EP1536135A2

EP1536135A2 - A pump

Info

Publication number: EP1536135A2
Application number: EP04028061A
Authority: EP
Inventors: John D. Padgett; Daniel P. Strauser
Original assignee: Elgin Sweeper Co
Current assignee: Elgin Sweeper Co
Priority date: 2003-11-26
Filing date: 2004-11-25
Publication date: 2005-06-01
Also published as: EP1536135A3; US20050142012A1

Abstract

A closed loop rodder pump is disclosed which can include a tube assembly and a reciprocating cylinder assembly disposed therein. The cylinder assembly can include a piston portion and a plunger. The piston portion can sealingly engage the tube assembly. In some embodiments, the cylinder assembly can include a second plunger to provide the pump with a dual-acting feature. The rodder pump can be used in a water jetter cleaning system of a vehicle for cleaning catch basins and/or sewers.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 60/525,349, filed November 26, 2003, the entire disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates in general to a reciprocating pump driven by pressurized fluid from a hydraulic pump and more particularly to a closed-loop, hydraulically-driven rodder pump.

BACKGROUND OF THE INVENTION

Heretofore vacuum cleaning of catch basins and flushing of sewer pipes has required the use of at least two separate vehicles. A first vehicle with a hose reel mounted on the rear end thereof was positioned at the manhole and a high pressure hose fitted with a jet nozzle was introduced into the sewer. Water from a tank on the vehicle was pumped through the hose at pressures at about 1,000 pounds per square inch to drive the hose through the pipe against the water flow. Pressure drops along the hose length were considerable and at 400 feet, available pressures were only about 600 to 800 pounds per square inch. Debris flushed from the sewer pipe was then sucked out of the catch basin by a second follow-up vehicle. This multiple vehicle system duplicated personnel and the rear mounted hose reel exposed the personnel to traffic hazards.
A single vehicle for vacuum cleaning of catch basins and flushing of sewer pipes with water surged through a hose and nozzle at pressures of about 2,000-3,000 pounds per square inch is known, an example being disclosed and described in U.S. Patent No. 3,658,589, entitled, "Catch Basin And Sewer Pipe Cleaner." Such a vehicle is typically provided with a pump to deliver water at operating pressure for cleaning the catch basins and sewer pipes. An engine-driven oil pump, located either on the vehicle or remotely therefrom, can hydraulically drive the pump.

