WO1998032838A1

WO1998032838A1 - Shaker

Info

Publication number: WO1998032838A1
Application number: PCT/RU1997/000136
Authority: WO
Inventors: Mikhail Nikolaevich Kazansky
Original assignee: Fraeva, Tatiyana Grigorievna
Priority date: 1997-01-23
Filing date: 1997-05-06
Publication date: 1998-07-30

Abstract

A shaker comprises a housing supporting a drive with an output shaft, a crank pivotally connected to the shaft, a platform mounted on said crank for rotation, a device for fastening flasks in slots arranged on said platform, a device for restraining a free motion of the platform and a device for an angular regulation of the platform relative to the horizontal plane. Said device for an angular regulation of the platform contains a pushing screw with a head, said pushing screw being threadedly mounted inside the hollow-made crank. Further the shaker is provided with an indicator showing a value of the platform tilt angle relative to the horizontal plane.

Description

SHAKER

Technical Field

The present invention relates to shakers generally to apparatuses for mixing, particularly emulsifications and dispersion by imparting complicated three-dimensional motion to the liquid to be mixed.

In particular the invention relates to shakers adapted to use in microbiology for procedures with microorganisms, plant and animal cells and viruses.

Background Art

Many fields of technique using high technologies deals with mixing problems, especially mixing liquids. It is of special value for microbiology in procedures related to microbiology for procedures with microorganisms, plant and animal cell cultivation and genetic tests where special and various requirements are made on the efficient mixing for providing proper conditions for cultivation without microorganism cell injury.

The rotation motion widely used in shaking other solutions in which all the points of flasks with solutions to be treated describe concentric circles has not been found useful in the growth of cells because of the centrifugation action arising from above-said motion. Because of th s the plane-parallel motion in which all the points of flasks describe equal non-concentric circles is the main constituent of mixing motion used in current shakers.

Known shakers include a movable platform for placing flasks directly on ts surface or through intermediate members (trays), flask holding means, means imparting motion to the platform together with flasks to mix the liquid therein. Means imparting motion to the platform comprises a housing, a drive (any motive power: may be electric motor or external drive) with an output shaft, a converter arranged to convert rotation motion of the output shaft to the platform motion to mix the liquid in flasks placed on said platform.

To provide above-said motion the converter usually comprises an eccentric member more commonly, a crank for imparting the motion to the centre of the platform and means for restraining the motion of the pripheral edge of the platform.

In a prior art shaker disclosed in SU Author's Certificate Publication N 309945 the platform periphery is supported on three eccentric cranks and driven by a central crank.

In another prior art shaker in US Patent Publication N 3601372 m which objects are shaken with the movable means being drivmgly connected to the external drive means through magnetic elements the provision is made of an additional eccentric member to restrict the motion of the platform periphery.

In another prior art shaker in US Patent Publication N 2520556 provision is made for a pitman restraining the motion of one of the platform edges .

In one more US Patent Publication N 2539851 provision is made for a parallelogram linkages restraining the platform motion and imparting an elliptical motion thereto.

In another prior art shaker disclosed in US Patent Publication N 3184222 the means for limiting the platform motion are formed by pins passing through the slots in the housing and m the platform.

In most of above-said disclosures there are means to change the eccentricity of rotation of the central portion of the platform.

In another prior art shaker in US Patent Publication N 4750845 the magnets are used to provide the self-adjustment of rigid connections restraining the platform motion at the eccentricity changing. In another prior art shaker m US Patent Publication N 2809020 the means for imposing restraining forces on the priphery of the platform are formed of spmgs attached to opposite sides of the axis of the platform.

In another prior art shaker in RU Patent Publication N 2031934 and n associated PCT/RU 92/00 169 Application Publication the similar means are formed of springs or a friction clutch for imposing restraining forces on one of the platform sides.

