AN IMPROVEMENT IN THE CONSTRUCTION OF SELF-ACTING LATHES."
Year: 1860

page_text: LETTERS PATENT to Sir Peter Fairbairn, Knight, and Joseph Burrow,
Mechanic, both of Leeds, in the County of York, for the Invention of
"AN IMPROVEMENT IN THE CONSTRUCTION OF SELF-ACTING LATHES."
PROVISIONAL SPECIFICATION left by the said Sir Peter Fairbairn and
Joseph Barrow at the Office of the Commissioners of Patents, with their
Petition, on the 24th July 1860.
We, Sir PETER FAIRBAIRN, Knight, and JOSEPH BARROW, Mechanic, both
of Leeds, in the County of York, do hereby declare the nature of the
said Invention for "AN IMPROVEMENT IN THE CONSTRUCTION OF SELF-ACTING
LATHES," to be as follows:-
In all slide and screw-cutting lathes that receive their traverse motion from
a screw it is desirable that the rate of the transverse motion shall be the
same as that of the traverse to prevent the necessity of the workman having
to shift the wheels to suit a change of work. In most lathes of the above
class the transverse motion is obtained by a worm wheel worked by the
traversing or guide screw. The slow motion thus obtained has therefore to be
recovered-say from 20 to 30 to -1, before the-transverse equals the rate of the
traverse motion.
This throws such a strain upon the worm wheel tooth

page_text: that sooner than move the slide it becomes a nut and slides the saddle, but
the tendency is overcome by powerfully locking the saddle to the bed. This
arrangement is however very unsatisfactory.
According to our Invention the saddle is connected to the traversing or
guide screw by clasp nuts which are made to disengage by a cam operated by
a handle. Upon the guide screw is placed a bevil wheel which forms a bearing
for the screw and is at rest when the saddle is being traversed, the screw
passing freely through the wheel. One end of the boss of this bevil whee!
is slightly coned and has a coned bush of brass, iron, or steel, fitted into it.
This bush is split along one side, and is forced in or out of the boss of the
bevil wheel by a worm and worm wheel segment acting upon a lever that
enters an annular groove in the split bush the whole being set in action by a
band wheel on the axle of the worm. The bevil wheel gears into another bevil
wheel, upon the shaft of which is keyed a pinion.
When required to work the surfacing motion the clasp nuts are dis-
engaged from the guide screw and the bush is forced into the coned-socket-of
the bevil wheel. From this bush being split it is free to close firmly on the
thread of the screw while fitting tight into the socket of the bevil wheel. It
will thus transmit motion from the screw to the bevil wheel and thence through
a train of gearing to the traverse screw of the slide, the saddle being at the
same time locked to the bed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Sir Peter Fairbairn and Joseph Barrow in the Great Seal
Patent Office on the 24th January 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BARROW, of Leeds, in the County of York, Mechanic, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of July, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Joseph Barrow and Sir Peter Fairbairn, Knight, deceased, Her special
license that we, the said Joseph Barrow and Sir Peter Fairbairn, our executors,
administrators, and assigns, or such others as we, the said Joseph Barrow and
Sir Peter Fairbairn, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-

