AN IMPROVED CONSTRUCTION* OF PUMP FOR RAISING AND FORCING LIQUIDS, ALSO APPLICABLE FOR EXHAUSTING AND BLOWING OR COMPRESSING AIR OR OTHER ELASTIC FLUIDS."
Year: 1881

page_text: LETTERS PATENT to Donald MoLachlan, of Glasgow, in the County of
Lanark, North Britain, for an Invention of "AN IMPROVED CONSTRUCTION*
OF PUMP FOR RAISING AND FORCING LIQUIDS, ALSO APPLICABLE FOR
EXHAUSTING AND BLOWING OR COMPRESSING AIR OR OTHER ELASTIC
FLUIDS."
PROVISIONAL SPECIFICATION left by the said Donald McLachlan at the
Office of the Commissioners of Patents on the 5th March 1881.
DONALD MCLACHLAN, of Glasgow, in the County of Lanark, North Britain.
"AN IMPROVED CONSTRUCTION OF PUMP FOR RAISING AND FORCING LIQUIDS,
ALSO APPLICABLE FOR EXHAUSTING AND BLOWING OR COMPRESSING AIR OR
OTHER ELASTIC FLUIDS."
This Invention relates to an improved construction of pump for raising or lifting.
water and other liquids by suction, and for forcing and delivering such liquids, and
in a modified form also adapted for exhausting and blowing or compressing air or
other clastic fluids. The improved pump, which differs mainly from ordinary
pumps in having no solid working plunger or ram, is extremely simple in
construction, and is designed to reduce friction of moving parts and thereby
economise power.
In a modification of the improved pump adapted for raising water or other
liquid by suction the pump barrel is cast or formed of double or inner and outer
concentric tubes near the upper end, with an annular space or channel between
them, which join and become a single tube or suction pipe at the lower end, the
inner tube being of the same diameter throughout and terminating within a short
distance (according to the stroke of the pump) of the upper end or open mouth of
the outer barrel. The annular channel between the tubes is partially filled with
mercury, and the depth of the channel is made thirty inches or more, so that a
column of mercury within it when the pump is at work may balance the ordinary
atmospheric pressure. A short metallic open tube, which serves the purpose or is
used instead of a plunger, is fitted loosely within the outer barrel to enter the
annular space or channel and dip in its lowest position to nearly the bottom with
sufficient free space on each side for the displacement of the mercury, the length of
this tube being a little more than the depth of the annular channel. The upper
end of this tubular plunger is connected to an ordinary pump rod worked by a
crank or other motive power and by which this plunger is reciprocated.
A clack, lifting valve, or other suitable form of valve, is fitted over a seat or
'

page_text: grating on the upper end of this tubular plunger, and a similar valve is also fitted
at the top of the inner tube. During the upward stroke of the reciprocation of
the tubular plunger the water ascending in the pipe lifts the lower valve and fills
the space within the tubular piston above. In the descent of the piston or plunger
this water is discharged through the upper valve into the outer barrel or well
above and escapes through a spout formed at the side as usual. Both valves are
always covered with water, and the upper part of the annular space between the
outer and inner tubes forming the barrel is also filled with water. When the
plunger rises the mercury and water at the outer side of the plunger which is open
to the atmosphere are forced down by the atmospheric pressure and there is a
corresponding rise of mercury at the inner side. On the return stroke the
downward pressure on the inner side causes a rise of the mercury at the outer side,
but the weight or pressure of the column of mercury being always equal to the
atmospheric pressure the mercury cannot be forced out of its annular channel, but
acts as a lubricant for the reciprocating plunger tube, which thus works with a
minimum of friction.
When the pump is constructed to act as a force pump a cover is fitted over the
outer barrel, in which a stuffing box is. fitted for the pump rod to pass through,
and the annular channel is made of a depth to contain a column of mercury capable
of balancing or sustaining a pressure equal to that due to the height to which the
water is to be forced.
In constructing the improved pumping apparatus to adapt it for exhausting and
-blowing or compressing air or other elastic fluids the arrangements last described
of an inner and an outer covered barrel or tube and a tubular piston working into
a liquid such as mercury within the annular channel formed by the tubes are still
retained, but the liquid used to balance the atmospheric pressure within the
channel is preferably water, or a mixture or mixtures of water and other liquids,
such as glycerine and spirit, which are not liable to evaporate or freeze readily.
The lifting or moving valves are also made light and of a material suitable for the
various circumstances, as in ordinary air exhausting or blowing engines or
apparatus.
