IMPROVEMENTS IN OR APPLICABLE TO STEAM PUMPS
Year: 1883

page_text: LETTERS PATENT to Frank Pearn, Sinclair Pearn and Thomas Addyman, of
West Gorton, Manchester, in the County of Lancaster, Engineers, for an
Invention of "IMPROVEMENTS IN OR APPLICABLE TO STEAM PUMPS"
PROVISIONAL SPECIFICATION left by the said Frank Pearn, Sinclair
Pearn, and Thomas Addyman at the Office of the Commissioners of Patents
on the 30th October 1883.
FRANK PEARN, SINCLAIR PEARN, and THOMAS ADDYMAN, of West Gorton,
Manchester, in the County of Lancaster, Engineers, "IMPROVEMENTS IN OB
APPLICABLE TO STEAM PUMPS,"
Firstly-Our invention is applicable to direct acting steam pumps for pumping
water, air or other fluids, and relates to means for actuating the slide valve of the
main steam cylinder, which regulates the admission and exhaustion of the steam
to and from the main steam cylinder, and this part of our invention consists in
giving the main steam valve a positive and uniform length of stroke partly from
a piston working in a separate small steam cylinder, and partly from the movements
of the piston rod of the main steam cylinder, the movements from these two sources
being combined to act together and assist each other.-According to our present
experience we prefer to carry out our invention by arranging the small steam
cylinder so that its piston rod will form part of, or be connected directly with the
spindle of the valve of the main steam cylinder, and we also connect the piston
rod by a connected rod with a small crank on a small crank shaft in suitable
bearings on the framing so that the reciprocating movement of the piston rod gives
rotary movement to the crank, and the crank thus determines and regulates the
movements of the main steam slide valve.
The slide valve for admitting and exhausting steam to and from the small steam
cylinder is worked from an excentric on the small crank shaft; On the small crank
shaft there is another small crank with which one end of a connecting rod is
jointed the other end of which is also jointed to one end of a lever on any suitable
fulcrum, the other end of which lever is connected by a rod with the main steam

page_text: piston and pump rod, the leverage being proportioned so that the full stroke of the
main piston rod will be equal to the throw of the crank upon the small crank shaft
with which it is connected.
"
The two small cranks are so arranged in relation to each other that they will
alternately assist each other over the "dead centres," and there is or may be
play" in the movement of the levers actuated from the main piston rod to permit
if desired, of variations to some extent in the stroke of the main steam piston and
pumps.
The main slide valve in the above described arrangement is or may in some
cases he worked from the crank shaft for the small piston and cylinder by an
excentric and rod.
We also connect with the piston rod of the small steam cylinder another small
cylinder which is filled with oil or other liquid which has to be moved by the
piston of this small cylinder at each stroke through a small passage from one end
of the cylinder to the other, this small cylinder thus acting as a "cataract'
cylinder" to prevent the piston of the small steam cylinder from moving too
quickly.
"
or
Secondly. Our invention relates to arrangements applicable to direct acting
steam pumps, which may be used alone or in combination with the improvements
forming the first part of our invention, and the object of this part of our invention
is to start each stroke of the steam piston and pumps slowly and "cushion"
cause each stroke or movement to terminate slowly and without shock and give
more time for the pump valves to act, and our invention consists in arranging the
main steam passages from the steam ports of the valve, so that each will terminate
some distance short of the ends of the cylinder, and in forming an additional
steam passage of small area from each main steam passage to the ends of the
steam cylinder.
"
The piston when near the end of its stroke will cover and close the opening into
the cylinder from the main steam passage at that end, and then the steam enclosed
between the piston and the end of the cylinder will act as a " cushion to retard
and stop the movement of the piston, as the small passage will only allow the
imprisoned steam to escape slowly and when the main slide valve suddenly moves
over, the steam will have to pass into the cylinder through the said small passage
and this will cause the piston to work slowly until it has moved a distance sufficient
to uncover the opening to the main steam passage when it will obtain its full
supple of steam.
In some cases we use a valve in each of the small steam passages arranged to
close each passage more or less against steam from the cylinder but allow steam
to pass slowly to the cylinder when the main slide valve opens.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Pearn, Sinclair Pearn, and Thomas Addyman 'in the Patent
Office on the 23rd April 1884.
