk into the edge of the plate or blade for the
purpose of resisting edge-wise thrust, as has previously been done.
Instead of grinding or concaving the disk A, which is done, as heretofore
practised, for the clearance of the kerf, I flare the teeth or cutters B from a point
touching the circle bounding the periphery of the disk A, outward to their outer
edges or points for that purpose, thus enabling me to make the disk or blade,
proper, of an equal thickness throughout, which allows of its being tensioned and
trued with the greatest accuracy.
Additional advantages of my invention are that the teeth or cutters can be
replaced, when required, entire, or in sections, and that the blade, proper, being of
even thickness, as previously stated, is enabled to stand a greater feed, consequently
do more work than circular saws of this class as heretofore constructed. It will
also be seen, as before stated, that the teeth or cutters can be made of a high
tempered tool-steel, while the body of the blade, or circular plate, proper, can be
made of regular saw-steel.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
In an insertible-toothed saw, the combination, with the plate or blade having the
tooth-receiving notches or sockets, each having a flat bottom or seat and the
intermediate edge-portions between said notches or sockets provided, each, with a
like seat, of the insertible teeth, each made with two substantially equal right-
angle portions, one of which is provided with a series of comparatively small
cutting points merging with the cutting points of the next tooth as arranged in
order, the lower or inner edges of the said right-angle portions being also produced
flat and fitting squarely down upon the aforesaid flat surfaces or seats of the plate
or blade, and the rivets or fastenings securing said teeth, at one edge, to said
plate or blade against outward displacement, said teeth also interlocking with said

page_text: plate or blade and each other at their respective adjoining edges, substantially as
and for the purpose set forth.
plate or blade and each other at their respective adjoining edges, substantially as
and for the purpose set forth.
this otse day
In testimony whereof I affix my signature in
presence of two witnesses.
In testimony whereof I affix my signature in
presence of two witnesses.
JOSHUA OLDHAM.
Witnesses :-
CHARLES F. AUKAMP.
GEORGE P. SANBORN.
Wheatley & Mackenzie,
40 Chancery Lane, London, Agents.
JOSHUA OLDHAM.
Witnesses:
CHARLES F. AUKAMP.
GEORGE P. SANBORN.
Wheatley & Mackenzie,
40 Chancery Lane, London, Agents.