Improvements in Saws for Cutting Metal and other Substances, and in the Method and Apparatus Employed in the Manu- facture of the same.
Year: 1885

page_text: Improvements in Saws for Cutting Metal and other Substances,
and in the Method and Apparatus Employed in the Manu-
facture of the same.
I THADDEUS FOWLER of New Haven, Connecticut one of the United States
of America, Machinist do hereby declare the nature of my invention for
IMPROVEMENTS IN SAWS FOR CUTTING METAL AND OTHER SUBSTANCES AND IN
THE METHOD AND APPARATUS EMPLOYED IN THE MANUFACTURE OF THE SAME
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 saws, more especially of that class used in cutting
metal and other hard substances, and has for its object to furnish a saw which,
while hard as to its teeth, so as to insure a durable cutting edge, shall be of such
temper, as to its body, as to prevent the latter from breaking when subjected to
sudden cross strain or twist.
The invention consists in the manufacture of a new article of manufacture,
consisting of a saw blade made from tough pliable steel, and having its teeth
hardened to a high temper down to or near their base line or the line of juncture
of the teeth with the body of the blade, leaving the body and back of the blade
softer than the teeth.
-
The invention also consists in a saw composed of a band or strip of metal having
a soft back, and high tempered or hardened teeth.
And also in the method and apparatus for manufacturing the same.
Figure 1 of the drawing represents a saw embodying my invention.
Figure 2 a top view of an apparatus for tempering the same, and
Figure 3 a section of Figure 2 in the line X-X.
Referring to the drawing A represents a strip or band of steel having at one
edge a series of teeth B, cut therein in any usual way common to the production
of saws of the class known as band or hack saws, billet, webs, and meat saws.
The strip or band having been provided with teeth is led into a furnace or other
suitable heating apparatus, where it is heated to tempering heat, and from the said
furnace or apparatus the toothed blade or band is passed through a tempering
apparatus one form of which is represented in Figures 2 and 3, the toothed edge

page_text: only of the said band being acted upon by the tempering fluid, preferably water,
the tempering fluid, being prevented from rising or passing up upon the surface of
the band or saw beyond the roots of the teeth.
Preventing the tempering fluid from acting except upon the toothed part of band,
or saw, confines the hardening of the saw substantially to its toothed portion leaving
the undertoothed edge of the blade or saw and the main part of its body soft or
untempered.
The apparatus as herein shown to temper the toothed band or saw consists of a
box C, having a trough D, shown as curved at its under side; and provided with
openings 2 for the passage from the box C into the trough of the tempering fluid
employed, which is made to pass through the box C continuously, thus keeping the
water at the required temperature.
The box C at its upper side is provided with plates E, E¹, the latter being made
adjustable by means of adjusting screws F in slots in the said plate.
The edges of the plates E, E, are provided with a packing a, a, preferably of
asbestos or other equivalent material, because of its heat and fire resisting proper-
ties, the pressure of the packing against the sides of the blade or saw above its
toothed edge being sufficient to prevent the tempering fluid rising upon the said
blade or band above the roots of the teeth.
I do not desire to limit my invention to the use of the particular tempering
mechanism shown.
The apparatus described will in practice have applied to it a suitable gauge to
regulate the point to which the toothed edge of the plate may descend.
I may place in the trough an endless band of woven textile material and keep
the same moving slowly by means of a pair of feed rollers.
The water or tempering fluid in the box will in such case be just sufficient to
keep the said band saturated, and the teeth, by their contact with the wet textile
band, will be tempered or hardened but the temper will not extend into the body
and back of the said blade.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that
what I claim is
1. The manufacture and use of a saw composed of a tough pliable steel band or
strip having its teeth hardened to a high temper down to or near their base line
or the line of juncture of the teeth with the body of the plate, having the body and
back of the blade softer, substantially as described.
2. The method of manufacturing a saw composed of a strip or band of metal
toothed at one edge, the back or untoothed part of the saw being left soft or
untempered, the teeth being hardened or tempered, substantially as described.
3. The method of and apparatus for producing saws composed of a tough pliable
steel band or strip having its teeth hardened to a high temper down to or near
their base line or the line of juncture of the teeth with the body of the plate,
having the body and back of the blade softer substantially as set forth.
19th
Dated thin 10th day of October 1982
WM BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the said Thaddeus Fowler.