IMPROVEMENTS IN OSCILLATING CYLINDER ENGINES
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
" IMPROVEMENTS IN OSCILLATING CYLINDER ENGINES."-A communication
from abroad by Albert Schmid, of Zurich, Switzerland, Engineer.
Sealed the 2nd June 1874, and dated the 10th December 1873.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 10th December 1873.
22
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN OSCILLATING CYLINDER ENGINES,' a com-
munication to me from abroad by Albert Schmid, of Zurich, Switzerland,
Engineer, to be as follows:-
This Invention relates to certain improvements in oscillating cylinder
engines, whereby such engines whether actuated by steam or compressed
air are enabled to work expansively with a single cylinder and without
the use of separate expansion slides or valves.

page_text: In carrying out this Invention it is proposed to employ a single
cylinder oscillating on trunnions, as is well understood, such cylinder
containing a trunk piston, the annular area of which on one side is.
considerably less than the full area of the opposite side of the piston.
The outer end of the trunk or piston rod which works through a stuffing
box in one end of the cylinder forms the crank pin bearing. The
cylinder is formed on its under side with a convex curved port face, the
curve of which is struck from the centre line of the trunnions as
described in the Specification of Letters Patent granted to me on behalf
of the said Albert Schmid, No. 906, 1871, and rests upon a corresponding
concave bed, also as described in the said Specification. The steam inlet
pipe opens into a chamber in which a port is made opening through the
concave bed.
Two steam passages leading respectively to opposite ends of the
cylinder are cast in the said cylinder, and have ports or openings made
in the convex port face. Fresh steam from the boiler first enters the
end of the cylinder which contains the reduced or annular area of the
piston, the corresponding steam passage being brought by the oscillation
of the cylinder over the steam port in the concave bed. By the time
the steam has done its work in that end of the cylinder and forced the
piston to the opposite end the position of the cylinder will have been so
altered as to shut off the steam inlet port and to bring the ports of the
two steam passages into communication with each other through a con-
necting passage and ports cast in the concave bed, thus bringing for the
moment one end of the cylinder into free communication with the other
end. The steam therefore that has first impelled the piston by its
pressure on the annular area thereof passes into the opposite end of the
cylinder and operates by its expansion upon the larger or full area of
the piston to drive it back. This movement brings the port opposite to
an exhaust port in concave bed and allows of the escape or exhaust of
the steam either into the atmosphere or into a condenser, as is well
understood.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 9th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of December, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, my executors,
administrators, or 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 OSCILLATING
CYLINDER ENGINES," a communication to me from abroad by Albert
Schmid, of Zurich, Switzerland, Engineer, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or admi-
nistrators, 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.
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:

page_text: air are enabled to work expansively with a single cylinder and without
the use of separate expansion slides or valves.
In carrying out this Invention it is proposed to employ a single
cylinder oscillating on trunnions, as is well understood, such cylinder
containing a trunk piston, the annular area of which on one side is
considerably less than the full area of the opposite side of the piston.
The outer end of the trunk or piston rod which works through a stuffing
box in one end of the cylinder forms the crank pin bearing. The
cylinder is formed on its under side with a convex curved port face, the
curve of which is struck from the centre line of the trunnions as
described in the Specification of Letters Patent granted to me on behalf
of the said Albert Schmid, No. 706/71, and rests upon a corresponding
concave bed, also as described in the said Specification. The steam
inlet pipe opens into a chamber in which a port is made opening through
the concave bed.
Two steam passages leading respectively to opposite ends of the
cylinder are cast in the said cylinder, and have ports or openings made
in the convex port face. Fresh steam from the boiler first enters the
end of the cylinder which contains the reduced or annular area of the
piston, the corresponding steam passage being brought by the oscillation
of the cylinders over the steam port in the concave bed. By the time
the steam has done its work in that end of the cylinder and forced the
piston to the opposite end the position of the cylinder will have been so
altered as to shut off the steam inlet port and to bring the ports of the
two steam passages into communication with each other through a con-
necting passage and ports cast in the concave bed, thus bringing for the
moment one end of the cylinder into free communication with the other
end. The steam therefore that has just impelled the piston by its
pressure on the annular area thereof passes into the opposite end of the
cylinder and operates by its expansion upon the larger or full area of the
piston to drive it back. This movement brings the front opposite to an
exhaust port in concave bed, and allows of the escape or exhaust of the
stream either into the atmosphere or into a condenser, as is well under-
stood.

