Improvements in or relating to Valve Mechanism especially suitable for Engines for Compressing Air and Gases.
Year: 1894

page_text: Date of Application, 28th. May, 1894
Complete Specification Left, 27th Mar., 1895-Accepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to Valve Mechanism especially suitable
for Engines for Compressing Air and Gases.
"
We, JOHN SCARISBRICK WALKER, THOMAS. ASCROFT WALKER, and EDWIN
ROBERT WALKER, Engineers, of Pagefield Iron Works, Wigan, in the County.of
Lancaster, do hereby declare the nature of this invention to be as follows:-
This invention relates to valve mechanism especially for engines for compressing
air and gases though it may be otherwise applied. We will describe it however as
applied to a compression engine for air or gases. The chief-points that we have.in
view in this invention are accessibility to the valves without the necessity for
removing the cylinder cover; this is a particularly important point where large-
sized cylinders are concerned. Another point is that we have so arranged the
parts as to be able to see the actual clearance between the piston and the valve
when the former is at the end of its stroke. This is very important since it
enables us to work with safety with a smaller amount of clearance than can be
done with the ordinary arrangements and a consequent saving is effected in the
working of the engines. Another point is the means adopted to prevent chattering
and to ensure smooth operation of the valves.
For securing the accessibility and visibility of the valves we prefer to adopt
the following arrangement. We divide the cylinder cover into two parts so that
it is only necessary to remove one part instead of the whole cover to give access
to either or any one of the valves; the two parts would be bolted together besides
being bolted on to the end of the cylinder. However in order to give accessibility
to the valves and allow these latter to be removed without the necessity for removing
the cover or even the part cover we form in the cover or in the part cover an opening
sufficiently large for the valve to pass through; this opening is closed by any
suitable cover or bonnet which may be bolted or otherwise securely fastened to it.
The valve we prefer to use is a form of hinge valve which may be carried upon its
own bearings or trunnions or may have a spindle or equivalent passing through it
or may be otherwise suitably hung. Preferably the opening is formed in the top
of the cover and the valve when upon its seat and closed hangs vertically downwards
so that its back or the portion facing the end of the cylinder lies flat in a vertical
plane, and the piston can be moved to the end of its stroke against the valve and
the space between the piston and valve can be absolutely gauged by looking
through the opening or inserting a distancerpiece or the like; a very important
point being that the engineer can look straight between the valve and the piston
and, thus .absolutely see what clearance there is. Also, if necessary. the, effect in
working can be seen by, this means.,
To prevent chattering, and generally to regulate the moving.of the valve we
prefer to connect it by a link or equivalent with a suitable slide or bearing which
may be conveniently formed as a cylinder and piston the end, of the sliding bearing
being carried to a suitable distance and there caused to pass through a friction or
brake device by which a certain' brake resistance or absence of freedom can be
imparted to the valve which is thus prevented from chattering and caused to move
smoothly throughout. its course, besides being adaptable while the engine is at
work to the varying conditions of speed and pressure and also controlled by springs
which may be arranged upon or in connection with the previously mentioned brake

page_text: device. The springs will act to a considerable extent to buffer the valve as it
approaches its seat and also to help it off its seat again when the piston moves upon
its return stroke.
The details of the braking device may be very considerably varied without
departing from the spirit of the invention, but an arrangement which gives
good results consists of a suitable bearing which may be formed of two steps,
an indiarubber or other springy or cushioning device and a screw or equivalent
for applying and regulating the pressure. If desired instead of plain bearings
one or even both may be formed by rollers or equivalent the pressure of which
upon the bar or rod connecting with the valve and the ease with which they
revolve can be varied at will and whilst the engine is at work. The bar may
be round, or if preferred it may be flattened so as to provide a certain amount
of spring or adaptability whereby it can accommodate itself to any dropping of
the valve out of alignment owing to the wearing of the parts. This arrangement
would also facilitate the original setting of the parts. Other means bowever
may be employed to secure the alignment or to prevent straining or twisting
due to the parts, working out of alignment. Any desired means may be employed
for moving the brake devices together or apart so as to increase or decrease the
pressure and braking effect and as these parts are all outside the cover they are
readily accessible when the engine is at work.
To increase or provide the buffering arrangement for the valve we prefer to have
upon the brake rod or some other suitable part a flange which is preferably in
the form, of a nut and provided also with a lock nut so that its position upon
the rod may be adjusted as required. This flange is so arranged that at the end
of the valve stroke in either direction it will come into contact with a rubber block
or buffer suitably arranged and having sufficient resiliency or compression and
expansion movement to check the valve as it approaches its seat, but nevertheless
to allow it to fully bear upon its seat, when the pressure comes upon it. By this
means the valve is prevented from banging on to its seat but is nevertheless allowed
to sit fairly upon it. This in conjunction with the braking device and the springs
controls in every respect the valve allowing it full freedom and delicacy of
movement while at the same time preventing chattering or undue movement and
enabling it either automatically to accommodate itself to variations in speed or
pressure due to the working conditions or this accommodation can be promptly
provided by the attendant adjusting the devices provided for the purpose."
Dated this 24th day of May 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicants.
Improvements in or relating to Valve Mechanism especially suitable
for Engines for Compressing Air and Gases.
We, JOHN SCARISBRICK WALKER, THOMAS ASCROFT WALKER and EDWIN
ROBERT WALKER, of Pagefield Iron Works, Wigan in the County of Lancaster,
Engineers, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates to valve mechanism especially for engines for compressing
air and gases, though it may be otherwise applied. We will describe it however as
applied to a compression engine for air or gases. The chief points that we have in
view in this invention are accessibility to the valves without the necessity for..
removing the cylinder cover; this is a particularly important point where large

