AN IMPROVED CHUCK FOR HOLDING DRILLS AND OTHER TOOLS
Year: 1866

page_text: LETTERS PATENT to Charles Churchill, of Norwood, in the County of
Surrey, Merchant, for the Invention of "AN IMPROVED CHUCK FOR
HOLDING DRILLS AND OTHER TOOLS."-A communication from abroad by
Albert Beach, of Newark, New Jersey, United States of America.
Sealed the 16th April 1867, and dated the 7th November 1866.
PROVISIONAL SPECIFICATION left by the said Charles Churchill at the
Office of the Commissioners of Patents, with his Petition, on the 7th
November 1866.
I, CHARLES CHURCHILL, of Norwood, in the County of Surrey, Merchant,
do hereby declare the nature of the said Invention for "AN IMPROVED CHUCK
FOR HOLDING DRILLS AND OTHER TOOLS," a communication, to be as follows:-
The nature of the said Invention chiefly consists in producing a cheap and
efficient chuck for holding drills and other tools in a central position so con-
structed and arranged that the jaws can be forced simultaneously towards the
centre of the chuck to gripe the drill or other tool by simply turning the cap
employed in one direction, and the jaws can be drawn simultaneously from
the centre to liberate or receive the drill or other tool by simply turning the
cap in the opposite direction. The body of the chuck is of the ordinary con-
struction with the usual aperture at its rear end, so that it can be readily

page_text: secured to a mandril. The forward end is made cylindrical for a short
distance, say, about one-sixth of the length of the chuck, more or less, and
then conical for about one-third of the length, more or less, from which point
it continues cylindrical to the rear end, which cylindrical portion is of two
diameters; the rear portion extending about one-third the length of the chuck,
more or less, is of a diameter slightly larger, and in this part is formed a
thread. The body of the chuck has a central hole or aperture extending from
the front as far back as the rear end of the said conical part, or it may extend
entirely through the said body. There are three radial longitudinal slots or
grooves extending from the front end of this aperture as far back as the rear
end of the conical part of the chuck, the outer edges running parallel with
the exterior surface of the conical portion of the body, into each of which slots
a jaw is fitted to move radially therein. The inner edges of these jaws aro
formed as usual to gripe the shank of a drill or other tool that may be used,
and the outer edges are inclined to their inner edges at the same angle as the
said conical part of the chuck is inclined to the said central hole or aperture.
Each of said jaws is prevented sliding endwise by means of a screw which is
fitted in a radial hole made in the body of the chuck at the juncture of the
jaws; the hole for the cylindrical head of the screw extending slightly into the
side of the jaw. Around the body of the chuck is fitted a shell or cap, the
inside of which is fitted to turn and move longitudinally on the cylindrical
portion of the chuck, a thread being formed in the rear end to fit the thread
on the body of the chuck. Forward of the cylindrical part this cap is formed
in the shape of a hollow cone, the interior corresponding with the conical part
of the body of the chuck, and its aperture at the front end just fitting the
cylindrical front end of the said body. Each of said jaws is formed with a
tongue or hook extending back some distance from the front end of the
chuck over the outside of the said cap or shell; when the said cap is turned
in one direction it is caused to travel on the body of the chuck and towards
the rear end thereof, and in this movement its interior conical surface will act
on the outer inclined edge of the said jaws, thereby forcing them simul-
taneously inward to gripe and firmly hold a drill or other tool inserted in
the said central hole or aperture, and when the said cap is turned in an
opposite direction or unscrewed the exterior surface of its conical portion acts
against the said tongues of the jaws, by which means the said jaws are forced
radially and simultaneously outward, thereby releasing the drill or other tool
.inserted in the said central hole or aperture.
By the construction and arrangement above described a centering chuck is
obtained, the jaws of which without sliding endwise are moved inward and

page_text: outward by simply turning a cap on the body of the chuck, or the latter is
turned in the cap or shell, thereby avoiding the serious defect heretofore
experienced in chucks which have a longitudinal movement.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Churchill in the Great Seal Patent Office on the
6th May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
CHURCHILL, of Norwood, in the County of Surrey, Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of November, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles Churchill, Her special licence that I, the said Charles Churchill, my
executors, administrators, and assigns, or such others as I, the said Charles
Churchill, 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 "AN IMPROVED CHUCK POR
HOLDING DRILLS AND OTHER. TOOLS," (a communication,) upon the condition
(amongst others) that I, the said Charles Churchill, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands, and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be, per-
formed, and cause the same to be filed in the Great Seal Patent Off.ce
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE; that I, the said Charles Churchill, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Sheet of Drawings
forming a part of this Specification:
The nature of the said Invention chiefly consists in producing a cheap and
efficient chuck for holding drills and other tools in a central position so con-
structed and arranged that the jaws can be forced simultaneously towards the
centre of the chuck to gripe the drill or other tool by simply turning a cap

