Improvements in Automatic Lathes or Machines for Making Screws and other Articles.
Year: 1887

page_text: Date of Application, 3rd June, 1887
Complete Left, 5th Mar., 1888
Complete Accepted, 27th Apr., 1888
Improvements in Automatic Lathes or Machines for Making Screws
and other Articles.
I, EMILE DAVIS of 16 Camden Square London N.W. in the County of Middlesex
Engineer, do hereby declare the nature of this invention (a communication to me
from abroad by Georg Heyne and Ernst Heyne trading as Heyne Brothers at
Offenbach on the Main, Germany) to be as follows:-
This Invention relates to improvements in automatic turning, drilling, and screw-
cutting lathes for making small articles, such as screw-bolts, screws for metal work and
the like, nuts, studs, washers, etc., from the stock wire or rod; and for which Letters
Patent were granted to Frank Wirth dated January 27th 1882 No. 431; and it has
for its objects;-
1st. To provide an automatic two-speed driving motion, whereby the speed of the
cam shafts of the machine is increased during the intervals in the working of the
machine when the cutting tools are not actually in operation so that the time consumed
in effecting the changes of position of the parts incidental to the continuous operation
of the machine, is reduced to a minimum, and the output of the machine is thereby
considerably increased.
2ndly. To provide a feed motion whereby the stock length of rod may be more
completely used up than in the previous machine.
3rdly. To provide an automatic stop motion, whereby the lathe will be arrested
when the stock rod has been nearly so far used up that it will no longer be held in
the chuck.
4thly. To provide an improved form of friction clutch for effecting the reversing
motion of the mandrel, when screw-threading.
5thly. To provide a means of holding the tool-carrying slide-rest absolutely
immovable whilst the turning and parting tools carried thereby are in work.

page_text: 6thly. To provide a means of ensuring the return motion of the tool-carrying
slide rest when the tools. carried thereby have performed their work and are to be
brought back to their former position, in readiness for another operation.
The automatic two-speed driving motion constituting the first improvement, is
more particularly designed for machines which make the larger sizes of screws and
which normally run at a comparatively slow speed and it is applied to the transverse
worm shaft by which the pair of longitudinal cam shafts are driven, as described in
the specification of the aforesaid Letters Patent. According to this improvement,
the transverse worm shaft is driven at its normal working speed by a belt on one
pulley, and at certain intervals at a higher rate of speed by another belt which at the
proper times is transferred from a loose to a fast pulley at the same time that the
pulley first mentioned is disengaged and made to run loose. After being driven at
the higher speed for a sufficient length of time to effect the desired changes of position
of the moving parts of the machine the last mentioned belt is transferred again to
its loose pulley and the first or normal-driving pulley is again thrown into gear.
The following is a convenient form of change gear for effecting these variations of
speed. The worm shaft is driven through bevel gear from a short hollow shaft at
right angles thereto upon which is mounted loose, the normal driving pulley which
engages by a clutch with a pulley of smaller diameter which turns with, but is free
to slide along, the shaft and alongside of which is mounted a loose pulley. The fast
and loose pulleys receive a longitudinal motion on the shaft through the agency of a
snail cam upon the worm shaft acting on a sliding rod fitted within the hollow shaft
and connected to the fast and loose pulleys. By the longitudinal motion of these
pulleys, the strap upon them which runs through a stationary belt fork, is transferred
from the one pulley to the other, at the same time that the clutch of the normal
driving pulley is thrown into or out of gear with that of the fast pulley and
consequently with the shaft.
...The improved feed motion constituting the second improvement, consists of a
nipping lever mounted on the end of the tool-carrying slide rest and actuated by a
cam on one of the cam shafts, whereby the stock rod is pressed at proper times,
against the side of the bearing in the end of the slide rest through which its end
projects, in order to be operated on by the turning, cutting, and other tools. The
stock rod is thus gripped and drawn forward through the mandrel and chuck by the
retiring movement of the slide rest after the tools have done their work, so that on
the next advance of the slide rest, a fresh portion of the rod will be presented to the
action of the tools.
The automatic stop motion constituting the third improvement, consists in the
combination with a latch and a spring-actuated belt-shipper of a spring-actuated
hook-shaped dog fitted to slide transversely through the body of the chuck and to
press against the stock rod immediately in rear of the gripping jaws or dogs of the
chuck so that iminediately the end of the stock rod has passed beyond it, the end of
said dog will be caused to project from the circumference of the chuck and act as a
tappet upon the latch above mentioned which retains the belt shipper opposite a fast
pulley, against the tension of a spring. Upon the tappet striking the latch, the
spring is released and the belt thereby thrown on to the loose pulley, and the machine
stopped automatically.
