Improvements in Valve Mechanism of Steam or other Fluid Pressure Pumping Engines.
Year: 1893

page_text: Date of Application, 22nd Apr., 1893
Complete Specification Left, 22nd Jan., 1894-Accepted, 17th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Valve Mechanism of Steam or other Fluid Pressure
Pumping Engines.
I, WILLIAM CAMERON of Maryport in the County of Cumberland Mechanical
Engineer do hereby declare the nature of this invention to be as follows:
This invention relates to the valve mechanism of direct acting pumping engines
and has for its object the means whereby greater economy in the use of the
working fluid is attained, the securing of certainty of action in the working of the
distributing valve, the cushioning of the distributing valve or its driving piston and
the maintenance of a definite stroke of the engine piston especially when the
engine is exhausting into a condenser.
The distributing valve or valves of the engine are moved by steam or other
fluid pressure during the regular working of the engine and are moved or driven
by pistons or piston which may be formed in the same casting and contained in the
same valve casing as the distributing valve of the engine; but not necessarily so.
The steam supply to these pistons or piston is controlled by an auxiliary valve
which is operated from any suitable moving part of the engine.
At each end of the piston driving the distributing valve of the engine hereafter
called the engine valve, I form a projection or piston of a smaller diameter.
These projections work into chambers hereafter called the air chambers which are
suitably opened to the atmosphere at certain positions of the travel of the
projections.
When the engine piston has reached a point a little beyond its mid travel the
auxiliary valve opens communication between one end of the casing containing
the piston driving the engine valve and the exhaust passage or port. Immediately
this occurs the equilibrium existing in the casing between the ends of the piston is
destroyed and the air which has been compressed in the air chamber during the
previous stroke drives over the piston of the engine valve and compresses the air
contained in the air chamber at the other end of the casing until the pressures are
equal in both chambers. The piston and the engine valve are now brought to a
standstill and the steam supply to the engine cylinder is cut off, thus allowing the
remainder of the engine stroke to be completed by the expansion of the imprisoned
fluid. The exhaust port is still however partly open. As the engine piston
approaches the end of its travel the auxiliary valve admits steam to the casing
containing the piston driving the engine valve which drives the engine valve further
over completing its travel. This further movement closes the exhaust and open
the steam ports thus cushioning the engine piston and admitting steam to the
engine cylinder. The piston driving the engine valve is cushioned and brought to
rest by the air in the air chamber at that end of the casing towards which the
valve is travelling being compressed until the pressure of the air balances the steam
pressure acting on the piston driving the engine valve. The engine valve therefore
remains stationary until this balance is destroyed by the auxiliary valve opening
communication between that end of the casing containing the steam and the
exhaust port. This occurs as before stated when the engine piston has reached a
point a little beyond its mid travel.
Two or more distributing valves may be operated by one piston with is projections
and air chambers and auxiliary valve this would occur in connection with compounds
& multi-compound engines.
Dad his 20th J L A11002

page_text: Improvements in Valve Mechanism of Steam or other Fluid Pressure.
Pumping Engines.
I WILLIAM CAMERON of Maryport in the County of Cumberland Mechanical
Engineer 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 the valve mechanism of direct acting pumping engines
and has for its object the means whereby greater economy in the use of the working
fluid is attained the securing of certainty of action in the working of the
distributing valve the cushioning of the distributing valve or its driving piston and
the maintenance of a definite stroke of the engine piston especially when the
engine is exhausting into a condenser.
The distributing valve or valves are moved by steam or other fluid pressure
during the regular working of the engine and are moved or driven by pistons or
piston which may be formed in the same casting and contained in the same casing
as the distribution valve of the engine but not necessarily so.
The steam supply to these pistons or piston is controlled by an auxiliary valve
which is operated from any suitable moving part of the engine. At each end of
the piston driving the distributing valve of the engine hereafter called the engine
valve I form a projection or piston of a smaller diameter these projections work
into chambers hereafter called the air chambers which are suitably opened to the
atmosphere at certain positions of the travel of the projections.
When the engine piston has reached a point a little beyond its mid travel the
auxiliary valve opens communication between one end of the casing containing
the piston driving the engine valve and the exhaust passage or port, immediately
this occurs the equilibrium existing in the casing between the ends of the piston is
destroyed and the air which has been compressed in the air chamber during the
previous stroke drives over the piston of the engine valve and compresses the air
contained in the air chamber of the other end of the casing until the pressures are
equal in both chambers. The piston and the engine valve are now brought to a
standstill and the steam supply to the engine cylinder is cut off, thus allowing the
remainder of the engine stroke to be completed by the expansion of the imprisoned
fluid. The exhaust port is still however partly open. As the engine piston
approaches the end of its travel the auxiliary valve admits steam to the casing
containing the piston driving the engine valve which drives the engine valve
further over completing its travel, this further movement closes the exhaust and
opens the steam ports thus cushioning the engine piston and admitting steam to the
engine cylinder.
The piston driving the engine valve is cushioned and brought to rest by the air
in the air chamber at that end of the casing towards which the valve is travelling
being compressed until the pressure of the air balances the steam pressure acting
on the piston driving the engine valve. The engine valve therefore remains
stationary until this balance is destroyed by the auxiliary valve opening
communication between that end of the casing containing the steam, and the
exhaust port. This occurs as before stated when the engine piston has reached a
point a little beyond its mid travel.
Two or more distributing valves may be operated by one piston with its
projections and air chambers and auxiliary valve; this would occur in connection
with compound or multi-compound engines.
The annexed drawings shew how my said invention may conveniently be put into
practice.

page_text: auxiliary valve being of the flat disc type.
Fig. 2 Sheet I shews a cross section.
Fig. 3 Sheet 1 is a sectional plan shewing the air chambers and auxiliary motive
fluid passages.
Fig. 4 Sheet 1 is a diagramatic view shewing on a larger scale the auxiliary
valve with its passages and ports.
Fig. 5 Sheet 1 shews one method of attaching the spindle for driving the
auxiliary valve to a swinging lever which is connected to a moving part of the
engine.
Fig. 6 Sheet 1 is an elevation of the valve spindle.
Fig. 7 Sheet 1 is a cross section of the valve spindle shewing lugs or projections
for the purpose of giving the engine valve and its driving pistons a slight oscillating
or rocking movement.
Fig. 1 Sheet 2 shews a arrangement in which the piston for driving the engine
valves or valve and the air piston are each contained in separate casings.
Fig. 2 Sheet 2 is a sectional elevation of the piston for driving the engine valves
with its auxiliary valve and air piston and chamber.
Fig. 3 Sheet 2 is an enlarged section of one form of the auxiliary valve shewing
the means whereby the lap may be increased or decreased in order that the cut off
of the engine valve may be varied.
Fig. 4 Sheet 2, is an end clevation of the auxiliary valve shewn in Fig. 3
Sheet 2.
Fig. 1 to 4 inclusive Sheet 3 shew various sections illustrating my improvements
the auxiliary valve being of the circular slide type.
Figs. 5 & 6 Sheet 3 shew sections of the circular slide valve.
Figs. 7 to 10 inclusive Sheet 3 shew various sections according to my improve-
ments, the main valve or engine valve with its driving pistons being constructed
so as to act as its own auxiliary valve.
Figs. 11 to 13 inclusive Sheet 3 shew various sections according to my improve-
ments the auxiliary valve being of the piston type.
Throughout the drawings like letters indicate corresponding parts.
In order that my said invention may be clearly understood I will now proceed to
describe the action of my improved mechanism.
Referring to Fig. 1 Sheet 1, the ends of the engine or distributing valve are
formed into pistons and on the ends of these pistons, projections or pistons are
formed which work into the air chambers or cylinders cc 1. The steam or other motive
Huid enters at e, the exhaust outlet being at n Figs. 1 & 2. Steam is admitted to the
ends of the engine cylinder alternately by the passages a a 1 and by corresponding
ports 1 in the engine valve B. The engine piston is shewn moving from right to
left steam being admitted by the passage a and exhausted from the cylinder by the
passage a 1.
When the piston has reached a point a little beyond half stroke or
thereby the auxiliary valve which has since the commencement of this stroke
remained stationary owing to the slot in the lever shewn in Fig. 5 Sheet 1 now
receives motion from the swinging lever Fig. 5 owing to the extremity of the slot
coming in contact with the pin in lever k Figs. 2, 5 & 6 immediately after or
thereabout the communication existing between the motive fluid duct g 2 Fig. 4 in
the auxiliary valve and the passage g is closed at the same time the communication
existing between the exhaust duct 94 and the passage g 1 is also closed and the
exhaust go is put into communication with the passage this allows the motive
fluid contained in the right hand end of the engine valve casing to pass by the
exhaust duct g 6 Fig. 4 into the common exhaust passagen Fig. 2. The equilibrium
hitherto existing between the ends of the valve casing that is between the motive
fluid then contained in the right hand end of the valve casing and the compressed
air in the air chamber c, is thus destroyed. The air pressure drives over the
engine valve B closing or partially closing the passage a as the case may be and
by the movement compressing the air contained in the air chamber c which has

page_text: entered by the duct d. The travel of the engine valve B continues until
the air pressures in the air chambers e el balance each other bringing the
engine valve B temporarily to rest; the piston is still however travelling in the
direction of the arrow and is still driving the auxiliary valve bringing the motive
fluid duct 3 Fig. 4 into communication with the passage 1 which is established
at a predetermined point before the piston completes its stroke, on which occurrence
motive fluid is admitted to the left hand end of the valve casing which drives over
the engine valve B completing its unfinished travel. The valve B is brought to
rest by the rise of pressure in the air chamber c due to the further compression of
the imprisoned air, which now balances the pressure exerted by the motive fluid
on the other end of the valve B. The completion of the engine valve's B travel
brings the port 61 into communication with the passage a 1 and allows the motive
fluid to enter into the left hand end of the engine cylinder for the purpose of
cushioning and reversing the piston. On the completion of the stroke from right
to left and when the piston has reached mid travel or thereby on its travel from
left to right a similiar succession of movements are gone through whereby similiar
ducts and passages lying on opposite sides of the vertical centre line of the valves
are brought into operation by the same means and for the same purpose as described
above.
It will be apparent that the engine valve will be quietly brought to rest at each end
of its travel by the air compressed in the chambers c1c and that indepentent of
the pressure, then existing in the end of the valve casing toward which the end
valve is supposed to be moving, being 3 or 15 lbs. per square inch.
It will also be apparent that the efficiency attained by using air is greater than
can possibly be reached by steam when used for the same purpose, as the air will
give practically out during the return stroke the energy stored during compression,
also by the use of air chanibers the mechanism is much simplified there being no
complicated valves and ports required for the purpose of bringing the valve
to rest.
