U.S. patent application number 09/898798 was filed with the patent office on 2003-01-09 for slurry piston pump with cylinder cleaning apparatus.
This patent application is currently assigned to Bernard B. Dwyer. Invention is credited to Dwyer, Bernard B..
Application Number | 20030007880 09/898798 |
Document ID | / |
Family ID | 25410048 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030007880 |
Kind Code |
A1 |
Dwyer, Bernard B. |
January 9, 2003 |
SLURRY PISTON PUMP WITH CYLINDER CLEANING APPARATUS
Abstract
A slurry piston pump (10) including a fluid hose (70) coupled
into the back end (26) of a piston cylinder (24) to provide
cleaning and/or lubricating fluid (60) into the interior (23) of
cylinder (24) while allowing cylinder (24) to be directly coupled
to a drive cylinder (12).
Inventors: |
Dwyer, Bernard B.;
(Cincinnati, OH) |
Correspondence
Address: |
Kurt L. Grossman
Wood, Herron & Evans, L.L.P.
2700 Carew Tower
441 Vine Street
Cincinnati
OH
45202-2917
US
|
Assignee: |
Bernard B. Dwyer
7596 Windy Knoll Drive
Cincinnati
OH
|
Family ID: |
25410048 |
Appl. No.: |
09/898798 |
Filed: |
July 5, 2001 |
Current U.S.
Class: |
417/401 ;
417/900 |
Current CPC
Class: |
Y10S 417/90 20130101;
F04B 15/023 20130101 |
Class at
Publication: |
417/401 ;
417/900 |
International
Class: |
F04B 017/00 |
Claims
Having described the invention, what is claimed is:
1. A water box-free dual piston pump for a slurry material
comprising: first and second reciprocating drive rods each having
an end; first and second pistons supported at the respective ends
of the first and second drive rods; first and second piston
cylinders each having a sidewall defining an interior extending
between a back end and a front end, the first and second pistons
being mounted respectively in the interior of the first and second
piston cylinders so as to be movable between the back and front
ends of the respective piston cylinders whereby to pump slurry
material into and out of the front ends of the piston cylinders in
response to reciprocation of the respective drive rods; and a fluid
hose fluidically coupling the back end of the first piston cylinder
to the back end of the second piston cylinder whereby to expose
fluid in the fluid hose to the interiors of the piston cylinders at
the back ends thereof.
2. The pump of claim 1, each piston cylinder including a fluid
fitting on the sidewall thereof adjacent the back end, the fluid
hose coupled to the piston cylinders via the fluid fittings.
3. The pump of claim 2, the fluid fittings being rotatably mounted
to the piston cylinder sidewalls.
4. The pump of claim 1, the fluid hose including first and second
hose sections, each section having a cylinder end and a distal end,
the cylinder end of each hose section being coupled to the back end
of a respective piston cylinder, the distal ends of the hose
sections being selectively coupled together.
5. The pump of claim 4, each piston cylinder including a fluid
fitting on the sidewall thereof adjacent the back end, the fluid
hose section cylinder ends being coupled to the piston cylinders
via the fluid fittings.
6. The pump of claim 5, the fluid fittings being rotatably mounted
to the piston cylinder sidewalls.
7. The pump of claim 4 further comprising a fitting removably
joining the hose section distal ends together in fluid
communication.
8. The pump of claim 7, the fitting removably joining the hose
section distal ends together comprising a cylindrical pipe section
coupled at its respective ends to the distal ends of the hose
sections.
9. The pump of claim 1 further comprising first and second drive
cylinders supporting the first and second drive rods for
reciprocation therein, the first and second drive cylinders being
directly coupled respectively to the back ends of the first and
second piston cylinders.
10. The pump of claim 9 further comprising hydraulic connectors
associated with each of the drive cylinders whereby to
hydraulically control reciprocation of the drive rods.
11. The pump of claim 1, the hose being comprised of flexible
material.
12. A water box-free piston pump for a slurry material comprising:
a reciprocating drive rod having an end; a piston supported at an
end of the drive rod; a piston cylinder having a sidewall defining
an interior extending between a back end and a front end, the
piston being mounted in the interior of the piston cylinder so as
to be movable between the back and front ends thereof whereby to
pump slurry material into and out of the front end of the piston
cylinder in response to reciprocation of the drive rod; and a fluid
hose having a cylinder end and a distal end, the cylinder end of
the fluid hose being fluidically coupled into the back end of the
piston cylinder whereby to expose fluid in the fluid hose to the
drive rod and the interior of the piston cylinder at the back end
thereof.
