PROGRAMMED LIQUID DELIVERY SYSTEM

• US 3,749,285 A
• Filed: 09/13/1971
• Issued: 07/31/1973
• Est. Priority Date: 09/13/1971
• Status: Expired due to Term

• Current Assignee: Haemonetics Corporation
• Original Assignee: Allen Latham Jr
• Inventors: Latham, Allen Jr.
• Primary Examiner(s): Tollberg, Stanley H.
• Application Number:
  US05/179,869
• Time in Patent Office: 687 Days
• Field of Search: 177/225 222/58,214 128/214E,214F,DIG.13
• US Class Current: 222/58
• CPC Class Codes: A61M 5/16845 by weight
• CPC Class Codes: G01F 3/02 with measuring chambers which expand or contract during measurement
• CPC Class Codes: G01G 19/32 using two or more weighing apparatus

Abstract

Fluid dispensing program method and apparatus designed to be preset to deliver a predetermined weight of one or more liquids in sequence. When the exact preset weight of liquid is delivered from any one liquid reservoir a sensing means is triggered by the upward motion of a weighing means responsive to a decrease in weight from which the reservoir is suspended. The sensing means directs a signal to a stepping switch which effects a closing off of liquid flow and the actuation of the next step in the protocol being followed. Rates of liquid flow may be controlled if desired. The system is particularly suitable for controlling amounts of different liquids to a centrifuge during deglycerolization of red blood cells.

Claims

1. A programmed liquid delivery system capable of delivering predetermined quantities of liquids in sequence according to a predetermined protocol, comprising in combination a. a plurality of liquid reservoir means each containing a liquid, each of said reservoir means including discharge means and being adapted for free suspension;

b. separate tubing means connected to each of said discharge means of said liquid reservoir means;

c. separate weighing means associated with each of said reservoir means and arranged to effect the free suspension of said reservoir means and to be responsive to a decrease in weight of said associated reservoir means as said liquid is withdrawn therefrom, said decrease in weight being a measure of the quantity of said liquid withdrawn from said associated reservoir means;

d. separate sensing means, actuatable by each of said weighing means, adapted to sense the withdrawal of at least one in a series of predetermined quantities of said liquid from its associated reservoir means and to generate a switching signal when each predetermined quantity has been withdrawn;

e. stepping switch means adapted to receive said switching signals in sequence from said separate sensing means and to generate fluid flow control signals; and

f. separate fluid flow rate control means associated with each of said tubing means and responsive to said fluid flow control signals, whereby the flow of said liquid in each of said tubing means is directly controlled by the quantity of said liquid withdrawn from said associated liquid reservoir means.

2. a vertically oriented rod freely movable within said frame means, said rod having attachment means on its lower end adapted to effect the free suspension of said liquid reservoir means,

3. A programmed liquid delivery system in accordance with claim 1 wherein each of said weighing means comprises a tension spring, the upper end of which is anchored to fixed support meaNs and the lower end of which is anchored to a freely moving vertically oriented rod arranged to effect said free suspension of said reservoir means.

4. pointer means affixed to said rod,

5. A programmed liquid delivery system in accordance with claim 4 wherein said switch means comprises a reed switch and said switch actuating means comprises a magnet.

6. calibrated scale means parallel to said rod, spaced therefrom and slotted to permit said pointer means to move freely along the face of said scale means to indicate positions thereon indicative of the weight of said liquid reservoir means,

7. A programmed liquid delivery system in accordance with claim 1 wherein each of said fluid flow rate control means comprises pinch clamp means.

8. A programmed liquid delivery system in accordance with claim 7 wherein one or more of said pinch clamp means comprises first overcenter pivot arm means and associated adjustable platen means adapted to control the cross sectional area of said tubing means and thereby to control the rate of fluid flow through said tubing means and second overcenter pivot arm means and associated fixed platen means adapted to open and close said tubing means to liquid flow.

9. A programmed liquid delivery system capable of delivering a predetermined quantity of a liquid, comprising in combination a. a plurality of liquid reservoir means each containing a liquid, each of said reservoir means including discharge means and being adapted for free suspension;

b. separate tubing means connected to each of said discharge means of said liquid reservoir means;

c. separate liquid weight measuring means associated with each of said liquid reservoir means, each of said liquid reservoir means, each of said liquid weight measuring means comprising in combination

10. A programmed liquid delivery system in accordance with claim 9 wherein one or more of said liquid weight measuring means has a plurality of said weight sensing switch means actuatable in sequence by said weight sensing switch actuator means, the actuatIon of each of said weight sensing switch means giving rise to a separate electrical signal;

and wherein said fluid flow control means associated with the tubing means connected to the liquid reservoir means with which said liquid weight measuring means is associated comprises separate pinch clamp means for each of said weight sensing switching means whereby the rate of fluid flow in said tubing may be varied according to a predetermined protocol.