Improvements in Automatic Lathes.
Year: 1898

page_text: Improvements in Automatic Lathes.
I, JAMES BROCKIE, of No. 12, Tyson Road, Forest Hill, in the County of Kent,
Engineer, 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 :—
My invention relates to automatic lathes of the kind in which several tools are
fixed in a turret or its equivalent which moves to and fro longitudinally and also turns
step by step round so that the tools carried by it are made to act successively on
work held in the revolving mandrel, while laterally moving tools serve to shape and
cut off the work. The chief object of my invention is to determine the movements
of the tools in such a manner that their speed can be varied, that a certain cycle of
these movements can be repeated as many times as desired and that the cycle of
movements can itself be varied as desired within wide limits, the mechanism
being so arranged as to form a compact lathe occupying little space beyond that of
the headstock.
I will first describe the general character of the mechanism which may be thus
stated. The movements of the tool holders are effected by cams or their equivalents
which are loose on a continuously revolving shaft, but are engaged with it and
disengaged from it by clutch mechanism as determined by what may be termed a
mechanical commutator having operating studs which can be fixed in it in various
positions, each position determining a certain cycle of movements. The speed of
these inovements can also be varied by the engagement of gearing
of various proportions as determined also by the commutator. Tbus
the commutator has its studs set in certain positions the lathe
goes on automatically repeating the cycle of action determined by the com-
mutator, producing any number of the articles turned all to the same pattern; and
by changing the position of the commutator studs and tools, the movements are so
varied as to produce articles of a different pattern. I shall describe the mechanism
for this purpose referring to the accompanying drawings.
when
Figures 1 and 2 are respectively a side and an end elevation of the headstock of
the lathe and tool holders.
Figure 3 is an elevation partly in section of the rear of the headstock, and
Figure 4 is a part vertical section of the tubular mandrel on the line Q Q of
Figure 3, and part side elevation of the headstock with its rear bracket shewn in
section.
Figure 5 is a sectional plan on the line Y Y of Figure 6 which is a vertical section
on the line X X of Figure 5.
Figure 7 is a front view and Figure 8 a side view of the forming and cut off tools
and their working connections.
Figure 9 is a longitudinal section and Figure 10 is a part transverse section 'and
part front elevation of the clutch mechanism for the crank which works the forming
and cut off tools.
Figure 11 is a part transverse section and part front view, and Figure 12 is a part

page_text: longitudinal section, and part side view of the clutch and cam for working the tool
holder or turret.
Figure 13 is a section on the line Z Z of Figure 14 which is a side view of the
gear shewn in Figure 13 for moving the commutator and varying speed. Both these
figures are turned on their side.
Figures 15, 16 and 17 are enlarged views of the parts of Figures 13 and 14 marked
by corresponding letters, Figures 16 and 17 being respectively sections on the
lines A A and B B of Figure 15.
'
Figure 18 is a front and side view and plan of the coupling disc on the
shaft Jo.
Figure 19 is a section shewing the gear for turning the tool holder or
turret.
Figures 20 and 21 are part longitudinal sections of the mandrel shewing the
clamping levers in their two positions.
Figures 22 and 23 are respectively front and side elevations of the commutator
discs.
Figures 24 and 25 are respectively end and side views of the pawl F⭑.
In the headstock A besides the usual bearings for the mandrel B, bearings are
provided for other shafts hereinafter referred to. The mandrel B has fixed on it
a toothed wheel B³ gearing with a wheel B2 fixed on a countershaft B4 on which
is fixed a pulley B₁ driven by a belt from any suitable motor. On the counter-
shaft B is also fixed a pulley J connected by a belt to a pulley J2 fixed on
another countershaft J which is thus caused to revolve when the mandrel
revolves.
A cam shaft A', which can be driven at various speeds, as will hereafter be described
has on it free to revolve a crank disc G7 and has two barrel cams E10, and C13; it has
fixed upon it a clutch disc and worm wheel G° a clutch disc E¹¹ and a clutch disc D'
for the barrel cam C¹³.
