CA2493340A1 - Control system for reciprocating drive - Google Patents
Control system for reciprocating drive Download PDFInfo
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- CA2493340A1 CA2493340A1 CA 2493340 CA2493340A CA2493340A1 CA 2493340 A1 CA2493340 A1 CA 2493340A1 CA 2493340 CA2493340 CA 2493340 CA 2493340 A CA2493340 A CA 2493340A CA 2493340 A1 CA2493340 A1 CA 2493340A1
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- Prior art keywords
- gas
- piston
- radial port
- fluid communication
- port
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- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
- F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
- F04B9/12—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air
- F04B9/123—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber
- F04B9/125—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber reciprocating movement of the pumping member being obtained by a double-acting elastic-fluid motor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L25/00—Drive, or adjustment during the operation, or distribution or expansion valves by non-mechanical means
- F01L25/02—Drive, or adjustment during the operation, or distribution or expansion valves by non-mechanical means by fluid means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L29/00—Reversing-gear
- F01L29/06—Reversing-gear by interchanging inlet and exhaust ports
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
- F01L2003/25—Valve configurations in relation to engine
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
A control system for a reciprocating drive having a shaft which is reciprocally moved by the control system solely by gas acting against a piston. The control system includes a gas manifold having a first mode and a second mode. In the first mode, gas is supplied on a first side of the piston to cause the piston to move in a first direction and gas is exhausted on a second side of the piston. In the second mode, gas is supplied to the second side of the piston to cause the piston to move in the second direction and gas is exhausted on the first side of the piston.
Description
TITLE OF THE INVENTION:
Control System for reciprocating drive FIELD OF THE INVENTION
The present invention relates to a control system for a reciprocating drive for use in such applications as reciprocating actuators, reciprocating power generators, and reciprocating pumps commonly used for chemical injection on gas producing wells.
BACKGROUND OF THE INVENTION
United States Patent 6,263,777 (Lauder 2001) entitled "Control System for reciprocating device", describes a problem currently being experienced with reciprocating pumps. At low speeds of operation at low pressure, the reciprocating pump can become stuck. The control system described in the Lauder reference includes a reciprocating device that moves in a first direction due to fluid pressure and in a second direction due to a spring, when pressure is reduced. A trigger on the reciprocating device engages a connector, which has a spring. The spring is compressed, storing energy as the reciprocating device moves in the second direction. This stored energy is used to assist in moving a toggle switch through a middle position, where it might otherwise become stuck, during movement in the first direction.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a control system for a reciprocating drive. The drive has a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction. The reciprocating shaft 2 5 has a first end and a second end. A piston is mounted at the first end of the shaft. The piston has a first side and a second side. A fluid retaining piston chamber houses the piston. The piston chamber has a first side fluid communication port on the first side of the piston and a second side fluid communication port on the second side of the piston. The second end of the shaft serves an intended function as it reciprocates. The control system includes a gas 3 0 manifold having a gas inlet adapted for connection to a gas source supplying gas to the gas manifold and a gas exhaust adapted to exhaust gas from the gas manifold. Means are provided for configuring the gas manifold in a first mode, with the gas inlet connected to the first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction. The second side fluid communication port concurrently is connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction.
Means are also provided for configuring the gas manifold in a second mode, with the gas inlet connected to the second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction. The first side fluid communication port concurrently is connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction.
Means are provided for switching between the first mode and the second mode, such that the shaft of the drive is reciprocated solely by gas pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:
FIG. 1 is a top plan view, in section, of a control system constructed in accordance 2 0 with the teachings of the present invention, with the control system in the first mode.
FIG. 2 is a top plan view, in section, of the control system illustrated in FIG.1, with the control system in the second mode.
FIG. 3 is a detailed side elevation view of a trigger mechanism from the control system illustrated in FIG.1.
2 5 FIG. 4a through 4g are a series of detailed side elevation views of the trigger mechanism illustrated in FIG. 3, showing movement of through an activation sequence.
FIG. 5 is a detailed side elevation view of a cylindrical seal carrier for the control system illustrated in FIG.1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a control system for a reciprocating drive will now be described with reference to FIG. 1 through 5. A chemical injection application has been chosen for purposes of illustration. It will be appreciated, however, that the described control system can be used for an infinite variety of other reciprocating applications.
Structure and Relationship of Parts:
Referring to FIG. 1 and FIG. 2, there is provided a drive, generally indicated by reference numeral 10 and a control system for that drive, generally indicated by reference numeral 12. Most reciprocating drives require a minimum gas pressure of approximately 30 pounds per square inch (psi.) in order to operate. Below that pressure, they tend to flutter and stall. As gas wells age, they experience a decrease in pressure. An increasing number of gas wells are incapable of providing 30 psi pressure. Efforts were, therefore made when developing control system 12 and reciprocating drive 10, to have them capable of operating together at pressures of 10 psi or less. There will now be described how this was accomplished. Of course, drive 10 and control system 12 are still capable of operating at pressures greater than 10 psi.
Referring to FIG. 1 and FIG. 2, drive 10 has a reciprocating shaft 14.
Referring to FIG.1, shaft 14 reciprocally moves in a first direction, as indicated by arrow 16. Referring to FIG. 2, shaft reciprocally moves in a second direction, (opposed to the first direction), as 2 0 indicated by arrow 18. Referring to FIG. 1 and FIG. 2, reciprocating shaft 14 has a first end and a second end 22. A piston 24 is mounted at first end 20 of shaft 14.
Piston 24 has a first side 26 and a second side 28. A fluid retaining piston chamber 30 houses piston 24.
Piston chamber 30 has a first side fluid communication port 32 positioned on first side 26 of piston 24 and a second side fluid communication port 34 positioned on second side 28 of 2 5 piston 24. There may be than one first side fluid communication port and more than one second side fluid communication port, if the intake and exhaust functions are separated. As will hereinafter be further described, in the preferred embodiment the intake and exhaust functions are integrated with the same fluid communication port used for both functions.
Second end 22 of shaft 14 is connected to a displacement rod 23 which is adapted to control 3 0 flow from a chemical source (not shown). The type of device which is being controlled by movement of second end 22 of shaft 14 is not critical to the present invention. There is illustrated one possible configuration of chemical injector showing a fluid conduit 36.
Control System for reciprocating drive FIELD OF THE INVENTION
The present invention relates to a control system for a reciprocating drive for use in such applications as reciprocating actuators, reciprocating power generators, and reciprocating pumps commonly used for chemical injection on gas producing wells.
