Improvements in Turning Lathes.
Year: 1892

page_text: Date of Application, 22nd June, 1892
Complete Specification Left, 21st Mar., 1893-Accepted, 6th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in Turning Lathes.
We, ALEXANDER ROBERTSON of Dawson Terrace, Carron in the County of
Stirling, Engineer GEORGE FINDLAY LOUDON, JAMES TAIT STUART and
HUGH LOUDON HOPKIN all of the firm of Loudon Brothers, Tool Makers, Clyde
Tool Works, Johnstone in the County of Renfrew, and 46 Waterloo Street,
Glasgow, in the County of Lanark, do hereby declare the nature of this invention
to be as follows:-
This invention relates both to screw cutting lathes and also to lathes for ordinary
turning purposes and as regards screw cutting lathes it has for its object to provide
simpler means of adapting lathes to cut screws of different pitches by the change of
one wheel ouly on the end of the leading screw instead of as heretofore changing
wheels intermediate between the speed mechanism and the wheel on the end of the
leading screw.
Under the invention the backward and forward speed mechanism is of ordinary
construction and is driven from the lathe spindle in the usual way. The backward
and forward speed mechanism is by one of its wheels geared with a pinion keyed
upon a sleeve loosely surrounding the shaft or stud upon which the speed mechanism
oscillates in changing from forward to backward speed and vice versa, the pinion
being geared with a wheel of larger diameter on a sleeve carried by a quadrant
which is centred upon the said stud and is capable of swinging through an arc.
(For purposes of illustration the pinion may have twenty teeth and the wheel
eighty teeth.) On the first mentioned sleeve there is also keyed a wheel and on
the second mentioned sleeve a pinion and also for illustration the wheel may be
supposed to have sixty and the pinion forty teeth. The arrangement is such that
when the twenty tooth pinion in gear with the eighty tooth wheel the forty tooth
pinion is out of gear with the sixty tooth wheel and vice versa but in any event the
forty tooth pinion and eighty tooth wheel rotate together with their sleeve which
is carried upon an inner sleeve constituting part of the quadrant. Through this
inner sleeve a stud passes the head of the stud which is enlarged being situated in
a quadrantal slot or groove made in the framing of the lathe whilst its other end is
screwed and has a screw key or nut upon it to bind the parts in their adjusted
position.
The eighty tooth wheel is geared with a pinion or a wheel on the end of the
leading screw and according to the diameter of this pinion or wheel the fineness or
coarseness of the pitch is adjusted the quadrant being swung backwards or forwards
on its centre to gear these wheels properly with each other when the pitch is
changed. To provide for further adjustment of the pitch the sleeve carrying the
wheels supported by the quadrant is capable of horizontal movement on the sleeve
of the quadrant so as to gear the forty tooth pinion with the sixty tooth wheel on
the sleeve above or move it out of gear to the slower motion before referred to.
Under a modification instead of making a quadrantal slot in the frame in which
the pin or stud works the stud may be fixed in the framing of the lathe and a slɔt
made in the quadrant carrying the wheels.
The invention further relates to an improved turret for carrying the tools on the
slide rests of lathes and to improved means for locking the same in position on the
slide. Under the invention the turret is made square so that it may carry two
three or more tools and its base has two semi-circular grooves made in it at right
angles to each other. The turret is fitted upon a circular neck projecting upwards
from the slide and the lock consists of a circular bar or bolt which has a part cut

page_text: out so that when turned in one direction it presents a flat face at the base of the
turret in which position of the bolt the turrent is unlocked and may be turned
round to present another tool. The outer end of the lock bar has a crank handle
applied to it and in the side of the slide a pin is fixed against which in turning the
lock the ends of a semi-circular collar upon it abut so preventing the lock from 5
moving too far in either direction.
Dated this Twenty-first day of June 1892.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Turning Lathes.
We, ALEXANDER ROBERTSON of Dawson Terrace, Carron in the County of
Stirling, Engineer, GEORGE FINDLAY LOUDON, JAMES TAIT STUART and HUGH
LOUDON HOPKIN all of the firm of Loudon Brothers, Tool Makers, Clyde Tool
Works, Johnstone in the County of Renfrew, and 46 Waterloo Street, Glasgow, in
the County of Lanark, 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 relates both to screw cutting lathes and also to lathes for ordinary
turning purposes and as regards screw cutting lathes it has for its object to provide
simpler means of adapting lathes to cut screws of different pitches by the change of
one wheel only on the end of the leading screw instead of as heretofore changing
wheels intermediate between the speed mechanisni and the wheel on the end of the
leading screw.
The invention is illustrated under several modifications on the accompanying
drawings and in one modification shewn by Figures 1, 2 and 3 Sheet 1 which are
respectively a side elevation, an end elevation and a longitudinal section of part of
a lathe, the backward and forward speed mechanism is of ordinary construction and
is driven from the lathe spindle x in the usual way. The backward speed and the
forward speed mechanisms are each by one of their pinions a or b geared with a
pinion c cast or keyed upon a sleeve d loosely surrounding the shaft or stud e upon
which the speed mechanism oscillates in changing from forward to backward speed
and vice versa.
The pinion c is geared with a wheel of larger diameter keyed on a
sleeve g carried by a quadrant which is centred upon the said stude and is capable
of swinging through an arc. (For purposes of illustration the pinion c may have 20
teeth and the wheel f 80 teeth.) On the sleeve d there is also keyed a wheel i and
in the sleeve g there is keyed a pinion j and also for illustration the wheel i may be
supposed to have 60 and the pinion j 40 teeth. The arrangement is such that when
the 20 toothed pinion c is in gear with the 80 toothed wheel the 40 toothed pinion j
is out of gear with the 60 toothed wheel i and vice versa but in any event the
40 toothed pinion; and 80 toothed wheel fare by the same or separate keys secured
to and rotate together with their sleeve g which is carried upon an inner sleeve k
constituting part of the quadrant. Through this inner sleeve ka stud / passes the
head of the stud which is enlarged being situated in a quadrantal slot or groove m
made in the framing of the lathe whilst the other end of the stud is screwed and has
a screw key or nut n upon it to bind the parts in their adjusted position. The
80 toothed wheel is geared with a pinion o on the end of the leading screw p and
according to the ratio of the diameters of the wheel o on the leading screw and the
pinion c on the sleeved the fineness or coarseness of the pitch of the screw to be cut
is adjusted the quadrant being swung backwards or forwards on its centre to gear
these wheels properly with each other when the pitch is to be changed. To provide
for further adjustment of the pitch of the screw to be cut a distance piece q
inserted between the inner end of the sleeve g and the quadrant / and by removing
is

page_text: the said piece the sleeve 9 carrying the wheels j, f can be slid inwards on the
sleeve so as to gear the 40 toothed pinion j with the 60 toothed wheel i on the
sleeve d.
Under a modification illustrated in end elevation by Figure 4 and in vertical
section by Figure 5 instead of making a quadrantal slot m in the frame in which the
pin or stud works a stud r may be fixed in the framing of the lathe and a slot m'
made in the quadrant / carrying the wheels f, j. With this arrangement a pinion c'
of say 20 teeth runs loose on a stud c² attached to the quadrant in a position to
take the wheel on the same pitch circle as the said wheel is shown in gear with
the pinion and by unshipping the wheels f and j and placing the wheelf in the
position of the wheel j, it will gear with the wheel c¹ and enable the workman to
gear up for fine pitches, further by unshipping f and c and placing f in the position
of c it will enable him to gear for coarse pitches. The chief points in this arrange-
ment are, the constant position of the centre stud on the quadrant carrying
the intermediate gear and the pivoting of the quadrant on the stud carrying the
pinion instead of on the leading screw. The quadrant is provided with a radial slot
of a length sufficient to allow of the gear wheel on the intermediate stud to pitch
with wheels on the leading screw of from 20 to 120 teeth thus enabling all pitches
of screws to be cut without altering the centre position of the intermediate gear and
by changing one wheel only in the train. Thus in a lathe having a leading screw
of two threads per inch by placing a wheel of 20 teeth on the leading screw and
connecting the said wheel and the wheel f, a screw having one thread per inch is
obtained and by substituting other wheels up to 120 teeth and gearing them with
the wheelf to intermediate pitches up to six threads per inch are obtained. Again
by placing a wheel of 70 teeth on the leading screw and gearing it with the
wheel seven threads per inch are got and by substituting intermediate wheels up
to 120 teeth pitches up to and including twelve threads per inch are obtained and
so on.
Under a further modification shewn in end elevation by Figure 1 and in vertical
section by Figure 2 and in sectional plan at Figure 3 Sheet 2, which is especially
applicable for boring holes in solid metal by means of a self-acting feed a swing
brackets is provided to carry the pinions for the right and left hand feed gear, the
said bracket being pivoted on a boss cast on the back stay plate t. This stay plate
is formed with two slot holes u and through one of which a set or pinching
screw w is passed to bind the swing bracket s in position and when changing the
direction of the feed this set screw is removed from one slot to the other the
bracket being swung over accordingly. The pinions i and care arranged to slide
on the sleeved so that either pinion can be geared with the pinion on the lathe
spindle through the pinions a, b, fitted to the swing bracket s. A sleeve attach-
ment w¹ slides on the stay rod which has a groove made to receive a key to keep
the sleeve in the desired position, which key is fixed by a set screw.
The quadrant is pivoted on a boss cast on the lower part of the back stay plate
and is provided with a stud and sleeve to carry the intermediate wheels. One end
of a stud r is fitted to the lathe bed the other end passing through the radial
slot m' in the quadrant a nut being provided for fixing it in the desired position.
With this arrangement various pitches are obtained without moving any wheel out
of position by gearing the wheel e³ through the pinions a, b, provided on the swing
bracket s.
As shewn by Figures 4 and 5 Sheet 2 to provide for vertical adjustment or
change of the wheel the lower end of the quadrant may be slotted.
The invention further relates to an improved turret for carrying the tools on the
slide rests of lathes and to improved means for locking the same in position on the
slide.
Under the invention the turret A is, as shewn in front elevation by Figure 6 in
plan by Figure 7 and in vertical section by Figure 8 Sheet 2, made square so that
it may carry two, three or more tools and its base has two semicircular grooves B
made in it at right angles to each other.

page_text: The turret A is fitted upon a circular neck C projecting upwards from the slide
and the lock consists of a circular bar or bolt D which has a part cut out so that
when turned in one direction it presents a flat face at the base of the turret in
which position of the bolt the turret is unlocked and may be turned round to
present another tool. The outer end of the lock bar has a crank handle E applied
to it and in the side of the slide a pin F is fixed against which in turning the
lock D the ends of a semi-circular collar G upon it abut so preventing the lock
from moving too far in either direction.
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. In a screw cutting turning lathe the combination of parts constituting the
several arrangements of change mechanism hereinbefore described with reference
to the accompanying drawings.
2. In a turning lathe the combination of parts constituting the improved tool'
carrying turret herein before described with reference to the appended drawings.
Dated this 22nd day of March 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.