Fig. 2 Sheet 1 shews clearly the auxiliary valve and the method I prefer to
attach the valve spindle i to the swinging lever 1, in this particular case, and which
receives its motion from the piston rod. The handle which is secured to the
pin m 1 Fig. 5, 6 & 2 may be used for bandling the engine in starting, the pin m 1.
being secured to the lever k Fig. 6. The slot shewn in Fig. 5 enables the auxiliary
valve to rest during the early portion of each stroke and allows of the engine
starting from practically any position of the stroke. The same result may be
attained by a proper disposal of exhaust and motive fluid ducts in the auxiliary
valve whereby the exhaust ducts 4 5 are not allowed to communicate with
the passages 1 &
until the engine piston has reached a point about mid stroke.
Figs. 6 & 7 Sheet 1 shew details of the valve spinille this spindle may be
connected to the auxiliary valve in any suitable manner.
g
The oscillating or rocking movement given to the engine valve B by the lugs o, p
Fig. 6 & 7 is simply for the purpose of easing the valve should it stick fast at any
time in starting.
Referring to Sheet 2 of the accompanying drawings. The piston which drives
the engine valve is in this combination in a separate casing the air chamber is also
separate, and its piston is connected to the driving piston B by a rod passing
through stuffing boxes, a prolongation of this rod couples the driving piston to the
engine valves eel. The movement of the driving piston B and therefore of the
valves which are ordinary slide valves controlling the admittance to and
exhaust from the high and low pressure cylinders of a compound tandem engine is
in this particular case controlled of an auxiliary valve of the piston type but it
will be readily apparent to those acquainted with the art that the piston valve could
be replaced by a slide valve or plate admitting motive fluid to and exhausting from
the driving piston cylinder in a similiar manner to the piston valve presently to be
described.
It will also be apparent that any of the hereafter described auxiliary valves

page_text: or the auxiliary valve described in connection with Sheet 1 of the annexed drawings
may be used with their arrangement of ducts and passages.
The motive fluid enters at the ends of the auxiliary valve casing at e, e
Fig.
i
& 2 Sheet 2 the exhaust is passed into the centre and led away in any convenient
manner. For the convenience of manufacture bushes are inserted at each end of
the auxiliary valve casing; in each of these bushes ducts are cut g2, g3 being
motive fluid ducts and 94, 95 Fig. 2 Sheet 2 exhaust duets in this way the piston
valve fis made to command the passages g 1 g.
When the piston of the engine is travelling in the direction of the arrow Figs. 1
& 2 steam is entering by the duct g 2 and has driven the piston B to the extremity
of its stroke, the exhaust having passed out by duct 94 into the atmosphere or
condenser.
During the movement of the piston B from right to left, the air contained
in the left hand end of the air chamber c has been compressed and balances the
motive fluid pressure acting on the piston B. The engine piston is travelling from
right to left and when it reaches about the centre of its travel the piston valve f
being connected through the spindle i to the engine piston rod in the manner before
described in connection with Sheet 1 of the annexed drawings begins to move and
closes the motive fluid duct g 2 and the exhaust duct 94 on moving further the
exhaust duct g 5 is opened, the air pressure in the air chamber c drives the piston B
and the engine valves v, v1 from left to right until equilibrium is established or
thereabout or both sides of the air piston in the air chamber c. The ports on the
right hand of the engine cylinder will now be partially or wholly closed depending
on the arrangement of the lap on the engine and auxiliary valves; in any case the
exhaust port is still open and on the engine piston arriving at a predetermined
point before the end of its stroke the motive fluid duct g 3 is opened. The motive
fluid thus is allowed to enter the driving piston cylinder driving further over the
piston B and the valves 1 completing their travel. This further movement of
the piston B and the air piston e causes a rise of air pressure in the air chamber
which quietly brings the piston B to rest.
The engine valves v, v 1 Fig. 1 Sheet 2 are now over to the extremity of their
travel the ports on the left hand being open to the motive fluid and those on the right
hand open to the exhaust. This brings the engine piston to rest and reverses its
movement which will now be from left to right.
On the piston of the engine arriving at about mid travel the auxiliary valve is
caused to move from right to left the result of which movement is the cushioning
and reversing of the engine piston; on its arrival at the end of its travel towards
the right in the same manner and by the same means as described in connection
with the movement of the engine piston from right to left.
Fig. 3 & 4 Sheet 2 shew a modification of the piston valve whereby the motive
fluid and exhaust lap may be altered thus enabling the point of cut off to be varied
in the engine cylinders in the following manner; by rotating the hand wheel e
Fig. 3 in such a direction as will cause the ends of the piston valve ffl to come
further apart by means of the right and left hand screws on the valve spindle y
Fig. 3. By this means the motive fluid ducts g 2 & g 3 Fig. 2 Sheet 2 will be closed
earlier than formerly and the exhaust ducts g4 & 95 opened sooner; this allows
the compressed air in the air chamber c to drive over the engine valves » & el
earlier thus cutting off the steam from the engine at any earlier period of the
stroke. It will be seen that the motive fluid lap has been increased and therefore
the interval of time between the movement of the piston B and the engine valves u
& 1 by the compressed air and the final movement by the motive fluid has been
increased.
It will apparent that flat plates may also be used in this case without any
disadvantage other than increased frictional resistance. It will be apparent that
instead of using a separate driving piston and cylinder and separate air chamber or
cylinder I may couple one or more distribution or engine valves by means of rods

page_text: and stuffing boxes to the engine or distribution valve described in connection with
and shewn in Sheet 1 of the annexed drawings whose ends perform the functions of
the driving piston B in Fig. 2 Sheet 2 properly proportioning the ends of the
valve B Sheet 1 and the air chambers c & 1 Figs. 1, 3, 4 for the purpose of
driving one or more engine valves distributing steam or other motive fluid to
separate cylinders arranged tandem to that cylinder whose casing contains the
driving pistous and air chambers. It will also be apparent that any of the
hereafter mentioned combinations may be coupled up in the same manner and for
the same purpose.