BACKGROUND OF THE INVENTION
United States Patent 6,263,777 (Lauder 2001) entitled "Control System for reciprocating device", describes a problem currently being experienced with reciprocating pumps. At low speeds of operation at low pressure, the reciprocating pump can become stuck. The control system described in the Lauder reference includes a reciprocating device that moves in a first direction due to fluid pressure and in a second direction due to a spring, when pressure is reduced. A trigger on the reciprocating device engages a connector, which has a spring. The spring is compressed, storing energy as the reciprocating device moves in the second direction. This stored energy is used to assist in moving a toggle switch through a middle position, where it might otherwise become stuck, during movement in the first direction.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a control system for a reciprocating drive. The drive has a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction. The reciprocating shaft 2 5 has a first end and a second end. A piston is mounted at the first end of the shaft. The piston has a first side and a second side. A fluid retaining piston chamber houses the piston. The piston chamber has a first side fluid communication port on the first side of the piston and a second side fluid communication port on the second side of the piston. The second end of the shaft serves an intended function as it reciprocates. The control system includes a gas 3 0 manifold having a gas inlet adapted for connection to a gas source supplying gas to the gas manifold and a gas exhaust adapted to exhaust gas from the gas manifold. Means are provided for configuring the gas manifold in a first mode, with the gas inlet connected to the first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction. The second side fluid communication port concurrently is connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction.
Means are also provided for configuring the gas manifold in a second mode, with the gas inlet connected to the second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction. The first side fluid communication port concurrently is connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction.
Means are provided for switching between the first mode and the second mode, such that the shaft of the drive is reciprocated solely by gas pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:
FIG. 1 is a top plan view, in section, of a control system constructed in accordance 2 0 with the teachings of the present invention, with the control system in the first mode.
FIG. 2 is a top plan view, in section, of the control system illustrated in FIG.1, with the control system in the second mode.
FIG. 3 is a detailed side elevation view of a trigger mechanism from the control system illustrated in FIG.1.
2 5 FIG. 4a through 4g are a series of detailed side elevation views of the trigger mechanism illustrated in FIG. 3, showing movement of through an activation sequence.
FIG. 5 is a detailed side elevation view of a cylindrical seal carrier for the control system illustrated in FIG.1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a control system for a reciprocating drive will now be described with reference to FIG. 1 through 5. A chemical injection application has been chosen for purposes of illustration. It will be appreciated, however, that the described control system can be used for an infinite variety of other reciprocating applications.
Structure and Relationship of Parts:
Referring to FIG. 1 and FIG. 2, there is provided a drive, generally indicated by reference numeral 10 and a control system for that drive, generally indicated by reference numeral 12. Most reciprocating drives require a minimum gas pressure of approximately 30 pounds per square inch (psi.) in order to operate. Below that pressure, they tend to flutter and stall. As gas wells age, they experience a decrease in pressure. An increasing number of gas wells are incapable of providing 30 psi pressure. Efforts were, therefore made when developing control system 12 and reciprocating drive 10, to have them capable of operating together at pressures of 10 psi or less. There will now be described how this was accomplished. Of course, drive 10 and control system 12 are still capable of operating at pressures greater than 10 psi.
Referring to FIG. 1 and FIG. 2, drive 10 has a reciprocating shaft 14.
Referring to FIG.1, shaft 14 reciprocally moves in a first direction, as indicated by arrow 16. Referring to FIG. 2, shaft reciprocally moves in a second direction, (opposed to the first direction), as 2 0 indicated by arrow 18. Referring to FIG. 1 and FIG. 2, reciprocating shaft 14 has a first end and a second end 22. A piston 24 is mounted at first end 20 of shaft 14.
Piston 24 has a first side 26 and a second side 28. A fluid retaining piston chamber 30 houses piston 24.
Piston chamber 30 has a first side fluid communication port 32 positioned on first side 26 of piston 24 and a second side fluid communication port 34 positioned on second side 28 of 2 5 piston 24. There may be than one first side fluid communication port and more than one second side fluid communication port, if the intake and exhaust functions are separated. As will hereinafter be further described, in the preferred embodiment the intake and exhaust functions are integrated with the same fluid communication port used for both functions.
Second end 22 of shaft 14 is connected to a displacement rod 23 which is adapted to control 3 0 flow from a chemical source (not shown). The type of device which is being controlled by movement of second end 22 of shaft 14 is not critical to the present invention. There is illustrated one possible configuration of chemical injector showing a fluid conduit 36.
Displacement rod 23, which is connected to second end 22 of shaft 14, acts as a plunger capable of extending transversely across fluid conduit 36 between two one way valves 38 and 40, which only permit a flow in a direction indicated by arrow 42. When shaft 14 moves reciprocally in the second direction indicated by arrow 18, displacement rod 23 is withdrawn and chemicals can flow freely along fluid conduit 36. When shaft 14 moves in the first direction indicated by arrow 16, displacement rod 23 becomes positioned across fluid conduit 36 and the flow of chemical is blocked. An annular seal, generally indicated by reference numeral 44, is positioned around displacement rod 23 to prevent the incursion of chemicals from the chemical source into drive 10.
Referring to FIG. 1 and FIG. 2, control system 12 includes a gas manifold 46.
A gas inlet 48 is provided which is adapted for connection to a gas source (not shown) supplying gas to gas manifold 46. A gas exhaust 50 is provided which is adapted to exhaust gas from gas manifold 46. Gas manifold has a first mode, which is illustrated in FIG. 1 and a second mode, which is illustrated in FIG. 2. Referring to FIG. 1, in the first mode, gas inlet 48 is connected to first side fluid communication port 32 to supply gas to piston chamber 30 on first side 26 of piston 24 to cause piston 24 to move in the first direction, as indicated by arrow 16. Second side fluid communication port 34 is concurrently connected to gas exhaust 50, to exhaust gas from piston chamber 30 on second side 28 of piston 24 as piston 24 moves 2 0 in the first direction. Referring to FIG. 2, in the second mode, gas inlet 48 is connected to second side fluid communication port 34 to supply gas to piston chamber 30 on second side 28 of piston 24 to cause piston 24 to move in a second direction, as indicated by arrow 18.
The first side fluid communication port 32 is concurrently connected to gas exhaust 50 to exhaust gas from piston chamber 30 on first side 26 of piston 24 as piston 24 moves in the 2 5 second direction. A switch, generally indicated by reference numeral 52 is used as means for switching between the first mode illustrated in FIG. 1 and the second mode, illustrated in FIG. 2. It is to be noted that with control system 12, shaft 14 of drive 10 is reciprocated solely by gas pressure. Prior art control systems used a spring to bias shaft 14 is one direction. This meant that sufficient gas pressure had to be provided to overcome the biasing 3 0 force of the spring return for shaft 14. By having control system 12 operated solely by gas pressure, control system 12 is able to operate at lower levels of gas pressure.