SUMMARY OF THE INVENTION

The invention provides a closed-loop, hydraulically-driven rodder pump. The pump of the present invention seeks to improve upon the piston pump shown and described in U.S. Patent No. 3,700,360, entitled, "Double-Acting Tandem Piston Pump," which is incorporated herein by this reference in its entirety.
The present invention can be used in a vehicle for cleaning sewer pipes and catch basins by the use of water pressure and the carry ing power of moving air. In one embodiment, a combined catch basin and sewer pipe cleaning vehicle includes a large debris collecting dump body from which air is continuously pulled by an engine driven fan on the vehicle and easily opened for dumping. The vehicle also has a separate water tank, a reciprocating water pump driven by pressurized oil from a vehicle engine-driven hydraulic pump, and a reeled high pressure hose with a self-propelling jet nozzle receiving surges of high pressure water from the water pump, which can be in the form of a closed-loop, hydraulically-driven rodder pump. In other embodiments, the rodder pump of the present invention can be used in other vehicles, such as, hydroexcavaters, for example.
In one aspect of the invention, a pair of single cylinder reciprocating rodder pumps can be provided in a closed loop system. In yet another embodiment, a single rodder pump having a dual-acting cylinder assembly can be provided in a closed loop system.
These and other features of the present invention will become apparent to one of ordinary skill in the art upon reading the detailed description, in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a perspective view of an embodiment of a pump according to the present invention.
FIG. 2 is a front elevational view of the pump of FIG. 1.
FIG. 3 is an enlarged detailed view taken from FIG. 2 of the pump of FIG. 1.
FIG. 4 is an enlarged detailed view taken from FIG. 2 of the pump of FIG. 1.
FIG. 5 is an enlarged detailed view taken from FIG. 2 of the pump of FIG. 1.
FIG. 6 is a first end view of the pump of FIG. 1.
FIG. 7 is a second end view of the pump of FIG. 1.
FIG. 8 is a diagrammatic view of an input circuit for a pair of pumps as shown in FIG. 1, which is configured as a deintensifier circuit.
FIG. 9 is a perspective view of another embodiment of a pump according to the present invention.
FIG. 10 is a perspective view of cylinder assembly of the pump of FIG. 9.
FIG. 11 is a front side elevational view, partially in section, of the pump of FIG. 9.
FIG. 12 is a fragmentary top view of the pump of FIG. 9.
FIG. 13 is an enlarged detailed view taken from FIG. 11 of the pump of FIG. 9.
FIG. 14 is a bottom view, partially in section, of the pump of FIG. 9.
FIG. 15 is an enlarged detailed view taken from FIG. 14 of the pump of FIG. 9.
FIG. 16 is an end view of the pump of FIG. 9.
FIG. 17 is a cross-sectional view taken along line 17-17 in FIG. 11 of the pump of FIG. 9.
FIG. 18 is a cross-sectional view taken along line 18-18 in FIG. 14 of the pump of FIG. 9.
FIG. 19 is a cross-sectional view taken along line 19-19 in FIG. 14 of the pump of FIG. 9.
FIG. 20 is a cross-sectional view taken along line 20-20 in FIG. 14 of the pump of FIG. 9.
FIG. 21 is a cross-sectional view of a check valve suitable for use with the pump of the present invention.
FIG. 22 is a diagrammatic view of an input circuit which includes the pump of FIG. 9.
FIG. 23 is a side elevational view of a vehicle for cleaning sewer pipes and catch basins that includes a pump according to the present invention.
FIG. 24 is a somewhat schematic perspective view, partially in section, of another embodiment of a rodder pump according to the present invention having a dual-acting cylinder.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1-7, an embodiment of a pump 50 according to the present invention is shown that includes a single acting cylinder 52 (see FIG. 2). Referring to FIG. 1, the pump 50 includes first and second tube assemblies 54, 56. The first tube assembly 54 has a butt fitting 58 mounted thereto at a first end 59 thereof. The butt fitting 58 can include a first hydraulic port 60. Disposed at the other end 61 of the first tube assembly 54 is a gland assembly 62. The second tube assembly 56 can have a pair of flanges 64, 65 disposed at the respective ends thereof. The first and second tube assemblies 54, 56 can be mounted together by a tie rod assembly 68, which can comprise a plurality of tie rods 69 extending through the butt fitting 58, the gland assembly 62, and the first flange 64 of the second tube assembly 56 and a plurality of bolts 70 threadedly engaged with the tie rods 69 to retain the first and second tube assemblies 54, 56 in substantially fixed relationship relative to each other.
The first tube assembly 54 can include a second hydraulic port 78 disposed adjacent the second end 61 thereof and a pair of sensor ports 82, 83 disposed respectively adjacent the first and second ends 59, 61 of the first tube assembly 54. The sensor ports 82, 83 can each be sized to respectively accommodate a sensor configured to detect the presence of the cylinder when it is in proximity thereto. The first hydraulic port 60 can be configured as a No. 16 SAE port, for example, and the second hydraulic port 78 can be configured as a No. 8 SAE port, for example. The second tube assembly 56 can include a fluid port 86 in the second flange 65 disposed in axial alignment with the tube portion thereof.
Referring to FIG. 2, the cylinder assembly 52 is disposed within the first tube assembly 54 and is reciprocally movable over a discharge stroke, when moving in a discharge direction 88, and over a suction stroke, when moving in a charge direction 89. The cylinder assembly 52 can include a plunger 90 having a large diameter section 92 and a small diameter section 94, a piston portion 96 mounted to the plunger 90 via a lock nut 98 which is threadedly engaged with the small diameter section 94 of the plunger 90. The cylinder assembly 52 is shown in FIG. 2 in a discharge or power position wherein the cylinder assembly is ready to discharge fluid from the fluid port 86 through a pressure stroke. The piston portion 96 is in sealing contact with an interior surface 99 of the first tube 54. The plunger 90 extends through an opening 100 defined by the gland 62 and the first flange 64 such that at least a portion of the plunger 92 is disposed within the second tube assembly 56. The plunger 90 is in sealing contact with the gland 62.