page_text: after 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 "AN IMPROVEMENT
IN THE CONSTRUCTION OF SELF-ACTING LATHES," upon the condition (amongst
others) that we, the said Joseph Barrow and Sir Peter Fairbairn by an
instrument in writing under our hands and seals, or under the hand and
seal of one of us, should particularly describe and ascertain the nature of the
said Invention, 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 Joseph Barrow, do hereby declare
the nature of our said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the follow-
ing statement, reference being had to the Drawing hereunto annexed and to
the letters and figures marked thereon (that is to say):
:
This Invention relates to a novel arrangement for operating the traverse
slide of self-acting lathes whereby the workman may readily adapt the machine
to different kinds of work. In all slide and screw cutting lathes that receive
their traverse motion from a screw it is desirable that the rate of the trans-
verse motion shall be equal to that of the traverse or longitudinal motion.
In most lathes of the above class the transverse motion is obtained by a worm
wheel worked by the traversing or guide screw. The slow motion thus
obtained has to be multiplied say from twenty to thirty to one before the
This
transverse equals the rate of the traverse or longitudinal motion.
throws such a strain upon the teeth of the worm wheel in gear with the
traversing screw that sooner than move the slide it will act as a nut and slide
the saddle on which it is mounted. This tendency is however overcome by
powerfully locking the saddle to the bed of the lathe, but the arrangement is
not in all respects satisfactory.
In the accompanying Drawing, Fig. 1 is a plan view, Fig. 2 an end view,
and Fig. 3 a side view of so much of a lathe as will serve to explain the nature
of the present improvement.
A is the bed of the lathe; B, the saddle; and C, the transverse slide, upon
which are placed the ordinary slide rests; D is the guide or traversing screw
having a pair of clasp nuts a, a, which are made to disengage by a cam
operated by a handle, but which are not shewn in the Drawing. Upon the
guide screw D is placed a bevil wheel E having an elongated hollow boss
which turns in a bracket bearing on the under side of the saddle B. The

page_text: elongated boss of this wheel forms a bearing for the screw D, and it is at rest
when the saddle is being traversed to effect the "sliding" operation. One end
of the boss of the wheel E is slightly coned to receive a bush F of brass, iron,
or steel which fits into it as shewn in longitudinal and cross section at Figures 4
and 5. This bush is split along one side and is forced in or out of the boss of
the bevil wheel E, for the purpose of coupling the wheel with the screw D or
disengaging it therefrom, so that the wheel may rotate therewith or remain
quiescent according to the nature of the work in hand. Into the wheel E
gears a bevil wheel G, carried by a shaft G' which has its bearing in the
under side of the saddle B. Keyed to the shaft G' is a spur wheel H which
gears into an intermediate wheel I carried by an excentric boss on the side of
the saddle B. This wheel by gearing into a pinion K keyed on to the traversing
screw of the slide C, transmits rotary motion to that screw, which imparts the
transverse motion to the slide. In order to reverse this motion it is only
necessary to bring down the wheel I to the position shewn in red, and to
throw it into gear with a pinion L, carried by a quadrant arm L', having the
axis of the pinion K as its fulcrum. This pinion L being also in gear with
the pinion K, will transmit a reverse motion to the screw and cause it to move
the slide C in the reverse direction.
Supposing now it is desired to stop the "sliding" and work the "surfacing"
motion, the clasp nuts a, a, are first disengaged from the traversing or guide
screw D by means of the cam before mentioned, and the split bush F is forced
into the coned socket of the bevil wheel E. This operation is effected in the
following manner :-Affixed to the rear end of the split bush is a collar b,
having an annular groove into which takes the pin of a lever c. Keyed to
the fulcrum of this lever is a segment rack d, into which gears a worm e, on a
spindle, having its bearing in the end of the saddle, and carrying a hand wheel f.
By turning this hand wheel so that the lever c will be rocked inwards, the
bush F will be forced into the boss of the wheel E, and by reason of the
bush being split it will close firmly on the threads of the screw D, and at the
same time fit tightly into the boss of the wheel E; the screw and wheel will
therefore be temporarily locked together, and the wheel E will therefore be
caused to rotate at the same speed as the screw, and transmit that motion
through the gearing above described to the traversing screw of the slide C;
at the same the saddle will be securely locked to the bed of the lathe.
Having now set forth the nature of our Invention of "An Improvement
in the Construction of Self-acting Lathes," and explained the manner of carrying
the same into effect, I wish it to be understood that, under the above in

page_text: part recited Letters Patent, I claim obtaining the traverse motion for the
transverse slide from the guide or main traversing screw by the means above
described.
In witness whereof, I, the said Joseph Barrow, have hereunto set my
hand and seal, the Twenty-third day of January, in the year of
our Lord One thousand eight hundred and sixty-one.
JOSEPH BARROW. (L.S.)