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is an exterior side view of my improved chuck; Figure 2 is a
front end view of the same; Figure 3 is a longitudinal section on the line x, x,
Figure 2; Figure 4 is a side view of the interior portion of the said chuck.
Like letters indicate the same parts in each of the Figures.
The body of the chuck A is of the ordinary construction with the usual
aperture at its rear end, so that it can be readily secured to a mandril. The
forward end a is made cylindrical for a short distance, say, about one-sixth of
the length of the chuck, more or less, and then conical for about one-third of
the lengtb, more or less, from which point it continues cylindrical to the rear
end a', which cylindrical portion is of two diameters; the rear portion, extending
about one-third of the length' of the chuck, more or less, is of a diameter
slightly larger, and on this part is formed a screw thread a'. The body of the
chuck has a central hole or aperture 6 extending from the front as far back
as the termination of the said conical part, or it may extend entirely through
the body A of the chuck. There are three radial longitudinal slots or grooves c
extending from the front end of this aperture as far back as the rear end of
the conical part of the chuck, the outer edges running parallel with the
exterior surface of the conical portion of the body A; into each of these slots ca
jaw d is fitted to move radially therein; the inner edges of these jaws are
formed as usual to gripe the shank of a drill or other tool that may be used,
and the outer edges are inclined to their inner edges at the same angle as the
said conical part of the chuck is inclined to the central hole or aperture 6.
Each of the jaws d is prevented sliding endwise by means of a screw e, which
is fitted in a radial hole made in the body of the chuck at the junction of the
jaws, the hole for the cylindrical bead of the screws e extending slightly into
the side of the jaws d.. Around the body A of the chuck is fitted a shell or
cap B, the inside of which is fitted to turn and move longitudinally on the
cylindrical portion of the body A, a thread being formed in the rear end to fit
the thread as on the latter. Forward of the cylindrical part this cap B is formed
in the shape of a hollow cone, its interior surface corresponding with the
conical part of the body A of the chuck, and its aperture at the front end just
fitting the cylindrical front end of the body A. Each of the jaws d is formed
with a tongue or hook d¹ extending back some distance from the front end of
the chuck over the outside of the cap or shell B. When the said cap is

page_text: turned in one direction it is caused to travel on the body A of the chuck and
towards the rear end thereof, and in this movement its interior conical surface
will act on the outer inclined edge of the jaws d, thereby forcing them simul-
taneously inward to gripe and firmly hold a drill or other tool inserted in the
central hole or aperture 6, and when the said cap is turned in the opposite
direction or unscrewed the exterior surface of the conical portion acts against
the tongues d' of the jaws d, by which means the said jaws are forced readily
and simultaneously outward, thereby releasing the drill or other tool inserted
in the central hole or aperture c. By the construction and arrangement above
described a centering chuck is obtained, the jaws of which without sliding
endwise are moved inward and outward by simply turning a cap on the body
of the chuck or by turning the latter in the cap, thereby avoiding the serious
defect heretofore experienced in chucks which have a longitudinal movement.
Having thus fully described the said Invention as communicated to me by
my foreign correspondent, and shewn how the same may be conveniently and
advantageously carried into practice, I claim a chuck consisting of the body A,
the cap B, and jaws d, constructed, combined, and operating substantially as
and for the purpose set forth.
In witness whereof, I, the said Charles Churchill, have hereunto set
my hand and seal, this Sixth day of May, in the year of our Lord
One thousand eight hundred and sixty-seven.
CHARLES CHURCHILL. (L.S.)
Witness,
GEORGE HASELTINE,
"International Patent Office,"
8, Southampton Buildings,
London, W.C.