IMPROVEMENTS IN PRIME MOVERS Å ALLTER BY STEAM OR OTHER FLOID PRESSURE."
Year: 1880

page_text: LETTERS PATENT to George Wilkinson, of Manchester, in the County of
Lancaster, Engineer, for an Invention of "IMPROVEMENTS IN PRIME MOVERS
Å ALLTER BY STEAM OR OTHER FLOID PRESSURE."
PROVISIONAL SPECIFICATION left by the said George Wilkinson at the
Office of the Commissioners of Patents on the 29th October 1880.
GEORGE WILKINSON, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN PRIME MOVERS ACTUATED BY STEAM OR OTHER FLUID
PRESSURE."
My Invention relates principally to prime movers actuated by steam, and has
for its principal object to obtain a high speed of piston, and thereby to increase the
relative powers of the engines. To this end I employ two pistons fitted to work in
one oscillating cylinder, and so acting as that the moving parts balance each other
in their various positions. The said cylinder is provided with a cover at each end,
and each of the two piston rods work in one of the said covers. Each piston rod
takes hold of a separate crank, or of the pin of a crank, and the two crank shafts
are provided with pinions which gear with a central wheel which is secured to a
main shaft. The said crank shafts may also be provided with fly-wheels. The
said central wheels maintain the relation of the two sets of moving parts to each
other in all their movements, so that the two pistons move outwardly and inwardly
in unison. The arrangements for controlling the admission and emission of the
steam to and from the cylinder may be varied. In one arrangement a curved
valve face is formed upon the cylinder, the centre of generation of the curve being
the axis of oscillation of the cylinder. Three ports communicating with the centre
and ends of the cylinder are formed in the said face, and in a block which is fitted
to be in contact with the said face are formed two induction and two eduction
ports, which are respectively in communication with the steam and exhaust pipes.
In some cases I provide the said block with a valve box, in which is a cut-off
valve which is worked from a rocking shaft which receives motion from the
cylinder, or which is otherwise suitably worked. The said block is maintained in
contact with the valve face on the cylinder by means of a spring, or by other
suitable means. In place of one cylinder, two cylinders formed in one piece or
attached together may be used, and in some cases an engine may be provided with
more than two pistons. The power generated may be obtained from the central
shaft for slow speeds, or from the crank shaft for quick speeds, or from both, or
the gearing may be so proportioned as to obtain the required speed for the central
shaft. My Invention is also applicable in the construction of engines actuated
otherwise than by steam, as for example, of hydraulic prime movers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Wilkinson in the Great Seal Patent Office on the 28th April
1881.
GEORGE WILKINSON, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN PRIME MOVERS ACTUATED BY STEAM OR OTHER FLUID
PRESSURE."
My Invention relates principally to prime movers actuated by steam, and has for
its principal object to obtain a high speed of piston, and thereby to increase the
relative powers of the engines. To this end I employ two pistons fitted to work in
one oscillating cylinder, and so acting as that the moving parts balance each other
in their various positions. The said cylinder is provided with a cover at each end,
and each of the two piston rods work in one of the said covers. Each piston rod
takes hold of a separate crank, or of the pin of a crank, and the two crank shafts
are provided with pinions which gear with a central wheel which is secured to a
main shaft. The said crank shafts may also be provided with fly-wheels. The
said central wheels maintain the relation of the two sets of moving parts to each
other in all their movements, so that the two pistons move outwardly and inwardly
in unison. The arrangements for controlling the admission and emission of the
steam to and from the cylinder may be varied.
And in order that my Invention may be fully understood, I have attached
hereunto a Sheet of Drawings made to a scale of about two inches to the foot.
Referring to the said Drawings, Fig. 1 is a sectional clevation, and Fig. 2 a plan of
an engine constructed in accordance with my Invention. In the said Figs. A is the
steam cylinder; B, B, are two crank shafts, and C is a central shaft which is
coupled with line shafting, or from which the power generated is transmitted to the
machinery to be actuated in any ordinary or suitable manner.
The said cylinder
is formed with trunnions a, which are mounted in bearings b, so that the cylinder
can oscillate upon an axis which is centrally situated as relative to the length and
diameter of the cylinder. The cylinder is fitted with two pistons c, c, and with two
piston-rods d, d, which pass out through glands at the ends of the cylinders, and
are directly connected with crank pins e, e, which are fixed in heavy discs f,f,
which take the places of crank arms, and act as fly-wheels for the shafts B, B;
upon each of the said shafts is keyed a spur pinion g, which gears with a spur
wheel, which is keyed upon the central shaft C. All of the shafts are fitted to
revolve in suitable bearings, which in the example are mounted upon or formed in
a foundation framing i, which may be of any suitable form and construction. The
method of gearing together the three shafts, and the proportions of the gearing may
also be varied. The steam cylinder may be provided with any suitable arrange.
ments for controlling the admission and emission of steam. In the example the
cylinder is formed with a curved valve face which is concentric with the axis of
oscillation, and works in contact with a fixed valve chest k, which is formed with
suitable ports, and is supplied with steam by means of a pipe . Within the said
valve chest a cut off valve m is fitted to work, and may receive motion from a
rocking shaft actuated by the cylinder, or may receive motion in any other suitable
manner. It will be seen that the reciprocating parts are always moving in opposite
directions, and that they balance each other in all parts of the revolutions of the
crank shafts, the result being that the engine is capable of being run at a high
speed, and as a consequence of developing a high duty comparatively to the
diameter of the cylinder. Owing to the balanced action of the pistons, all strain
upon the cylinder trunnions is obviated, whilst the position and mode of driving
the pinions has a like effect in relieving the main shaft, the consequence being that
smaller bearings may be employed, and a reduction in friction effected. The

page_text: vibration usually attendant upon high speed is also prevented. Instead of deriving
the generated power from the central shaft C, it may be directly obtained from the
crank shafts B, especially in cases wherein high velocities are required. In the
example the steam cylinder is cast in one piece, but if preferred, it may be formed
in two parts bolted or secured together, and also in some cases an engine may be
provided with more than one double cylinder, and therefore with more than two
pistons and cranks. Although I have specially referred to steam as the propelling
medium, I do not confine myself thereto, as my Invention is applicable in the
construction of engines otherwise actuated, such for example as hydraulic engines.
Having now fully set forth and indicated the nature of my said Invention, and
the manner in which the same may be carried into effect, I would have it to be
understood in conclusion that I claim,-
First. The combination of parts forming a prime mover, arranged. and acting
substantially as set forth and indicated hereinbefore and in and by the accom-
panying Drawings.
Secondly. The oscillating double cylinder fitted with two pistons moving in
opposite directions, and the two crank shafts connected together by means of an
intermediate shaft and gearing, substantially as and for the purpose or purposes set
forth and indicated.
•
And, Lastly. The employment in prime movers of oscillating cylinders with
piston rods actuating two crank shafts geared together so as to revolve in unison
the piston rod or rods and connected parts actuating one crank shaft always
moving in an opposite direction to to the piston rod or rods which actuate the other
crank, substantially as set forth and indicated.
In witness whereof, I, the said George Wilkinson, have hereunto set my
hand and seal, this Twenty-sixth day of April, in the year of our Lord
One thousand eight hundred and eighty-one.
Signed, sealed, and delivered
in the presence of
ARTHUR LEDGER,
(Clerk to Edward K. Dutton),
41, John Dalton St.,
Manchester,
(Agent for the Patentee).
GEORGE WILKINSON. (L.S.)