IMPROVEMENTS ON DUPLEX CRANK PISTON PUMPS
Year: 1885

page_text: I, JOSIAH Dow, of Lowell in the county of Middlesex and State of Massachusetts,
United States of America, Manufacturer, do hereby declare the nature of my
invention for IMPROVEMENTS ON DUPLEX CRANK PISTON PUMPS, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to improvements in duplex-crank piston pumps, particularly
well adapted for pumping liquids, and in this capacity to be used either as a
suction or force pump, although the invention is equally well adapted for use as an
air pump or blower for force or exhaust purposes as well as a water-motor if so
desired.
The invention is carried out as follows, references being had to the accompanying
drawings where Fig. 1 represents a side elevation of my improved pump; Fig 2
represents an end view thereof as seen from X in Fig. 1; Fig 3 represents a central
longitudinal section on the line A-B shown in Fig 2; Fig. 4 represents a cross
section on the line C-D shown in Fig 3; Fig 5 represents a cross-section on the
line E-F also shown in Fig 3, and Fig 6 represents a top view of the cylindrical
valves. Fig 7 represents a side view of one of the piston cylinders; and Fig 8
represents a cross section on the line G-H shown in Fig 7.
Similar letters refer to similar parts wherever they occur on the different parts.
of the drawings.
a a¹ is the shell cast in one piece, the portion a constituting the pump cylinder,
and the portion a¹ is the cylindrical valve chamber; a" is the base, cast in one,
piece with the aforesaid shell, it being a continuation of the cylindrical valve
chamber a' in case the latter is arranged below the pump cylinder a as shown in
the drawings, but I do not wish to confine myself to this precise arrangement, as
the valve chamber a¹ may be located above or on one side of the pump cylinder a
if so desired, although I prefer to arrange and locate the respective valve and pump
cylinders in the manner as shown.
Within the shell a a¹ is cast a division wall a³ extending from the top of the
pump cylinder a to the bottom of the valve-cylinder a', in a plane parallel to the
ends of said shell as shown in Fig 3, such division wall having a cylindrical cut
away portion a concentric with the pump cylinder a as shown in said Fig 3 to
permit a communication between the hollow cylinders of the duplex pistons as will
hereinafter be more fully described,

page_text: b and c represent the heads, secured, air and water tight, to the open ends of
the shell a a¹ by means of suitable bolts, nuts or screws as shown in the drawings.
The head c is provided with an opening c¹ leading to the central part of pump
cylinder a and is in open communication with the suction pipe d, the upper flange
of which is secured, air and water tight, to the outer end of head c, by means of
suitable bolts, nuts or screws as shown in Fig 3. e is the pump shaft located in
one end in a bearing 6¹ cast in one piece with the head band provided there with a
packing gland 6", made in the shape of an annular ring, or in two semi-circular
halves, as may be desired, said gland being kept in its proper place in said bearing
by means of a suitablé cap b³ and cap-screws as is usual on pillow-blocks or shaft
bearings.
64 is a suitable packing at the inner end of gland 611 as shown in Fig 3 so as to
make a perfectly tight joint between the shaft c and that part of the head 6 where
it projects through. In its other end, the shaft e is supported in a bearing d¹, cast
in one piece on the outside of suction pipe d, and provided there with a gland d",
cap d and packing d' in a similar manner às described relative to the bearing b¹.
I wish to state however that I do not confine myself to any particular bearings for
said shaft e, as I may if so desired use the ordinary stuffing boxes, such as used on
piston rods, of steam engines without departing from the essence of my invention.
The shaft e is set in a rotary motion, in its bearings by means of belt or other
power applied to a suitable pulley to 'said shaft, or in any other well known
manner.
To the shaft e is secured firmly the hollow cylinder f by means of its central
hub and curved and screw propeller shaped suction or guiding wings f", fil
shown in Fig 4; the object of said curved and screw propeller shaped wings f", "
is to aid in creating a vacuum in the interior of said cylinder f when it is rotated
and thus facilitate the liquid passing out through the side opening f³ (on the
periphery of cylinder f) and into the pump cylinder a; I prefer to make the outer
end of the guiding wings f" with a propeller shaped edge f10, to facilitate the
passage of Huids to the interior of the pump from supply pipe as represented in
Figs. 7 and 8.
In one piece with cylinder f is cast the piston f' which is located in front of
opening f³, and extending outwards and sideways sufficiently to fill the space
between the exterior of cylinder f and interior of pump cylinder a as shown in
Fig. 4.
75, f³ are side ribs connecting the piston f* with the cylinder ƒ so as to impart
the necessary strength to the piston.
11
By means of the curved and screw propeller shaped wings f"f" the cylinder f
is divided in two compartments f and f', the former communicating with the side
opening, and the latter passing entirely through from end to end of said cylinder
so as to establish a communication from the suction pipe d to the second cylinder g
secured to shaft e behind the first named cylinder f. f is a packing made of
metal or wood and placed in a groove on the sides and end of piston f' so as to
effect a tight joint between the said piston and the plane and curved parts of
cylinder a; f, f° are segmental packing rings located in corresponding recesses'
on the outer side edges of cylinder f so as to effect a tight joint between the ends
of cylinder f and corresponding interior walls of pump cylinder a; these packing
rings may be made of wood or metal.
On the shaft e in a line with the cylinder f, is secured the secondary cylinder g
having central hub g¹, curved and screw propeller shaped guide wings g₁ g, side
opening g³, piston 9', piston ribs go, go, compartment 98, packing 98 and segmental
packing rings g, 9º, like those described forming part of cylinder f.
es
The cylinders and g are so secured to each other and to their common shaft
as to cause their pistons f' and g* to project outwards in diametrically opposite
directions, and so that the compartment f³ in cylinder f stands in direct communi-
cation with the compartment 9 in cylinder g as shown in Fig 3. i is the valve
cylinder shaft, which shaft is located in bearings i¹³, cast in one piece respectively
し

page_text: with the heads.b and c and provided with glands 1, caps and packings in a
similar manner as the bearings for the pump shaft 6.
The shafts e and i are geared together by the respective gears kand I, the former
secured to shaft e, and the latter to shaft i, both of said gears being of equal-size
and having equal number of teeth as shown in Figs. 2 and 3, so that the shaft i
shall be turned around its axis exactly one revolution for every revolution of
shaft e.
Below the cylinder f is secured on shaft i the valve cylinder m, the outside.
diameter of which is made equal to that of the cylinder f, and as said cylinders
are rotated in opposite directions they are made to bear against each other, that is
just to touch each other without causing any frictional resistance, as shown in
Figs. 3, 4 and 5. m³ is the central hub of valve cylinder m, and m¹¹, m¹¹ are the
skeleton arms uniting the said hub with the valve-cylinder m, so as to make it as
light as possible consistent with the strength necessary. m³ is a cut-away portion
on one side of the valve-cylinder m to permit the piston f* to enter it and to pass
by the valve-cylinder m when said piston, in its rotation, approaches the said valve-
cylinder as illustrated by position in Fig. 5.
The concave curvature of the cut-away portion m³ is to be made such as to make
a close joint between it and the outer end of the piston f' during the rotation of
said piston and valve-cylinder, and thus to prevent waste of liquid when the
piston is passing by the valve-cylinder. m³, m³ are webs at the sides of the cut-
away portion m³ as shown in Figs 3 and 4, the space between such webs being
equal to the width of the piston fso as to enable the latter to enter between them
when it passes into the concavity m³ and thus more effectually to prevent leakage
while the piston f' is in the act of passing by the valve cylinder m.
a³, as are lateral grooves on the interior of valve chamber a', in which are
located suitable metal or wood packings m³, m³ held up by means of springs, or
in other equivalent manner, against the outside of the valve cylinder m as shown
in Fig 4, such packings being located near the junction of the respective pump
and valve chambers a and a¹ as shown, so as to effect a close connection between
the exterior of valve-cylinder m and its chamber at such places. m, m, are
segmental packing rings located in corresponding grooves at the ends of the valve-
cylinder m so as to effect a close joint between the ends of the latter and the
corresponding parts of its chamber.
Within the valve chamber a¹, I prefer to make a semi-circular (or nearly so)
cut-away part or segmental space a to permit the valve-cylinder m to move.
with greater ease and with the least frictional resistance. n is the valve cylinder
secured to shaft i directly below the cylinder g; said valve cylinder n is made in
all respects like the valve cylinder m, and like it, it has central hub n¹, skeleton
arms n, n, concave cut away portion n³, webs n', n³, and packings n³, n³, nº, nº,
the only difference between said valve cylinders being in their arrangement upon
the shaft i, for as the pistons f*, g' are arranged on the shaft e in diametrically
opposite directions, so are the cut away portions m³, n³ of the valve cylinders, m, n,.
arranged correspondingly in diametrically opposite directions as shown.
cylinders f, g, and their respective pistons f, gare made to counterbalance each
other on the shaft e, and in a like manner the valve cylinders m, n are arranged
upon the shaft i so as to counterbalance each other accurately, and thus to prevent
any pounding or jarring of the pump while in motion.
The
a² is the delivery opening from the pump chamber a, which opening com-
municates with the air chamber as cast in one piece with the shell a, a¹ and
having an exit a' through which the water is delivered from the pump in a
continuous stream. If the liquid from the pump is to be conducted at any distance
from it, I attach a suitable pipe to the exit a³ in any ordinary manner according
to circumstances.
In using this my improved pump, the liquid or air may be drawn in through
pipe d and delivered through opening a³, or vice versa, according to the direction in
which the shaft is rotated

page_text: The operation of this my improved duplex crank piston pump is as follows:
We will suppose that the pump is to be used for drawing water up through
suction pipe d and to force it out through exit opening a; for this purpose the
shaft e, its cylinders f, g, and pistons f, gare set in a rotary direction shown by.
arrow in Fig 4; the shaft i and its valve cylinders m, n are, by means of gears k, l
accurately coupled to shaft e and made to rotate with equal velocity in an opposite
direction as shown by arrow in said Fig 4.
•
After a few rotations the interior of the pump chamber a is filled with the
liquid which is being drawn up through pipe d and after passing through
opening e, in the head c, it enters the compartments f6, and fƒ in the pump
cylinder fon both sides of the curved and screw propeller shaped wings f" causing
a portion of the liquid to be forced out through opening f3 back of piston f*, into
the pump chamber and the other part of the liquid conducted through channel gⓇ
and forced out through opening gs back of piston g' into the other half of the
pump chamber on the other side of the division wall a³. The water in front of
the respective pistons f, g₁ being forced out through opening a' into air chamber a³
and delivered through exit a' as described.
During this operation, the respective valve cylinders m and n are kept in a
continuous rotary motion in opposite direction to that of the pistons ƒ, g' and
of precisely equal speed with the latter, and in such a manner as to bring the
pistons f g respectively in conjunction with the concavities m³, n³ on the
respective valve cylinders m, n and thus to permit said pistons in their revolutions
to pass by the said valve cylinders without causing leakage in so doing.
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
Ist In a pump, the rotary hollow cylinder f, provided with curved and screw
propeller shaped internal wings f" and formed with an inlet channel at its end,
taid channel on one side of said wings extending through to the opposite end
of the cylinder and on the other side through the periphery thereof substantially
as described.
2nd In a pump the hollow cylinder f formed with a supply channel having
its inlet at the end of said cylinder, a discharge channel leading out through the
periphery of the cylinder, and internal suction wings located in said discharge
channel and forming a continuous guide for the fluid through said channel,
substantially as described.
3rd In a pump, the shell a constituting a piston chamber in combination with
an abutment valve and a cylinder located within said shell and provided with a
piston extending from its periphery and formed with a supply channel com-
municating with an opening through the shell, said opening surrounding the
shaft upon which the cylinder rotates and covering the open end of said cylinder,
the supply channel communicating with the piston chamber through the periphery
of its internal cylinder, the said piston chamber having an exit opening through
the shell substantially as described.
4th In a pump, the rotary hollow cylinder f with its internal guide wings f¹¹, f¹¹,
side openings f³, internal passage f6, piston f', piston packing ƒ³ and segmental
packings, at the outer edges of cylinder f, substantially as described.
5th In a pump, the shell a having recess a¹, the valve cylinder m fitted within
said recess and having the portion m' cut away in combination with the cylinder f
provided with the piston extending from its periphery and formed with an internal
supply channel communicating between the inlet opening cand the piston
chamber, the said inlet opening surrounding the shaft upon which the cylinder
rotates and covering the open end of said cylinder, said shell also having the exit
opening a' and 'the shafts of the cylinder and valve cylinder m geared together
substantially as described,
:

page_text: 6th In a pump, the shell a, a¹ with its perforated division wall a³, the rotary
shafte having attached to it the respective hollow cylinders f, g located side by
side in communication and having diametrically opposed openings f³, g³, and
pistons f, g in combination with the shaft i equally geared to shaft e by means
of gears and land having secured to it the respective valve cylinders m, n, each
one having its cut-away portions m³, n³ arranged in diametrically opposite positions
and balancing each other as set forth and described.
7th In a pump, the shell a, a¹, cast in one piece, the portion a adapted to serve
as a pump chamber for the reception of the rotary piston and intermediate con-
necting mechanism to the driving shaft e and having an air chamber a³ formed
on the side thereof and communicating directly with discharge opening a in
combination with an abutment valve arranged in the part a¹ substantially as
described.
8th In a pump, the shell a, a¹ having grooves a³, a³ for the reception of wood
or metal packings m³, m³ combined with the valve cylinders m, n, secured in
diametrically opposite positions on shaft i, and having segmental packing rings
me, me at the junction of sides and ends of the said respective valve cylinders,
substantially as described.
9th The combination of the shell a, the hollow cylinder of having piston f'
extending from its periphery, the guide and suction wings f11, f forming an
internal supply passage having its inlet at the end and its discharge at the
periphery of said cylinder, the said inlet communicating with the opening cl
through the shell and the supply pipe d covering said opening, and the shaft e
passing through said opening c₁ and the supply pipe d, substantially as described.
10th In a pump, the rotary hollow cylinder with its internal guide or suction
wings f", having outer propeller shaped edges f10 f10 at entrance from supply
pipe d as shown and described to facilitate the passage of the fluid to the interior
of the pump, substantially as described.
11th In a pump, the hollow cylinder having a piston extending from its
periphery and provided with curved internal suction wings forming continuous
guides for the Huid in its passage through an internal channel having its inlet
at the end and its exit through the periphery of said cylinder substantially as
described.