Improvements in or relating to Valves for Fluid-pressure Engines.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Valves for Fluid-pressure Engines.
A communication from ADRIEN PROLHAC, Junior, Merchant, of Allègre,
Republic of France.
I, Alfred JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be 28
follows:-
This invention relates to an improved steam-distribution valve and its
appurtenances. The valve is intended to rotate continuously.
The invention is essentially constituted by the combination of two principal
organs or parts:-a cylindrical valve-chamber mounted in the present instance on
the engine cylinder; and a circular disc rotatable inside the cylindrical chamber
and acting as a distributing organ.
The vertical end walls of the chamber are provided with openings joined by
short pipes to orifices or ports in the steam-cylinder face which are the openings
of the usual steam-passages of the said cylinder; the circular wall or shell of
the chamber is perforated, at two diametrically opposite points, with two
rectangular ports or openings by which a communication is afforded between the
interior of the chamber and two pipes; one of these ports, will act as steam-
admission port, while the other one will act as steam-exhaust port: consequently,
one pipe is put in connection with the steam-admission pipe, while the other pipe is
put in connection with the exhaust pipe.
As previously stated, within the chamber thus constructed, the circular disc fits
and rotates.
This disc is secured on one end of a shaft which traverses its centre, and is
carried by suitable bearings in the walls of the chamber, its other end, outside of
the chamber, is connected with mechanism by which its continuous rotation and
that of the disc is produced.
The disc, arranged in the hollow interior of the chamber, is provided with two
interrupted or segmental flanges one on each side of the disc; these are arranged
symmetrically, but diametrically opposite to one another, their equal and similar
circumferential extent exceeding the semi-circumference of the disc by the diameter
of one of the aforesaid ports, and their ends respectively extending past each
other by the same distance, so that at those two points, the two flanges have in
common a continuous cylindrical surface.
These latter surfaces are intended to work, in conjunction with the two aforesaid
ports, for steam admission to and exhaust from the chamber; these ports will
respectively be shut or open; shut for more and open for less than a semi-revolution
of the disc, by the continuous rotation of the said flanges in the manner herein-
after described. The axial length of the cylindrical segments may be equal to or
less than that of the interior space of the chamber (between the lateral walls
thereof); but in all cases it must be larger than the axial length of the ports. As
regards their width it must, as stated, be equal, in principle, to that of the
said ports.

page_text: Thus constituted and in combination with the distribution chamber, the
distributing disc forms, within the said chamber, two compartments entirely
distinct and having no communication with each other-assuming, of course, that
the cylindrical contact-surfaces of the disc and valve-chamber are perfectly fitted,
so as to allow the constant rotation of the former within the latter, under slight
friction, without permitting the passage of steam between the said contact-
surfaces.
The constitution of the improved system of steam distribution having thus been
set forth, its working is easily understood.
The
When the piston is at one end of the steam-cylinder i.e. at the end of its back-
stroke, the surfaces forming the longer cylindrical segments of the disc, exactly
close the ports of steam admission and exhaust, over their entire area.
continued rotation of the disc causes the part of the surface of the flange, in the
empty compartment, to partly uncover and open the steam admission port; while
the other part of the said port, in the empty compartment will remain closed by the
flange on that side during the semi-revolution thereof; whereas, simultaneously,
the steam-exhaust port, in the latter compartment, is partially uncovered or opened
by the flange, while its other part facing into the first-named compartment, remains
closed by the first-named flange during the semi-revolution of that flange in front
of it.
Under these conditions, the steam admitted by the admission pipe, passing
through the open and uncovered section of the port, fills the vacant space of the
valve-box, passes through the openings and short pipes, and thence through the
passages in the cylinder-wall, so as to act upon the rear surface of the piston and
drive it through its forward stroke; thereby the steam which, in the previous
stroke acted on the forward piston-surface, will be driven out at the other side and
fill the empty space, escaping through the open or uncovered half of the exhaust
passage, and finally out into the open air through the escape-pipe.
The above-described arrangements are suitable, in principle, for use with motors
working without expansion.
In practice, and more especially for single-cylinder motor the keying-on of the
distributor in relation to the two extreme positions of the piston must be effected
in such manner that closure of the admission and exhaust ports shall not be
absolutely completed at the moment of arrival of the piston in one or the other
extreme that is to ensure the actual function of steam admission and exhaust,
and consequently the working of the motor, whatever may be the position of the
piston at admission and cut-off.