page_text: purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the corresponding Figures.
Figure 1 represents a plan of my improved oscillating engine ;
Figure 2, a side elevation of the same; and Figure 3, a side sectional
elevation of the same on line 1, 2, in Figure 1.
A represents a single cylinder oscillating on trunnions a, a, similar to
those of ordinary oscillating cylinders. In the cylinder A works the
piston B cast or formed with a trunk b, which works through a stuffing
box and gland C on the front end of the cylinder A, and terminates at
its outer end in a bearing or connecting head D fitted with a cap E and
connected directly with the crank pin F, which communicates motion to
the shaft G, working in bearings H, H, bolted to or cast on the bed
plate I of the engine.
The cylinder A is formed on its under side with a raised portion K,
having a convex port face k, which is struck or radiates from the centre
line trunnions a, a, (as described in the Letters Patent granted to me on
behalf of the said Albert Schmid, No. 706/",) and rests on or moves in
contact with the corresponding face of a concave bed (also as described
in the said Specification) forming a portion of the bed plate I of the
engine. Lis the steam inlet pipe opening into a chamber formed in the .
concave bed, and provided in the face of the latter with a port or
opening 1. x and z are passages formed in the raised portion K of the
cylinder A, and leading respectively from ports or openings in the
opposite ends of the cylinder A to similar openings in the convex port
face k, as shown; y is a connecting passage formed in the concave bed,
and having ports or openings in the same for bringing the passages and
ports x and y into communication with each other when required, as
hereafter described. M is the exhaust passage leading from a port in
the face of the concave bed to the condenser or atmosphere.
The manner in which this engine works is as follows:-The cylinder
and its appendages being in the position shown on the Drawing, viz.,
with the ports 1 and x partly opposite to or in communication with each
other, steam from the boiler (or compressed air, as the case may be,)
enters the inlet chamber L, and passing through the port or opening 1
therein and through the passage and ports x enters the cylinder A upon

page_text: the annular or trunk side of the piston B, and pressing upon the latter
forces it to the opposite or under end of the cylinder A, when a slight
continued movement of the crank past its dead centre (owing to the
momentum of the engine) the cylinder A is moved or partly turned upon
its trunnions a, a, so as to quickly bring the passage and ports a into
communication with the connecting passage and ports y, and conse-
quently with the passage and ports at the opposite or under end of the
cylinder A. The steam (or compressed air, as the case may be,) now
escapes from the annular or trunk side of the piston B through the
passage x along the passage y, and through the passage z to the opposite
or hinder side of the piston B, the full area of which being greater than
the partial or annular area of its trunk side, the steam in consequence
forces the piston B with a preponderating pressure, and by the expansion
back to the front end of the cylinder A until the completion of the
stroke, when the passage and ports z are brought into communication
with the exhaust port and passages M, and the expanded steam passes.
away through the same to the condenser or atmosphere. At the same
time fresh steam from the boiler again enters on the annular or trunk
side of the piston B, and the above operation is repeated, a continuous
rotation being thereby imparted to the shaft G.
By this Invention the use of separate expansion slides or valves is
dispensed with, and the working parts of the engine are reduced to a
minimum.
Having now described and particularly ascertained the nature of the
said Invention, and in what manner the same is or may be used
or carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the In-
vention secured to me by the herein-before in part recited Letters
Patent is,-
First. The arrangement and construction of the ports and passages in
the single oscillating cylinder of an engine worked expansively in
combination with the ports and passages formed in a fixed bed, substan-
tially as and for the purpose herein-before described and illustrated by
my accompanying Drawings.
Second. The application of a trunk piston formed at its trunk end
with a connecting head or bearing to an oscillating cylinder, substantially

page_text: as and for the purpose herein-before described and illustrated by my
accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Ninth day of June,
One thousand eight hundred and seventy-four.
J. HENRY JOHNSON. (L.S.)