Proportioning pump

• US 5,170,912 A
• Filed: 09/07/1990
• Issued: 12/15/1992
• Est. Priority Date: 09/07/1990
• Status: Expired due to Term

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: Benjamin R. Du
• Inventors: Du, Benjamin R.
• Primary Examiner(s): Shaver, Kevin P.
• Application Number:
  US07/579,888
• Time in Patent Office: 830 Days
• Field of Search: 222/129.1-129.2, 222/135-137, 222/134, 222/148, 222/334, 222/249, 222/250, 222/288, 222/335, 222/336, 417/393, 239/113, 138/30
• US Class Current: 222/129.2
• CPC Class Codes: B67D 1/105 for two or more components

Abstract

A proportioning pump has a first piston and cylinder, a second piston and cylinder, a shaft connecting the first and second pistons, a spring for biasing the first and second pistons in a first position, a shuttle valve for controlling flow through the first cylinder, and two check valves for controlling flow through the second cylinder. The proportioning pump is used to dispense a predetermined ratio of two fluids. A pressurized first fluid fills the first cylinder and forces the first piston to move to a second position. The motion of the first piston is communicated to the second piston via the shaft. Movement of the second piston draws the second fluid through a check valve into the second cylinder. When both the first and second cylinders are full the shuttle valve closes the inlet to the first cylinder and opens the outlet. The spring then urges the first and second pistons back to their first positions, thus forcing the two fluids from their respective cylinders. The two check valves prevent reverse flow through the second cylinder. The ratio of the volume of the two fluids being pumped can be varied by changing the second cylinder and piston. An accumulator is used to provide even flow of the carbonated water. The arrangement of the carbonated water and syrup nozzles prevents the buildup of syrup at the nozzle openings, thus insuring that proper flow of both fluids is maintained.

Claims

1. A proportioning pump for delivering a predetermined ratio of two fluids, comprising:

(a) a pressurized fluid-driven, positive displacement motor means for delivering a quantity of a first fluid; and

(b) a positive displacement pump means for delivering a proportional quantity of a second fluid, said positive displacement pump means being removably connectable to and drivable from said positive displacement rotor means via the use of a bayonet connector interface to facilitate the rapid connection and disconnection of said positive displacement motor to said positive displacement pump;

(c) wherein delivery of a quantity of said first fluid by said positive displacement motor means and delivery of a proportional quantity of said second fluid by said positive displacement pump means occurs simultaneously and results in the delivery of substantially constant volumetric proportions of said first and second fluids.

2. The proportioning pump as recited in claim 1 further comprising an accumulator in fluid communication with said positive displacement motor to minimize the pulsations in the flow of the first fluid caused by the pumping action of said positive displacement motor.

3. A proportional pumping system for delivering a predetermined ratio of two fluids, comprising:

(a) a first housing having a first cylinder formed therein and also having an inlet for providing fluid flow into the first cylinder and an outlet for providing fluid flow out of the first cylinder;

(b) a second housing connectable to the first housing, said second housing having a second cylinder formed therein and also having an inlet for providing fluid flow into the second cylinder and an outlet for providing fluid flow out of the second cylinder;

(c) a first piston disposed within the first cylinder, said first piston being reciprocally movable through intake and exhaust strokes within the first cylinder, the first piston moving in response to the flow of a first fluid;

(d) a second piston disposed within the second cylinder, the second piston being reciprocally movable through intake and exhaust strokes within the second cylinder for pumping a second fluid therethrough;

(e) a shaft attached at one end to said first piston and removably attached at the opposite end to said second piston, said shaft causing said first piston and said second piston to reciprocate in unison;

(f) a valve means for controlling fluid flow into and out of the first cylinder comprising;

(i) a shuttle valve disposed within the first cylinder, said shuttle valve for terminating fluid flow out of the first cylinder and permitting fluidflow into the first cylinder when said shuttle valve is in a first position and for terminating fluid flow into the first cylinder and permitting fluid flow out of the first cylinder when said shuttle valve is in a second position;

(ii) a detent means formed upon said first housing;

(iii) a first recess formed in said shuttle valve for cooperating with said detent means to temporarily lock said shuttle valve in the first position;

(iv) a second recess formed in said shuttle valve for cooperating with said detent means to temporarily lock said shuttle valve in the second position;

(v) a first spring disposed within said first cylinder, one end of said first spring moving in response to the motion of said second piston and the opposite end of said spring abutting said shuttle valve, for urging said shuttle valve into its second position when said second piston is in its second position;

(vi) a second spring disposed within said first cylinder, one end of said spring moving in response to the motion of said first piston and the opposite end of said spring abutting said shuttle valve, for urging said shuttle valve into its first position when said first piston is in its first position;

(vii) a valve means for controlling fluid flow into and out of the second cylinder comprising first and second check valves in fluid communication with the second cylinder, said first check valve permitting fluid flow into the second cylinder from said second housing inlet and substantially limiting fluid flow from the second cylinder into the second housing inlet and said second check valve permitting fluid flow out of the second cylinder to the second housing outlet while substantially limiting fluid flow into the second cylinder from the second housing outlet;

