Improvements in Fluid Pressure Engines, applicable also as Pumps.
Year: 1891

page_text: Date of Application, 9th Feb.,
1891
Complete Specification Left, 18th Mar., 1891-Accepted, 18th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Fluid Pressure Engines, applicable also as Pumps.
I, CHARLES HORATIO BRAIN, of 67, Park Street, Southwark, in the County of
London, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to Improvements in Fluid Pressure Engines,
applicable also as Pumps, of the kind described in the Specification of Letters
Patent granted to A. Rigg, dated 16th May 1885, No. 6047, and in which the
cylinders are formed with bosses mounted to revolve upon a central stud or
bearing, the pistons of the said cylinders being connected to a wheel or disc
mounted to rotate about an axis out of line with that about which the cylinders
rotate. In such engines the ports or passages that serve alternately for inlet
and exhaust of motive fluid (hereinafter referred to as steam) to the cylinders, are
formed in the bosses of the cylinders which work in conjunction with a side cheek
or boss (hereinafter called for distinction a valve cheek) formed with corresponding
inlet and exhaust passages and having a faced side. The bosses of the cylinders
rotate between and in contact with the valve cheek and a flange or plate which is
fixed to the pin or bearing upon which the cylinders rotate and which can be
adjusted endways by a screw nut to set up the bosses against each other and one of
them against the valve cheek. This arrangement is however open to serious
objection in practice because during the working of the engine, the bosses are
forced in a direction away from the valve cheek and against the fixed flange or
plate which being consequently subjected to excessive friction soon becomes worn
away to such an extent that the bosses will move away from the valve cheek so as
to leave a space between that cheek and the adjacent boss and through which space
steam will pass direct from the steam inlet passage to the exhaust passage without
entering the cylinder, thus rendering the engine useless.
Now the object of this invention is to obviate this disadvantage for which purpose
I cause fluid for example steam, to enter a space or chamber formed between the
outside of the boss farthest from the valve cheek, and a disc or piston that fits a
chamber or short cylinder formed in the said boss and is carried by a tube that
passes through the stud or bearing about which the cylinders revolve, the arrange-
ment being such that when the engine is started, steam enters the said space or
chamber and causes the bosses to be forced together and against the valve cheek
with a pressure a little in excess of that tending to force the said bosses away from
the said valve cheek. By this means the bosses are constantly and automatically
kept up to the valve cheek and the said bosses are kept nearly in equilibrium
between the valve cheek and the disc or piston notwithstanding variations in the
pressure of steam supplied to the engine from time to time. Suitable means such
as packing rings are provided to prevent the escape of steam from the said
steam space or chamber. The disc or piston and tube may or may not be arranged
to revolve.
Dated this 9th day of February 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in Fluid Pressure Engines, applicable also as Pumps.
I, CHARLES HORATIO BRAIN, of 67, Park Street, Southwark, in the County of
London, Engineer, do hereby declare the nature of this invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
This invention has reference to Improvements in Fluid Pressure Engines,
applicable also as Pumps, of the kind described in the Specification of Letters
Patent granted to A. Rigg, dated 16th May 1885, No. 6047, and in which the
cylinders are formed with bosses mounted to revolve upon a central stud or bearing,
the pistons of the said cylinders being connected to a wheel or disc mounted to
rotate about an axis out of line with that about which the cylinders rotate.
In such engines the ports or passages that serve alternately for inlet and exhaust
of motive fluid (hereinafter referred to as steam) to the cylinders, are formed
in the bosses of the cylinders which work in conjunction with a side cheek or
boss (constituting, and hereinafter referred to as the valve) formed with corre-
sponding inlet and exhaust passages and having a faced side. The bosses of
the cylinders rotate between the valve and a flange or plate which is fixed to
the pin or bearing upon which the cylinders rotate and which can be adjusted
endways by a screw nut to set up the bosses against each other and one of them
against the valve. This arrangement is, however, open to serious objection in
practice, because, during the working of the engine, the bosses are forced in a
direction away from the valve and against the fixed flange or plate which being
consequently subjected to excessive friction soon becomes worn away to such an
extent that the bosses will move away from the valve so as to leave a space between
it and the adjacent boss through which space steam will pass direct from the steam
inlet passage to the exhaust passage without entering the cylinder, thus rendering
the engine useless.
