IMPROVEMENTS IN WORKING THE SLIDE VALVES OF STEAM PUMPS
Year: 1884

page_text: We JOHN NICHOLAS FLOYD of Cornwall Cottage Murdock Road Handsworth
in the County of Stafford Mechanical Engineer and GEORGE TANGYE of Cornwall
Works Soho in the County of Stafford Manufacturer do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN WORKING THE SLIDE VALVES OF
STEAM PUMPS" to be as follows:-
Our invention consists of the construction and arrangement of parts hereinafter
described for automatically working the slide valves of steam pumps by the action
of the water pressure in the pump barrel or pump cylinder.
We fix outside the pump barrel or pump cylinder and at about its middle two
small cylinders situated a short distance apart the said small cylinders being bolted
together and preserved in the same line by a distance piece between them.
In each of the said small cylinders a piston works hereinafter called the reversing
pistons. These reversing pistons are connected together by a spindle or rod passing
through the distance piece a prolongation of the said spindle or rod being connected
directly to the steam cylinder slide valve: The ends of each small cylinder are in
communication by means of ports or passages with the pump barrel. That port
which is situated at the closed end of each small cylinder we will call the back port
and that situated at the cover end of the cylinder we will call the front port.
When the bucket or piston in the pump barrel is making its stroke say from
left to right and the said bucket has so far advanced as to be between the front
ports of the two small cylinders the position of the parts is as follows:-The two
ports of the right hand cylinder are in communication with the water pressure in
the pump barrel on the right hand side of the bucket and the two ports of the left
hand cylinder are in communication with the vacuum in the pump barrel on the
opposite side of the pump bucket. The right hand reversing piston is at the bottom
of its cylinder and the left hand reversing piston is at the cover end of its cylinder.
The ports of the right hand small cylinder being thus in communication with the
water pressure the said pressure acts on opposite sides of the piston in that cylinder
and the last named piston is consequently in equilibrium and the slide valve is
stationary. As the pump bucket advances in the direction indicated that is from
left to right it first covers the front port of the right hand cylinder and afterwards
uncovers it and puts the exhaust side of the bucket in communication with the cover
end of the said cylinder. The water is thereby exhausted from the said cover and of
the cylinder into the pump barrel on the vacuum side of the bucket. The reversing

page_text: piston in the left hand cylinder being in equilibrium as both ends of its cylinder
are open to the vacuum side of the bucket the only pressure exerted by the water
in the pump barrel is on the back of the piston in the right hand cylinder The
result is that the piston in the right hand cylinder is driven over to the cover side
of that cylinder carrying with it the piston in the left hand cylinder thereby
reversing the slide valve of the steam cylinder.
The action which we have described as taking place upon the reversing piston
in the right hand cylinder takes place upon the reversing piston in the left hand
cylinder when the pump bucket makes its back stroke.
COMPLETE SPECIFICATION.
We, JOHN NICHOLAS FLOYD of Cornwall Cottage, Murdock Road, Handsworth
in the County of Stafford Mechanical Engineer, and GEORGE TANGYE of Cornwall
Works, Soho, in the County of Stafford, Manufacturer do hereby declare the nature
of our invention for "IMPROVEMENTS IN WORKING THE SLIDE VALVES OF STEAM
PUMPS and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
"
Our invention consists of the construction and arrangement of parts hereinafter
described for automatically working the slide valves of steam pumps by the action
of the water pressure in the pump barrel or pump cylinder.
We fix outside the pump barrel or pump cylinder or steam cylinder, two small
cylinders in each of which a piston works hereinafter called the reversing pistons.
The piston rods of these reversing pistons are situated on opposite sides of the
steam cylinder slide valve. The ends of each small cylinder are in communication
by means of ports or passages with the pump barrel. That port which is situated
at the closed end of each small cylinder we will call the back port and that situated
at the cover end of the cylinder we will call the front port.
When the bucket or piston of the pump barrel is making its stroke, say, from
left to right and the said bucket has so far advanced as to be between the front
'ports of the two small cylinders the position of the parts is as follows:-The two
ports of the right hand cylinder are in communication with the water pressure in
the pump barrel on the right hand side of the bucket and the two ports of the left
band cylinder are in communication with the vacuum in the pump barrel on the
opposite side of the pump bucket and the reversing pistons are at the cover ends
of their respective cylinders. The ports of the right hand small cylinder being thus
in communication with the water pressure, the said pressure acts on opposite sides