Referring to Sheet 3 of the annexed drawings Figs. 1 to 6 inclusive shew
another combination in which the auxiliary valve is of the circular slide type.
The action of this combination is precisely similar to that before described in
connection with the combination shewn in Sheet 1. The difference between the
two combinations lies in the type of auxiliary valve used. The parts which perform
similiar functions are indicated by like letters and the description given in connec-
tion with the combination shewn in Sheet 1 stands good for the combination shewn
by Figs. 1 to 6 inclusive Sheet 3 of the annexed drawings.
Figs. 7 to 10 inclusive Sheet 3 shew a combination in which the engine valve
with its driving pistons perform the functions of the auxiliary valve in the before-
mentioned combinations besides distributing motive finid to the engine.
The action of this combination is as follows. The engine piston is travelling
from right to left and when it reaches a point in its travel a little beyond half
stroke the engine valve B receives a movement from the spindle i causing the
valve B to turn on its axis so as to close communication between the motive fluid
duct g2 in the valve B and the passage in the liner of the valve casing, at the
same time communication between the exhaust duet g4 in the engine valve B and
the passage 1 in the valve casing liner is closed as the engine piston travels
onward towards the left the valve B is given a further turn bringing the exhaust
duct 5 into communication with the passage 7. On this taking place the
equilibrium hitherto existing between the motive fluid in the right hand end of the
valve casing and the air pressure in the air chamber el is destroyed whereupon
the air pressure in the air chamber c 1 acting on its piston or projection drives over
the valve B towards the right wholly or partially closing the passage a.
Before the
engine piston reaches the end of its stroke the valve B is given a further movement
about its axis placing the motive fluid duct 3 into communication with the
passage 1, thus allowing motive fluid to pass into the left hand end of the engine
valve casing, this drives the valve B completely over and raises the pressure in the
air chamber c until it balances the motive fluid pressure in the left hand end of the
engine valve casing. Motive fluid is thus allowed to enter into the engine cylinder
by the port 1 and the passage a 1 thus cushioning and reversing the engine piston
which now begins its stroke from left to right; upon the piston reaching a point a
little beyond mid stroke the valve B is partially rotated in a direction opposite to
that just described this closes and makes communication with the corresponding
ducts and passages at the opposite ends of the valve B to those already mentioned
when describing the movement of the engine piston from right to left. Motive
fluid is finally admitted into the right hand end of the engine cylinder in the same
manner and by similar means as described for the movement of the engine piston
from left to right.
Fig. 10 is a diagramatic view shewing the valve B as it rests during the travel
of the engine piston from the commencement of the stroke from the right up to
the centre of that stroke or thereby.
Fig. 7 to 10 inclusive shew the valve B as being oscillated by lugs o, p on the
valve spindle it may however be oscillated by other methods as for instance, the
valve spindle i may be provided with a prong or tongue lying in line with the lever!
which is shewn by the dotted line Fig. 10 Sheet 3. The prong or tongue would
lie in the same plane as the axis of the valve B and would engage with an inclined

page_text: slot cut or cast in the valve B the slot. being so inclined to the axis of the valve
that communication between the ducts and passages is closed and opened in proper
order. The beforementioned slot being cut or cast in the top of the valve B would
be a portion of a right hand spiral; on the piston moving from right to left as
indicated by the arrow the prong would cause the valve B to turn towards the left
when the piston is travelling towards the observer closing communication between
the motive fluid duct 2 and the passage 9 and the exhaust duct g4 and the
passage 1 the other movements proceeding as already described in connection
with Figs. 7 to 10 Sheet 3.
The oscillating movement may be given to the valve B in another manner by
securing in the top of the valve casing a prong or projection which engages with
the slot cut or cast in the valve B. If the valve B is given a longitudinal movement
by means of a prong secured to the valve spindle i; the valve B will at the same
time receive a movement round its axis towards the left, if, the slot be part of a
left handed spiral; the movement of the engine piston being from right to left
and the longitudinal movement given to the valve B by the prong is from left to
right.
Figs. 11 to 13, inclusive, Sheet 3 shews a combination in which the auxiliary
valve is of the piston type; motive fluid enters between the ends of the valve fand
is exhausted from the valve casing by passages g6 & 97 Fig. 13 which lead into
the common exhaust in Fig. 12. The movement of the engine piston is com-
municated to the auxiliary valve in the manner before mentioned and when the
piston reaches a point a little beyond mid travel it causes the piston valve to close
the motive fluid duct g 3 (the travel of the engine piston being in the direction
indicated by the arrow Fig. 13) and the exhaust duct 5 and open the exhaust
duct g 4 whereupon the action is similiar to that already described in connection
with Sheet 1 of the annexed drawings.
In some cases it is advisable to fix air cocks at each end of the air chambers in
order to facilitate the adjustment of the engine valve's travel by regulating the
opening of the air cocks these cocks are only used when starting or when the engine
is very much underload. The engine may be driven by steam, air or water under
pressure and may be used for pumping and compressing air as well as for pumping
water.
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
1st. In direct acting pumping engines. The combination of an air chamber or
chambers with piston or pistons, a motive fluid operated piston or pistons, driving
one or more engine or distributing valves, and an auxiliary valve or its equivalent
substantially as and for the purpose set forth.
2nd. In direct acting pumping engines. The combination of an air chamber or
chambers with piston or pistons, a motive fluid operated piston or pistons, driving
one or more engine or distributing valves, and an auxiliary valve or its equivalent
substantially as shewn by the annexed drawings.
Dated this 20th day of January 1894.
WM. CAMERON.

