IMPROVEMENTS IN SLIDE
Year: 1885

page_text: The decision of the Comptroller-General, of the 18th day of October 1894,
allowed, under Section 18 of the Patents, &c. Act, 1883, an Amendment
of this Specification.
I, J JOHN EATOCK, of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for
VALVES to be as follows:-
"IMPROVEMENTS IN SLIDE
This invention relates to an improved slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the
object being to provide a valve upon which the pressure of the steam shall not act
to press it against or hold it to its seat and thus to prevent the additional friction
consequent thereon.
I form the steam and exhaust ports of the cylinder in the usual manner, each
leading to an opening in a planed plate the three forming a grating. For upright
or horizontal cylinders where the valve chest is placed on top, I form in the plate
in the bottom of the valve chest a grating corresponding to that described and bolt.
the one exactly over the other. These lead into a chamber in each side of the valve
chest, each of which is fitted with corresponding divisions or ports so that the ports
For horizontal
of the cylinder lead up to and enter the valve chest at each side.
cylinders where the chest is placed at the side, I prefer to bolt it onto the side of
the cylinder with a single plate corresponding to the plate on the cylinder, the ports
opening directly through into the interior. On the opposite side of the chest the
plate which forms the back bearing for the slide planed, but without openings or
perforations.
In each case the valve bears against two seats.
These seats converge slightly
towards each other at the bottom, though longitudinally they are parallel the one
to the other. The valve is made with two faces, one of which bears against each
seat in the valve chest and is made slightly tapering towards the bottom to corre-
spond with the convergence in the seats. The faces of the valve are preferably
rectangular, and as it is made open or hollow through the centre, each face presents
the appearance of a hollow square or rectangle. Strengthening or connecting
pieces may be inserted in the hollow. The area of the faces of the valve. will of
course be proportionate to the size of the ports, and the spaces which will be placed
between them, and the hollow of sufficient area to connect the steam ports alter-
nately with the exhaust port. A chipping piece is cast on the bottom of the valve
which bears on the bottom of the chest. The valve in the first instance having
been planed to exactly fit the valve chest and fit between its two seats with the
chipping piece at the same time resting on the bottom, it will require but little
further attention to keep it tight and in order, as any wear will be compensated
for by the taper valvė gradually falling deeper between the converging sides, while

page_text: at the same time the bottom chipping piece will counteract any tendency to become
fast or stick. A slight spring may be placed on top to prevent the valve rising
from its proper position. Space is left for the free access of the steam above, below,
and at each end of the valve. The steam may be admitted into the valve chest at
any convenient position, and enters the cylinder through the ports alternately as
the valve moves to and fro. The valve having two faces and working against two
seats prevents any pressure of the steam getting at either side to hold it to its seat,
and the steam having free access above, below and to each end of the valve it is
practically in equilibrio. The valve is actuated in the usual way by a rod from an
eccentric passing through a stuffing box in the side of the valve chest.
Dated this 10th day of February 1885.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.
I, JOHN EATOCK of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for IMPROVEMENTS IN SLIDE
VALVES 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 slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the object
being to provide a valve upon which the pressure of the steam shall not act to press
it against or hold it to its seat, and thus to prevent the additional friction con-
sequent thereon, and which can easily be adjusted to wear.
The invention is best described by aid of the accompanying drawings of a
specimen cylinder and valve in which
Figure 1 shows a section in line with the face of the valve and,
Figure 2 section through the steam port, and at right angles to Figure 1.
In these A is the cylinder. B B steam ports, exhaust port connected with
the condenser or chimney in any convenient manner. D valve made slightly
wedge shaped, and fitting with planed surfaces against two preferably similarly
inclined seats E F, one on each side. The valve D has a chipping piece Gat
bottom, resting on a planed surface. This wears with the valve, and thus the valve
gradually lowers as it wears. If necessary, from time to time the valve can be taken
out, and a thin strip cut from the chipping strip so as to bed the valve well onto its
two seats. It will require but little further attention to keep this valve tight and
in order, as any wear will be compensated for by the taper valve gradually falling
deeper between the converging sides, while at the same time the bottom chipping
piece will counteract any tendency to become fast or stick. A slight spring may
be placed on top to prevent the valve rising from its proper position, or check
screw H can be used instead. Space is left for the free access of the steam above
below and at each end of the valve. The steam may be admitted into the valve
chest at any convenient position, as at T. It enters the cylinder through the two
steam ports alternately as the valve moves to and fro. The valve having two faces
and working against two seats prevents any pressure of the steam getting at either
side to hold it to its seat, and the steam having free access above, below, and to
each end of the valve it is practically in equilibrio. The valve is actuated in the
usual way by a rod from an eccentric passing through a stuffing box in the side of
the valve chest. The valve should be at least as thick as the width of the exhaust
port.
It will be obvious that the valve seats and passages can be varied considerably.

