Improvements in Differential Pumps.FER
Year: 1887

page_text: Date of Application, 1st Sept., 1887
Complete Left, 29th May, 1888
Complete Accepted, 29th June, 1888
Improvements in Differential Pumps.
I, JAMES MILLER, of Adelaide in the Province of South Australia, Engineer, do
hereby declare the nature of my invention for "IMPROVEMENTS IN DIFFERENTIAL
PUMPS," to be as follows:-
My invention consists of a differential plunger pump, the plunger is made hollow
for the water to pass through it, one half of the working part of the plunger is larger
in diameter than the other working half to the extent that the annular sectional area
of the larger working portion shall be equal to or about equal to the total sectional
area of the smaller working end of the plunger inclusive of the area of the passage
way through it, the large and the small plungers are cast in one piece but may be
jointed together at the junction of the two. Each plunger works through an ordinary
packing gland into a plunger case. The large plunger instead of being cast or made
of such a thickness that its annular area would be equal to the total area of the small
plunger is made of only sufficient thickness to give the necessary strength and its
annular area is made up by lagging its interior with timber or other light
material.
The supply water is admitted through an ordinary suction valve to the rear or
suction end of the large plunger, and when the plunger is forced into its case the
water is forced through it and also through the interior of the small plunger upon
whose end is secured an ordinary delivery valve the water passing through the same
into the delivery pipe and when the small plunger in its turn is forced into its case it
at the same time forces an amount of water into the delivery pipe equal to its cubical
contents so that whichever way the plungers are moved about equal quantities of
water are delivered into the delivery main. The pump is fitted with only one suction

page_text: valve and with only one delivery valve. These serve both plungers and as soon as the
suction water enters the plunger case it is forced out in a free straight line course
through the pump into the delivery main without having to pass through any bends
or angles whatever. The pump is applicable to mining, irrigation, and to any circum-
stances where water has to be forced to some elevated position.

page_text: I JAMES MILLER of West Terrace in the City of Adelaide and Province of South
Australia, Engineer do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by the
following statement
My invention consists of a differential plunger pump. The plunger is made hollow
for the water to pass through it. One half of the working part of the plunger is larger
in diameter than the other working half to the extent that the annular sectional area of the
larger portion of the plunger shall be equal to or about equal to the total sectional area of
the smaller working end of the plunger including the area of the passage way through it.
The large and the small parts are cast in one piece but may le made separately jointed
together at the junction of the two. Each portion of the plunger works through an
ordinary packing gland into a plunger case. The large part of plunger instead of
being cast or made of such a thickness that its annular area would be equal to
the total area of the small part of plunger is made of only sufficient thickness to give
the necessary strength and its annular area is made up by lagging its interior with
timber or other light material.
The supply water is admitted through an ordinary suction valve to the rear or
suction end of the large part of plunger and when the plunger is forced into its case
the water is forced through it and also through the interior of the small part of plunger
upon whose end is secured an ordinary delivery valve the water passing through the
same into the delivery pipe and when the small part of plunger in its turn is forced
into its case it at the same time forces an amount of water into the delivery pipes equal
to its own cubical contents so that which ever way the plungers are moved about
equal quantities of water are delivered into the delivery main. The pump is fitted
with only one suction valve and with only one delivery valve. These serves both
plungers and as soon as the suction water enters the plunger case it is forced out in a
free straight line course through the pump into the delivery main without having to
pass through any bends or angles whatever.
The pump is applicable to mining, irrigation, and to any circumstances where water
has to be forced to some elevated position.

page_text: Figure 8 is a bar of iron to secure the valve cover to the valve.
Figures 9 and 10 are plan and section of the delivery valve at the discharge end of
the plunger.
The same letters in the drawings refer to the same parts in all the figures.
In figure 1 N is the bed plate to which the pump is secured B, B, is the plunger
case in which works the large end of the plunger A", A", through the packing
gland J, Ju
The greater portion of the length of the large end of plunger is recessed in the
inside and the recess is filled in with wood lagging as shown at P, P, the end of the
recess being of a dove-tailed form to properly secure the said lagging. At the end of
the plunger where the lagging is put in for the breadth of one of the lagging pieces
the metal collar is left square instead of being of a dovetailed form.
At this square part the whole of the lagging is introduced and slid round until the
whole of the recess is properly filled up with the lagging the last piece to be wedged
down hard and a hole may be drilled through the shell of the plunger and a counter
sunk screw put in through the end of the last piece to secure it. E shows a section
of the boss of a cross bar cast in the end of the plunger to which is secured the
driving rod D with a collar D on its end. E is a nut to screw the collar D
thoroughly tight into the boss of the cross bar E. A steel pin being fitted through
the nut and rod as shown to make it secure. F and F are cover and packing glands
through which the driving rod D" works, making it water tight, C is a doorway
to give access to the nut E and C¹¹ a cover for same.
The dotted lines H show the passage to the suction valve G is a foot cast upon the
plunger case to secure it to the bed plate N with screw bolts and two key strips and
key as shown. J and J" is the plunger packing gland. I and I" is a wrought iron
strap or hoop bored out and shrunk up on the inner end of the large part of plunger
from which a reciprocating motion may be obtained when the pump is at any time
worked as a direct acting steam pump.
a shows one of a pair of stripes cast upon the bed plate between which moves to
and fro, I" which is a projecting arm forged upon the aforesaid hoop. This is to
prevent any tendency the plunger may have to rotate in the packing gland. The
upper arm, with the hole I though it is where a motion may be obtained for the steam
valve of a steam cylinder. Otherwise the pump may be operated by horse wind, or
other suitable power.
If by steam power the bed plate N would require to be made longer in order that
that the steam cylinder could be fixed securely to it. A. A. show the small part of
plunger which works through the packing gland J and J and into the plunger
case M. M. G is a foot cast upon it for the purpose of fixing and securing it to the bed
plate with screw bolts and two key strips and keys as shown. M" is the discharge
opening into the delivery main. K is a brass valve seating bored out a little taper
and driven tight into the end of the plunger, which has a corresponding taper.
A pin or screw may be put through the valve and the plunger as a safeguard against
its getting loose.
K is the valve cover which is a disc of leather secured to the top side of the valve
by means of two set screws and a wrought iron bar.
The valve has an internal part cast hin it in which the set screws are secured as
shown.
A wrought iron plate is rivetted in each side of the leather forming the valve cover,
as shown the outside plate being large enough to cover the edge of the valve seat and
the inside plate small enough to go inside with considerable clearance. L is a
doorway to give access to the said valve. L' is the cover of same and L" is an air
vessel fixed to the back of the said cover with screw bolts.
Figure 2 is a ground plan of the pump. B, B, is the casing for the large part of
plunger AA" PP shews the wood lagging as previously explained. and Ju
is the packing gland. E is the cross bar cast in the end of the plunger for the attach-
ment of the driving rod D₁ which is secured by the said cross bar by means of the
collar D and nut E with a steel pin through the two as shown.
F and F are cover

page_text: and packing gland on the end of the plunger casing through which the rod D
works watertight. H is the passage to the suction valve. I shows the wrought iron
hoop shrunk upon the plunger end to get a motion for steam valve if required. a. a.
in dotted lines show two strips cast upon the bed plate between which travel the
lower arm of the hoop I. A. A. is the small part of plunger working through the
packing gland U" into the casing M. M. and M" is the discharge outlet. K is
the brass valve on the end of the plunger fitted with valve cover as explained. N is the
bed plate on which the pump is secured.
Figure 3 is an end sectional elevation of the pump through the line A, B. B is the
plunger case. G the foot cast upon same to secure it to the bed plate N. D is the
pump rod, E the nut to secure the same to the plunger with steel pin as shown. Cis
the cover of doorway giving access to nut and pin. H the passage leading to suction
valve. R is the suction valve chamber casting and R³ is the cover to give access to
the suction valve. R2 is the valve seating. b is a cross bar cast in same down
through which passes a flat bar with a cotter 11 at top to secure the valve cover
with an angle piece n and cotter 1 as shown, and pin to secure it. N is the bed
plate to which the pump is secured.
?"
Figure 5 shows an end view of the large part of plunger with cross bar E for
attachment of pump rod D.
Figure 6 is a plan view of suction valve, b. is crossbar in same through which
passes the flat rod r to secure the leather cover to the valve by means of the cotter
hole and cotter as seen in figure 3.
Figure 7 is a sectional view of the valve showing bridge and hole for tightening
bar for securing valve cover.
Figure 9 is a sectional view of delivery valve.
Figure 10 is a plan view of same. h is a thickened part in which to screw the two
set screws for securing the valve cover to the valve.
Figure 4 shows a method of placing the delivery valve at the junction of the
two portions of plunger instead of at the end of the plunger as seen in Figures 1
and 2. A" is a portion of the large portion of plunger and A is a portion of the
small plunger. S is the valve fixed in the end of the large plunger and S is the
cover of the same. S' shows that the leather disc of the valve cover is secured by
means of two screw bolts and a plate of wrought iron to the inside of the doorway
which gives access to the valve. This valve cover is similar to the one on the
delivery valve shewn in Figure 1. T is the cover to the doorway.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First The application of the method of constructing a differential hollow plunger
pump with one suction valve both parts of plunger being hollow with stop valve on
the delivery end of small part of plunger.
Second-The method of making both portions of plunger hollow for the free
passage of the delivery water.
Third-The fixing of the delivery valve on the delivery end on the small part of
hollow plunger.
Fourth-The method of fixing the delivery valve at the junction of the large with
the small portion of plunger.
Fifth-The construction of the large portion of plunger of only sufficient
thickness to give it the required strength, and packing the inside of the shell with
timber or other light material until the annular area of the large end of plunger about
equals the whole area of the small end of plunger inclusive of water way.
Sixth-The method of arranging and constructing a pump in such a way that the
water or other liquid operated on may be forced through and out of the pump into

page_text: the delivery main without the usual necessity of being force through bends and right
angles all substantially as described.
Seventh-A combination of the above as a whole or any part or parts thereof as
may be deemed expedient or desirable with each other or with known appliances.
Dated this Twenty third day of April One thousand eight hundred and eighty
Witness,
JAMES MILLER.
CHARLES N. COLLISON.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.