IMPROVEMENTS IN VALVES FOR DIRECT-ACTING ENGINES
Year: 1876

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents, 66,
Chancery Lane, in the County of Middlesex, Mechanical Draughtsman, for the
Invention of "IMPROVEMENTS IN VALVES FOR DIRECT-ACTING ENGINES." A com-
munication from abroad by Edward Purvis, of the City and State of New York,
United States of America.
ealed the 23rd September 1876, and dated the 18th April 18
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton at the
Office of the Commissioners of Patents on the 18th April 1876.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN VALVES FOR
DIRECT-ACTING ENGINES."
This Invention consists in a valve for direct-acting engines propelled by steam,
gas, or other vapour or fluid in which the motion of the engine piston is inade to
actuate the valve which controls said piston without the aid of valve gear, and
without the assistance of an auxiliary valve, by the direct pressure of the propelling
fluid on the piston controlling valve, as derived in part by the initial pressure of
said fluid on said valve, and in part by the spent fluid of the engine cylinder as
opposed to the reduced pressure of the exhaust. To this end the piston controlling
valve is constructed with a series of piston heads of different area and passages in
or through said valve operating in combination with a main inlet and with passages
leading to opposite ends of the engine cylinder, whereby a differential pressure is
obtained on the valve to throw or reverse it by the action of the propelling fluid
as the engine piston reaches the end of its stroke in opposite directions alternately.
The mere form of the valve may be variously changed, as also the arrangement
of the passages in or through it, likewise the disposition of the main inlet and of
the passages which connect with opposite ends of the engine cylinder, without
departing from the characteristic feature or principle of the Invention.

page_text: *SPECIFICATION in pursuance of the conditions of the Letters-Patent-filed by
the said Alfred Vincent Newton in the Great Seal Patent Office on the 17th
October 1876.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN VALVES FOR
DIRECT-ACTING ENGINES." A communication from abroad by Edward Purvis, of
the City and State of New York, United States of America.
This Invention consists in a valve for direct-acting engines propelled by steam,
gas, or other vapor or fluid, but which will here, to simplify explanation, be
described as propelled by steam, in which the motion of the engine piston is made
to actuate the valve which controls said piston without the aid of valve gear, and
without the assistance of an auxiliary valve, by the direct pressure of the propelling
fluid on the piston controlling valve, as derived in part by the initial pressure of
said fluid on said valve, and in part by the spent fluid of the engine cylinder, as
opposed to the reduced pressure of the exhaust. To this end the piston controlling
valve is constructed with a series of piston heads of different area and passages
in or through said valve, operating in combination with a main inlet and with pas-
sages leading to opposite ends of the engine cylinder, whereby a differential
pressure is obtained on the valve to throw or reverse it by the action of the.
propelling fluid as the engine piston reaches the end of its stroke in opposite
directions alternately. The mere form of the valve may be variously changed, as
also the arrangement of the passages in or through it, likewise the disposition
of the main inlet and of the passages which connect with opposite ends of the
engine cylinder, without departing from the characteristic feature, or principle of the
Invention.
Having thus explained the object and nature of the Invention, its description
will be proceeded with in reference to the accompanying Drawings.
Fig. 1 represents a longitudinal section of a steam engine cylinder with piston
therein, and one form of the piston controlling valve as arranged for operation in
parallel relation with the engine piston. Figures 2 and 3 are similar sections of the
same in part with the engine piston and its controlling valve in different positions.
Fig. 4 represents a transverse section of a steam engine cylinder with piston therein
through the centre of the valve chest, showing another form of the piston controlling
valve as arranged for operation in transverse relation with the engine piston. Fig. 5
is a similar view with the valve in a different position; and Fig. 6 a longitudinal
view of the engine cylinder with the valve box in section but having the valve
removed. The dotted line v, v, in Fig. 6, represents the plane in which the sections
Figures 4 and 5 are taken, and the arrows w, w, the direction in which the same
are viewed.
.
Referring in the first instance to Figures 1, 2, and 3 of the Drawings, A is the
cylinder of a direct acting steam engine, and B its reciprocating piston, C is the
valve box or chest of cylindrical construction on its interior and fitted with hollow
cylindrical heads or ends C, C. The steam is admitted to the valve box C by means
of a central inlet and a longitudinal connecting passage c, which opens at its
opposite ends into the valve box within the inner ends of the heads C³, C². The
ordinary or main induction and eduction passages d, d', which connect with opposite
ends of the engine cylinder communicate with the valve box or chest near its
centre. D is the main exhaust outlet from the valve chest, which outlet is also
central. The induction and eduction passages d, d', also communicate near their
inner ends with the valve chest, or rather with passages through the valve, by back-
wardly running passages or branches e, e', and further connect with the valve chest
by apertures, in rear, or outside of the passages e, e¹, which latter although
here referred to as separate passages or branches are virtually but extensions or
enlargements of the inner ends of the passages d, d', and may altogether be omitted
by enlarging said inner ends. Independent passages g, g', connect the interiors of
the hollow valve chest heads C1, C2, with the engine cylinder at points within the

