Dual-element centrifugal pump pressure responsive flow regulator means

Claim 2

A pump comprising in combination fluid intake means including at least one inlet conduit; first impeller means which operates over the entire output range; second impeller means which operates during high output periods; shaft means for connecting said impeller means to a source of rotary power; flow regulator means for intercommunicating said first and second impeller means so that said impeller means pump is series during high output periods; means for (acontrolling the admission of fluid to said second impeller means, said control means being in communication with said flow regulator means such that said control means activates said flow regulator means; and means for receiving the discharged fluid from either of the impeller means.

Claim 3

A pump comprising in combination an inlet conduit; first impeller means which operates over the entire output range; second impeller means which operates during high output periods; shaft means for connecting said impeller means to a source of rotary power; venting means for communicating said second impeller means to atmosphere during dry operation; valving means for controlling the admission of fluid to said second impeller means; said valving means also controlling the venting means for said second impeller means; flow regulator means for intercommunicating said first and second impeller means, said flow regulator means including a plurality of passages interconnecting said first and second impellers means and a biased-closed regulator valve interposed within said passages and in communication with said valving means, so that when a higher flow output is required, said regulator valve opens thus permitting said first impeller means to deliver its output to said second impeller means through said interconnecting passages; and fluid receiving means for communicating the discharged fluid from either of the impellers to a common discharge conduit.

Claim 4

A pump comprising in combination an inlet conduit; first impeller means which operates over the entire output range; second impeller means which operates during high output periods; shaft means for connecting said impeller means to a source of rotary power; venting means for communicating said second impeller means to atmosphere during dry operation; valving means for controlling the admission of fluid to said second impeller means; said valving means also controlling the venting means for said second impeller means; flow regulator means for intercommunicating said first and second impeller means, said flow regulator means including a plurality of passages interconnecting said first and second impellers means and a biased-closed regulator valve interposed within said passages and in communication with said valving means, so that when a higher flow output is required, said regulator valve opens thus permitting said first impeller means to deliver its output to said second impeller means through said interconnecting passages; and fluid receiving means for communicating the discharged fluid from either of the impellers to a common discharge conduit.

Claim 5

A pump as recited in claim 2 in which the regulator valve is biased closed under the influence of a piston rod, said piston rod being part of an adjacent but separate piston-cylinder assembly.

Claim 6

A pump as recited in claim 3 in which the regulator valve encases a compression spring, said spring being of a predetermined strength so that said regulator valve will open when not under the influence of said piston-cylinder assembly and so that said regulator valve will close independently of said piston assembly should the first impeller means stop pumping while the second impeller means remains in operation.

Claim 7

A pump as recited in claim 2 in which the regulator valve is biased closed by a compression spring positioned within said plurality of passages on the upstream side of said regulator valve.

Claim 8

A pump as recited in claim 2 including the following additional elements: means for controlling the rate of fluid through said intereconnecting passages, said means comprising in combination a housing encasing said second impeller meanS, said housing containing an annulus therein, said annulus being located in said housing in an area where the pressure is less than the pressure at said first impeller means periphery when both first and second impeller means are in pumping operation, so that this pressure differential determines the rate of flow of fluid passing through said passages connecting said first impeller means to said second impeller means.

Claim 9

A pump as recited in claim 2 including the following additional elements: means for controlling the rate of flow of fluid through said interconnecting passages, said means comprising in combination a housing encasing said second impeller means, said housing containing an orifice therein, said orifice being located at a point in said housing where the pressure is less than the pressure at said first impeller means periphery when said first and second impeller means are in pumping operation, so that this pressure differential between said orifice and said first impeller means periphery determines the rate of flow of fluid passing through the passageways connecting the first impeller means to the second impeller means.