For the application of the system of a continuous rotary distributing-valve to
motors working with expansion, the realisation of the determined degree of
expansion is effected by a variation either in the length of development of the
flanges of the disc; or in the dimensions of the surfaces of the coincident
segments thereof; or finally in the dimensions and positions of the steam admission
and exhaust ports; such variations in development, dimensions or positions being
naturally determined and combined, the ones in relation to the others, with a view
to the obtention of the required duration for the several operations of admission
expansion exhaust compression and lead.
The position of the improved valve-chest and gear may of course vary, in
relation to the steam-cylinder; but in all cases, it is well that it should be located
as close as possible thereto, so as to minimise, as far as possible and for reasons well
understood the spaces in the ports and passages.
Dated this 27th day of May 1895.
BOULT & WADE,
Agents for the Applicant.

page_text: Po valves for Fluid-pressure Engines.
A communication from ADRIEN PROLHAC, Junior, Merchant, of Allègre,
Republic of France.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 relates to an improved steam-distribution valve and its
appurtenances. The valve is intended to rotate continuously, and is illustrated by
way of example in the accompanying drawings as applied to an engine working
without expansion, although it is well suited to expansion engines.
In these drawings:
:-
Figure 1 shows in longitudinal central section a cylinder with the valve applied
thereto, the valve and valve-chest as well as the cylinder being in section.
Figure 2 is an end view of the apparatus shown in Figure 1 the valve-chest
being in vertical cross-section on the line X-Y of the said Figure 1.
Figure 3 is a plan view of the valve and valve-chest in section on the line X'-Y'
of Figure 2.
Figure 4 is a detail view showing separately in perspective the principal element
of this invention.
Figure 5 is a general diagram showing in plan a horizontal single-cylinder
engine, fitted with the improved valve and gear.
On examination of Figures 1, 2, 3 and 4 it will be easily seen that this invention
is essentially constituted by the combination of two principal organs or parts:-
a cylindrical valve-chamber A mounted in the present instance on the engine
cylinder B; and a circular disc C rotatable inside the cylindrical chamber A and
acting as a distributing organ.
The vertical end walls D E of the chamber A are provided with openings D¹ E'
joined by short pipes F G to orifices or ports in the steam-cylinder face which
are the openings of the usual steam-passages F¹ G' of the said cylinder; the
circular wall or shell of the chamber A is perforated at two diametrically opposite
points, with two rectangular ports or openings HI by which a communication is
afforded between the interior of the chamber A and two pipes H¹ I'; one of
these ports, say for instance H, will act as steam-admission port, while the other
one I, will act as steam-exhaust port; consequently the pipe H' is put in
connection with the steam-admission pipe, while the pipe 1 is put in connection
with the exhaust-pipe.
As previously stated, within the chamber A, thus constructed, the circular
disc C fits and rotates.
This disc C is secured on one end of a shaft J, which traverses its centre, and is
carried by suitable bearings in the walls D E of the chamber A, its other end,
outside of the chamber A, is connected with mechanism by which its continuous
rotation and that of the disc C is produced.
The disc C, arranged in the hollow interior of the chamber A, is provided
with two interrupted or segmental flanges K K¹, one on each side of the disc C;
these are arranged symmetrically, but diametrically opposite to one another, their
equal and similar circumferential extent exceeding the semi-circumference of the
disc by the diameter of one of the ports H I and their ends respectively extending
past each other by the same distance, so that at those two points, the two flanges
have in common a continuous cylindrical surface L or L'.
These latter surfaces are intended to work, in conjunction with the two ports HI,

page_text: for steam admission to and exhaust from the chamber A; these will respectively
be shut or open; shut for more and open for less than a semi-revolution of the
disc, by the continuous rotation of the said flanges K K in the manner herein-
after described. The length M, Figure 4 of the cylindrical segments at L L'
may be equal to or less than that of the interior space of the chamber A. (between
the lateral walls D and E thereof); but in all cases it must be larger than that, M¹
Figure 3 of the ports H 1. As regards their width N (Figure 4) it must as
stated, be equal, in principle, to that N', Figure 2 of the said ports H I.