page_text: sized cylinders are concerned. Another point is that we have so arranged the
parts as to be able to see the actual clearance between the piston and the valve
when the former is at the end of its stroke. This is very important since it
enables us to work with safety with a smaller amount of clearance than can be done
with the ordinary arrangements and a consequent saving is effected in the working
of the engines. Another point is the means adopted to prevent chattering and to
ensure smooth operation of the valves.
The invention will be understood from the following description reference being
had to the accompanying drawing, in which
Figure 1 is a general sectional view of a portion of the air-compressing cylinder,
the inlet and outlet valves, and the controlling apparatus;
Figures 2 to 9 inclusive detail views of the brake device;
Figure 10 part plan of the cylinder cover and the controlling apparatus for the
inlet valve;
Figure 11 plan of the controlling apparatus for the outlet valve;
Figure 12 end elevation of the cylinder cover; and
Figure 13 fragmentary vertical section through cylinder cover.
For securing the accessibility and visibility of the valves, we prefer to adopt the
following arrangement. We divide the cylinder cover in which the inlet and outlet
valves are placed into two parts, A. and B, so that it is only necessary to remove
one part instead of the whole cover to give access to either the inlet valve C or
outlet valve D. The two parts A and B form a chest for the valves C and D and
are provided with flanges a a so that they can be bolted together besides being
bolted on to the end of the compressing cylinder E. However in order to give
accessibility to the valves C and D and allow the former to be removed without
the necessity for removing the cover or even the part cover A or B, we form
in the cover or in the part cover an opening F sufficiently large for the valve
to pass through; this opening is closed by a suitable cover or bonnet F' which
may be bolted through the flanges f, or otherwise securely fastened to it. The
inlet and outlet valves we prefer to use are a form of hinge valve which may
be carried upon their own bearings or trunnions c and d, or may have a spindle or
equivalent passing through them or may be otherwise suitably bung. Preferably
the opening F is formed in the top of the cover A and the valve C when upon its
seat and closed, hangs vertically downwards so that its back or the portion facing
the end of the cylinder E lies flat in a vertical plane, and the piston can be moved
to the end of its stroke against the valve and the space between the piston and
valve can be absolutely gauged by looking through the opening F, or inserting a
distance piece or the like; a very important point being that the engineer can
look straight between the valve and the piston and thus absolutely see what
clearance there is. Also if necessary the effect in working can be seen by this
means.
To prevent chattering and generally to regulate the moving of the valve, each
valve, whether the inlet C or the outlet D, is connected by a link G or equivalent
with a suitable slide or bearing which may be conveniently formed, as a cylinder H
and piston H, each piston being attached to a rod H2 which is made of suitable
length. These reciprocate with the movement of the valves, and the valves are
steadied, controlled and buffered through the agency of these rods H³ and of
devices connected therewith.
The rod H2 of the inlet valve C is carried to a suitable distance and there
caused to pass through a friction or brake device 1 by which a certain brake
resistance or absence of freedom can be imparted to the valve which is thus
prevented from chattering and caused to move smoothly throughout its course,
besides being adaptable while the engine is at work to the varying conditions of
speed and pressure, and also controlled by springs or rubber blocks which may be
arranged upon or in connection with the previously mentioned brake device. These
springs or rubber blocks will act to a considerable extent to buffer the valve as it
approaches its seat and also to help it off its seat again when the piston moves