page_text: Date of Application, 22nd Apr., 1893
Complete Specification Left, 22nd Jan., 1894-Accepted, 17th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Valve Mechanism of Steam or other Fluid Pressure
Pumping Engines.
I, WILLIAM CAMERON of Maryport in the County of Cumberland Mechanical
Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to the valve mechanism of direct acting pumping engines
and has for its object the means whereby greater economy in the use of the
working fluid is attained, the securing of certainty of action in the working of the
distributing valve, the cushioning of the distributing valve or its driving piston and
the maintenance of a definite stroke of the engine piston especially when the
engine is exhausting into a condenser.
The distributing valve or valves of the engine are moved by steam or other
fluid pressure during the regular working of the engine and are moved or driven
by pistons or piston which may be formed in the same casting and contained in the
same valve casing as the distributing valve of the engine; but not necessarily so.
The steam supply to these pistons or piston is controlled by an auxiliary valve
which is operated from any suitable moving part of the engine.
At each end of the piston driving the distributing valve of the engine hereafter
called the engine valve, 1 form a projection or piston of a smaller diameter.
These projections work into chambers hereafter called the air chambers which are
suitably opened to the atmosphere at certain positions of the travel of the
projections.
When the engine piston has reached a point a little beyond its mid travel the
auxiliary valve opens cominunication between one end of the casing containing
the piston driving the engine valve and the exhaust passage or port. Immediately
this occurs the equilibrium cxisting in the casing between the ends of the piston is
destroyed and the air which has been compressed in the air chamber during the
previous stroke drives over the piston of the engine valve and compresses the air
contained in the air chamber at the other end of the casing until the pressures are
equal in both chambers. The piston and the engine valve are now brought to a
standstill and the steam supply to the engine cylinder is cut off, thus allowing the
remainder of the engine stroke to be completed by the expansion of the imprisoned
fluid. The exhaust port is still however partly open. As the engine piston
approaches the end of its travel the auxiliary valve admits steam to the casing
containing the piston driving the engine valve which drives the engine valve further
over completing its travel. This further movement closes the exhaust and open
the steam ports thus cushioning the engine piston and admitting steam to the
engine cylinder. The piston driving the engine valve is cushioned and brought to
rest by the air in the air chamber at that end of the casing towards which the
valve is travelling being compressed until the pressure of the air balances the steam
pressure acting on the piston driving the engine valve. The engine valve therefore
remains stationary until this balance is destroyed by the auxiliary valve opening
communication between that end of the casing containing the steam and the
exhaust port. This occurs as before stated when the engine piston has reached a
point a little beyond its mid travel.
Two or more distributing valves may be operated by one piston with is projections
and air chambers and auxiliary valve this would occur in connection with compounds
& multi-compound engines.
Dated this 20th dor of Anil 1002

page_text: COMPLETE SPECIFICATION.
Improvements in Valve Mechanism of Steam or other Fluid Pressure
Pumping Engines.
I WILLIAM CAMERON of Maryport in the County of Cumberland Mechanical
Engineer 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 the valve mechanism of direct acting pumping engines
and has for its object the means whereby greater economy in the use of the working
fluid is attained the securing of certainty of action in the working of the
distributing valve the cushioning of the distributing valve or its driving piston and
the maintenance of a definite stroke of the engine piston especially when the
engine is exhausting into a condenser.
The distributing valve or valves are moved by steam or other fluid pressure
during the regular working of the engine and are moved or driven by pistons or
piston which may be formed in the same casting and contained in the same casing
as the distribution valve of the engine but not necessarily so.
The steam supply to these pistons or piston is controlled by an auxiliary valve
which is operated from any suitable moving part of the engine. At each end of
the piston driving the distributing valve of the engine bereafter called the engine
valve I form a projection or piston of a smaller diameter these projections work
into chambers hereafter called the air chambers which are suitably opened to the
atmosphere at certain positions of the travel of the projections.
When the engine piston has reached a point a little beyond its mid travel the
auxiliary valve opens communication between one end of the casing containing
the piston driving the engine valve and the exhaust passage or port, immediately
this occurs the equilibrium existing in the casing between the ends of the piston is
destroyed and the air which has been compressed in the air chamber during the
previous stroke drives over the piston of the engine valve and compresses the air
contained in the air chamber of the other end of the casing until the pressures are
equal in both chambers. The piston and the engine valve are now brought to a
standstill and the steam supply to the engine cylinder is cut off, thus allowing the
remainder of the engine stroke to be completed by the expansion of the imprisoned
fluid. The exhaust port is still however partly open. As the engine piston
approaches the end of its travel the auxiliary valve admits steam to the casing
containing the piston driving the engine valve which drives the engine valve
further over completing its travel, this further movement closes the exhaust and
opens the steam ports thus cushioning the engine piston and admitting steam to the
engine cylinder.
The piston driving the engine valve is cushioned and brought to rest by the ai
in the air chamber at that end of the casing towards which the valve is travelling
being compressed until the pressure of the air balances the steam pressure acting
on the piston driving the engine valve. The engine valve therefore remains
_ stationary until this balance is destroyed by the auxiliary valve opening
communication between that end of the casing containing the steam, and the
_ exhaust port. This occurs as before stated when the engine piston has reached
point a little beyond its mid travel.
Two or more distributing valves may be operated by one piston with it
projectious and air chambers and auxiliary valve; this would occur in connectio
with compound or multi-compound engines.
The annexed drawings shew how my said invention may conveniently be put int

page_text: Fig. 1 Sheet 1 shews a sectional elevation of one form of my invention the
auxiliary valve being of the flat disc type.
Fig. 2 Sheet 1 shews a cross section.