13. The pump of claim 12 further comprising a cap closing the
distal end of the fluid hose.
14. The pump of claim 12, the piston cylinder including a fluid
fitting on the sidewall adjacent the back end thereof, the cylinder
end of the fluid hose being coupled to the piston cylinder via the
fluid fitting.
15. The pump of claim 14, the fluid fitting being rotatably coupled
to the piston cylinder sidewall.
16. The pump of claim 12, further comprising a drive cylinder
supporting the drive rod for reciprocation therein, the drive
cylinder being coupled directly to the back end of the piston
cylinder.
17. The pump of claim 16 further comprising a hydraulic connector
associated with the drive cylinder whereby to hydraulically control
reciprocation of the drive rod.
18. The pump of claim 12, the hose being comprised of flexible
material.
19. A water box-free dual piston pump for a slurry material
comprising: first and second reciprocating drive rods each having
an end; first and second pistons supported at the respective ends
of the first and second drive rods; first and second piston
cylinders each having a sidewall defining an interior extending
between a back end and a front end, the first and second pistons
being mounted respectively in the interior of the first and second
piston cylinders so as to be movable between the back and front
ends of the respective piston cylinders whereby to pump slurry
material into and out of the front ends of the piston cylinders in
response to reciprocation of the respective drive rods; and a first
and second fluid hose each having a cylindrical end and a distal
end, the cylinder ends being fluidically coupled into the
respective back ends of the first and second piston cylinders
whereby to expose fluid in the first and second fluid hoses,
respectively, to the interiors of the first and second piston
cylinders at the back ends thereof.
20. A method of cleaning or lubricating a slurry material dual
piston pump wherein drive rods extend into an interior of
respective piston cylinders through respective back ends thereof
and are coupled to pistons of the respective piston cylinders, the
respective pistons being movable between the back end and a front
end of the cylinders by reciprocation of the respective drive rods
to pump slurry material into and out of the front ends of the pump
cylinders, the method comprising: fluidically coupling a fluid hose
between the back ends of the first and second piston cylinders;
providing a fluid in the fluid hose; and reciprocating the drive
rods to move the pistons while exposing the fluid in the hose to
the interiors of the piston cylinders.
21. The method of claim 20 wherein the piston cylinders each have a
sidewall defining the interior, the method further comprising
fluidically coupling the fluid hose through the sidewalls of the
piston cylinders.
22. The method of claim 20 further comprising selectively accessing
the fluid hose between the back ends of the first and second pump
cylinders.
23. The method of claim 22 further comprising providing the fluid
in the fluid hose while accessing the fluid hose between the back
ends of the first and second pump cylinders.
24. The method of claim 22 further comprising emptying out the
fluid from the fluid hose while accessing the fluid hose between
the back ends of the first and second pump cylinders.
25. The method of claim 20 further comprising reciprocating the
drive rods so as to move the pistons in unison but in opposite
directions.
26. A method of cleaning or lubricating a slurry material piston
pump wherein a drive rod extends into an interior of a piston
cylinder through a back end thereof and is coupled to a piston of
the piston cylinder, the piston being movable between the back end
and a front end of the piston cylinder by reciprocation of the
drive rod to pump slurry material into and out of the front end of
the piston cylinder, the method comprising: providing a fluid hose
having a cylinder end and a distal end; fluidically coupling the
cylinder end of the fluid hose into the back end of the piston
cylinder; providing a fluid in the fluid hose; and reciprocating
the drive rod to move the piston while exposing the fluid in the
hose to the interior of the piston cylinder.
27. The method of claim 26 wherein the piston cylinder has a
sidewall defining the interior, the method further comprising
fluidically coupling the fluid hose through the sidewall of the
piston cylinder.
28. The method of claim 26 further comprising providing a cap on
the distal end of the fluid hose.
29. The method of claim 28 further comprising removing the cap from
the distal end and providing the fluid in the fluid hose through
the distal end thereof.
30. The method of claim 28 further comprising removing the cap from
the distal end and draining the fluid from the fluid hose through
the distal end thereof.
31. The method of claim 26 further comprising providing fluid in
the fluid hose through the distal end thereof.