page_text: range of the piston B as it completes its stroke in opposite directions, and so that
said piston uncovers the same as it approaches the ends of its stroke in either
direction. The valve, which is a cylindrical or piston one, is composed in part of
two main piston heads or cylindrical body portions E, E', constructed to work in
a free but close manner within the body or main portion of the chest C, and arranged
at a suitable distance apart so as to leave the main exhaust outlet Dalways exposed
between them, where said valve bodies or piston heads E, E', are connected by
a neck h, thus causing the space between the piston heads E, E¹, of the valve to
correspond with the exhaust cavity of a D shaped slide valve. Furthermore, the
valve which is now being described is also composed in part of two outer and
smaller heads or pistons F, F, arranged to work in close but free contact within
the hollow cylindrical valve chest heads C1, C, and connected with the main or
larger piston heads E, E, of the valve by necks i, i. These several pistons or piston
heads E, E, and F, F, of the valve control respectively the main induction and
eduction passages d, d, their branch passages, and the independent pas-
sages g, g. The branch passages e, e¹, connect either directly or by annular cavities
,, around the piston heads E, E', of the valve, with passages,, which project
longitudinally through the valve in reverse directions to the ducts d, d, into the
hollow valve chest heads C1, C2, in rear of the valves smaller piston heads F, F¹.
The operation is as follows:-Supposing the parts to be in the position represented
in Fig. 1, and the engine piston B to be moving in direction of the arrow x, the
steam entering by the inlet b escapes at the one end of the passage c between the'
piston heads E, F, and through the aperture f¹, which is uncovered by the piston
head E, and flowing along the passage d' continues to propel the piston B in the
direction of the arrow x. The live steain thus entering by the one end of the
passage c also passes by the branch e¹, annular cavity ¹, and longitudinal valve
duct to the right hand valve chest head C2 in rear of the small piston head F,
which then is free from covering the independent passage g that prior to the piston B
crossing it had been open to the exhaust in front of said piston and so exposed the
outside face of the larger piston head E also to the exhaust, thereby assisting the
throw of the valve to the right by the pressure of the steam on the greater area of the
piston head E¹ as against the pressure on the end of the piston head F of lesser area.
At the same time the other main induction and eduction passage d is open to the
exhaust between the piston heads E, E', of the valve, and the left hand valve chest
head Cis' similarly open to the exhaust in rear of the small piston. F1 by the
branch e, the annular cavity, and the longitudinal valve duct k³, the small piston
head F¹ then covering the independent passage gl, and the larger piston head E
closing the aperture and right hand outlet of the passage c.
When this is the
position of the parts then there is a differential pressure of the live steam entering
by the inlet b. against the back of the larger piston head E', as against the live
steam pressure on the outer end of the small piston head F, to hold the valve to the
right, until the engine piston B, travelling in direction of the arrow a uncovers,
as shown in Fig. 2, the independent passage g, when the spent steam of the
engine flows through said passage to the back of the piston head E, and counteracts
the pressure on the back of the piston head E¹, so that the live steam pressure on
back of the small piston head F starts the valve to the left. This action is continued
until the small piston head F closes the independent passage g, by which time the
duct will be open to the exhaust and the live steam will enter by the right hand
end of the steam passage c, and act upon the back of the piston head E to continue
the throw of the valve to the left, and to hold it there, as represented in Fig 3,
against the pressure of the steam entering by the duct d, passage e, annular cavity ²,
and longitudinal valve duct, to the back of the small piston head F¹, the other
small piston F being at the same time exposed to the exhaust by the valve duct *,
and passage e, and the outer face of the larger piston head E being also exposed
to the exhaust by the independent passage g¹. This change in the position of
the valve causes the engine piston to be reversed, and to continue its travel in
the direction of the arrow y (Fig. 3), until said piston passes the independent