page_text: thus the cylinder might be benenth-the-valve,-and-equal-and-similar-ports-and
passages on both sides lead down to it.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I wish it to be
understood that balanced slide valves with two faces in which the steam passes alternately
through the valve to the cylinder and from the cylinder through the valve to the exhaust,
the ports being parallel and with the valve box above the horizontal cylinder, have been
proposed before the date of my Patent, but either it has been proposed to support the
valves solely by the valve-rod, in which case the calves would have to be made parallel
and consequently there would be no allowance for wear, and so they would quickly become
leaky, and indeed it would be almost impossible to make them a tight fit even at the start,
much more after a little working, or else the valves were loose on their valve-rods and
supported on their broad bottoms, and from the nature of the valves their bottoms had to
be broad. In this latter case, nearly all the good of the two balanced faces was lost, as
the unbalanced pressure on the top surface, pressing the broad bottom against its
seat, made matters worse, and I believe therefore these proposals were abandoned as
impracticable and never carried out in practice; also that extremely long double-balanced
valves have been proposed in which the steam passed through the valve to the cylinders
and round the end of the valve from the cylinders to the exhaust, the valve being
proposed to be supported on broad flanges, but this also I believe was never adopted in
practice, being too cumbersome and wasteful of steam in the numerous large steam
passages, but my invention differs from these in that my valve device is a practical one,
that the pressure on the valve surface is entirely balanced except for the narrow chipping
strip, that the valve is in great measure self-adjusting for wear and tear and is applied
on the side of the cylinder instead of, as in the cases alluded to, abore it, and i make no
claim for either of the aforesaid proposed plans, all of which I believe to be quite useless
in practice, but I declare that what I claim is
1st. A valve apparatus for steam engines in which a single perforated block
having two similar faces, acts as a slide valve working against two similar valve
seats, having steam and exhaust ports one on each side, substantially as described,
and subject to the disclaiming clause.
2nd. In combination with a double faced slide valve having a port piereed
right through it from face to face two valve seats each having ordinary steam
ports, leading to the cylinder ends and exhaust port between, substantially-as
described.
3rd. 2nd. The combination of a wedge shaped slide valve, sliding on two
inclined faces and having a chipping piece at bottom by which means wear can be
taken up to any required extent.
WM P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.
September
WP. THOMPSON & Co., .
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.

page_text: I, JOHN EATOCK, of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for "IMPROVEMENTS IN SLIDE
VALVES" to be as follows:-
This invention relates to an improved slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the
object being to provide a valve upon which the pressure of the steam shall not act
to press it against or hold it to its seat and thus to prevent the additional friction
consequent thereon.
I form the steam and exhaust ports of the cylinder in the usual manner, each
leading to an opening in a planed plate the three forming a grating. For upright
or horizontal cylinders where the valve chest is placed on top, I form in the plate
in the bottom of the valve chest a grating corresponding to that described and bolt
the one exactly over the other. These lead into a chamber in each side of the valve
chest, each of which is fitted with corresponding divisions or ports so that the ports
of the cylinder lead up to and enter the valve chest at each side. For horizontal
cylinders where the chest is placed at the side, I prefer to bolt it onto the side of
the cylinder with a single plate corresponding to the plate on the cylinder, the ports
opening directly through into the interior. On the opposite side of the chest the
plate which forms the back bearing for the slide is planed, but without openings or
perforations.
In each case the valve bears against two seats. These seats converge slightly
towards each other at the bottom, though longitudinally they are parallel the one
to the other. The valve is made with two faces, one of which bears against each
seat in the valve chest and is made slightly tapering towards the bottom to corre-
spond with the convergence in the seats. The faces of the valve are preferably
rectangular, and as it is made open or hollow through the centre, each face presents
the appearance of a hollow square or rectangle. Strengthening or connecting
pieces may be inserted in the hollow. The area of the faces of the valve will of
course be proportionate to the size of the ports, and the spaces which will be placed
between them, and the hollow of sufficient area to connect the steam ports alter-
nately with the exhaust port. A chipping piece is cast on the bottom of the valve
which bears on the bottom of the chest. The valve in the first instance having
been planed to exactly fit the valve chest and fit between its two seats with the
Pains 71

