IMPROVEMENTS IN CIRCULAR SAWS, COMMONLY CALLED DRUNKEN SAWS
Year: 1865

page_text: LETTERS PATENT to William Tighe Hamilton, of Upper Rathmines;.
Dublin, in the Kingdom of Ireland, Barrister-at-Law, for the Invention.
PROVISIONAL SPECIFICATION left by the said William Tighe Hamilton
at the Office of the Commissioners of Patents, with bis Petition, on
the 29th May 1865.
I, WILLIAM TIGHE HAMILTON, of Upper Rathmines, Dublin, in the
Kingdom of Ireland, Barrister-at-Law, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN CIRCULAR SAWS, COMMONLY CALLED DRUNKEN
SAWS," to be as follows:-
My Invention consists in a method of mounting "drunken saws" upon
their spindles, whereby the said saws are caused to maintain a central position
at whatever angle they may be placed; this I accomplish by causing the
saw to turn upon a centre of motion at the same time that it is swivelled..
In an arrangement I propose for carrying out my Invention the saw is
held between two plates which are capable of swivelling upon the spindle ;
these plates are provided with curved lugs projecting into recesses formed in
a flange attached to the spindle. When the saw is angled these lugs turn in
the recesses and keep it in a central position, after which the whole is held
together by a binding nut or similar ordinary means.
According to another method of carrying out my Invention, and upon the

page_text: same principle of causing the saw to turn upon a centre of motion at the
same time that it is swivelled, I mount the saw upon the spindle with a "ball-
and-socket joint, and I adapt set screws or other ordinary fixing apparatus
to retain it at any desired angle
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Tighe Hamilton in the Great Seal Patent Office on
the 29th November 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
TIGHE HAMILTON, of Upper Rathmines, Dublin, in the Kingdom of Ireland,
Barrister-at-Law, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of May, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Tighe Hamilton, Her special license that I, the said William Tighe
Hamilton, my executors, administrators, and assigns, or such others as I, the
said William Tighe Hamilton, 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
"IMPROVEMENTS IN CIRCULAR SAWS, COMMONLY CALLED DRUNKEN SAWS,"
upon the
condition (amongst others) that I, the said William Tighe Hamilton, 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 Patént.
NOW KNOW YE, that I, the said William Tighe Hamilton, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by 'the
following statement and accompanying Drawings (that is to say) :-
My Invention consists in a method of mounting "drunken saws" upon
their spindles, whereby the said saws are caused to maintain a central position
at whatever angle they are placed; this I accomplish by causing the saw to
turn upon a centre of motion at the same time that it is swivelled.

page_text: In the accompanying Drawings, Figs. 1, 2, 3, 4, and 5 represent the method
I adopt for carrying out the above-mentioned principle of my Invention,
similar letters of reference on the several Figs. pointing out the same parts.
A portion of the saw spindle is shown at a to be mounted in the machine
after any usual manner, and upon it is formed a flange b; at c is another
flange loose upon the surface of the spindle, and capable of being forced
forward or allowed to move backward by a nut d bearing against it and
mounted on a screw thread cut upon the spindle. The saw is shewn at e held
between plates f, f, and prevented from turning loosely between them by means
of the ordinary pin. Each of the plates f is provided with two flanges g,
forming portions of circles, the centres of such circles being points upon a line
drawn at right angles to the axis of the spindle a. The plates are shewn
detached in two views at Figs. 4 and 5, and each of them is provided with a
central aperture h somewhat larger than the spindle which passes through
them, the aperture in the saw being of a similar diameter. The circular
flanges g are placed within recesses i formed in the bosses b, c, such recesses
being so formed as to correspond to the curves of the said flanges g. In
adjusting the saw for work the nut d is turned back so as slightly to liberate
the boss c, and the saw may then be swivelled to the desired angle, the
openings formed in the plates f admitting of that movement. During this
swivelling the flanges 9 will move in the recesses i, and as the curved surfaces
are struck from the points above mentioned the saw while it is adjusted to
the required angle will turn upon a centre which will maintain its true
position in reference to the spindle; when this has been accomplished the
nut d is turned so as to bind the flanges g between the bosses b, c, and the
saw will be in working order.
pro-
Figs. 6, 7, and 8 shew a modification of the above-described arrangement.
The saw e is confined as before between the two plates f, but in this instance
each of the said plates is mounted within the bosses b, c, by means of
jecting parts & situate coincident with the centre of the spindle a. The
surfaces of these projecting parts are struck from a centre, as before described,
but each guide consists of two detached portions in order to allow the spindle
to pass a detached view of the two plates f, and their projecting parts k is
shewn at Fig. 8. The saw is loosened for adjustment and subsequently
tightened by the nut d, as in the formerly described arrangement. Instead
of the above-described arrangements the flanges might be replaced by a ball
fitting into sockets formed in the bosses b, c, thus constituting a ball-and-
socket joint.
Having thus described and ascertained the nature of my said Invention,

page_text: and the manner in which the same is to be performed, I desire it to be
understood that I claim, as secured to me under the above in part recited
Letters Patent, the use of a guide or guides which cause the saw to turn upon
a centre of motion at the same time that it is swivelled.
In witness' whereof, I, the said William Tighe Hamilton, have hereunto
set my hand and seal, this Twenty-second day of November, in the year
of our Lord One thousand eight hundred and sixty-five.
WILLIAM TIGHE HAMILTON. (L.S.)