The operation of gas manifold 46 will now be described in greater detail.
Referring to FIG. 1 and FIG. 2, gas manifold 46 consists of a barrel 54, which has been extended through the use of a first fitting 55 positioned at a first end 56 and a second fitting 57 positioned at a second end 58. For the purpose of this description, the extensions provided by first fitting 55 5 and second fitting 57 will be considered part of barrel 54. Gas inlet 48 is positioned at first end 56. A gas control valve 49 is position upstream of gas inlet 48. Barrel 54 has a series of radial ports, a first radial port 59, a second radial port 60, a third radial port 62, a fourth radial port 64, and a fifth radial port 66. These radial ports are sequentially spaced at spaced intervals along barrel 54 from first end 56 to second end 58. Second radial port 60 is connected to second side fluid communication port 34, so it is always in fluid communication with second side 28 of piston 24. Third radial port 62 is connected to gas exhaust 50. Fourth radial port 64 is connected to first side fluid communication port 32, so it is always in fluid communication with first side 26 of piston 24. First radial port 59 is connected to fifth radial port 66, which connection plays a role in switching, as will be hereinafter further explained.
Switch 52 has a first member 68 and a second member 70, that move axially in barrel 54 to effect a change in the relationship between the radial ports.
Referring to FIG. 1, in the first mode, first member 68 of switch 52 is positioned between first radial port 59 and second radial port 60. Second member 70 of switch 52 is 2 0 positioned between third radial port 62 and fourth radial port 64. Gas supplied through gas inlet 48 flows into barrel 54 where it encounters first member 68. The only place the gas can go is to pass out through first radial port 59, re-entering barrel 54 at fifth radial port 66. Gas entering barrel 54 through fifth radial port 66 encounters second member 70.
The only place that the gas can go is to pass out fourth radial port 64 leading to first side fluid communication 2 5 port 32 and into piston chamber 30. Once in piston chamber 30, the in flowing gas creates pressure on first side 26 of piston 24, causing piston 24 to move in the first direction, as indicated by arrow 16. This movement of piston 24 in the first direction, forces gas out of piston chamber 30 through second side fluid communication port 34. The exhaust gas enters into barrel 54 through second radial port 60. Once within barrel 54, the exhaust gas is 3 0 confined between first member 68 and second member 70. The only place the exhaust gas can go is to pass out third radial port 62 to gas exhaust 50.
Referring to FIG. 1 and FIG. 2, control system 12 includes a gas manifold 46.
A gas inlet 48 is provided which is adapted for connection to a gas source (not shown) supplying gas to gas manifold 46. A gas exhaust 50 is provided which is adapted to exhaust gas from gas manifold 46. Gas manifold has a first mode, which is illustrated in FIG. 1 and a second mode, which is illustrated in FIG. 2. Referring to FIG. 1, in the first mode, gas inlet 48 is connected to first side fluid communication port 32 to supply gas to piston chamber 30 on first side 26 of piston 24 to cause piston 24 to move in the first direction, as indicated by arrow 16. Second side fluid communication port 34 is concurrently connected to gas exhaust 50, to exhaust gas from piston chamber 30 on second side 28 of piston 24 as piston 24 moves 2 0 in the first direction. Referring to FIG. 2, in the second mode, gas inlet 48 is connected to second side fluid communication port 34 to supply gas to piston chamber 30 on second side 28 of piston 24 to cause piston 24 to move in a second direction, as indicated by arrow 18.
The first side fluid communication port 32 is concurrently connected to gas exhaust 50 to exhaust gas from piston chamber 30 on first side 26 of piston 24 as piston 24 moves in the 2 5 second direction. A switch, generally indicated by reference numeral 52 is used as means for switching between the first mode illustrated in FIG. 1 and the second mode, illustrated in FIG. 2. It is to be noted that with control system 12, shaft 14 of drive 10 is reciprocated solely by gas pressure. Prior art control systems used a spring to bias shaft 14 is one direction. This meant that sufficient gas pressure had to be provided to overcome the biasing 3 0 force of the spring return for shaft 14. By having control system 12 operated solely by gas pressure, control system 12 is able to operate at lower levels of gas pressure.
The operation of gas manifold 46 will now be described in greater detail.
Referring to FIG. 1 and FIG. 2, gas manifold 46 consists of a barrel 54, which has been extended through the use of a first fitting 55 positioned at a first end 56 and a second fitting 57 positioned at a second end 58. For the purpose of this description, the extensions provided by first fitting 55 5 and second fitting 57 will be considered part of barrel 54. Gas inlet 48 is positioned at first end 56. A gas control valve 49 is position upstream of gas inlet 48. Barrel 54 has a series of radial ports, a first radial port 59, a second radial port 60, a third radial port 62, a fourth radial port 64, and a fifth radial port 66. These radial ports are sequentially spaced at spaced intervals along barrel 54 from first end 56 to second end 58. Second radial port 60 is connected to second side fluid communication port 34, so it is always in fluid communication with second side 28 of piston 24. Third radial port 62 is connected to gas exhaust 50. Fourth radial port 64 is connected to first side fluid communication port 32, so it is always in fluid communication with first side 26 of piston 24. First radial port 59 is connected to fifth radial port 66, which connection plays a role in switching, as will be hereinafter further explained.
Switch 52 has a first member 68 and a second member 70, that move axially in barrel 54 to effect a change in the relationship between the radial ports.
Referring to FIG. 1, in the first mode, first member 68 of switch 52 is positioned between first radial port 59 and second radial port 60. Second member 70 of switch 52 is 2 0 positioned between third radial port 62 and fourth radial port 64. Gas supplied through gas inlet 48 flows into barrel 54 where it encounters first member 68. The only place the gas can go is to pass out through first radial port 59, re-entering barrel 54 at fifth radial port 66. Gas entering barrel 54 through fifth radial port 66 encounters second member 70.
The only place that the gas can go is to pass out fourth radial port 64 leading to first side fluid communication 2 5 port 32 and into piston chamber 30. Once in piston chamber 30, the in flowing gas creates pressure on first side 26 of piston 24, causing piston 24 to move in the first direction, as indicated by arrow 16. This movement of piston 24 in the first direction, forces gas out of piston chamber 30 through second side fluid communication port 34. The exhaust gas enters into barrel 54 through second radial port 60. Once within barrel 54, the exhaust gas is 3 0 confined between first member 68 and second member 70. The only place the exhaust gas can go is to pass out third radial port 62 to gas exhaust 50.