page_text: passage g, when the valve, by the reversal of the passages or their exposure, is
thrown to the right again, substantially as described for its throw to the left. In-
this way or by these means the valve which controls the motion of the engine piston
is automatic, and operates by the difference of pressure on its respective heads, E, F,
and E, F, such action being due to the different areas of said heads, and to the
passages through the valve in conjunction with the fixed passages as herein-before
described.
Referring in the next instance to Figures 4, 5, and 6 of the Drawings, which show
a modified construction of the valve and of the passages connected with and con-
trolled by it, and which represent the valve as arranged for operation in transverse
relation with the engine piston. A is the engine cylinder, Bits piston, and C its
valve chest provided with hollow heads C³, C, as before. The valve itself is also
mainly of similar construction to that shewn in the previous Figures, and is ope-
rated in substantially the same manner, but its larger piston heads E, E¹, con-
nected by the neck h₁ are each duplicated or divided transversely, leaving a space
in between each connected division of them, into which space the longitudinal
passages, k, through the valve open, said passages extending as before through
the smaller end piston heads F, F¹, and the necks 2, i, which attach them to the
larger piston heads E, E'. In this valve the chest is supplied with steam by an
inlet b between the larger piston heads E, E¹, and connected with this inlet is a
longitudinal passage c, c, arranged to branch from either side of said general inlet
and controlled by the piston heads E, E¹, of the valve. The exhaust outlet D is
also made with a longitudinal extension branching from opposite sides of it and
which is likewise controlled by the piston heads E, E¹. The main induction and
eduction passages d, d¹, which connect the valve chest with opposite ends of the
engine cylinder have each duplicate openings into the valve chest at a suitable
distance apart in direction of the travel of the valve corresponding with the inner
end openings and branch passages ff, of the passages d, d', in the modification
herein first described. Furthermore, said induction and eduction passages also have
longitudinally and backwardly branching passages e, c¹, connected with them at
their one opening into the valve chest, as in the herein previously described modi-
fication. There are also independent passages g, g', controlled by the smaller piston
heads F, F, and connecting the hollow valve chest heads C1, C2, with the opposite
ends or portions of the engine cylinder.
The operation is the same as before. Thus in Fig. 4 the valve' has been thrown
to its extreme position to the right, and is held in said position by the pressure of
the live steam entering by the left-hand branch of the passage c and acting on the
outer face of the larger piston head El as against the pressure of steam on the outer
end of the smaller piston head F supplied from the engine cylinder by the pas-
sage, its branch e¹, and the longitudinal valve duct. When, however, the
engine piston B, which is supposed to be travelling in direction of the arrow z, has
passed the passage g it allows steam from behind said piston to act upon the outer
face of the larger piston head E, and by its counteracting action to the pressure on
the outer face of the other larger piston head E¹ the valve is started to the right,
as shewn in Fig. 5, by the pressure of the steam on the back of the smaller piston
head F until the piston head E uncovers the right-hand outlet of the live steam
passage c which admits live steam to the back of the piston head E to complete the
throw of the valve to the right, the piston head E' in the meantime closing the left-
hand outlet of the passage c and opening communication by the passage d, the
branch passage e, and the valve duct for steam to enter behind the smaller
piston head F. The motion of the engine piston having been thus reversed the
valve is held in its extreme position to the right till said piston passes the inde-
pendent passage g¹, when a like action of the valve as before, but in a reverse
direction, takes place. The hollow valve chest heads are alternately exhausted by
the valve ducts and being brought by the movement of the valve alternately
in communication with either induction and eduction passage d, d, open to the
exhaust and with the general exhaust outlet D, all substantially as herein-before
explained with reference to the first described modification.

page_text: To prevent misconception as to the action of the various passages or certain of
them, it may here be observed that in both of the modifications here shown of the
valve the passages e, el, are virtually a part of the induction and eduction pas-
sages d, d, and they might altogether be omitted by suitably enlarging or forming
the passages d, d, at such part, and in the form of valves shewn in Figures 1, 2,
and 3 the passages e, e¹, might be extended back to join the branch passages f. f',
thus making one continuous passage of the several passages d, e, f, or d¹, e¹, f.
In fact, so far as controlling the motion of the valve is concerned, the passages d, d',
night be enlarged or formed to altogether dispense with the separate passages or
branches e, e¹, and f, f¹.
Having now set forth the nature of the Invention of "Improvements in Valves
for Direct-acting Engines" as communicated to me by my foreign correspondent,
and explained the manner of carrying the same into effect, I wish it to be under-
stood that under the above in part recited Letters Patent I claim-'
First. A valve for controlling and reversing the piston of a direct-acting engine
composed of or provided with duplicate piston heads at its opposite ends of different
areas, and longitudinal ducts passing through the valve and connecting the inter-
mediate portion of the valve chest with the opposite ends thereof in combination
with fixed passages in the valve chest and engine cylinder organized substantially
as described, whereby the valve is automatically thrown in reverse directions alter-
nately by differential pressure of the propelling fluid on the piston heads of the
valve subject to the control of the engine piston, essentially as herein set forth.
Second. The combination with the engine cylinder A and its piston B of the
valve chest C with its hollow ends or heads C₁, C; the valve composed of piston
heads E, E, and F, F, of different areas as described; the longitudinal valve
ducts ; the main induction ports or passages d, d¹; the independent pas-
sages g, g; the steam inlet b with its longitudinal branch c, c; and the exhaust
duct or outlet D, substantially as specified.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto set my
hand and seal, the Seventeenth day of October, in the year of our Lord
One thousand eight hundred and seventy-six.
A. V. NEWTON. (L.S.)