US3333543A

US3333543A - Metering pump

Info

Publication number: US3333543A
Application number: US419496A
Authority: US
Inventors: Albaut Gaston
Original assignee: Sonal SARL
Current assignee: Sonal SARL
Priority date: 1964-12-18
Filing date: 1964-12-18
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

Aug. 1, 1967 G. ALBAUT 3,333,543 y METERING PUMP Filed Dec. 18, 1964 3 Sheets-Sheet l [NVE/VIVI? Gusta/1 ALBAl/T G. ALBA UT METER ING PUMP Aug. l1

Filed Dec. 18, 1964 5 Sheets-Sheet 3 Gasto);

United States Patent O 3,333,543 METERING PUMP Gaston Albaut, Paris, France, assignor to Societe responsabilite limitee dite Sonal, Argenteuil, Seine-et- Oise, France, a corporation of France Filed Dec. 18, 1964, Ser. No. 419,496 14 Claims. (Cl. 10S-38) The invention concerns a metering pump having a variable and adjustable micro-delivery, capable of delivering a strictly regulated ow of luid, for example from 0.1 cm.3 to 100 cm.3 per hour and even longer. It can be used in all kinds of iields: physics, chemistry, physico-chemical work, biology, medicine land even nuclear energy. It may be constituted in such a manner that the delivered uid of various types come in contact only with speciiic inaterials which can be sterilised lif necessary; these materials may have a mineral, vegetable and animal, metallic or plastic base.

The pump according to the invention has a certain number of features which may be iused separately or in combination.

The driving device for the pump piston is constituted by a synchronous motor provided with a speed reduction box and the output shaft of the reduction box carries an eccentric on which rotates aroller connected to a positive drive for the pump piston.

The eccentric which makes it possible to vary the travel of the piston, i.e., to regulate and obtain the desired delivery, is mounted on a variable-position fork, being for this purpose mounted pivotably and the position of the pivot being geometrically chosen to automatically correct an advance or delay at the opening of the delivery valve in accordance with the amount of the delivery rate and more exactly to correct the instant the piston has reached the top in View of the instant the intake valve opens.

The admission and delivery valves are situated in two separate chambers which are in communication through suitable ducts, and said valves are controlled =by rockers operated by a slide provided with a push member, the said slide carrying two diametrally opposed rollers rolling on a cam solidly iixed to the driving shaft, which ensures the alternating linear movements necessary for delivery.

The portion of each rocker incorporated in the charnbers of the suction or intake and delivery valves is completely insulated from the outside by spherical sealing joints having a constant volume.

The end of the intake or suction valve is connected to the end of the sleeve of the rocker by a exible ring which ensures the opening and closing of the valve in a positive manner, whilst the delivery valve may rest on the corresponding rocker Iby its own weight; in this case, an elastic tongue whose free end continually bears on the delivery valve exerts thereon a suicient force to prevent any irregular displacement of the valve under the iniiuence of the pressure of the delivered fluid. Y

The movements of the rockers causing the opening and closing of the valve are eiected by a push member actuated lby the aforesaid slide with interposition of springs, and so that the closing of the suction and the opening of the delivery are successively effected without the possibility of communication between the two chambers.

In order to compensate for compression and expansion yforces at the springs of the rockers operating the valves and to keep the lrotational speed of the motor strictly constant despite the periodic variations in the resistant torque, the slide acting on the push member of the rockers comprises two opposed ramps of such .a conliguration that a roller, mounted on a pivoting lever on a disc driven by 3,333,543 Patented Aug. 1, 1'967 ICC the driving shaft, in following the said ramps, compresses or relaxes a coil spring connected, on the one hand, to the disc and on the other hand, to the end of the pivoting lever, so that it ybecomes possible to brake the speed ofthe motor when the latter tends to rotate more quickly, and to speed up the motor when it tends to rotate less quickly.

Other features will become apparent from the following description which refers to the accompanying drawings wherein:

FIGURE l is a longitudinal sectional view of the pump assembly taken on I-I of FIGURE 2;

FIGURE 2 is a cross section of the same assembly on II-II of FIGURE 1;

FIGURE 3 is a cross section of the same assembly on III- Ill of FIGURE 1, looking on to the opposite face;

FIGURE 4 is a View showing the regulating mechanism and FIGURE 5 is a side view of the same mechamsm;

FIGURE 6 is a partial view of the slide controlling the rockers with the regulating ramps.