page_text: upon its return stroke. J is a spring abutting against the washer j and nut j¹ and
against the crosshead K. This spring is employed mainly to moderate the violence
of the sudden opening of the valve and assist in returning it to its face. The cross-
head K is supported by two long bolts or screwed standards L projecting from the
valve chest or cover A. B.
The details of the braking device I aforesaid may be very considerably varied
without departing from the spirit of the invention, but an arrangement which gives
good results consists of crosshead M supported as well as the crosshead K by the
standards L, bolted onto the split cover or chest A, a suitable bearing N which
may be formed of two steps, a spring i or other springy or cushioning device, and
a screw or equivalent for applying and regulating the pressure. If desired
instead of plain bearings one or even both may be formed by rollers N¹ or
equivalent, the pressure of which upon the bar or rod H2 connecting with the valve
and the ease with which they revolve can be varied at will and whilst the engine is
at work. The bar H2 may be round, or if preferred it may be flattened (Figures 4,
5, 8 and 9) so as to provide a certain amount of spring or adaptability whereby it
can accommodate itself to any dropping of the valve out of aligument owing to the
wearing of the parts. This arrangement would also facilitate the original setting
of the parts. Sérews O (Figures 2, 3, 4 and 5) may be employed in conjunction
with the screw to adjust the bearings N of the brake device and secure the
alignment or to prevent straining or twisting due to the parts working out of
alignment, and also for moving the bearings N of the brake devices together or
apart so as to increase or decrease the pressure and braking effect and as these
parts are all outside the cover they are readily accessible when the engine
is at work. In the examples shown in Figures 1, 6, 7, 8 and 9, the screws
dispensed with.
are
To increase or provide the buffering arrangement for the valve, we prefer to
have upon the piston rod H2 or some other suitable part, flanges which are
preferably in the form of nuts P & Q and provided also with lock nuts P' and Q'
so that their position upon the rod H2 may be adjusted as required. These flanges
are so arranged that at the end of the valve stroke in either direction, one or other
of these flanges P and Q will come into contact with rubber blocks or buffers R
suitably arranged between said flanges and the crossheads Kand-M and having
sufficient resiliency or compression and expansion movement to check the valve as
it approaches the end of its stroke, but nevertheless. to allow it to fully bear upon
its seat when the pressure comes upon it. By these means- the valve is prevented
from banging on to its seat, but is nevertheless allowed to sit fairly upon it: This
in conjunction with the braking device and the springs controls in every respect
the valve, allowing it full freedom and delicacy of movement, while at the same
time preventing chattering or undue movement and enabling it either automatically.
to accommodate itself to variations in speed or pressure due to the- working
conditions, or this accommodation can be promptly provided by the attendant
adjusting the devices provided for the purpose.
The above devices are usually only employed in connection with the inlet valve.
In the outlet valve there is much less tendency to chatter, and therefore we do not
generally use the brake device I, though of course it may be used' if so desired.
We usually, use however only the spring J and buffering arrangement above
described, and employ the friction set up by means of the packing glands S-of the
arrangement set forth in our former Patent No. 13730 of 1884. In buffering the
outlet valve, it is preferable that the rubber buffers R be applied on either side of
the crosshead K for the purpose of checking the valve when it opens and cushioning
it when it approaches its seat. Thus as the valve begins to open it has opposed to
it only the spring J at least compression, as it opens wider, the strength of the
spring increases and the valve comes to rest with the quickly applied and rapidly
increasing buffering action between P and R. In closing, the rod H³ has the full
force of the spring J tending to close it, but this decreases as the valve nears
its seat.
It has the constant resistance of the friction of the parts and' lastly

page_text: as the valve gets in the immediate vicinity of the seat, the buffering takes place.
The puts P and Q being adjustable the amount of opening of the valve can be
regulated.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
1. In engines for compressing air and gases or the like, constructing that portion
which forms the cover of the compressing cylinder and in which the inlet and outlet
valves are located, in two parts such as A and B, each part being bolted together,
besides being bolted on to the end of the cylinder, whereby it is only necessary to
remove one part instead of the whole cover to give access to either the inlet or
outlet valves, substantially as described.
2. The arrangement for giving accessibility to the inlet and outlet valves of
engines for compressing air or gases or the like, and enabling the distance between
the piston and valves to be absolutely gauged without taking off the cylinder cover,
namely forming in the compressing cylinder cover in which the inlet and outlet.
vaives are located, or in the part cover, an opening sufficiently large for a valve to
pass through, and closing this opening by a suitable cover or bonnet, which is
fastened to it by bolts or otherwise in such a manner that the cover can be removed
when required, substantially as and for the purposes described.
3. In apparatus for preventing chattering and generally to regulate the moving
of the valves of air compressing engines or the like, the use of an adjustable friction
or brake device such as described, this said device being applied to a rod or
spindle linked or otherwise coupled to the valve, whereby any required brake
resistance or absence of freedom can be imparted to the valve and the same can be
adjusted whilst the engine is at work to the varying conditions of speed and
pressure substantially as described.
4. The general combined arrangement or construction of parts forming our
improved apparatus for preventing chattering and ensuring the smooth operation of
the valves, substantially as set forth so far as it differs from our former inventions
set forth in our prior Patents.
5. The combined valve chest and cylinder cover constructed and arranged
substantially as described with reference to Figures 1, 10, 12 and 13 of the
accompanying drawings and for the purpose specified.
Dated this 26th day of March 1895.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.