To make mixing more intensive and to prevent microorganism damage it is common practice to combine plane-parallel motion and perpendicular shaking motion. Such complex motion results in more adequate m- terpenetration of liquid layers spaced unevenly just as of the flask central axis so of its bottom. This action is accompanied by equalizing all the parameters of intermixed liquid and thus providing the optimal motion speed of liquid in flasks, increasing the intensity of mixing without microorganism damage.

One of the ways to provide three-dimensional motion s supporting the mixing tray with flasks in an inclined position relative to the platform (see Catalogue "American Scientific Products", 1991, pp.1456, 1068) . The similar method is also disclosed m US Patent Publication N 2520556.

There exist other ways to provide said complicated three-dimensional motion.

In a prior art shaker disclosed in SU Author's Certificate Publication N 125342 the complex motion of the platform in horisontal and vertical planes s advantageously produced by employment of such construction in which a device imparting a plane-parallel motion to the platform is suspended through flexible rubber shock absorbers.

In a prior art shaker in US Patent Publication N 4702610 provision is made for imparting the rotation to the central portion of the platform by means of flexible connectors attached to each of the corners of the platform to ensure a three-dimensional motion to the platform.

In another prior art shaker in US Patent Publication N 2552188 there is provided the angular regulation between the platform and the tray. This regulation is ensured by a screw from under the bottom of the platform. Said screw is used to lock a ball-and-socket joint connecting the platform and the tray. It is noted that the last motion is useful in growth of bacterial serums.

In above-mentioned US Patent Publication N 2809020 there is also disclosed the angularity adjustment which is carried out by a screw from under the bottom of the platform. Said screw locks an articulation joint between the platform and output shaft. The angularity adjustment may be accompanied by simultaneous changing the eccentricity.

In a prior art shaker in above-said RU Patent Publication N 2031934 in one of the disclosed embodiments thr horisontal angular regulation is reached due to the articulation joint takes an offset position with respect to axis of the output shaft and by a setting screw. Said screw is available from the top of the platform. In this provision is also made for eccentricity changing.

The shaker disclosed in the above-said patent publication has much in common with the given invention. The common features are as follows: a housing arranged to place a drive with a vertical output shaft, a platform for holding flasks with liquid to be treated, means for securing said flasks and providing their movement together with the platform, means for restraining the platform motion, a crank pivo- tally connected to the shaft and adapted to mount the platform for its rotation, means for regulation of angular orientation of the platform to horisontal plane. Sa d means is formed of a forcing screw thread mounted in a hollow portion of said crank. In this embodiment a combination comprising said crank pivotally connected with the output shaft and supporting the platform for rotation and the means restraining the platform motion is arranged to convert rotational motion of the output shaft to three-dimensional motion of the platform.

Here the articulation connection between the crank and output shaft is offset from the axis of the output shaft and a pushing screw in its different positions intersects said axis; the end of said screw resting against the end side of the output shaft is clamped on said end side by guides.

In the construction disclosed in this patent when changing the eccentricity the different platform angles correspond to the same displacements of the pushing screw.

So far as we are presently informed there exists a demand in constructions which are capable to perform a wide variety of motions for treated liquids.

The reason for this are pecularities of microorganism cultivation resulted from their versatility and demands for the environment primarily for hydrodynamics of medium which is the most important factor n producing the most favourable environment for a particular strain.

Each microorganism strain is unique and well developed only under strictly specified conditions. In the prior art efforts have been made to provide some of these conditions n laboratories. Satisfactory results have been obtained in determmg and a ntaing optimal temperature, acidity and similar parameters as well as in individual selecting of nutrient medium for every strain. In above-mentioned US Patent Publication N 2552188 it is noted that each particular microbiological process requires suitable hydrodynamics.

However there exists no machine of simple construction which is capable to perform optimal hydrodynamics suitable for particular bacterial and cell cultures. However it s just the hydrodynamics that is generally responsible for supplying the microorganism with oxygen and nutrient medium components and for release of carbon dioxide gas. In addition it is just the hydrodynamics which creates within the microorganism environment conditions as close to optimal as possible so that the individual microorganism has a chance for the best development. It has been found that microorganisms respond to some hydrodyna- mic characteristics m a different fashion. Some of them are tolerant of uniform turbulization but don't endure pick loadings while others are not tolerant of tangential constituents of motion and so forth.