(viii) a means for biasing said first and second pistons in an initial position, the initial position being that position in which the first and second cylinders are substantially empty of their respective fluids;

(g) a diaphragm seal attached at its periphery to said first housing for preventing the first fluid from leaking out of the first cylinder;

(h) an O-ring seal disposed in a groove formed about the skirt of said second piston for preventing the second fluid from leaking out of the second cylinder;

(i) a bayonet connector attaching said first housing to said second housing;

(j) a T-slide connector attaching said second piston to said shaft;

(k) an accumulator in fluid communication with the fluid outlet of the first housing for minimizing pulsations in the flow of the first fluid from the first cylinder;

(l) a nozzle in which the first and second fluids are mixed and dispensed;

(m) a first aperture disposed within said nozzle, having a restriction and in fluid communication with the fluid outlet of the first housing;

(n) a second aperture disposed within said nozzle, in fluid communication with the fluid outlet of the second housing; and

(o) a third aperture disposed within said nozzle, in fluid communication with said accumulator and disposed such that fluid sprayed from said third aperture is incident upon said second aperture.

4. A proportioning pump for delivering a predetermined ratio of two fluids, comprising:

(a) a first housing having a first cylinder formed therein and also having an inlet for providing fluid flow into the first cylinder and an outlet for providing fluid flow out of the first cylinder;

(b) a second housing connectable to the first housing, said second housing having a second cylinder formed therein and also having an inlet for providing fluid flow into the second cylinder and an outlet for providing fluid flow out of the second cylinder;

(c) a first piston disposed within the first cylinder, said first piston being reciprocally movable through intake and exhaust strokes within the first cylinder, the first piston moving in response to the flow of a first fluid;

(d) a second piston disposed within the second cylinder, the second piston being reciprocally movably through intake and exhaust strokes within the second cylinder for pumping a second fluid therethrough;

(e) a shaft attached at one end to said first piston and removably attachable at the opposite end to said second piston, said shaft causing said first piston and said second piston to reciprocate in unison;

(f) a valve means for controlling fluid flow into and out of the first cylinder;

(g) a valve means for controlling fluid flow into and out of the second cylinder;

(h) a means for biasing said first and second pistons in an initial position, the initial position being that position in which the first and second cylinders are substantially empty of their respective fluids;

(i) a nozzle in which the first and second fluids are mixed and dispensed;

(j) a first aperture disposed within said nozzle, having a restriction and in fluid communication with the fluid outlet of the first housing;

(k) a second aperture disposed within said nozzle, in fluid communication with the fluid outlet of the second housing; and

(l) a third aperture disposed within said nozzle, in fluid communication with said accumulator and disposed such that fluid sprayed from said third aperture is incident upon said second aperture.

5. The proportioning pump as recited in claim 4 wherein:

(a) said valve means for controlling fluid flow into and out of the first cylinder comprises a shuttle valve for terminating fluid flow out of the first cylinder and permitting fluid flow into the first cylinder when said shuttle valve is in a first position and for terminating fluid flow into the first cylinder and permitting fluid flow out of the first cylinder when said shuttle valve is in a second position; and

(b) said valve means for controlling fluid flow into and out of the second cylinder comprises first and second check valves in fluid communication with the second cylinder, said first check valve permitting fluid flow into the second cylinder from said second housing inlet and substantially limiting fluid flow from the second cylinder into the second housing inlet and said second check valve permitting fluid flow out of the second cylinder to the second housing outlet while substantially limiting fluid flow into the second cylinder from the second housing outlet.

6. The proportioning pump as recited in claim 5 wherein said valve means for controlling fluid flow into and out of the first cylinder further comprises:

(a) a detent means formed upon said first housing;

(b) a first recess formed in said shuttle valve for cooperating with said detent means to temporarily lock said shuttle valve in the first position;

(c) a second recess formed in said shuttle valve for cooperating with said detent means to temporarily lock said shuttle valve in the second position;

(d) a first spring disposed within said first cylinder, one end of said first spring moving in response to the motion of said second piston and the opposite end of said spring abutting said shuttle valve, for urging said shuttle valve into its second position when said second position is in its second position; and

(e) a second spring disposed within said first cylinder one end of said spring moving in response to the motion of said first piston and the opposite end of said spring abutting said shuttle valve, for urging said shuttle valve into its first position when said first piston is in its first position.

7. The proportioning pump as recited in claim 6 further comprising:

(a) a diaphragm seal attached at its periphery to said first housing for preventing the first fluid from leaking out of the first cylinder; and

(b) an O-ring seal disposed in a groove formed about the skirt of said second piston for preventing the second fluid from leaking out of the second cylinder.

8. The proportioning pump as recited in claim 7 wherein said second housing is connected to said first housing with bayonet connectors and wherein said second piston is removably attached to said shaft with a T-slide connector.

9. The proportioning pump as recited in claim 8 further comprising an accumulator in fluid communication with the fluid outlet of the first housing for minimizing pulsations in the flow of the first fluid from the first cylinder.