Referring to FIG. 2, in the second mode, first member 68 of switch 52 is positioned beriveen second radial port 60 and third radial port 62. Second member 70 of switch 52 is positioned between fourth radial port 64 and fifth radial port 66. Gas supplied through gas inlet 48 flowing into barrel encounters first member 68 and concurrently passes out first radial port 59 and second radial port 60. Gas flowing out of first radial port 59 re-enters barrel 54 through fifth radial port 66, where it encounters a dead end in barrel 54 created by the positioning of second member 70. Gas flowing out of second radial port 60 passes through second side fluid communication port 34 into piston chamber 30 on second side 28 of piston 24. The pressure exerted by the inflowing gas causes piston 24 to move in the second direction, as indicated by arrow 18. The movement of piston 30 in the second direction, forces exhaust gas out of piston chamber 30 through first side fluid communication port 32 and into barrel 54 through fourth radial port 64. Exhaust gas in barrel 54 is confined between first member 68 and second member 70. The only place the exhaust gas can go is to exit out of third radial port 62 to gas exhaust 50.
Switch 52 is what is termed a "four way two position snap switch". Switch 52 has a switch lever 72. Switch lever 72 is activated when reciprocating shaft 14 moves in the first direction by a first trigger mechanism 74, which is carried by reciprocating shaft 14.
Conversely, switch lever 72 is activated when reciprocating shaft 14 moves in the second 2 0 direction by a second trigger mechanism 76 carried by reciprocating shaft 14. Drive 10 and control system I2 has been operated at speeds as low as one stroke every three minutes. This is an incredibly slow speed, compared to the prior art. In order to facilitate such a slow speed, without fluttering or stalling, first trigger mechanism 74 and second trigger mechanism 76 are of unique construction. Referring to FIG. 3, each trigger mechanism includes a spring 78, 2 5 which is coiled around a sleeve 79, which slides over reciprocating shaft 14. Spring 78 has a fixed end 80 and a free end 82. A stop 84 engages fixed end 80 of spring 78 to prevent axial movement of spring 78 along reciprocating shaft 14. In the illustrated embodiment, stop 84 consists of a collar 86 on sleeve 79. A set screw 88 extends through collar 86 to secure sleeve 79 to reciprocating shaft 14. Set screw 88 facilitates the selective positioning of the trigger 3 0 mechanism along reciprocating shaft 14, which determines stroke length. A
trigger member 90 is biased by free end 82 of spring 78. In the illustrated embodiment, trigger member 90 is an annular pivot ring 92 having a central aperture 94. Sleeve 79 extends through central aperture 94. A second stop 96 is the form of a snap ring retainer. This second stop 96 is adapted to limit axial movement of trigger member 90 along sleeve 79 and prevents trigger member 90 from separating from sleeve 79. The functioning of the trigger mechanism can best be understood by following the sequential order of FIG. 4a through 4g.
Referring to FIG. 5, annular seal 44 includes a housing 98 having an interior sidewall 100 defining a cylindrical seal chamber 102. In the prior art, seal chamber was filled with chevron packing (also known as "V" packing). This chevron packing exerted considerable friction upon displacement rod 23, for the length of housing 98. In order to reduce friction, a different form of sealing has been used, while leaving the structure of housing 98 substantially the same. A cylindrical seal carrier 104 is provided which is adapted to fit within cylindrical seal chamber 102. Seal carrier 104 has an exterior surface 106 and an interior surface 108.
Interior surface 108 serves to define a central bore 110, which is adapted to receive displacement rod 23. An exterior circumferential seal groove I 12 is provided on exterior surface 106 of seal carrier 104. Two interior circumferential seal grooves 114, one at each end, are provided on interior surface 108 of seal carrier 104. An exterior seal ring 116 positioned in exterior circumferential seal groove 112 and is adapted to from a seal between exterior surface 106 of seal carrier 104 and interior sidewall 100 of housing 98. An interior seal ring 118 is positioned in each interior circumferential seal groove 114.
Each interior seal 2 0 ring 118 is adapted to from a seal between interior surface 108 of seal carrier 104 and displacement rod 23. Housing 98 has an end cap 120, which closes seal chamber 102. End cap 120 is removed to provide access to seal chamber 102 to permit the insertion and removal of seal carrier 104. When chevron packing is used, a pressure member 122 is used to exert a compressive force upon the chevron packing. As the packing wears, end cap 120 is tightened 2 5 to apply more pressure upon the chevron packing, via pressure member 122.
Annular seal 44 is shown as having a pressure member 122. When used with seal carrier 104, pressure member 122 merely serves to hold seal carrier 104 securely in place so there is no axial movement in housing 98. Where pressures exceed 100 p.s.i., the use of chevron packing is still recommended. However, where pressures are under 100 p.s.i., the sealing system 3 0 illustrated is preferred.
Installation and Operation:
Switch 52 is what is termed a "four way two position snap switch". Switch 52 has a switch lever 72. Switch lever 72 is activated when reciprocating shaft 14 moves in the first direction by a first trigger mechanism 74, which is carried by reciprocating shaft 14.
Conversely, switch lever 72 is activated when reciprocating shaft 14 moves in the second 2 0 direction by a second trigger mechanism 76 carried by reciprocating shaft 14. Drive 10 and control system I2 has been operated at speeds as low as one stroke every three minutes. This is an incredibly slow speed, compared to the prior art. In order to facilitate such a slow speed, without fluttering or stalling, first trigger mechanism 74 and second trigger mechanism 76 are of unique construction. Referring to FIG. 3, each trigger mechanism includes a spring 78, 2 5 which is coiled around a sleeve 79, which slides over reciprocating shaft 14. Spring 78 has a fixed end 80 and a free end 82. A stop 84 engages fixed end 80 of spring 78 to prevent axial movement of spring 78 along reciprocating shaft 14. In the illustrated embodiment, stop 84 consists of a collar 86 on sleeve 79. A set screw 88 extends through collar 86 to secure sleeve 79 to reciprocating shaft 14. Set screw 88 facilitates the selective positioning of the trigger 3 0 mechanism along reciprocating shaft 14, which determines stroke length. A
trigger member 90 is biased by free end 82 of spring 78. In the illustrated embodiment, trigger member 90 is an annular pivot ring 92 having a central aperture 94. Sleeve 79 extends through central aperture 94. A second stop 96 is the form of a snap ring retainer. This second stop 96 is adapted to limit axial movement of trigger member 90 along sleeve 79 and prevents trigger member 90 from separating from sleeve 79. The functioning of the trigger mechanism can best be understood by following the sequential order of FIG. 4a through 4g.