Claim 10

A pump comprising in combination an inlet conduit; a first impeller which operates over the entire output range; a second impeller which operates during high output periods; shaft means for connecting said impellers to a source of rotary power; venting means for communicating said second impeller to atmosphere during dry operation; flow regulator means for intercommunicating said first and second impellers so that said impellers pump in series during high output periods, said regulator means comprising a plurality of passages interconnecting said first and second impellers and a biased-closed regulator valve interposed within said passages; means for controlling the rate of flow of fluid through said interconnecting passages, said means including housing means encasing said second impeller, said housing means containing an annulus therein, said annulus being located in said second impeller''s housing at an area where the pressure is less than the pressure at said first impeller''s periphery when both first and second impellers are in pumping operation, so that this pressure differential determines the rate of flow of fluid passing through said passages connecting said first impeller to said second impeller; valving means for controlling the admission of fluid to said second impeller, said flow regulator means, and said venting means for said second impeller said valving means being actuated by a hydraulic signal from an external fluid control unit; and fluid receiving means for communicating the discharged fluid from either of the impellers to a common discharge conduit; said discharge conduit having a first and second check valve interposed therein, said first valve being associated with said first impeller, said second valve associated with said second impeller so that said first valve opens during low output periods, and said first valve closes and said second valve opens during high output periods.

Claim 11

A pump comprising in combination an inlet conduit; a first impeller which operates over the entire output range; a second impeller which operates during high output periods; shaft means for connecting said impellers to a source of rotary power; venting means for communicating said second impeller to atmosphere during dry operation; flow regulator means for intercommunicating said first and second impellers so that said impellers pump in series during high output periods, said regulator means comprising a plurality of passages interconnecting said first and second impellers and a biased-closed regulator valve interposed within said passages; means for controlling the rate of flow of fluid through said interconnecting passages, said means including housing means encasing said second impeller, said housing means containing an annulus therein, said annulus being located in said second impeller''s housing at an area where the pressure is less than the pressure at said first impeller''s periphery when both first and second impellers are in pumping operation, so that this pressure differential determines the rate of flow of fluid passing through said passages connecting said first impeller to said second impeller; valving means for controlling the admission of fluid to said second impeller, said flow regulator means, and said venting means for said second impeller said valving means being actuated by a hydraulic signal from an external fluid control unit; and fluid receiving means for communicating the discharged fluid from either of the impellers to a common discharge conduit; said discharge conduit having a first and second check valve interposed therein, said first valve being associated with said first impeller, said second valve associated with said second impeller so that said first valve opens during low output periods, and said first valve closes and said second valve opens during high output periods.

Claim 12

A pump comprising in combination an inlet conduit; a first impeller which operates over the entire output range; a second impeller which operates during high output periods; shaft means for connecting said impeller to a source of rotary power; venting means for communicating said second impeller to atmosphere during dry operation; flow regulator means for intercommunicating said first and second impellers so that said impellers pump in series during high output periods, said regulator means comprising a plurality of passages interconnecting said first and second impellers and a biased-closed regulator valve interposed within said passages; and means for controlling the rate of flow of fluid through said interconnecting passages, said means including housing means encasing said second impeller, said second impeller housing means containing an orifice therein, said Orifice being located at a point in said second impeller''s housing where the pressure is less than the pressure at said first impeller''s periphery when both first and second impellers are in pumping operation, so that this pressure differential between said orifice and said first impeller''s periphery determine the rate of flow of fluid passing through the passageways connecting the first impeller to the second impeller.

Claim 13

A pump comprising in combination an inlet conduit; a first impeller which operates over the entire output range; a second impeller which operates during high output periods; shaft means for connecting said impeller to a source of rotary power; venting means for communicating said second impeller to atmosphere during dry operation; flow regulator means for intercommunicating said first and second impellers so that said impellers pump in series during high output periods, said regulator means comprising a plurality of passages interconnecting said first and second impellers and a biased-closed regulator valve interposed within said passages; and means for controlling the rate of flow of fluid through said interconnecting passages, said means including housing means encasing said second impeller, said second impeller housing means containing an orifice therein, said Orifice being located at a point in said second impeller''s housing where the pressure is less than the pressure at said first impeller''s periphery when both first and second impellers are in pumping operation, so that this pressure differential between said orifice and said first impeller''s periphery determine the rate of flow of fluid passing through the passageways connecting the first impeller to the second impeller.