Improvements in Machinery for Turning or Facing Small Articles in Metal.
Year: 1893

page_text: Date of Application, 2nd Jan., 1893
Complete Specification Left, 2nd Oct., 1893-Accepted, 2nd Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Machinery for Turning or Facing Small Articles
in Metal.
I, CHARLES JAMES HEWITT of 5 High Street, Prescot in the County of
Lancaster, Master Mechanic, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object a lathe or mechanism that will turn out small
turned objects in metal exact duplicates of each other to the thousandth part of
an inch, and that will do this to a great extent automatically and with greater
accuracy.
The invention may be divided into two parts (1) the spindle and driving
mechanism, (2) the tool carrying and adjustment.
I use, in combination with the ordinary spindle, an internal push spindle. In
connection with this, I mount between two annular discs on the main spindle, two
or more spiral springs working in recess in these discs. One of these discs is
fastened to the push spindle by two keys, the other runs loose on the main spindle
but abuts against a loose cone on this main spindle. The aforesaid springs push
forward the push spindle except when forcibly held back, and this pushing forward
of the spindle closes the chuck which is formed in three parts with radial divisions.
The chuck is opened by a lever worked by means of a treadle or lever or cam
when the machine is wholly automatic. This lever pushes back the push spindle
and also takes off the friction clutch herein described thus stopping rotation of the
chuck.
The friction clutch formed of an internal and external cone is placed between the
two bearings of the main spindle. One cone is fixed to the spindle, the other to
the split coned pulleys, which surround and form part of the friction clutch. The
friction clutch when not pressed by the lever is held to its work by an internal
spring or springs.
The automatic adjustment is as follows-
On the slide of the sliding rest is a capstan head carrying a series of tool holders
fitted in a circular T slot in the same.
These tool holders are accurately regulated
for diameters by means of set pins in the capstan rest, the points coming against
the face of a click on the slide.
The capstan head is revolved by means of a worm and wheel. The worm shaft
is driven by a band. Regulating screws coming against the click stop the rotation
and the band slides on the pulley instead of causing it to rotate. These regulating
screws are cut to a certain uniform pitch and the heads graduated to any required
degree of measurement. The tools are regulated as regards thickness by means of
an shaped piece of steel coming against the points of other set screws.
Lpiece slides on the slide rest.
A projecting piece on the slide rest enters a slot in the
permanent stop to the L piece thus giving a coarse regulation.
is effected by screws on the capstan head which give accurate
tool by regulating the travel of the piece.
The
piece and acts as a
The fine regulation
adjustment for each
The mode in which the aforesaid click is brought into action is as follows:-
A crank spindle is controlled by a spring causing it to normally come into action
except when held back. A crank on this spindle is actuated by a stop on the
leading screw. When, therefore, this stop comes in contact with the crank of the

page_text: crank shaft, it momentarily throws the click out of action, the stop is then released
by hand and the click falls back. The revolving capstan in the meantime has been
released and continues revolving until the next screw coming in contact with the
click is stopped at the exact position for the next tool to work.
To prevent any chance of the thickness set screws changing position, they are
locked by side set screws, the head of the thickness set screws being in the capstan
cut at right angles to them and the said set screws being driven in from above.
Dated this 27th day of December 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Machinery for Turning or Facing Small Articles
in Metal.
.1, CHARLES JAMES HEWITT of 5 High Street, Prescot in the County of
Lancaster, Master Mechanic, 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 has for its object a lathe or mechanism that will turn out small
turned objects in metal exact duplicates of each other to the thousandth part of
an inch, and that will do this to a great extent automatically and with great
accuracy.
The invention is best described by aid of the accompanying drawing:
--
Figure 1 being a side elevation, partly in section, of the lathe complete arranged
for gripping internally:
Figure 2, a plan of the same :
Figure 3, end elevation :
Figure 4, part elevation of the other end :
Figure 5, sectional view of a portion of a lathe arranged for gripping
externally:
Figures 6, 7, and 8, detail views as hereinafter described.
Referring first to the arrangement shown in Figure 1-
A, is the internal push spindle, made solid in this case: B, the external or
ordinary spindle. On spindle B, I mount a sleeve C and an annular disc D or
equivalent frame facing device. E E, Figures 5 and 6, are spiral springs, placed
in recesses in these discs and tending to press them apart. F F are keys fastening
disc D to the push spindle A. The sleeve C is loose on the main spindle B but
abuts against a loose cone G. The springs E, in pressing the two discs apart,
press the push spindle A and its continuation screwed to it as shown, forward, the
continuation fitting the hollow of the chuck which is in three pieces with radial
divisions, the rod A. expands the circle of the latter in proportion as it is pushed
forward.
Figure 5 shows the arrangement when the chuck grips externally.
In this, A is the push spindle which is hollow: B, the external or ordinary
spindle. The chuck H is screwed to the hollow rod and held in position by
nut and spring 2. The section shown in this figure is taken through the
springs E, and the section in Figure 1, through the keys F, Figure 6.
.
The chuck is closed or (in the case of an external holding chuck) opened by a
lever I worked by means of a treadle (or lever or cam when the machine is wholly
automatic). J is a friction cone abutting against the disc D. The lever I, pushing
against this, thus pushes back the push spindle and also takes off the friction clutch
hereinafter described, thus stopping the rotation of the main spindle and of the

