IMPROVEMENTS IN EXPANSION GEAR POR STEAM ENGINES
Year: 1865

page_text: LETTERS PATENT to William Fothergill Batho, of Birmingham, in the
County of Warwick, for the Invention of "IMPROVEMENTS IN EXPANSION
GEAR POR STEAM ENGINES."
Sealed the 8th August 1865, and dated the 14th February 1865.
PROVISIONAL SPECIFICATION left by the said William Fothergill Batho
at the Office of the Commissioners of Patents, with his Petition, on
the 14th February 1865.
I, WILLIAM FOTHERGILL BATHO, of Birmingham, in the County of War-
wick, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN EXPANSION GEAR FOR STEAM ENGINES," to be as follows:-
The object of this Invention is the ready adjustment of the slide or valve
for cutting off the steam from the cylinder according to the requirements of
the load whilst the engine is working. For this purpose I employ a loose
eccentric carrying a short shaft with a worm working into a worm wheel keyed
on the crank shaft, the said short shaft having a spur pinion or wheel
gearing into another wheel or pinion on an intermediate shaft which carries a

page_text: bevil pinion gearing into two bevil wheels running loose, one on the crank
shaft and the other on the boss of the eccentric. By arresting either of these
bevil wheels the eccentric is thrown backwards or forwards on the shaft, thus
regulating the opening and closing of the slide or valve; this operation can
be self-acting by means of the governor, or if desired, may be performed by
hand. The foregoing arrangement is applicable to the common slide valve,
but it may be found preferable to apply an extra valve and eccentric similar
to the one known as Myeres's.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Fothergill Batho in the Great Seal Patent Office on
the 14th August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
FOTHERGILL BATHO, of Birmingham, in the County of Warwick, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Fothergill Batho, Her special licence that I, the said
William Fothergill Batho, my executors, administrators, and assigns, or such
others as I, the said William Fothergill Batho, 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 EXPANSION GEAR FOR STEAM ENGINES," upon the con-
dition (amongst others) that I, the said William Fothergill Batho, 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 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 William Fothergill Batho, do hereby
declare the nature of my said Invention, and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by the
following statement (that is to say) :-
The object of this Invention is the ready adjustment of the slide or valve
for cutting off the steam from the cylinder according to the requirements of
the load whilst the engine is working. For this purpose I employ a loose
eccentric carrying a short shaft, having cut on it a worm working in a worm
wheel keyed on the crank shaft of the engine. To the said short shaft is
fixed a spur wheel or pinion gearing into another spur wheel or pinion fixed
on an intermediate shaft which carries a bevil pinion gearing into two bevil
wheels, one loose on the crank shaft and the other loose on the boss of the
eccentric.
This Invention will be clearly understood by referring to the figures and
letters on the accompanying Sheet of Drawings, in which Fig. 1 is a trans-
verse section, and Fig. 2 a longitudinal section of the foregoing improvements
in expansion gear for steam engines.
a represents the eccentric; b, the short shaft with a worm cut on it; c, the
worm wheel in which the worm is geared; d, the main or crank shaft of the
engine on which the eccentric is loose, and to which the worm wheel is keyed.
To the shaft 6 is fixed the spur wheel e, gearing into the spur wheel of fixed
to one end of the shaft g, carrying at its other end the bevil pinion h gearing
into the bevil wheels i, k, the wheel i being loose on the engine shaft d, and
the wheel loose on the boss of the eccentric, and the shafts b and g work in
bearings fixed to the eccentric. The eccentric a although loose on the
shaft d turns with it in consequence of being held by the worm wheel and
worm, and as the eccentric turns it carries with it the spur wheels and also
the bevil pinion and wheels. If one or the other of the bevil wheels i, k, be
arrested whilst the engine is in motion, the bevil pinion as it is being carried
round by the eccentric revolves in the teeth of the arrested wheel, and turns
the spur gearing and worm so as to shift the eccentric backwards or forwards
on the crank shaft, and thus regulate the movement of the slide or valve for
opening and closing the ports as required.
The operation of holding the bevil wheels may be effected by suitable hand
gearing so as to cut off the admission of steam to the cylinder at any part
of the stroke of the piston, or the governor may be made to operate on this
apparatus by means of friction brakes or otherwise, in order to regulate the
admission of steam to the cylinder according to the load on the engine.
Having now described the nature and particulars of my said Invention, and
the manner in which the same is to be performed, I desire it to be under-

page_text: stood that I claim the improvements in expansion gear for steam engines,
substantially as herein-before described and illustrated in the accompanying
Sheet of Drawings.
In witness whereof, 1, the said William Fothergill Batho, have hereunto
set my hand and seal, this First day of August, in the year of our
Lord One thousand eight hundred and sixty-five.
Sheet of Drawings.
In witness whereof, 1, the said William Fothergill Batho, have hereunto
set my hand and seal, this First day of August, in the year of our
Lord One thousand eight hundred and sixty-five.
W. F. BATHO. (L.S.)