Improvements in or relating to Self Acting Valves for Blowing Engines and the like.
Year: 1898

page_text: Date of Application, 7th Dec., 1898
Complete Specification Left, 7th Sept., 1899-Accepted, 7th Oct., 1899
PROVISIONAL SPECIFICATION.
Improvements in or relating to Self Acting Valves for Blowing
Engines and the like.
We, JOHN SCARISBRICK WALKER, THOMAS ASCROFT WALKER, and EDWIN ROBERT
WALKER, all of l'agefield Iron Works, Wigan, in the County of Lancaster,
Engineers, do hereby declare the nature of this invention to be as follows:-
:_
This invention has for its object an arrangement of valve apparatus for blow-
ing engines of large capacity, whereby greater ease of action shall be obtained.
In larger blowing engines at the present time the valves being of great size
cause a very large amount of vibration, also being usually at the side of the
cylinder there is far too much clearance, and waste of power.
Now by our invention an exceedingly small clearance is required. We form
a series of boxes in the cover, and in the bottom of these boxes facing the piston
and with their surfaces in a line with the inside of the cylinder cover we arrange
the valves on their seats. These valves in the case, both of exit and entrance
valves are two or more in number, usually four, and we arrange them with their
seatings at some little distance from the exit on which the valves flap so that
all round the valve seat there shall be a clearance for the air to escape. By
this means comparatively small valves can be used with free exit and entrance
of air. Two or even four valves can be pivotted on one spindle or there can be
a spindle for each valve. All the exit or entrance valves at one end are coupled
by links and levers with each other and with the usual buffering device, and in
order that there may be an exact adjustment of the valves and valve spindles, we
cause each valve spindle to pass through a hole in a bridge picce carried in the
fork, stirrup or end of its respective lever or link.
On the valve spindle are two nuts and check nuts, one pair being on each side
of the bridge piece and between the bridge piece and the nut is a strong helical
spring. By adjusting the nuts, consequently the exact pressure on each of these
springs can be adjusted, and consequently if two valves do not meet absolutely
uniformly the springs can be adjusted until they do. In order to enable the
valve to close without undue shock we connect it with a spindle having a piston
in the end working in a dash pot, but as when the air in the dash pot is strongly
compressed it causes the piston to rebound and thus produce a tremor or quivering
in the valve we arrange a trip device whereby the moment the air has been
tightly compressed and the valve has thus been brought to the stand the trip
device opens a passage for the escape of the air and thus the tremor or quivering
is avoided. The trip device is as follows:-Connected with any suitable moving
portion of the engine, we place a sliding sleeve. Into one end of this sleeve
passes a ram closely fitting it. This sleeve reciprocates once for every reciproca-
tion of the valve. On this sleeve is a spring detent and in the sliding ram is
a notch into which this detent can fit. As the valve presses forward on to the
ram this detent falls into the notch and carries the ram along with it. The ram
is thus pushed down and covers the hole through which air can escape through the

page_text: now
dash pot. As the sleeve further advances the arm on the detent comes in con-
tact with a stationary stop and the detents leaves the notch; the spring which
has through the previous motion been strongly compressed by the ram
shoots the ram backwards thus opening the hole through which air can escape
from the dash pot the moment after this latter has been strongly compressed.
The sleeve now retires to its extreme point and the detent again catches in the
notch and is ready for a fresh action.
1000
Improvements in or relating to Self Acting Valves for Biowing
Engines and the like.
We, JOHN SCARISBRICK WALKER, THOMAS ASCROFT WALKER, and EDWIN ROBERT
WALKER, all 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 has for its object an arrangement of valve apparatus for blow-
ing engines of large capacity, whereby greater ease of action can be obtained.
In large blowing engines at the present time the valves being of great size
cause a very large amount of vibration, also being usually at the side of the
cylinder there is far too much clearance and waste of power. Now by our
present invention an exceedingly small clearance is required.
The invention will be understood from the following description, reference
being had to the accompanying drawings, in which,
Figure 1 is a longitudinal section of a portion of an air compressing cylinder
of a vertical blowing engine, the inlet and outlet valves and the mechanism
connected therewith;
Figure 2, an elevation partly in section of the buffering and trip device as
applied to a horizontal engine;
Figure 3, an end view of the device for liberating the air in the dashpot;
Figure 4, a plan of the buffering device;
Figure 5, an end elevation of the dash pot and other parts.
Referring to Figure 1, A is a cylinder cover forming chests for the inlet and
outlet valves B the compressing cylinder, C the piston rod. In the bottom of
these chests facing the piston, and with their surfaces in line with the inside of
the cylinder cover, we arrange the inlet valves ]) and the outlet valves E and
their valve seats. These valves in the case both of the inlet and outlet valves
are two or more in number, usually four, and the valves we prefer to use are in
the form of hinged valves carried on bearings or trunnions à e, or they may be
otherwise arranged. The seatings of the valves are arranged at some little
distance from the trunnions, on which the valve flap so that all round the valve
seat (when the valve is open) there shall be a clearance for the air to escape.
By this means small valves can be used with free inlet and outlet for air. Two
or even four valves can be pivoted on one spindle d or e, or there can be a spindle
or trunnion for each valve. These valves are sc balanced as to reduce the blows
caused by the pulsating action of the air, when the compressor is at work. The
balancing may be effected in various ways. A simple plan is to apply the usual
buffering device F described in our previous Patents Nos. 448877, 1551, 137308