Attempts to promote microorganism growth by simple facilitating the mass exchange through intensification of single-type hydrodynamics produce no results. There exists a necessity to create an own type of optimal hydrodynamics for each particular strains and strictly hold it.

Disclosure of the Invention

It is an object of the present invention to provide a shaker m which combinations and arrangements aloow to convert the rotation of the output shaft to three-dimensional movement of the platform and to simulate changes of the movement nature to select and to fix the optimal hydrodynamics for a particular microorganism for further simulation of these conditions in commercial and pilot microbiological process .

A further object of the invention is to provide a shaker in which there are means extremly quite in operation adapted to secure the flasks with treated liquid on the platform without essential changes in the shaker design.

Still a further object of the invention is to provide a shaker which is simple and inexpensive to manufacture.

Above said objectives of the invention are realized by a shaker which includes a housing in which a drive with an output shaft are mo- unted, a platform arranged to place flasks with liquid to be treated, a means for securing said flasks and providing their movement together with the platform, a means for restraining the platform motion, a shaker is further providing with a crank pivotally connected with the output shaft and arranged to mount the platform for rotation, said crank is made partially hollow in the portion arranged to support the platform, a shaker is further provided with a means for changing an angle cf the platform in respect to the horisontal plane, said means comprising a pushing screw thread mounted n the hollow portion of the crank. According to the invention the articulation connection between the crank and the output shaft is placed coaxially with the shaft, but the pushing screw is displaced through a given eccentricity from said axis. Said pushing screw has a head with graduations applied thereon. In contact joint with said head there is a sleeve fitted around the hollow portion of the crank which is provided with reference marks to indicate a value of turning the pushing screw relative to the hollow portion of the crank.

According to this invention the shaker provides spatial motion of the platform in three dimensions so as to permit the flasks positioned on said platform to rotate, swing from side to side and produce vertical up-down and down-up movements. With such complex motion of the flasks provided the rotation of liquid in flasks is accompanied by developing radial flows forcing the rotating liquid layers unequally-spaced of the central axis of flasks to be intermixed to thus provide the uniform mixing of liquid throughout the flasks.

Due to higher mixing efficiency obtainable through said motion there becomes possible to reduce the platform motion speed to thereby avoid turbulizat on and microorganism destroying.

From the foregoing it is seen that above-mentioned features allow to significantly expand the limits in varying such parameters as flask swinging amplitude, amount of vertical motions in one swing, flask rotation speed as well as to change displacement of a plane wherein the flasks produce swinging motion. With such potentials the shaker is capable of providing a variety of hydrodynamics for any examined microorganism strain.

Most important of all these features allow to simulate the hydrodynamics changes as in disclosed construction an angle of platform tilt to a horisontal line is agreed with all above-mentioned parameters of the motion.

Thus the shaker according to this invention allows to select and to fix the optimal hydrodynamics suitable for a particular microorganism and to improve the prior technique from the standpoint of mass repro- ducibility of results.

In the preferred embodiment of the invention a sleeve fitted on the crank is spring loaded in respect to the head and both members are movable for longitudinal (axial) movement and immovable for lateral (rotative) movement relative respectively to the pushing screw and to the crank. With this arrangement the angular regulation of the platform requires a minimum of maintenance.

In the preferred embodiment a device for securing the flasks on the platform includes a plane disk, a central forcing nut mounted for rotation relative to said disk and a tube-shaped connecting pipe assembled with the platform and having a thread for receiving the nut. The disk is provided with round slots to receive the flasks. The hollow portion of the crank together with the pushing screw mounted within said hollow oortion is located in the cavity of the central tube-shaped connecting pipe while the head and the upper part of the sleeve are projected outside. Sucn an arrangement reduces overall dimensions and weight of the shaker and makes its design simpler. The disk is preferable to be of a diameter smaller than the distance between the points mostly spaced apart on the periphery of said slots. The slots are preferable to be "C"-shaped in which the length of the chord in open part of a circle of each slot is smaller than its diameter. It makes the flask positioning procedure more simple.