Referring to FIG. 5, annular seal 44 includes a housing 98 having an interior sidewall 100 defining a cylindrical seal chamber 102. In the prior art, seal chamber was filled with chevron packing (also known as "V" packing). This chevron packing exerted considerable friction upon displacement rod 23, for the length of housing 98. In order to reduce friction, a different form of sealing has been used, while leaving the structure of housing 98 substantially the same. A cylindrical seal carrier 104 is provided which is adapted to fit within cylindrical seal chamber 102. Seal carrier 104 has an exterior surface 106 and an interior surface 108.
Interior surface 108 serves to define a central bore 110, which is adapted to receive displacement rod 23. An exterior circumferential seal groove I 12 is provided on exterior surface 106 of seal carrier 104. Two interior circumferential seal grooves 114, one at each end, are provided on interior surface 108 of seal carrier 104. An exterior seal ring 116 positioned in exterior circumferential seal groove 112 and is adapted to from a seal between exterior surface 106 of seal carrier 104 and interior sidewall 100 of housing 98. An interior seal ring 118 is positioned in each interior circumferential seal groove 114.
Each interior seal 2 0 ring 118 is adapted to from a seal between interior surface 108 of seal carrier 104 and displacement rod 23. Housing 98 has an end cap 120, which closes seal chamber 102. End cap 120 is removed to provide access to seal chamber 102 to permit the insertion and removal of seal carrier 104. When chevron packing is used, a pressure member 122 is used to exert a compressive force upon the chevron packing. As the packing wears, end cap 120 is tightened 2 5 to apply more pressure upon the chevron packing, via pressure member 122.
Annular seal 44 is shown as having a pressure member 122. When used with seal carrier 104, pressure member 122 merely serves to hold seal carrier 104 securely in place so there is no axial movement in housing 98. Where pressures exceed 100 p.s.i., the use of chevron packing is still recommended. However, where pressures are under 100 p.s.i., the sealing system 3 0 illustrated is preferred.
Installation and Operation:
Installation and operation will now be described with reference to FIG. 1 through FIG. 5, in order to obtain the benefits of all aspects of the present invention. Referring to FIG. 1 and FIG. 2, when assembling drive 10, sleeves 79 of first trigger mechanism 74 and second trigger mechanism 76 are placed over reciprocating shaft 14. Referring to FIG. 3, set screw 88 is then used to secure sleeves 79 at the desired locations along reciprocating shaft 14. It must be noted that central aperture 94 of pivot ring 92 must be larger than the diameter of sleeve 79 to allow movement of pivot ring 92, while being smaller than the outside diameter of spring 78 in order to be biased by spring 78. Referring to FIG. 1 and FIG. 2, gas manifold 46 is connected to drive 10. Second radial port 60 is connected to second side fluid communication port 34, so it is always in fluid communication with second side 28 of piston 24. Third radial port 62 is connected to gas exhaust 50. Fourth radial port 64 is connected to first side fluid communication port 32, so it is always in fluid communication with first side 26 of piston 24. Gas inlet 48 is connected to a gas source. Seal carrier 104 is inserted into annular seal 44 in place of chevron packing, where the operating pressures are low enough to warrant such a substitution.
Referring to FIG. 1, operation of drive 10 begins in the first mode, with first member 68 of switch 52 positioned between first radial port 59 and second radial port 60 and second member 70 positioned between third radial port 62 and fourth radial port 64.
Gas supplied 2 0 through gas inlet 48 flows into barrel 54 where it encounters first member 68. Gas passes out through ftrst radial port 59, re-entering barrel 54 at fifth radial port 66.
Gas entering barrel 54 through f fth radial port 66 encounters second member 70. Gas passes out fourth radial port 64 leading to first side fluid communication port 32 and into piston chamber 30. Once in piston chamber 30, the in flowing gas creates pressure on first side 26 of piston 24, causing 2 5 piston 24 to move in the first direction, as indicated by arrow 16. This movement of piston 24 in the first direction, forces gas out of piston chamber 30 through second side fluid communication port 34. The exhaust gas enters into barrel 54 through second radial port 60.
Once within barrel 54, the exhaust gas is confined between first member 68 and second member 70. Gas then passes out third radial port 62 to gas exhaust 50.
Referring to FIG. 4a through 4g, the operation of first trigger mechanism 74 is sequentially illustrated. Referring to FIG. 4a, movement of reciprocating shaft 14 carries first trigger mechanism 74 toward switch lever 72 of switch 52. Referring to FIG.
4b, as reciprocating shaft 14, pivot ring 92 comes into contact with switch lever 72.
Refernng to FIG. 4c, upon continuing movement pivot ring 92 will start to tilt backwards, with such movement being resisted by spring 78. As reciprocating shaft 14 continues to move, spring 78 becoming increasingly compressed, which creates an increasing preload by first trigger mechanism 74 upon switch lever 72. Referring to FIG. 4d, eventually there is enough stored energy to cause switch lever 72 to start to change direction. Referring to FIG. 4e, the movement of switch lever 72 is rapid and deliberate. This rapid and deliberate movement is the result of three forces: the forward momentum of reciprocating shaft 14, the release of spring tension from spring 78, and the inherent snap acting characteristics of switch lever 72.
Referring to FIG. 4f, once switch lever 72 has changed position the momentum of reciprocating shaft 14 slows in preparation for movement in the second direction. Referring to FIG. 4g, first trigger mechanism 74 then moves away from switch lever 72 as a change in direction occurs and second trigger mechanism 76 will approach switch lever 72 from the opposite direction. The operation of second trigger mechanism 76, upon movement in the opposite direction is identical and will, therefore, not be further described.
Referring to FIG. 2, when switch lever 72 is switched to the second mode, first member 68 of switch 52 is positioned between second radial port 60 and third radial port 62 2 0 and second member 70 is positioned between fourth radial port 64 and fifth radial port 66.
Gas continues to be supplied through gas inlet 48 flowing into barrel, however now as it encounters first member 68 it concurrently passes out first radial port 59 and second radial port 60. Gas flowing out of first radial port 59 re-enters barrel 54 through fifth radial port 66, where it encounters a dead end in barrel 54 created by the positioning of second member 70.
2 5 Gas flowing out of second radial port 60 passes through second side fluid communication port 34 into piston chamber 30 on second side 28 of piston 24. The pressure exerted by the in flowing gas causes piston 24 to move in the second direction, as indicated by arrow 18. The movement of piston 30 in the second direction, forces exhaust gas out of piston chamber 30 through first side fluid communication port 32 and into barrel 54 through fourth radial port 3 0 64. Exhaust gas in barrel 54 is confined between first member 68 and second member 70.
