Improvements in Chucks for use with Capstan and other Lathes.
Year: 1898

page_text: Date of Application, 25th May, 1898
Complete Specification Left, 27th Feb., 1899-Accepted, 15th Apr., 1899
PROVISIONAL SPECIFICATION.
Improvements in Chucks for use with Capstan and other Lathes.
We, WOLSELEY SHEEP SHEARING MACHINE COMPANY, LIMITED, of Sydney
Works, Alma Street, in the City of Birmingham, Manufacturers, and HERBERT
AUSTIN, of the same address, Works Manager to the said company, do hereby
declare the nature of this invention to be as follows:-
This invention has for its object, more particularly, to improve the construction
of chucks for lathes in which a bar of metal to be operated upon is fed forward
intermittently through a hollow lathe spindle, as in the type of lathes known as
capstan lathes; but the invention is applicable, also, to chucks for other
lathes.
I will describe the invention in relation to a lathe in which it is desired to
feed a bar intermittently through a hollow spindle.
According to a form of chuck which has been used for the purpose, a conical
recess is formed in one end of the hollow lathe spindle, and wedges are arranged
in circular form around the bar to be operated upon, and when moved inwards
these wedges are caused, by bearing against the conical surface of the recess
in the end of the spindle, to press against and tightly grip the bar and thus
prevent it moving endways and at the same time insure that it will revolve with
the hollow spindle. A sleeve which surrounds the end of the spindle is formed
with an inward flange at its outer end which passes behind shoulders of the wedges.
The inner end of the sleeve is provided with an abutment against which pressure
is exerted by suitable appliances to move inwards the sleeve and thus tighten
up the wedges, and the pressure against the abutment is released, to release the
grip of the wedges around the bar, when it is desired that the bar shall be fed
forwards.
The means heretofore employed for moving back the sleeve and tightening up
the wedges involve considerable friction in working, and the special feature of
this invention consists in improved means for use in tightening up the wedges
and releasing them.
These improved means comprise, according to this invention, two or more pairs
of toggle joints, of which each pair consists of a central roller, a spindle passing
loosely through the roller and projecting from each side thereof, and two thrust-
pieces formed at their outer ends to bear, respectively, against a shoulder near
the end of the hollow spindle and against the abutment of the sleeve, and formed
at their inner ends each with a portion which fits against, and extends partially
around, the cylindrical surface of the spindle. Each thrust-piece is formed of a
jawed shape at its inner end, so as to pass along each side of the roller; and it
is preferred to widen out the inner.end of each thrust-piece to increase its bearing
surface along the spindle, and to link together the thrust-pieces by means of a
pair of hoops or rings which, respectively, surround the projecting portions of
the thrust-pieces at the opposite sides of the joint. Openings are formed through
the sleeve to receive the toggle joints, and the toggle joints are conveniently placed
within pockets of the spindle which are formed with sideway recesses to receive

page_text: .
the sideway projecting portions of the joints. A sliding gripping-piece, corre-
sponding to that employed with a chuck above referred to as previously employed,
surrounds the sleeve. When the portion of the interior face of this gripping-
piece which is of the diameter of the sleeve comes across the rollers, the rollers
are held inwards to an extent which brings the thrust-pieces of each pair nearly in
line with one another, and the sleeve is thus moved back as far as possible and
the wedges tightly grip the bar. The gripping-piece is formed with a recess in
its inner face the contour of which, as seen in a longitudinal section of
the gripping-piece, curves gradually from the part of greatest diameter into the
portion of smallest diameter, which is of the diameter of the outside of the
sleeve. When the gripping-piece is moved to bring the recess opposite to the
rollers, the strain upon the toggle joints, and consequently upon the wedges, is
released, owing to the rollers moving into the recess; and when the gripping-
piece is moved back again the rollers are gradually forced inwards, owing to the
curved shape above described of the recess, and the wedges are thus again tightened
between the conical surface of the lathe spindle and the bar.
The abutment of the sleeve which receives the thrust of the toggle joints is
formed with a portion which is screwed inside the sleeve so that it may be
adjusted as to its position endways of the sleeve to adjust the grip of the wedges,
in a manner corresponding to that in which the grip of the wedges is adjusted in
the case of the chuck above referred to as being previously used.
The gripping-piece, by means of which the rollers of the toggle joints are
pressed inwards to cause the wedges to grip the bar, may be moved endways in
any usual or convenient manner. According to one method, which I find con-
venient, a claw which engages with a groove formed around the gripping-piece is
carried by a sliding-piece which is capable of sliding endways within a guide
formed with or carried by the lathe head-stock; and this sliding piece is formed
with a toothed rack, and is moved endways by means of a toothed segment
carried upon a spindle which is mounted in the head-stock and is provided with
an operating handle.
The chuck of the improved character above described may be used also with
an ordinary lathe, for the purpose simply of tightly gripping and holding the
metal or article which is to be operated upon.
Data thin 24th day at Wr... 1000
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Chucks for use with Capstan and other Lathes.
We, WOLSELEY SHEEP SHEARING MACHINE COMPANY, LIMITED, of Sydney
Works, Alma Street, in the City of Birmingham, Manufacturers, and HERBERT
AUSTIN, of the same address, Works Manager to the said Company, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement: -
The invention has for its object, more particularly, to improve the construction
of chucks for lathes in which a bar of metal to be operated upon is fed forward
intermittently. through a hollow lathe spindle, as in the type of lathes known as
capstan lathes; but the invention is applicable, also, to chucks for other
lathes.
We will describe the invention in relation to a lathe in which it is desired to

page_text: feed a bar intermittently through a hollow spindle, after which its application to
other lathes will be perfectly clear with very slight further description.
According to a form of chuck which has been used with a lathe in which it is
desired to feed a bar intermittently through a hollow spindle, a portion of the
interior of the hollow lathe spindle is formed conical and wedges are arranged
in circular form around the bar to be operated upon, and when moved inwards
these wedges are caused, by bearing against the conical surface of the interior
of the spindle, to press against and tightly grip the bar and thus prevent it moving
endways and at the same time insure that it will revolve with the hollow spindle.
A sleeve, which surrounds the end of the spindle, is formed with an inward
flange at its outer end which passes in front of shoulders of the wedges. The
inner end of the sleeve is provided with an abutment against which pressure
is exerted by suitable appliances to move inwards the sleeve and thus tighten
up the wedges, and the pressure against the abutment is released, to release the
grip of the wedges around the bar, when it is desired that the bar shall be fed
forwards. The taper of the conical portion of the opening through the spindle is
such that the wedges become loose therein when released from the pressure by
which they are tightened up therein.
Means, however, which have been employed for moving back the sleeve and
thereby tightening up the wedges involve considerable friction in working, and
very considerable force has to be exerted to tighten up the wedges. The special
feature of this invention consists in improved means for use in tightening up
the wedges and releasing them.
In the drawings which serve to illustrate our invention, Figure 1 is a longi-
tudinal section through the centre of the chuck. Figure 2 is a transverse section
taken on line of Figure 1, looking in the direction of the arrow a. Figure 3
is a front end view of the chuck. Figure 4 is a view of the back or outer side of
one of the toggles hereinafter described, shewing also a portion of the sleeve
hereinafter described; and Figure 5 is a side elevation of the forward portion of
the lathe spindle shewing a back or outer face view of one of the toggles.
A is the hollow spindle through which the bar of metal B, to be operated upon
by the tools, has to be fed forwards intermittently. C is the forward portion of
the bearing within which the spindle runs, and D) a portion of the head-stock of
the machine. E is a collar which is fixed tightly around the spindle and transmits
the endway thrust of the spindle to the forward face of the bearing C. The
wedges F are formed, as usual in this type of chuck, as segments of a ring which
has a conical exterior, and are placed, as is usual, within the conical forward
end G of the interior of the spindle and are tightened up therein to wedge them-
selves between the conical surface G and the surface of the bar B when it is
intended that the bar shall revolve with the chuck; but are released, so as to allow
them to become loose between such conical surface and the bar, when it is desired
to feed the bar forward through the chuck. The forward end of the spindle pro-
jects beyond the bearing C, as shewn, and as is usual with this type of chuck.