page_text: chipping piece at the same time resting on the bottom, it will require but little
further attention to keep it tight and in order, as any wear will be compensated
for by the taper valve gradually falling deeper between the converging sides, while
at the same time the bottom chipping piece will counteract any tendency to become
fast or stick. A slight spring may be placed on top to prevent the valve rising
from its proper position. Space is left for the free access of the steam above, below,
and at each end of the valve. The steam may be admitted into the valve chest at
any convenient position, and enters the cylinder through the ports alternately as
the valve moves to and fro. The valve having two faces and working against two
seats prevents any pressure of the steam getting at either side to hold it to its sent,
and the steam having free access above, below and to each end of the valve it is
practically in equilibrio. The valve is actuated in the usual way by a rod from an
eccentric passing through a stuffing box in the side of the valve chest.
WM P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.

page_text: I, JOHN EATOCK of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for IMPROVEMENTS IN SLIDE
VALVES 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 slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the object
being to provide a valve upon which the pressure of the steam shall not act to press
it against or hold it to its sent, and thus to prevent the additional friction con-
sequent thereon, and which can easily be adjusted to wear.
The invention is best described by aid of the accompanying drawings of a
specimen cylinder and valve in which
Figure 1 shows a section in line with the face of the valve and,
Figure 2 section through the steam port, and at right angles to Figure 1.
In these A is the cylinder. B B steam ports, C exhaust port connected with
the condenser or chimney in any convenient manner. D valve made slightly
wedge shaped, and fitting with planed surfaces against two preferably similarly
inclined seats E F, one on each side. The valve D has a chipping piece G at
bottom, resting on a planed surface. This wears with the valve, and thus the valve
gradually lowers as it wears. If necessary, from time to time the valve can be taken
out, and a thin strip cut from the chipping strip so as to bed the valve well onto its
two seats. It will require but little further attention to keep this valve tight and
in order, as any wear will be compensated for by the taper valve gradually falling
deeper between the converging sides, while at the same time the bottom chipping
piece will counteract any tendency to become fast or stick. A slight spring may
be placed on top to prevent the valve rising from its proper position, or check
screw H can be used instead. Space is left for the free access of the steam above
below and at each end of the valve. The steam may be admitted into the valve
chest at any convenient position, as at I. It enters the cylinder through the two
steam ports alternately as the valve moves to and fro. The valve having two faces
and working against two seats prevents any pressure of the steam getting at either
side to hold it to its seat, and the steam having free access above, below, and to
each end of the valve it is practically in equilibrio. The valve is actuated in the
usual way by a rod from an eccentric passing through a stuffing box in the side of
the valve chest. The valve should be at least as thick as the width of the exhaust
port.
It will be obvious that the valve seats and passages can be varied considerably,
thus the cylinder might be beneath the valve, and equal and similar ports and
passages on both sides lead down to it.
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
1st. A valve apparatus for steam engines in which a single perforated block
having two similar faces, acts as a slide valve working against two similar valve
seats, one on each side, substantially as described.

page_text: 2nd. In combination with a double faced slide valve having a port pierced
right through it from face to face two valve seats each having ordinary steam
ports, leading to the cylinder ends and exhaust port, between, substantially as
described.
3rd. The combination of a wedge shaped slide valve, sliding on two inclined
faces and having a chipping piece at bottom by which means wear can be taken up
to any required extent.