The exhaust gas then exits out of third radial port 62 to gas exhaust 50.
Referring to FIG. 1 and FIG. 2, when drive 10 is operated with control system 12, considerably less gas is used. The reason for this is that all of the gas supplied is used to power piston 24, as opposed to other systems in which gas at higher pressures was required to overcome the biasing force of a return spring for the reciprocating shaft.
There are some 5 systems which operate by having a constant bleed of gas through poppet valves. Control system has a much lower gas consumption than such systems and is, therefore, a more environmentally responsible system. Referring to FIG. 4a through 4g, the use of trigger mechanisms 74 and 76, help further facilitated slow, low pressure operation.
What is meant by slow is speeds as low as one stroke every three minutes. What is meant by low pressure is 10 pressure in a range of 7 to 10 psi. Referring to FIG. 5, the use of seal carrier 104 in place of chevron packing, assists further in reaching this objective of slow, low pressure operation, by reducing overall friction and resistance considerably. It also serves a secondary function of maintaining displacement rod 23 centred in housing 98. It is preferred that grease be packed into central bore 110 between interior seal rings 118 at the time of insertion of displacement rod 23. This gives annular seal 44 a self lubrication quality and further reduces friction as the grease will move between interior seal rings 118, during reciprocating movement. Referring to FIG.1 and FIG. 2, it will be understood that the speed of the unit is ultimately determined by gas control valve 49 position upstream of gas inlet 48. The stroke of reciprocating shaft 14 is set by the positioning of first trigger mechanism 74 and second trigger mechanism 76.
In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the 2 5 possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as 3 0 hereinafter defined in the Claims.
Referring to FIG. 1, operation of drive 10 begins in the first mode, with first member 68 of switch 52 positioned between first radial port 59 and second radial port 60 and second member 70 positioned between third radial port 62 and fourth radial port 64.
Gas supplied 2 0 through gas inlet 48 flows into barrel 54 where it encounters first member 68. Gas passes out through ftrst radial port 59, re-entering barrel 54 at fifth radial port 66.
Gas entering barrel 54 through f fth radial port 66 encounters second member 70. Gas passes out fourth radial port 64 leading to first side fluid communication port 32 and into piston chamber 30. Once in piston chamber 30, the in flowing gas creates pressure on first side 26 of piston 24, causing 2 5 piston 24 to move in the first direction, as indicated by arrow 16. This movement of piston 24 in the first direction, forces gas out of piston chamber 30 through second side fluid communication port 34. The exhaust gas enters into barrel 54 through second radial port 60.
Once within barrel 54, the exhaust gas is confined between first member 68 and second member 70. Gas then passes out third radial port 62 to gas exhaust 50.
Referring to FIG. 4a through 4g, the operation of first trigger mechanism 74 is sequentially illustrated. Referring to FIG. 4a, movement of reciprocating shaft 14 carries first trigger mechanism 74 toward switch lever 72 of switch 52. Referring to FIG.
4b, as reciprocating shaft 14, pivot ring 92 comes into contact with switch lever 72.
Refernng to FIG. 4c, upon continuing movement pivot ring 92 will start to tilt backwards, with such movement being resisted by spring 78. As reciprocating shaft 14 continues to move, spring 78 becoming increasingly compressed, which creates an increasing preload by first trigger mechanism 74 upon switch lever 72. Referring to FIG. 4d, eventually there is enough stored energy to cause switch lever 72 to start to change direction. Referring to FIG. 4e, the movement of switch lever 72 is rapid and deliberate. This rapid and deliberate movement is the result of three forces: the forward momentum of reciprocating shaft 14, the release of spring tension from spring 78, and the inherent snap acting characteristics of switch lever 72.
Referring to FIG. 4f, once switch lever 72 has changed position the momentum of reciprocating shaft 14 slows in preparation for movement in the second direction. Referring to FIG. 4g, first trigger mechanism 74 then moves away from switch lever 72 as a change in direction occurs and second trigger mechanism 76 will approach switch lever 72 from the opposite direction. The operation of second trigger mechanism 76, upon movement in the opposite direction is identical and will, therefore, not be further described.
Referring to FIG. 2, when switch lever 72 is switched to the second mode, first member 68 of switch 52 is positioned between second radial port 60 and third radial port 62 2 0 and second member 70 is positioned between fourth radial port 64 and fifth radial port 66.
Gas continues to be supplied through gas inlet 48 flowing into barrel, however now as it encounters first member 68 it concurrently passes out first radial port 59 and second radial port 60. Gas flowing out of first radial port 59 re-enters barrel 54 through fifth radial port 66, where it encounters a dead end in barrel 54 created by the positioning of second member 70.
2 5 Gas flowing out of second radial port 60 passes through second side fluid communication port 34 into piston chamber 30 on second side 28 of piston 24. The pressure exerted by the in flowing gas causes piston 24 to move in the second direction, as indicated by arrow 18. The movement of piston 30 in the second direction, forces exhaust gas out of piston chamber 30 through first side fluid communication port 32 and into barrel 54 through fourth radial port 3 0 64. Exhaust gas in barrel 54 is confined between first member 68 and second member 70.
The exhaust gas then exits out of third radial port 62 to gas exhaust 50.
Referring to FIG. 1 and FIG. 2, when drive 10 is operated with control system 12, considerably less gas is used. The reason for this is that all of the gas supplied is used to power piston 24, as opposed to other systems in which gas at higher pressures was required to overcome the biasing force of a return spring for the reciprocating shaft.
There are some 5 systems which operate by having a constant bleed of gas through poppet valves. Control system has a much lower gas consumption than such systems and is, therefore, a more environmentally responsible system. Referring to FIG. 4a through 4g, the use of trigger mechanisms 74 and 76, help further facilitated slow, low pressure operation.
What is meant by slow is speeds as low as one stroke every three minutes. What is meant by low pressure is 10 pressure in a range of 7 to 10 psi. Referring to FIG. 5, the use of seal carrier 104 in place of chevron packing, assists further in reaching this objective of slow, low pressure operation, by reducing overall friction and resistance considerably. It also serves a secondary function of maintaining displacement rod 23 centred in housing 98. It is preferred that grease be packed into central bore 110 between interior seal rings 118 at the time of insertion of displacement rod 23. This gives annular seal 44 a self lubrication quality and further reduces friction as the grease will move between interior seal rings 118, during reciprocating movement. Referring to FIG.1 and FIG. 2, it will be understood that the speed of the unit is ultimately determined by gas control valve 49 position upstream of gas inlet 48. The stroke of reciprocating shaft 14 is set by the positioning of first trigger mechanism 74 and second trigger mechanism 76.