FRANK PEARN, SINCLAIR PEARN and THOMAS ADDYMAN of West Gorton,
Manchester, in the County of Lancaster,. Engineers. "IMPROVEMENTS IN OR
APPLICABLE TO STEAM PUMPS,"
Firstly. Our invention is applicable to direct acting steam pumps for pumping
water air, or other fluids and relates to means for actuating the slide valve of the
main steam cylinder, which regulates the admission and exhaustion of the steam
to and from the main steam cylinder, and this part of our invention consists in
giving the main steam valve a positive and uniform length of stroke partly from
a piston working in a separate small steam cylinder and partly from the movements
of the piston rod of the main steam cylinder, the movements from these two sources
being combined to act together and assist each other.
:
According to our present experience we prefer to carry out our invention by
arranging the small steam cylinder so that its piston rod will form part of, or be
connected directly with the spindle of the valve of the main steam cylinder and
we also connect the piston rod by a connecting rod with a small crank on a small
crank shaft in suitable bearings on the framing so that the reciprocating movement
of the piston rod gives rotary movement to the crank and the crank thus
determines and regulates the movements of the main steam slide valve.
The slide valve for admitting and exhausting steam to and from the small steam
cylinder is worked from an excentric on the sinall crank shaft.
On the small crank shaft there is another small crank with which one end of a
connecting rod is jointed the other end of which is also jointed to one end of a
lever on any suitable fulcrum the other end of which lever is connected by a rod
with the main steam piston and pump rod, the leverage being proportioned so that
the full stroke of the main piston rod will be equal to the throw of the crank upon
the small crank shaft with which it is connected.
a
The two small cranks are so arranged in relation to each other that they will
alternately assist each other over the "dead centres," and there is or may be
play" in the movement of the levers actuated from the main piston rod to permit
if desired, of variations to some extent in the stroke of the main steam piston and
pumps.
The main slide valve in the above described arrangement is or may in some cases
be worked from the crank shaft for the small piston and cylinder by an excentric
and rod.
We also connect with the piston rod of the small steam cylinder another small
cylinder which is filled with oil or other liquid which has to be moved by the
piston of this small cylinder at each stroke through a small passage from one end
of the cylinder to the other, this small cylinder thus acting as a "cataract" cylinder"
to prevent the piston of the small steam cylinder from moving too quickly.
Secondly. Our invention relates to arrangements applicable to direct acting
steam pumps, which may be used alone or in combination with the improvements
forming the first part of our invention, and the object of this part of our invention
is to start each stroke of the steam piston and pumps slowly, and "cushion" or
cause each stroke or movement to terminate slowly and without shock and give
more time for the pumps valves to act, and our invention consists in arranging the
main steam passages from the steam ports of the valve so that each will terminate

page_text: some distance short of the ends of the cylinder and in forming an additional steam
passage of small area from each main steam passage to the ends of the steam
cylinder.
The piston when near the end of its stroke will cover and close the opening
into the cylinder from the main steam passage at that end, and then the steam
enclosed between the piston and the end of the cylinder will act as a “cushion ” to
retard and stop, the movement of the piston, as the small passage will only allow
the imprisoned steam to escape slowly and when the main slide valve suddenly
moves over, the steam will have to pass into the cylinder through the said small
passage and this will cause the piston to work slowly until it has moved a distance
sufficient to uncover the opening to the main steam passage when it will obtain its
full supply of steam.
In some cases we use a valve in each of the small steam passages arranged to
close each passage more or less against steam from the cylinder but allow steam to
pass slowly to the cylinder when the main slide valve opens.
Fig 1 is a partial side elevation with the main steam cylinder and its valve and
chest shown in section and fig 2 is a plan of the same but with the small steam and
cataract cylinders shown in section.
Figs 3, 4 and 5 are detached views illustrating the second part of our invention.
a is the main steam cylinder or one of the main steam cylinders of a direct
acting steam pump; b the main steam piston, 61 its rod; o¹ the pump piston rod,
c the pump. & is the valve for the main steam cylinder; d' is the valve rod,
connected with or forming part of the rod d³ for the small steam piston, working in
the small cylinder c.
The piston rods and d pass through glands, as shown, to another small
cylinder f lined with brass or other metal, and fitted with a piston, The piston
Tod d' is continued and has a fork attached to its end, which fork works on
suitable slides on the framing and this fork is jointed with one end of a connecting
rod d' the other end of which is attached to a crank pin, or crank g formed in a
shaft.g' having bearings on the framing.