page_text: of the piston in that cylinder and the said piston is consequently in equilibrium;
and similarly the ports of the left hand small cylinder being in communication
with the vacuum or suction in the pump cylinder the piston in the said small
cylinder is preserved in equilibrium. The slide valve is consequently stationary.
As the pump bucket advances in the direction indicated, that is, from left to right,
it first covers the back port of the right hand small cylinder and afterwards
uncovers it and puts the vacuum or suction side of the bucket in communication
with the back end of the said cylinder. The water is thereby exhausted from the
said back end of the cylinder into the pump barrel on the vacuum side of the
bucket. The reversing piston in the left hand cylinder being in equilibrium, as
both ends of its cylinder are open to the vacuum side of the bucket, the only
pressure exerted by the water in the pump barrel is on the front of the piston in
the right hand cylinder. The result of this is that the piston in the right hand
cylinder is driven over to the back end of that cylinder and its piston rod moving
the slide valve of the steam cylinder reverses the said slide valve.
The action which we have described as taking place upon the reversing piston in
the right hand cylinder takes place upon the reversing piston in the left. hand
cylinder when the pump bucket makes its back stroke.
The accompanying Drawing represents in horizontal section, partly in plan,
a double acting steam pump with which is combined mechanism constructed
according to our invention for automatically working the steam cylinder slide
valve of the said pump.
a is the pump barrel or pump cylinder and b the steam cylinder in a line with
the said pump barrel; c is the pump bucket or piston and d is the steam piston
the said pistons c and d being connected together by the same piston rod e as usual.
The piston rode works in stuffing boxes f, f between the pump and steam
cylinders a, b; g. h are the two small cylinders situated at the side of the steam
cylinder 6 and at a short distance apart. Between the opposed ends of the two
small cylinders g, h is the steam chest i in which the steam cylinder slide valve j
travels, the opposite faces of the said slide valve j being provided with adjustable
projections k,l for the purpose herein after described. In the small cylinder g
a reversing piston m works and in the other small cylinder h a similar reversing
piston n works. The piston rods of the two pistons m, n are not connected
together but are situated on opposite sides of the slide valve j so that they can act
upon the adjustable projections k,l on the said slide valve for reversing it. The
piston rods of the two reversing pistons m, n work through the stuffing boxes
represented. The small cylinder g is in communication with the pump barrel a by
means of the two ports or passages p and p³, the port p opening into the front or
cover end of the cylinder g and the port p³ into the other or back end of the
cylinder g; and the small cylinder h is in communication with the pump barrel a
by means of the two ports or passages 9 and 9 the port 9 opening into the front
or cover end of the cylinder hand the port q' into the back end of the said
cylinder h.
In the drawing the parts are represented in the following positions The steam
cylinder piston d and the pump bucket c have reached nearly the end of their
stroke from left to right as indicated by the arrow and the slide valve j is about to
be reversed. The slide valve j being in the position represented and just before
the pump bucket c has reached the position represented, the two ports q, q³ of the
small cylinder h are in communication with the water pressure in the pump
barrel a on the right hand side of the bucket or piston c. At the same time the
two ports p, p' of the small cylinder g are in communication with the vacuum or
suction on the opposite side of the pump bucket o and the reversing pistons m
and n are situated at the front or cover ends of their respective cylinders. The
result of this arrangement is that the water pressure acting on opposite sides of the
reversing piston n maintains it in equilibrium and that both sides of the piston m
being in communication with the vacuum that piston is also maintained in
equilibrium and the slide valve is thereby preserved in its reversed position,

page_text: As soon as the pump bucket o in its motion in the direction indicated by the
arrow reaches and passes slightly beyond the position represented, it first covers
the port g and afterwards uncovers it and puts the vacuum or suction side of the
bucket in communication with the back end of the cylinder h. The water in the
said cylinder h is thereby exhausted from it into the pump barrel on the vacuum
side of the bucket and the front end of the cylinder h being in communication
with the water pressure in the pump barrel a through the port q the said water
acts upon the front of the piston n and drives it over to the back end of the said
cylinder h. In the motion of the piston n its piston rod acting on the projection 7
on the slide valve ; reverses the said slide valve.
On the pump bucket c making its reverse stroke, the port a becomes an exhaust
port and the port q temporarily a water pressure port, the result of which is that
the reversing piston n is returned to the position represented in the Drawing and
by the opening of the port q³ to the exhaust side of the bucket c, the two sides of
the piston n are in equilibrium until the return stroke of the bucket o in the
direction of the arrow as before described.
On the pump bucket approaching the end of its stroke in a direction contrary to
that indicated by the arrow the reversing piston m is driven over in the manpor
described with respect to the piston n and the slide valve is reversed and then
'occupies the position represented in the drawing.
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 of "Improvements in working the slidė valves of steam pumps
"
Automatically working the steam cylinder slide valves of double acting steam
pumps by the combination with the said steam pumps of the two small cylinders g, h
in communication by means of ports with the pump barrel or cylinder, the said
small cylinders g, h being furnished with reversing pistons the rods of which are
situated on opposite sides of the steam cylinder slide valve, the said slide valvo
being reversed on the pump bucket approaching the end of its stroke in either
direction by the said reversing pistons, the several parts acting substantially as
herein before described and illustrated in the accompanying Drawing.
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