According to the invention the shaker is provided with two rows: an upper and a lower row of flasks. The lower row of flask is placed on the platform and carries a main disk freely set on the flasks of this row while the flasks of the upper row are placed on said mam disk; the flasks of this row are fastened by an additional disk mounted on the flasks of the upper row, the forcing nut of the tube-shaped connecting pipe being cooperated with the central part of the additional disk. This arrangement increases the shaker capacity. The distance from the pivot pin connecting the output shaft and the crank is preferable to be 0.6-0.8 of the distance from the pivot pin to the mam disk. This provides the similar efficiency of mixing in the flasks of both rows .

Brief description of drawings For better understanding the invention particular embodiments of the present invention will now be described with reference to the ac- company g drawings in which:

Fig.l shows a diagrammatic sectional v ew of a shaker.

Fig.2 illustrates a device for changing a platform angle together with an indicator and a central part of a device for flask fastening.

Fig.3 is a top plan v ew of a disk.

Fig.4 shows an articulation connection between a vertical output shaft and a crank.

Fig.5 shows a diagrammatic partially sectional view of the shaker with two-row arrangement of flasks.

In the accompanying drawings the elements of the invented shaker are designated by the following numbers:

1 - housing;

2 - tray;

3 - drive;

4 - output shaft;

5 - ta l end of the output shaft;

6 - recess in a portion of a crank connected with the tail end;

7 - crank;

8 - pivot pin connecting the tail and the crank;

9 - bearing providing rotation of a platform relative to a hollow portion of the crank;

10 - tube-shaped connecting pipe;

11 - platform;

12 - round nut;

13 - connecting pipe shoulder;

14 - flask fastening device;

15 - flasks with liquid to be mixed;

16 - forcing nut;

17 - threaded portion of connecting pαpe;

18 - main disk;

19 - slots for flasks;

20 - brake (means providing platform motion restraining) ;

21 - device for platform angular horisontal regulation;

22 - pushing screw;

23 - cavity in crank;

24 - threaded connection between pushing screw and hollow portion of the crank;

25 - head of pushing screw;

26 - sleeve;

27 - side surface of pushing screw head; 28 - indicating marks on the pushing screw head;

29 - reference marks on sleeve;

30 - screw for fastening of tightening spring;

31 - screw for fastening of tightening spring;

32 - tightening spring;

33 - balance weight;

34 - cone of pushing screw;

35 - tray fastening screw;

36 - pin preventing the rotation of the sleeve (26) relative to the crank 7;

37 - groove in the crank 7 to receive the pm 36;

38 - axis connecting the head 25 with the pushing screw 22;

39 - groove in pushing screw;

40 - shaped washer;

41 - spring pressing the sleeve 26 against the head 25;

42 - locking ring;

43 - platform fastening gasket;

44 - connecting pipe gasket;

45 - main disk fastening gasket;

46 - rubber ring;

47 - additional disk.

Best modes of carrying out the invention There is shown in F g.l a preferred embodiment of the invention in which a shaker comprises a housing 1 mounted on a tray 2. The housing is arranged to place a drive 3 with an output shaft 4. The output shaft is formed at its and with a plane tail 5 arranged to enter a recess 6 in a crank 7. The crank 7 is mounted in the output shaft 4 through the tail 5 so that the axial lines A-A and B-B of the crank 7 are spaced apart through "e" eccentricity when the crank is in its vertical position. The output shaft 4 and the crank 7 are connected by a pivot pm 8, providing a plane articulation connection therebetween. The crank 7 through bearings 9 mounted in the tube-shaped connecting pipe 10 carries a platform 11. The platform 11 is fastened to the connecting pipe 10 through a round nut 12 pressing the platform 11 against a shoulder 13 of the connecting pipe 10. The device 14 for fastening the flasks 15 placed on the platform 11 contains a forcing nut 16 threaded on the upper portion 17 of the connecting pipe 10 and a main disk 18 made of resilient material. The central part of said disk 18 is mounted n a nut 16 for rotation relative to sa d nut 16 and has round slots 19 to receive the middle portions of the flasks 15. The upper end of the nut 16 is enlarged to facilitate the screwing action.

