CERTAIN IMPROVEMENTS IN GRINDING CIRCULAR SAWS
Year: 1858

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "CERTAIN IMPROVEMENTS IN GRINDING CIRCULAR SAWS."
-A communication.
Sealed the 5th October 1858, and dated the 8th May 1858.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, an the
8th May 1858:
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature.
of the said Invention for "CERTAIN IMPROVEMENTS IN GRINDING CIRCULAR SAWS,"
to be as follows:-
The object of this Invention of certain improvements in grinding circular
saws is to grind these articles to a uniform thickness, and with their faces
perfectly even, or free from the wavy appearance so frequently produced by
some of the methods of grinding heretofore practised, and to finish them
perfectly from the centre or eye.
One of the improvements consists in grinding one side of a saw at a time,
while its opposite side is supported by a roll which has a rotary motion at the
requisite speed for the purpose of causing the saw to rotate at the speed
desired.
Another improvement consists in the employment of a rotating friction
clamp, applied to the saw during the grinding process in such a manner that
it derives rotary motion from the saw through the agency of friction, and by
the momentum acquired by such rotary motion is caused to control and render

page_text: uniform, or nearly so, the velocity of rotation of the saw, notwithstanding any
differences of thickness of the saw plate, and consequent tendency to variation
in the action of the feed roll or other feeding contrivance upon the thicker and
thinner portions of the plate. The spindle which carries the saw is, together
with the friction clamp, mounted in a moveable or travelling frame, whereby
the saw may be moved up to the grinding surface as the grinding operation
proceeds.
The saw is also arranged to rotate in and during the grinding process upon
a flat pivot, which is of sufficient width in one direction to fill the eye of the
saw, and steady the saw as it rotates, and is thin enough in a transverse
direction to permit the grindstone to operate over the whole surface of the
saw.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office
on the 8th November 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of May, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Edward Newton, Her special license that I,
the said William Edward Newton, my executors, administrators, and assigns,
or such others as I, the said William Edward Newton; my executors,
administrators, and assigns; should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within.
the United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN GRINDING CIRCULAR
SAWS," being a communication from abroad, upon the condition (amongst
others) that I, the said William Edward Newton, by an instrument in
writing under my hand and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.

page_text: NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same
to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
The object of this Invention, as communicated to me by my foreign corre-
spondent, is to grind circular saws to a uniform thickness, and with their faces
perfectly even, or free from the wavy appearance so frequently produced by.
some of the methods of grinding heretofore practised, and to finish them
perfectly to the centre or eye.
The Invention consists in grinding one side of a saw at a time, while its
opposite side is supported by a roll, which has a rotary motion at the requisite
speed to cause the revolution of the saw as desired.
The Invention also consists in the employment of a rotating friction clamp,
applied to the saw during the grinding process in such manner that it derives
rotary motion from the saw through the agency of friction, and by the mo-
mentum acquired by such rotary motion, is caused to control and render
uniform, or nearly so, the velocity of rotation of the saw, notwithstanding any
differences of thickness of the saw plate, and consequent tendency to variation
in the action of the feed roll or other feeding contrivance upon the thicker and
thinner portions of the plate.
In the accompanying Drawing, Fig. 1 is a plan of a circular saw grinding
machine in which all the features of the Invention are employed; Fig. 2 is
a vertical section in the line x, x, of Fig. 1; and Fig. 3 is a vertical section
in the line y, y, of Fig. 1. Similar letters of reference indicate corresponding
parts in the several Figures. A is the main framing of the machine, on
which are the bearings for the shaft B of the grindstone C, and for the shaft
D of the roll E, which supports the saw against the stone. The shafts B and
D are arranged horizontally and parallel to each other, and the stone and
roll are about the same width across the peripheries, which are arranged
opposite each other, and at a sufficient distance apart to admit the saw
between them, such distance being adjusted by two screws a, a, which are
applied to the journal boxes b, b, of the grindstone shaft, and which are
operated simultaneously by, turning a small spindle c, which works in fixed
bearings, and carries two endless screws d, d, which gear with worm wheels
e, e, on the heads of the screws a, a. The grindstone is driven by a belt
running over a pulley F on its shaft, and the roll E is driven at a much less
velocity than the grindstone, and in an opposite direction, by its shaft being
geared by spur gearing f, g, with a shaft h, which is driven by a belt running