page_text: and a dash pot P hereafter described to each set of valves, through the crank
levers G and links H and valve spindles D' E' and by this system of linkage,
the valves in each set are coupled together, and balanced, to prevent their dancing
or flapping, when the air is passing through, no matter what velocity the engine
is going at.
Furthermore one or both of the crank levers G may be fitted with
counterweights I. These may be arranged to counterbalance the valve exactly,
or weigh against it with a greater or less weigh or power, and by making the
counter weights adjustable their effect on the valves can be varied at will. Thus
the valves can be placed in exact equilibrium or one may weigh against the
other with a greater or less weight. In order to secure an exact adjustment of
the valves and valve spindles, we cause each valve spindle to pass through a
hole in a bridge piece or pin J carried in the fork stirrup, or end of its crank
lever. On the valve spindles D E¹ are two nuts K and check nuts k, one pair
being on each side of the bridge piece or pin J. Between the pin and the nuts
are strong helical springs L. By adjusting the nuts the exact pressure on each
of the springs can be adjusted, consequently if two valves do not meet absolutely
uniformly, the springs can be adjusted or will adjust themselves till the valves
touch their respective facings or seats. This arrangement is useful if the valves
are not absolutely true on their faces, further if one valve closes, the pressure of
air will close the other valve or valves through the elasticity of the springs. To
further regulate the moving of the valves we provide the usual cushioning
devices M as aforesaid, Figures 2 and 4, and also connect them with spindle N
having a piston at the end working in a dash pot P, as shewn best in Figures 2
& 4 in connection with the horizontal engine, but shewn also in less detail in
Figure 1. This dash pot is designed to take the blow of the sudden opening of
the valves. As however the air in the dash pot is strongly compressed it is
liable to cause the piston O to rebound, and thus produce a tremor or quivering
in the valve. We therefore arrange a trip device whereby the moment the air
has been slightly compressed, and the valve has been brought to the stand, the
trip device opens a passage for the escape of air, and thus the tremor or quivering
is avoided. The trip device which is shown in Figures 1, 2, 3 and 5 inclusive is
as follows:-
Connected with any suitable moving portion of the engines we place a sliding
ram R and on this ram R mount a sleeve Q closely fitting it. This ram R
reciprocates once for every reciprocation of the valve by means of the crank q
and connecting rod q. On this sleeve is a spring detent S and in the sliding
ram R is a notch into which this detent can fit.
As the ram presses back into the sleeve, this detent falls in the notch, &
on the return movement carries the sleeve along with it, which sleeve is connected
with the air valve W by means of the connecting rod Y. The sleeve is thus
pulled down, and the valve W closes the port X through which air would other-
wise escape from the dash pot P. The valve remains closed until the arm T
on the detent comes in contact with the stationary stop U and the detent leaves
the notch, the spring V, which has in the previous motion been strongly com-
pressed, now shoots the sleeve and valve backwards, thus opening the port X
through which air can escape from the dash pot the moment after the spring
has been strongly compressed. Z are regulating escape set screws to allow air to
escape from P and valve chamber 7. The ram moves back to its extreme point,
and the detent again catches in the notch and is ready for a fresh action. It
is obvious that the positions of the sleeve Q and ram R may be reversed, the
sleeve being coupled to the crank q, and the ram coupled by a connecting rod
to the ram or valve W. It is so described in the Provisional Specification and
in fact the one is the obvious equivalent of the other, or the valve W with box Z¹
and its devices can be placed in any other convenient position so long as they
are connected with the dash pot P. 7 are the piston rods of the steam and
air cylinders respectively, and Z³ the coupling therefor. 7 the spring of the
detent S.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. The improvement in self acting valves for the compressing cylinders of
blowing engines or the like, which consists in making them in the form of hinged
or flap valves carried on spindles or trunnions, and in arranging the seating
of the said valves at some little distance from the trunnions in such manner
that when the valves are open they will completely clear the valve seats, whereby
smaller valves can be used than hitherto with free inlet and outlet for air, sub-
stantially as described.
2. In self acting valves for blowing engines, the means for securing an exact
adjustment of the valves, substantially as described.
3. In apparatus for balancing the self acting valves of the compressor cylinders
of blowing engines or the like, in which the mechanism for imparting a brake
resistance or absence of freedom to the valves comprises a piston working in a
dash pot, the device for liberating the air in the said dash pot, which consists
in providing the dash pot with an air valve so connected with any suitable mov-
ing portion of the engines that it will reciprocate once for every reciprocation
of the self acting valves, and in providing also a detent and trip device adapted
at the proper moment to sever the connection of the valve with the moving part
of the engine and enable the valve to shoot backwards by the pressure of a spring,
to open the air outlet, whereby there is a release of the compressd air sub-
stantially as described.
4. The general combined arrangement of parts forming the improved relief
valve with detent and trip device substantially as described.
Dated this 7th dow of Contamhan 1800
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham and London.