Improvements applicable to Direct-acting Steam Pumps.
Year: 1898

page_text: Improvements applicable to Direct-acting Steam Pumps.
I, WILLIAM WEIR, of Holm Foundry, Cathcart, in the County of Renfrew,
North Britain, Engineer, do hereby declare the nature of this invention to be as
follows, that is to say:-
-
My said invention comprises an improved construction and combination of
parts of direct-acting steam pumps, rendering them safer and capable of being
driven at a greater speed when working at high pressures and is applicable to
bucket and plunger" types.
pumps of the double-acting and trunk-piston or
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In double-acting pumps when the steam piston area is considerably greater
than the water piston or bucket area, the ratio of the effective areas is so altered
by the rod attachment as to produce a dangerous difference in the pressure exerted
in the pump discharge between the up and down strokes, rendering the speed of
the water through the suction valves unequal on the up and down strokes. This
is more especially the case at high pressures when the rods are necessarily large
are fitted this effect is aggravated.
outside liners"
and when sleeves or
in area,
In carrying out my invention in double-acting pumps I make the diameter of the
rod at the part working through the stuffing box of the steam cylinder greater
than the diameter of the part working into the pump,--the difference between
the two diameters depending on the ratio of piston to bucket. When the end
of the rod is fitted with a sleeve I attach the valve gear to the sleeve which is
fixed to the bucket. When the bottom end of the rod is constructed in a separate
piece, attachment is made by screwing this piece into the top part. On account
of the larger diameter of the top part of the rod this construction or manner of
fastening may be carried out without introducing any disadvantages as the rod
may be withdrawn without taking off the steam piston.
When the pump piston or bucket is fitted with a trunk or plunger I arrange
the passage by which the water leaves the top or plunger side of the bucket into
the discharge with a contracted opening or adjustable valve. By this means
the water which is delivered into the plunger side of the bucket on the down
stroke is expelled on the up stroke through the contracted opening. The object
of this contracted opening or valve is to retard or limit the speed of the pump
during the suction stroke in order that the pump may not run faster than the
water can follow up and fill the chamber. The attainment of this permits the
return stroke to be made at a greater speed.
Dated this Seventh day of February 1898.
EDMUND HUNT,
Applicant's Agent.

page_text: Improvements applicable to Direct-acting Steam Pumps.
I, WILLIAM WEIR, of Holm Foundry, Cathcart, in the County of Renfrew,
North Britain, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, that is to say;-
My said invention comprises an improved construction and combination of
parts of direct-acting steam pumps, rendering them safer, and capable of being
driven at a greater speed when working at high pressures, and is applicable to
pumps of the double-acting and trunk-piston or bucket and plunger" types.
And in order that my said invention and the manner of performing the same
may be properly, understood, I hereunto append three sheets of explanatory
drawings to be hereinafter referred to in describing my improvements.
Figure, 1, on Sheet, 1, of the drawings is a sectional elevation of a double-acting
pump. Figures, 2, and 3, (Sheet, 2) are vertical and horizontal sections of a
"bucket and plunger" pump. Figure, 4, (Sheet, 3) is a side elevation (partly
in section) of another pump of the "bucket and plunger" type, and Figure, 5,
is a vertical section of a detail. In these drawings the same reference letters
and numerals are used to mark the same or like parts wherever they are repeated.
In a double-acting pump such as is shown in Figure, 1, of the drawings when
the steam piston area is considerably greater than that of the water piston or
bucket, the ratio of the effective areas is so altered by the rod attachment as to
produce a dangerous difference in the pressure exerted in the pump discharge
between the up and down strokes, rendering the speed of the water through the
valves unequal on the up and down strokes. This is more especially the case
with high pressures when the rods are necessarily large in area, and when sleeves
or outside liners" are fitted on the rods this effect is aggravated. By my.
invention such dangers and disadvantages are overcome; and in carrying it out
I make the diameter of the rod, A, at the part, A 1, working through the stuffing
box, B, of the steam cylinder, C, greater than the diameter of the part, A 2,
working into the pump, E, the difference between the two diameters depending
on the ratio of the steam piston, F, to the water piston, F 1. The parts, A1, A2,
composing the complete rod, A, may be made in one piece, but when the lower
part, A2, is made in a separate piece, as shown in Figure, 1, its top end, A 3, is
screwed to the upper part, A 1, the valve gear crosshead piece, G, being fixed to
the smaller part, A 2, by a pinching screw, G 1, or in any other convenient way.
When the smaller part, A 2, of the rod is fitted with a sleeve or outside liner"
(not shown) the valve gear crosshead piece, G, is attached to the sleeve, which
sleeve itself is attached to the piston.
When the pump or water piston, F 1, is fitted with a trunk or plunger, H, as
shown in Figure, 2, I arrange the passage or port, J, by which the water is expelled
from the top or plunger side of the piston, F1, into the discharge pipe, K, with a
contracted opening, J1, preferably formed by an adjustable valve, J2, worked
by a handled screwed spindle, J3, fitted in a bracket, J 4, attached to the pump
casing J5. On the down stroke of the pump the water, which has been drawn
into the pump during the up stroke through the suction valves (not shown) in
the seat, L, is forced through discharge valves (not shown) in two separate
seats, L1, L2, one half going to the discharge pipe, K, and the other half passing
into the cylinder at the top or plunger side of the piston, F 1. On the next up
stroke of the pump the water on the top side is expelled through the contracted
opening, J1, formed by the adjustable valve, J2, into the discharge pipe, K.

page_text: The object of this contracted opening is to retard or limit the speed of the pump
during the up or suction stroke, in order that the pump may not run faster than
the water can follow up and fill the pump chamber, E. This permits of the down
or return stroke being made at a greater rate of speed.
In another modification of my improvements shown in Figure, 4, the pump,
which is of the "bucket and plunger type," is provided with a single discharge
valve, M, and a set of suction valves, M 1. The passage, J, partly formed by a
pipe in this case, leads from the top side of the discharge valve, M, through a
partial non-return valve, N, to the top side of the piston, F 1, the valve having
a small hole or contracted opening, № 1. (Figure, 5) through it. On the down
stroke of the pump, part of the discharge water ascends the pipe or passage, J,
opening the valve, N, and passes freely into the space on the top side of the
piston, F 1. On the up stroke the valve, N, closes and the water on the top side
of the bucket is compelled to pass to the main discharge pipe (not shown) through
the contracted opening, N 1, thereby limiting the speed of the pump and allowing
time for the water to fill the pump chamber, E, below the piston, F 1, as in the
previous modification.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is;
-
1. In a direct double-acting steam pump, making the rod connecting the steam
and pump pistons with its steam part of greater sectional area than its pump
part, the attachment for the valve gear being on the pump part of the rod, sub-
stantially as and for the purposes hereinbefore described with reference to
Figure, 1, of the accompanying drawings.
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2. In a direct-acting steam pump of the "bucket and plunger or trunk-piston
type providing a contracted opening for restricting the delivery of the water from
the trunk side of the piston substantially as and for the purposes hereinbefore
described with reference to Figures, 2, and 3, of the accompanying drawings.
3. In a direct-acting steam pump of the "bucket and plunger" or trunk-piston
type, providing an adjustable opening for restricting the delivery of the water
from the trunk side of the piston substantially as and for the purposes hereinbefore
described with reference to Figures, 2, and 3, of the accompanying drawings.
4. In a direct-acting steam pump of the "bucket and plunger" or trunk-piston
type providing a restricted opening for the delivery of the water from the trunk
side of the piston, such opening being in a valve which lifts to freely admit the
water to the said side substantially as and for the purposes herein before described
with reference to Figures, 4, and 5, of the accompanying drawings.
Dated this Fourth day of November 1898.
EDMUND HUNT,
Applicant's Agent.