Referring to FIG. 3, the first port 60 is in fluid communication with the interior of the first tube assembly 54. The butt fitting 58 can include a circumferential groove 104 which can receive a back-up washer 106 and an O-ring seal 108 to provide a sealed connection between the butt fitting 58 and the first tube.
Referring to FIG. 4, the first sensor port 82 can be configured to receive a suitable sensor therein, such as a Hall effect sensor, for detecting the position of the cylinder assembly. The sensor port 82 can include a back-up washer 110 and an O-ring seal 112 therein for sealingly engaging the sensor 109 inserted therein. The sensor can detect when the piston portion 96 is proximate the first sensor port and send a control signal to a controller to operate various valves in response to the position of the cylinder assembly. The sensor can be electrically connected to the controller via an electrical wire, for example. When the piston portion 96 is proximate the first sensor port 82, the cylinder assembly is in a discharge position and is ready to undergo the pressure stroke. In some embodiments, the sensor can be a magnetic field sensor, such as one commercially available from Balluf Inc. of Florence, Kentucky, including one of the sensors designated under the series BMF 32M, including, for example, the sensor referenced with part number BMF-32M-PS-C-2-S49, for example.
Referring to FIG. 2, the second sensor port 83 can sealingly house a similar sensor. The second sensor port 83 is disposed such that it can detect when the cylinder assembly is in a charge position and is ready to undergo the suction stroke by moving in the charge direction 89.
Referring to FIG. 4, the piston assembly 96 can include a wear ring 118 and a seal 120 made from any suitable material, such as, any suitable fluoropolymer resin sold under the Teflon® brand by E. I. duPont de Nemours and Company, for example. The wear ring 118 and the seal 120 are disposed circumferentially around the piston 96 in a pair of grooves 122, 124, respectively. An O-ring 126 can be provided that is in sealing engagement with the piston assembly 96 and the small diameter section 94 of the plunger 90, as shown in FIG. 2.
Referring to FIG. 5, the gland assembly 62 can include a breather 130 which communicates with the interior of the first tube assembly 54. The gland assembly 62 can include a back-up washer 132 and an O-ring seal 134 disposed in a circumferential groove 136. A Z-seal 140 can extend around the breather 130 and be in contacting relationship with the plunger 90. A wiper 142 can extend from the gland assembly such that it is in contacting relationship with the plunger 90. An O-ring seal 146 can be disposed between the gland assembly 62 and the first flange 64 of the second tube assembly.
Referring to FIG. 6, the butt fitting 58 is shown. Referring to FIG. 7, the second flange 65 of the second tube assembly is shown. The fluid port 86 can have a chamfered perimeter 148. The second flange 65 can include a plurality of mounting bores 149.
Referring to FIG. 2, to move the cylinder assembly 52 in the discharge direction 88, hydraulic fluid can be conveyed through the first hydraulic port 60 such that it acts upon the piston portion 96 of the cylinder 52, thereby driving the large diameter section 92 of the plunger 90 into the second tube assembly 56. Once the piston assembly 96 is disposed adjacent the second sensor port 83, the sensor disposed therein can detect the presence of the piston assembly and, in turn, signal the controller to cease the flow of hydraulic fluid through the first hydraulic port 60 and to initiate the flow of hydraulic fluid through the second hydraulic port 78. The hydraulic fluid flowing through the second hydraulic port 78 can act upon the piston assembly 96 of the cylinder assembly 52, thereby driving the cylinder assembly 52 in the charged direction to move the cylinder assembly through the section stroke. Once the piston assembly 96 is adjacent the first sensor port 82, the sensor disposed therein can signal the controller to cease the flow of hydraulic fluid through the second hydraulic port 78 and to initiate the flow of hydraulic fluid through the first hydraulic port 60, thereby sending the cylinder 52 in the discharge direction to travel over the pressure stroke yet again. The pump 50 can continue to operate in this sequence, reciprocating between the pressure stroke and the suction stroke.
Any suitable valving can be used to allow fluid, such as water, for example, to selectively enter the second tube assembly 56 via the fluid port 86 where the plunger can act upon the fluid during the pressure stroke so that pressurized fluid can exit the fluid port 86. In some embodiments, the second tube assembly can include a pair of fluid ports, with one port for receiving fluid therethrough for delivering fluid to the pump to be acted upon by the cylinder assembly, and the other port for discharging pressurized fluid from the pump. The fluid entering the second tube assembly can be pressurized to an initial level by any suitable pump before the cylinder assembly acts upon it.
Referring to FIG. 8, an embodiment of a closed loop pump circuit 170 is shown. The pump circuit 170 is configured to have a 1:1 ratio between input and output. The pump circuit 170 can include a pair of pumps 50, 51 that are both similar to the pump shown in FIG. 1. The pumps 50, 51 can be fluidly connected to each other via a connecting line 172 connecting the first hydraulic po rts 60 to each other. The pump circuit 170 can also include a valve package 180 and a pump and tank assembly 182.
The valve package 180 can be connected to the second hydraulic ports 78 of the pumps 50, 51 by first and second drive lines A, B, respectively. The valve package 180 can be operated to selectively deliver hydraulic fluid to the pumps 50, 51 based upon the valve condition of the valve package. The valve package 180 and the sensors disposed in the first and second pumps 50, 51 can be electrically connected to a controller to allow the valve package to change its valve condition in response to the position of the cylinders 52 within the pumps 50, 51, which positions can be communicated to the controller by the sensors. The valve package 180 can be operated to selectively drive the pumps 50, 51 such that the pumps operate in tandem with the cylinder assemblies 52 operating in alternating sequence. The first pump 50 can be moving through a pressure stroke while the second pump is undergoing a suction stroke and vice versa. The sensors can communicate with the valve package 180 via the controller to yield the desired operation.