32. A method of exposing drive rods of a slurry material dual
piston pump to a fluid without a water box, wherein the drive rods
extend into an interior of respective hydraulic pump cylinders
through respective back ends thereof and are coupled to pump
pistons of the respective hydraulic pump cylinders, the respective
pump pistons being movable between the back end and a front end of
the pump cylinders by reciprocation of the respective drive rods to
pump slurry material into and out of the front ends of the pump
cylinders, the method comprising: providing respective fluid hoses
each having a cylinder end and a distal end; fluidically coupling
the cylinder end of the respective hoses into the back end of the
respective piston cylinders; providing a fluid in the respective
fluid hose; and reciprocating the drive rods to move the pistons
while exposing the fluid in the respective fluid hoses to the
interiors of the respective piston cylinders.
33. The method of claim 32 wherein the piston cylinders each have a
sidewall defining the interiors, the method further comprising
fluidically coupling the fluid hoses through the sidewalls of the
piston cylinders.
Description
BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] The present invention relates to slurry piston pumps, and
more particularly, to such pumps for pumping concrete and the
like.
[0003] II. Description of Prior Art
[0004] Piston pumps are often utilized to pump thick slurry mixes
(examples of which include concrete, cement, stucco, mortar,
gypsum, sludge, silt, mud and topsoil, and bentonite) for
construction and remediation purposes. By way of example, a
concrete pumping truck may include a swing tube which swings back
and forth within a concrete hopper mounted at the back end of the
truck. A piston pump, or a pair of piston pumps in a dual pump,
communicate with the concrete hopper and swing tube.
[0005] Each piston pump includes a drive cylinder which has a drive
rod extending therefrom, with a piston mounted to the exposed end
of the drive rod. The piston extends into a piston cylinder, the
back end of which is axially aligned with the drive cylinder, and
the front end of which communicates into the hopper or with the
swing tube, depending on the position of the swing tube. As a
consequence, as the drive rod reciprocates within the drive
cylinder, the piston is caused to move between the back and front
ends of the piston housing. In the back stroke (during which the
piston moves in a direction away from the front end and towards the
back end), the front end of the piston cylinder opens into the
hopper to pump concrete into the piston housing through the front
end thereof. In the forward stroke (during which the piston moves
in a direction away from the back end and towards the front end),
the front end of the piston cylinder is advantageously coupled to
the swing tube so as to pump the concrete from within the piston
cylinder out through the swing tube, to a delivery hose coupled to
the end of the swing tube so as to pump the concrete to the
construction or remediation site.
[0006] Where a pair of such piston pumps are employed, the drive
rods will typically reciprocate in opposite directions such that
one pump is in the back stroke while the other is in the forward
stroke. The swing tube shifts back and forth between the front ends
of the two piston pump cylinders so as to couple to one of the
piston pumps in the forward stroke for pumping of concrete from
that piston cylinder, while the second piston pump communicates
into the hopper to pump concrete into the piston cylinder of the
second pump.
[0007] In conventional slurry piston pumps, whether a one piston
pump or a dual piston pump, the nature of the slurry material
involved creates a significant amount of debris and buildup which
can interfere with the proper operation of the piston pump. As a
consequence, it has been conventional practice to provide a
so-called water box between the drive cylinder and the piston
cylinder. The drive cylinder is typically attached to one side of
the water box with the piston cylinder being attached to the
opposite side of the water box. The result is to axially align the
cylinder with a fluid receiving space therebetween defined by the
water box. Thus, the drive rod extends from the drive cylinder,
through the water box, and into the pump cylinder. As the drive rod
traverses through the water box, it is cleaned or lubricated by the
fluid in the water box. Additionally, the fluid in the water box is
carried into and out of the piston cylinder behind the piston as it
moves therein so as to clean or lubricate the interior wall of the
piston cylinder as well.
[0008] Use of the water box, however, presents certain drawbacks.
In the first instance, the length of the drive rod must be
sufficient not only to properly move the piston through the piston
cylinder between the ends thereof, but must also take into account
the length of the fluid receiving space introduced between the
drive cylinder and the piston cylinder by virtue of the water box
interposed therebetween. Thus, the drive rod (and its associated
cylinder) must be made sufficiently long to traverse the water box
and to move the piston within its cylinder. Shorter drive rods (and
associated cylinders) are, however, desired.
[0009] Additionally, the respective cylinders are coupled to the
water box by bolts and nuts and the like, some parts of which are
accessible only through the interior of the water box. A typical
water box may be accessible through an opening in the top. Liquid
may be added through that opening. Access to the interior of the
water box in order to reach the components attaching the cylinder
housings thereto for maintenance and repair is also by that top
opening. However, the area over the top of the water box can be
difficult to access. In many situations, the piston pumps form part
of a larger pumping system, such as a concrete pumping truck. The
piston pumps are usually situated in very tight quarters with
respect to the rest of the pumping system making access to the
water box, and especially the interior thereof, very difficult.
[0010] The water box my also have a lid over the top opening.
Often, the lid does not stay in place. As a consequence, the liquid
in the water box, as well as any debris from the slurry material,
may slosh out of the water box creating a spill hazard, especially
during use or movement of the pump system with its attendant
jostling and the like.
SUMMARY OF THE INVENTION
[0011] The present invention provides a slurry piston pump which
eliminates the water box and its attendant drawbacks. To this end,
and in accordance with the principles of the present invention, a
fluid hose is coupled into the back end of the piston cylinder
through the cylinder wall and is situated radially outwardly
therefrom so as to provide a reservoir for the cleaning or
lubricating fluid. The fluid hose has a proximal or cylinder end
coupled, such as through a fitting, to communicate directly into
the back end of the pump cylinder through the cylinder sidewall,
rather than from axially behind the cylinder as in the case of a
water box. The fluid hose is thus coupled to expose the drive rod
and the back side of the piston to the fluid as the drive rod
reciprocates the piston through the piston cylinder, but without
the need for a water box between the drive and piston cylinders and
the disadvantages that would present. Instead, the drive cylinder
may be coupled directly to the piston cylinder thereby shortening
the length of the drive rod (and its associated cylinder).
Additionally, the fluid hose may be flexible, and/or coupled to the
piston cylinder by a fitting that is rotatably mounted to the
piston cylinder sidewall, so that the fluid hose may be routed
comfortably within tight quarters, but otherwise accessible as
necessary. The hose may have a distal end fluidically remote from
the cylinder end and through which fluid may be introduced into, or
removed from, the hose. Access to the distal end is accomplished
simply by manipulating the hose or rotating it about the
coupling.
[0012] Where the piston pump has its own fluid hose, the distal end
thereof may have a removable cap so as to selectively seal the
fluid hose and the related piston cylinder. As a result, the fluid
and any debris is kept from splashing out and creating a hazard
while the piston pump is in use or being transported. If the hose
is held in an upward vertical orientation, the cap may be vented so
as to allow fluid to enter and leave the fluid hose from or to the
piston cylinder without expelling out of the fluid hose or building
up pressure therein. Alternatively, an expandable chamber or
reservoir may be included in the hose or cap to accommodate
pressure changes in the hose.
[0013] The above may be applied to individual slurry piston pumps
whether a single, dual or other multiple pump piston system is
employed. However, where a dual pump system is employed, it may be
advantageous to couple together the fluid hoses associated with
each piston cylinder. To this end, a fluid hose may extend between
the back ends of the two piston cylinders so as to fluidically
couple them through the same hose thereby exposing both drive rods
and piston cylinders to the fluid in the hose. The hose in the dual
piston pump system may be comprised of two separate hoses, referred
to in that case as hose sections, each with a cylinder end coupled
to the respective piston cylinders. A further fitting may be
provided to selectively couple the distal ends of the hose sections
together into, effectively, a single fluid hose. The flexibility of
the hose and/or the rotatable fittings at the piston cylinders
allows the hose to be situated in tight quarters, yet access
thereto is easily gained. To fill the hose with liquid, or remove
liquid therefrom, the further fitting joining the sections together
may be unclamped or otherwise opened to thereby gain access to the
distal end(s) of the hose section(s).
[0014] By virtue of the foregoing, there is thus provided a slurry
piston pump which eliminates the water box and its attendant
drawbacks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with the general description of the
invention given above and the detailed description of the
embodiments given below, serve to explain the principles of the
present invention.
[0016] FIG. 1 is a perspective view, partially broken away, of a
single slurry piston pump having a fluid hose in accordance with
the principles of the present invention;
[0017] FIG. 2 is a perspective view of a dual slurry piston pump
utilizing two of the piston pumps of FIG. 1 and having joined fluid
hose sections in accordance with the principles of the present
invention; and
[0018] FIG. 3 is an end view taken along lines 3-3 of FIG. 2.
DETAILED DESCRIPTION OF THE DRAWINGS
[0019] With reference to FIG. 1, there is shown a single slurry
piston pump 10 for purposes of explaining the principles of the
present invention. Piston pump 10 includes a drive cylinder 12
having a drive rod 14 reciprocally mounted therein. Drive rod 14
has an end 15 extending out from cylinder block 16 of drive
cylinder 12 and is caused to move into or out of cylinder 12 under
hydraulic pressure coupled into cylinder 12 through hydraulic
connecter 18 on block 16. To this end, connector 18 is coupled
through a hydraulic hose 19 to a source of controlled hydraulic or
air pressure (not shown). Piston pump 10 further includes a piston
20 mounted to the exposed end 15 of drive rod 14. Piston 20 is
fitted within the interior 23 of a piston cylinder 24 so as to be
moveable between a back end 26 of cylinder 24 and a front end 28
thereof as drive rod 14 reciprocates. More specifically, in a
forward stroke of piston 10, the piston 20 moves in a direction
away from back end 26 and towards front end 28 as indicated by
arrow 30. In a back stroke of piston 20, the piston 20 moves in a
direction opposite to that of arrow 30 and thus moves in a
direction away from front end 28 and towards back end 26.
[0020] Piston cylinder 24 is coupled at its back end 26 directly to
cylinder block 16 of drive cylinder 12 so as to axially align
cylinder 24 and 12, but without an intervening water box (not
shown). The front end 28 of piston cylinder 24 is open to receive
or expel slurry material. To this end, front end 28 of pump 10 is
mounted to a support collar 32 which is on rear wall 34 of a
concrete hopper 36 (shown in phantom lines in FIG. 1). A plurality
of elongated tie rods 37 (only three are shown although four are
present in the pump 10 of FIG. 1) are secured at threaded ends 38
to cylinder block 16 such as by nuts 39, and the other ends 40 are
similarly secured to wall 34 of hopper 36 to constrain cylinder 24
therebetween. As a result, piston cylinder 24 is thus held directly
to cylinder block 16 at back end 26 and to collar 32 and wall 34 at
front end 28. Wall 34 includes an aperture 41 concentric with
collar 32 so as to allow front end 28 of drive cylinder 24 to open
into hopper 36 through wall 34.
[0021] Situated within hopper 36 is a swing tube 42 which is shown
in FIG. 1 in a first position wih its inlet end 44 confronting and
communicating through aperture 41 with front end 28 of piston
cylinder 24 so as to pump slurry material 46 within cylinder 24
into swing tube 42 via front wall 49 during the forward stroke of
piston 20, such that the material 46 is forced out from the
discharge end 48 of swing tube 42 via front wall 49 to a delivery
hose (not shown) attached thereto. Swing tube 42 is moveable to and
from a second position in which its inlet end 44 is moved out of
alignment with piston cylinder 24 so as to expose front end 28
thereof into the interior 50 of hopper 36. In that state, as piston
20 is driven through its back stroke, slurry material 46 in hopper
36 will be pumped into cylinder 24 for pumping out through swing
tube 42 during the next forward stroke of piston 20 when swing tube
42 moves back to the first position shown in FIG. 1. Although the
swing tube 42 and hopper 36 are described herein, it will be
understood that other slurry supply and delivery mechanisms could
be employed. The swing tube and hopper are thus not directly part
of the piston pump 10 and are instead shown merely by way of
example, and not limitation.
[0022] It will be appreciated that as piston 20 moves through its
strokes within piston cylinder 24, debris 47 from slurry material
46 may accumulate therein. The debris may foul the interior surface
54 of the sidewall 56 defining the interior 23 of cylinder 24,
and/or may also foul drive rod 14. To reduce or eliminate that
fouling, it is desirable to expose the drive rod 14 and the back
end 58 of piston 20 (and thus those aspects of surface 54
therebehind) to a cleaning or lubricating fluid 60 such as water
(where freezing is not an issue), or hydraulic or oil fluid. To
this end, a fluid fitting such as an elbow 62 is mounted to the
sidewall 56 of piston cylinder 24 adjacent, and advantageously just
ahead of, back end 26 thereof so as to provide fluidic access into
the interior 23 of piston cylinder 24 through cylinder wall 56. The
proximal or cylinder end 64 of a fluid hose 70 is placed onto
fitting 62 and clamped in place, for example, by a hose clamp 72,
such that hose 70 is situated radially outwardly of cylinder 24
rather than between cylinders 12 and 24. Fluid 60 is placed into
fluid hose 70 through the distal end 74 thereof.
[0023] Hose 70 may be comprised of flexible material such as
polyurethane or PUC, and/or fitting 62 may be rotatably mounted to
wall 56 at back end 26 of piston cylinder 24, so as to allow hose
70 to be placed into an upright position (as at U) as indicated by
arrow 80 in FIG. 1, or to be moved into a downward position (as at
D) as indicated by arrow 82. In the upright position as at U, the
distal end 74 of hose 70 may be accessed so as to allow fluid 60 to
be poured into hose 70 such as from a container 86. A cap 90 may be
securely fitted against distal end 74 and held in place such as
with a hose clamp 92 so as to seal hose 70 and prevent fluid 60
from leaking out of hose 70 and/or piston cylinder 24 in use. To
empty the fluid 60 therefrom as well as any debris 47 from material
46, with hose 70 in the downward position as at D and cap 90
removed from end 74, fluid 60 and debris 47 will flow out of hose
end 74 to be retrieved such as in a basin 94 positioned
therebelow.
[0024] Hose 70, if of a flexible material, may be of any material
suitable for use with fluid 60 under pressure. Hose 70 may
advantageously be cleared with wire braiding (not shown) for
structural rigidity. The clear hose 70 has the advantage that the
fluid 60 may be monitored for build up of debris 47 to know when to
change fluid 60. One such hose is K7130 Polywire.TM. wire
reinforced Kuri Tec.RTM. hose with heavy wall available from
Kuriyama of America, Inc. An eighteen inch length of hose 70 may be
used having a 11/4" or 11/2" diameter, for example, although other
lengths and diameters may be employed as desired.
[0025] Although cap 90 is shown as secured to end 74 by a clamp 92,
it will be appreciated that end 74 could alternatively be provided
with a threaded fitting (not shown) by which to threadably and
removably receive a threaded cap (not shown) thereon. Also cap 90
may normally seal hose 70. However, where hose 70 is held, in use,
in the upward position as at U, cap 90 may instead be vented (not
shown) so as to allow fluid 60 to flow back and forth between hose
70 and cylinder 24 without pressure build-up problems.
Alternatively, cap 90 may seal end 74 of hose 70, and an expandable
reservoir (not shown) may be coupled to hose 70, such as between
end 74 and cap 90, or built into cap 90, to accommodate pressure
variation within hose 70.
[0026] In use of piston pump 10, swing tube 42 will be placed out
of alignment with piston cylinder 24 during a back stroke of piston
20 so as to pump concrete 46 from hopper 36 into cylinder 24
through front end 28. On that back stroke, fluid 60 within the
interior 23 of cylinder 24 behind piston 20 will be forced out of
cylinder 24 and into fluid hose 70. On the forward stroke of piston
20, swing tube 42 will be aligned with front end 28 of cylinder 24
so as to pump concrete material 46 or the like out of cylinder 24
through swing tube 42. Also, on the forward stroke of piston 20,
drive rod 14 will project into cylinder 24 to be cleaned and/or
lubricated by fluid 60 from hose 70. Fluid 60 will also fill into
cylinder 24 behind piston 20 from hose 70 so as to clean and/or
lubricate the interior surface 54 of piston cylinder wall 56. The
above thus provides the function of a water box but without the
disadvantages thereof.
[0027] With reference to FIG. 2, a dual piston pump 100 is shown.
Dual piston pump 100 includes two essentially identical piston
pumps 10 as shown in FIG. 1, with identical reference numbers as in
FIG. 1 with the additional designation a or b to distinguish
between the two. Pumps 10a and 10b operate together to provide
pumping action of the concrete or other slurry material 46. To this
end, the cylinder blocks 16a, 16b of the respective drive cylinders
12a, 12b are coupled together by a bracket plate 102 receiving some
of the tie rods 37a, 37b. The front ends 28a, 28b of the respective
piston cylinders 24a, 24b are also held to respective ones of a
pair of support collars 32a, 32b so as to be accessible through
apertures 41a and 41b to open into hopper 136 via rear wall 134
thereof.
[0028] The distal ends 74a, 74b of the hose sections 70a, 70b may
be provided with a cap and/or reservoir as above-described so that
hose sections 70a, 70b are independent, or they may advantageously
be fluidically coupled together as will now be described. To that
end, a further fitting 150 such as a cylindrical 11/2" length of
plastic connecting pipe has its formed ends 152, 154 received into
the distal ends 74a, 74b of hose sections 70a, 70b. Hose clamps
156, 158 may be used to clamp each end 152, 154 to respective hose
sections 70a, 70b. As a result, an essentially continuous hose 170,
is created that couples fluid 60 to the drive rods 14a, 14b and
cylinders 24a, 24b as the respective pistons 20a, 20b reciprocate.
Typically, the pistons 20a, 20b are caused to reciprocate in
opposite directions so that as piston 20a, for example, is on the
back stroke, the other piston 20b is in the front stroke, or vice
versa. The swing tube 42 may be moved back and forth by plate 172
rotated back and forth about axle 174 so as to selectively couple
its inlet end 44 to the piston pump 10b, for example, which is in
the forward stoke, to pump concrete out from the front end 28b,
while front end 28a of the other pump 10a is open into hopper 136
to thereby pump concrete 46 into the piston cylinder 24a thereof.
Also, when pistons 20a, 20b move in opposite directions, fluid 60
in hose sections 70a, 70b may be pushed back and forth between
cylinders 24a, 24b to thus provide even greater cleaning or
lubricating action or capacity.
[0029] To provide fluid 60 into hose sections 70a, 70b or to remove
fluid 60 (and debris 47 from material 46) therefrom, one of clamps
156 or 158 may be removed to allow the associated end 152 or 154 to
be pulled out from the distal end 74a, 74b of a hose section 70a or
70b, which may then be placed in the up (U) or down (D) position as
previously described for filling or emptying of hose 70 in FIG. 1.
Alternatively, if fitting 150 is a T-connector (not shown), the tee
portion thereof may have a threadably removable cap for access to
hose 170 without releasing clamps 156, 158.
[0030] As can be seen from the above, the drive rod 14 and interior
surface 54 of the piston cylinder 24 are cleaned and/or lubricated
without the need for a water box (not shown) and its attendant
drawbacks. The drive rod 14 may thus be made short enough simply to
handle the length of the stroke of the piston cylinder 24 without
also taking into account the added length of a water box thereby
shortening the overall length of the slurry piston pump 10.
Moreover, the drive cylinder 12 and piston cylinder 24 may be
directly coupled together such that the parts joining them together
are accessible exteriorally thereof and without reaching into a
water box which may be unduly confining and difficult to
manipulate. Further, the fluid hose 70 may be sealed from the
environment so that it does not have a tendency to slosh fluid
and/or debris either in use or during transportation of the slurry
piston pump 10 thereby eliminating the spill hazards thereof. Still
further, the hose 70 may be readily accessed for filling and/or
emptying without being unduly limited in access thereto.
[0031] By virtue of the foregoing, it is thus seen that there is
provided a slurry piston pump which eliminates the water box and
its attendant drawbacks.
[0032] While the present invention has been illustrated by the
description of various embodiments thereof, and while the
embodiments have been described in considerable detail, it is not
intended to restrict or in any way limit the scope of the appended
claims to such detail. Additional advantages and modifications will
readily appear to those skilled in the art. For example, hose 70
could be made up of rigid steel tubing instead of flexible
material. Also, hose 70 may be more permanently joined to the wall
56 of piston cylinder 24 than the releasable connection provided by
clamp 72 as shown herein. The hose 70 may also extend out and away
from cylinder 24 or may be looped around in any desired fashion,
such as may be dictated by the cramped quarters in which the pump
10 is to be placed. Also, fluid 60 is exposed to the drive rod 14
and the interior 23 of cylinder 24 behind piston 20.
Advantageously, piston 20 has a relatively close fit within
cylinder 24. It will be appreciated that the fit will not be very
tight, however, such that some fluid 60 may seep past piston 20 to
flow ahead of the piston 20. The invention in its broader aspects
is therefore not limited to specific details, representative
apparatus, and methods and illustrative examples shown and
described. Accordingly, departures may be made from such details
without departing from the scope or spirit of applicant's general
inventive concept.
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