Improvements in and connected with Equilibrated Valves for Steam and other Engines.
Year: 1890

page_text: Date of Application, 22nd Dec., 1890
Complete Specification Left, 22nd Sept., 1891-Accepted, 7th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in and connected with Equilibrated Valves for Steam
and other Engines.
I, JAMES FREW of 5 Greenhill, Dunaskin, Ayrshire, Engineer do hereby
declare the nature of this invention to be as follows:-
My invention is a development or improvement upon that class of equilibrated
valve for steam and other engines or motors wherein the live steam, air, gas or
other fluid is admitted into the cavity, which, in ordinary slide valves, constitutes
the exhaust port (the usual exhaust port thus constituting the steam or other fluid
inlet, and the usual inlet port constituting the exhaust) although it is to be
understood that the inlet steam may be admitted to the cavity of the valve in any
of the usual methods if so desired.
I will now proceed to describe my invention as applied, under various modifi-
cations, to steam engine valves, reference being had to the accompanying sheets of
drawings whereon :-
Fig. 1. shows in section an equilibrated slide valve, with valve chest and cylinder
ports.
Fig. 2. is a plan view of valve as at Fig. 1, with the valve piston removed.
Fig. 3. is a plan of the piston of the valve removed from Fig. 2.
Fig. 4. shows in section a modified form of valve with adjacent parts broken
away.
Fig. 5. is a plan of the piston of the valve Fig. 4.
Fig. 6. is a plan of the valve, Fig. 4. with the piston removed.
Fig. 7. is a section of a valve piston.
Fig. 8. is a plan of the valve piston Fig. 7.
Figs. 9. 10. and 11. are sections of different constructions of valve.
Fig. 12. is a sectional plan on the line A-B Fig. 10.
Figs. 13. and 14 are sections of valves.
Fig. 15. shows, in section, a cylinder with two valves fitted thereon, one at
each end.
Fig. 16. shows in section a double valve arrangement for an engine with two
cylinders A. A side by side.
Fig. 17. is a view of the upper valve box D, Fig. 16, looking towards the ports
of the cylinder A¹.
Fig. 18. shows, in section, part of a cylinder with valve and ports and
passages.
Fig. 19. is a plan of the valve Fig. 18 with pistons removed.
Fig. 20. is a cross section of the valve on the line E-F, Fig. 19.
Figs. 21. & 22. are sections of valves.
Fig. 23. is a plan of the valve Fig. 21.
Fig. 24. shows, in section, a double piston valve with ports & passages.
Fig. 25. is a plan of Fig. 24 with cover K¹ removed.
Fig. 26. shows, in section, a rotating or partially rotating balanced valve with
accessory parts.
Fig. 27. is a plan of the piston of valve Fig. 26.
Fig. 28. is a sectional plan of valve and ports, on the line G-H. Fig. 26, with
biston of valve removed.
On the drawings the same reference letters wherever repeated indicate similar or
ike parts.
Referring to Figs. 1. 2. & 3;-A is the cylinder. B the steam inlet port, which
s fitted with a cut off valve C of the "Corliss type." D is the the sliding box or

page_text: .
cup of the valve for the admission and release of steam to the cylinder A, through
the cylinder ports E & F. The dotted lines at G, G' indicate the position of valve
box Ď when steam is being admitted to the cylinder through the port E & being
exhausted from the back of piston through the port F. As will be seen more
particularly at Fig. 2. the valve box D is made of a hollow cup shape with the
oblong induction port H cut in the face, the back part of valve box D being
completely cut away. If the valve piston P was removed, as at Fig. 2, the steam
filling up the interior of the valve box D would only press down on the portions
not cut out, marked on the plan Fig. 2. The piston P, which is fitted into the
interior of the valve box or cup D, has two or other number of spring rings I,
shown to a larger scale at Fig. 4, which hold themselves steam tight against the
interior face of the wall D' of the valve box D. J, J', are spiral springs which
are fitted in recesses J in the piston P. Instead of using spiral springs, however,
any other suitable form of spring may be employed and if desired three or other
number of springs may be fitted in the valve. The object of using the springs, J, J,
is to press the piston P, and, at the same time, the valve box D each against their
respective working faces in the steam chest K with sufficient force to overcome the
friction caused by the piston, P, and spring rings I bearing against the inner face
or wall-Dof the valve box D. The steam of its own pressure has the tendency to
separate the piston, P, and valve box D from one another and so cause-the-valve.
to work tight against its bearings. The piston P which may be flanged over
at P1, P2, (Figs. 1 & 3) has, on its upper side, or back, bearing strips L which may
be arranged in rectangular form as shown at Fig. 3. These strips which bear
steam tight against the casing cover K, as shown, enclose, a cavity or space L¹.