page_text: to its pulley i. The grindstone and roll rotate in opposite directions as shown
by arrows in Fig. 2. I is a frame secured to the main framing A, to support
the saw carriage G, which is fitted to slide in a direction parallel with the
shafts B, D, in ways j, j, in the said frame. The saw carriage consists simply
of a plate of cast iron, carrying at its inner end the flat thin pivot k, upon
which the saw rotates, which pivot is parallel with the plane of revolution of
the stone; the width of this pin, taken in a vertical direction or parallel to the
plane of revolution of the stone is equal to that of the diameter of the eye of the
saw, but its thickness in a direction perpendicular to the aforesaid plane of revo-
lution is trifling, as shown in Fig. 3, to permit the stone to grind to the eye of
the saw. The said pivot may be attached in the saw carriage in various ways, to
permit of its easy removal for the purpose of placing the saws in and removing
them from the carriage; but it is represented as being furnished at its ends with
flat lugs k', k, which are attached to the carriage by screws 1, 1, passing through
them and screwing into the carriage. H is the saw, which is free to move
along the pivot k, that it may be permitted to find its proper position. On the
rear portion of the carriage there is a rack r, with which is geared a pinion s
on a shaft t, working in bearings in the frame I. The shaft t can be turned.
by a hand wheel u on one end of it, for the purpose of moving the carriage.
The saw carriage G also carries the rotating friction clamp, which is
composed of two rings m, m, of stout steel plate of about one foot in diameter
externally, and about nine inches internally, attached to a shaft p, each by
means of a series of arms n, n, made of a single piece of lighter steel plate.
than that of which the rings are composed. The rings and arms of the clamps
are all tempered to a high spring temper, and the arms are so set as to press
the rings towards each other with considerable force. The rings m, m, are
bevelled from their peripheries towards their inner faces, as shewn in Figs. 1.
and 2, to permit the saws to enter easily between them. The plates con-
stituting the arms n, n, are secured to the shaft p by three nuts v, v, v, which
fit to a screw thread on the shaft, and clamp the said plates between them.
The bearings w, w, in which the clamp shaft p works, are secured firmly to
the saw carriage by screws z, z, and nuts 2, 21, which pass through slots 22, 22,
in the carriage, and thus permit the adjustment of the clamp shaft nearer to
or further from the saw pivot k. These bearings w, w, are made large enough
to give the shaft considerable play towards and from the saw, and the shaft is
made without shoulders to its journals, that it may be free to move endwise in
its bearings. The clamp shaft is furnished with a fly wheel p' at each end.
The operation of grinding in the machine is as follows:-The saw to be
ground having been placed on the pivot k, and the pivot placed in the carriage,

page_text: with the saw between the rings of the clamp, the carriage is run up towards
the grindstone to bring the saw between it and the roll E, and the grindstone is
adjusted by the screws a, a, to the proper distance from C; the grindstone and
the roll E are then set in motion. The roll holds the saw flat up to the stone,
and prevents it assuming a dishing form or being ground to a wavy surface.
The high velocity of the grindstone tends to rotate the saw rapidly, but this
is nearly counteracted by the roll E, to the speed of which, or thereabouts, the
velocity of the rotation of the saw is reduced by the friction of the clamp rings
m, m. The clamp derives a rotary motion from the saw by the friction
produced between them, and by aid of its fly wheels it is caused to acquire
such a movement as will serve to counteract any tendency to variation in the
speed of the saw, which, if not of uniform thickness, wonld have a tendency
to rotate faster when the thicker portions and slower when the thinner portions
were passing between the stone and the roll, which variation, if not counter-
acted, would cause the saw to be ground most in the thinnest places, and
least in the thickest ones; but the clamp, by holding it back when it tends to
run away with the stone, and by helping it forward when it tends to move too
slowly, causes it to be ground to a uniform thickness. The saw carriage is
moved up gradually or at regular intervals by the rack and pinion.
Having now set. forth the nature of the Invention of improvements in
grinding circular saws, as communicated to me by my foreign correspondent, and
explained the manner of carrying the same into effect, I wish it to be under-
stood that I do not claim the means whereby the grindstone is permitted to
work up to the eye of the saw, as described; but what I claim under the
above in part recited Letters Patent is, the employment of the roll E in
combination with the rotating friction clamp for imparting the requisite
rotary motion to the saw when under the action of the grindstone for the
purpose herein described.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Eighth day of November, in the year of
our Lord One thousand eight hundred and fifty-eight.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)