Improvements in Chucks or Tool-holders.
Year: 1891

page_text: Date of Application, 25th Aug., 1891-Accepted, 24th Oct., 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by WILLIAM SCHWANHAUSSER, Mechanical
Engineer, of No. 461, Eighth Street, Brooklyn, in the State of New York,
United States of America.]
Improvements in Chucks or Tool-holders.
I, HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Patent Agent, do hereby declare the
nature of this invention 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 chucks, and has especial reference to drill chucks, and
others of the class used in machines for boring, tapping, stud setting, and similar
purposes. In machines of this character, the chuck holding the drill, tap, and stud
setting device, is rigidly fastened to the driving spindle, and in consequence, when
employed for tapping, it becomes necessary, as the tap approaches the bottom of
the hole, to so regulate the stopping of the machine as to prevent the tap from
striking the bottom, and receiving the full power transmitted through the spindle,
which would result in the breaking of the tap, or if the tap is of sufficient strength
to resist the power, would injure the driving mechanism of the machine, or the
material on which the work is being done. When employed for stud setting, in
which operation it becomes absolutely necessary to provide a positive stop, in order
to gauge the proper projection of the stud, the same nicety of regulation as to the
stopping of the machine must be observed, thus requiring in either operation a
large amount of skill in the use of such machines when employed for these purposes.
Notwithstanding the greatest care, it is found, in practice, that many tools are
broken, or the machine, or material, injured, through the impossibility of judging
accurately the point at which it is necessary to stop the machine.
One object of this invention is, to obviate this difficulty by providing a simple,
cheap, and durable chuck, which shall be of sufficient rigidity to transmit or sustain
the force required for the performance of the work, but shall yield under an excess
of strain, permitting the tool to be driven at full speed until the completion of the
work, thus reducing greatly the amount of skill required, and preventing absolutely
the breaking of tools, or the injuring of either the machine or material.
In machines of this character, moreover, it is usual to employ a feeding device
constructed to be thrown out of operation when desired, the purpose of this being
to enable the machine to be used with either a drill, in the use of which a feeding
mechanism is required, or with a tap or other tool which itself forms a feeder. In
the latter case, the feed of the tool may, and frequently will, differ from that of the
feeding mechanism, the same machine being used with taps, the threads of which
are of different pitches. In such case, if the feeding mechanism is not thrown out
of operation in changing from drilling to tapping, or other similar work, either the.
tool, material operated upon, or the machine, will be broken.
Another object of the invention is to provide a chuck or other holder having tool-
holding means so constructed as to yield under a force tending to move the tool and
holder in different directions, and allow the tool to be drawn out, thus avoiding all
danger of breakage, in case the operator neglects to throw out the feeding
mechanism, in using a tap or other tool having a feed varying from that of the
feeding mechanism.
While it is evident that a chuck so constructed is of universal application in
machines of this character, it may be best illustrated by its use in a combined
drilling, tapping, and stud-setting machine, for which it is especially intended, and
will be shewn as thus applied.

page_text: In the accompanying drawings, forming a part of this Specification :
Figure 1 is a view, partly in section, shewing the improved chuck attached to a
drill spindle, and carrying a drill.'
Figures 2 and 3 are similar views, shewing the chuck in use with a tap, and in
stud setting.
A is a drill spindle or driver to which the chuck B is attached by its shank 1.
The chuck B consists of the body 2, screw-threaded upon the outside, and recessed
to receive the socket-piece 3, to which the tool or tool holder is to be attached.
The socket-piece 3 is formed with a neck 14, reduced in size, thus providing
shoulders 15 upon the base of the socket piece. Surrounding the threaded body 2
and the socket piece 3, is the screw cap 5, through which is passed the neck of the
socket piece, the cap thus bearing upon the shoulders 15. The body 2 and socket
piece 3, and the shoulders 15 and cap 5, may be in direct contact, but I prefer to
insert between their bearing surfaces, friction pieces 4, formed preferably of
vulcanised fibre, thus permitting the chuck to be made of ordinary material, and
enabling it to be used a long time, by renewal of the friction pieces or discs as
they wear. The cap 5 serves to adjust the friction between the parts, the friction
being increased as the cap is screwed farther up upon the body, pressing the body
and socket piece together. A locking nut 6 is provided for securing the parts in
position when adjusted.
