IMPROVED SELF-CENTERING AND TIGHTENING CHUCKS FOR DRILLING MACHINES, LATHES, AND OTHER MACHINES IN WHICH CHUCKS ARE USED
Year: 1865

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes
and Son, Patent Agents, 123, Chancery Lane, London, for the Invention
of "IMPROVED SELF-CENTERING AND TIGHTENING CHUCKS FOR DRILLING
MACHINES, LATHES, AND OTHER MACHINES IN WHICH CHUCKS ARE USED."―
A communication from abroad by John Edwin Earle, of New Haven,
PROVISIONAL SPECIFICATION left by the said Edward Thomas Hughes
at the Office of the Commissioners of Patents, with his Petition, on the
28th September 1865.
I, EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, Patent
Agents, 123, Chancery Lane, London, do hereby declare the nature of the
said Invention for "IMPROVED SELF-CENTERING AND TIGHTENING CHUCKS FOR
DRILLING MACHINES, LATHES, AND OTHER MACHINES IN WHICH CHUCKS ARE USED,"
a communication to me from abroad by John Edwin Earle, of New Haven,
State of Connecticut, United States of America, to be as follows:-
The principal feature of this Invention relates to that class of chucks called
universal, in which the tool or other article to be held is griped between

page_text: two, three, or more jaws, to which simultaneous movements in and out and
to and from the axis of the chuck may be given by the turning of a shell,
ring, plate, or other moveable part, the axis of motion of which is in the axis
of the chuck; as examples of which class may be mentioned drill chucks of
A serious
the ordinary form, and the common well-known scroll chuck.
difficulty experienced in the use of the ordinary forms of chucks aforesaid is
that by undue or irregular twisting strains the article held is liable to become
loosened in the gripe of the jaws, and is insufficiently held.
It is the object of the leading feature of the Invention aforesaid to over-
come this objection, and to this end the said leading feature consists in so
connecting the moveable jaws with that part of the chuck by the turning of
which the movements of the jaws are produced, that a tendency to twist any
article held in the jaws will tend also to turn the said part of the chuck by
which the jaws are closed, and thereby cause the said jaws to grasp the
article tighter and prevent its displacement, substantially as herein-after
clearly set forth.
The remaining feature of the Invention consists in a peculiar construction
and combination of certain parts of a self-centering chuck substantially as
berein-after clearly described and specified, whereby more accurate positive
movements are given to the jaws, both in opening and closing, than in chucks
of the usual construction.
To enable others to make and use this Invention, I will proceed to give a
description thereof in its application to a chuck, which, made in the pro-
portions indicated, is particularly adapted for holding drills, reamers, taps,
and similar tools, or for holding small articles to be turned or drilled in a
lathe.
In the accompanying Sheet of Drawings, Fig. 1 is a section through the
axis of a chuck in which the Invention is embodied; Fig. 2 a side elevation
of the same with the cap D and jaws C removed; Fig. 3 shows an end view
of the chuck; Fig. 4 a cross section at X, X, Fig. 1; and Fig. 5 an end
view of the parts represented in Fig. 2.
A is a cylindrical hub, the rear end of which is bored out to fit on the end
of a tapering plug, which may be inserted in the spindle of a lathe or drilling
machine, or the hub may be secured to the spindle in any other suitable
way, and which will ensure the accurate coincidence of its axis with that of
the spindle. The hub A has a spiral thread or male screw formed upon its
rear part, the front part being straight and truly cylindrical, to serve in con-
nection with the threaded part as an accurate guide for the shell B, which
fits the said hub, and has at its rear end an internal screw thread which fits