In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the 2 5 possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as 3 0 hereinafter defined in the Claims.
Claims (8)
1. An apparatus, comprising in combination:
a drive having a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction, the reciprocating shaft having a first end and a second end;
a piston mounted at the first end of the shaft, the piston having a first side and a second side;
a fluid retaining piston chamber housing the piston, the piston chamber having at least one first side fluid communication port on the first side of the piston and at least one second side fluid communication port on the second side of the piston;
the second end of the shaft serving an intended function as it reciprocates;
a control system, comprising:
a gas manifold having:
a gas inlet adapted for connection to a gas source supplying gas to the gas manifold;
a gas exhaust adapted to exhaust gas from the gas manifold;
means for configuring the gas manifold in a first mode, with the gas inlet connected to the at least one first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction and the at least one second side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction;
means for configuring the gas manifold in a second mode, with the gas inlet connected to the at least one second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction and the at least one first side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction; and means for switching between the first mode and the second mode, such that the shaft of the drive is reciprocated solely by gas pressure.
a drive having a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction, the reciprocating shaft having a first end and a second end;
a piston mounted at the first end of the shaft, the piston having a first side and a second side;
a fluid retaining piston chamber housing the piston, the piston chamber having at least one first side fluid communication port on the first side of the piston and at least one second side fluid communication port on the second side of the piston;
the second end of the shaft serving an intended function as it reciprocates;
a control system, comprising:
a gas manifold having:
a gas inlet adapted for connection to a gas source supplying gas to the gas manifold;
a gas exhaust adapted to exhaust gas from the gas manifold;
means for configuring the gas manifold in a first mode, with the gas inlet connected to the at least one first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction and the at least one second side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction;
means for configuring the gas manifold in a second mode, with the gas inlet connected to the at least one second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction and the at least one first side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction; and means for switching between the first mode and the second mode, such that the shaft of the drive is reciprocated solely by gas pressure.
2. The apparatus as defined in Claim 1, wherein there is only one first side fluid communication port and only one second side fluid communication port.
3. The apparatus as defined in Claim 2, wherein:
the gas manifold consists of a barrel having a first end and a second end, the gas inlet being positioned at the first end, and a first radial port, a second radial port, a third radial port, a fourth radial port, and a fifth radial port being sequentially spaced from the first end to the second end the second radial port being connected to the second side fluid communication port, the third radial port being connected to the gas exhaust, the fourth radial port being connected to the first side fluid communication port, the first radial port being connected to the fifth radial port;
the means of switching between the first mode and the second mode is a switch having a first member and a second member that move axially in the barrel;
in the first mode the first member of the switch is positioned between the first radial port and the second radial port and the second member of the switch is positioned between the third radial port and the fourth radial port, such that gas supplied through the gas inlet flows into the barrel, encounters the first member and passes out the first radial port, re-enters the barrel at the fifth radial port, encounters the second member and then passes out the fourth radial port through the first side fluid communication port into the piston chamber on the first side of the piston causing the piston to move in the first direction, the movement of the piston in the first direction forcing gas out of the piston chamber through the second side fluid communication port and through the second radial port into the barrel, is confined in the barrel between the first member and the second member and passes out third radial port to the gas exhaust;
in the second mode the first member of the switch is positioned between the second radial port and the third radial port and the second member of the switch is positioned between the fourth radial port and the fifth radial port, such that gas supplied through the gas inlet flows into the barrel encounters the first member and concurrently passes out the first radial port and the second radial port, gas flowing out of the first radial port re-enters the barrel at the fifth radial port where it encounters a dead end in the barrel created by the second member, gas flowing out of the second radial port passes through the second side fluid communication port into the piston chamber on the second side of the piston causing the piston to move in the second direction, the movement of the piston in the second direction forcing gas out of the piston chamber through the first side fluid communication port and through the fourth radial port into the barrel, whereby gas confined in the barrel between the first member and the second member can only exit out the third radial port to the gas exhaust.
the gas manifold consists of a barrel having a first end and a second end, the gas inlet being positioned at the first end, and a first radial port, a second radial port, a third radial port, a fourth radial port, and a fifth radial port being sequentially spaced from the first end to the second end the second radial port being connected to the second side fluid communication port, the third radial port being connected to the gas exhaust, the fourth radial port being connected to the first side fluid communication port, the first radial port being connected to the fifth radial port;
the means of switching between the first mode and the second mode is a switch having a first member and a second member that move axially in the barrel;
in the first mode the first member of the switch is positioned between the first radial port and the second radial port and the second member of the switch is positioned between the third radial port and the fourth radial port, such that gas supplied through the gas inlet flows into the barrel, encounters the first member and passes out the first radial port, re-enters the barrel at the fifth radial port, encounters the second member and then passes out the fourth radial port through the first side fluid communication port into the piston chamber on the first side of the piston causing the piston to move in the first direction, the movement of the piston in the first direction forcing gas out of the piston chamber through the second side fluid communication port and through the second radial port into the barrel, is confined in the barrel between the first member and the second member and passes out third radial port to the gas exhaust;
in the second mode the first member of the switch is positioned between the second radial port and the third radial port and the second member of the switch is positioned between the fourth radial port and the fifth radial port, such that gas supplied through the gas inlet flows into the barrel encounters the first member and concurrently passes out the first radial port and the second radial port, gas flowing out of the first radial port re-enters the barrel at the fifth radial port where it encounters a dead end in the barrel created by the second member, gas flowing out of the second radial port passes through the second side fluid communication port into the piston chamber on the second side of the piston causing the piston to move in the second direction, the movement of the piston in the second direction forcing gas out of the piston chamber through the first side fluid communication port and through the fourth radial port into the barrel, whereby gas confined in the barrel between the first member and the second member can only exit out the third radial port to the gas exhaust.
4. The apparatus as defined in Claim 1, wherein the means for switching between the first mode and the second mode is a snap acting switch having a switch lever that is activated when the reciprocating shaft moves in the first direction by a first trigger mechanism carried by the reciprocating shaft and is activated when the reciprocating shaft moves in the second direction by a second trigger mechanism carried by the reciprocating shaft.
5. The apparatus as defined in Claim 2, wherein each of the first trigger mechanism and the second trigger mechanism are comprised of:
a spring coiled around the reciprocating shaft, the spring having a fixed end and a free end;
a stop engaging the fixed end of the spring and adapted to prevent axial movement of the spring along the reciprocating shaft; and a trigger member biased by the free end of the spring.
a spring coiled around the reciprocating shaft, the spring having a fixed end and a free end;
a stop engaging the fixed end of the spring and adapted to prevent axial movement of the spring along the reciprocating shaft; and a trigger member biased by the free end of the spring.