The operation of this part of the device is as follows:-The tool or tool holder
having been inserted into the socket-piece 3, and attached thereto by means which,
so far as the operation of this part of the invention is concerned, may be of any
ordinary form, the friction of the parts is adjusted in accordance with the work to
be performed, by the screw cap 5, which is then locked in position by the locking
nut 6. The machine then being set in operation, the tool is driven by force trans-
mitted through the parts in frictional contact, until the work is complete.
In the operation of drilling, as the tool is driven through the material, the
cutting edges of the drill will catch upon the side of the opening formed, thus
tending to break the edges of the drill, or to injure the material.-In the case of
a tap, the completion of the work produces an increased strain, through the tap
reaching the limit of its motion in material G, and in the case of the stud-setting
device shewn in Figure 3, in which the block F limits the motion of the stud
holder D and stud E, a positive stop is reached. In each of the three cases, the
strain put upon the tool or holder is in excess of the rigidity of the chuck, and the
body 2 and cap 5 will turn upon the socket piece 3 which carries the tool or tool
holder, thus preventing any injury of the tool or material through the increased
strain. This movement of the body and cap independent of the tool, will indicate
the completion of the work, when the machine will be reversed. It is evident that
the close attention necessary in the use of a chuck of ordinary form is not required,
as the machine is driven at full speed until the parts of the chuck slip, and this
slipping is sufficient to call the attention of the operator without constant watching
of this part of the machine.
It will be understood that the feeding mechanism may be applied to either the
tool driver, or to the part carrying the material, the operation of the chuck being
the same, whether the tool moves toward the work, or vice versa, and whether the
tool be rotated, or the material rotated in contact with it. The chuck, moreover,
may be used to carry the material instead of the tool.
Referring now to the second part of the invention, the socket piece 3 is provided
with a spring catch 10, formed preferably of a pin having a rounded or beveled
end, as shewn, and the tool holder with a recess 9, in which the spring catch 10 is
adapted to enter, the recess also being formed preferably with rounded or bevelled
sides. The tool holder and socket piece may be connected by a spline 8, preventing
rotary movement of the parts upon each other, or if the parts be angular in cross
section, the spline will be unnecessary. The tool holder is inserted and secured in
the socket by simply sliding it into place, the catch 10 yielding to allow this,
but springing into the recess 9, as the base of the tool holder reaches and rests

page_text: upon the base of socket piece. The spring is made of sufficient rigidity so that
the catch holds the parts together in the ordinary operation of the machine, there
being, as is evident, no pressure tending to force the catch out, except the weight
of the tool and tool holder.
The operation of this part ofthe device is as follows:-If the feeding mechanism
used in connection with the drill shewn in Figure 1, be not thrown out of operation
in using the tap or setting the stud, as in Figures 2 and 3, and the feeding of
the tap or stud and that of the feeding mechanism be different, the pull tending
to separate the parts B and C will be sufficient, by the pressure on the rounded
or beveled sides, to force the spring catch 10 out of the groove or recess in the
chuck, thus permitting the latter to slide out of the chuck, and preventing any
injury to the parts. It is evident that either the catch or recess may be formed
with square sides, if desired, but the construction shewn is preferable. If the
catch be formed with square sides, the inner end of the tool or tool holder should
be beveled opposite the catch, as shewn on the inner end of tool holder C.
In Figure 2, the tap D, and in Fig. 3, the stud holder D, are shewn as connected
to their respective holders by means similar to that used in the chuck, consisting
of the spline 11, recess 12, and spring catch 13. This second attachment may be
of any ordinary form, so far as the special function of the holder in connection
with the feeding mechanism is concerned, but this holding means is preferred,
independent of its special use, on account of the ease with which the tool may
be attached to, and detached from its holder. In the common form of holder
shewn in Figure 1, in which the drill D is driven into holder C, much force is
necessary to remove the drill, this being done generally by driving a wedge inside
the end, thus forcing the drill or other tool out, an operation that necessitates
the stopping of the machine, and results in injury to the tool and tool holder.