Steam passes from the induction port H, cut out of the valve box D, through a
balance hole or opening M, in the piston P, to the cavity or steam space L', at the
-top of said piston. The balance hole M may be either tapered, as shown, or be
tapered the reverse way, or be a straight channel without taper right through; -or-
there may be two or more small channels or equivalent made in the piston in lieu
of the balance hole M. By locking steam in the cavity-or-space-L!-which is of an
arca. equal to the area of the cylindrical part, enclosed-by-the-wall-Dof_the_
valve D, a true balance is maintained by the exposure of two equal areas or-sides to
the opposing action of the steam. Consequently the only upward or outward
pressure on the piston, P, is that due to the action of the springs, J, J', so long as
the bearing strips L keep steam tight against the casing cover K. The small
opening at the bottom of the balance hole M only admits of a small quantity of
steam passing through to the cavity or space L, and, therefore, should-the strips .L.
wear down and leak, very little steam would be lost. The top of the balance
hole M may be cup shaped or hollowed out as shown at M N is a groove
running round valve piston P which serves as a trap space for any steam that
might leak past the first or lower ring I. On the plan view of the piston P. (Fig. 3)
four relief holes N', communicating between the groove trap N and the cavity or
space Lare shown. These holes N1 carry off any leakage of steam which may pass
into the trap N and thus replaces any leakage from the cavity or space L¹ over the
bearing strips I should this occur. The holes N may or may not be used as
desired. O is the usual hoop or ring passing round the valve. O is the valve
spindle or stem. 02 the usual collar bush. O³trap space. The bearing bush 0,
or usual packing gland is or may be as shown screwed hard up against collar 02
O is a small hole leading from trap space 03-into-the-smoke box (by means of a
pipe, not shown); or into the trap, drain, or the atmosphere. The hole O relieves
the bearing bush O' from any back pressure of steam greater than the pressure of
the atmosphere. Instead of having the bush 0' screwed up against collar O³, a
bearing bush driven into chest K may be used as shown in the small view to left of
Fig. 1. M, Fig. 2 is the steam inlet branch and M³ the exhaust outlet. C' is the
spindle for operating the cut off valve C.
Figs. 4, 5 and 6 show an oblong piston P as fitted into the valve cup or box D.
The valve in this case is very similar in construction to that at Figs. 1, 2 and 3 the

page_text: only difference being that the valve cup D is recessed out at right angles so that
the sectional view of the side walls D and face of the cup or box show like
two 's. The cut out part H of the face of the valve is rectangular as shown in
plan at Fig. 6. The piston P is, in this instance, made with the bearing strips I
raised all round the edge of the piston as shown at Fig. 5. The slips, I, are, in
this case, pressed against inner face of the walls D' of the valve box D by means of
plate springs R. The springs J. J', are, in this case, dispensed with, the upward
pressure of the steam being sufficient to keep strips L close against the cover K'.
The holes N are in this view shown in full lines.
Figs. 7.& 8. show a piston P of cylindrical form, the only difference in its
construction from the hereinbefore described pistons being that it has no escape or
leakage holes N¹ and that the bearing face is made in the form of a circular raised
flange-rim L on the top of the piston. The slips, I, in the piston may also be, as
shown, dispensed with the slips being inserted instead in grooves in the valve
box D. It is shown with cavities 2 for springs the same as in Fig. 1.
Fig. 9 shows a valve with a piston P made with a recess P₁ around its upper side
into which are fitted loose bearing strips L enclosing the balancing steam space or
cavity L'. P is packing at the underside of the strips L. The bearing slips 1
are pressed against the inner face of the wall D' of the box or cup D by the
springs R which may be plate springs, as shown, or be spiral springs. The upper
slips I, are, by spiral or other springs R³, pressed tight against the inner face of
the bearing strips L. It will be seen that the strips L press in this instance, both
against the inner face of the wall D of the box or cup D and against steam chest
cover K. Plate springs J, Jare shown as being used in lieu of spiral springs as
at Fig. 1. The slips I may or may not be used as desired.
Figs. 10 and 12 show a modified construction of valve. In this case the piston P
which is circular and very thin is fitted on top of a solid part D3 which is hollowed
out at D' so as to form a trick port as shown. The channels N¹ may, in this case,
as indicated in dotted lines, communicate with the trick port D*. Passages D³ for
steam are made through the valve. These passages, which communicate with the
steam space D and the space D', are or may be of rectangular formation as shown.
The steam in the spaces D and L' balance the piston P. This view is merely
shown to illustrate a method of making my improved valve with a trick port.
Fig. 11 shows a somewhat similar valve to Figs. 10 and 12, the only difference
being that the part D3 is made solid throughout with a steam passage D³ in centre,
instead of having a trick port D and passages D' as at Figs. 10 and 12.
Fig. 13 shows a valve somewhat similar to that at Fig. 9 with the piston I made
with a recess around its upper part. Into this recess a ring L is fitted so as to bear
against the casing cover K. The piston in this view has the balance hole M made
with the taper towards the top instead of the bottom as in the preceding figures.