page_text: The decision of the Comptroller-General, of the 18th day of October 1894,
allowed, under Section 18 of the Patents, &c. Act, 1883, an Amendment
of this Specification.
I, JOHN EATOCK, of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for "IMPROVEMENTS IN SLIDE
VALVES to be as follows:-
5
This invention relates to an improved slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the
object being to provide a valve upon which the pressure of the steam shall not act
to press it against or hold it to its seat and thus to prevent the additional friction
consequent thereon.
each
I form the steam and exhaust ports of the cylinder in the usual manner,
leading to an opening in a planed plate the three forming a grating. For upright
or horizontal cylinders where the valve chest is placed on top, 1 form in the plate
in the bottom of the valve chest a grating corresponding to that described and bolt
the one exactly over the other. These lead into a chamber in each side of the valve
chest, each of which is fitted with corresponding divisions or ports so that the ports
of the cylinder lead up to and enter the valve chest at each side. For horizontal
cylinders where the chest is placed at the side, I prefer to bolt it onto the side of
the cylinder with a single plate corresponding to the plate on the cylinder, the ports
opening directly through into the interior. On the opposite side of the chest the
plate which forms the back bearing for the slide is planed, but without openings or
perforations.
In each case the valve bears against two seats.
These seats converge slightly
towards each other at the bottom, though longitudinally they are parallel the one
to the other. The valve is made with two faces, one of which bears against each
seat in the valve chest and is made slightly tapering towards the bottom to corre-
spond with the convergence in the seats. The faces of the valve are preferably
rectangular, and as it is made open or hollow through the centre, each face presents
the appearance of a hollow square or rectangle. Strengthening or connecting
pieces may be inserted in the hollow. The area of the faces of the valve will of
course he proportionate to the size of the ports, and the spaces which will be placed
between them, and the hollow of sufficient area to connect the steam ports alter-
nately with the exhaust port. A chipping piece is cast on the bottom of the valve
which bears on the bottom of the chest. The valve in the first instance having
been planed to exactly fit the valve chest and fit between its two seats with the
chipping piece at the same time resting on the bottom, it will require but little
further attention to keep it tight and in order, as any wear will be compensatel
for by the taper valve gradually falling deeper between the converging sides, while

page_text: at the same time the bottom chipping piece will counteract any tendency to become
fast or stick. A slight spring may be placed on top to prevent the valve rising
from its proper position. Space is left for the free access of the steam above, below,
and at each end of the valve. The steam may be admitted into the valve chest at
any convenient position; and enters the cylinder through the ports alternately as
the valve moves to and fro. The valve having two faces and working against two
seats prevents any pressure of the steam getting at either side to hold it to its seat,
and the steam having free access above, below and to each end of the valve it is
practically in equilibrio. The valve is actuated in the usual way by a rod from an
eccentric passing through a stuffing box in the side of the valve chest.
Dated this 10th day of February 1885.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.
Improvements in Slide Valves.
1, JOHN EATOCK of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for IMPROVEMENTS IN SLIDE
VALVES 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 slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the object
being to provide a valve upon which the pressure of the steam shall not act to press
it against or hold it to its seat, and thus to prevent the additional friction con-
sequent thereon, and which can easily be adjusted to wear.
The invention is best described by aid of the accompanying drawings of a
specimen cylinder and valve in which
Figure 1 shows a section in line with the face of the valve and,
Figure 2 section through the steam port, and at right angles to Figure 1.
In these A is the cylinder. B B steam ports, exhaust port connected with
the condenser or chimney in any convenient manner. D valve made slightly
wedge shaped, and fitting with planed surfaces against two preferably similarly
inclined seats E F, one on each side. The valve D has a chipping piece Gat
hottom, resting on a planed surface. This wears with the valve, and thus the valve
gradually lowers as it wears. If necessary, from time to time the valve can be taken
out, and a thin strip cut from the chipping strip so as to bed the valve well onto its
two seats. It will require but little further attention to keep this valve tight and
in order, as any wear will be compensated for by the taper valve gradually falling
deeper between the converging sides, while at the same time the bottom chipping
piece will counteract any tendency to become fast or stick. A slight spring may
be placed on top to prevent the valve rising from its proper position, or check
screw H can be used instead. Space is left for the free access of the steam above
below and at each end of the valve. The steam may be admitted into the valve
chest at any convenient position, as at T. It enters the cylinder through the two
steam ports alternately as the valve moves to and fro. The valve having two faces
and working against two seats prevents any pressure of the steam getting at either
side to hold it to its seat, and the steam having free access above, below, and to
each end of the valve it is practically in equilibrio. The valve is actuated in the
usual way by a rod from an eccentric passing through a stuffing box in the side of
the valve chest. The valve should be at least as thick as the width of the exhaust
port.
It will be obvious that the valve seats and passages can be varied considerably.