Fig. 3 Sheet 1 is a sectional plan shewing the air chambers and auxiliary motive
fluid passages.
Fig. 4 Sheet 1 is a diagramatic view shewing on a larger scale the auxiliary
valve with its passages and ports.
Fig. 5 Sheet 1 shews one method of attaching the spindle for driving the
auxiliary valve to a swinging lever which is connected to a moving part of the
engine.
Fig. 6 Sheet 1 is an elevation of the valve spindle.
Fig. 7 Sheet 1 is a cross section of the valve spindle shewing lugs or projections
for the purpose of giving the engine valve and its driving pistons a slight oscillating
or rocking movement.
Fig. 1 Sheet 2 shews a arrangement in which the piston for driving the engine
valves or valve and the air piston are each contained in separate casings.
Fig. 2 Sheet 2 is a sectional elevation of the piston for driving the engine valves
with its auxiliary valve and air piston and chamber.
Fig. 3 Sheet 2 is an enlarged section of one form of the auxiliary valve shewing
the means whereby the lap may be increased or decreased in order that the cut off
of the engine valve may be varied.
Fig. 4 Sheet 2, is an end elevation of the auxiliary valve shewn in Fig. 3
Sheet 2.
Fig. 1 to 4 inclusive Sheet 3 shew various sections illustrating my improvements
the auxiliary valve being of the circular slide type.
Figs. 5 & 6 Sheet 3 shew sections of the circular slide valve.
Figs. 7 to 10 inclusive Sheet 3 shew various sections according to my improve-
ments, the main valve or engine valve with its driving pistons being constructed
so as to act as its own auxiliary valve.
Figs. 11 to 13 inclusive Sheet 3 shew various sections according to my improve-
ments the auxiliary valve being of the piston type.
Throughout the drawings like letters indicate corresponding parts.
In order that my said invention may be clearly understood I will now proceed to
describe the action of my improved mechanism.
Referring to Fig. 1 Sheet 1, the ends of the engine or distributing valve are
formed into pistons and on the ends of these pistons, projections or pistons are
formed which work into the air chambers or cylinders cc 1. The steam or other motive
fluid enters at e, the exhaust outlet being at n Figs. 1 & 2. Steam is admitted to the
ends of the engine cylinder alternately by the passages a a 1 and by corresponding
ports in the engine valve B. The engine piston is shewo moring from right to
left steam being admitted by the passage a and exhausted from the cylinder by the
passage a 1.
When the piston has reached a point a little beyond half stroke or
thereby the auxiliary valve which has since the commencement of this stroke
remained stationary owing to the slot in the lever shewn in Fig. 5 Sheet 1 now
receives motion from the swinging lever 1 Fig. 5 owing to the extremity of the slot
coming in contact with the pin in lever k Figs. 2, 5 & 6 immediately after or
thereabout the communication existing between the motive fluid duct g 2 Fig. 4 in
the auxiliary valve and the passage g is closed at the same time the communication
existing between the exhaust duct 94 and the passage 91 is also closed and the
exhaust go is put into communication with the passage g this allows the motive
fluid contained in the right hand end of the engine valve casing to pass by the
xhaust duct g6 Fig. 4 into the common exhaust passagen Fig. 2. The equilibrium
hitherto existing between the ends of the valve casing that is between the motive
Huid then contained in the right hand end of the valve casing and the compressed
ir in the air chamber c, is thus destroyed. The air pressure drives over the
engine valve B closing or partially closing the passage a as the case may be and
by the movement compressing the air contained in the air chamber c which has

page_text: entered by the duct d. The travel of the engine valve B continues until
the air pressures in the air chambers ce balance each other bringing the
engine valve B temporarily to rest; the piston is still however travelling in the
direction of the arrow and is still driving the auxiliary valve bringing the motive
fluid duct g 3 Fig. 4 into communication with the passage g 1 which is established
at a predetermined point before the piston completes its stroke, ou which occurrence
motive fluid is admitted to the left hand end of the valve casing which drives over
the engine valve B completing its unfinished travel. The valve B is brought to
rest by the rise of pressure in the air chamber e due to the further compression of
the imprisoned air, which now balances the pressure exerted by the motive fluid
on the other end of the valve B. The completion of the engine valve's B travel
brings the port 1 into communication with the passage al and allows the motive
fluid to enter into the left hand end of the engine cylinder for the purpose of
cushioning and reversing the piston. On the completion of the stroke from right
to left and when the piston has reached mid travel or thereby on its travel from
left to right a similiar succession of movements are gone through whereby similiar
ducts and passages lying on opposite sides of the vertical centre line of the valves
are brought into operation by the same means and for the same purpose as described
above.
It will be apparent that the engine valve will be quietly brought to rest at each end
of its travel by the air compressed in the chambers 1c and that indepentent of
the pressure, then existing in the end of the valve casing toward which the end
valve is supposed to be moving, being 3 or 15 lbs. per square inch.
It will also be apparent that the efficiency attained by using air is greater than
can possibly be reached by steam when used for the same purpose, as the air will
give practically out during the return stroke the energy stored during compression,
also by the use of air chambers the mechanism is much simplified there being no
complicated valves and ports required for the purpose of bringing the valve
to rest.
m l
Fig. 2 Sheet 1 shews clearly the auxiliary valve and the method I prefer to
attach the valve spindle i to the swinging lever 1, in this particular case, and which
receives its motion from the piston rod. The handle m which is secured to the
pin m1 Fig. 5, 6 & 2 may be used for handling the engine in starting, the pin
being secured to the lever A Fig. 6. The slot shewn in Fig. 5 enables the auxiliary
valve to rest during the early portion of each stroke and allows of the engine
starting from practically any position of the stroke. The same result may be
attained by a proper disposal of exhaust and motive fluid ducts in the auxiliary
valve whereby the exhaust ducts 475 are not allowed to communicate with
the passages 1 & until the engine piston has reached a point about mid stroke
Figs. 6 & 7 Sheet 1 shew details of the valve spindle this spindle may be
connected to the auxiliary valve in any suitable manner.