On the upper part of the housing 1 there is a device 20 restraining the free rotation of the platform 11 and comprising three cubes made of porolon which are attached on the surface of the housing 1 so as to be in a contact with the inner surface of the platform 11.

The shaker is further provided with a device 21 for changing an angle of the platform 11 relative to a horisontal plane.

Said device 21 includes a pushing screw 22 mounted m a cavity 23 of the crank 7 through threaded connection 24 and a head 25 placed in the upper part of the pushing screw 22. A sleeve 26 is fitted around the upper end of the crank 7.

The head 25 together with the periphery of the sleeve 26 forms an indicator 27 for displaycmg a value of angle of the platform relative to a horisontal plane.

The indicator 27 includes indicating marks in form of vertical notches 28 with numerals applied on the cylindrical surface of the head 25 and a reference point 29 applieα on the upper shoulder which forms a boundary line between the cylindrical surface of the sleeve and ts upper lateral surface. A screw 30 is passed into the lower portion of the crank 7 while a screw 31 into the output shaft 4. Between these screws there is provided a spring 32 arranged to tighten said screws and to provide kinematic engagement of the device 21. The side of the output shaft opposite from the spring 32 carries a balance weight 33 arranged to compensate the displacement of the platform gravity center caused by the eccentricity. The lower portion of the pushing screw is shaped as a cone 34, and the housing 1 is attached to the tray through screws 35.

The sleeve 26 (see Fig.2) is mounted movable for axial, longitudinal motion and immobable for lateral (rotation) motion. This is performed by a pm 36 fitted m the sleeve 26 and arranged to enter a longitudinal groove made in the body of the crank 7. The head 25 s mounted on the pushing screw 22 movable for axial (longitudinal) motion and immovable for lateral (rotation) motion. This is provided by an axis 38, fitted in the head 25 an by a groove 39 made in the upper part of the pushing screw 22. A shaped nut 40 is put on the crank 7 to rest against the bearing 9. Between a washer 40 and the sleeve 26 there is a spring 41 arranged to tighten sleeve 26 and the head 25 therebetween and to thus provide close kinematic contact between end faces of the sleeve 26 and the head 25. With such arrangement it s more comfortable for the operator to read the indications on the indicator 27.

The bearings 9 are mounted in the tube shaped connecting pipe 10 by means of a locking ring 42 and there is a gasket 43 between the platform 11 and a round nut 12. On the upper end face of the connecting pipe 10 there is provided q gasket 44 of sponge rubber, and the disk 18 is secured in the nut 16 through a gasket 45 and rubber ring 46.

The crank 7 and pushing screw 22 are mounted m the cavity of the central tube-shaped connecting pipe 10, while the head 25 and the upper end of the sleeve 26 are located outside of the said connecting pipe 10.

The main disk 18 (see Fig.3) is of lesser diameter than the distance "D ". "D is the distance between the points which are the most spaced apart on the circumference of the "C"-shaped slots 19 adapted to receive the flasks 15. The d sk is made so less much than distance "D " that the length of the chord "d " of the open portion of the circle is found to be less than the diameter "d" of the circle 19.

The tail 5 (see Fig.4) of the output shaft 4 enters the recess 6 of the crank 7 so far as to provide a clearance in the upper part of said recess sufficient for a turn through 5 of the crank 7 relative to shaft 4.

The flasks 15 may be placed in one storey as shown in Fig.l but two-storey arrangement s available as shown in Fig.5. In the last case the flasks form a lower and an upper storey. The lower row of flasks 15 s located on the platform 11 and secured by the ma disk 18 freely put on the lower row of flasks 15. The upper row of flasks 15 is located on the mam d sk 18 which freely put on the lower row of the flasks 15. As the circle of the upper storey surface is of less diameter the number of the flasks located thereon is less. The flasks 15 of the upper row may be placed in stagerred order relative to the flasks 15 of the lower row. In this case the number of flasks of the upper row is half as many flasks of the lower row, but the density is the most in this case.