With the improved means of attachment, the tool may readily be withdrawn from
the socket by first raising the spring catch, or, by a stronger pull, without thus
raising it. It will thus be seen that the improved means for holding a tool is of
universal application, and may be used not only in a chuck, but in tool holders of
any other form.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed (as communicated to me
from abroad), I declare that what I claim is :-
1. In a chuck, the combination of a body for attachment to the driver, a socket
piece for receiving the tool or tool holder, an adjustable clamp pressing the parts
together, whereby the friction of the parts may be adjusted in accordance with
the work to be done, and means for holding the clamp in position, when adjusted,
substantially as described.
2. In a chuck, the combination of a body for attachment to the driver, a socket
piece for receiving the tool or tool holder, one of said members being screw
threaded on the outside, a screw clamp surrounding the screw threaded member,
and engaging the other member, whereby the friction may be adjusted in accord-
ance with the work to be done, and a locking nut on said screw-threaded member
for holding the parts in position when adjusted, substantially as described.
3. In a chuck, the combination of a body for attachment to the driver, a socket
piece for receiving the tool or tool holder, one of said members being screw-threaded
on the outside, a friction piece between the body and socket piece, a screw clamp
surrounding the screw-threaded member and engaging the other member, whereby
the friction may be adjusted in accordance with the work to be done, and a locking
mut on said screw-threaded member, for holding the parts in position when adjusted,
substantially as described.
4. A chuck consisting of a recessed screw-threaded body 2, socket piece 3
inserted into said recess, and provided with a reduced neck and shoulders, adjustable
screw-threaded clamping ring 5, surrounding the body and neck, and pressing

page_text: against the shoulders, pressure pieces 4 between the parts, and a locking nut 6 on
the body, for holding the parts in position, substantially as described.
5. A chuck consisting of a plurality of parts having surfaces held in frictional
contact, the pressure being so adjusted that the chuck is rigid under the strain
required for work, but yields under an excess of strain, and having a socket to
receive a tool or tool holder, and a yielding catch adapted to enter a recess in the
side of the tool or tool holder, the catch being constructed to yield and release the
tool or tool holder under a force tending to pull the same from the socket, substan-
tially as described.
6. In a chuck, the combination of a body for attachment to the driver, a socket
piece for receiving the tool or tool holder, an adjustable clamp for pressing the
parts together, whereby the friction of the parts may be adjusted in accordance
with the work to be done, and a yielding catch adapted to enter a recess in the
side of the tool or tool holder, the catch and tool or tool holder engaging_by
rounded or beveled surfaces, whereby the catch will yield and release the tool or
tool holder under a force tending to pull the same from the socket piece, substan-
tially as described.
7. In a chuck the combination of the recessed body 2, socket piece 3, inserted
into sail recess, and provided with a reduced neck and shoulders, adjustable
clamping ring 5, surrounding the body and neck, and pressing against the shoulders,
and pressure pieces 4 between the parts, substantially as described.
8.. A chuck having a socket to receive a tool or tool holder, and provided with a
yielding catch adapted to enter a recess in the side of the tool or tool holder, the
catch being constructed to yield and release the tool or tool holder under a force
tending to pall the same from the socket, substantially as described.
9. A chuck having a socket to receive a tool or tool holder, and provided with a
yielding catch adapted to enter a recess in the side of the tool or tool holder, the
catch and tool or tool holder engaging by rounded or beveled surfaces, whereby
the catch will yield and release the tool or tool holder under a force tending to
pull the same from the socket, substantially as described.
10. The combination of a tool holder provided with a spring catch, and a tool
adapted to slide into said holder, and provided with a recess in its side to receive
the spring catch, the catch and holder engaging by surfaces, one or more of which
is beveled or rounded, substantially as described.
11. As a means for retaining a tool in its holder, the spring-pressed pin 10,
carried by the holder, and having a rounded or beveled end 'adapted to enter a
recess in the side of the tool, substantially as described.
Dated this 25th day of August 1891
NEWTON & SON,
Agents for the Applicant.