Referring now to the iigures, there is mounted on a base 1 by means of a cradle 2 a casing 3 closed at one side with a vertical counter-plate 4 and supporting at the other side a casing 5 with cover 6 for accommodating a synchronous motor 7. This motor is provided with a reduction gear of any desired type capable of reducing the speed of the motor for example lfrom 1,500 revolutions per minute to 2 revolutions per minute. Fixed on the counter-plate 4 by any suitable means are a distributor unit 8 and the pump body proper 10 whose chamber is 'lined with a cylindrical liner 9 which may be made of glass, plastic material, stainless steel and, ygenerally speaking, of any sterilisable incorrodible material. The liner 9 is held in its housing -by a nut 25. The driving shaft 11 at the output side of the reduction box is supported by a bearing 14 lodged in the counter-plate 4; it drives an eccentric 12 constituted by a sleeve of variable and regulatable eccentricity as will -be indicated hereinafter, and on its external surface there rolls at one time, a roller 13 connected by a link 24 to the pump piston 15 which may be made of glass or any other material, by means of a

coupling device

16, 17; at another time a roller 13a, the xed spacing of the two rollers being such that they simultaneously rest on the sleeve 12 at the top and bottom neutral points of the piston 15. The fluid pumped in and delivered by the displacement of the piston 15 within the pump chamber passes through the ducts 18 shown in full lines and 19 shown in dot-dash lines since the latter are situated above the section plane.

The sleeve 12 forming an eccentric is mounted in a fork 20 mounted pivota-bly on a pin 22. The two

rollers

13, 13a, carried 'by the fork, successively roll on the sleeve. The fork may be optionally positioned depending on the desired travel, i.e., depending on the desired delivery to be obtained; the adjustment is obtained by two opposed screws 21 which are accessible from the exterior through a cylindrical orifice 23 in the casing 3 (FIG. 2).

In FIGURES l and 2, the eccentric sleeve 12 has been illustrated in its position centered on the axis 11 of the motor 7. In this position, the piston obviously remains motionless. The possible eccentricity `is e (FIG. 2). Considering the rotation-direction r, when the sleeve 12 is given a certain eccentricity e towards the bottom, the roller 13a, resting on the sleeve, operates for 180 to lower the piston 15 towards the bottom, and then, immediately the roller 13 contacts the sleeve 12 and produces a reverse movement of the piston.

As it may `be seen in FIGURE 2, the pin 22 of the fork 20 which carries the

rollers

13 and 13a in its median position is substantially placed on a perpendicular axis to the piston, passing through the axis of the roller 13. Whenl the eccentricity e is changed for the adjustment of the 3 lluid delivery (FIG. 2), the fork 20 rotates: the roller 13 substantially remains at the same contact point on the sleeve 12, due to the position of the pin 22, whi-le the lroller 13a displaces its contact point with the sleeve 12 in the direction of rotation r, that is the delay direction.

It is known that in the case of sma-ll fluid deliveries, the displacement of the pumped in liquid is produced with a delay in view of the displacement of the piston. This possibly results from the fact that dissolved gases are always included in the liquid and that they slowly escape, under the eiect of a decrease of pressure due to the pumping action, therefore before the liquid starts to move. This delay decreases and is subsequently nulliiied with the increase of the liquid delivery, because the escape of the gases does not have the time to be dissolved completely.

The shape of the cam 42 is set to produce a constant delay at the beginning of the suction action, that is in view of the passage of the piston at its upper neutral point for the little deliveries. The increase of the delivery by the variation of the eccentricity e results in a progressive delay of the passage of the piston at the upper neutral point, due to the corresponding rotation of the fork as it has been explained above; it results that the initial delay of the opening of the pumping through the rocker 30 is progressively reduced by the movement of the fork in case of an increase in the delivery. The determination of this reduction which obviously depends on the distance of the pin 22 of the fork to the axis of the roller 13a, is empirically determined according to the liquids used.

According to FIGURE 3, the distributor casing 8 comprises two housings for the suction and

delivery valves

38 and 47, which are mobile in the rings 48 held in place by Iplugs 34 and 36 ensuring a tight seal. The plug 36 carries the suction pipe connection 37 and the plug 34 carries the delivery pipe connection 35. The fol-lowing arrangements aim at preventing any perturbation in the smooth operation of the pump in the variations of the volumes located at the upper and lower ends. The housings of the

valves

38 and 47 open respectively into the perpendicular chambers 49 for suction and 50 for delivery. The

rockers

30 and 31 have one end movable in these chambers and are centrally supported by sealed spherical bearings 32, which enables a free angular displacement of the rockers about the said bearings without any volume variation. The end of each rocker situated within the

chambers

49 and 50 acts on the valves 3S and 47 and may be covered with a sleeve 33 of texible plastic material which is sterilisable. The end of the rocker 30 is connected to the valve 38 by a flexible ring 58 tted on to the said valve which is provided with a suitable collar. Between the end of the delivery valve 47 and the end of the rocker 31 there is interposed an elastic tongue 53 which is parallel to the rocker, which exerts on the end of the valve a slight pressure opposing pumping movements of the valve in its housing. The chambers in which the rockers are displaceable are perfectly duid-tight.

Displacement of the rockers is effected by a at slide 26 carrying two. rollers 41 which roll on a double cam 42 driven by a driving shaft 11; the slide, guided by a ixed stud 44 sliding in a notch 5I, therefore has a linear alternating movement in the sense of the arrows f1 and f2. The slide terminates at its upper end in a push member 27 accommodated in a casing 8 and iixed to a spherical sliding bearing 28 situated between the two

rockers

30, 31. Compressed springs 29'and 52 are lodged in the casing, which constantly apply the rockers against the bearing and are opposed in equilibrium as illustrated in FIG. 3. In its displacement, the slide 26 entrains the push memlber 27 and the bearing 28. When, progressively, the rocker 31 displaces itself in the direction of the opening of the delivery valve 47, -by compressing the spring 52; the force of the spring 29 of the suction valve previously compressed is exerted on the rocker 30 in the direction of closing the suction valve 38. In the other part of the movement of the slide, the spring 52 which had been compressed exerts its force on the rocker 31 which acts in the sense of closing the valve 47 and the bearing 28 acting on the rocker 30 in the sense of opening the suction valve compresses the spring 29.

It is obvious that the alternating compression and relaxation of the springs are not without intluence on the running state of the motor, which in order to ensure exact-ly the desired delivery rate, should rotate at a constant running speed. For this purpose, the apparatus compnses a regulator capable of providing a remedy for operating shocks. The mechanism involved in regulation consists in interposing between the driving shaft and the slide actuating the rockers, but subjected to the compression and relaxation of the springs of the

rockers

29 and 52, a spring which can `be compressed when the motor tends to rotate more quickly and relaxed in the opposite case. For this purpose, the slide 26 comprises at its centre an aperture 40 and opposed ramps 43. Parallel to the slide 26 there is mounted on the driving shaft (FIGS. 3 to 6) a disc 45 on which is pivotably mounted a lever 56 carrying at its end a roller 54 capable of travelling along the ramps 43. A coil spring 57 is fixed on the one hand to the disc 45 at 4S, and on the other hand to the lever 56, so that any relative movement given to the lever by the roller 54 following the ramps will tend to compress or relax the spring 57. Any movement tending to compress the spring tends to have a braking effect on the disc, that is to say to slow down the motor, and vice versa. Therefore, it is sufficient to provide a configuration for the ramps 43 to regulate the speed of the motor in an effective manner.

Thus constituted, the pump according to the invention is self-priming and its operation automatically ensures the elimination of all gaseous bubbles from the time of stating. The delivery of the uid delivered is so regular that the level of the fluid delivered in a tube shows a very regular height without any agitation, contrary toV all devices used at the present time wherein the suction and delivery periods have repercussions on the column of fluid, the level of which is not at al1 stable.

It is advantageous for bringing the pump rapidly into service to begin with a maximum delivery and to progressively reduce the delivery to the desired value; elimination of gaseousbubbles and t-he like is then eiected under the best possible conditions.

What I claim is:

1. A liquid pump having a smooth and adjustable delivery, comprising a chamber containing a cylinder, a pump piston, and circulation channels for the liquid, a synchronous motor, means for actuating the piston by a positive control through the motor, suction and delivery valves, located in the chamber, a rocker control for each of the said valves passing through the said cham-ber, a sealed joint for supporting each rocker through the charnber, and control means for the rockers through the said synchronous motor.

2. A pump according to claim 1, wherein each rocker is a bar, the means to control the rockers comprising a rod substantially perpendicular to the rockers, a spherical piece solidly fixed to the -rod for supporting the rockers, two springs, one for each rocker, compressed in opposite direction, a cam carried -by the output shaft of the said motor, guiding means for the said rod in translation according to its axis, at least one roller carried at the free end of said rod and bearing on the said cam.

3. A pump according to claim 2, wherein the control means for the rockers by the said motor 'include the said cam carried by the said output shaft of the motor, a slide solidly fixed to the said control rod of the rockers, with a I linear guiding slot, two rollers carried by the slide and lresting on both sides ofthe said cam.

4. A pump according to claim 3 comprising a compensating means for the variations of the efforts supported by the motor due to the alternative compression of the springs resting on the rockers, comprising a cam carried 'by the said slide, a disc solidly xed to the output shaft of the motor and perpendicular to the latter, a lever actuated on the said disc, a roller carried at one end of the said lever and resting on the said cam, a spring under tension between the other end of the said lever and a point on the said disc.

5. A pump according to claim 1, wherein the positive control comprises an eccentric constituted by a cylindrical sleeve carried by an output shaft of the motor, adjusting means for the eccentricity of the said eccentric, two rollers having a -xed spacing corresponding to the simultaneous contact point across a diameter of the sleeve of the eccentric, a fork supporting the said rollers, a xed pivoting shaft for the said fork, parallel to the driving shaft of the motor, and substantially located on an axis perpendicular to the piston passing through the median position of one of the rollers, a link articulated on a roller and on the pump piston.

6. A pump according to claim 1, wherein the suction and delivery valves and the part of the rockers located within the said cham-ber are completely located in the volume of the chamber containing the liquid circulation.

7. A pump according to claim 6, wherein the rockers are connected to the valves, the upper valve being connected by its own Weight, and the lower valve being connected by a connecting piece made of exible material between the ends of the rocker and the valve.

8. A metering pump having a smooth adjustable delivery ow comprising:

(a) a pump body including a cylinder and a pump piston,

(b) a synchronous motor,

(c) positive driving means connecting said motor to the said pump piston,

(d) suction and delivery valves mounted in a distributor unit,

(e) duct means to provide the circulation of a liquid from the said pump lbody to the said valves,

(f) rocker means for actuating each valve,

(g) a pusher member connected to the rocker means for actuating successively each valve through the positive driving means,

whereby a Iregular and smooth liquid delivery is obtained during the actuation of the valves.

9. A pump as recited in claim 8, wherein the rocker means comprise two bars, actuated Iby the pusher member at approximately 90 to the bars, a spherical bearing solidly mounted on the pusher member between the two bars, each bar being biassed against the said bearing by a spring, a cam member mounted on an output shaft of said motor, the said pusher member being actuated by the rotation of the cam member.

10. A pump as recited in claim 9, comprising a slide iixed to the pusher member, a linear guiding slot in said slide, two rollers mounted on said slide and resting on the cam so as to follow the contour of the cam.

1i. A pump as recited in claim 1i), comprising compensation means for the variations of the speed of the motor due to the compressions of the springs.

12. A pump as recited in claim 11, wherein the compensation means comprise a second cam connected to the slide, a disc solidly `mounted perpendicular to the output shaft of the motor, a lever pivoted on said disc, a roller mounted at one end of said lever and biassed in the direction of the said second cam whereby the said second cam is computed to damper any variation in speed of the motor.

13. A pump as recited in claim 8, wherein the positive driving means comprise an eccentric constituted by a cylindrical sleeve axially mounted on the output shaft of the motor, means for throwing the said sleeve off center, two rollers having a iixed spacing corresponding to the diameter of the sleeve and rolling on the said sleeve, a fork for supporting the said rollers, the said fork pivoting on an axle parallel to the axis of the shaft of the motor, and substantially perpendicular to the axis of the piston passing through the median position of one of the rollers, and a pivoting link between one of the rollers and the pump piston.

14. A pump as recited in claim S, wherein the suction and delivery valves and a part of the rockers are located within a liquid circulation chamber, the upper va-lve `being connected to one rocker by its own weight and the lower valve being connected to the other rocker at their extremities by a connecting piece made of flexible material.

Reierences Cited UNITED STATES PATENTS DONLEY J. STOCKING, Primary Examiner. LAURENCE V. EFNER, Examiner. W. I. KRAUSS, Assistant Examiner.

Claims

8. A METERING PUMP HAVING A SMOOTH ADJUSTABLE DELIVERY FLOW COMPRISING: (A) A PUMP BODY INCLUDING A CYLINDER AND A PUMP PISTON, (B) A SYNCHRONOUS MOTOR, (C) POSITIVE DRIVING MEANS CONNECTING SAID MOTOR TO THE SAID PUMP PISTON, (D) SUCTION AND DELIVERY VALVES MOUNTED IN A DISTRIBUTOR UNIT, (E) DUCT MEANS TO PROVIDE THE CIRCULATION OF A LIQUID FROM THE SAID PUMP BODY TO THE SAID VALVES, (F) ROCKER MEANS FOR ACTUATING EACH VALVE, (G) A PUSHER MEMBER CONNECTED TO THE ROCKER MEANS FOR ACTUATING SUCCESSIVELY EACH VALVE THROUGH THE POSITIVE DRIVING MEANS, WHEREBY A REGULAR AND SMOOTH LIQUID DELIVERY IS OBTAINED DURING THE ACTUATION OF THE VALVES.