US3217761A

US3217761A - Automatic dilutor

Info

Publication number: US3217761A
Application number: US300276A
Authority: US
Inventors: Justin J Shapiro
Original assignee: LABINDUSTRIES
Current assignee: LABINDUSTRIES
Priority date: 1963-08-06
Filing date: 1963-08-06
Publication date: 1965-11-16
Anticipated expiration: 1982-11-16

Description

' Nov. 16, 1965 J. J. SHAPIRO 3,217,761

AUTOMATIC DILUTOR Filed Aug. 6, 19 3 65 l-Ill! h 26 1E ll llll I I 1 w nnumuumm j 1 36 3 4 I! I 2/) H i 1 L f I i 1 5 jug? I I I 1, 37 I I 7, '3 I as l FIE .3 .62

INVENTOR JUST/N J SHAP o ATTORNEY United States Patent 3,217,761 AUTOMATIC DILUTOR Justin J. Shapiro, Labindustn'es, 1740 University Ave., Berkeley, Calif. Filed Aug. 6, 1963, Ser. No. 300,276 6 Claims. (Cl. 14127) This invention relates to liquid dispensing devices, and more particularly to a device for performing precise dilutions.

A main object of the invention is to provide a novel and improved device for withdrawing a precise amount of a liquid reagent from a supply vessel and then transferring this precise amount of reagent to another vessel together with a precise volume of a diluent liquid while at the same time washing out the delivery portion of the device with the diluent.

A further object of the invention is to provide an improved device for performing precise dilutions of one liquid with another, said device being simple in construction, being easy to operate, and being especially useful for performing precision repetitive dilutions.

A still further object of the invention is to provide an improved automatic dilutor for performing precise dilutions of one liquid with another, said dilutor being of a type which aspirates a precise amount of reagent from a supply vessel and transfers this reagent to another vessel together with a precise volume of a diluent liquid, the device being economical to manufacture, being easy to check visually for proper operation, and being easy to clean.

A still further object of the invention is to provide an improved automatic precision dilutor adapted to be mounted on a bottle or similar vessel containing diluent liquid, having means to withdraw a precise amount of reagent from a reagent supply vessel, and having means to transfer the reagent, together with a precise amount of diluent liquid to a receiving vessel, the device being provided with means to admit filtered air into the top of the first-named bottle or vessel while diluent liquid is being drawn therefrom and having weighted valve means to isolate the device from the contents of the first-named bottle or vessel while the reagent is being drawn into the device from the reagent supply vessel.

A still further object of the invention is to provide an improved automatic precision dilutor adapted to be mounted on a vessel containing diluent liquid, having means to draw a precisely measured amount of reagent from a reagent supply vessel and having means to transfer the reagent, together with a precisely measured amount of diluent to a receiving vessel, the device being arranged to provide an automatically air-free system by the provision of means to drive air out of the system ahead of the reagent.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein: I FIGURE 1 is a vertical cross-sectional view, partly broken away, showing an improved automatic dilutor according to the present invention mounted on a diluent bottle.

FIGURE 2 is an enlarged horizontal cross-sectional view taken substantially on the line 22 of FIGURE 1.

FIGURE 3 is an enlarged side elevational view of the liquid-filled weight member employed to hold the diluent valve of the device of FIGURE 1 closed while reagent is being aspirated into the device.

Referring to the drawings, 11 generally designates an improved precision dilutor constructed in accordance with the present invention. The dilutor 11 comprises a main tubular barrel 12, of relatively large diameter, of glass,

or other suitable transparent material, the lower end portion of the barrel being adapted to be sealingly mounted in the neck portion 13 of a bottle 14, or similar vessel, containing diluent liquid. Thus, said lower barrel portion may be provided with an integral circumferential sealing rib 15 and an internally threaded annular cap 16 may be threadedly engaged with the externally threaded upper portion 18 of neck 13, the rib 15 being received in the cap 16, and resilient deformable

annular sealing rings

19 and 20 being provided on the barrel portion immediately above and below said rib, as shown in FIGURE 1.

Sealingly and slidably mounted in the upper portion of barrel 12 is a diluent dispensing plunger 21 provided at its top end with the square head flange 22, off-center relative to the axis of the plunger, and engageable with the outwardly projecting top flange or rim 23 of barrel 12 when the plunger is in its lower-most position, as shown in FIGURE 1. A depending rod 24 is rigidly secured to the outermost corner portion of square flange 22, and adjustably mounted on rod 24 is a flanged stop collar 25 which is engageable with flange 23 to limit upward movement of plunger 21. Collar 25 is provided with a clamping screw 27 to lock it in adjusted position on rod 24. Collar 25 is provided with the base flange 26 which extends adjacent a diluent volume scale 28 inscribed on barrel 12, to indicate the volumetric setting of the diluent plunger 21. Thus, the collar 25 may be adjusted on the rod 24 to deliver a predetermined amount of diluent per stroke from the diluent vessel 14, said volume being indicated on scale 28 by flange 26 with the plunger in its fully lowered position, as shown in FIGURE 1.