Another shaft E¹ is fitted to revolve and slide longitudinally in bearings A2 formed
in the headstock A. It has fixed on its front end the tool holder E corresponding to
a turret provided with a number of equidistant holes E2 in each of which a tool can
be fixed by screw wedges E³ or otherwise; it has also an equal member of equidistant
bushed conical recesses F to receive the spring bolt F¹. On the shaft E' is also fixed
a boss E having grooves Es corresponding in number and position with the tool holes
of the turret, and between the boss E and a screw collar and lock nut, is fitted, but
not fixed on E¹, a boss E7 carrying a conical roller E8 which is engaged in the grooved
path of the cam E10, so that when this cam revolves the shaft E with the turret E
makes a forward and backward reciprocation for each revolution of the cam E¹º.
the front end of the cam E10 is a single tooth E which once in every revolution of the
cam engages in one of the grooves E5 (see Figure 19) and turns the shaft E¹ and
turret E partly round so as as to bring a fresh tool into operating position. As the
tooth E is situated at the front end of the cam, the turning of the turret only takes
place when the tool is away from the work held in the mandrel.
On
In order to prevent the boss E7 from turning on or with the shaft E¹ it is made
with a fork partly embracing the cam E10. Before the boss E is turned by the
tooth E it encounters in its forward stroke a spring pawl F4 (Figures 24 and 25)
on the end of one arm of a lever F5, the other arm of which is jointed to a rod F
having a hook head F. In the turret E is a groove F" occupied by a ring F2 the
lower part of which has a boss fitted to slide on a fixed sleeve F, and in the upper
part of this boss is a recess containing the spring locking bolt F1 its spring F3
and its disengaging lever F7. As the turret moves to the right the lever F approaches
the head F which at the same time is being moved to the left by the action of E* on the
pawl F and lever F, and thus F7 rapidly meeting F8 is moved so as to withdraw
the bolt F and keep it withdrawn until the turret is turned one step round. The
pawl F then enters the next slot of E4, and the rod F moves rapidly to the right
withdrawing the head F8 from the lever F7 so that the spring F3 causes the bolt F¹

page_text: to enter rapidly the next recess of the turret and so lock it in its new
position.
The mandrel B is, as usual, tubular so that a wire or rod which is to be operated on
can pass through it and be clamped at its right hand or front end. The mechanism
for feeding forward and clamping the wire or rod is arranged as follows. C is the
chuck at the end of the mandrel and C² is the sleeve carrying the clamping jaws at
its front end. In slots of the sleeve C¹ engage shoulders on levers C² which are
pivotted at Cs in a stationary boss in front of which is a sliding piece C moved to
and fro by its groove C³ being connected by a rod C9 to a boss Cio carrying a roller C¹¹
engaged in the cam groove (12. An inner sleeve D¹ is attached to a block 12 having
a groove engaging a stud on a sliding piece D³ which is guided on a rod D* and is
caused to reciprocate by a roller mounted on it and engaged in the cam groove D³.
When the sleeve C¹ is drawn back its front end being split is caused to clamp the
wire or rod inside it owing to its coned end being drawn into a conical seating.
While the wire or rod is so clamped the sleeve D1 retreats and when it has com-
pleted its back stroke the sliding piece C retreats allowing the ends C of the levers C²
to slide along the inclines C5 opening the levers C2 apart so as to allow the sleeve C¹
to advance a little so that its front end no longer holds the wire or rod. The front
end D of the sleeve D¹ is split and its segments clamp the wire or rod with certain
force so that when D₁ advances it carries forward with it a length of the wire or rod
which is again clamped by C while D¹ retreats for a fresh feed. The cam grooves C¹²
and D' are formed in a sleeve which is free to revolve on the shaft A¹ but is clutched
to it as determined by the commutator as will presently be described with reference
to the cam E10.
The forming and cutting off tools are arranged and worked as follows:-
In bearings A³ at the top of the head-stock is mounted a rocking shaft G which
has an arm G2 connected by a link G5 to a crank pin Ge on the disc G7 so that at
every revolution of this disc the shaft G is made to rock to and fro. On a disc G¹
on the front of the shaft G are mounted two toolholders G³ holding suitable forming
and cutting off tools G4 each of which can be set nearer to or farther from the work
by moving the holders G3 on the face of the shaft and clamping them in position
by bolts passing through circularly slotted holes.