The valve package 180 can include a directional valve 184 to direct the hydraulic fluid through one of the drive lines A, B, a pilot valve 186 connected to the directional valve 184 and to the controller, a relief valve 188, and first and second control valves 190, 191 and check valves 192, 193 interposed between the pilot valve 186 and the directional valve 184. The pilot valve 186 is provided to operate the directional valve 184 based upon the signals the pilot valve 186 receives from the controller. The pilot valve 186 can operate to selectively change the condition of the directional valve 184 to produce the desired operation of the pumps 50, 51.
The pump and tank assembly 182 can include a pump 196 and a tank 198 and can include a plurality of filters.
In operation, hydraulic fluid can be delivered through the second drive line B to the second hydraulic port 78 of the second pump 51 whose cylinder assembly 52 moves in response thereto in the charge direction 89. The cylinder forces hydraulic fluid in the second pump 51 out of the first port 60 thereof through the line 172 and into the first port 60 of the first pump 50. The hydraulic fluid entering the first pump 50 acts upon the cylinder assembly 52 therein, moving the cylinder 52 in the discharge direction 88. The cylinder assembly 52 of the first pump 50 can act upon fluid disposed in the second tube assembly thereof to drive the fluid out of the first pump 50 in a pressurized condition. When the cylinder assembly 52 of the first pump 50 reaches the end of the pressure stroke, the second sensor can sense that the piston is proximal thereto and send a signal to the controller to that effect. The controller can communicate with the pilot valve 186 to redirect the drive flow through the directional valve 184 so that hydraulic fluid runs through the first drive line A into the second port 78 of the first pump to reverse the sequence described above.
In another embodiment, the closed loop circuit can be arranged to be an intensifier circuit by running a connecting line 173 between the second hydraulic ports 78 of the pumps 50, 51 and running first and second drive lines A', B' to the first hydraulic ports 60 of the pumps 50, 51. The intensifier ratio can be based upon the surface area of the end of the plunger in relation to the surface area of the annulus defined by the part of the piston portion of the cylinder assembly which extends radially beyond the plunger. In one embodiment, the ratio of the area of the end of the plunger to the area of the annulus of the piston is about 2:1. In yet other embodiments the intensifier ratio can be varied by changing the diameters of the annulus and/or the end surface of the plunger.
Referring to FIGS. 9-20, another embodiment of a pump 250 according to the present invention is shown. The pump 250 includes a dual-acting cylinder 252 (see FIG. 10). Referring to FIG. 9, the pump 250 include three tube assemblies 254, 255, 256 which define a first pressure chamber, a hydraulic chamber, and a second pressure chamber, respectively. The second tube assembly 255 is disposed between the first and third tube assemblies 254, 256. The first and third tube assemblies 254, 256 each have a butt fitting 258 mounted thereto. The second tube assembly 255 can have a gland assembly261, 262 mounted at each end thereof. A tie rod assembly 268, which includes a plurality of tie rods 269 and a plurality of bolts 270 threadedly engaged therewith, can be provided to connect the various components together. The pump 250 is a dual acting pump in that the cylinder can movably reciprocate within the tubes under the influence of a hydraulic fluid selectively entering first and second hydraulic ports 260, 278 in fluid communication with the hydraulic chamber defined by the second tube assembly 255 to alternatingly discharge pressurized fluid from the first and third tubes 254, 256.
Referring to FIG. 9, the pump 250 can include a first sensor port 282 and a second sensor port 283. The sensor ports 282, 283 can be configured to respectively accommodate a sensor that is configured to detect when the piston portion 296 is in proximity therewith. The sensors disposed in the first and second sensor ports 282, 283 can be electrically connected to a controller, as described above in connection with the pump 50 of FIG. 1, to selectively control the flow of hydraulic fluid through the first and second hydraulic ports 260, 278 to reciprocally move the dual-acting cylinder 252 to alternatingly discharge pressurized fluid from the first and third tubes 254, 256 through the butt fittings 258 mounted thereto.
Referring to FIG. 10, the cylinder assembly 252 can include first and second plungers 290, 291 and a piston portion 296 interposed between the plungers. Each plunger 290, 291 can be similar to the plunger 90 of the pump 50 shown in FIGS. 1-7 and as described above. The piston portion 296 can be similar to the piston portion 96 of the pump 50 of FIGS. 1-7 as described above.
Referring to FIGS. 12 and 13, the first sensor port 282 is shown. The first sensor port 282 can be similar to the first sensor port 82 of the pump 50 of FIG. 1. The second sensor port 283, shown in FIG. 9, can be similar to the first sensor port 282.
Referring to FIGS. 14 and 15, the first gland assembly 261 is in sealing relationship with the first plunger 290. The second gland assembly 262 is in sealing contact with the second plunger 291. The first and second gland assemblies 261, 262 can each be similar to the gland assembly 62 of the pump 50 of FIG. 1. The piston portion 296 has a larger diameter than either of the plungers 290, 291 and is disposed within the hydraulic. tube 255. The piston 296 is configured such that it can reciprocate within the hydraulic tube 255 but cannot enter either of the pressure tubes 254, 256. The first and second plungers 290, 291 are configured such that they can enter the first and second pressure tubes 254, 256, respectively. The entire cylinder assembly 252 can reciprocate within the tube assemblies such that the first plunger 290 is undergoing a charge stroke while the second plunger 291 is undergoing a discharge stroke and vice versa.
Referring to FIG. 16, one of the butt fittings 258 is shown. In practice, the butt fitting may be rotated about the longitudinal axis of the pump 250 over a predetermined angle 297, such as 21°, for example, from the position shown in FIG. 11. Referring to FIG. 17, an integrated dual check valve or a suction and discharge valve cartridge 352 can be disposed within a cavity 354 of each butt fitting 258. The valve cartridge assembly 57 as shown and described in U.S. Patent No. 4,878,815 to Stachowiak, which is incorporated in its entirety herein by this reference, and the Uni-Valve cartridge assembly sold by Jetstream of Houston LLP are exemplary valves for use as the valve cartridge 352. The butt fitting 258 can have an inlet port 356 for admitting fluid to be pressurized within the pressure tube 254 to which the butt fitting 258 is mounted and an outlet port 357 for allowing pressurized fluid to leave the pressure tube 254 for use downstream of the pump. The valve cartridge 352 is disposed between the inlet and outlet ports 356, 357 and the pressure tube to selectively allow and prevent fluid flow therethrough such that fluid can flow from the inlet port to the tube, but not to the outlet port, and fluid can flow from the tube to the outlet port, but not to the inlet port.
Referring to FIG. 18, the butt fitting 258 is shown with the valve cartridge 352 removed therefrom. The inlet port 356 is in communication with the cavity 354. The cavity 354 includes a weep hole 258 to provide an indicator in the event the valve cartridge fails. The cavity 354 includes a stepped configuration to retain the valve cartridge therein.
Referring to FIG. 19, the first plunger 290 closely conforms to the first tube 254. Referring to FIG. 20, the second plunger 291 is relatively smaller than the hydraulic tube 255. The second plunger 291 can closely conform to the second pressure tube.
Referring to FIG. 21, in other embodiments of the pump, a check valve 353 can be paired with another similar check valve in lieu of the integrated dual check valve 352 shown in FIG. 17. The check valve 353 shown in FIG. 21 is an example of a suitable check valve for use with the pump and is similar to the valve which has been commercialized by National Oil Well and is similar to the valve shown and described in U.S. Patent No. 4,667,697, entitled "Unitized Check Valve," which is incorporated in its entirety herein by this reference.
Referring to FIG. 21, another embodiment of a closed loop pump circuit 370 is shown. The circuit 370 can include a charge pump 376, an electrical control package 378 including a plurality of proportional solenoids 379, a swash plate 381 configured to change position in response to the movement of the solenoids 379, a relief valve 383 for the charge pump 376, a hot oil shuttle 385 hydraulically connected to the charge pump 376, and a dual acting pump 250, as shown in FIG. 9, hydraulically connected to the charge pump 376. The sensors of the pump 250 can be electrically connected to the control package 378 to position the swash plate 381 such that the charge pump 376 is feeding hydraulic fluid to the low side of the loop in order to reciprocate the cylinder assembly 252 within the pump 250 such that pressurized fluid is alternatingly discharged from the first and second pressure tubes 254, 256.
In yet other embodiments of a closed loop circuit, the rodder pump 250 can be used in a de-intensifier circuit wherein the pressure of the hydraulic fluid used to reciprocate the pump 250 is higher than the pressure of the fluid alternately discharged from the first and second pressure chambers. For example, the hydraulic fluid can be at a pressure of about 5 kpsi and the water discharged from the first and second pressure chambers can be at a pressure of about 3 kpsi. In such a situation, a relatively smaller amount of hydraulic fluid can be used than the amount of water that can be discharged from the pump.
In some embodiments of the dual-acting pump, four sensor ports and four corresponding sensors can be provided. Two of the four sensors can be disposed in sensor ports disposed as shown in FIG. 9 to monitor the location of the piston assembly of the cylinder. The other two sensor ports, and accompany ing sensors, can be respectively disposed adjacent the butt fittings 258 such that they detect the presence of the distal end of the first and second plungers, respectively. The third and fourth sensors can detect when the first and second plungers are disposed at the end of their respective discharge stroke and can help to keep the pump in phase. The sensors can also be used to monitor the amount of time it takes for each plunger to travel over its discharge stroke, for example. By disposing the sensors a predetermined amount away from each other, the speed of the plunger can be determined once the time of stroke travel is known. With the pressure tubes being configured to have a predetermined area, the flow rate of fluid from the pump can be computed. This information, along with a cycle count, can be displayed via an LCD, for example, that is electrically connected to the controller.
In yet other embodiments of the pump, the external sensors can be replaced by an inductive sensor system, such as a linear variable differential transformer (LVDT) system or a linear velocity transducer (LVT) system, for example, with the inductive sensor comprising a plurality of coils and a core, one of which being mounted to or comprising the plunger of the cylinder of the pump and the other of which mounted to or comprising a portion of the tube assembly within which the plunger is disposed. The inductive sensor system can include an extension rod made of a non-ferrous material, such as non-magnetic stainless steel, for example. For embodiments having a rodder pump with the dual-acting cylinder, a pair of inductive sensor systems can be provided for each plunger and tube combination.
The inductive sensor can detect the location of the plunger or plungers over the entire stroke of the cylinder and transmit that information to a controller via an electrical connection therewith. The inductive sensor can provide data to the controller relating to the instant position of the cylinder within the tube assembly such that the controller can provide an output of the instantaneous flow rate developed by the pump.
The inductive sensor system can be electrically connected to a controller that is configured to provide a buffered transition when the cylinder changes direction. The controller can be configured to change the flow of hydraulic fluid to the hydraulic ports over a time gradient based on the location of the cylinder as detected by the inductive sensor system such that the velocity of the cylinder gradually decreases until the cylinder changes direction, which also can be detected by the inductive sensor system. Any suitable LVDT system or LVT system can be used as the inductive sensor system with the rodder pump of the present invention.
Referring to FIG. 23, a vehicle 400 for cleaning sewer pipes and/or catch basins is shown. The vehicle 400 can include a debris-collecting dump body 402, a vacuum hose 404 connected thereto, and a vacuum operably connected to the vacuum hose line 404 such that debris can be collected via the vacuum hose 404 and collected in the body 402. The vehicle 400 can also include a multi-stage blower filtration system 406, disposed between the vacuum and the vacuum hose 404, that can act to prevent debris from entering the vacuum blower. The filtration system 406 can include a centrifugal cyclone 408 and a stainless steel screen strainer 410 for filtering debris from the vacuum. The screen strainer 410 can act to remove particles as small as 10 microns, for example. The vacuum hose 404 can be mounted to a hydraulic boom 412 that is pivotally connected to the vehicle chassis. The boom 412 can also be extendable up to a predetermined amount.
The vehicle 400 can also include a cleaning system 420 that comprises a front-mounted hose reel 422 that includes a predetermined length of water hose wound thereon, a control panel 424 disposed adjacent the reel 422 for use by an operator to operate the cleaning system 420, a pair of water tanks 424, respectively disposed on either side of the vehicle 400, a hydraulically driven water pump 426 in fluid communication with the water tanks 424, and a rodder pump 250, as shown in FIG. 9, in fluid communication with the water pump 426 by any suitable water lines. The water lines can connect the butt fittings of the rodder pump to the water pump 426 to allow water to be alternately pumped into the first and second pressure chambers of the rodder pump 250 from the water tanks during the suction stroke of the first and second plungers, respectively. Each of the butt fittings of the pump 250 can also be fluidly connected, via a common feed line, for example, to the length of hose wound on the hose reel 422 such that pressurized water can alternately exit the butt fittings during the discharge stroke of the first and second plungers, respectively. The pressurized water can move through the common feed line to the water hose, and ultimately exit the distal free end of the length of hose. The first and second hydraulic ports of the pump 250 can be hydraulically connected to a hydraulic supply of the vehicle to reciprocally move the cylinder. The distal end of the hose can also support any of a number of tools to facilitate the cleaning of the sewer, such as, a self-propelling jet nozzle, for example. The dual-acting pump 250 can be disposed at the rear end of the vehicle 400. The pump 250 can be arranged in any suitable fluid circuit, such as any described herein above.
The water hose can be unwound from the reel 422 and fed into a sewer, for example. The operator can use the control panel 424 to control the unwinding of the water hose from the reel 422. The operator can activate the water pump and the hydraulic supply such that the water pump operates to pump water to the rodder pump 250 and the hydraulic supply selectively feeds hydraulic fluid to the first and second hydraulic ports of the rodder pump 250 to reciprocally move the dual-acting cylinder to generate pressurized water which, in turn, can be dispensed from the water hose to clean the sewer.
The vehicle 400 can be any suitable vehicle, such as the Vactor® 2100 Series positive displacement sewer cleaner sold by Vactor Manufacturing, Inc. of Streator, Illinois. In yet other embodiments, the pump according to the present invention can be used as part of a water excavator. Other suitable vehicles, and components thereof, are shown and described in U.S. Patent Nos. 3,658,589; RE34,585; and 6,792,646, the entire disclosures thereof being incorporated herein in their entireties by this reference.
Referring to FIG. 24, another embodiment of a rodder pump 550 according to the present invention is shown. The rodder pump 550 includes a dual-acting cylinder 552 and is similar to the rodder pump 250 shown in FIG. 9 and described above. The rodder pump include three tube assemblies 554, 555, 556 that respectively define a first pressure chamber, a hydraulic chamber, and a second pressure chamber. The rodder pump 550 includes first and second blocks 572, 573 disposed at the distal ends of the first and third tube assemblies 554, 556.
Each block 572, 573 includes appropriate valving to allow fluid to alternatingly enter the first and second pressure chambers, respectively, via an inlet port 574. Water can be drawn into a particular pressure chamber when the plunger of the cylinder 552 that is disposed in the particular pressure chamber is undergoing a suction stroke. The inlet ports 574 can be fluidly connected to a vehicle-mounted water pump that is operable to pump water stored in tanks of the vehicle to the rodder pump 550 to provide the supply of fluid to the rodder pump 550.
Each block 572, 573 includes appropriate valving to allow fluid to alternatingly discharge from the first and second pressure chambers, respectively, via an outlet port 575. Water can be discharged from a particular pressure chamber when the plunger of the cylinder 552 that is disposed in the particular pressure chamber is undergoing a discharge stroke. The outlet ports 575 can be fluidly connected to a common feed 576 that is operably connected to a vehicle-mounted water hose line to deliver pressurized water for sewer cleaning applications, for example.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

A rodder pump comprising:

a first tube defining a first pressure chamber;

a second tube defining a hydraulic chamber, the second tube connected to the first tube;

a gland interposed between the first pressure chamber and the hydraulic chamber; and

a cylinder assembly including a piston part and a first plunger, the cylinder assembly reciprocally movable within the first and second tubes;

wherein the piston portion is in sealing contact with the hydraulic chamber and the first plunger is in sealing contact with the gland, the first plunger movable such that the first plunger can extend into the first pressure chamber.
The rodder pump according to claim 1, wherein the second tube includes a first hydraulic port and a second hydraulic port, the first and second hydraulic ports being in fluid communication with the hydraulic chamber, the piston portion being reciprocally movable within the hydraulic chamber, the cylinder assembly being movable in response to a flow of hydraulic fluid through at least one of the first and second hydraulic ports.
The rodder pump according to claim 2, further comprising:

first and second sensors disposed adjacent first and second ends of the hydraulic chamber, the sensors configured to detect when the piston portion is proximal thereto.
The rodder pump according to claim 3, wherein the second tube includes a first and a second sensor port, the sensors respectively disposed in the first and second sensor ports.
The rodder pump according to claim 3, further comprising:

a butt fitting disposed at a distal end of the first tube, the butt fitting having a fluid port in fluid communication with the first pressure chamber.
The rodder pump according to claim 5, wherein the fluid port of the butt fitting has a valve disposed therein, the valve being configured to selectively control the flow of fluid through the fluid port in at least one direction.
The rodder pump according to claim 6, wherein the valve comprises an integrated dual check valve.
The rodder pump according to claim 2, wherein a first fluid port and a second fluid port are in fluid communication with the pressure chamber.
The rodder pump according to claim 2, further comprising:

a third tube defining a second pressure chamber, the third tube connected to the second tube, the second tube disposed between the first and second tubes;

a second gland disposed between the hydraulic chamber and the second pressure chamber;

wherein the cylinder assembly includes a second plunger, the second plunger being in opposing relationship to the first plunger such that the piston part is disposed between the first and second plungers, the cylinder assembly reciprocally movable within the first, second, and third tubes, the second plunger being in sealing contact with the second gland, the second plunger movable such that the second plunger can extend into the second pressure chamber.
The rodder pump according to claim 9, further comprising:

first and second sensors disposed adjacent first and second ends of the hydraulic chamber, the sensors configured to detect when the piston portion is proximal thereto.
The rodder pump according to claim 10, further comprising:

a first butt fitting disposed at a distal end of the first tube, the first butt fitting having a fluid port in fluid communication with the first pressure chamber;

a second butt fitting disposed at a distal end of the third tube, the second butt fitting having a fluid port in fluid communication with the second pressure chamber.
The rodder pump according to claim 11, wherein the fluid port of the first butt fitting has a first valve disposed therein, the first valve being configured to selectively control the flow of fluid through the fluid port in at least one direction.
The rodder pump according to claim 12, wherein the first valve comprises an integrated dual check valve.
The rodder pump according to claim 11, wherein a common feed line connects the fluid port of the first butt fitting and the fluid port of the second butt fitting.
A rodder pump comprising:

a first tube defining a first pressure chamber;

a second tube defining a hydraulic chamber, the second tube sealingly connected to the first tube, the second tube having first and second hydraulic port respectively disposed adjacent first and second ends thereof, the first and second hydraulic ports being in fluid communication with the hydraulic chamber;

a third tube defining a second pressure chamber, the third tube sealingly connected to the second tube, the second tube disposed between the first and second tubes;

a cylinder assembly including a piston part, a first plunger, and a second plunger, the cylinder assembly reciprocally movable within the first, second and third tubes such that the first plunger is reciprocally movable within the first pressure chamber, the piston part is reciprocally movable within the hydraulic chamber, and the second plunger is reciprocally movable within the second pressure chamber;

wherein the cylinder assembly is selectively movable in response to a flow of hydraulic fluid through the first hydraulic port to move the cylinder in a first direction wherein the first plunger moves in a direction from the first pressure chamber toward the hydraulic chamber and through the second hydraulic port to move the cylinder in a second direction wherein the second plunger moves in a direction from the second pressure chamber toward the hydraulic chamber, the second direction opposing the first direction.
A vehicle for cleaning a pipe comprising:

a reel;

a length of hose that is woundable upon the reel;

a water tank for storing a supply of water;

a water pump in fluid communication with the water tank;

a rodder pump, the rodder pump being in fluid communication with the water pump to receive water from the water tank, the rodder pump being in fluid communication with the hose to deliver supply of pressurized water thereto;

a hydraulic supply in hydraulic communication with the rodder pump to selectively operate the rodder pump;

wherein the rodder pump comprises:

a first tube defining a first pressure chamber, the first pressure chamber being in fluid communication with the hose and with the water tank;

a second tube defining a hydraulic chamber, the second tube sealingly connected to the first tube, the hydraulic chamber being in hydraulic communication with the hydraulic supply;

a cylinder assembly including a piston part and a first plunger, the cylinder assembly reciprocally movable within the first and second tubes in response to the flow of the hydraulic fluid in the hydraulic chamber such that the first plunger is reciprocally movable over a suction stroke and a discharge stroke;

wherein water can flow into the first pressure chamber from the water tank during the suction stroke and water can be discharged from the first pressure chamber to the length of hose during the discharge stroke.
The vehicle according to claim 16, further comprising:

a collection body;

a vacuum hose connected to the collection body; and

a vacuum source operably connected to the vacuum hose line such that a vacuum is selectively generated in the vacuum hose to suck debris through the vacuum hose and store in the collection body.
The vehicle according to claim 17, further comprising:

a multi-stage blower filtration system disposed between the vacuum source and the vacuum hose.
The vehicle according to claim 18, wherein the multi-stage blower filtration system includes a centrifugal cyclone and a stainless steel screen strainer for filtering debris from the vacuum source.
The vehicle according to claim 17, further comprising:

a boom mounted on the vehicle, the vacuum hose being supported by the boom.
The vehicle according to claim 20, wherein the boom is extendable over a predetermined range.
The vehicle according to claim 20, wherein the second tube of the rodder pump includes a first hydraulic port and a second hydraulic port, the first and second hydraulic ports being in fluid communication with the hydraulic chamber and with the hydraulic supply, the piston portion being reciprocally movable within the hydraulic chamber, the cylinder assembly being selectively movable in response to the flow of hydraulic fluid through the first hydraulic port to move the cylinder in a first direction and through the second hydraulic port to move the cylinder in a second direction, the second direction opposing the first direction.
The vehicle according to claim 22, wherein the rodder pump further comprises a third tube defining a second pressure chamber, the third tube sealingly connected to the second tube, and the cylinder assembly includes a second plunger, the second plunger movable such that the second plunger can extend into the second pressure chamber, the second pressure chamber being in fluid communication with the water tank and the length of hose, the second plunger being reciprocally movable over a suction stroke and a discharge stroke, the second plunger arranged with the second pressure chamber such that water can flow into the second pressure chamber from the water tank during the suction stroke of the second plunger and water can be discharged from the second pressure chamber to the length of hose during the discharge stroke of the second plunger.
The vehicle according to claim 23, wherein the suction stroke and the discharge stroke of the first plunger are in alternating relationship to the suction stroke and the discharge stroke of the second plunger such that when the first plunger is undergoing the suction stroke, the second plunger is undergoing the discharge stroke.
The vehicle according to claim 24, wherein the first pressure chamber and the second pressure chamber are in fluid communication with each other via a common feed line such that water is alternatingly discharged from the first and second pressure chambers into the common feed line during the respective discharge strokes of the first and second plungers, the common feed line being in fluid communication with the length of hose.