The oscillating or rocking movement given to the engine valve B by the lugs 0, p
Fig. 6 & 7 is simply for the purpose of easing the valve should it stick fast at any
time in starting.
Referring to Sheet 2 of the accompanying drawings. The piston which drives
the engine valve is in this combination in a separate casing the air chamber is also
separate, and its piston is connected to the driving piston B by a rod passing
through stuffing boxes, a prolongation of this rod couples the driving piston to the
engine valves 1. The movement of the driving piston B and therefore of the
valves which are ordinary slide valves controlling the admittance to and
exhaust from the high and low pressure cylinders of a compound tandem engine is
in this particular case controlled of an auxiliary valve of the piston type but it
will be readily apparent to those acquainted with the art that the piston valve could
be replaced by a slide valve or plate admitting motive fluid to and exhausting from
the driving piston cylinder in a similiar manner to the piston valve presently to be
described.
. It will also be apparent that any of the hereafter described auxiliary valves

page_text: r the auxiliary valve described in connection with Sheet 1 of the annexed drawings
ay be used with their arrangement of ducts and passages.
The motive fluid enters at the ends of the auxiliary valve casing at e, e Fig. 1
2 Sheet 2 the exhaust is passed into the centre and led away in any convenient
hanner. For the convenience of manufacture bushes are inserted at each end of
he auxiliary valve casing; in each of these bushes ducts are cut 92, 93 being
way the piston
notive fluid ducts and g 4, g 5 Fig. 2 Sheet 2 exhaust ducts in this
alve f is made to command the passages o g.
1
When the piston of the engine is travelling in the direction of the arrow Figs. 1
2 steam is entering by the duct g 2 and has driven the piston B to the extremity
of its stroke, the exhaust having passed out by duct 94 into the atmosphere or
condenser.
During the movement of the piston B from right to left, the air contained
in the left hand end of the air chamber c has been compressed and balances the
motive fluid pressure acting on the piston B. The engine piston is travelling from
right to left and when it reaches about the centre of its travel the piston valve j
being connected through the spindle i to the engine piston rod in the manner before
described in connection with Sheet 1 of the annexed drawings begins to move and
closes the motive fluid duct g 2 and the exhaust duct g4 on moving further the
exhaust duct g 5 is opened, the air pressure in the air chamber c drives the piston B
and the engine valves v, 1 from left to right until equilibrium is established or
The ports on the
thereabout or both sides of the air piston in the air chamber c.
right hand of the engine cylinder will now be partially or wholly closed depending
on the arrangement of the lap on the engine and auxiliary valves; in any case the
exhaust port is still open and on the engine piston arriving at a predetermined
point before the end of its stroke the motive fluid duct g 3 is opened. The motive
Buid thus is allowed to enter the driving piston cylinder driving further over the
piston B and the valves 1 completing their travel. This further movement of
the piston B and the air piston c causes a rise of air pressure in the air chamber
which quietly brings the piston B to rest.
The engine valves r, r 1 Fig. 1 Sheet 2 are now over to the extremity of their
travel the ports on the left hand being open to the motive fluid and those on the right
hand open to the exhaust. This brings the engine piston to rest and reverses its
movement which will now be from left to right.
On the piston of the engine arriving at about mid travel the auxiliary valve is
caused to move from right to left the result of which movement is the cushioning
and reversing of the engine piston; on its arrival at the end of its travel towards
the right in the same manner and by the same means as described in connection
with the movement of the engine piston from right to left.
Fig. 3 & 4 Sheet 2 shew a modification of the piston valve whereby the motive
fluid and exhaust lap may be altered thus enabling the point of cut off to be varied
in the engine cylinders in the following manner; by rotating the hand wheel
Fig. 3 in such a direction as will cause the ends of the piston valve fil to come
further apart by means of the right and left hand screws on the valve spindle y
Fig. 3. By this means the motive fluid ducts g 2 & 93 Fig. 2 Sheet 2 will be closed
earlier than formerly and the exhaust ducts 94 & 95 opened sooner; this allows
the compressed air in the air chamber c to drive over the engine valves & rl
earlier thus cutting off the steam from the engine at any earlier period of the
stroke. It will be seen that the motive fluid lap has been increased and therefore
the interval of time between the movement of the piston B and the engine valves
& 1 by the compressed air and the final movement by the motive fluid has been
increased.
It will apparent that flat plates may also be used in this case without any
disadvantage other than increased frictional resistance. It will be apparent that
5 instead of using a separate driving piston and cylinder and separate air chamber or
cylinder may couple one or more distribution or engine valves by means of rods

page_text: and stuffing boxes to the engine or distribution valve described in connection with
and shewn in Sheet 1 of the annexed drawings whose ends perform the functions of
the drivit piston B in Fig. 2 Sheet 2 properly proportioning the ends of the
valye B Sheet I and the air chambers & c 1 Figs. 1, 3, 4 for the purpose of
driving one or more engine valves distributing steam or other motive Huid to
separate cylinders arranged tandem to that cylinder whose casing contains the
* Triving pistons and air chambers. It will also be apparent that any of the
Shereafter mentioned combinations may be coupled up in the same manner and for
the same purpose.