page_text: the male thread on A. The front part of the shell B is of conical form, and cut
through in three places to form parallel-sided guideways for the three jaws C.
These guideways point to the axis of the chuck, and are made wide at the
periphery of the cone, which wider parts form recesses in the conical surface
(as shown in the Drawings). The bottoms of these recesses are parallel
with the adjacent conical surface. The jaws C have parallel sides, and are
provided on the back or outer edges with wings or shoulders which fit the
wide parts or recesses of the guideways. These jaws are so shaped that when
inserted from the outside in to the guideways their outer edges slant so as to
correspond with and be even with the conical surface of B, while their inner
edges are parallel with the axis of the chuck. D is a conical cap, the
internal surface of which corresponds to and fits the conical part of the shell B
to which it is sccured by a screw thread, as shewn in Fig. 1.
This cap
confines the jaws in their guideways in such a way that when the shell B,.
with the cap D secured thereon, is moved longitudinally forward and back
relatively to the jaws C the latter are opened and closed to and from the
axis of the chuck with positive movements, their inner edges constantly main-
taining parallelism with the said axis. The jaws.C are provided with deep
notches & which catch on to a dise or collar e secured to and projecting from
the front part of the bub A; these prevent any longitudinal movement of the
jaws. When the chuck is to be used in a lathe of ordinary construction, or
in a drill press the spindles of which turn in the usual direction, the screw
thread upon
A should be made "right-handed;" but if it be required to use the
chuck with a spindle having a left-banded or backward movement of revolution
suitable for left-hand drills, then the screw or hub should have a left-hand
thread.
The chuck shown in the Drawings is of the former description, and I will
now proceed to describe its operation and use.
The jaws are opened by turning the shell B backward, and thus unscrewing
it on the hub A. The drill or other article to be held in the chuck is
inserted between the jaws, and the shell B is grasped by the hand or with a
wrench and is turned to the right or forward, which screws it further on to
the hub A, whereby the said shell is forced further on to the jaws C, seen in
red, Fig. 1, and these are thereby, in the manner already described, caused
to close and gripe the article between them, holding it truly in coincidence
with the axis of the chuck. When a drill thus held is at work the resistance
to its cutting will tend to cause it to turn within the grasp of the jaws, but
this will be prevented by the resulting tendency to turn the shell B (which
contains the jaws) relatively to the hub A, whereby the shell would be screwed

page_text: further on to the hub, and thereby increase the gripe of the jaws upon the
drill. The same result occurs when the chuck is used to hold any article to
be turned or bored in a lathe, the resistance of the cutting tool occasioning a
tightness of the hold of the jaws on the work.
The advantages of constructing the recessed guideways in the shell B, as
described, and the use of the conical cap D therewith, are that the jaws
may thereby be forcibly pulled upon as well as forced together, thus.
obviating the objectionable use of springs to throw out the jaws. The jaws
are thus accurately guided, and their exact centering secured in all positions.
The construction of the instrument is simple.
Although this Invention has been represented in its application to a chuck
for small work, yet it is obvious that by altering its proportions it may be
adaptefor more general use.
And although I have described the leading feature of the Invention as
applied to the chuck herein-before particularly described (wherein the jaws
are closed by a conical surface), yet this application of the said feature
may with advantage be applied to many forms of chucks which otherwise
may differ from the one represented in the Drawings and above referred to.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Thomas Hughes in the Great Seal Patent Office
on the 28th March 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents, 125,
Chancery Lane, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of September, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edward Thomas Hughes, Her special licence that I, the said Edward
Thomas Hughes, my executors, administrators, and assigns, or such others as
I, the said Edward Thomas Hughes, 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
"IMPROVED SELF-CENTERING AND TIGHTENING CHUCKS FOR DRILLING MACHINES,

page_text: LATHES, AND OTHER MACHINES IN WHICH CHUCKS ARE USED," a communication to
me from abroad by John Edwin Earle, of New Haven, State of Connecticut,
United States of America, upon the condition (amongst others) that I, the said
Edward Thomas Hughes, my executors or administrators, by an instrument in
writing under my, or their, or one of their bands and seals, 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.
NOW KNOW YE, that I, the said Edward Thomas Hughes, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say):-
The principal feature of this Invention relates to that class of chucks
called "universal," in which the tool or other article to be held is griped
between two, three, or more jaws, to which simultaneous movements in
and out, and to and from the axis of the chuck may be given by the turning
of a shell, ring, plate, or other moveable part, the axis of motion of which is
in the axis of the chuck, as examples of which class may be mentioned drill
chucks of the ordinary form, and the common well-known scroll chuck. A
scrious difficulty experienced in the use of the ordinary forms of chucks
aforesaid is, that by undue or irregular twisting strains the article held
is liable to become loosened in the gripe of the jaws, and is insufficiently
held.
It is the object of the leading feature of the Invention aforesaid to over-
come this objection, and to this end the said leading feature consists in so
connecting the moveable jaws with that part of the chuck, by the turning
of which the movements of the jaws are produced, that a tendency to twist
any article held in the jaws will tend also to turn the said part of the chuck
by which the jaws are closed, and thereby cause the said jaws to grasp the
article tighter and prevent its displacement, substantially as herein-after
clearly set forth.
The remaining feature of the Invention consists in a peculiar construction
and combination of certain parts of a self-centering chuck substantially as
berein-after clearly described and specified, whereby more accurate positive
movements are given to the jaws, both in opening and closing, than in chucks
of the usual construction.
:
To enable others to make and use this Invention, I will proceed to give a
description thereof in its application to a chuck, which, made in the propor-
:

page_text: tions indicated is particularly adapted for holding drills, reamers, taps, or small
articles to be turned or drilled in a lathe.
In the accompanying Sheet of Drawings, Fig. 1 is a section through the
axis of a chuck in which the Invention is embodied, and Fig. 2 a side eleva-
tion of the same with the cap D and jaws C removed; Fig. 3 shows an end
view of the chuck; Fig. 4 a cross section at X, X, Fig. 1; and Fig. 5 an
end view of the parts represented in Fig. 2.
A is a cylindrical hub, the rear end of which is bored out to fit on the end
of a tapering plug, which may be inserted in the spindle of a lathe or drilling
machine, or the hub may be secured to the spindle in any other suitable
way, which will insure the accurate coincidence of its axis with that of the
spindle. The hub A has a spiral thread or male screw formed upon its rear
part, the front part being straight and truly cylindrical, to serve in connection
with the threaded part as an accurate guide for the shell B, which fits the
said hub, and has at its rear end an internal screw thread which fits the male
thread on A. The front part of the shell B is of conical form, and cut
through in three places to form parallel-sided guideways for the three jaws C.
These guideways point to the axis of the chuck, and are made wide at the
periphery of the cone, which wider parts form recesses in the conical surface
(ás shown in the Drawings.) The bottoms of these recesses are parallel with
the adjacent conical surface. The jaws C have parallel sides, and are pro-
vided on the back or outer edges with wings or shoulders which fit the wide
parts or recesses of the guideways. These jaws are so shaped that when
inserted from the outside into the guideways their outer edges slant so as to
correspond with and be even with the conical surface of B, while their inner
edges are parallel with the axis of the chuck. D is a conical cap, the internal
surface of which corresponds to and fits the conical part of B, to which it is
secured by a screw thread, as shown in Fig. 1. This cap confines the jaws in
their guideways in such a way that when the shell B, with the cap D secured
thereon is moved longitudinally forward and back, relatively to the jaws C,
the latter are opened and closed to and from the axis of the chuck with
positive movements, their inner edges constantly maintaining parallelism with
the said axis. The jaws C are provided with deep notches d, which catch on
to a disc or collar e, secured to and projecting from the front part of the
hub A; these prevent any longitudinal movement of the jaws. When tho
chuck is to be used in a lathe of ordinary construction, or in a drill press,
the spindles of which turn in the usual direction, the screw thread upon A
should be made "right handed; but if it be required to use the chuck
with a spindle having a "left handed" or backward movement of revolution,

page_text: suitable for left-hand drills, then the screw, or hub should have a left-hand
thread.
The chuck shown in the Drawings is of the former. description, and I will
now proceed to describe its operation, and use. The jaws are opened by
turning the shell B backward, and thus unscrewing it on the hub A; the drill
or other article to be held in the chuck is inserted between the jaws, and the
shell B is grasped by the hand or with a wrench and turned to the right or
forward, which screws it further on to the hub A, whereby the said shell is
forced further on to the jaws C, as seen in red, Fig. 1, and these are thereby,
in the manner already described, caused to close and gripe the article between
them, holding it truly in coincidence with the axis of tho chuck. When a
drill thus held is at work the resistance to its cutting will tend to cause it to
turn within the grasp of the jaws, but this will be prevented by the resulting
tendency to turn the shell B (which contains the jaws) relatively to the hub A,
whereby the shell would be screwed further on to the hub, and thereby increase
the gripe of the jaws upon the drill. The same result occurs when the chuck
is used to hold any article to be turned or bored in a lathe, the resistance
of the cutting tool occasioning a tightening of the hold of the jaws on the
work.
The advantages of constructing the recessed guideways in the shell B, as
described, and the use of the conical cap D therewith, are that the jaws may
thereby be forcibly pulled upon as well as forced together, thus obviating the
objectionable use of springs to throw out the jaws; the jaws are thus
accurately guided, and their exact centering secured in all positions, and the
construction of the instrument is simple.
Although I have represented this Invention in its application to a chuck
for small work, yet it is obvious that by altering its proportions it may be
adapted for more general use. And although I have described the leading
feature of the Invention as applied to the chuck herein-before particularly
described (wherein the jaws are closed by a conical surface), yet this applica-
tion of the said feature may with advantage be applied to many forms of
chucks which otherwise may differ from the one represented in the Drawings
and above referred to.
Having thus fully described the nature and particulars of the said Invention,
as communicated to me, I claim,-
Firstly, forming the guides for the sliding jaws in that part of the chuck by
the turning of which the closing of the jaws is effected, substantially in the
manner herein set forth.

page_text: Secondly, the inclined converging guideways c in combination with the
jaws C, head D, and screw spindle A, constructed and operating in the manner
and for the purposes substantially as herein shown and described.
In witness whereof, I, the said Edward Thomas Hughes, have hereunto
set my hand and seal, this Twenty-seventh day of March, in the year 5
of our Lord One thousand eight hundred and sixty-six.
E. T. HUGHES. (L.S.)