Patent ID: 11873802
Assignee: GRACO MINNESOTA INC.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A pump configured to serially compress a gas, the pump comprising:
a housing;
a first compression stage having a first diaphragm, a first stage inlet, and a first stage outlet, the first diaphragm configured to reciprocate on a pump axis to alter a volume of a first compression chamber of the first compression stage;
a second compression stage having a second diaphragm a second stage inlet and a second stage outlet, the second diaphragm configured to reciprocate on the pump axis to alter a volume of a second compression chamber of the second compression stage;
a first cover at least partially defining the first compression chamber and mounted to a first end of the housing, wherein the first cover comprises:
a first inner plate mounted to the housing; and
a first outer plate mounted to the first inner plate such that the first inner plate is disposed between the first outer plate and the first diaphragm;
wherein first stage inlet is formed through the first inner plate and the first outer plate, and wherein the first stage outlet is formed through the first inner plate and the first outer plate;

a second cover at least partially defining the second compression chamber and mounted to a second end of the housing, wherein the second cover comprises:
a second inner plate mounted to the housing; and
a second outer plate mounted to the second inner plate such that the second inner plate is disposed between the second outer plate and the second diaphragm;
wherein second stage inlet is formed through the second inner plate and the second outer plate, and wherein the second stage outlet is formed through the second inner plate and the second outer plate;

a first check valve configured to allow flow into the first compression chamber and prevent retrograde flow out of the first compression chamber;
a second check valve captured between the first inner plate and the first outer plate, the second check valve configured to allow flow out of the first compression chamber and prevent retrograde flow into the first compression chamber, wherein the second check valve is configured to open based on a pressure within the first compression chamber reaching a first pressure threshold;
a third check valve captured between the second inner plate and the second outer plate, the third check valve configured to allow flow out of the second compression chamber and prevent retrograde flow into the second compression chamber, wherein the third check valve is configured to open based on a pressure in the second compression chamber exceeding a crack pressure greater than the first pressure threshold such that the crack pressure is configured to be built in the second compression chamber over a plurality of pumping cycles of the first diaphragm;
a first inlet fitting mounted to the first outer plate and fluidly connected to the first stage inlet;
a first outlet fitting mounted to the first outer plate and fluidly connected to the first stage outlet;
a second inlet fitting mounted to the second outer plate and fluidly connected to the second stage inlet;
a second outlet fitting mounted to the second outer plate and fluidly connected to the second stage outlet; and
a drive disposed at least partially between the first diaphragm and the second diaphragm, the drive operably connected to the first diaphragm and the second diaphragm to displace the first diaphragm through a first suction stroke and to displace the second diaphragm through a second suction stroke; and
wherein the first compression stage is fluidly connected to the second compression stage such that gas compressed in the first compression chamber in the first compression stage is routed to the second compression chamber.