Improvements in and relating to Tool Chucks or Holders.
Year: 1895

page_text: ate of Application, 24th Sept., 1895-Accepted, 26th Oct., 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Tool Chucks or Holders.
We, JAMES TEXTER FINK, Machinist, and ALBERT STEPHAN, Builder,
both citizens of the United States of America, and residing respectively, at
1412 S Street North West, in the City of Washington and District of Columbia, and
on Grant Street, Mount Pleasant, in said District of Columbia, United States of
America, 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 :-
Our invention has relation to tool chucks, namely, chucks for holding drills, taps,
and other tools, and it has for its object certain improvements whereby the efficiency.
and durability of the chuck are materially enhanced, and the construction thereof
simplified and cheapened; and it has for its further object the combination with
the locking and releasing ring of the chuck, of an attachment adapted to be used
in tapping nuts, whereby when the tap is full the ring is automatically moved to
release the tap.
+
But that our invention may be fully understood, we will describe the same in
detail, reference being had to the accompanying drawings, in which
Figures and 2 are side and end views, respectively, and Figure 3 a longitudinal
central sectional view of a chuck embodying our invention; and Figure 4 is a
perspective view of the attachment.
The chuck comprises as usual, a head A, and a taper shank a flattened at its
outer end. The head A has a cylindrical axial bore for the reception of the
cylindrical shank d of the drill D, said shank having its outer end d¹ flattened to fit
a bearing formed between two cylindrical steel pins pp, driven through the chuck
head A at the inner end of the bore thereof, said pins having their proximate
faces p' within the bore of the chuck head A, flattened to form the bearing above
referred to for the correspondingly flattened end d¹ of the shank of the tool D, the
said pins performing the function of a driver, in that they lock the tool to,
and cause it to revolve with, the chuck, and at the same time take up the whole
of the torsional strain of such tool D, as will be readily understood.
The tool D is locked in its seat in the chuck head A against endwise motion, by
means of a two-armed or centrally pivoted locking dog or lever L. having a nose or
pin adapted to project into a suitable annular groove, notch, or hole in the
shank d of the tool D, said lever L being pivoted in a longitudinal slot a' formed in
the head A of the chuck. The upper face of the lever is concave, or substantially
so, and it is provided at its outer end with an upwardly projecting lip, acting
as a stop for an actuating ring R that slides freely on the head A. The relative
arrangement of the locking lever L is such that its ends will project sufficiently
above the periphery of the head A as to adapt the actuating ring R to tilt the
lever L in one or the other direction, to bring its pin into or out of engagement
with the groove or notch d² in the tool shank, according as said ring is moved
towards the front or rear end of the said lever, as will be readily seen from an
inspection of Figure 3.
&
In practice we preferably provide the lever L with a detachable pin l, having
substantially cylindrical head fitting a corresponding seat in the lever, said pin
being held against lateral movement in its seat by the proximate walls of slot a³ in
head A, as will be readily understood, so that in case the pin should accidentally
become broken, another may be substituted.

page_text: In order to protect the chuck against wear due to thrusts of the tool, we provide
one or more steel wear plates at the inner end of the bore in rear of the driver
pins pp, that may also serve to firmly hold said wear plates in place. In practice
the pins p p are simply driven into suitable holes in the chuck head A, so that
they can readily be removed when this becomes necessary from any cause, as
for example, when it becomes necessary to remove a worn out wear plate, to be
replaced by a new one, or when it becomes necessary to remove one or both
pine, when worn out, for the substitution of others.
We are aware that chucks have, before our invention, been provided either
with pivoted gripping jaws, or with a locking lever adapted to be actuated by
a 'sleeve movable on the head of the chuck, in all such constructions, however,
the tool holding device or devices are also made to perform the function of
drivers, that is to say, they not only prevent the tool from falling out of the chuck,
but also lock it thereto, so as to revolve therewith, the whole of the torsional
strain of the tool being taken up by such devices. When serrated gripping
jaws are employed, they are apt to slip, and they are rapidly cut away under
the thrust of the tool, while if the latter is simply locked to the chuck by a
pin on a locking lever, the torsional strain alone, especially in power drills, or
in tapping nuts, is generally sufficient to wrench the pin from the lever, as it is
not possible to provide room for a sufficiently strong lever, and pin, and the
tool shank with a correspondingly deep seat for the pin, to resist such strain,
without increasing the dimensions of the chuck to such an extent as to render it
practically unavailable for use, and without weakening the tool to such an extent
as to render it liable to break.
There is, however, another factor that contributes to the rapid destruction
of the locking pin, namely the thrust, because a comparatively slight wear of
the inner end wall of the bore in the chuck bead will result in sufficient end wise
play of the tool or drill as to cause the latter to hammer on the pin.
All of the above-recited difficulties are avoided by our invention, which has
the further advantage of admitting of a compact construction, which is at the
same time very simple, and admits of making all the parts that are liable to
wear, of steel, in fact the entire chuck may be made of this metal without
materially increasing the cost of its construction beyond that of the best chucks
now made. On the other hand, should a tool break, it can readily be removed and
another substituted without stopping the machine, which is also a great advantage
in that considerable time is saved.
In machines for tapping nuts provided with tap chucks, as heretofore constructed,
it is necessary to stop the operation of the machine whenever a tap is full, for the
This
removal of the full tap and the substitution of an empty one therefor.
involves considerable loss of time and labor, and this we avoid by means of an
attachment connected with the ring R, that controls the locking lever, said
attachment projecting sufficiently beyond the face of the chuck and adapted to
impinge upon the uppermost nut on a full tap, whereby said ring is automatically
moved upwards along the head of the chuck, thereby releasing the lever L from
the full tap, which is left behind when the chuck again commences to move upward
so that an empty tap can be inserted into the chuck during its upward or receding
motion without stopping the machine.
Any suitably constructed device can be used for the purpose, and as this device
is not subjected to any great strain, in that its function is simply to lift the freely
sliding ring R as the chuck is about to reach the limit of its operative or downward
movement sufficiently to rock the lever L out of engagement with the tap
the said device can be constructed of very light material, as wire, or thin shee
metal.
As an example, we have illustrated the attachment M as consisting of a shee
metal plate m perforated for the free passage of the tool, and provided with arın
perforated near their ends for the passage of set screws m³, screwing into sockets i
the ring R. Instead of perforations, the armis m² of the plate m may be provide

