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A fluid-driven reciprocating pump comprises a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber, a mechanical connection coupling the two displaceable members for reciprocation together, and means for connecting the driving chamber of one pu

A fluid-driven reciprocating pump comprises a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber, a mechanical connection coupling the two displaceable members for reciprocation together, and means for connecting the driving chamber of one pumping head to a source of pressurized fluid and the pumping chamber of that pumping head to a source of material to be pumped. The pump further includes means for connecting the driving chamber of the other pumping head to a source of pressurized fluid and for selectively connecting the pumping chamber of the other pumping head either to a source of material to be pumped to produce a double-action pumping operation wherein the material is pumped during both reciprocations of the displaceable members, or to the source of pressurized fluid to produce a single-action pumping operation wherein the material is pumped during only one of the two reciprocations of the displaceable members.

대표청구항 ▼

1. A fluid-driven reciprocating pump comprising: a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber on opposite sides thereof; a mechanical connection coupling the two displaceable members for reciprocating together; means including a

1. A fluid-driven reciprocating pump comprising: a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber on opposite sides thereof; a mechanical connection coupling the two displaceable members for reciprocating together; means including a main valve and a pilot valve for connecting the driving chamber of at least one of said pumping heads to a source of pressurized fluid and the pumping chamber of said one pumping head to a source of material to be pumped; and means including said main valve and said pilot valve for connecting the driving chamber of the other pumping head to a source of pressurized fluid; said main valve including a cylinder, a stem movable in said cylinder, a pair of pistons fixed to said movable stem, a plurality of ports controlled by said pistons, and a diaphragm connected to one end of said stem and closing one end of said cylinder to define a fluid control chamber therein; said pilot valve including a stem reciprocable by said mechanical connection such that in one position of said two displaceable members the pilot valve applies the source of pressurized fluid to said control chamber of the main valve to move said main valve stem in the direction to connect the driving chamber of one pumping head to the source of pressurized fluid, whereas in the opposite position of said two displaceable members the pilot valve interrupts the application of the source of pressurized fluid to said control chamber of the main valve; one of said pistons of the main valve having a larger cross-sectional area exposed to the source of pressurized fluid than the other piston of said main valve, such as to move said main valve stem in the opposite direction, to connect the driving chamber of the other pumping head to the source of pressurized fluid, when the pilot valve interrupts the application of the pressurized fluid to said control chamber of the main valve. 2. The pump according to claim 1, wherein the driving chamber of said other pumping head is connected to the source of pressurized fluid, and the pumping chamber of said other pumping head is connected to another source of material to be pumped, thereby providing a double-action pumping operation capable of pumping the same or different materials from two different sources. 3. The pump according to claim 1, wherein each of said displaceable members is a diaphragm and are coupled for reciprocation together by a connecting rod. 4. The pump according to claim 1, wherein the source of pressurized fluid is a liquid supply line, and the outlets of the pumping chambers of the two pumping heads are connected to said liquid supply line downstream of the reciprocating pump for injecting said material into the supply line. 5. The pump according to claim 4, wherein said liquid supply line includes a reducing valve between the inlet to the reciprocating pump, and the outlet thereof to the supply line. 6. The pump according to claim 4, further including an externally-powered booster pump for boosting the pressure of the liquid from the supply line before applied to the driving chambers of the two pumping heads. 7. The pump according to claim 4, further including a presettable regulating valve between the supply line and the driving chamber of the two pumping heads for presetting the period of each reciprocating stroke. 8. The pump according to claim 4, further including presettable members on said connecting rod between the two diaphragms for presetting the magnitude of each reciprocation stroke. 9. The pump according to claim 8, wherein said presettable members are actuator elements carried by said connecting rod and presettable at predetermined distances away from a pilot valve therebetween, which actuator elements actuate the pilot valve to terminate the respective reciprocation stroke and to start the next stroke. 10. The pump according to claim 9, wherein said pair of actuator elements are movable together by a threaded pin attached to said connecting rod towards or away from the pilot valve therebetween. 11. A reciprocating pump for injecting a fertilizer into the water of a pressurized water supply line, comprising: a pair of pumping heads each containing a displaceable member defining a driving chamber and a pumping chamber on opposite sides thereof; a mechanical connection coupling the two displaceable members for reciprocation together; means including a main valve and a pilot valve for connecting the driving chamber of at least one of said pumping heads to the pressurized water supply line and the pumping chamber of said one pumping head to a first source of fertilizer to be pumped; and means including said main valve and said pilot valve for connecting the driving chamber of the other pumping head to the pressurized water supply line; said main valve including a cylinder, a stem movable in said cylinder, a pair of pistons fixed to said movable stem, a plurality of ports controlled by said pistons, and a diaphragm connected to one end of said stem and closing one end of said cylinder to define a fluid control chamber therein; said pilot valve including a stem reciprocable by said mechanical connection such that in one position of said two displaceable members the pilot valve applies the source of pressurized fluid to said control chamber of the main valve to move said main valve stem in the direction to connect the driving chamber of one pumping head to the source of pressurized fluid, whereas in the opposite position of said two displaceable members the pilot valve interrupts the application of the source of pressurized fluid to said control chamber of the main valve; one of said pistons of the main valve having a larger cross-sectional area exposed to the source of pressurized fluid than the other piston of said main valve, such as to move said main valve stem in the opposite direction, to connect the driving chamber of the other pumping head to the source of pressurized fluid, when the pilot valve interrupts the application of the pressurized fluid to said control chamber of the main valve. 12. The pump according to claim 11, wherein said pressurized water supply line includes a reducing valve between the inlet to the reciprocating pump, and its outlet to the supply line. 13. The pump according to claim 11, further including an externally-powered booster pump for boosting the pressure of the liquid from the water supply line before applied to the driving chambers of the two pumping heads. 14. The pump according to claim 11, further including a presettable regulating valve between the water supply line and the driving chamber of the two pumping heads for presetting the period of each reciprocating stroke. 15. The pump according to claim 11, wherein said displaceable members are diaphragms and are coupled for reciprocation together by a connecting rod. 16. The pump according to claim 15, further including presettable members on said connecting rod between the two diaphragms for presetting the magnitude of each reciprocation stroke. 17. The pump according to claim 16, wherein said presettable members are actuator elements carried by said connecting rod and presettable at predetermined distances away from a pilot valve therebetween, which actuator elements actuate the pilot valve to terminate the respective reciprocation stroke and to start the next stroke.