It has been said above that the cam shaft A' has on it free to revolve the barrel
cam E10 and the crank disc G' which therefore revolve only when they are clutched
to the shaft. The cam E10 is clutched to the shaft as shewn in Figures 11 and 12.
In the face of the clutch disc E" which is fixed on the shaft A¹ is a recess in which
is fitted a slide E12, urged to the right so that its curved end projects beyond the
periphery of the disc, by two springs lying in a recess behind the slide, one end of
each spring being attached to a pin on the slide and its other end to a pin on the disc
itself. On the inner side of the slide E12 is an inclined notch engaging a pin E"
projecting backwards from a sliding bolt indicated by the dotted lines E13. Upon
the cam E10 is fixed a ring E15 which overhangs the rear of the cam and has in one
part of its circumference a slot to receive the bolt E13. While the bolt E13 is in the
slot of E16 the cam E10 is made to revolve with the disc E" and shaft A. But if as
the disc revolves in the direction of the arrow the sloped projecting end of the
slide E encounters an obstruction fixed close to the periphery of the disc, then
the slide El is pushed in withdrawing the bolt E13 from the slot in the ring E15 so that
the cam E no longer revolves with the shaft A¹. The bolt E13 after being withdrawn
from the slot cannot engage in it again until the shaft A¹ has made a complete revolu-
tion, and then only if the obstruction that caused its withdrawal is removed, in which
case the slide E12 will spring outwards causing the boit E13 to engage in the slot
of E15. The sleeve having the cam grooves (12 and D5 for feeding and clamping the
wire or rod in the mandrel is clutched to the shaft A¹ in the same way as E10. As
shewn in Figures 9 and 10 the crank disc G7 is clutched to the shaft A¹ in a similar
way, but in this case the clutching bolt G" can be withdrawn from the slot in the
ring G8 when the shaft A¹ has made half a revolution. For this purpose besides the
slide G there is another slide G15 which is connected to G13 so that they must move

page_text: together but in opposite directions; both shues having rack teen engaging with a
pinion G free to revolve on the shaft A¹.
The obstructions which serve to unclutch the crank disc G7 and cam E10 from the
shaft A¹ are studs He fixed in the grooved peripheries of discs H¹ (Figures 13 and 14)
fixed on a shaft H, these discs with their studs He constituting the mechanical com-
mutator above referred to. On the shaft H is fixed a ratchet wheel H* engaged by a
spring pawl on a lever H3 which is moved in the one direction by the double cam H²
on the shaft A¹ and is retracted by a spring, so that the shaft H is turned a step
round twice in every revolution of the double cam H2; a spring pawl H6 prevents the
shaft H from turning backwards.
It has been stated above that the speed of the cam shaft A¹ can be varied within
certain limits, to suit the nature of the work on which the tools act. The driving of
A¹ is effected as will be described particularly with reference to Figures 13 to 18 in-
clusive. The shaft J driven by a band on its pulley J2 from the pulley J', as above
described, has on it a pinion J' gearing with a wheel J5 fixed on a shaft J. The
pinion J is connected to the shaft J through a slip clutch which may be like that
shewn in Figure 17 for the wheel J19 allowing the wheel to slip when it is driven faster
than the shaft. The short shaft Jo works in bearings provided on each side of the
wheel J and beyond the right hand bearing it has fixed on it a face disc J7 made
with a groove across it. Into this groove fits the rib of a coupling disc J8 such as is
shewn in Figure 18, which is a disc with a rib projecting at each side, the one rib
being at right angles to the other. The other rib fits a groove in the face'
plate J7 on a short shaft carrying a grooved friction gear wheel J12 which is
thus caused to revolve when the wheel J5 revolves. In a similar manner another
grooved friction gear wheel J12 is coupled, then a worm shaft J and finally the shaft
of another grooved friction gear wheel J16 so that these three grooved wheels and the
worm on Jo all revolve with the wheel J. The bearings for the short shafts that
carry the wheels J12 J12 and J1 are formed in levers J1 J10 and J15 which are pivotted
on a shaft J and have their ends held down by springs to the collar of rods J13.