With this arrangement the ring L can be renewed at any time without total
renewal of the piston or valve box D.
Fig. 14 differs from the foregoing in having the valve box or cup D fitted with a
split ring L³. The ring having a recessed groove L4 around it, into which is fitted
a ring, or it may be rings, R which bear steam tight against the walls of the box
or cup D. The piston P is also in this view shown tapered like a cone and as being
fitted into the inside of ring L³. The top edge of the piston, where it is fitted just
a moving fit into the inside of ring L³, is shown at b. The lower flanged or bent
over edge c of the piston bears, as shown, against the lower edge of the ring L³.
This arrangement shows the piston as without rings in itself but with a balance
hole M and cavities for springs J, J. The valve in this case although having a
limited measure of escape is only partially balanced (d showing the unbalanced
area around top of ring. The ring 13 is tapered off as much as possible consistent
with leaving a sufficient working surface, as shown, to reduce the unbalanced area.
By removing the piston, P, and leaving the ring L³ with its bearing surface made
to the inside of ring, as shown in dotted lines at e, the valve would allow an escape
or leakage limited only by the amount of steam entering at inlet port instead of

page_text: the limited escape permitted by the piston P with balance hole M. If the piston
was removed as suggested the steam inlet could be through the casing cover Kor
through the inlet port B. The ring L³ in this case would have a spring or springs
fitted between its lower rim and the bottom or floor of the valve box or cup D so
as to press the ring L³ against casing cover and the box D against the face of
cylinder ports.
In Fig. 15 a cylinder A having two valves fitted, one at each end, is shown.
The cylinder has its ports E and F at each end as shown. Both-valves are.
operated by same valve spindle or stem O₁. B are the live steam inlets. The
exhaust is from the back of each valve chest K. This arrangement is suitable for
long stroke engines.
Figs. 16 and 17 show an arrangement with a plate W inserted between two
valves to meet the requirements of inside cylinder locomotives or other engines
requiring the same or similar arrangement. The plate W is inserted in the steam
chest K. The valves, which are of substantially the same structure as those
hereinbefore described, are only partially balanced by the steam, the bearing
strips L being unbalanced. The pistons may be hollowed out as shown. The
steam, as shown by the arrow to the left hand of fig., exhausts into the steam
chest K. ig.-17-is-a-view-of-the valve box D with piston removed, looking up
toward the ports of the cylinder A'.
Figs. 18, 19 and 20 show an arrangement of two balanced pistons P with valve
spindle or stem, O', between them. The steam ports are shown as split or as two
sets passing round outside of cylinder shell A. The valve box D is made in one
piece, with recesses for the-reception of the pistons P. The hoop O, passes right
round both pistons and box D as shown at Fig. 19. The valves are shown in this
case as working against a plate W in steam chest K. Of course it will be readily
-understood-that-said-double..balanced pistons are applicable whether the ports are
split or not. As shown in the plan view of the boxes D, Fig. 19, the openings H
-cut-out at bottom of boxes, may be octagon shaped instead of circular, square or
-oblong as in prior views.
===
Figs. 21 and 23 show a valve slightly different in construction from the previous
figures. Dis the valve cup or box and P the piston as before, but beside the
bearing strips L surrounding the cavity L' there are additional bearing strips g
fitted at right angles to the line of travel of the valve. Small grooves or
equivalent may be cut in the strips so as to allow the steam to pass to all parts
of the cavity L There may also be bearing strips at the ends of piston face as
shown. The valve cup D has, or may-have, a bearing strip strengthened by a
cross tilt-bar in line of travel of the valve. In some cases, if so desired, the
valve may have two or more strips h. The inlet port, B, may be tapered outwards,
as shown, to compensate for the space taken up by bearing strip h. By having the
additional bearing strips as shown all the bearing surface will be rubbed over
equally should the valve only travel a fixed part of its distance, which is an important
item with engines that are required to run a long time with travel of valve lessened.
It will be observed from Fig. 23 that the end bearing strips g' are not joined to the
cavity or balance bearing strips L.
Fig. 22 shows a valve similar to those already described with the addition of
loose bearing strips L (or ring or rings if valve is circular) fitted into recesses Pin
a thickened rim X, on top of piston P. The recesses may or may not having
packing P, in them under the strips. With loose strips or ring or rings as
aforesaid they can be easily taken out and renewed when necessary without
necessitating a total renewal of piston.
Figs. 24 and 25 show a double ported slide valve with cut off valve C. The
valve box or cup D is, in this case, shown with ports E', F', in it and an inlet
port B₁ also with exhaust ports E², F2. The pistons P work in upper part of
box D and against a bridge r. s are cavity spaces for lightening metal. The
springs J, Jare shown in this view as bearing up against lower side of piston just
below balance holes M. The valve is made as shown to economise steam space

page_text: when a cut off valve is used.
One large piston equal in area to the two small
pistons P can be used if so desired. If desired springs might with this arrangement
be fitted between upper side of back of box D and casing cover K¹.