page_text: thus-the-cylinder-might-be-beneath-the-valve,-and--equal and similar-ports-and
passages on both sides lead down to it.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I wish it to be
understood that balanced slide valves with two faces in which the steam passes alternately
through the valve to the cylinder and from the cylinder through the valve to the exhaust,
the ports heing parallel and with the valve box above the horizontal cylinder, have been
proposed before the date of my Patents but either it has been proposed to support the
valves solely by the valve-rod, in which case the valves would have to be made parallel
and consequently there would be no allowance for wear, and so they would quickly become
leaky, and indeed it would be almost impossible to make them a tight fit even at the start,
much more after a little working, or else the valres were loose on their calve-rods and
supported on their broad bottoms, and from the nature of the valves their bottoms had to
be broad. In this latter case, nearly all the good of the two balanced faces was lost, as
the unbalanced pressure on the top surface, pressing the broad bottom against its
seat, made matters worse, and I believe therefore these proposals were abandoned as
impracticable and never carried out in practice; also that extremely long double-balanced
valves have been proposed in which the steam passed through the valve to the cylinders
and round the end of the valve from the cylinders to the exhaust, the valve being
proposed to be supported on broad flanges, but this also I believe was never adopted in
practice, being too cumbersome and wasteful of steam in the numerous large steum
passages, but my invention differs from these in that my valve device is a practical one,
that the pressure on the valve surface is entirely balanced except for the narrow chipping
strip; that the valve is in great measure self-adjusting for wear and tear and is applied
on the side of the cylinder instead of, as in the cases alluded to, abore it, and i make no
claim for either of the aforesaid proposed plans, all of which I believe to be quite useless
in practice, but I declare that what I claim is
1st. A valve apparatus for steam engines in which a single perforated block
having two similar faces, acts as a slide valve working against two similar valve
seats, having steam and exhaust ports one on each side, substantially as described,
and subject to the disclaiming clause.
2nd. In combination with a double faced slide valve having a port-pierced
right through it from face to face two valve seats each having ordinary steam
porto, leading to the cylinder ends and exhaust port between, substantially-as
described.
3rd 2nt. The combination of a wedge shaped slide valve, sliding on two
inclined faces and having a chipping piece at bottom by which means wear can be
taken up to any required extent.
W P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool; and
323, High Holborn, Londou,
Patent Agents for the Applicant.
Dated this fɔth day of September του
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool; and
323, High Holborn, Londou,
Patent Agents for the Applicant.

page_text: I, JOHN EATOCK, of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for "IMPROVEMENTS IN SLIDE
VALVES" to be as follows:-
This invention relates to an improved slide valve for actuating the ports for the
admission to and discharge of steam from the cylinder of a steam engine; the
object being to provide a valve upon which the pressure of the steam shall not act
to press it against or hold it to its seat and thus to prevent the additional friction
consequent thereon.
"I form the steam and exhaust ports of the cylinder in the usual manner, each
leading to an opening in a planed plate the three forming a grating. For upright
or horizontal cylinders where the valve chest is placed on top, I form in the plate
in the bottom of the valve chest a grating corresponding to that described and bolt
the one exactly over the other. These lead into a chamber in each side of the valve
chest, each of which is fitted with corresponding divisions or ports so that the ports
of the cylinder lead up to and enter the valve chest at each side. For horizontal
cylinders where the chest is placed at the side, I prefer to bolt it onto the side of
the cylinder with a single plate corresponding to the plate on the cylinder, the ports
opening directly through into the interior. On the opposite side of the chest the
plate which forms the back bearing for the slide is planed, but without openings or
perforations.
In each case the valve bears against two seats. These seats converge slightly
towards each other at the bottom, though longitudinally they are parallel the one
to the other. The valve is made with two faces, one of which bears against each
seat in the valve chest and is made slightly tapering towards the bottom to corre-
spond with the convergence in the seats. The faces of the valve are preferably
rectangular, and as it is made open or hollow through the centre, each face presents
the appearance of a hollow square or rectangle. Strengthening or connecting
pieces may be inserted in the hollow. The area of the faces of the valve will of
course be proportionate to the size of the ports, and the spaces which will be placed
between them, and the hollow of sufficient area to connect the steam ports alter-
nately with the exhaust port. A chipping piece is cast on the bottom of the valve
which bears on the bottom of the chest. The valve in the first instance having
been planed to exactly fit the valve chest and fit between its two seats with the
D.

