Pulseless piston pump
First Claim
1. A fluid pump for providing substantially pulseless output comprising;
- a plurality of piston-cylinder combinations;
cam means for driving each said piston in each said cylinder, said cam means driving each said piston in each said cylinder in a reciprocating motion alternating between intake strokes and pumping strokes, said intake strokes and said pumping strokes being divided by a changeover point, said cam means driving said pistons such that at least one said piston is in said pumping stroke at all times and the sum of the velocities of said pistons in said pumping strokes is substantially constant at any given speed of said cam means;
a housing;
a high-pressure seal between said piston and said cylinder for sealing material to be pumped, said piston remaining in contact with said seal at all times;
a sealing diaphragm attached to said housing and said piston intermediate said high pressure seal and said cam means and forming a chamber therebetween and constructed to contain any material that might leak past said high pressure seal and as a barrier between the material to be pumped and the environment, said chamber being sealed from the environment; and
inlet check valves, said cam means increasing said velocity sum relative to said constant prior to said changeover point to create a compensating motion overlap so as to compensate for the nonlinearity of pump output during seating of said check valves.
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Accused Products
Abstract
A multiple piston cylinder reciprocating pump is provided with a cam drive such that the sum of the velocities during the pumping strokes of all of the cylinders is generally constant. The leak free design is provided by utilizing a diaphragm attached to the piston between the main seal assembly and the cam. A flow through intake design is provided which flows incoming material around the piston between the diaphragm and the main seal to prevent the build-up and hardening of material on the piston and in the seal area. The intake and exhaust passages are arranged such that air pockets cannot be formed and any air bubbles which find their way into the pump will rise upwardly out of the pump without restriction.
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Citations
16 Claims
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1. A fluid pump for providing substantially pulseless output comprising;
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a plurality of piston-cylinder combinations; cam means for driving each said piston in each said cylinder, said cam means driving each said piston in each said cylinder in a reciprocating motion alternating between intake strokes and pumping strokes, said intake strokes and said pumping strokes being divided by a changeover point, said cam means driving said pistons such that at least one said piston is in said pumping stroke at all times and the sum of the velocities of said pistons in said pumping strokes is substantially constant at any given speed of said cam means; a housing; a high-pressure seal between said piston and said cylinder for sealing material to be pumped, said piston remaining in contact with said seal at all times; a sealing diaphragm attached to said housing and said piston intermediate said high pressure seal and said cam means and forming a chamber therebetween and constructed to contain any material that might leak past said high pressure seal and as a barrier between the material to be pumped and the environment, said chamber being sealed from the environment; and inlet check valves, said cam means increasing said velocity sum relative to said constant prior to said changeover point to create a compensating motion overlap so as to compensate for the nonlinearity of pump output during seating of said check valves. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 14, 15, 16)
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9. A fluid pump for providing substantially pulseless output comprising;
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a plurality of piston-cylinder combinations; cam means for driving each said piston in each said cylinder, said cam means driving each said piston in each said cylinder in a reciprocating motion alternating between intake strokes and pumping strokes, said cam means driving said pistons such that at least one said piston is in said pumping stroke at all times and the sum of the velocities of said pistons in said pumping strokes is substantially constant at any given speed of said cam means; a housing; a high-pressure seal between said piston and said cylinder for sealing material to be pumped, said piston remaining in contact with said seal at all times; and a sealing diaphragm attached to said housing and said piston intermediate said high pressure seal and said cam means and to contain any material that might leak past said high pressure seal and as a barrier between the material to be pumped and the environment a flushing inlet passage leading from a source of material to be pumped around said piston intermediate said diaphragm and said high pressure seal to minimize stagnation and prevent buildup or solidification of pumped material on said piston wherein said cylinder, said piston and said high pressure seal form a pumping chamber and said pump further comprises a main inlet passage connecting said flushing inlet passage and said pumping chamber. - View Dependent Claims (10, 11, 12, 13)
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Specification