One end of this crank shaft g' has an excentric g³ secured upon it which by a
connecting rod g³ jointed to it and to the spindle g' works the slide valve e¹ for the
small steam cylinder e. On the other end of the crank shaft g' there is a crank g³
set at right angles to that g connected to the piston rod d for the small steam
cylinder e, and to this crank g one end of a rod h is jointed, the other end of
which passes through a swivel block h¹ carried in arms hª from a rocking shaft h³
in suitable bearings on the, framing.
The end of the connecting rod h passing through the swivel block h' is screwed
for screw nuts to adjust the length of the rod.
On one end of the shaft h³ an arm * is secured, the end of which is jointed with
a rod h³ connecting it with an arm c² descending from a slide block c³ forming a
part connected with the coupling which unites the piston rods b¹ and c¹ of the main
steam cylinder and pump.
The arms h³ and h* on the rocking shaft h³ are proportioned to the length of the
stroke of the main steam cylinder, and the radius of the small crank 9 to be
actuated.
The small cataract cylinder is filled with oil or other fluid, and a small passage
is formed between one end of the cylinder and the other, so that as the piston
moves, the liquid in front of it at one end of the cylinder, will be transferred
through the said small passage to the other end of the cylinder.
"
A plug on the end of a screw is arranged in about the middle of the small
passage and passes through a packing gland, and by a handle f¹ on the outer end
the plug can be screwed in or out to reduce more or less the area of the passage
at that point and thus the resistance to the movement of the piston as required.
There is a slotted arm he mounted on the rocking shaft hand in the slit a slide
block is fitted actuated by a screw and handle h' (shown only in fig 1).

page_text: To this slide block one end of a rod i is jointed the other end of which is jointed
to a pin fixed in an arm i¹ secured on a shaft it having bearings in a bracket
secured to the framing.
The other end of the shaft i has also an arm 23 secured upon it which is
connected by a rod i with a valve spindle d passing through a suitable stuffing
box, which spindlo works a cut off valve de superimposed on the main slide valve d
which can be adjusted by the screw h² (fig 1) to cut off the supply of steam to the
main steam cylinder at any part of the stroke.
The improvements forming the second part of our invention, may be used alone
or in combination with those hereinbefore described.
In fig 1 the main steam passage a¹ terminates short of the ends of the cylinder,
at a and is of the rectangular form as shown at a fig '3, but there is also a
passage a³ of small area continued from the main steam passage a² to the end of
the cylinder, at each end, the opening from which into the cylinder is shown
by a³ in fig 3.
It will be seen that when the steam piston 6 covers the opening into the
cylinder at a² all the exhaust steam then remaining in that end is imprisioned, and
can only escape slowly through the small passage a³ which when desired may have
a valve or valves a' arranged in any convenient manner fitted in it as shown in
figs 4 and 5 to close against steam passing out but open to allow it to pass in to
the cylinder and this valve a' may fit more or less close as required. In fig 4 the
valve is shown in a horizontal position and kept against its seat by a spring; in
fig 5. the valve is supposed to be in a vertical position, and closes by its own
gravity.
When the piston b has arrived at the full length of its stroke, and the steam is
admitted by the main slide valve d to make the return stroke it can only pass
slowly through the small passage a³ until the piston has moved sufficiently to
uncover the opening a³ of the main steam passage consequently the piston is
brought slowly to rest and slowly started again into motion without shock also
giving time for the valves of the pump to close and open slowly and with less wear
and tear.
We have now particularly described the nature of our said invention and the
mode of carrying the same into effect and claim as our invention.
1. The combination of a small steam cylinder, cataract cylinders and connections
with the piston rod of the main steam cylinder, for working the main steam valvo
or valves of direct acting pumps, substantially as hereinbefore described and
illustrated by the drawings.
2. The arrangement and construction of main steam cylinders of direct acting
steam pumps, with there steam passages, so as to cause the piston to be brought
slowly to rest at the ending of each stroke and started slowly into motion at the
beginning of each stroke, substantially as hereinbefore described and illustrated by
the drawings.
3. The combination and arrangement of steam pumps substantially as hereinbefore
described and illustrated by the drawings.
In Witness whereof we the said Frank Pearn, Sinclair Pearn and Thomas Addyman
(or one of us) have hereunto set our hands and seals this twenty second day of
April in the year of our Lord One thousand eight hundred and eighty four.