The plunger chamber, shown at 29, communicates with a reduced tubular conduit 30 formed integrally with barrel 12 and extending downwardly therefrom. The lower portion of the conduit is further reduced, as shown at 31, and an enlarged conduit portion 32 is provided between the reduced lower conduit portion 31 and the upper conduit portion 30. The enlarged conduit portion 32 is formed with a frusto-conical seat 33 receiving a movable valve ball 34, said valve ball being biased downwardly by an elongated sealed vessel 35 substantially filled with heavy liquid material 60, such as mercury, or the like. The vessel 35 is loosely and slidably disposed in conduit portion 32, allowing free flow of liquid therepast. Said vessel is formed with the upper and lower

annular guide ribs

36 and 37, and has a concave bottom recess 38 in which the top portion of ball 34 is receivable. Upward movement of the weighted vessel 35 is limited by the provision of an inwardly projecting integral stop lug 39 formed in the conduit portion 32 and being engageable with the top wall portion 40 of the hollow vessel 35.

As will be presently explained, the purpose of the weighted vessel 35 is to keep the ball 34 seated in the frusto-conical seat 33 when reagent is being aspirated into the device for subsequent delivery and dilution.

A downwardly and outwardly inclined air inlet tube 41 is integrally formed in the lower portion of barrel 12 immediately below the junction of the chamber 29 with the reduced conduit portion 30. The tube 41 is adapted to receive a suitable filter device 42 to filter the air drawn into the diluent vessel 14 when diluent is dispensed therefrom, whereby to protect the diluent in the vessel 14 from contamination.

A horizontal branch tube 43, formed integrally with barrel 12 and communicating with the chamber 29, originates at the level of the bottom end of plunger 21 When said plunger is in its lowermost position. Integrally formed with and rising vertically from the outer end of branch tube 43 is the reagent aspirating barrel 44, of relatively small diameter, containing the aspirating plunger 45. Plunger 45 is formed with the top operating flange 65 to which is rigidly secured the depending rod 46. Said rod 46 is provided with the adjustable stop collar 47 engageable with the top rim flange 48 of barrel 44 to limit the upward extension of plunger 45. Collar 47 has a locking screw 49 and a bottom indicator flange 50. A reagent intake volumetric scale 51 is inscribed on barrel 44 and the intake volume may be preset by securing the collar 47 on the rod 46 with the plunger 45 fully lowered, namely, with flange 65 engaging ri-m 48, the preset volume being indicated by flange St} on scale 51.

Integrally formed with the lower portion of barrel 44 is the laterally directed conduit portion 52 having the depending tip portion 53. The origin of the laterally directed conduit 52 is at the level of the bottom end of plunger 45 when said plunger is fully lowered. Below the conduit portion 52 barrel 44 is formed with a frusto conical ball seat 54 in which is movably disposed a seal ing valve ball 55. Upward movement of valve ball 55 is limited by an inwardly projecting stop lug 55 integrally formed in barrel 44 just below the connection to laterally extending conduit portion 52.

The contained volume of the conduit portion 52 and the tip portion 53 is preferably greater than the maximum capacity of the aspirating syringe defined by barrel 44 and plunger 45. This preferred volume relationship prevents the aspirated reagent from ever reaching the aspirating plunger 45.

In operation, with the plunger 45 fully lowered in barrel 44 the top 52 is immersed in a receptacle containing the reagent to be dispensed and diluted. The reagent is aspirated into the tip and the conduit portion 52 by raising the plunger 45 until collar 47 engages the rim flange 48, thus drawing the preset volume of reagent into the tip 53 and conduit portion 52. The weighted member 35 holds the ball 34 seated during this step. The reagent vessel is then removed, and the intended receiving vessel is then placed below the tip 53. The aspirating plunger 45 is then allowed to fall and is lowered to expel the reagent into the receiving vessel. The plunger 21 is then raised gently until collar 24 engages rim flange 23, drawing the preset volume of diluent from the vessel 14. After a short time, during which valve ball 34 reseats, the plunger 21 is gently depressed all the way, dispensing the diluent into the receiving vessel and at the same time washing out the outlet tip 53.

The upward stroke of the plunger 21 causes the diluent to flow upwardly past the weighted valve ball 34, the weight of the member 35 being overcome because it is the only valve which can open under the relatively large pressure differential created by the vacuum induced by the relatively large-diameter plunger 21. On the downward stroke of plunger 21 the diluent is forced past the valve ball 55, and the preset quantity of diluent is forced through conduit portion 52 and tip 53 into the receiving vessel, at the same time flushing out said conduit portion and tip.

The valve ball 34 does not open when aspirating plunger 45 is raised because of the combination of the hydrostatic head of liquid above the surface of the diluent in vessel 14 and the weight of the member 35 acting downwardly thereon.

Unless the downward stroke of the plunger 21 is particularly forceful, the plunger 45 will not rise. If the plunger 45 should rise, it may be subsequently depressed to obtain the delivery of the desired amount of diluent.

For large aspirated volumes of reagent, tubular extensions may be attached to the tip 53 in any suitable manner, for example, by means of plastic coupling sleeves.

It will be apparent that because of the geometry of the parts, namely, the provision of the diluent pumping plunger 21 arranged in the manner above described, air is automatically removed by pumping the plunger, the air being driven out of the system ahead of the reagent. The weighted valve member 34 provides complete isolation of the diluent inlet valve assembly from the reagent aspirating portion of the apparatus.

While a specific embodiment of a precision dilutor has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. A reagent dilutor comprising an upstanding diluent barrel having a reduced tubular lower diluent intake portion, upwardly opening check valve means in said intake portion, means to sealingly secure the lower end portion of said barrel in a diluent container, air intake means in said lower end portion, a diluent dispensing plunger in the upper portion of said barrel, means adjustably limiting the upward extension of said diluent dispensing plunger, a branch conduit connected to said barrel above said diluent intake portion, an upstanding reagent aspirating barrel connected to said branch conduit, upwardly opening check valve means in the lower portion of said reagent aspirating barrel, a reagent aspirating plunger in the upper portion of said reagent aspirating barrel, means adjustably limiting the upward extension of said reagent aspirating plunger, and a conduit member having a depending tip connected to the lower portion of said reagent aspirating barrel above said last-named check valve means, the volume of said conduit member and tip being larger than the volume of said aspirating barrel.

2. A reagent dilutor comprising an upstanding diluent barrel having a reduced tubular lower diluent intake portion, upwardly opening check valve means in said intake portion, weight means acting on said check valve means to bias it against opening, means to sealingly secure the lower end portion of said barrel in a diluent container, air intake means in said lower end portion, a diluent dispensing plunger in the upper portion of said barrel, a branch conduit connected to said barrel above said diluent intake portion, an upstanding reagent aspirating barrel connected to said branch conduit, upwardly opening check valve means in the lower portion of said reagent aspirating barrel, a reagent aspirating plunger in the upper portion of said reagent aspirating barrel, and a depending conduit member connected to the lower portion of said reagent aspirating barrel above said last-named check valve means.

3. A reagent dilutor comprising an upstanding relatively large-diameter diluent barrel having a reduced depending tubular lower diluent intake portion, upwardly opening check valve means in said intake portion, weight means acting on said check valve means to bias it against opening, means to sealingly secure the lower end portion of said barrel in a diluent container, air intake means in said lower end portion, a diluent dispensing plunger in the upper portion of said barrel, a branch conduit connected to said barrel above said diluent intake portion, an upstanding relatively small-diameter reagent aspirating barrel connected to said branch conduit, upwardly opening check valve means in the lower portion of said reagent aspirating barrel, a reagent aspirating plunger in the upper portion of said reagent aspirating barrel, and a depending conduit member connected to the lower portion of said reagent aspirating barrel above said lastnamed check valve means.

4. A reagent dilutor comprising an upstanding relatively large-diameter diluent barrel having a reduced depending tubular lower diluent intake portion, an upwardly opening ball check valve in said intake portion, a weight member engaged on said ball check valve to bias it against opening, means to sealingly secure the lower end portion of said barrel in a diluent container, air intake means in said lower end portion, a diluent dispensing plunger in the upper portion of said barrel, a branch conduit connected to :said barrel above said diluent intake portion, an upstanding relatively small-diameter reagent aspirating barrel connected to said branch conduit, up-

wardly opening check valve means in the lower portion of said reagent aspirating barrel, a reagent aspirating plunger in the upper portion of said reagent aspirating barrel, and a depending conduit member connected to the lower portion of said reagent aspirating barrel above said last-named check valve means.

5. The structure of claim 4, and wherein said weight member comprises a hollow vessel containing a relatively heavy liquid.

6. A reagent dilutor comprising an upstanding relatively large-diameter diluent barrel having a reduced depending tubular lower diluent intake portion, an upwardly opening ball check valve in said intake portion, a Weight member engaged on said ball check valve to bias it against opening, said weight member comprising a hollow vessel containing a relatively heavy liquid, means to sealingly secure the lower end portion of said barrel in a diluent container, air intake means in said lower end portion, a diluent dispensing plunger in the upper portion of said barrel, means adjustably limiting the upward extension of said diluent dispensing plunger, a branch conduit connected to said barrel above said diluent intake portion, an upstanding relatively small-diameter reagent aspirating barrel connected to said branch conduit, upwardly opening check valve means in the lower portion of said reagent aspirating barrel, a reagent aspirating plunger in the upper portion of said reagent aspirating barrel, means adjustably limiting the upward extension of said reagent aspirating plunger, and a conduit member having a depending tip connected to the lower portion of said reagent aspirating barrel above said last-named check valve means, the volume of said conduit member and tip being larger than the volume of said aspirating barrel.

References Cited by the Examiner UNITED STATES PATENTS 1,013,448 1/1912 Rose 128213 1,138,749 5/1915 Green 141-105 1,269,348 6/1918 Warren l4127 2,910,981 11/1959 Wilson et al. 218214 FOREIGN PATENTS 907,262 3/ 1954 Germany.

LAVERNE D. GEIGER, Primary Examiner.