IMPROVEMENTS IN ROTARY STEAM, AIR, OF GAS ENGINES
Year: 1875

page_text: LETTERS PATENT to John Garrett Tongue, of the Firm of Tongue
and Birkbeck, Patent Agents and Engineers, of 34, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN ROTARY STEAM, AIR, OF GAS ENGINES."
-A communication from abroad by M. Urbain Chauveau,
Engineer, of Paris, France.
Sealed the 15th February 1876, and dated the 23rd August 1875.
PROVISIONAL SPECIFICATION left by the said John Garrett Tongue
at the Office of the Commissioners of Patents, with his Petition,
on the 23rd August 1875.
I, JOHN GARRETT TONGUE, of the Firm of Tongue and Birkbeck,
Patent Agents and Engineers, of 34, Southampton Buildings, Chancery
Lane, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ROTARY STEAM, AIR, OR GAS
ENGINES," a communication to me from abroad by M. Urbain Chauveau,
Engineer, of Paris, France, to be as follows:-
The principle of this Invention is illustrated by the diagram, Figure 1
of the Drawings, hereunto annexed.

page_text: and piston rod b; k, fixed points of the eccentric; 1, supports or
bearings of the cccentrics; m, frame and brackets..
Figure 4 shows a vertical section taken on the line C, D, Figure 5;
and Figure 5 shows a longitudinal section taken on the line A, B,
Figure 4, of another arrangement of rotary engine of this character.
The cylinder is fixed at the end of a movable shaft on journals or
bearings, and the piston rod is carried by a stud or pin-joint of a crank
fixed on a movable shaft bearing on other journals conveniently placed.
With this arrangement motion may be given to both shafts. In these
two Figures the same letters refer to the same parts. a, cylinder;
b, circular slide valve; c, spring pressing the slide valve; d, crank
shaft; e, piston rod; f, shaft which carries or supports the cylinder;
g, ring for supporting the circular slide valve; h, inlet pipe; i, outlet
pipe; j, mouth for inlet of steam into the cylinder; k, frame and
brackets.
Various other arrangements may be employed in order to obtain the
same result; for example, it may be effected by placing friction rollers
at each end of a double piston rod in or upon a suitable central circle,
or by placing only one friction roller between two circles.
The method of regulating the admission of steam may be made in
any ordinary manner. The mechanical means by which this regulation
or distribution of steam is obtained are too numerous and too well
known to be mentioned here.
On the Drawings it will be seen that the regulation of steam is
obtained by means of a circular slide valve similar to those employed in
certain arrangements of oscillating engines.
As a whole the engine may represent arrangements of the most
varied nature, and may be constructed with one, two, or more cylinders
with fixed or variable expansion gear.
An engine of this character arranged with two equal cylinders
arranged at 180° has the advantage of producing an equilibrium so as
to revolve at any speed without producing any reaction on the frame or
foundation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Garrett Tongue in the Great Seal Patent
Office on the 23rd February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GARRETT TONGUE, of the Firm of Tongue and Birkbeck, Patent Agents
and Engineers, of 34, Southampton Building, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of August, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Garrett Tongue,
Her special license that I, the said John Garrett Tongue, my
executors, administrators, and assigns, or such others as I, the said
John Garrett Tongue, 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 ROTARY STEAM, AIR, OR GAS
ENGINES," a communication to me from abroad. by M. Urban Chauvean,
Engineer, of Paris, France, upon the condition (amongst others) that I,
the said John Garrett Tongue, 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 John Garrett Tongue, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
This Invention has for its object certain improvements in rotary
engines worked by steam, air, or gas, and in order that the same may

page_text: Three objects are of importance in carrying out this Invention,—

page_text: eccentric in order to reduce the friction. In these two Figures the same
letters refer to the same parts. a, cylinder; b, piston rod; c, eccentric;
d, circular slide valve; e, shaft which carries the cylinder; f, inlet pipe,
g, outlet pipe; h, friction rollers round the eccentric; i, cap or case
containing the friction rollers; j, axle connecting the cap or case and
piston rod b; k, fixed points of the eccentric; 1, supports or bearings of
the eccentrics; m, frame and brackets.
Figure 4 shows a vertical section taken on the line C, D, Figure 5;
and Figure 5 shows a longitudinal section taken on the line A, B,
Figure 4, of another arrangement of rotary engine of this character.
The cylinder is fixed at the end of a moveable shaft on journals or
bearings, and the piston rod is carried by a stud or pin joint of a crank
fixed on a moveable shaft, bearing on other journals conveniently
placed. With this arrangement motion may be given to both shafts.
In these two Figures the same letters refer to the same parts. a, cylinder;
b, circular slide valve; c, spring pressing the slide valve; d, crank
shaft; e, piston rod; f, shaft which carries or supports the cylinder;
g, ring for supporting the circular slide valve; h, inlet pipe; i, outlet
pipe j, mouth for inlet of steam into the cylinder; k, frame and
brackets.
Various other mechanical arrangements may be employed in order to
obtain the same result, for example, it may be effected by placing
friction rollers at each end of a double piston rod in or upon a suitable
central ring, or by placing only one friction roller between two rings.
The method of regulating the admission of steam may be made in
any ordinary manner. The mechanical means by which this regulation
or distribution of steam is effected are so well known that it is not
necessary to describe the same here.
On the Drawings it will be seen that the regulation of steam is
effected by means of a circular slide valve, similar to those employed.in
certain arrangements of oscillating engines.
As a whole the engine may represent arrangements of the most varied
nature, and may be constructed with one, two, or more cylinders with
fixed or variable expansion gear.
An engine of this character having two equal cylinders arranged at
180° has the advantage of producing an equilibrium, so as to revolve at
any speed without producing any reaction on the frame or foundation.

page_text: Having thus described the nature of the said Invention and the
manner of performing or carrying the same into practice, what I claim
under the above in part recited Letters Patent is,—
First. The construction of rotary engines with an ordinary cylinder
and piston, by which the movement of rotation results by the eccen-
tricity of the movement of rotation from a point of the piston rod and
cylinder, substantially in the manner herein-before described and
represented in the Drawings hereunto annexed.
Second. The various modifications of rotary engines acting, sub-
stantially on the same principle as that herein-before described.
In witness whereof, I, the said John Garrett Tongue, have
hercunto set my hand and seal, this Twenty-second day of
February, in the year of our Lord One thousand eight
hundred and seventy-six.
JOHN GARRETT TONGUE. (L.S.)