IMPROVEMENTS IN THE CONSTRUCTION OF LATHES
Year: 1866

page_text: LETTERS PATENT to Thomas Greenwood, of Leeds, in the County of York,
Machine Maker, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF LATHES."
Sealed the 30th April 1867, and dated the 19th November 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Greenwood at
the Office of the Commissioners of Patents, with his Petition, on the
19th November 1866.
1, THOMAS GREENWOOD, of Leeds, in the County of York, Machine Maker,..
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF LATHES," to be as follows:-
The chief object of this Invention is to facilitate the "boring" of the tyres
of railway wheels, the object being to complete that operation without shifting
the work in the lathe. To this end I so mount and drive the chuck that is
to receive the tyre that the opposite sides and the inner face of the tyre may
be operated upon simultaneously by tools to which an automatic feed is
applied. Bolted to the bed of the lathe is an arch-shaped transverse frame
cast in two or more parts; in the inner face of this frame two V-grooves are
turned to receive and carry a ring formed with two corresponding V-projec-
tions on its periphery. Between these V" on the periphery of the ring is a
series of spur teeth which gear into a spur wheel carried by a shaft that has
its bearings on the bed of the lathe, and receives rotary motion from any.

page_text: suitable arrangement of driving gear. Through this means rotary motion is
communicated to the ring or annular spur wheel; the inner part of this
annular spur wheel is rebated or otherwise formed so as to receive rings or
chucks for the purpose of holding tyres of various sizes by suitable cramps and
set screws; on each side of the tyre thus mounted two slide rests are arranged
(four in all), which carry four cutting tools, two on each side of the chuck;
these rests receive a feed motion from an overhead rocking shaft in the
ordinary manner. When the tyre is intended to be filled with a wood interior
it will require to have a groove turned in each side thereof, into which the
flanges or rings which clasp the wood interior are to be fitted, and it is
desirable that both sides of the tyre should be turned before the tyre is
removed from the chuck. The arrangement above described does not admit
of this, but the turning can be completed without removing the tyre from the
chuck. The ratchet wheels which give the feed motion to the slide rests are
formed of screws or worms, on the periphery of which ratchet teeth are cut
for the feed pawls to take into, and by allowing the pawl to slide upon its
axle it is drawn forward by the thread of the ratchet wheel. Between the
coils of the thread of these ratchet wheels a ring formed in two parts, and
having a cam-like projection on one side is mounted and made adjustable
therein; the use of this adjustable cam is to bear the pawl above the teeth
of the ratchet in any part of the screw desirable; by this means several turns
of the feeding screw in the rest may be obtained, and the action of the pawl
upon the teeth of the ratchet arrested at any desired place, whereby the
constant attention of the attendant will be rendered unnecessary.
This arrangement is applicable to the automatic feed of turning tools
Generally
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Greenwood in the Great Seal Patent Office on the
18th May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GREENWOOD, of Leeds, in the County of York, Machine Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of November, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,

page_text: the said Thomas Greenwood, Her special licence that I, the said Thomas
Greenwood, my executors, administrators, and assigns, or such others as I,
the said Thomas Greenwood, my executors, administrators, and assigus, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF LATHES," upon the condition (amongst
others) that I, the said Thomas Greenwood, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Greenwood, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
The chief object of this Invention is to facilitate the "boring" of the tyres
of railway wheels by completing that operation without shifting the work in
the lathe; this I effect by an arrangement of lathe which will enable me to
present cutting tools to the opposite faces of the tyre, and also to its inner
periphery when mounted in the chuck by which it is rotated under the
cutting tools.
In the accompanying Drawings Fig. 1 is a side elevation, partly in section,
of the improved lathe; Fig. 2 is a plan view, also partly in section, and
Fig. 3 is a transverse section of the same taken in the line 1, 2, of Fig. 2.
A is the bed of the machine, and to it is firmly bolted an arched casting B,
which is made in two parts, and is intended to carry the chuck; to this end
the inside of the casting B is truly turned to receive a ring chuck C, which
is intended to carry and drive the tyre D. In the casting V-grooves are
turned to receive corresponding projections on the ring chuck C, and between
these projections the rings is provided with spur teeth c; fitted into the ring C
is a ring C* provided with radial clamping screws; in this ring C* the tyre D
is placed and fixed securely by means of the clamping screws. The chuck
thus constructed is driven by a spur pinion E which gears into the spur teeth
carried by the ring C; this spur pinion is keyed to a shaft F that has its
bearings in the bed of the lathe, and receives rotary motion from the main