The wedges are tightened un, as is usual, by means of a sleeve H which surrounds
the forward end of the spindle and is formed with an inward flange h which
passes in front of shoulders f of the wedges F. The inner end of the sleeve is
provided with an abutment which forms the forward face of a ring J which is
a sliding fit upon the spindle, and is screwed into the hinder end of the sleeve
so that it may be capable of adjustment endways in relation thereto. The sleeve
is moved back, to tighten up the wedges, by means of two or more toggles K
which press at one end against the abutment 6 of the sleeve and at the other
end against abutments c of the spindle. Each toggle consists of a central roller d,
a spindle e passing loosely through the roller and projecting from each side
thereof, and two thrust-pieces g, formed conveniently of curved shape, as shewn,
at their outer ends, which bear against the abutment 6 and one of the abutments c,
respectively, and are formed at their inner ends each with a portion which fits
against and extends partially around the cylindrical surface of the spindle e

page_text: Each thrust-piece is formed of a jawed shape at its inner end, as shewn most
clearly by Figures 4 and 5, so as to pass along each side of the roller; and it
is preferred to widen out the inner end of each thrust piece, as shewn, to increase
its bearing surface along the corresponding spindle, and to link together the
thrust-pieces by means of a pair of hoops or rings i which, respectively, surround
for such purpose the projecting portions of the thrust pieces at the opposite
sides of the joint. The curves at the outer ends of the thrust-pieces g are struck,
preferably, from the axis of the spindle e, and the faces of the abutments b c are
made flat, whereby a rolling action of the ends of the thrust pieces against the
abutments is ensured, and slipping avoided. The portion A¹ of the spindle A
which extends for some distance backwards from the front end of the spindle,
and in which the abutments c are formed, is larger in diameter than the portion
of the spindle which is surrounded by the ring J, and the sleeve H is a sliding
fit endways upon such portion A'. Pockets q are formed in the portion A¹ of
the spindle to receive the toggles, except for the hinder portions thereof which
project beyond the end of such portion A¹, and the forward ends of these pockets
form the abutments c. These pockets are formed with sideway portions q¹ to
receive the sideway projecting portions of the joints. Openings are formed
through the sleeve H to enable the toggles to be put into position, and these
openings have sideway recesses for the sideway projecting portions of the
joints.
A part L, which we terin for convenience the "gripping-piece," and which
corresponds to a part employed for the same or similar purpose in the chuck
referred to as previously employed, surrounds the sleeve H. This gripping-
piece is formed" with a certain length of its interior portion of a diameter to be
an easy sliding fit along the sleeve, and with a recess m around its inner face
the contour of which, as seen in the longitudinal section Figure 1, curves gradu-
ally from the part of greatest diameter into the part which is just a sliding fit
along the sleeve. When this gripping-piece is moved to bring the recess m
opposite to the rollers d, the strain upon the toggles K, and consequently upon
the wedges F, is released owing to the rollers being free to move somewhat into
the recess, and the wedges then release themselves within the conical part G
of the interior of the spindle, the taper of such conical part being, as is usual,
such as to ensure that such will be the case; and when the gripping-piece is
moved back again the rollers & are gradually forced inwards, owing to the curved
shape in section above described of the recess, and the wedges are thus again
tightened between the interior conical surface G of the spindle A and the bar B.
The grip of the wedges may be readily adjusted by screwing the abutment J
along within the hinder end of the sleeve H, that is to say, in a manner corre
sponding to that in which such grip has been adjusted in the case of the chuck
above referred to as having been previously used.
An important feature of the invention consists in the fact that the abutment b
is opposite to the abutments c, so that the points of the abutments against which
the two ends of a toggle, respectively, bear are in a line which is parallel, or
substantially so, with the longitudinal axis of the spindle A, whereby the pressure
exerted in a direction to straighten out the toggles produces a maximum force in
a direction tending to tighten up the wedges, and thus less force is required in a
direction tending to straighten out the toggles than would otherwise be the case.
The gripping-piece L may be moved endways in any usual or convenient manner.
