IMPROVEMENTS IN THE CON- STRUCTION OF LATHES FOR BORING AND TURNING
Year: 1857

page_text: LETTERS PATENT to Hubert Pirotte, of Liége, in the Kingdom of
Belgium, Mechanist, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF LATHES FOR BORING AND TURNING."
Sealed the 26th January 1858, and dated the 15th August 1857.
PROVISIONAL SPECIFICATION left by the said Hubert Pirotte at the Office
of the Commissioners of Patents, with his Petition, on the 15th August
1857.
I, HUBERT PIROTTE, of Liége, in the Kingdom of Belgium, Mechanist, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF LATHES FOR BORING AND TURNING," to be as follows:-
My Invention of improvements in the construction of lathes for boring and
turning relates to an improved method of transmitting motion from any prime
mover to articles requiring to be turned or bored, and is chiefly applicable to
lathes in which the wheels for locomotive engines and carriages, the cylinders
of engines or pumps, and such like large articles are to be operated upon,
and for which purpose a slow but steady motion is required.
According to the ordinary method of driving lathes for this purpose, motion
is communicated from the motive power to the shaft (on which the chuck or
platform carrying the article to be turned is mounted) by means of bevil or
other toothed gearing; but this plan is attended with disadvantage, as although.
several sets of gearing may be employed in order to obtain as steady a motion

page_text: as possible, (and which complication of parts much increases the cost of con-
struction,) the articles produced were found to be defective from the vibrations
to which the platform, and consequently the article operated on, were liable.
The present Invention has for its object to obviate these disadvantages, and
to obtain a steady and uniform motion. For this purpose I convert the plat-
form carrying the article to be turned or bored into a worm wheel by cutting
teeth on its periphery, and communicate motion thereto by means of a worm
or enilless screw, mounted on a shaft, which is driven by the motive power
engine. This shaft may also be provided with a differential pulley, in order
to vary the speed thereof when desired.
If a quicker motion should be requisite, as for polishing and other light
work, the driving worm may be thrown out of gear, and motion commu-
nicated direct to the lathe shaft by means of a pulley on its outer extremity.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Hubert Pirotte in the Great Seal Patent Office on the 15th
February 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HUBERT
PIROTTE, of Liége, in the Kingdom of Belgium, Mechanist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of August, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Hubert Pirotte, Her special license that I, the said Hubert
Pirotte, my executors, administrators, and assigns, or such others as I, the said
Hubert Pirotte, my executors, administrators, and assigns, 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 FOR BORING AND TURNING," upon the condition
(amongst others) that I, the said Hubert Pirotte, by an instrument in writing
under my hand and seal, 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.

page_text: NOW KNOW YE, that I, the said Hubert Pirotte, 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 Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
My Invention of "Improvements in the Construction of Lathes for Boring
and Turning" relates to an improved method of transmitting motion from any
prime mover to articles requiring to be turned or bored, and is chiefly appli-
cable to lathes in which the wheels for locomotive engines and carriages,
the cylinders of engines or pumps, and such like large articles are to be
operated upon, and for which purpose a slow but steady motion is required.
According to the ordinary method of driving lathes for this purpose, motion
is communicated from the motive power to the shaft (on which the chuck or
platform carrying the article to be turned is mounted) by means of bevil or
other toothed gearing; but this plan is attended with disadvantage, as, although
several sets of gearing may be employed in order to obtain as steady a motion
as possible, (and which complication of parts much increases the cost of con-
struction,) the articles produced are found to be defective, from the vibrations
to which the platform, and consequently the article operated on (or in the case
of boring the cutting tool), are liable.
The present Invention has for its object to obviate these disadvantages, and
to obtain a steady and uniform motion. For this purpose I convert the plat-
form carrying the articles to be turned or bored into a worm wheel, by cutting
teeth on its periphery, and I communicate motion thereto by means of a worm
or endless screw, mounted on a shaft, which is driven by the engine or other
motive power. This shaft may also be provided with a differential pulley, in
order to vary the speed thereof when desired.
If a quicker motion be required, as for polishing and other light work,
the driving worm may be thrown out of gear, and motion communicated
direct to the lathe shaft by means of a pulley on its outer extremity.
The Figures in Sheets I. and II. of the accompanying Drawings represent a
lathe constructed on my improved principle, adapted for boring cylinders of
from one foot to nine feet in diameter, and for turning or boring articles with
the platform or chuck of as large a diameter as twelve feet.
Fig. 1 is a side elevation of this lathe; Fig. 2, a plan view; and Fig. 3,
an end elevation, taken at that end where the platform is situate. A, A,
are the traverses or framing of the lathe on which the various working
parts are mounted; B is the circular platform or chuck, having worm teeth
cut on its periphery, and taking into a worn or screw D by which it is

page_text: driven; E is a differential pulley, having nine different speeds, which receives
motion direct from the motive engine, and transmits it to the shaft F, upon
which both the pulley E and endless screw D are keyed; G is a fixed
standard, having a cylindrical hole made through it, a portion of which near
the platform is countersunk, by which means the shaft which carries the
platform is strengthened at that part where there is most danger of breaking.
K is the moveable standard, which has also a moveable axis or point, for
the purpose of facilitating the adjustment of the article to be operated upon.
m, m, is an arrangement of gearing which may be employed when it is required
to drive the lathe at a higher speed, either for polishing or boring holes of
small diameter.
The Figures in Sheets III. and IV. represent another arrangement suitable
for turning the wheels of locomotives, even of the largest known diameter.
Fig. 4 is a side elevation; Fig. 5, a plan view; and Fig. 6 an end view of the
machine. A, A, is the framing, on which the various operating parts are
mounted; B, B', are two circular platforms or chucks, having worm teeth on
their peripheries; C, C¹, are two slide rests, which may be moved in a direction
either parallel with or perpendicular to the axis of the lathe by means of the
winch handles m and their endless screws. The upper parts of these rests are
also jointed to the lower parts in such manner that they may be set at any
desired angle, and fixed in that position by means of set screws p, p. D is a
fixed standard or support, provided with a shaft, upon which is mounted a
pulley d. This pulley is made to communicate with another pulley d¹³, (see the
plan view Fig. 5) when the lathe is required to be driven at a high speed; E is
the moveable standard, the shaft of which is provided with a hollow shaft for
the purpose of facilitating the backward or forward motion of the holding
point; L, L, L", are the endless screws, with their shafts, brackets, and other
accessories; K (Fig. 5) is a differential pulley, with nine speeds, which by
means of its shaft K' drives the bevil gearing K", through which motion is
communicated to the worms L which drive the worm wheels or rotating
chucks B, B¹.
The advantages of this improved construction of lathe are as follows,
vizt:-
Firstly, great simplification in the arrangement, by means of which an
economy of about cent. per cent. in the cost of construction is effected.
Secondly, almost direct transmission of motion, and consequently a dimi-
nution of more than half the friction.
Thirdly, a much more uniform and continuous motion, and the absence of
the vibrations caused by the transmission of motion by means of gearing.

page_text: Having now described my Invention of "Improvements in the Construction
of Lathes for Boring and Turning, and having explained the means of carry-
ing the same into effect, I would observe that what I claim as new in the
above-described machinery and desire to secure by Letters Patent, as afore-
said, is the mode herein shewn and described, or any mere modification
thereof, of actuating the rotating chucks of lathes or turning or boring
machines.
In witness whereof, I, the said Hubert Pirotte, have hereunto set my
hand and seal, the Tenth day of February, in the year of our Lord
One thousand eight hundred and fifty-eight.
HUBERT PIROTTE. (L.S.)
Witness,
E. VAN HOORN.