page_text: with longitudinal slots for the passage of the screws m', whereby the plate m is
made adjustable, relatively to the end face of the chuck, so as to be made operative
with a greater or less number of nuts on the tap, and, to limit the upward'
movement of the ring R and prevent the same from sliding over the tail of the
lever L.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. A chuck having a cylindrical bore provided with a bearing at its inner end to
hold a tool against rotation without interfering with its endwise motion, and a ring
sliding freely on the head of the chuck; in combination with a lever of greater
length than the width of the ring pivoted in said head and adapted to lock a
tool against end wise motion, said lever provided with a lip at its outer end adapted
to limit the movement of the ring in one direction, and with a tail adapted to
project into the plane of notion of said ring when the forward end of said lever is
depressed by such ring, for the purpose set forth.
2. A tool chuck provided in its head with a cylindrical bore, and with a bearing
formed by two spaced pins near the inner end of said bore and adapted to receive
between them the flattened end of the shank of a tool and hold the latter against
rotation without interfering with its end wise movement, a thrust or wear plate or
plates at the inner end of the bore held against displacement by the aforesaid pins,
and the lever L pivoted in the head of the chuck and provided with a pin adapted
to engage the shank of the tool and hold the latter against end wise motion, in
combination with the ring R of the same interior diameter as the exterior diameter
of the head of the chuck, said ring adapted to slide on said head and move the
lever into and out of its operative position, substantially as and for the purpose
set forth.
3. A tool chuck provided in its head with a cylindrical bore and with a bearing
formed by two removable pins having proximate flat faces within the bore and
adapted to receive between them the flat end of the shank of a tool and hold the
same against rotation without interfering with its end wise motion, a thrust or wear
plate or plates at the inner end of the bore, held against displacement by the
aforesaid pins, and the lever L pivoted in the head of the chuck and provided with
a removable pin adapted to engage the shank of the tool and hold the same against
end wise motion; in combination with the ring R of the same interior diameter as
the exterior diameter of the head of the chuck, said ring adapted to slide on said
head and move the lever into and out of its operative position, substantially as and
for the purpose set forth.
4. The combination with a tool chuck provided in its head with a seat for the
cylindrical shank of a tool; of a lever pivoted in said head, and a pin detachably
connected with said lever and adapted to engage the tool shank, and means, as the
ring R, adapted to move the lever into and out of its operative position, substantially
as and for the purpose set forth.
5. A chuck adapted to receive and hold a tool against rotary movement, a locking
device to hold said tool against end wise movement, and a sliding element adapted
to control said locking device; in combination with an attachment such as
described connected with the sliding element and adapted to move the same so as
to release the locking device from the tool, substantially as and for the purpose
set forth.
6. The combination with a chuck provided with a cylindrical bore and a bearing
near its inner end, a tap having a cylindrical shank provided with a flattened end,
said shank and flattened end respectively fitting the aforesaid bore and the bearing
therein, and a lever adapted to engage the tap and hold it against end wise
movement in the bore; of a ring sliding freely on the head of the chuck and
adapted to move the lever into and out of engagement with the tap, an actuating

page_text: device connected with the ring and projecting beyond 'the face of the chuck, said
actuating device adapted to come into contact with the uppermost nut on the tap
when said tap is full, for the purpose set forth.
Dated this 24th day of September 1895.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.