page_text: driving shaft I through the spur gearing G, H; by this means a slow rotary
motion is communicated to the tyre when secured in the chuck. On each
side of the tyre thus mounted two slide rests K, K', K', and K' are arranged
(four in all) which carry four cutting tools suitably shaped for their respective
duties, two being on each side of the chuck; these rests receive a feed motion
from an overhead rocking shaft in the ordinary manner. When the tyre is
intended to be filled with a wood interior it will require to have a groove
turned in each side thereof into which the flanges or rings which clasp the
wood interior are to be fitted, and it is desirable that both sides of the tyre
should be turned before the tyre is removed from the chuck. The arrange-
ment of lathe shewn in Figures 1, 2, and 3 admits of this, as the turning can
be completed without removing the tyre from the chuck.
Instead of using the ordinary ratchet wheels and clicks or pawls for giving
the feed motion to the tools where an automatic feed is required that will
arrest the advance of the cutter on its reaching a given point, I employ the
feed shewn in Fig. 2 as applied to the slide rests K and K. On the periphery
of a worm or scroll 1 which is keyed to the ordinary feeding screw. 2 ratchet
teeth are formed to receive the driving pawl; upon this screw 2 swings a
forked frame 3 which carries a round cross bar, and on this bar the pawl 4
that drives the worm ratchet is free to slide in order that it may follow the
helical arrangement of the ratchet teeth. Between the coils of the thread of
these ratchet scrolls an adjustable cam-like projection is fitted for. throwing
the pawl out of action. It may be constructed in various ways, but the
simplest form is that shewn in the detached views Figures 4; in the helical
groove of the ratchet worm a rebated groove 5 is cut, and fitting into this
groove is the head 6 of a screw which receives a clamping nut 7 that binds it
firmly in place and forms the adjustable stop for arresting the action of the
pawl at the proper moment. pawl is made sufficiently wide to extend
beyond the teeth of the worm, and the nut or cam-like projection 7 is made
to stand somewhat higher than the ratchet teeth; this arrangement admits of
several turns of the feeding screw in the rest being obtained, and of the action
of the pawl upon the teeth of the ratchet being arrested on the tool arriving
at any desired point, the constant attention, therefore, of the attendant will be.
rendered unnecessary.
The
This arrangement I would here remark is applicable to the automatic feed
of turning tools generally, and may be beneficially employed where froin the
varieties of work performed the employment of fixed stops for throwing the
tool out of action are not admissible.
A modification of my improved lathe is shewn in sectional elevation at

page_text: Figures 5 and 6, the chief differences being that in this arrangement the chuck
is driven by a worm instead of a spur wheel, and that the chuck is somewhat
differently constructed. A is the bed of the machine; B is a casting in two
pieces firmly bolted to the bed A; the inside of this casting is truly turned to
receive the ring chuck C, which is fitted so as to rotate freely; in the slides or
bearings a is a worm wheel firmly fixed between the slides and actuated by the
worm 6 on the end of the shaft c; on the other end of this shaft are the driving
pulleys d and the ordinary gearing; the ring C is composed of two parts in
order that it may embrace an annular plate e, on the inner face of which a
scroll rib is formed which takes into grooves in four gripping blocks f,f; this
annular plate is capable of being moved partially round by means of a
pinion g which takes into spur teeth on the outside of the plate 6. When
this ring is turned partially round the gripping blocks are moved to or from
the centre of the lathe, thus gripping or releasing the tyre h; i, i, i, i, are four
plates provided with bolts and nuts for holding the tyre firmly against the
gripping blocks.
Having now set forth the nature of my Invention of "Improvements
in the Construction of Lathes," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim,-
First, the arrangement of parts, above described, for facilitating the
"boring" of the tyres of ralway wheels and for analogous uses.
And, secondly, the means above described for imparting the feed motion to
the slide rests of lathes and for arresting that motion..
In witness whereof, I, the said Thomas Greenwood, have hereunto set
my hand and seal, the Sixteenth day of May, in the year of our
Lord One thousand eight hundred and sixty-seven.