Fuel pump

Claim 2

A fuel pump for supplying fuel from a fuel source to the carburetor of a two-cycle internal-combustion engine having a plurality of cylinders, comprising first and second and third chambers, pressure-responsive diaphragm means extending across each of said chambers, a fuel-supply chamber having a fuel-source connection and having overlapping connection with said first and second chambers, an inlet check valve at the connection between said fuel-supply chamber and said second chamber, means including an outlet check valve connecting said second and third chambers, said third chamber including a fuel-output connection, first crankcase-connection means on the opposite side of the diaphragm at said first chamber for a first phase of pulsed operation thereof in accordance with a first-phase, second crankcaseconnection means on the opposite side of the diaphragm at said second chamber for pulsed operation thereof in accordance with a second phase in phase-displaced relation to said first phase, and third crankcase-connection means on the opposite side of the diaphragm at said third chamber for pulsed operation thereof in phase-displaced relation with said second phase.

Claim 3

The pump of claim 1, in which said first and third crankcase-connection means are connected to each other.

Claim 4

The pump of claim 1, in which the effective diaphragm area of said first chamber is less than that of said second chamber.

Claim 5

The pump of claim 3, in which the first-chamber diaphragm area is in the order of one half the second-chamber diaphragm area.

Claim 6

A fuel pump for supplying fuel from a fuel source to the fuel inlet of an internal-combustion engine having an output shaft and shaft-connected means for generating in separate outlets first and second fluid-pressure pulse trains in phase-displaced relation and synchronous with shaft rotation, said pump comprising first and second chambers with pressure-responsive diaphragm means extending across each of said chambers, means including a fuel-supply chamber interconnecting said first and second chambers, an inlet check valve at the connection between said fuel-supply chamber and said secOnd chamber, means including an outlet check valve connected to said second chamber and having means for supplying the output of said outlet check valve to the fuel inlet of the engine, first connection means on the opposite side of the diaphragm at said first chamber for connection to the first pulsed fluid-pressure outlet of such an associated internal-combustion engine, and second connection means on the opposite side of the diaphragm at said second chamber for connection to the second pulsed fluid-pressure outlet of the engine, whereby said inlet check valve is subjected to the push-pull differential-pressure fluctuation generated by phase-displaced excitation of the respective diaphragms at said first and second chambers.

Claim 7

A fuel pump for supplying fuel from a fuel source to the fuel inlet of an internal-combustion engine having an output shaft and shaft-connected means for generating in separate outlets first and second fluid-pressure pulse trains in phase-displaced relation and synchronous with shaft rotation, said pump comprising first and second chambers with pressure-responsive diaphragm means extending across each of said chambers, means including a fuel-supply chamber interconnecting said first and second chambers, an inlet check valve at the connection between said fuel-supply chamber and said secOnd chamber, means including an outlet check valve connected to said second chamber and having means for supplying the output of said outlet check valve to the fuel inlet of the engine, first connection means on the opposite side of the diaphragm at said first chamber for connection to the first pulsed fluid-pressure outlet of such an associated internal-combustion engine, and second connection means on the opposite side of the diaphragm at said second chamber for connection to the second pulsed fluid-pressure outlet of the engine, whereby said inlet check valve is subjected to the push-pull differential-pressure fluctuation generated by phase-displaced excitation of the respective diaphragms at said first and second chambers.

Claim 8

The pump of claim 5, in which said fuel-supply chamber includes strainer means separating the space within said chamber into an unstrained-fuel inlet volume and a strained-fuel outlet volume, said strained-fuel outlet volume communicating directly with both said inlet check valve and said first-mentioned chamber, whereby both said first and second diaphragm-operated chambers operate only upon fuel which has passed said strainer means.

Claim 9

A pump for supplying fluid from a fluid source to a fluid-delivery outlet, cyclically operative means for developing separate pulsed-cycle outputs in constant phase-displaced relation, said pump comprising first and second chambers with flexible diaphragm means extending across each of said chambers, means including a fluidsupply chamber interconnecting said first and second chambers, an inlet check valve at the connection between said fluid-supply chamber and said second chamber, means including an outlet check valve connected to said second chamber and having means for supplying the output of said outlet check valve to said fluid-delivery outlet, first connection means on the opposite side of the diaphragm at said first chamber for operative connection to one of said pulsed-cycle outputs of said cyclically operative means, and second connection means on the opposite side of the diaphragm at said second chamber for operative connection to the other of said pulsed-cycle outputs of said cyclically operative means, whereby said inlet check valve is subjected to the push-pull differential-pressure fluctuation generated by phase-displaced excitation of the respective diaphragms at said first and second chambers.

Claim 10

A pump for supplying fluid from a fluid source to a fluid-delivery outlet, cyclically operative means for developing separate pulsed-cycle outputs in constant phase-displaced relation, said pump comprising first and second chambers with flexible diaphragm means extending across each of said chambers, means including a fluidsupply chamber interconnecting said first and second chambers, an inlet check valve at the connection between said fluid-supply chamber and said second chamber, means including an outlet check valve connected to said second chamber and having means for supplying the output of said outlet check valve to said fluid-delivery outlet, first connection means on the opposite side of the diaphragm at said first chamber for operative connection to one of said pulsed-cycle outputs of said cyclically operative means, and second connection means on the opposite side of the diaphragm at said second chamber for operative connection to the other of said pulsed-cycle outputs of said cyclically operative means, whereby said inlet check valve is subjected to the push-pull differential-pressure fluctuation generated by phase-displaced excitation of the respective diaphragms at said first and second chambers.