Volumetric pump tube reshaper and method
First Claim
1. Apparatus for compressing and shaping a flexible tube, comprising:
- a. single plunger means, mounted to move bidirectionally along a reciprocation axis, for periodically alternately compressing a segment of the flexible tube to displace a fluid from an interior passage disposed within the flexible tube, and then allowing the flexible tube to expand to at least a partially uncompressed condition;
b. drive means, for periodically driving the plunger means to move along the reciprocation axis; and
c. tube reshaper means, actuated by the motion of the plunger means, for applying a reshaping force transversely against substantially the same segment of the flexible tube that was compressed, the reshaping force tending to expand the interior passage to a maximum desired volume.
1 Assignment
0 Petitions
Accused Products
Abstract
A volumetric pump and method for displacing a predetermined quantity of fluid at a predefined cracking pressure, independent of supply and output pressures. The volumetric pump (30) includes an inlet cracking valve (46), an outlet cracking valve (52), and a plunger (48)for displacing fluid from a pumping portion (34b) of flexible tubing (34) that extends through the volumetric pump. The pumping portion of the flexible tube fills with liquid when the inlet cracking valve is fully opened and is urged to expand by jaws (236) on pivotally-mounted arms (234). The arms are forced to pivot, as tubing reshaper rollers (160), disposed on the plunger, roll along the inner surface (232) of each arm. During a pumpback-pressurization segment of the pumping cycle, the inlet cracking valve applies a cracking force to the flexible tubing, while the plunger compresses the pumping portion of the flexible tubing sufficiently to develop a cracking pressure that displaces excess fluid back through the inlet cracking valve toward a container (32). After the excess fluid has been forced from the pumping portion of the flexible tubing, a pumping segment of the cycle begins, wherein the inlet cracking valve closes fully and the outlet cracking valve applies a cracking force to compress the flexible tubing. Fluid is then forced by the plunger from the pumping portion of the flexible tubing into a distal portion (34c). The volumetric pump compensates for variations in elasticity of the flexible tubing that would otherwise cause variations in the cracking pressure, using balance blocks (42 and 58).
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Citations
15 Claims
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1. Apparatus for compressing and shaping a flexible tube, comprising:
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a. single plunger means, mounted to move bidirectionally along a reciprocation axis, for periodically alternately compressing a segment of the flexible tube to displace a fluid from an interior passage disposed within the flexible tube, and then allowing the flexible tube to expand to at least a partially uncompressed condition; b. drive means, for periodically driving the plunger means to move along the reciprocation axis; and c. tube reshaper means, actuated by the motion of the plunger means, for applying a reshaping force transversely against substantially the same segment of the flexible tube that was compressed, the reshaping force tending to expand the interior passage to a maximum desired volume. - View Dependent Claims (2, 3, 4, 5)
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6. A method of compressing and reshaping a flexible tube to repeatedly displace a desired volume of fluid from an interior passage disposed within the flexible tube, comprising the steps of:
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a. forcing a longitudinally extending surface of a single plunger, which is mounted to move bidirectionally along a reciprocation axis, against a segment of the tube to compress the segment of the tube, the longitudinally extending surface being substantially parallel to the segment of the tube being compressed; b. retracting the plunger away from the tube to remove the compressive force on the tube along the reciprocation axis; and c. reshaping the flexible tube by forcing at least one reshaper jaw against at least one side of the tube in a direction substantially perpendicular to the reciprocation axis along substantially the same segment of the tube to which the compressive force was applied, such that the interior passage of the tube expands. - View Dependent Claims (7)
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8. An apparatus for repeatedly compressing and shaping a flexible tube having an interior passage, comprising:
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a. a frame for holding a portion of the flexible tube; b. a single plunger coupled to the frame so as to be disposed opposite at least one side of a segment of the flexible tube; c. plunger drive means coupled to the plunger for repeatedly moving the plunger into and out of compression against a segment of the flexible tube; d. at least one jaw member disposed along substantially the same segment of the flexible tube as the plunger, the at least one jaw member being positioned to apply a compressive force to at least one side of the flexible tube in a direction generally transverse to the direction of plunger movement; and e. jaw member drive means coupled to the at least one jaw member for repeatedly moving the at least one jaw member into and out of compression against at least one side of the same segment of the flexible tube, the at least one jaw member expanding the interior passage when in a position of compression with the tube. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A single-plunger fluid pump for repeatably compressing and shaping a flexible tube having an interior passage, comprising:
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a. a frame for holding a portion of the flexible tube; b. a single plunger coupled to the frame so as to be disposed opposite at least one side of a segment of the flexible tube, said plunger having a longitudinal surface; c. plunger drive means coupled to the plunger for repeatably moving the longitudinal surface of the plunger into and out of compression against a segment of the flexible tube; d. at least one jaw member disposed along substantially the same segment of the flexible tube as the longitudinal surface of the plunger, said at least one jaw member being positioned to apply a compressive force to at least one side of the flexible tube in a direction generally transverse to the direction of plunger movement; and e. jaw member drive means coupled to said at least one jaw member for repeatedly moving said at least one jaw member into and out of compression against at least one side of the same segment of the flexible tube, said at least one jaw member expanding the interior passage when in a position to compress the tube. - View Dependent Claims (15)
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Specification