When two-storey arrangement is used the shaker s equ ped w th an additional disk 47, which is put on the flasks 15 through its slots. The additional disk is similar in design to mam disk 18. The additional disk 47 is mounted for rotation in the forcing nut 16.

The distance "a" from the axis 8 of the articulation connection to the platform and the distance "b" from the axis 8 to the mam d sk 18 are chosen so as to provide the relationship: a = ( 0 . 6- 0 . 8 ) *b .

To start the operation of the shaker it is necessary to unscrew the forcing nut 16 not completely from the thread portion 17 of the tube-shaped connecting pipe 10 and in so doing to raise a little the disk 18 associated with said nut 16 so that to insert the flasks 15 into the slots 19 by the movement of the operator's hand m horisontal plane. Then the flasks are tightly clamped on the platform 11 by the action of the forcing nut 16.

After this operation the desired angular tilt of the platform 11 relative to the horisontal plane is adjusted. By pressing to the top of the head 25 of the pushing screw 22 and turning said head so long as the notch with numeral on the head 25 indicating the value of the desired angular tilt coincides with the mark applied on the upper shoulder which fixes the limit between the cylindrical part of the sleeve 26 and ts upper side face. In so doing the platform assumes the desired angular position as the notches on the head 25 may be graduated in degrees of the angular tilt of the platform relative to horisontal plane .

The next step is to actuate the drive 3 and to set rpm of the output shaft 4 to a value determined to be optimum for a given procedure. The rotation of the shaft 4 is imparted to the platform 11 through the crank 7 pivotally mounted on the vertical shaft 4 through "e" eccentricity. In so doing the rotation of the vertical shaft 4 is kinemati- cally converted to the complex three-dimensional motion of the platform 11. This kinematic conversion is accomplished not only by means of the crank 7, the pivot pm 8, "e" eccentricity but bearings 9 and the device 20 for restraining the rotation of the platform. The complex spatial motion of the platform in three dimensions includes the rotation of the flasks 15, their swinging from side to side and vertical up-down and down-up movements. Obviously the plane m which swinging of motion of the flasks occurrs will be rotated simultaneously with the rotation of the flasks 15.

Such complex three-dimensional motion results m developing with the rotating liquid flows radial ones forcing the rotating liquid layers irrespective of their desposition relative to the flask central axis to be intermixed to thus provide the uniform mixing of the liquid throughout the flasks 15. The motion of such nature makes it possible to obtain more uniform and more efficient mixing.

Due to higher mixing efficiency obtainable through said motion there becomes possible to reαuce the rotation speed of the platform 11 to thereby avoid turbulization of the liquid and microorganism destroying. The construction of the shaker significantly expands the limits within which the angular regulation is possible. The change of the platform angle to the horisontal plane is accompanied by the change of the eccentricity. The possibility to change many of the parameters allows to provide a variety of hydrodynamics and to determine and select the most favourable and suitable hydrodynamic environment for any strain under examination.

In Fig.5 is shown the second embodiment of the invention in which the flasks 15 are arranged in two storeys. In this case the flasks 15 of the lower row are circumferentially arranged directly on the platform 11 and clamped on it by means of the mam disk 18 freely put on the flasks 15 of the lower row. The upper row of the flasks 15 is arranged on the disk 18 and clamped on it by means of the additional disk 47 which is located on the flasks of the upper row and the central part of which is subjected to the forcing nut 16 threaded on the tube-shaped connecting p pe 10. The forcing action of the nut 16 is through the additional disk 47 transmitted to the flasks 15 of the upper row which are fastened on the mam d sk 18. But since the main disk 18 is freely put on the flasks 15 of the lower row the similar forcing action is transmitted to the flasks 15 of the lower row and fasten them on the platform 11. We may say that the forcing action of the nut 16 is used twice without reduction: for flasks 15 of the upper row and and flasks 15 of the lower row.