page_text: chipping piece at the same time resting on the bottom, it will require but little
further attention to keep it tight and in order, as any wear will be compensated
for by the taper valve gradually falling deeper between the converging sides, while
at the same time the bottom chipping piece will counteract any tendency to become
fast or stick. A slight spring may be placed on top to prevent the valve rising
from its proper position. Space is left for the free access of the steam above, below,
and at each end of the valve. The steam may be admitted into the valve chest at
any convenient position, and enters the cylinder through the ports alternately as
the valve moves to and fro. The valve having two faces and working against two
seats prevents any pressure of the steam getting at either side to hold it to its sent,
and the steam having free access above, below and to each end of the valve it is
practically in equilibrio. The valve is actuated in the usual way by a rod from an
eccentric passing through a stuffing box in the side of the valve chest.
W P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.

page_text: I, JOHN EATOCK of Platt Bridge, Hindley, in the county of Lancaster, Engineer
do hereby declare the nature of my said invention for IMPROVEMENTS IN SLIDE
VALVES 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 slide valve for actuating the ports for tho
admission to and discharge of steam from the cylinder of a steam engine; the object
being to provide a valve upon which the pressure of the steam shall not act to press
it against or hold it to its seat, and thus to prevent the additional friction con-
sequent thereon, and which can easily be adjusted to wear.
The invention is best described by aid of the accompanying drawings of a
specimen cylinder and valve in which
Figure 1 shows a section in line with the face of the valve and,
Figure 2 section through the steam port, and at right angles to Figure 1.
In these A is the cylinder. B B steam ports, Cexhaust port connected with
the condenser or chimney in any convenient manner. D valve made slightly
wedge shaped, and fitting with planed surfaces against two preferably similarly
inclined seats E F, one on each side. The valve D has a chipping piece Gat
bottom, resting on a planed surface. This wears with the valve, and thus the valve
gradually lowers as it wears. If necessary, from time to time the valve can be taken
out, and a thin strip cut from the chipping strip so as to bed the valve well onto its
two seats. It will require but little further attention to keep this valve tight and
in order, as any wear will be compensated for by the taper valve gradually falling
deeper between the converging sides, while at the same time the bottom chipping
piece will counteract any tendency to become fast or stick. A slight spring may
be placed on top. to prevent the valve rising from its proper position, or check
screw H can be used instead. Space is left for the free access of the steam above
below and at each end of the valve. The steam may be admitted into the valve
chest at any convenient position, as at I. It enters the cylinder through the two
steam ports alternately as the valve moves to and fro. The valve having two faces
and working against two seats prevents any pressure of the steam getting at either
side to hold it to its seat, and the steam having free access above, below, and to
cach end of the valve it is practically in equilibrio. The valve is actuated in the
usual way by a rod froin an eccentric passing through a stuffing box in the side of
the valve chest. The valve should be at least as thick as the width of the exhaust
port.
It will be obvious that the valve seats and passages can be varied considerably,
thus the cylinder might be beneath the valve, and equal and similar ports and
passages on both sides lead down to it.
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
1st. A valve apparatus for steam engines in which a single perforated block
having two similar faces, acts as a slide valve working against two similar valve
seats, one on each side, substantially as described.

page_text: 2nd. In combination with a double faced slide valve having a port pierced
right through it from face to face two valve seats each having ordinary steam
ports, leading to the cylinder ends and exhaust port. between, substantially as
described.
3rd. The combination of a wedge shaped slide valve, sliding on two inclined
faces and having a chipping piece at bottom by which means wear can be taken up
to any required extent.
Dated this 15th day of September 1885.
W P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant