Improvements in Turning-lathes.
Year: 1890

page_text: Date of Application, 14th May, 1890
Complete Specification Left, 12th Aug., 1890-Accepted, 20th Sept., 1890
TRUVIDIONAL DIVIFICATION.
Improvements in Turning-lathes.
I, GUSTAF ADOLF BRODIN, of Dalaro, in the Kingdom of Sweden, Engineer, do
hereby declare the nature of this invention to be as follows :-
:-
4
My invention relates to an improved lathe in which either oval or round articles or
articles oval at one part and less oval or round at other parts can be turned.
My improved lathe has either one or two headstocks, one of which is fixed to the
bed, while the other when used is movable thereon. The spindle of each headstock
carries a chuck or face-plate, which chucks or face-plates are adapted to move
simultaneously. Motion is imparted to the spindle of the fixed headstock by means
of a belt and pulley in the ordinary manner, whilst motion is communicated to the
spindle of the second headstock by means of a shaft and gearing.
.
In order to produce the oval or elliptical motion each headstock is provided with a
slotted ring adapted to be moved laterally in guides fixed to the headstock. On
the spindle of the headstock is a face-plate having guides in which works a slide on the
back of the chuck or face-plate proper. A pin on the latter carries a block adapted
to slide in the slot of the slotted ring, so that during the rotation of the chuck or face-
plate proper under the action of the face-plate on the spindle the said chuck or
face-plate proper will be caused to move under the action of the pin in the slot of the
slotted ring.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Turning-lathes.
I, GUSTAF ADOLF BRODIN, of Dalaro, in the Kingdom of Sweden, 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 an improved lathe in which either oval or round articles or
articles oval at one part and less oval or round at other parts can be turned.
My improved lathe has either one or two headstocks, one of which is fixed to
the bed, while the other when used is movable thereon. The spindle of each head-
stock carries a chuck or face-plate, which chucks or face-plates are adapted to
move simultaneously. Motion is imparted to the spindle of the fixed headstock by
means of a belt and pulley in the ordinary manner, whilst motion is communicated
to the spindle of the second headstock by means of a shaft and gearing.
In order to produce the oval or elliptical motion each headstock is provided with
a slotted ring adapted to be moved laterally in guides fixed to the headstock. On
the spindle of the headstock is a face-plate having guides in which works a slide
on the back of the chuck or face-plate proper. A pin on the latter carries a block
adapted to slide in the slot of the slotted ring.
In the accompanying drawing:
:-
Figure 1 is a front view of my improved lathe :
Figure 2 represents the bearing for the fixed headstock viewed from the inner
side; and,
Figure 3 represents the same viewed from the outer side the pitch lines of the
toothed-wheels or gearing being also shewn :
Figures 4 and 5 represent the slotted ring viewed from opposite sides; and,
Figures 6 and 7 are face and edge views respectively of the chuck disc or face-plate.
Similar letters of reference indicate corresponding parts in the several figures.
D

page_text: a, a¹ are the two headstocks. As the construction of these two headstocks is similar
I will only describe the headstock a, the corresponding parts of the headstock a¹ being
indicated by similar letters of reference with the addition of the figure 1. is the
spindle of the headstock a, and c a toothed-wheel (the pitch line of which in Figure 3
is also designated by the letter c), d is the slotted ring or disc (shewn in detail in
Figures 4 and 5) e being the slot thereof; the ring or disc d is also provided with a
guide corresponding to the guide g on the headstock, so that it can move laterally
relatively thereto. By means of a screw h, the slotted ring may be moved in a
horizontal direction, so that the slot will become more or less eccentric to the centre
of the spindle; is the face-plate having guides and fixed at its centre to the spindle.
(see Figures 6 and 7) it being adapted to rotate therewith; k is the chuck or face-
plate proper, and is the slide upon the chuck working on the guide-plate i, so that
the chuck can move relatively to the said guide-plate i, in addition to rotating there-
with. m is the pin on the chuck, placed near its circumference and shewn most
clearly in Figures 3, 6 and 7. The said pin passes through a slot in the guide-
plate. n is the oblong block on the end of the pin m, the said block being adapted to
work in the slot e of the slotted ring during the rotation of the chuck, thereby
causing the centre of the chuck to keep constantly at a radial distance from the slot
of the slotted ring equal to the constant distance between the centre of the chuck and
the pin m.
The toothed-wheel 'c gears with the pinion o fixed on the shaft p, which shaft
also carries a pinion o gearing with the wheel c¹ of the headstock a', whereby
motion is simultaneously transmitted to both headstocks. The pinion o' is connected
with the shaft p by a spline joint, so that it can move upon the shaft with the
headstock a¹.
If now the slotted-ring is moved laterally upon its guide, so that its centre is
moved, for instance, to s (see Figure 3) the block n and the pin m must, during
the rotation of the chuck disc, move in the slot e. As the centre of the chuck
disc moves upon the central longitudinal line of the slide i and at a constant
distance from the point in the slot e, where the pin m may at any moment be
located, this motion of the 'centre of the chuck disc creates an ellipse, the length
of both axes of which with relation to each other are dependent upon the distance
of the centre of the slotted ring from the 'centre of the spindle. In Figure 3 the
slide with the chuck disc is shewn inclined at an angle of 45%, the 'centre'of the
chuck disc being then at the point t. If both the slotted rings are adjusted 'at
equal distances on the same side of the spindle the ellipse will be the same along
the whole length of the piece being turned; otherwise the ellipse will become more
circular in form towards the chuck disc which has its slotted-ring least distant from
the centre of the spindle. If the slotted ring be located concentrically with the
spindle the ellipse will be graduated to a circle and, if both the slotted rings are
placed concentric with the spindles the whole piece being turned will have a
circular motion and will be turned into a cylindrical form as in an ordinary lathe.
If the slotted-rings be adjusted to opposite sides of the spindles the piece to be
turned will become 'oval at both ends and round in the middle or towards the chuck
disc, having its slotted-ring nearest the spindle.
The cutting-tool is manipulated as in an ordinary lathe by the hand and rests
against a slide-rest, or it can be screwed fast to a holder. These rests for the tools
being accessories varying in form are not shewn in the drawing, in order to avoid
complication.
The lathe may, if desired, be provided with only one headstock, in which case the
toothed-wheels and the intermediate shaft for transmitting 'motion to the other
headstock are not required.
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.. An oval-turning lathe, provided with two-headstocks having chucks facing each

page_text: other, the elliptical motion of each chuck being effected by a slotted ring in which
works a block fixed to the chuck, the said ring being fixed to a slide arranged on the
headstock under the spindle, the said slide being provided with an adjusting screw for
adjusting the ring or the slide, so that by properly adjusting the respective rings of
the headstocks, articles can be turned of different oval shapes at both ends or the
longitudinal axes of the ovals determined by both the headstocks may lie in different
planes.
2. An oval-turning lathe provided with only one headstock arranged as described in
claim 1, for the purpose set forth.
Dated the 12th day of August 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.