Improvements in Copying Lathes.
Year: 1895

page_text: Date of Application, 16th July, 1895-Accepted, 21st Sept., 1895
DOBIL LEIE DIEUITIVATION.
Improvements in Copying Lathes.
We, CARL GEORG DAHLGREN and JOHN HUGO SVENSSON, both of 13 Spann-
malsgatan, Stockholm, in the Kingdom of Sweden, Engineers 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:-
The present invention relates to the manner of arranging a movable profile
pattern in lathes in such a way, that the same by exact toothed gearing in the one
or other longitudinal direction of the lathe is moved forward with a speed which
depends on the feeding speed of the cutting-tool and so that the pattern will be
simply, and easily exchanged.
In the accompanying drawing
Figure 1 is a vertical section through the lathe,
Figure 2 shows a turned article and
Figure 3 the pattern used for turning the same.
a is a section through the article to be turned, b is the cutting-tool, arranged on
the cross-slide c, which, is worked by the counterweight / during the working, and
continually pressing the guiding tool g against the pattern e so that the tool is
moved towards and from the article a thus turning the same to correspond with the
profile of the pattern. The cross-slide c is in the ordinary way arranged on the
carriage or slide-rest d. This is provided with a rack n, worked by a toothed
wheel m, for moving the slide-rest in the longitudinal direction of the lathe.
By means of the wheel k, shaft j, worm wheel i and ordinary feed-wheels or belt
transmission, the wheel m is moved in the one or other direction. The pattern e,
the form of which is clearly shown in Figure 3, may be made of wood, or, if the
same is intended for a large number of articles it is made of metal, and is inserted
in the slide f, and is secured therein by screws h. This pattern is lengthened in
proportion to the length to be given to the piece to be turned. The slide is almost
as long as the longest pattern used and along its whole length provided with rack.
With this rack engages the toothed wheel which is secured on the same shaft as
the toothed wheel k. By this means the slide f during the rotation of the shaft is
fed forward with a speed, which is proportional to the feeding speed of the
slide-rest d, which proportion is determined by the size of the wheels k and l.
Instead of using the rack, secured to the slide-rest the lathe may be so arranged,
that a common feed screw is used for moving forward the slide-rest in which case
the wheel is driven by means of gearing from the feed-screw.
Instead of operating the cutting tool directly by means of the pattern as shown
on the drawing, the machine may be so arranged that the cutting-tool only moves
in the longitudinal direction of the lathe, and the pattern operated to move the
article nearer to or farther from the cutting tool. In this case the headstock and
the sliding-poppet must be arranged on a special movable bel, which by means of
lever mechanisms or the like may be moved transversely with relation to the frame
of the lathe to which the slides of the pattern and of the tool are secured.
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: :-
In automatic lathes in which the distance between the centre of the article to be
turned and the cutting-tool is by means of a pattern, shaped according to the form

page_text: of the article to be made, increased or reduced during the operation of turning, the
arrangement in which the pattern, by means of gearing from the feeding mechanism
of the cutting-tool, is during the operation of turning given a movement in its
longitudinal direction or in that of the lathe, with a speed that is a certain multiple
of the feeding speed of the cutting-tool in the longitudinal direction of the lathe,
the pattern being lengthened in proportion to the length to be given to the piece
to be turned.
Dated this 16th day of July 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.