Electric motor-driven, double-acting pump having pressure-responsive actuation

Claim 2

In a liquid pumping system for an airless spray gun wherein liquid is to be supplied to the gun under substantially uniform pressure in the range of up to 3000 pounds per square inch and the gun is intermittently turned off and on thereby tending to cause fluctuations in the liquid pressure at the gun, a pump and operating mechanism therefor comprising, in combination, a double-acting positive displacement pump having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of said pump cylinder having a cylinder therein aligned with said pump cylinder, a crosshead reciprocably and guidably mounted in said crosshead cylinder and connected to the upper end of said piston rod, and a connecting rod pivotally connected at its lower end to said crosshead; a high speed electric motor having a drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft and including an electric clutch; said gear train having an output shaft including an eccentric pivotally connected to the upper end of said connecting rod for positively interconnecting said motor and said piston for reciprocating said piston in said cylinder; said crosshead isolating said pump and said piston and piston rod from the gyratory movement of said eccentric and said connecting rod; an outlet manifold having an inlet connected to said pump outlet and an outlet, an adjustable pressure responsive switch on said manifold responsive to the pressure of the liquid flowing through said manifold, an electric circuit connected to said clutch including said switch and responsive thereto to cause said pump to start and stop operating as a function of pressure, said switch being operative to activate and deactivate said clutch for causing said pump to stop operating when the liquid pressure exceeds a preselected pressure and for causing said pump to start operating when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond

Claim 3

In a liquid pumping system for plural component airless spray gun means wherein at least two liquids are to be supplied to the gun means under substantially uniform pressures in the range of up to 3000 pounds per square inch and the gun means is intermittently turned off and on thereby tending to cause fluctuations in the liquid pressures at the gun, a pump and operating mechanism therefor comprising, in combination, a pair of double-acting positive displacement pumps each having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of each of said pump cylinders having a cylinder therein aligned with the respective pump cylinder, a crosshead reciprocably and guidably mounted in each said crosshead cylinder and connected to the upper end of the respective piston rod, a connecting rod pivotally connected at its lower end to each of said crossheads; a high-speed electric motor having a drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft and including an electric clutch; said gear train having a pair of output shafts each including an eccentric pivotally connected to the upper end of a respective one of said connecting rods for positively interconnecting said motor and said pistons for reciprocating said pistons in said cylinders; said crossheads isolating said pumps and said pistons and piston rods from the gyratory movement of said eccentrics and said connecting rods; an outlet manifold one each said pump having an inlet connected to the pump outlet and an outlet, an adjustable pressure responsive switch on one of said manifolds responsive to the pressure of the liquid flowing through said manifold, an electric circuit connected to said clutch including said switch and responsive thereto to cause said pumps to start and stop operating as a function of pressure, said switch being operative to activate and deactivate said clutch for causing said pumps to stop operating when the liquid pressure exceeds a preselected pressure and for causing said pumps to start operating when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond to any selected pressure over a range of pressures.

Claim 4

In a liquid pumping system for plural component airless spray gun means wherein at least two liquids are to be supplied to the gun means under substantially uniform pressures in the range of up to 3000 pounds per square inch and the gun means is intermittently turned off and on thereby tending to cause fluctuations in the liquid pressures at the gun, a pump and operating mechanism therefor comprising, in combination, a pair of double-acting positive displacement pumps each having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of each of said pump cylinders having a cylinder therein aligned with the respective pump cylinder, a crosshead reciprocably and guidably mounted in each said crosshead cylinder and connected to the upper end of the respective piston rod, a connecting rod pivotally connected at its lower end to each of said crossheads; a high-speed electric motor having a drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft and including an electric clutch; said gear train having a pair of output shafts each including an eccentric pivotally connected to the upper end of a respective one of said connecting rods for positively interconnecting said motor and said pistons for reciprocating said pistons in said cylinders; said crossheads isolating said pumps and said pistons and piston rods from the gyratory movement of said eccentrics and said connecting rods; an outlet manifold one each said pump having an inlet connected to the pump outlet and an outlet, an adjustable pressure responsive switch on one of said manifolds responsive to the pressure of the liquid flowing through said manifold, an electric circuit connected to said clutch including said switch and responsive thereto to cause said pumps to start and stop operating as a function of pressure, said switch being operative to activate and deactivate said clutch for causing said pumps to stop operating when the liquid pressure exceeds a preselected pressure and for causing said pumps to start operating when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond to any selected pressure over a range of pressures.

Claim 5

A liquid pump system as set forth in claim 2 wherein at least one of said pumps is exchangeable with other pumps of different volumetric capacities to vary the ratio between the liquids pumped by the two pumps.

Claim 6

A liquid pump and operating mechanism therefor comprising, in combination, a double-acting positive displacement pump having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of said pump cylinder having a cylinder therein aligned with said pump cylinder, a crosshead reciprocably and guidably mounted in said crosshead cylinder and connected to the upper end of said piston rod, and a connecting rod pivotally connected at its lower end to said crosshead; a high-speed electric motor having a drive shaft; an electrically operated clutch coupled to said drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft through said clutch and having an output shaft including an eccentric pivotally connected to the upper end of said connecting rod for positively interconnecting said motor and said piston for reciprocating said piston in said cylinder; said crosshead isolating said pump and said piston and piston rod from gyratory movement of said eccentric and said connecting rod; an outlet manifold having an inlet connected to said pump outlet and an outlet, an adjustable pressure responsive switch on said manifold responsive to the pressure of the liquid flowing through said manifold, an electric circuit connected to said clutch including said switch and responsive to said switch for disengaging said clutch when the liquid pressure exceeds a preselected pressure and for engaging said clutch when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond

Claim 7

A liquid pump and operating mechanism therefor comprising, in combination, a double-acting positive displacement pump having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of said pump cylinder having a cylinder therein aligned with said pump cylinder, a crosshead reciprocably and guidably mounted in said crosshead cylinder and connected to the upper end of said piston rod, and a connecting rod pivotally connected at its lower end to said crosshead; a high-speed electric motor having a drive shaft; an electrically operated clutch coupled to said drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft through said clutch and having an output shaft including an eccentric pivotally connected to the upper end of said connecting rod for positively interconnecting said motor and said piston for reciprocating said piston in said cylinder; said crosshead isolating said pump and said piston and piston rod from gyratory movement of said eccentric and said connecting rod; an outlet manifold having an inlet connected to said pump outlet and an outlet, an adjustable pressure responsive switch on said manifold responsive to the pressure of the liquid flowing through said manifold, an electric circuit connected to said clutch including said switch and responsive to said switch for disengaging said clutch when the liquid pressure exceeds a preselected pressure and for engaging said clutch when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond

Claim 8

A pump as set forth in claim 4 including a frame, said motor being mounted horizontally on said frame, a gear train housing mounted on the housing of said motor and enclosing said gear train, said crosshead housing being mounted on said gear train housing and enclosing said eccentric and said connecting rod, the cylinder of said pump being mounted vertically on and extending downward from said crosshead housing, said

Claim 9

The pump according to claim 4 wherein said clutch comprises a housing, a magnetic coil in said housing energized by said switch means, a rotor in said housing connected to said gear train, an armature connected to the drive shaft of said motor and rotatable therewith, said armature being axially movable on said drive shaft and attracted to said rotor upon

Claim 10

In a liquid pumping system for an airless spray gun wherein liquid is to be supplied to the gun under substantially uniform pressure in the range of up to 3000 pounds per square inch and the gun is intermittently turned off and on thereby tending to cause fluctuations in the liquid pressure at the gun, a pump and operating mechanism therefor comprising, in combination, a double-acting positive displacement pump having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of said pump cylinder having a cylinder therein aligned with said pump cylinder, a crosshead reciprocably and guidably mounted in said crosshead cylinder and connected to the upper end of said piston rod, and a connecting rod pivotally connected at its lower end to said crosshead; a high-speed electric motor having a drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft and having an output shaft including an eccentric pivotally connected to the upper end of said connecting rod for positively interconnecting said motor and said piston for reciprocating said piston in said cylinder; said crosshead isolating said pump and said piston and piston rod from the gyratory movement of said eccentric and said connecting rod; an outlet manifold having an inlet connected to said pump outlet and an outlet for flow therethrough of the pumped liquid; an adjustable pressure responsive switch on said manifold responsive to the pressure of the liquid flowing through said manifold, said switch including a housing having an inlet and an outlet connected in series with the pump outlet for continuous flow therethrough of the pumped liquid, and a flexible diaphragm in said housing for coupling the switch to the hydraulic pressure of the liquid in said housing but physically isolating the switch from contact with the pumped liquid; an electric circuit including said switch and responsive thereto to cause said pump to start and stop operating as a function of pressure for causing said pump to stop operating when the liquid pressure exceeds a preselected pressure and for causing said pump to start operating when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond to any selected pressure over a range of pressures.

Claim 11

In a liquid pumping system for an airless spray gun wherein liquid is to be supplied to the gun under substantially uniform pressure in the range of up to 3000 pounds per square inch and the gun is intermittently turned off and on thereby tending to cause fluctuations in the liquid pressure at the gun, a pump and operating mechanism therefor comprising, in combination, a double-acting positive displacement pump having a cylinder with an inlet at its lower end and an outlet adjacent its upper end, a piston reciprocable in said cylinder between said inlet and said outlet, a piston rod connected to and reciprocable with said piston extending from the upper end of said cylinder, a passage through said piston, and check valves in said inlet and said passage, said piston and piston rod being proportioned to displace half the volume of said cylinder whereby said cylinder is filled with liquid on alternate strokes of said piston and one half of a cylinder full of liquid is discharged from said outlet on each stroke of said piston; a crosshead housing at the upper end of said pump cylinder having a cylinder therein aligned with said pump cylinder, a crosshead reciprocably and guidably mounted in said crosshead cylinder and connected to the upper end of said piston rod, and a connecting rod pivotally connected at its lower end to said crosshead; a high-speed electric motor having a drive shaft; a speed-reducing power-multiplying gear train connected to said drive shaft and having an output shaft including an eccentric pivotally connected to the upper end of said connecting rod for positively interconnecting said motor and said piston for reciprocating said piston in said cylinder; said crosshead isolating said pump and said piston and piston rod from the gyratory movement of said eccentric and said connecting rod; an outlet manifold having an inlet connected to said pump outlet and an outlet for flow therethrough of the pumped liquid; an adjustable pressure responsive switch on said manifold responsive to the pressure of the liquid flowing through said manifold, said switch including a housing having an inlet and an outlet connected in series with the pump outlet for continuous flow therethrough of the pumped liquid, and a flexible diaphragm in said housing for coupling the switch to the hydraulic pressure of the liquid in said housing but physically isolating the switch from contact with the pumped liquid; an electric circuit including said switch and responsive thereto to cause said pump to start and stop operating as a function of pressure for causing said pump to stop operating when the liquid pressure exceeds a preselected pressure and for causing said pump to start operating when the liquid pressure falls below said preselected pressure, and means for adjusting said switch to respond to any selected pressure over a range of pressures.