In a modified form of the improved pump adapted for the suction and forcing of
liquids and of elastic fluids, and which is designed to avoid the use of a stuffing
box, and thus still further reduce friction, the reciprocating tubular piston is made
double, that is, with an outer tube concentric with the valve tube and connected to
be in one piece with it by an upper annular end or fluid-tight cover, and the outer
piston tube also dips into a channel filled with mercury or other heavy liquid
formed at the lower end of an outer close covered cylinder which forms the discharge
well of the pump.
When the pump is at work the water rises through the inner or central suction
tube through the lower valve into the inner tubular piston and through the valve
in its upper end into this close discharge well. A free annular space, open to the
atmosphere, is left between the inner and outer channels of mercury or pressure
bearing liquid, and the connection between the actuating crank of the pump and
the reciprocating hollow piston is formed by fitting long connecting or guide rods
to the upper end of the piston passing through this free space and connected to a
crosshead beneath surrounding or clearing the suction pipe, and this crosshead is
then connected by double rods outside the well carried up to the crank or actuating
shaft.
For the purpose of maintaining an uniform pressure of the water delivered by
the improved pump, two or more pumps may be worked together from one crank
shaft, and the water from both discharged into a common receiver fitted with a
weighted diaphragm or with a sliding weighted piston which would yield to an
excessive pressure of water discharged by the pumps at each lift and by falling
would maintain the pressure during the return stroke of the pump.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Donald McLachlan in the Great Seal Patent Office on the 2nd
September 1881.
DONALD MCLACHLAN, of Glasgow, in the County of Lanark, North Britain.
"AN IMPROVED CONSTRUCTION OF PUMP FOR RAISING AND FORCING LIQUIDS,
ALSO APPLICABLE FOR EXHAUSTING AND BLOWING OR COMPRESSING AIR OR
OTHER ELASTIC FLUIDS."
My said Invention relates to an improved construction of pump for raising or
lifting water and other liquids by suction, and for forcing and delivering such
liquids, and in a modified form also adapted for exhausting and blowing or
compressing air or other elastic fluids. The improved pump which differs' mainly
from ordinary pumps in having no solid working plunger or ram, is extremely
simple in construction, and is designed to reduce friction of moving parts and
thereby economise power.
And in order that my said Invention, and the manner of performing the same
may be properly understood, I have hereunto appended for that purpose a Sheet of
explanatory Drawings to be hereinafter referred to, and representing modifications
of my improved pump. In these Drawings the same reference letters are used to
mark the same or like parts where repeated.
Figure 1 is a vertical section of a modification of my improved pump as fitted
for use on board ship, or as a simple suction or lift pump, and Figure 2 is a side
elevation of the same; Figure 3 is a vertical section of a modified construction
adapted to act as a force pump; and Figure 4 is a vertical section of part of a
pump barrel, sliowing a modified arrangement of the stuffing box or packing
ring.
Referring to Figures 1 and 2 of the Drawings the improved pump is shown
fitted through the deck of a ship to draw water from the hold, and is provided
with the usual actuating cranks mounted on the "fife rail" E, or supporting
framework over the deck E¹. The pump barrels, which are of novel construction,
are each formed of two tubes A, A¹, the one A fitted concentrically within the
other A¹ with an annular space a between them, and flanged and bolted at their
lower ends, as shown particularly in Figure 1; or the barrels may be similarly
formed of concentric tubes cast or welded together and joined at their lower ends
to form a single tube or suction pipe. The inner tube A. is of the same diameter
throughout, and terminates within a short distance (according to the stroke of the
pump) of the upper end, or open mouth, or discharge well A² of the outer barrel A'.
The annular channel a between the tubes A, A¹, is partially filled with mercury,
and the depth of the channel containing the mercury is made thirty inches or
more, so that a column of mercury within it when the pump is at work may
balance the ordinary atmospheric pressure. A short metallic open tube B which
serves the purpose or is used instead of a plunger, is fitted loosely within each
outer barrel A¹, between it and the inner tube A to enter the annular space or
channel a and dip in its lowest position to nearly the bottom with sufficient free.
space on each side for the displacement of the mercury, the length of this tube B
being a little more than the depth of the annular channel a. The upper ends of the
tubular plungers B are connected by guiding crossheads C, and ordinary pump.
rods or connecting rods C attached to cranks d on a crank shaft D carried in
bearing blocks D₁ bolted to the fife rail or framing E, and actuated by hand
cranks D² or by other motive power to reciprocate the plunger B and work the
pump. A clack lifting valve or other suitable form of valve b is fitted over a seat
or grating on the upper end of each tubular plunger B, and a similar valve ƒ iş

page_text: also fitted either at the bottom end of each inner tube A, or as is preferred on seats
formed by the upper ends of a "breeches" pipe F connected above by short
coupling tubes F to the pump barrel, and attached below to the main suction
pipe F. The valves f are formed with upper stems fitting in tubes f' which are
fixed within the coupling tubes F1 and serve as guides for the valves f, short
branches F³, with blind flanges being provided for convenience of access for repair
or cleaning.
The action of the pump is as follows:-During the upward stroke of the
reciprocation of the tubular plunger B the water drawn up or ascending in the
pipes F, F1, F2, lifts the lower valve f and fills the space within the tubular
piston B above. In the descent of the piston or plunger B this water is discharged
through the upper valve b into the outer barrel A¹ or well A² above, and escapes-
through a spout As formed at the side as usual. Both valves b, f, are always
covered with water, and the upper part of the annular space a between the outer
and inner tubes A¹, A, forming each barrel is also filled with water over the
mercury. When the plunger B rises the mercury and water within the space a at
the outer side of the plunger, which is open to the atmosphere, are forced down by
the atmospheric pressure, and there is a corresponding rise of mercury at the inner
side between the plunger B and the inner barrel tube A. On the return stroke
the mercury at the outer side of the plunger B balances that on the inner side, as
shown particularly in Figure 1.
The weight or pressure of the column of mercury being always equal to the
atmospheric pressure, the mercury cannot be forced out of its annular channel a,
but acts as a lubricant for the reciprocating plunger tube B which thus works
with a minimum of friction.
When the pump is constructed to act as a force pump a cover may be fitted
over the outer barrel, in which a stuffing box may be provided for the pump rod
to pass through, and the annular channel would then be made of a depth to
contain a column of mercury capable of balancing or sustaining a pressure equal to
that due to the height to which the water is to be forced.
I prefer however to construct the improved force pump, as shown in Figure 3, or
as in Figure 4, in which the arrangement of the pump barrel A, A¹, is very similar
to that shown in Figures 1 and 2; but a close cover B₁ is fixed over the tubular
plunger B, and a stuffing box formed by a packing ring a¹ of rubber, leather, or
other similar material is provided, and is either fixed to the plunger tube B, as
shown in Figure 3, or to the outer barrel A', as indicated in Figure 4, the packing
ring a being secured to a flange formed on the plunger B or pump barrel A³, and
in the latter case the ring being retained by a flange on an extension of the
barrel A, which may also form a guide for the tubular plunger B. By this
arrangement of stuffing box or packing ring a¹ a much shorter length of barrel A, A',
and annular dip channel a may be used than would be necessary when the chaunel
is open, and when the column of mercury in the channel a should be such as to
balance the pressure due to the height to which the water is to be forced.
The outlet for the water is formed by a branch pipe G attached to any convenient
part of the main pipe F¹ below the pump barrel, and which is fitted with a disc
flap valve g above the lower valve f.
The improved pump either when used for lifting or forcing water, or for blowing
or compressing air may be worked by any ordinary motive-power engine instead
of by hand.
For the purpose of maintaining a uniform pressure of the water delivered by the
improved pump two or more pumps can be worked together from one crank shaft,
and the water from both discharged into a common air receiver.
In constructing the improved pumping apparatus to adapt it for exhausting and
blowing, or compressing air or other elastic fluids, the arrangement of an inner and
an outer barrel or tube, and a tubular piston working into a liquid such as mercury
within the annular channel formed by the tubes is still retained, but the liquid
used to balance the atmospheric pressure within the channel may be water, or a

page_text: mixture or mixtures of water and other liquids, such as glycerine and spirits,
which are not liable to evaporate or freeze readily. The lifting or moving valves
are also made light, and of a material suitable for the various circumstances, as in
ordinary air exhausting or blowing engines or apparatus.
Having thus particularly described the nature of my said Invention, and the
manner of performing the same, I have to state that I do not restrict myself to the
precise details herein described or delineated, but what I believe to be novel and
original, and therefore claim as the Invention secured to me by the hereinbefore in
part recited Letters Patent is,-
First. The construction and combination of the parts of pumps for raising or
forcing and delivering water or other liquids, or for exhausting and blowing or
compressing air or other elastic fluids, substantially as herein described in reference
to the accompanying Drawings.
Second. In pumps for raising or forcing and delivering liquids, or exhausting and
blowing air or other fluid, the arrangement and construction of the pump barrel or
barrels, with an inner and outer tube forming an annular channel in which a
tubular plunger works in a column of mercury or other liquid balancing the
atmospheric pressure, or the pressure due to the height to which the water has to
be forced or raised, substantially as herein described in reference to the accom-
panying Drawings.
In witness whereof, I, the said Donald McLachlan, have hereunto set my
hand and seal, this Thirty first day of August, in the year of our Lord
One thousand eight hundred and eighty-one.
5 Witness,
WALLACE FAIRWEATHER, C.E.,
Of W. R. M. Thomson & Co.,
96, Buchanan Street,
Glasgow.
D. MCLACHLAN. (L.S.)