Now the object of this invention is to obviate this disadvantage; for which
purpose I cause fluid, for example steam, to enter a space or chamber formed
between the outside of the boss farthest from the valve, and a disc or piston that
fits a chamber or short cylinder formed in the said boss, and is carried by a tube
that passes through the stud or bearing about which the cylinders revolve, the
arrangement being such that when the engine is started, steam will enter the said
space or chamber and cause the bosses to be forced together and against the valve
with a pressure a little in excess of that tending to force the said bosses away from
the valve. By this means the bosses are constantly and automatically kept up to
the valve, and are kept nearly in equilibrium between it and the disc or piston,
notwithstanding variations in the pressure of steam supplied to the engine from time
to time. Suitable means, such as packing rings, are provided to prevent the escape
of steam from the said steam space or chamber. The disc or piston and tube may
or may not be arranged to revolve.
The accompanying drawing shows in vertical section so much of a four cylinder
engine of the kind referred to as is necessary to illustrate the application thereto of
my invention.
1, 2, 3 and 4 are the bosses of the four cylinders; only parts of two of these
cylinders, viz. 1" and 3" are shown. 5 is the stud or bearing about which the
cylinders revolve. 6 is a sleeve surrounding the stud or bearing and fixed to the
boss 1 so as to revolve therewith. Upon this sleeve the other bosses oscillate
during the working of the engine. 7 is the valve; it is formed with the usual steam
inlet and exhaust passages, and against its inner faced side the boss 1 rotates.
8, 8 are the passages in the bosses; each of these passages serves alternately for
inlet and exhaust of steam to its respective cylinder. 9, 9, are packing rings between
the valve and adjacent boss 1 and between the adjacent bosses. The foregoing
parts are constructed and arranged in the manner usual in engines of the kind

page_text: referred to. 10 is a disc or piston; it fits within a short cylinder 11 formed at the
outer side of the boss 4; this short cylinder forms in conjunction with the boss and
the disc or piston, an annular steam space or chamber 12. The disc or piston 10 is
fixed upon a tube 13 that passes through the stud or bearing 5, and is in commu-
nication at one end by holes 14 with the steam space or chamber 12, and at the
other end by a bonnet or chamber 15 and pipe 16 with the steam supply pipe or
conduit of the engine. 16* are nuts that limit the movement of the tube 13 and
disc or piston 10 to the right. 17 is a packing ring located between the disc or
piston 10 and the boss 4. This ring, when the engine is in action, is pressed by the
steam in the space or chamber 12 against the face of the boss 4 and against the
rim 10% of the disc or piston 10. 18 is a packing ring between the disc 10 and
cylinder 11. 19 is packing material, for example asbestos, to form a tight joint
between the stud or bearing 5 and the tube 13. 20 is a gland that automatically
compresses the packing material 19 against a ring 20, by the action upon it of the
steam admitted to the space or chamber 12. The area of the boss 4 subjected to
pressure of steam within the space or chamber 12, is such that when the engine is
working the pressure of steam tending to force the bosses towards the valve 7 is
in excess of that tending to drive them in the opposite direction and which is due to
the pressure on the valve 7 of the steam within the passages 8 of the respective
cylinders. The difference in the two pressures may be a predetermined one such
as to prevent escape of steam between the several surfaces in contact, whilst also
obviating excessive friction and consequent wear of such surfaces. I prefer as
hereinbefore stated, to place the tube 13 in communication with the pipe or passage
that supplies steam to the engine cylinders, as then the difference between the two
pressures mentioned will remain constant notwithstanding variations in the pressure
of the steam supplied from time to time to the engine.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In a fluid pressure engine (or pump) of the kind referred to, subjecting the
bosses of the cylinders to the pressure of fluid acting in an opposite direction to and
of greater amount than that tending to move the bosses away from the valve, for
the purpose specified.
2. Constructing an engine (or pump) of the kind herein before referred to, with a
closed steam space or chamber one side of which is formed by that cylinder boss
which is farthest from the valve, the said space or chamber being in communication
with a source of fluid pressure, substantially as hereinbefore described for the
purpose specified.
3. My hereinabove described improvements in engines of the kind referred to.
Dated this 17th day of March 1891
Dated this 17th day of March 1891
C. H. BRAIN.
W. Lloyd Wise,
Per F. J. B.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.