page_text: chuck H. When the chuck. grasps externally, Figure 5, its cone formed of
three radial pieces rests in another hollow cone on the push spindle, and thus, by
pushing forward the push spindle, the chuck is contracted. J and K are an
internal or male, and external or female, cone forming a friction clutch. These
are placed between the two bearings L L' of the main spindle B. The cone J can
move longitudinally on the spindle B, the other cone K forms part of the split cone
pulley which surrounds and forms part of the friction clutch.
The friction clutch, when not pressed by the lever, is held to its work by an
internal spring or springs j.
On the top side M of the sliding rest is a capstan head N carrying a series of
tool holders O O fitted in a circular tee slot P in the same. The tools O¹ are
accurately regulated for turning diameters by means of set pins Q (see plan) in the
capstan. Holes or recesses Q' are formed on the underside of the capstan, into which
project the set pins Q. R is a pawl or click, pivotted on a spring actuated rod r on
the slide M and adapted to enter the aforesaid holes or recesses as the capstan_is
rotated and to come in contact with the set pins. Now it will be evident that, by
regulating the set pins Q which rotate with the capstan so that they come sooner or
later against the fixed pawi R, the tools can each be brought to a different position
as regards the work.
The capstan head is revolved by means of a worm and wheel S S¹. The worm
shaft is driven by a band or pulley s. The regulating screws Q, coming against
the click R, stop the rotation and the band slips on the pulley instead of causing it
to rotate. These regulating screws Q are cut to a certain uniform pitch and can be
regulated to any required degree of measurement.
The tools are regulated as regards the thickness of the work by means of an
L-shaped piece T of steel travelling with the capstan N and having a slot t
through which projects a fixed pin p. The turned up portion of T enters a
groove T¹ in the capstan, as shown in Figure 8. Now, by regulating the set pin U,
it will be evident that the piece T will be drawn along and stopped by the
projection p sooner or latter according to the adjustment of the screw U, and a fine
regulation is thus effected.
:-
The mode in which the aforesaid click R is brought into action is as follows:-
A spindle V is controlled by a spring causing it to normally come into action
except when held back. A crank X on this spindle V is actuated by a stop on the
leading screw Y. When, therefore, this stop comes in contact with the crank of the
crank shaft, it momentarily throws the click out of action, the stop is then released
by hand and the click falls back. The revolving capstan in the meantime has
been released and continues revolving until the next screw, coming in contact
with the click, is stopped at the exact position for the next tool to work.
To prevent any chance of the regulating set screws Q or thickness set screws U
changing position, they are locked by set screws q u.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture and use of lathes for turning or facing small articles,
constructed and arranged substantially as herein described: also the following
points taken separately-
(a) The arrangement of spring disc cone inside the split pulleys and its
actuating parts substantially as described.
(b) The double spindle device with or without automatic feed whereby either
interal or external gripping chucks can be used, and fitted on the spindle
with but slight alteration of parts.
(c) The capstan rest substantially as described.
(d) The method of adjusting the tools, whereby they can be automatically
brought into play and act with precision to the thousandth of an inch.

page_text: (e) The method of and device for working the capstan rest in which, a worm
and wheel revolve it and a click device immediately under the operating
tool stops it at the required point.
Dated this 30th day of December 1893.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.