Improvements in Lathes.
Year: 1896

page_text: Date of Application, 11th Jan., 1896
Complete Specification Left, 10th Oct., 1896-Accepted, 14th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Lathes.
I, HENRY LIEBERT, Ivy Villa, Victoria Park, Manchester, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in lathes and has for its objects, firstly, to
provide means whereby the chaser or tool is caused to return automatically at a quicker
speed than heretofore has been the case, secondly, to provide means whereby the
chaser or tool is withdrawn at the same time when causing the aforesaid return.
To this end I employ in addition to the ordinary screw, a second screw herein-
after termed the "return screw," suitably mounted and having a very quick thread.
Between the said screws 1 employ a double nut having corresponding threads and
adapted to be thrown alternately in and out of gear with the said screws and thus
cause the chaser or tool after being withdrawn to return automatically at a quicker
speed than if returned as heretofore by the ordinary screws. The said double nut is
carried by the part of the slide rest which over-hangs the bed of the lathe and is
rendered vertically adjustable thereon by having a stud engaging in an eccentric slot
formed in a disc fixed upon a short shaft and adapted to be partially rotated in the
said over-hanging part by means of a handle. Upon the said shaft is also fixed a
toothed segment in gear with a pinion fixed upon the end of a screwed spindle
which engages in a nut secured to the slide which carries the chaser or tool.
Thus when it is desired to effect the return movement of the chaser or tool the
aforesaid handle is turned sufficiently to throw the said double nut out gear with
the ordinary and into gear with the return screw which movement causes the said
segment and pinion to turn the aforesaid screwed spindle and thereby withdraw the
chaser or tool clear of the work.
After the return of the chaser or tool has thus been effected it is set by means of the
ordinary slide rest spindle as may be required and turning the aforesaid lever to its
former position the said double nut is thrown into gear with the ordinary screw and
out of gear with the return screw whilst in the meantime the chaser or tool is moved
in position for work.
Dated this 10th day of January 1896.
F. BOSSHARDT & Co.,
Agents to Applicant.
COMPLETE SPECIFICATION.
Improvements in Lathes.
I, HENRY LIEBERT, of Ivy Villa, Victoria Park, Manchester, in the County of
Lancaster, 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 :-
This invention relates to improvements in lathes for cutting screw threads and has
for its objects, firstly, to provide means whereby the chaser or tool is caused to return
automatically at a quicker speed than heretofore has been the case, secondly, to

page_text: provide means whereby the chaser or tool is withdrawn at the same time when
causing the aforesaid return.
And in order that my invention may be more fully understood I have caused to be
appended hereunto one sheet of drawings marked with letters of reference indicating
like parts in the various figures.
Figs. 1 & 2 are front views and Fig. 3 is an end view of the headstock end of a lathe
constructed in accordance with my invention, the slide rest being removed in
Figs. 1 & 3.
Fig. 4 is a sectional plan of the overhanging part of the slide rest.
Figs. 5 & 6 are cross sections of the slide rest and bed of the lathe at an enlarged
scale.
a is the bed, the headstock, c the feed screw or chasing hub, d, d' the slide rest,
and e.the slide which carries the chaser or tool.
In carrying out my invention and referring to the figures generally I employ in
addition to the ordinary feed screw or chasing hub c a second screw f having a very
quick thread, hereinafter termed the "return screw," suitably mounted, say in
bearings 9, 9, 9, secured to the bed a. Between the said screws I employ a double
nut c', ', having corresponding threads and adapted to be thrown alternately in and
out of gear with the screws c&f and thus cause the chaser or tool, after being with-
drawn, to return automatically at a quicker speed than if returned as heretofore by
the ordinary feed screw or chasing hub.
The said double nut is carried by the part d' of the slide rest which over-hangs the
lathe bed a and is rendered vertically adjustable thereon between plates h, h, Fig. 4,
as follows-
In the nut c', f', is secured a stud i engaging in an eccentric slot k formed in a
disc fixed upon a short shaft and adapted to be partially rotated in the over-
hanging part d. Upon the shaft or the disc k¹ is also fixed a handle and a
toothed segment m in gear with a pinion n fixed upon the end of a screwed spindle o
mounted in the slide rest part d². The spindle o is connected to the spindle p,
mounted in the slide e which carries the chaser or tool e, by another double nut o', p¹,
the spindle o engaging the nut part of and the spindle p the part pl.
Thus when it is desired to effect the return movement of the chaser or tool the
handle is turned sufficiently upwards to throw the nut part c' out of gear with the
ordinary feed screw or chasing hub c and the part finto gear with the return
screw This action not only returns the slide rest d, d' to the starting point but,
through the medium of the said segment m and pinion n, turns also the screwed
spindle o, and the latter through the nut o', p', withdraws the slide e and thus the
chaser or tool clear of the work.
After the return of the chaser or tool has thus been effected it is set by means of the
ordinary slide screw spindle p as may be required and turning the aforesaid lever
to its former position the double nut c', f'is thrown into gear with the ordinary
screw c and out of gear with the return screw f whilst in the meantime the chaser or
tool is moved in position for work.
The slide rest part d', see Figs. 2 & 5, I form with an arm q in which I mount
a shaft carrying a screw pinion s arranged in gear with the return screw f
whereby the slide rest d, d', can be returned by hand during the stoppage of the
lathe when 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 :-
1st. In lathes the employment of a return screw f and double nut c, f, in
combination with the ordinary feed screw or chasing hub c, the said double nut
being adapted to be alternately thrown in and out of gear with the said return
screw and feed screw or chasing hub, all substantially as and for the purpose set
forth.
2nd. In a lathe, constructed as specified in the preceding claim, the nut c', f¹

page_text: having a studi in combination with a disc k¹ formed with an eccentric slot k in
which the said stud engages and being adapted to partially rotate, all substantially
as and for the purpose set forth.
3rd. In a lathe, constructed as specified in the preceding claims, a segment m
adapted to rotate with the disc k, and impart rotary motion to a pinion n, which
is fixed upon a screwed spindle o mounted in the slide rest d, d', and engages in a.
nut o', p', carried by the screw. spindle p mounted in the chaser or tool slide e, all
substantially as and for the purpose set forth.
Dated this 9th day of October 1896
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.