The form of rotating or partially rotating valve shown at Figs. 26, 27 and 28 is
constructed in substantially the same manner as the other valves, hereinbefore
..described. It consists of a valve box or cup D, into which is fitted the piston P.
J, Jare springs. M balance hole. As shown in Fig. 28 the valve is circular in
plan with the valve stem O' connected to the hoop O. The part D has an oblong
port H cut in its underside. The valve is or may be rotated or partially rotated
by a rocking arm or other suitable means. The exhaust from the valve chest K is
at Z. As will be seen (Fig. 28) the inner end of the valve stem works in a recess
in the solid end K2 of valve chest K whilst the other end passes out through an
opening or the usual gland in the valve chest cover K'.
The piston, as shown at Fig. 27, is similar to those already described except that
it is curved at top as shown at Fig. 26. The rim L is, in this view, shown sectioned
for clearness although it should not in reality be so. A cut off valve C may be
used with the valve if so desired. Instead of the steam exhausting from the side of
the chest K, it may exhaust out at the back, in this case there would be fitted on
the back a loose cover with branch and a bridge across cover to receive end of
spindle or stem of valve, O', the steam escaping out over and under said bridge.
A valve, as herein before described, having a piston or cylinder (or pistons or
cylinders or equivalent) within the valve box or cup D will travel steam tight
against the face or ports of the engine cylinder and also against casing cover, or
plate inserted in the casing, and, as a portion of the steam or other fluid is locked
in the cavity L' at the top of the piston or cylinder, which cavity is equal or nearly
equal in arca to the piston or cylinder, a complete or nearly complète balance is
obtained by the inlet steam or other fluid acting on said piston or cylinder or
equivalent on both sides at one and the same time. The bearing strips or ring or
rings L, locking in the steam or other fluid in the cavity L' prevents any escape
from the side of the piston or cylinder next usual casing cover, or plate inserted in
the casing, and, should an escape occur from any cause it is limited by the balance
hole M. or its equivalent, while, at the same time, the escape would cause such a
disturbance of the balance that (the steam or other fluid acting between box D and.
piston P) the bearing strips, slips, or ring or rings I would be pressed against the
casing cover or plate with the difference of pressure caused by such escape and the
escape would thus be lessened or stopped.
With my improved balanced valve the following advantages result-
1st. That in no case can there be more pressure put upon the cylinder face or
ports with the inlet steam, air gas or other Huid than the area of part not cut out
from face of valve box or cup will allow.
2nd. That with engines exhausting into the atmosphere no packing need be used,
as, in this invention, the engine exhausts into what is usually known as the steam or
inlet chest.
3rd. That no pressure, more than that which is exerted by the escaping steam
can affect the usual steam chest joint or steam chest cover or packing, unless the
pressure of such escaping steam fall below the pressure of the atmosphere.
4th. That the steam or other ports are brought nearer to the ends of the cylinder
to an extent, equal or nearly equal to the lap or cover of valve.
5th. That a cut off valve can be used to great advantage covering inlet port
leading into valve either from what is usually known as the steam chest cover
side or from the central port on cylinder or steam chest leading into valve cup
or box.
6th. That the cut off valve may with equal facility be used as a throttle valve.
7th. That the valve box or cup D can be made with trick ports if desired.
The valve is equally applicable for any class of engine or motor where suitable
besides those driven by steam..
It is to be understood that although I have shown various modifications of my

page_text: invention I do not confine myself thereto as these are given merely as illustrations.
the valve being, manifestly, capable of being further altered without departing
from the invention.
Dated this 9th day of December 1800
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
COMEIN DE BOLNICATION.
Improvements in and connected with Equilibrated Valves for Steam
and other Engines.
I, JAMES FREW of 5 Greenhill, Dunaskin, Ayrshire Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly lescribed and ascertained in and by the following
statement:-
My invention is a development or improvement upon that class of equilibrated
valve for steam and other engines or motors wherein-the-live steam, air, gas or
other fluid is admitted into the cavity, which, in ordinary slide valves, constitutes
the exhaust port (the usual exhaust port thus constituting the steam or other fluid
inlet, and the usual inlet port constituting the exhaust) although it is to be under-
stood that the inlet steam may be admitted to the cavity of the valve in any of the
usual methods if so desired.
I will now proceed to describe my invention as applied, under various
- modifications to steam engine valves, reference being had to the drawings
accompanying my Provisional Specification whereon:-
Fig. 1 shows in section a equilibrated slide valve, with valve chest and cylinder
_ports.
--
Fig. 2 is a plan view of valve as at-Fig. with the-valve-piston removed.
Fig. 3 is a plan of the piston of the valve removed from Fig. 2.
Fig. 4 shows in section a modified form of valve with adjacent parts broken
away.
Fig. 5 is a plan of the piston of the valve Fig. 4.