Referring to Sheet 3 of the annexed drawings Figs. 1 to 6 inclusive shew
another combination in which the auxiliary valve is of the circular slide type.
The action of this combination is precisely similar to that before described in
connection with the combination shewn in Sheet 1. The difference between the
two combinations lies in the type of auxiliary valve used. The parts which perform
similiar functions are indicated by like letters and the description given in connec-
tion with the combination shewn in Sheet I stands good for the combination shewn
by Figs. 1 to 6 inclusive Sheet 3 of the annexed drawings.
Figs. 7 to 10 inclusive Sheet shew a combination in which the engine valve
with its driving pistons perform the functions of the auxiliary valve in the before-
mentioned combinations besides distributing motive fluid to the engine.
The action of this combination is as follows. The engine piston is travelling
from right to left and when it reaches a point in its travel a little beyond half
stroke the engine valve B receives a movement from the spindle i causing the
valve B to turn on its axis so as to close communication between the motive fluid
duct g2 in the valve B and the passage in the liner of the valve casing, at the
same time comununication between the exhaust duct 4 in the engine valve B and
the passage 1 in the valve casing liner is closed; as the engine piston travels
onward towards the left the valve B is given a further turn bringing the exhaust
duct 5 into communication with the passage On this taking place the
equilibrium hitherto existing between the motive fluid in the right hand end of the
valve casing and the air pressure in the air chamber el is destroyed whereupon
the air pressure in the air chamber c 1 acting on its piston or projection drives over
the valve B towards the right wholly or partially closing the passage a. Before the
engine piston reaches the end of its stroke the valve B is given a further movement
about its axis placing the motive fluid duct g3 into communication with the
passage 1, thus allowing motive fluid to pass into the left hand end of the engine
valve casing, this drives the valve B completely over and raises the pressure in the
air chamber c until it balances the motive fluid pressure in the left hand end of the
engine valve casing. Motive fluid is thus allowed to enter into the engine cylinder
by the port 1 and the passage a 1 thus cushioning and reversing the engine piston
which now begins its stroke from left to right; upon the piston reaching a point a
little beyond mid stroke the valve B is partially rotated in a direction opposite to
that just described this closes and makes communication with the corresponding
ducts and passages at the opposite ends of the valve B to those already mentioned
when describing the movement of the engine piston from right to left. Motive
fluid is finally admitted into the right hand end of the engine cylinder in the ɛame
manner and by similar means as described for the movement of the engine piston
from-left to right.
Fig. 10 is a diagramatic view shewing the valve B as it rests during the travel
of the engine piston from the commencement of the stroke from the right up to
the centre of that stroke or thereby.
Fig. 7 to 10 inclusive shew the valve B as being oscillated by lugs o, p on the
valve spindle it may however be oscillated by other methods as for instance, the
valve spindle i may be provided with a prong or tongue lying in line with the lever!
which is shewn by the dotted line Fig. 10 Sheet 3. The prong or tongue would
lie in the same plane as the axis of the valve B and would engage with an inclined

page_text: lot cut or cast in the valve B the slot. being so inclined to the axis of the valve
hat communication between the ducts and passages is closed and opened in proper
order. The beforementioned slot being cut or cast in the top of the valve B would
be a portion of a right hand spiral; on the piston moving from right to left as
indicated by the arrow the prong would cause the valve B to turn towards the left
when the piston is travelling towards the observer closing communication between
the motive fluid duct 2 and the passage g and the exhaust duct g4 and the
passage g 1 the other movements proceeding as already described in connection
with Figs. 7 to 10 Sheet 3.
The oscillating movement may be given to the valve B in another manner by
securing in the top of the valve casing a prong or projection which engages with
the slot cut or cast in the valve B. If the valve B is given a longitudinal movement
by means of a prong secured to the valve spindle i; the valve B will at the same
time receive a movement round its axis towards the left, if, the slot be part of a
left handed spiral; the movement of the engine piston being from right to left
and the longitudinal movement given to the valve B by the prong is from left to
right.
Figs. 11 to 13, inclusive. Sheet 3 shews a combination in which the auxiliary
valve is of the piston type; motive fluid enters between the ends of the valve fand
is exhausted from the valve casing by passages 6 & 97 Fig. 13 which lead into
the common exhaust in Fig. 12. The movement of the engine piston is com-
municated to the auxiliary valve in the manner before mentioned and when the
piston reaches a point a little beyond mid travel it causes the piston valve to close
the motive fluid duct g3 (the travel of the engine piston being in the direction
indicated by the arrow Fig. 13) and the exhaust duct 5 and open the exhaust
duct g 4 whereupon the action is similiar to that already described in connection
with Sheet 1 of the aunexed drawings.
In some cases it is advisable to fix air cocks at each end of the air chambers in
order to facilitate the adjustment of the engine valve's travel by regulating the
opening of the air cocks these cocks are only used when starting or when the engine
is very much underload. The engine may be driven by steam, air or water under
pressure and may be used for pumping and compressing air as well as for pumping
water.
Having now particularly described and ascertained the nature of iny said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1st. In direct acting pumping engines. The combination of an air chamber or
chambers with piston or pistons, a motive fluid operated piston or pistons, driving
one or more engine or distributing valves, and an auxiliary valve or its equivalent
substantially as and for the purpose set forth.
2nd. In direct acting pumping engines. The combination of an air chamber or
chambers with piston or pistons, a motive fluid operated piston or pistons, driving
one or more engine or distributing valves, and an auxiliary valve or its equivalent
substantially as shewn by the annexed drawings.
Dated this 20th day of January 1894.
GAMEDON
M. CAMERON.
TAT A