Improvements in Lathes.
Year: 1897

page_text: Improvements in Lathes.
We, SIR ANDREW NOBLE, K.C.B., F.R.S., of Jesmond Dene House, Newcastle-
on-Tyne, and GEORGE STUART, of Elswick Works, Newcastle-on-Tyne, do hereby
declare the nature of this invention to be as follows:-
This invention relates to lathes for turning tapering articles and its object is
to automatically increase the speed of rotation of the work when the tool comes
to the smaller diameters of it.
For this purpose there are two pulleys on the countershaft one being larger
than the other.
On the mandril of the head stock are three pulleys, two loose and one fast.
The fast pulley is actuated by the belt from the large pulley on the countershaft,
but the belt also runs on the centre loose pulley. The belt on the small pulley
of the countershaft runs on the end loose pulley which is provided with an internal
pawl engaging with a ratchet wheel fixed to the mandril.
A fork is provided to work automatically as the tool is travelling.
At a certain diameter this fork shifts the high speed belt on to the fast pulley;
the mandril then begins to run at an increased speed, the slow pulley yielding
owing to the ratchet wheel over-running the pawl of the slow sheave.
10 dow of Navcumb 1907
A. NOBLE.
GEORGE STUART.
Improvements in Lathes
We, SIR ANDREW NOBLE, K.C.B., F.R.S., of Jesmond Dene House, Newcastle-
on-Tyne, and GEORGE STUART, of Elswick Works, Newcastle-on-Tyne, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to lathes for turning tapering articles and its object is
to automatically increase the speed of rotation of the work when the tool comes
to the smaller diameters of it.
Figure 1 is a side elevation, and Figure 2 a plan of a lathe embodying our
invention. Figure 3 is a local section on the line 3-3 Figures 1 and 2.
There are two pulleys A and B on the countershaft, B being larger than A.
On the mandril of the headstock are three pulleys C, D and E, two C and D

page_text: loose, and one E fast. The fast pulley E is actuated by the belt from the large
pulley B on the countershaft, but the belt also runs on the centre loose pulley D.
The belt on the small pulley A of the countershaft runs on the end loose pulley C
which is provided with an internal pawl F engaging with a ratchet wheel G
fixed to the mandril.
A fork H is provided to work automatically as the tool is travelling.
For this purpose the base of the fork which is pivotted at H₁ carries two
rollers H bearing on a shaped or cam surface travelling with the tool.
At a certain diameter this fork H shifts the high speed belt on to the fast
pulley E; the mandril then begins to run at an increased speed, the slow pulley C
yielding owing to the ratchet wheel G over-running the pawl F the slow sheave
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. The combination of pawl and ratchet or like mechanism tending constantly
to drive the mandril at a slow speed with faster driving mechanism put into action
by the travel of the tool.
2. The combination of two pulleys of different sizes on a countershaft, two
loose pulleys and a fixed pulley on the mandril, a belt driving one of the loose
pulleys from the smaller pulley, pawl and ratchet or like mechanism connecting
the loose pulley to the mandril, a belt driving either the other loose pulley or
the fast pulley from the larger pulley, and means actuated by the travel of the
tool for shifting the latter belt, from the loose to the fast pulley.
3. Mechanism for automatically increasing the speed of the work, substantially
as described and shown in the drawings.
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