As compared with known shakers the invented shaker is relativly mexpens g, simpler, light and very economical.

Industrial applicability

The shaker can be used for research purposes in microbiology, biotechnology, pharmaceutical and food industries as well as in chemistry and medicine procedures. The shaker is well adapted for cultivation of microorganisms, dissolving various substances, mixing liquid preparations as well as for producing suspensions, solutions and medical preparations especially in small quantities.

As compared to known apparatuses the invented apparatus promotes quality of studies on microorganism cultivation and provides greater accuracy of researches. Because of this the invented apparatus would be appropriate m research laboratories firstly m those of them which develop new preparations and new technologies. Since the shaker provides high mass transfer coefficient with "gentle" agitation t is of 13/1 special value for mixing of fragile materials especially tissue cell cultures, microorganisms, blood cells and like.

The invention can also be used for dissolving solid substances in liquids .

Claims

14CLAIMWhat we claim is:

1. A shaker containing a housing (1) accomodat g a drive (3) with an output shaft (4), a platform (11) for flasks (15) with liquid to be treated, means (18) and (47) for clamping the flasks (15) and providing the motion of sa d flasks (15) together with the platform (11); a means (20) for restraining the motion of the platform (11); a crank

(7) characterized n that an articulation connection (8) between the crank (7) pivotally connected to the output shaft (4) and arranged to mount the platform (11) for the rotation; said crank being hollow-made in the portion which supports the platform (11); and a device for an angular regulation of the platform (11) relative to the horisontal plane including a pushing screw (22) thread mounted m the hollow portion of the crank (7) and the output shaft (4) is located on the axis of said shaft and the pushing screw is located through "e" eccentricity from said axis; said pushing screw being provided with a head (25) with graduations (28) applied thereon closely adjacent to a sleeve (26) fitted around the hollow portion of the crank and provided with reference marks (29) to indicate a value of turning of the pushing screw relative to the hollow portion of the crank.

2. A shaker as defined in claim 1 characterized m that a sleeve (26) is spring-loaded relative to a head (25) , said head (25) and said sleeve (26) being made movable for a longitudinal (axial) motion and immovable for lateral (rotational) motion relatively the pushing screw (22) and crank (7) respectively.

3. A shaker as defined in claims 1 and 2 characterized m that the axial likes (C-C) of slots of a device (14) for fastening the flasks (15) on the platform (11) are arranged circumferentially with the center being on the axial line (A-A) of the platform (11) .

4. A shaker as defined claim 3 characterized in that a device (14) for fastening flasks (15) on the platform (11) contains a plane-shaped disk (18), a central forcing nut (16) mounted for turning relative to the disk (18) and a central tube-shaped connecting pipe (10) which is interlocked with said platform (11) and provided with a thread (17) to receive a nut (16) and further said disk (18) is provided with round-shaped slots (19) to receive the flasks (15).

5. A shaker as defined .n claim 4 characterized in that a device (14) for fastening flasks (15) is made of lesser diameter "D" than the distance D between the points of said "C"-shaped slots (19) mostly 1 5 circumferentially spaced apart; the length of the chord d of the open portion of the circle of every slot s less than the diameter (d ) of said circle.

6. A shaker as defined in claims 3, 4 or 5 characterized m that the flasks (15) are arranged in two rows: lower and upper row; the lower row located on the platform (11) and carries a mam disk '18), a device (14) for fastening flasks (15) is provided with an additional disk (47) mounted on the flasks (15) of the upper row, the forcing nut

(16) of the tube-shaped connecting pipe (10) being interacted with the central part of the additional disk (47).

7. A shaker as defined in claims 1, 3, 6 characterized in that the distance "a" between the axial line of the pivot pin (8) and the platform (11) is 0.6-0.8 of the distance "b" between said pivot pm (8) and the main disk (18) .