According to a method which we find convenient, a claw M which engages with
a groove N formed around the gripping-piece is carried by a slide P which is
capable of sliding within a guide opening R formed through a portion of the
head-stock D; and this slide P is formed with a toothed rack p and is moved
endways by means of a toothed wheel or segment s carried upon a spindle T
which is mounted in the head-stock and is provided with an operating handle U.
The position of this handle is indicated by broken lines only Figure 1, as it does
not properly appear in such view.

page_text: A chuck of the improved character above described may be used, also, with
an ordinary lathe, for the purpose simply of tightly gripping and holding the
metal or article which is to be operated upon, in which case, of course, it is not
necessary that the spindle shall be hollow throughout its length. The chuck
(apart, of course, from the means by which the gripping-piece is moved endways)
may, in such case, be formed to be screwed at its hinder end upon or within the
spindle or driving plate of the lathe; and may be formed to be screwed to the
spindle in the case, also, in which a bar is fed intermittently therethrough.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what we
claim is
1. In a chuck for use with a capstan or other lathe, a rotative part having a
tapered opening, wedges arranged around the axis of such part and their outer
surfaces shaped to fit against the interior tapered surface thereof, abutments
rigid with said rotative part, a portion mounted to be capable of moving endways
in relation to such rotative part and engaging at its outer end with the outer ends
of the wedges and provided at its inner end with an abutment which is opposite
to the abutments which are rigid with the said rotative part, toggles which bear
at their respective ends against the abutments of the said rotative part and the
abutment of the said portion which is capable of moving endways, the points of
the abutments against which the opposite ends of each toggle press being in a
line which is parallel or substantially so with the longitudinal axis of the lathe
spindle, owing to the relative positions of the abutment of the said portion
which is capable of moving endways and the abutments of the rotative part, and
means for operating said toggles, whereby the wedges may be tightened up or
loosened, substantially as described.
2. In a chuck for use with a capstan or other lathe, a rotative part having a
tapered opening, wedges arranged around the axis of such part and their outer
surfaces shaped to fit against the interior tapered surface thereof, abutments
rigid with said rotative part, a sleeve surrounding such rotative part and capable of
moving endways in relation thereto and engaging at its outer end with the outer
ends of the wedges, and provided at its inner end with an internal ring or collar,
toggles which bear at their respective ends against the abutments of the said
rotative part and against the forward face of the said internal ring or collar, and
means for operating said toggles whereby the wedges may be tightened up or
loosened, substantially as described.
3. In a chuck for use with a capstan or other lathe, a rotative part having a
tapered opening, wedges arranged around the axis of such part and their outer
surfaces shaped to fit against the interior tapered surface thereof, a portion
mounted to be capable of moving endways in relation to such part and engaging
at its outer end with the outer ends of the wedges and provided at its inner end
with an abutment, abutments rigid with said rotative part, toggles each having
two thrust pieces which radiate from a common centre or knuckle, and bear at
their respective outer ends against the abutment of the said portion which is
capable of moving endways and the abutments of the said rotative part, and means
by which the toggles may be pressed in a direction tending to straighten them
out, and the wedges thereby tightened up, substantially as described.
4. In a lathe chuck which comprises a rotative part having a tapered opening
and wedges arranged around the axis of such part and having their outer surfaces
shaped to fit the interior tapered surface thereof, toggles for use in tightening
such wedges within the rotative part, each having two thrust pieces which extend
from a common centre or knuckle, spindles against which the inner ends of the
thrust pieces bear, rollers carried by such spindles, and means for pressing against
said rollers to expand the toggles, substantially as described.
5. In a lathe chuck which comprises a rotative part having a tapered opening
and wedges arranged around the axis of such part and having their outer surfaces

page_text: shared to fit the interior tapered surface thereof and toggles by means of which
such wedges are tightened up within the rotative part, a sliding piece which
surrounds the said rotative part and by the movement of which in one direction
the toggles are pressed inwards to expand them endways, a slide mounted within
a suitable fixed guide and engaged with such sliding piece and itself provided with
teeth, a toothed segment or wheel gearing with such teeth, and a handle by which
such segment or wheel may be turned and the sliding piece thereby operated
through the medium of the slide, substantially as described.
Dated this 24th day of February 1899.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.