These rods pass through other levers J on which bear adjustable springs. Each of
these levers J14 extends under one of the commutator discs H¹, so that when a stud H
on one of these discs presses down the end of one of the levers J14 the lever J10
connected to it is raised, bringing one or other of the friction gear wheels J1 J12
or J16 into close contact with a corresponding wheel J3 J3 or J17 which is fixed on
the shaft J, the degree of frictional pressure being determined by the springs bearing
on the lever J14. As the upward movement of J12 J12 or J16 to give driving pressure
is very little, only a small fraction of an inch, the coupling discs J8 allow for this
movement. The worm on Jº gears with a worm wheel J19 free to move in one
direction on a shaft J20 which has a worm J21 gearing with the worm wheel Gº on the
cam shaft A¹. The three wheels J1 J12 and J16 being of different diameters the
speeds imparted by them to the corresponding wheels J3 J3 and J1 to the shaft J and
thence through the shaft J20 to the cain shaft A¹ are different. Also when none of the
three wheels is brought into frictional contact with the corresponding wheel on the
shaft J, the cam shaft is driven at a less speed than any of these wheels can give by a
worm on the boss of J17 driving a worm wheel J18 on the shaft J 20
For producing a number of finished pieces from a wire or rod the first step is to
turn the turret until a stop piece held in one of its tool holes is brought into line
with the mandrel in which position it remains during the movements of the feeding
mechanism.
These movements are effected by a complete revolution of the feeding cams, during
which first the jaws of the chuck are opened, then the wire or rod is fed forward till
it meets the stop held in the turret, (this determining the length projecting from
the chuck,) and then the jaws of the chuck are closed gripping the wire or rod.
The turret stop is then moved back and its register pin is withdrawn, allowing a
partial rotation by which the tool, which is to be first used is brought into line The
turret with this tool is moved at the proper rate determined by the speed gear, and
.

page_text: the motion may be repeated the turret being partly turned at every stroke so that its
six tools may act successively upon the material held in the chuck.
If it is desired to reduce a part of the wire or rod so as to leave a shoulder, a suit-
able tool is fixed in one of the tool-holders on the rocking-shaft and the crank disc is
caused to make half a revolution, bringing this tool to act upon the work, and
returning it, and this may be done either during the operations of the turret or after
they are completed.
A cutting off tool also carried in one of the tool-holders of the rocking shaft is
brought down and returned by the second half revolution of the crank disc, cutting
off the finished work. The stop in the turret may be then again brought into
position, the machine beginning another cycle of operations.
Having now particularly discribed and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. An automatic lathe constructed and operating substantially as described with
reference to the drawings.
2. The combination of the countershafts J and Jo, the coupling discs J8, the friction
gear wheels J12 J12 and J16, shaft J and its worm shaft J20 and the worm gear Ja¹ and
worm wheel G for driving the cam shaft A¹ at various speeds, substantially as
described.
3. The combination of the double cain H2 on the cam shaft A' the pawl lever H³
and its spring pawl the ratchet wheel H* the shaft H and the commutator discs H¹,
substantially as described.
4. In combination with studs on three of the commutator dises the levers J14,
rods J13 and bearing levers J10 for the shafts of the three friction gear wheels J¹² J12
and J16 substantially as described.
5. In combination with studs on one of the commutator discs H₁ the slide E12 in
the disc E, the bolt E¹s and the cam E10 and its ring E16 substantially as described.
6. In combination with studs on another of the commutator discs H the two
slides G13 G1 geared together in the disc G9, the bolt G₁ and the crank disc G7 sub-
stantially as described.
7. In combination with the cam E10 and its tooth E the turret shaft E' and the
turret E with its fittings, substantially as described.
8. In combination with the crank G the rocking shaft G and the forming and
cutting off tools substantially as described.
9. In combination with the cams C12 and D5 the tubular mandrel B with its
feeding and clamping mechanism substantially as described.
10. In an automatic lathe, the combination in one lathe head of a tubular
mandrel, a reciprocating and rotating turret or tool holder, and a rocking shaft
carrying cutting off and forming tools, substantially as described.
Dated this 19th day of December 1898.
ABEL & IMRAY,
Agents for the Applicant.