Improvements in and relating to Lathes and other Machine Tools.
Year: 1893

page_text: Date of Application, 13th Mar., 1893
Complete Specification Left, 13th Dec., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Lathes and other Machine Tools.
I, HENRY JESSE BAMFORD, of 85 Queen Victoria Street, in the City and
County of London, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to an improved construction of treble back gear for lathes
and other machine tools, the object being to obtain a greater variation in speed and
increased power.
According to my invention I take a lathe head fitted with the ordinary back gear,
the pinion on the back spindle of which is adapted to slide on the said spindle to put
it in and out of gear with the spur wheel on the main spindle carrying the face
plate. On to the frame of the lathe head is formed or fixed a bracket adapted to
carry a bearing in which is mounted a spindle on one end of which is fixed a pinion
adapted to engage with an internal spur wheel formed on or fixed to the back of
the face plate, and on the other end of which is fixed a spur wheel adapted to
engage with the pinion on the back spindle of the headstock when it is disengaged
with the spur wheel on the main spindle of the lathe carrying the face plate. The
bearing of the spindle carrying this spur pinion and spur wheel is mounted
eccentrically in the bracket carrying it, or it is otherwise given a cam motion, so
that by rotating it in the bracket the said pinion and wheel can be brought either
into, or out of, gear with the internal spur wheel formed on or fixed to the face
plate and the pinion on the back spindle respectively, to bring the third gear into
operation.
The relative sizes of the various spur wheels in the gear will obviously be
determined by the work the lathe is constructed, or intended, to do.
By this construction the lathe can be instantly changed from double to
treble gear.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Lathes and other Machine Tools.
I, HENRY JESSE BAMFORD, of 85 Queen Victoria Street, in the City and
County of London, 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 construction of treble back gear for lathes
and other machine tools, the object being to obtain the desired variation in speed
and power in the simplest and most reliable manner.
According to my invention I take a headstock fitted with the ordinary back gear,
and I mount the pinion on the back spindle which is adapted to gear with the spur
wheel on the main spindle carrying the face plate so that it can be slid in and out
of gear with the same spur wheel. On to the forward end of the headstock is
formed or fixed a bracket adapted to carry a bearing in which is mounted a spindle

page_text: on one end of which is fixed a pinion adapted to engage with an internal spur wheel
formed ou or fixed to the back of the face plate, and on the other end of which is
fixed a spur wheel adapted to engage with the pinion on the back spindle of the
headstock when it is disengaged with the spur wheel on the main spindle of the
lathe carrying the face plate. The bearing of the spindle carrying this spur
pinion and spur wheel is mounted eccentrically in the bracket carrying it, or it is
otherwise given a cam motion, so that by rotating it in the bracket the said pinion
and wheel can be brought either into, or out of, gear with the internal spur wheel
formed on or fixed to the face plate to bring the third gear into operation.
The relative sizes of the various spur wheels in the gear will obviously be
determined by the work the lathe is constructed, or intended, to do.
By this construction the lathe can be instantly changed from double to
treble gear.
In the accompanying drawing which forms part of this Specification,
Figure 1 is a view in side elevation of a headstock fitted with my invention, and
Figure 2 is a view in end elevation thereof.
In both views similar parts are designated by like letters of reference.
Referring to the drawing. A designates the headstock fitted with the ordinary
double gear consisting of the main spindle B, the cone C, the spur wheel D, the
spur pinion E, the back spindle F, the spur wheel G and the spur pinion H.
I mount the spur pinion H on a feather or key so that it can be slid in and out
of gear with the spur wheel D, and on the back of the face plate J I form or fix a
ring of teeth forming an internal spur wheel K. On to the forward end of the
headstock AI form or fix a bracket L carrying a bearing M in which is mounted
a spindle N carrying on one side of the said bearing a spur pinion O adapted
to gear with the internal spur wheel K on the back of the face plate J and carrying
on the other side of the bearing a spur wheel P with which the spur pinion H is
adapted to engage when it is slid out of engagement with the spur wheel D. The
spur pinion O is brought into engagement with or disengaged with the internal spur
wheel K by means of the well-known eccentric movement operated by a device
such as the lever D.
I wish it to be particularly understood that I do not limit myself to the precise
details of construction herein before described and illustrated by the accompanying
drawing, but that I hold myself at liberty to make such changes and alterations as
fairly fall within the spirit and scope of my invention.
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. The improved mechanism for giving a third variation in the speed of the
main spindle of a lathe, substantially as hereinbefore described and illustrated by
the accompanying drawing.
2. In late, the combination with a headstock fitted with the ordinary
double or back gear, of the bracket L formed on or fixed to the front end of the
headstock, of the bearing M carrying the spindle N, of the spur pinion O and spur
wheel P carried by the spindle N, and of the internal spur wheel K formed on or
fixed to the face plate J, all combined, arranged, and adapted to operate as and for
the purpose hereinbefore set forth.
Dated this 13th day of December 1893.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicant.