AN IMPROVEMENT IN STEAM PUMPS
Year: 1879

page_text: LETTERS PATENT to John Whitham Wilson, of Sunderland, in the County of
Durham, for the Invention of "AN IMPROVEMENT IN STEAM PUMPS."
PROVISIONAL SPECIFICATION left by the said John Whitham Wilson
at the Office of the Commissioners of Patents on the 23rd August 1879.
JOHN WHITHAM WILSON, of Sunderland, in the County of Durbam.
IMPROVEMENT IN STEAM PUMPS."
"AN
My Invention relates to an improvement in steam pumps, having for its object to
preveut any material increase of speed (to which most small steam pumps are subject
on missing water) and to enable even the smallest sized pump to be worked at a
very slow speed.
The improvement whereby the above mentioned objects are accomplished
without rendering the pump cumbersome, consists in applying a flywheel directly
upon the piston rod connecting the piston and plunger, or upon an extension of
said rod at the other side of the piston, the piston rod or extension having a screw
of rapid pitch cut upon it that works through a corresponding female screw or nut
in the hub of the flywheel which it operates as follows:-The flywheel is confined
between brackets or otherwise prevented from partaking in the rectilinear motion
of the piston rod, and the piston rod is prevented from rotating by keys received
in a longitudinal key way cut in it, so that at each stroke the screwthreaded
piston rod is forced through the nut of the flywheel to which it imparts rotary
motion in a plane perpendicular to the piston rod, this motion being reversed at
cach reversal of the motion of the piston rod. Thus at the end of each stroke the
flywheel must be stopped and its motion reversed before the return stroke can be
made, the flywheel thereby controlling the pump.
The power obtained through the motion of the flywheel at the end of the stroke
The slide valve is
enables the pump more efficiently to work its own valve.
worked from the piston rod by means of a tappet gear arrangement, a rocking
weight being employed to make the opening of the ports positive. The piston rod.

page_text: moves the weight slightly past its centre of gravity when it falls and completely
opens the valve and reverses the pump. The power of the flywheel is of great use
in lifting the weight as this is done within about 1 inch of the end of the stroke.
The weight is employed to do away with the necessity of forcing the piston against
the steam, and thereby requiring a much less flywheel, for from the beginning of
the opening of the port until full open the piston must naturally have traversed some
distance against the steam. By this arrangement the work of opening the valve is
done by the weight during the stroke (thereby making the weight a reservoir for
work), and without forcing the piston (by means of the flywheel) against the steam
working the valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Whitham Wilson in the Great Seal Patent Office on the 23rd
February 1880.
JOHN WHITHAM WILSON, of Sunderland, in the County of Durham.
PROVEMENT IN STEAM PUMPS."
"AN IM-
My Invention relates to an improvement in steam pumps, having for its object
to prevent any material increase of speed (to which most small steam pumps are
subject) on missing water, and to enable even the smallest sized pump to be worked
at a very slow speed.
The improvement whereby the above mentioned objects are accomplished
without rendering the pump cumbersome, consists in applying a flywheel directly
upon the piston rod connecting the piston and plunger, or upon an extension of
said rod at the other side of the piston, the piston rod or extension having a screw
of rapid pitch cut upon it that works through a corresponding female screw or
nut in the hub of the flywheel. The nut is preferably loose in the flywheel and
connected with it through the medium of springs, as hereafter described. The nut
and flywheel being prevented from partaking in the rectilinear motion of the
piston rod, and the piston rod prevented from rotating the screwthreaded piston
rod is at each stroke forced through the nut thereby imparting rotary motion to
the flywheel in a plane perpendicular to the piston rod, this motion being reversed
at each reversal of the motion of the piston rod. Thus at the end of each stroke
the flywheel must be stopped and its motion reversed before the return stroke can
be made, the flywheel thereby controlling the pump. The power obtained
through the motion of the flywheel at the end of the stroke enables the pump more
Figure 1 is an elevation, and Figure 2 a vertical section of a steam pump having
a flywheel applied and operated according to my Invention. A, A', are the steam
cylinder and piston, and B, B', the pump barrel and plunger. C is the piston rod,
and D, a screwthreaded extension thereof made separate from but together with a
crosshead E rigidly keyed to the piston rod C by a through key c. The screw D is
of very rapid pitch, varying with the diameter of the screw and with the diameter
and weight of the flywheel. The crosshead E works along a fixed guide F,
whereby the piston rod C and its screwed extension D are prevented from rotating.
G is a bush having a female screw or nut cut in it through which the screw Ď
passes. It has a flange g so confined by the frame of the pump that whilst free to
rotate it is incapable of participating in the longitudinal reciprocating motion of the
screw D. H is a radial arm or lever keyed upon the bush or nut G, and I is the
flywheel mounted to rotate loosely upon the boss of the arm H. This arm extends
to the rim of the flywheel I, and spiral springs K are applied to press against its
extremity at either side, the said springs being confined between brackets L bolted
to the flywheel, and kept in position by a rod M passing through them. This rod
is curved concentrically with the flywheel and passes freely through the end of the
arm H, the ends of the rod being fixed in the brackets L. These springs K act as
elastic buffers interposed between the flywheel I and the nut G of the screw D, by.
which the flywheel is operated, in order to lessen the violence of the shock caused
by the sudden stoppage and reversal of the flywheel each time the piston rod and
its screw arrive at the end of the stroke, which might otherwise damage the screw
or nut.
By the arrangement shown the energy of motion of the flywheel is
expended at the end of the stroke in compressing alternately the one spring or the
other, the recoil of which starts the wheel in the reverse direction.
N is a con-
necting rod jointed to the extremity of the crosshead for working the slide valve O

page_text: +
of the steam cylinder. Its lower end is provided with a longitudinal slot in which
plays a stud on the extremity of a lever arm P keyed on a rocking shaft Q mounted
in suitable bearings. The lever arm P is outside the valve chest, and its radius
is indicated by the dotted are in Figure 2. Another lever arm R is keyed on the
rock shaft Q within the exhaust passage, and its rounded end is received in a
cavity in the face of the slide valve O. The stud on the lever P is struck by
either end alternately of the slot in the connecting rod N, in which it is received,
thereby rocking the shaft Q and working the valve. The length of this slot in
the connecting rod N is equal to the length of the piston stroke, minus the length
of travel of the valve, whereby the steam port is kept full open during three-
fourths of the piston stroke.
'
$
The Drawings represent a vertical pump, but the same arrangement may be
applied to a horizontal pump, a fixed bracket or other suitable stop being placed at
the other side of the flywheel to retain it in place if necessary. It will also be
understood that instead of applying the flywheel upon an extension of the piston
rod, it may be applied between the steam cylinder and the pump plunger upon a
scrow threaded part of the piston rod which would in this case connect the steam.
piston and the plunger instead of the latter being continued of the same diameter
through the end of the cylinder to the piston as in the example shown. The
arrangement shown in the Drawings is however that which I prefer.
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the hercin-
before in part recited Letters Patent is :-
.
1st. The employment, in combination with the piston or plunger rod, of a steam
pump, of a flywheel caused by the to and fro motion of said rod to rotate alternately
in opposite directions in a plane perpendicular to the said rod, as and for the
purpose specified.
2nd. The combination with the piston or plunger rod of a steam pump, of a
flywheel, a nut in or connected to the flywheel and a screw of rapid pitch on or
connected to the piston rod and working through the nut, substantially as and for
the purpose shown and described.
In witness whereof, I, the said John Whitham Wilson, have hereunto set
my hand and seal, this Twentieth day of February, in the year of our
Lord One thousand eight hundred and eighty.
TATT
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UITGAN
WILSON. (S.)
TATTTTTT
LIHA NHOP