Thus constituted and in combination with the distribution chamber A, the
distributing disc C forms, within the said chamber, two compartments 0 0¹,
entirely distinct and having no communication with each other-assuming, of
course, that the cylindrical contact-surfaces of the disc C and valve-chamber A
are perfectly fitted, so as to allow the constant rotation of the former within the
latter under slight friction, without permitting the passage of steam between the
said contact-surfaces
The constitution of the improved system of steam distribution having thus been
set forth, its working is easily understood.
The
When the piston P is at one end of the steam-cylinder B, as shown in Figure 1.
i.e., at the end of its back-stroke the position of the disc C in the valve-chamber A
will be that shown in Figures 1, 2, 3; in principle, in this position, the
surfaces L L forming the longer cylindrical segments of the disc C, exactly
close the ports H I of steam-admission and exhaust, over their entire area.
continued rotation of the disc C in the direction of the arrow (Figure 2) causes
the part of the surface L' of the flange K, in the empty compartment O, to partly
uncover and open the steam-admission port H; while the other part of the said
port H, in the empty compartment O' will remain closed by the flange K¹ on that
side during the semi-revolution thereof; whereas, simultaneously, the steam-
exhaust port I, in the same compartment O' is partially uncovered or opened by
the flange K' while its other part facing into the compartment O, remains closed
by the flange K during the semi-revolution of that flange in front of it.
Under these conditions, the steam admitted by the pipe H', passing through the
open and uncovered section of the port H, fills the vacant space O of the valve-box,
passes through the opening D' and short pipe F, and thence through the passage FI
in the cylinder-wall, so as to act upon the rear-surface of the piston P and drive it
through its forward stroke; thereby the steam which, in the previous stroke acted
on the forward piston-surface, will be driven out by the passage G¹ and passing by
the short pipe G enter and fill the empty space O escaping through the open or
uncovered half of the exhaust passage 1, and finally out into the open air through
the escape-pipe 1'.
The above described arrangements are suitable, in principle, for use with motors
working without expansion.
In practice, and more especially for single-cylinder motor the keying-on of
the distributor C in relation to the two extreme positions of the piston P must
be effected in such manner that closure of the admission and exhaust ports shall
not be absolutely completed at the moment of arrival of the piston in one or
the other extremes; that is to ensure the actual function of steam admission and
exhaust, and consequently the working of the motor, whatever may be the position
of the piston at admission and cut-off.
For the application of this system of a continuous rotary distributing-valve to
motors working with expansion, the realisation of the determined degree of
expansion is effected by a variation either in the length of development of the
flanges K K of the disc C; or in the dimensions of the surfaces of the coincident
segments L L thereof; or finally in the dimensions and positions of the steam
admission and exhaust ports HI; such variations in development, dimensions or
positions being naturally determined and combined, the ones in relation to the
others, with a view to the obtention of the required duration for the several
operations of admission expansion exhaust compression and lead.

page_text: The rotary motion of the distributing valve C may be brought about in any
suitable manner. In the engine illustrated by the diagram Figure 5 it is effectel
with the aid of a pair of mitre-wheels R R¹ carried, the one by the valve shaft J,
the other by the main crank-shaft of the engine.
The position of the improved valve-chest and gear may of course vary, in
relation to the steam-cylinder; but in all cases, it is well that it should be located
as close as possible thereto, so as to minimise, as far as possible and for reasons
well understood the spaces in the ports and passages.
Having now particularly described and ascertained the nature of this said inven-
tion as communicated to me by my foreign correspondent and in what manner
the same is to be performed, I declare that what I claim is :-
1. In a distributing-device for fluid-pressure engines the combination with a
valve-chamber such as A having in its walls ports by which the motive fluid is
supplied to and exhausted from it and passages for connecting the ends of the
chamber with the ends of an engine cylinder, of a rotatable partition such as C
which fits the interior of the valve-chamber and has at opposite sides interrupted
flanges substantially as and for the purpose described.
2. The combination with a distribution-device such as described of mechanism
for imparting continuous rotation to a flanged rotatable partition such as C
substantially as and for the purpose described.
3. The combination and arrangement of parts constituting a complete dis-
tribution-device for fluid-pressure engines substantially as and for the purpose
described and illustrated in the accompanying drawings.
Dated this 7th day of Fohwaz 1908
BOULT & WADE,
Agents for the Applicant.