Fig. 6 is a plan of the valve Fig. 4 with the piston removed.
Fig. 7 is a section of a valve piston.
Fig. 8 is a plan of the valve piston Fig. 7.
Figs. 9. 10. and 11. are sections of different constructions of valve.
Fig. 12 is a sectional plan on the line A-B Fig. 10.
Figs. 13 and 14 are sections of valves.
Fig. 15 shows in section, a cylinder with two valves fitted thereon one at
each end.
Fig. 16 shows in section a double valve arrangement for an engine with two
cylinders A, A' side by side.
Fig. 17 is a view of the upper valve box D, Fig. 16, looking towards the ports
of the cylinder A¹.
Fig. 18 shows, in section, part of a cylinder with valve and ports and passages.
Fig. 19 is a plan of the valve Fig. 18 with-piston removed.
Fig. 20 is a cross section of the valve on the line E. F, Fig. 19.
Figs. 21 and 22 are sections of valves.
Fig. 23 is a plan of the valve Fig. 21.
Fig. 24 shows in section, a double piston valve with ports and passages.
Fig. 25 is a plan of Fig. 24 with cover K' removed.
Fig. 26 shows in section a partially rotating balanced valve with accessory parts.
Fig. 27 is a plan of the piston of valve Fig. 26.
Fig. 28 is a sectional plan of valve and ports on the line G. H. Fig. 26 with
piston of valve removed.

page_text: On the drawings the same reference letters wherever repeated indicate similar or
like parts.
Referring to Figs. 1. 2, and 3, A. is the cylinder B the steam inlet port which is
fitted with a cut off valve C of the "Corliss type." D is the sliding box or cup of
the valve for the admission and release of steam to the cylinder A through the
cylinder ports E and F. The dotted lines at G G indicate the position of valve
box D when steam is being admitted to the cylinder through the port E and being
exhausted from the back of piston through the port F. As will be seen more
particularly at Fig. 2 the valve box D is made of a hollow cup shape with the
oblong induction port H cut in the face, the back part of valve box D being
completely cut away. If the valve piston P was removed as at Fig. 2 the steam
filling up the interior of the valve box D would only press down on the portions..
not cut out marked on the plan, Fig. 2. The piston P which is fitted into the
interior of the valve box or cup D has two or other number of spring rings I,
shown to a larger scale at Fig. 4 which hold themselves steam tight against the
interior face of the wall D' of the valve. box D. J, J, are spiral springs which
are fitted in recesses J2 in the piston P. Instead of using spiral springs however
any other suitable form of spring may be employed and if desired three or other
number of springs may be fitted in the valve. The object of using the springs J, J,
is to press the piston P, and, at the same time, the valve box D each against their
respective working faces in the steam chest K with sufficient force to overcome the
friction caused by the piston P, and spring rings I bearing against the inner face or
wall D of the valve box D. The steam of its own pressure has the tendency to
separate the piston P and valve box D from one another and so cause the valve to
work tight against its bearings. The piston P which may be flanged over at P¹ P²
(Figs. 1 and 3) has on its upper side, or back, bearing strips L which may be
arranged in rectangular form as shown at Fig. 3. These strips which bear steam
tight against the casing cover K¹ as shown enclose a cavity or space L. Steam
passes from the induction port H cut out of the valve box D, through a balance
hole or opening M in the piston P, to the cavity or steam space L' at the top of said
piston. The balance hole M may be either tapered, as-shown, or may be tapered
the reverse way or be a straight channel without taper right through; or there
may be two or more small channels or equivalent made in the piston in lieu of the
balance hole M. By locking steam in the cavity or space L' which is of an area
equal to the area of the cylindrical part enclosed by the wall D' of the valve D, a
true balance is maintained by the exposure of two equal areas or sides to the
opposing action of the steam. Consequently the only upward or outward pressure
on the piston P, is that due to the action of the springs J, J', so long as the bearing
strips L keep steam tight against the casing cover K'. The small opening at the
bottom of the balance hole M only admits of a small quantity of steam passing
through to the cavity or space L', and, therefore should the strips L wear down and
leak, very little steam would be lost. The top of the balance hole M may be cup
shaped or hollowed out as shown at M¹. N is a groove running round valve
piston P which serves as a trap space for any steam that might leak past the lower
ring I. On the plan view of the piston P (Fig. 3) four relief holes N¹, com-
municating between the groove trap N and the cavity or space L' are shown.
These holes N¹ carry off any leakage of steam which may pass into the trap N and
thus replaces any leakage from the cavity or space L'over the bearing strips L
should this occur.
The holes N may or may not be used as desired. O is th
usual hoop or ring passing round the valve. O' is the valve spindle or stem.
O the usual collar bush. O³ trap space. The bearing bush 04 or usual packing
gland is or may be as shown screwed hard up against collar 02. 05 is a small hole"
leading from trap space O³ into the smoke box (by means of a pipe, not shown);
or into the trap, drain, or the atmosphere. The hole 05 relieves the bearing
bush from any back pressure of steam greater than the pressure of the
atmosphere. Instead of having the bush O screwed up against collar 02 a
bearing bush driven into chest I may be used as shown in the small view to left of
.

page_text: Fig. 1 M², Fig. 2 is the steam inlet branch and M³ the exhaust outlet. is the
spindle for operating the cut off valve C.
Figs. 4, 5 and 6 show an oblong piston P as fitted into the valve cup or box D.
The valve in this case is very similar in construction to that at Figs. 1, 2, and 3
the only difference being that the valve cup D is recessed out at right angles so
that the sectional view of the side walls D¹ and face v of cup or box show like
-two-s. The cut-out-part H-of-the-face of the valve is-rectangular-as-shown in-
plan at Fig. 6. The piston P is, in this instance, made with the bearing strips L
raised all round the edge of the piston as shown at Fig. 5. The slips, 1, are in
this case, pressed against the inner face of the walls D¹ of the valve box D by
means of plate springs R'. The springs J, J, are, in this case, dispensed with,
the upward pressure of the steam being sufficient to keep strips L close against
the cover K. The holes N are in this view shown in full lines.
Figs. 7 and 8 show a piston P of cylindrical form, the only difference in its
construction from the hereinbefore described pistons being that it has no escape or
leakage holes N and that the bearing face is made in the form of a circular raised
flange rim L on the top of the piston. The slips, I, in the piston, may also be, as
shown, dispensed with the slips being inserted instead in grooves in the valve
-box D. It is shown with cavities J2 for springs the same as in Fig. 1.
Fig. 9 shows a valve with a piston P made with a recess P¹ around its upper side
into which are fitted loose bearing strips L enclosing the balancing steam space or
cavity L'. P2 is packing at the underside of the strips L. The bearing slips I
are pressed against the inner face of the wall D' the box or cup D by the
springs R which may be plate springs, as shown, or he spiral springs. The upper
slips 1, are, by spiral or other springs R³, pressed tight against the inner face of
the bearing strips L. It will be seen that the strips L press in this instance both
against the inner face of the wall D of the box or cup D and against steain thest
cover K. Plate springs J, J¹ are shown as being used in lieu of spiral springs as
at Eig. The slips-I-may or may not be used as desired:
Figs 10-and-12 show a modified construction of valve. In this case the piston-P
which is circular and very thin is fitted on top of a solid part D³ which is hollowed
out at D4 so as to form a trick port as shown. The channels N may, in this case,
as indicated in dotted lines, communicate with the-trick-port -D. Passages-De-for
steam are made through the valve. The passages, which communicate with the
"steam space D and the space D7, are or may be of rectangular formation as shown.
The steam in the spaces D and L balance the piston P. This view is merely
shown to illustrate a method of making my improved valve with a trick port. The
spindle--may-be-made in this case to pass through the valve.
Fig. 11 shows a somewhat similar valve to Figs. 10 and 12 the only difference
being that the part D³ is made solid throughout with a steam passage Ď³ in centre
instead of having a trick port D and passages D' as at Figs. 10 and 12.
Fig. 13 shows a valve somewhat similar to that at Fig. 9 with the piston P made
with a recess around its upper part. Into this recess a ring L is fitted so as to bear
against the casing cover K. The piston in this view has the balance hole M made
with the taper towards the top instead of the bottom as in the preceding figures.
With this arrangement the ring L can be renewed at any time without total
renewal of the piston or valve box D.
Fig. 14 differs-from the-foregoing-in-having the valve box or cup -D fitted-with-
a split ring L' around it, into which is or may be fitted a ring, or it may be rings, R
which bear steam tight against the walls of the box or cup D. The piston P is
also in this view shown tapered like a cone and as being fitted into the inside of
ring L. The top edge of the piston, where it is fitted just a moving fit into the
inside of ring L is shown at b. The lower flanged or bent over edge of the piston
bears, as shown against the lower edge of the ring L. This arrangement shows
the piston as without rings in itself but with a balance hole M and cavities for
springs J. J. The valve, in this case, although having a limited measure of escape
is only partially balanced (d showing the unbalanced area around top of ring).

page_text: The ring L is tapered off as much as possible consistent with leaving a sufficient
working surface as shown to reduce the unbalanced area and if it is desired to
produce a complete balance the ring L may be flanged outwards in the same
manner as the piston P Fig. 7 so that the cavity L' will be equal in area to the
interior area of the cup D. Instead of having a balance hole M through the
piston passages or openings may be made around or in the periphery of the valve so
as to allow steam to pass into the cavity L' between the periphery of the valve and
the ring LA.
In Fig. 15 a cylinder A having two valves fitted one at each end is shown. The.
cylinder has its ports E and F at each end as shown. Both valves are operated by
same valve spindle or stem O'. B are the live steam inlets. The exhaust is from the
back of each valve chest K. This arrangement is suitable for long stroke engines.
Figs. 16 and 17 show an arrangement with a plate W inserted between two
valves to meet the requirements of inside cylinder locomotives or other engines
requiring the same or similar arrangement. The plate W is inserted in the steam
chest K. The valves, which are of substantially the same structure as those,
hereinbefore described are only partially balanced by the steam, the, bearing
strips being unbalanced. The pistons P may be hollowed out as shown. The
steam, as shown by the arrow to the left hand of fig. exhausts into the steam
chest K.
•
Fig. 17 is a view of the valve box D with piston removed looking up toward the
ports of the cylinder A.
Figs. 18, 19 and 20 show an arrangement of two balanced pistons P. with valve
spindle or stem, O', between them. The steam ports are shown as split or as two,
sets passing round outside of cylinder shell A. The valve box D is made in one
piece with recesses for the reception of the pistons P. The hoop O, passes right
round both pistons and box D as shown at Fig. 19. 'The valves are shown in this,
case as working against a plate W in steam chest K. Of course it will be readily
understood that said double balanced pistons are applicable whether the ports are
split or not. As shown in the plan view of the boxes D, Fig. 19, the openings H,
cut out at bottom of the boxes may be octagon shaped instead of circular, square,"
or oblong as in prior views.
Figs. 21. and 23 show a valve slightly different in construction from the previous
figures. D is the valve cup or box and P the piston as before but beside the
bearing strips L surrounding the cavity, L' there are additional bearing strips.g
fitted at right angles to the line of travel of the valve. Small grooves or
equivalent q, may be cut in the strips g so as to allow the steam to pass to all parts
of the cavity L. There may also be bearing strips g' at the ends of piston
face as shown. The valve cup D, has or may have, a bearing strip strengthened
by a cross tilt-bar in line of travel of the valve.
In some cases, if so desired, the valve may have two or more strips h. The inlet
port, B, may be tapered outwards, as shown, to compensate for the space taken up
by bearing strip h. By having the additional bearing strips as shown 'all the
bearing surface will be rubbed over equally should the valve only travel a fixed
part of its distance, which an important item with engines that are required to
run a long time with travel of valve lessened. It will be observed from Fig. 23
that the end bearing strips g' are not joined to the cavity or balance bearing
strips L.
Fig. 22 shows a valve similar to those already described with, the addition of
loose bearing strips L (or ring or rings if valve is circular) fitted into recesses P
in a thickened rim X, on top of piston P. The recesses P¹ may or may not have
packing P in them under the strips. With loose strips or ring or rings as aforesaid
they can be easily taken out and renewed when necessary without necessitating a
total renewal of piston.
PT...
Figs. 24 and 25 show a double ported slide valve (or it may have triple or other
number of ports) with, cut off valve C. The valve box or cup D is, in this case,
shown with ports E¹, F¹'in it and an inlet port B' also with exhaust ports EF.
1,
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page_text: The pistons P work in upper part of box D and against a bridge r. s are cavity
spaces for lightening metal. The springs J. J', are shown in this view as bearing
up against lower side of piston just below balance holes M. The valve is made as
shown to economize steam space when a cut off valve is used. One large piston
equal in area to the two small pistons P can be used if so desired. If desired
springs might with this arrangement be fitted between upper side of back of box D,
and casing cover K.
The form of partially rotating valve shown at Figs. 26, 27 and 28 is constructed
in substantially the same manner as the other valves, herein before described. It
consists of a valve box or cup D, into which is fitted the piston P. J, Jare
springs. M balance hole. As shown in Fig. 28 the valve is circular in plan with
the valve stem O', connected to the hoop O. The part D has an oblong port H
cut in its underside. The valve is or may be partially rotated by a rocking arm or
other suitable means. The exhaust from the valve chest K is at Z. As will be
seen (Fig. 28) the inner end of the valve stem works in a recess in the solid end K'
of valve chest K whilst the other end passes out through an opening or the usual
gland in the valve chest cover K'.
The piston, as shown at Fig. 27 is similar to those already described except that
it is curved at top as shown at Fig. 26. . The rim L is, in this view, shown sectioned
for clearness although it should not in reality be so shown. A cut off valve C may
be used with the valve if so desired. Instead of the steam exhausting from the side
of the chest Kit may exhaust out at the back, in this case there would be fitted on
the back a loose cover with branch and a bridge across cover to receive end of
spindle or stem of valve, O', the steam escaping out over and under said bridge.
Instead of using two springs such as J, Ja single large spring, either spiral or 2
volute, may be used. This spring may bear against the under-side-of the-piston
and surround a collar guard fitted in the inside of the cup, D or the spring may be.
fitted in a recess-in-the-piston. If used the collar guard would be for the purpose
of preventing parts of the spring -if-broken,-getting-through.the opening H and so.
to the valve face.