6. The apparatus as defined in Claim 5, wherein the trigger member is an annular plate having a central aperture through which the reciprocating shaft extends, a second stop being positioned adjacent to the trigger member opposed to the spring, the second stop being adapted to limit axial movement of the trigger member along the reciprocating shaft.
7. An apparatus, comprising in combination:
a pump having a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction, the reciprocating shaft having a first end and a second end;
a piston mounted at the first end of the shaft, the piston having a first side and a second side;
a fluid retaining piston chamber housing the piston, the piston chamber having at least one first side fluid communication port on the first side of the piston and at least one second side fluid communication port on the second side of the piston;
the second end of the shaft being coupled to a displacement rod which is adapted to control flow from a chemical source, such that when the shaft and displacement rod move reciprocally in the second direction a flow of chemical is released and when the shaft and displacement rod move in the first direction, the flow of chemical is blocked;
and an annular seal positioned around the displacement rod to prevent the incursion of chemicals the chemical source;
a control system, comprising:
a gas manifold having:
a gas inlet adapted for connection to a gas source supplying gas to the gas manifold;
a gas exhaust adapted to exhaust gas from the gas manifold;
means for configuring the gas manifold in a first mode, with the gas inlet connected to the at least one first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction and the at least one second side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction;
means for configuring the gas manifold in a second mode, with the gas inlet connected to the at least one second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction and the at least one first side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction; and means for switching between the first mode and the second mode, such that the shaft of the pump is reciprocated solely by gas pressure.
a pump having a reciprocating shaft which reciprocally moves in a first direction and a second direction opposed to the first direction, the reciprocating shaft having a first end and a second end;
a piston mounted at the first end of the shaft, the piston having a first side and a second side;
a fluid retaining piston chamber housing the piston, the piston chamber having at least one first side fluid communication port on the first side of the piston and at least one second side fluid communication port on the second side of the piston;
the second end of the shaft being coupled to a displacement rod which is adapted to control flow from a chemical source, such that when the shaft and displacement rod move reciprocally in the second direction a flow of chemical is released and when the shaft and displacement rod move in the first direction, the flow of chemical is blocked;
and an annular seal positioned around the displacement rod to prevent the incursion of chemicals the chemical source;
a control system, comprising:
a gas manifold having:
a gas inlet adapted for connection to a gas source supplying gas to the gas manifold;
a gas exhaust adapted to exhaust gas from the gas manifold;
means for configuring the gas manifold in a first mode, with the gas inlet connected to the at least one first side fluid communication port to supply gas to the piston chamber on the first side of the piston to cause the piston to move in a first direction and the at least one second side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the second side of the piston as the piston moves in the first direction;
means for configuring the gas manifold in a second mode, with the gas inlet connected to the at least one second side fluid communication port to supply gas to the piston chamber on the second side of the piston to cause the piston to move in a second direction and the at least one first side fluid communication port concurrently being connected to the gas exhaust to exhaust gas from the piston chamber on the first side of the piston as the piston moves in the second direction; and means for switching between the first mode and the second mode, such that the shaft of the pump is reciprocated solely by gas pressure.
8. The apparatus as defined in Claim 7, wherein the annular seal comprises:
a housing having an interior sidewall defining a cylindrical seal chamber;
a cylindrical seal carrier adapted to fit within the cylindrical seal chamber, the seal carrier having an exterior surface and an interior surface defining a central bore adapted to receive the displacement rod, at least one exterior circumferential seal groove on the exterior surface of the seal carrier and at least one interior circumferential seal groove on the interior surface of the seal carrier;
an exterior seal ring positioned in the at least one exterior circumferential seal groove and adapted to from a seal between the exterior surface of the seal carrier and the interior surface of the housing;
an interior seal ring positioned in the at least one interior circumferential seal groove and adapted to from a seal between the interior surface of the seal carrier and the displacement rod; and an end cap closing the seal chamber and providing access to permit the insertion and removal of the seal carrier.
a housing having an interior sidewall defining a cylindrical seal chamber;
a cylindrical seal carrier adapted to fit within the cylindrical seal chamber, the seal carrier having an exterior surface and an interior surface defining a central bore adapted to receive the displacement rod, at least one exterior circumferential seal groove on the exterior surface of the seal carrier and at least one interior circumferential seal groove on the interior surface of the seal carrier;
an exterior seal ring positioned in the at least one exterior circumferential seal groove and adapted to from a seal between the exterior surface of the seal carrier and the interior surface of the housing;
an interior seal ring positioned in the at least one interior circumferential seal groove and adapted to from a seal between the interior surface of the seal carrier and the displacement rod; and an end cap closing the seal chamber and providing access to permit the insertion and removal of the seal carrier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2493340 CA2493340A1 (en) | 2005-02-01 | 2005-02-01 | Control system for reciprocating drive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2493340 CA2493340A1 (en) | 2005-02-01 | 2005-02-01 | Control system for reciprocating drive |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2493340A1 true CA2493340A1 (en) | 2006-08-01 |
Family
ID=36764071
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2493340 Abandoned CA2493340A1 (en) | 2005-02-01 | 2005-02-01 | Control system for reciprocating drive |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2493340A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011053424A1 (en) * | 2009-10-29 | 2011-05-05 | Bj Services Company Llc | Fluidic impulse generator |
| US8082837B2 (en) | 2007-09-17 | 2011-12-27 | Plainsman Mfg. Inc. | Control system for reciprocating device |
| US8092191B2 (en) | 2007-10-15 | 2012-01-10 | Plainsman Mfg. Inc. | Control system for reciprocating device |
-
2005
- 2005-02-01 CA CA 2493340 patent/CA2493340A1/en not_active Abandoned
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8082837B2 (en) | 2007-09-17 | 2011-12-27 | Plainsman Mfg. Inc. | Control system for reciprocating device |
| US8092191B2 (en) | 2007-10-15 | 2012-01-10 | Plainsman Mfg. Inc. | Control system for reciprocating device |
| WO2011053424A1 (en) * | 2009-10-29 | 2011-05-05 | Bj Services Company Llc | Fluidic impulse generator |
| US8272404B2 (en) | 2009-10-29 | 2012-09-25 | Baker Hughes Incorporated | Fluidic impulse generator |
| US9033003B2 (en) | 2009-10-29 | 2015-05-19 | Baker Hughes Incorporated | Fluidic impulse generator |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Dead |
Effective date: 20130719 |