The friction clutch constituting the fourth improvement, is used in lieu of the
sliding collar and pair of dog clutches. described in the specification of the
aforesaid patent; and consists of a pulley having an internally V-grooved
rim, and of a number of correspondingly V-edged segments mounted
slide radially upon a plate within the rim of the pulley and which are thrown
outwards so as to engage with the V-groove therein, by a sliding conical boss
or collar which comes within friction rollers on the inner ends of said segments.
to
The fifth improvement consists of an adjustable or screw stop mounted upon the
bed whereon the tool carrying slide rest moves and against which stop, the slide rest
abuts when it reaches the end of its course-that is to say-so long as the highest
part of the cam which gives its traversing motion, is acting upon it, whereby the

page_text: slide rest is held firmly and without shake between the stop and the cam, so long as
the turning and cutting off tools are in work.
In connection with this stop, the push rod, through which the cam actuates the
slide rest, is provided with a spring which will yield and allow for any defective
adjustment of the stop, and prevent jamming of the machine.
The sixth improvement is particularly adapted for large machines suited for heavy
work; and consists in the cinployment of a cam and lever for ensuring the return
motion of the slide rest after the tools have done their work, the cam and lever being
used in addition to the springs usually employed for the purpose, and being adjustable,
in order that they may be adapted to suit the variable length of traverse of the slide
rest, required for different kinds of work.
E. DAVIS.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Automatic Lathes or Machines for Making Screws
and other Articles.
I, EMILE DAVIS of 16, Camden Square, London N.W. in the County of Middlesex,
Engineer, do hereby declare the nature of this invention (a communication to me
from abroad by Georg Heyne and Ernst Heyne trading as Heyne Brothers, at
Offenbach-on-the-Main, Germany) 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 improvements in automatic turning, drilling, and screw-
cutting lathes for making small articles, such as screw-bolts, screws for metal work
and the like, nuts, studs, washers, etc., from the stock wire or rod; and for which
Letters Patent were granted to Frank Wirth dated January 27th 1882, No. 431;
and it has for its objects ;-
1st. To provide an automatic two-speed driving motion whereby the speed of the
cam shafts
the machine is increased during the intervals in the working of the
machine when the cutting tools are not actually in operation, so that the time con-
sumed in effecting the changes of position of the parts incidental to the continuous
operation of the machine, is reduced to a minimum and the output of the machine is
thereby considerably increased.
2ndly. To provide a feed motion whereby the stock length of rod may be more
completely used up than in the previous machine.
3rdly. To provide an automatic stop motion, whereby the lathe will be arrested
when the stock rod has been nearly so far used up that it will no longer be held in
the chuck.
4thly. To provide an improved form of friction clutch for effecting the reversing
motion of the mandrel when screw-threading.
5thly. To provide a means of holding the tool-carrying slide rest absolutely
immovable whilst the facing and parting tools carried thereby are in work.
6thly. To provide a means of ensuring the return motion of the tool-carrying slide
rest when the tools carried thereby have performed their work and are to be brought
back to their former position in readiness for another operation.
Reference is to be had to the accompanying drawings forming part of this
specification, wherein figure 1 is a plan view of the entire machine provided with the
improvements referred to under the second, third, and fifth heads. Figure 2 is a
plan partly in section, of the rear end of the machine from which the cam shafts are
driven, shewing the improvements referred to under the first head. Figure3 is a cross-
section of the bed of the machine, on line 1-1 figure 1, shewing the improvement
referred to under the second head. Figure 4 is a cross-section on line 2-2 figure 1,
shewing the improvement referred to under the third head. Figuro 5 is a face view
(parts being removed) and figure 6 a section on line 3-3 figuro 5, of the clutch

page_text: referred to under the fourth head. Figure 7 is a plan of the slide rest at the front
end of the machine, shewing the improvements referred to under the 5th and 6th
heads. The same letters of reference indicate the same parts in all the figures.
Referring to figure 2, the automatic two-speed driving motion therein illustrated, is
more particularly designed for machines which make the larger sizes of screws and
which normally run at a comparatively slow speed, and it is applied to the transverse
worm shaft
by which the pair of longitudinal cam shafts B B are driven, as
described in the specification of the aforesaid Letters Patent. According to this
improvement, the transverse worm shaft A is driven at its normal working speed by
a belt on a pulley C and at certain intervals at a higher rate of speed by another belt
which at the proper times is transferred from a loose pulley D to a fast pulley D¹ at
the same time that the pulley C is disengaged and made to run loose. After the
shaft A has been driven at the higher speed for a sufficient length of time to effect
the desired changes of position of the moving parts of the machine, the last mentioned
belt is transferred again from the fast pulley D¹ to the loose pulley D and the first or
normal driving pulley C is again thrown into gear. The following is a convenient
form of change gear for effecting these variations of speed;-The worm shaft A is
driven through bevel gear E from a short hollow shaft F mounted to rotate in the
boss G at the end of a bracket G at right angles to the shaft A. The normal
driving pulley C rotates freely on the quill or tubular extension g of the boss G¹ and
engages by a clutch H' with the pulley D' which is of considerably smaller diameter
than the pulley C and which is caused by a cross-pin d passing through a slot in the
shaft to turn with, whilst free to slide along, the shaft F, the loose pulley D running
on the boss of D' and accompanying it in its to and fro motion. The fast and loose
pulleys DD receive longitudinal motion on the shaft F through the agency of a
snail can I upon the worm shaft A the periphery of which acts on a sliding rod f
fitted within the hollow shaft F and bearing against the key d which makes the
pulley D' fast on the shaft F, a spring d' confined within the outer end of the shaft F
returning them to their normal position when the snail is withdrawn from the rod f.
By the longitudinal motion of these pulleys D D¹ the strap upon them which runs
through a stationary belt fork, is transferred from the one pulley to the other at the
same time that the clutch H connecting C and D¹ is thrown into, or out of, gear
thereby engaging or disengaging pulley C with the shaft F. The snail I is movable
along, but turns with, the shaft A and it is brought at the proper times into or out of
position to act on the rod by a cam J on one of the cam shafts B or B¹ acting
through a bell crank lever held up to the cam by a spring j¹. K is a clutch for
throwing the worm shaft A out of gear when required.
The improved feed motion shewn in figure 3, consists of a nipping lever L mounted
on the end of the tool-carrying slide rest M and actuated by a cam N on one of the
cam shafts B or B¹ whereby the stock rod O is pressed at proper times by a jaw l
against a corresponding jaw m also carried by the end of the slide rest M through
which the end of the stock rod projects, in order to be operated on by the turning,
cutting, and other tools. The stock rod O is thus gripped and drawn forward through
the chuck P, figure 1, by the retiring movement of the slide rest M after the tools
have done their work so that on the next advance of the slide rest a fresh portion
of the rod will be presented to the action of the tools. The jaw is pivoted to
the lever L in order that it may be thrown out of the way when inserting a
fresh length of stock rod. A shoulder bearing on the lover L holds it in position
and takes the thrust. The jaw m is fixed to an adjustable arm m¹ whereby it may
be set to suit stock rods of different diameters. The slide rest M is moved forward
by the cam Y and drawn back by springs M' as in the previous patent aforesaid, the
extent of its backward motion as shewn in dotted lines in figure 7, and conse-
quently the amount of feed, being determined by a screw stop M³. This feed motion
is used in lieu of the gripping jaws on the mandrel and their operating cams and
levers described in the previous patent aforesaid as periodically feeding up the
stock wire when the latter is released by the jaws of the chuck. Being carried
on the slide rest, it enables the stock-wire to be more completely used up than

page_text: when fed by gripping jaws upon the mandrel as in the former case. Moreover, it is
of much more simple construction.
The automatic stop motion shewn in figure 4 consists in the combination with a
catch or trigger and a spring actuated belt shipper (not shewn) of a spring
actuated tappet R fitted to slide transversely through the body of the chuck P
and having a lug or feeler to press against the stock rod immediately in
rear of the gripping jaws or dogs of the chuck so that immediately the stock rod
has been so far used up that its end has passed beyond the feeler, the tappet R
will be caused to project far enough from the circumference of the chuck to act
upon the spring cushioned head 7 of the catch or trigger and disengage it
from the hooked end of the sliding rod S which is connected with the belt shipper.
The rod S is provided with a handle s whereby it is drawn down in its guides and
engaged with the trigger Q, the act of drawing it down moves the belt shipper
opposito the fast pulley on the counter shaft from which the whole machine is
driven, puts in tension a spring connected with the belt shipper and tending to
move the latter opposite the loose pulley. So long as the trigger remains in
engagement with the rod S the belt shipper keeps the belt on the fast pulley, but upon
the tappet striking the trigger the spring is released and the bolt thereby thrown
on to the loose pulley, thus stopping the machine automatically.
The friction clutch shewn in figures 5 and 6 is used in lien of the sliding collar and
pair of dog-clutches described in the specification of the aforesaid patent; and it
consists of a cone pulley T having an internally V-grooved rint and of a number of
correspondingly V-edged segments U mounted to slide radially upon a plate V
within the rim of the pulley, the plate being carried by a boss fast on the hollow
mandrel H. The segments U are forced outwards so as to engage with the V-grooved
rim t by a sliding slightly conical boss or collar W which comes within friction rollers
on the inner ends of the slide blocks of the said segments. The segments U are
screwed to blocks fitted to slide in dovetailed radial grooves in the plate V and
are pressed inwards by springs U¹ contained in cavities formed in the bottom of the
said grooves and in the back of the slide blocks and confined between the end of the
one cavity and the opposite end of the other cavity in such manner as to tend to draw
the segments inwards. To enable the segments Ŭ to be adjusted for wear, the holes
through which the screws pass are oblong and conical headed screws u¹ bear against
the rear ends of the segments and form an adjustable abutment for them. The
collar W is operated through a forked lever from a cam on one of the shafts B or B¹,
and the opposite end of the collar acts on the segments of another similar clutch and
cone pulley (not shewn) the two cone pulleys being of different diameters and
answering the same purpose as the pulleys referred to by the letters P¹ P¹¹ in the
specification of the previous patent aforesaid.
The adjustable or screw stop a shewn in figure 7 is mounted upon the bed whereon
the tool-carrying slide rest M. moves and against which stop the slido rest abuts when
it reaches the forward end of its course (that is to say, so long as the highest part of
the cam which gives it its traversing motion, is acting upon it) whereby the slide
rest is held firmly and without shake, between tlie stop X and the cam Y so long as
the facing and parting tools are in work. In connection with this stop, the push
rod y through which the cam actuates the slide rest is fitted to slide through the slide
rest and is held up towards the cam by a very strong spring y¹ which will only yield
when it is necessary to allow for any omission to adjust the stop X with regard to the
cam Y and so prevent jamming of the machine.
The sixth improvement also shewn in figure 7 is particularly adapted for large
machines suited for heavy work; and it consists in the employment of a cam Z and
lever for ensuring the return inotion of the slide rest M after the tools have done
their work, the cam Z and lover Z being used in addition to the springs M' usually
employed for the purpose. The lever Z is pivoted to the bed of the machine and
connected by a link with a push rod acting against the front of the slide rest M.
The cam Z is adjustablo in order that it may be adapted to suit the variable length of
traverse of the slide rest M required for different kinds of work. This adjustment is
z

page_text: effected by making the cam Z free to slide on its shaft with a groove and feather
connection, and connecting the cam to a block Z2 fast on the shaft by means of an
adjusting screw 2².
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
1st. In an automatic lathe or machine for making screws and other articles, the
automatic two speed driving gear applied and operating substantially as specified.
2nd. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the feed motion consisting of fixed and movable nipping jaws
carried by, and deriving their feeding motion from the tool slide rest and their
nipping motion from a cam, substantially as specified.
3rd. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the automatic stop motion consisting in the combination with a
self acting belt shipper and latch or trigger to retain the same in operative position
of a spring actuated tappet mounted transversely in the chuck and having a fecler
which so long as it bears against the stock wire or rod holds the tappet retracted clear
of the latch, the tappet when no longer so retained being thrown by its spring into
position to act on the latch and release the belt shipper, as specified.
4th. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the combination with the hollow mandrel of a cone pulley,
friction clutch placed at each side of, and operated by, a sliding collar on the mandrel,
each clutch being constructed and operating substantially as specified.
5th. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the combination with the tool carrying slide rest and its
operating cam of the stop applied to hold the slide rest immovable whilst the facing
or parting tools are in operation, as described.
6th. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the combination with the slide rest, its operating cam, and the
stop for holding it immovable, of a spring pressed push rod capable of transmitting
motion to the slide rest under normal conditions and of yielding in case of need, as
described.
7th. In an automatic lathe or machine for making screws and other articles from
the stock wire or rod, the combination with the tool carrying slide rests of a cam
acting on the rest, substantially as and for the purpose described.
Date : KIL
M
1000
E. DAVIS.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.