Instead of allowing the steam to pass through the balance hole M, to the cavity L'
to produce a balance, it may be conducted, by a small pipe, from the inlet port B
outside of the valve box K and down through the cover so as to supply steam to
the cavity.
A valve, as hereinbefore described, having a piston or cylinder (or pistons or
cylinders or equivalent) within the valve box or cup D will travel steam tight
against the face or parts of the engine cylinder and also against casing cover, or
plate, inserted in the casing, and as a portion of the steam or other fluid is locked
in the cavity at the top of the piston or cylinder, which cavity is equal or nearly
equal in area to the piston or cylinder, a complete or nearly complete balance is 4
obtained as the inlet steam or other fluid acts on said piston or cylinder or
equivalent on both sides at one and the same time. The bearing strips or ring or
rings L locking in the steam or other fluid in the cavity I prevents any escape
from the side of the piston or cylinder next usual casing cover or plate inserted in
the casing and should an escape occur from any cause it is limited by the balance 4
hole M or its equivalent, while, at the same time, the escape would cause such a
-disturbance of the balance that (the steam or other fluid acting between box D and
piston P), the bearing strips, slips, or ring or rings L would be pressed against the
casing cover or plate with the difference of pressure caused by such escape and the
escape would thus be lessened or stopped.
With my improved balanced valve the following advantages result:-
-
1st. That in no case can there be more pressure put upon the cylinder face or
ports, with the inlet steam, air gas or other fluid than the area of part not cut out
from face of valve box or cup will allow.
5
2nd. That with engines exhausting into the atmosphere no packing need be 5
used on the valve stem, as in this invention, the engine exhausts into what is usually
known as the steam or inlet chest.

page_text: 3rd. That no pressure, more than that which is exerted by the escaping steam
can affect the usual steam chest joint or steam chest cover or packing unless the
pressure of such escaping steam fall below the pressure of the atmosphere.
4th. That the steam or other ports are brought nearer to the ends of the cylinder
to an extent, equal or nearly equal to the lap or cover of valve.
5th. That a cut off valve can be used to great advantage covering inlet port
leading into the valve from the central port on cylinder leading into valve cup
or box.
6th. That the cut off valve may with equal facility be used as a throttle valve.
7th. That the valve box or cup D can be made with trick ports if desired.
The valve is equally applicable for any class of engine or motor where suitable
besides those driven by steam.
It is to be understood that although I have shown various modifications of my
invention I do not confine myself thereto as these are given merely as illustrations,
the valve being manifestly capable of being further altered without departing from
the invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. An equilibrated valve for steam or other engines wherein the live steam or
other fluid which is admitted through the usual exhaust port, is caused to bear on
both sides of a piston or cylinder (or pistons or cylinders or equivalent), carried or
working in the valve at one and the same time and thus effect a complete or nearly
complete balance, substantially as hereinbefore set forth.
2. An equilibrated valve for steam or other engines consisting of a box or cup
having a piston fitted in it, said piston having a balance hole or opening through it
and a balancing cavity or space at its upper side, the live steam or other fluid which
is admitted to the underside of the valve bearing on both sides of the piston at one
and the same time, substantially as set forth.
3. The combination with the valve-chest, of a box or cup having an induction
opening therein, a piston or cylinder carried by or working in said box or cup and
provided with an opening through it, and bearing strips affixed to or made one with
the upper side of said piston and enclosing a cavity or space at the back or upper
side of said piston, substantially as and for the purpose set forth.
4. In equilibrated valves the combination with a cut out valve-box or cup, having
an induction opening therein, of a piston or cylinder working or fitted in said box
or cup and provided with an opening through it and with a balancing cavity at its
back or upper side, and a spring or springs, co-operating with said box or cup and
piston to press the same to their respective working surfaces, substantially as set
forth.
5. In equilibrated valves, the combination with a cut out box or cup having an
induction opening therein and a piston or cylinder fitted in said box or cup and
provided with an opening through it and a balancing cavity in its upper side, of
springs (as J, J) and bearing strips or rings fitted to the upper side of said piston,
substantially as set forth.
6. The combination with the cut out cup or box D, having an induction opening
therein of a piston or cylinder carried by said cup or box and provided with an
opening through it and with a cavity as L' in its back, and also with a trap space
or groove, as N; and relief holes, as N¹ communicating with the trap space N and
cavity L, and spring rings as I, substantially as set forth.
7. The equilibrated valve substantially as hereinbefore described with reference
to Figs. 1, 2 and 3 of the drawings annexed to the Provisional Specification.
8. The several modified constructions of equilibrated valve substantially as
hereinbefore described with reference to Figs 4 to 28 of the drawings annexed to
the Provisional Specification.
9. The combination with a balanced valve of the construction hereinbefore set
.

page_text: forth of a cut off or throttle valve C fitted in the inlet port substantially as herein-
before set forth with reference to the drawings annexed to the Provisional
Specification.
Dated this 21st day of September 1891.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent: