EP4010120A1

EP4010120A1 - Apparatus for operating a piston-type dosing pipette syringe or similar device

Info

Publication number: EP4010120A1
Application number: EP20799811.3A
Authority: EP
Inventors: Tamás HADAS
Original assignee: Innogamma Kft
Current assignee: Innogamma Kft
Priority date: 2019-08-06
Filing date: 2020-08-06
Publication date: 2022-06-15
Also published as: WO2021024006A1; HU5191U

Abstract

Device for the operation of a piston-type liquid dispensing device, in particular a pipette syringe or the like, comprising a housing (10), a driving unit (30) arranged in it, a movement converter unit (40) connected to said driving unit (30), whereas the movement converter unit (40) is in releasable motion-transducing connection with a piston rod (la) of a liquid dispensing device (1) comprising a piston and the piston rod (la) through an inserted piston rod clamping mechanism (50), furthermore, a positioning unit (11c) formed on the housing (10) for positioning the liquid dispensing device (1) fitted to the housing, a clamping unit (20) associated with a receiving seat (11c) used as positioning means, suitable for the releasable fixing of the liquid dispensing device (1), where the clamping unit (20) is in operating connection with the movement converter unit (40) so that it fixes the liquid dispensing device (1) connected to the receiving seat (11c) at the receiving seat (11c) prior to gripping the piston rod (la) of the liquid dispensing device (1) in the piston rod clamping mechanism (50), and it releases the liquid dispensing device (1) following the release of the piston rod (la) of the liquid dispensing device (1) fixed at the receiving seat (11c) from the piston rod clamping mechanism (50).

Description

Apparatus for operating a piston-type dosing pipette syringe or similar device

The invention relates to a piston-type dosing pipette syringe device, in particular pipette syringe or similar device comprising a housing and a driving unit arranged in it, where the driving unit comprises a step motor, further comprising a movement converter unit connected to the driving unit, whereas the movement converter unit is in releasable motion-transducing connection with a piston rod of a liquid dispensing device comprising a piston and the piston rod via an inserted pis ton rod clamping mechanism and, furthermore, a positioning unit formed on the housing for posi tioning the liquid dispensing device fitted to the housing.

Today, various radiating isotopes and other radioactive substances are being increasingly used in the fields of industry and medicine. With such substances it is particularly important to dispense the exact amount of the radiant substance into a specific carrier due to the harmful effects of ra diation on the living organism.

US 2009/166370 discloses a hand-operable dispensing apparatus. The main feature is that the ra diating substance to be dispensed, together with the capsule to be filled and the dosing appara tus, is placed within a radiation protection cab. A person performing the dosing can manipulate the dispensing apparatus between the vial containing the radiating substance and the tray holding the capsules by means of two manipulator arms. The disadvantage of this solution is that manual dosing is slow and puts heavy physical strain on the operator. A further disadvantage is that expo sure to radiation, even with the use of protective equipment, poses a health risk.

To eliminate the above problems, automated equipments are used in more and more places to formulate radioactive substances. Such means are disclosed in CN 108542780 and CN 107744468, respectively.

In such known solutions, the dosing head is moved between the vial containing the radiating sub stance and the receiving capsule to be filled by means of driving units, and electronic transmit ters, position sensors and controls are used to achieve sufficiently accurate movement and dos ing.

Such integrated electronic control devices, however, have the disadvantage that they fail in a short time in a radiating environment, and their replacement and repair are also complicated tasks. Moreover, because of the parts exposed to radiation, enhanced health safety measures need to be observed, further increasing repair and maintenance expenses.

Another disadvantage is that the positioning means gripping and holding the pipette tips used as dispensing means can only be solved in a complicated way, which increases the probability of fail ure on the one hand, and makes the device significantly more expensive on the other. The positioning means of liquid dispensing devices positioning the pipette tip is very often a slightly conical beak-like protrusion upon which the pipette tip is pushed, and this gets stuck on it so tightly that the piston of the apparatus can be operated without the pipette tip falling off. The deficiency of this solution is that, for the automated take-up of one or several pipette tips, a slight pressure must be applied by the moving apparatus onto the pipette tip in a fixed position, which may damage the latter, or as the pressure being identical for each of several pipettes, this may cause problems due to the dimensional differences of the pipette tips due to manufacturing. It is a further disadvantage that, in case of the manual dosing of radioactive substances, putting on the pipette tips by manipulator arms is a cumbersome and time-consuming process.

Especially with manual apparatuses, solutions whereby the removal and separation of the pipette tip, fixed onto the apparatus and filled with liquid, from the apparatus can already be simplified. A mechanical structure of some sort operable mainly manually is applied for this purpose, e.g. a sleeve which, when it collides with the pipette tip, pushes the pipette tip off an element of the apparatus providing for its fixing until then. Such solution is disclosed e.g. by EP 2625530 Bl. This pushing off is concurrent in most cases with a jumping motion that must be compensated by the appropriate gripping of the pipette tip or tips.

WO 2008/107147 A1 discloses a possible solution for the positioning and fixing of the pipette tip on the apparatus where the pipette tip fitted to the apparatus is gripped and held by spring means arranged in the apparatus, and the pipette tip is removed by forcing these spring means apart. It is a deficiency that the operator must force the spring means apart to insert the tip, thus the automated affixing of the tip is not solved. Our goal with the solution according to the inven tion is to eliminate the deficiencies of the known dispenser apparatuses and to create a device that can easily pick up or put down the liquid dispensing device used for accomplishing the task concerned, e.g. the pipette used for dispensing a radioactive substance or any other means re quired for formulating, or the capsule or even the syringe to receive the radioactive substance, and includes a small number of parts preferably without electronics, and operates reliable also in a radioactive environment.

The recognition which has led to the design according to the invention was that by connecting the driving motor generally used in such devices to a movement converter unit of novel design, con sisting of merely mechanical components, via an unusual driving unit, and using one of the mov ing structural components of this movement converter unit in a special way to operate by its movement a gripping device for gripping the liquid dispensing means in a controlled way, control- ling and coordinating the various displacements can be performed with the help exclusively of mechanical connections upon which radioactive radiation, for example, has not effect and thus no failure originating from this circumstance can occur.

The task corresponding to the goal has been solved by a piston-type liquid dispensing device, in particular a device for the operation of a pipetting syringe or similar device comprising a housing and a driving unit arranged in it, where the driving unit comprises a step motor, further compris ing a movement converter unit connected to the driving unit, whereas the movement converter unit is in releasable motion-transducing connection with a piston rod of a liquid dispensing device comprising a piston and the piston rod via an inserted piston rod clamping mechanism and, fur thermore, a positioning unit formed on the housing for positioning the liquid dispensing device fitted to the housing. The device comprises a clamping unit associated with a receiving seat used as positioning means, suitable for the releasable fixing of the liquid dispensing device, where the clamping unit is in operating connection with the movement converter unit so that it fixes the liq uid dispensing device connected to the receiving seat at the receiving seat prior to gripping the piston rod of the liquid dispensing device in the piston rod clamping mechanism, and it releases the liquid dispensing device following the release of the piston rod of the liquid dispensing device fixed at the receiving seat from the piston rod clamping mechanism.

In a preferred embodiment of the device according to the invention, the movement converter unit has a threaded rod; the rotational axis of the step motor is in torque-transferring connection with the threaded rod of the movement converter unit through a driving unit; in addition to said threaded rod, the movement converter unit is supplemented with at least one another threaded rod and a slide being in torque-transferring connection with the threaded rods; the housing has a first closing member and a second closing member placed at a distance from it; the slide is slidably inserted between the first closing member of the housing and the second closing member of the housing in the direction of the longitudinal major axis of the housing; the slide has at least two female sleeves with longitudinal axes parallel to the longitudinal major axis of the housing, the at least two female sleeves are led through the slide; one threaded rod is passed through one of the female sleeves; the other threaded rod is passed through the other female sleeve; one end of each threaded rod is rotatably inserted into the first closing member of the housing, the other end is rotatably inserted into the second closing member of the housing; first driving elements be longing to the driving unit are fixed at the movement transmitting section of the threaded rods in the environment of the second closing member; a second driving element belonging to the driving unit and cooperating with the first driving elements is fastened to the shaft of the step motor of the driving unit; furthermore, the clamping unit comprises at last one axle element, a first move ment control unit, a second movement control unit, a gripping member, a supporting bracket and a tensioning member; and in the first closing member of the housing or in a holder arranged in its environment at least one opening is formed; the axle element is moveably led through the open ing; one movement control unit is fitted into the opening; the second movement control unit co operating with the first movement control unit is formed on the axle element; furthermore, the gripping member is fastened to the axle element in the vicinity of the outer end of the first closing member, at the outer side of the first closing member, whereas the supporting bracket is ar ranged on the axle element in the vicinity of the of the inner end of the axle unit extending be yond the inner side of the first closing member, and the tensioning member is inserted between the supporting bracket and the first closing member of the housing or the holder, and the piston rod clamping mechanism connectible to the piston rod of the liquid dispensing device is arranged on the outer side of the slide facing the first closing member of the housing.

According to another characteristic of the device according to the invention the piston rod clamp ing mechanism has a first clamping member and a second clamping member connected to the outer side of the slide, capable of flexible deformation and including a right angle to each other, as well as a shaped jaw arranged at the outer end more distant from the slide of the first clamping member and a shaped jaw arranged at the outer end more distant from the slide of the second clamping member, and on at least one of the jaws of the piston rod clamping mechanism a first forcing means defining a forced trajectory and on the housing or one of the closing members a second forcing means cooperating with the first forcing means and thus forcing the jaw to make a movement of a given size is arranged.

In another possible embodiment of the device, the first forcing means is formed by an incision made on the jaw or the housing or on one of the closing members, and the other forcing means is formed by a pin extending from the housing or one of the closing members or the jaw into the in cision.

In yet another embodiment of the device according to the invention, the clamping unit includes two axle elements, a first member for movement control, a second member for movement con trol, a gripping member, a supporting bracket and a tensioning member, and two openings are formed in the holder arranged in one of the closing members of the housing or its vicinity; the in dividual axle elements are moveably led through the openings; the individual members for movement control are fitted into the opening; the second members for movement control coop- erating with the first members for movement control are formed on the axle elements and, fur thermore, the gripping members are fixed to the respective axle element at the outer end in the vicinity of the first closing member of the axle elements from the outer side of the first closing member, the supporting brackets are arranged on the given axle element in the vicinity of the in ner end of the axle elements extending beyond the inner side of the first closing member, and the tensioning members are inserted between the supporting brackets and the first closing member of the housing or the holder, and the two axle elements are arranged in the housing separated by a distance, but parallel to each other.

In yet another preferred embodiment of the device, the first member for movement control in serted in the opening of the clamping unit is a female sleeve, and its second member for move ment control formed on the axle element is a strip thread formed on at least part of the axle ele ment's outer surface and cooperating with the female sleeve.

In a further preferred embodiment of the device according to the invention, the tensioning mem ber of the clamping unit is a spiral spring, and the section of the axle element between the slide and the first closing member or the holder is arranged in the space part enclosed by the spiral spring.

In another preferred embodiment of the device according to the invention a slide bar is formed at the internal end of at least one axle element of the clamping unit, forming the extension of at least one axle element and extending coaxially with the longitudinal axle of the axle element; the slide is equipped with a bypass, and the slide bar of the axle element led through the bypass of the slide is rotatably mounted in the other closing member of the housing.

In another preferred embodiment of the device according to the invention, the first driving ele ments belonging to the driving unit and the second driving element cooperating with the first driving elements are formed by gears.

In another preferred embodiment of the device according to the invention, the first clamping member of the piston rod clamping mechanism and its second clamping member are made of spring steel material.

In yet another preferred embodiment of the device, an anti-friction pad is arranged on the outer side of the slide, in the vicinity of the bypass, and the supporting bracket of the axle element is in contact with the anti-friction pad.

The device according to the invention has many advantageous properties. The most important of these is that, thanks to its movement transmitting unit having a specially designed mechanism, and the clamping unit being in a novel-type connection with it and realising essentially mechanical control, the take-up, clamping, issuing and handling of the liquid dispensing device can be imple mented with a single motor, without using any electronic means. It is sufficient to simply fit (ad just) the liquid dispensing device to the positioning member of the device, e.g. its receiving seat, and the gripping member fixes the device securely and quickly without having to exert any outer force and even before the piston rod clamping mechanism started moving the piston of the de vice. Similarly, the gripping member releases the liquid dispensing device only after the liquid in it had been emptied. Of course, the same sequence of actions takes place also if the liquid dispens ing device is moved. Thanks to this solely mechanical operation, use in the environment of sub stances emitting radioactive radiation will not damage the device either; the "control" cannot be ruined. The advantage of this is that the device can be operated much more reliably than the known versions equipped with electronic control. Moreover, its maintenance demand and the probability of failure are also smaller.

Another advantage is that, thanks to the special mechanical connections, it is suitable for the exe cution of many tasks that could not be solved or could be solved in a much complicated way with the known devices. Thus, for example, the device according to the invention is suitable for taking up and gripping an open capsule-half to be filled and after filling fitting it to the another half of the capsule.

It is also advantageous that clamping unit and the movement transmitting unit are made up of threaded spindle - female sleeve pairs, the processing of which is a routine operation that can be performed simply and with high accuracy. Thus the device itself is made up of a small number of easy-to-manufacture and easy-to-assemble parts.

A resulting advantage, in addition to reliable operation, is the simple structural design and the possibility of realising accurate dosing and, consequently, the full automation of dosing and radio active formulation.

A further advantage deriving from the possibility of full automation is that the need for live labour in the radioactive environment is minimised, which is of great importance from the point of view of occupational safety and health. The other advantage is the reduction of production time spent on the production of one capsule, and thus the low-cost increase of production capacity.

In the following, the device according to the invention is disclosed in more detail based on an ex emplary embodiment, referring to the drawings. In the drawings, Figure 1 shows a possible embodiment of the device according to the invention in side view, partly in section;

Figure 2 is the view of the device according to Figure 1 from the direction II;

Figure 3 shows a detail of a section of Figure 2 along plane Ill-Ill;

Figure 4 is a detail of a section of Figure 2 along plane IV-IV;

Figure 5 is a detail of another embodiment of the device according to the invention in section; and

Figure 6 shows a detail of the bottom end position of the device in open position of the piston rod clamping mechanism.

Figure 1 shows an embodiment of the device according to the invention which can be mounted on a 3D robot, and carries as a liquid dispensing device 1 a piston-type dosing pipette. It is possi ble to observe a first closing member 11 placed at the bottom of a housing 10 arranged in vertical position, and a second closing member 12 fixed in the upper region of the housing 10. In the em bodiment shown, on the side of the second closing member 12 opposite the first closing member 11, but still in the protection area of the housing 10, a step motor 31 of a driving unit 30 is lo cated, which provides driving for all moving parts of the entire device.

In addition to the step motor 31, the driving unit 30 possesses also a driving sub-unit 33 compris ing driving elements 33a, 33b. Driving element 33b is fixed onto a shaft 32 of the step motor 31, while driving element 33a and driving elements 33b are fixed to an end 41b of a threaded rod 41 of a movement converter unit 40 and to an end 42b of a threaded rod 42 shown in Figure 4. In this embodiment, driving elements 33a, 33b are gears, preferably helical gears.

It is also visible in Figure 1 that the movement converter unit 40 is located essentially in the closed space between the closing members 11 and 12 of the housing 10, similarly to a clamping unit 20.

In addition to the threaded rod 41 and the threaded rod 42, the movement converter unit 40 comprises a slide 43 which can move up and down in the direction of a longitudinal major axis 13 of the housing 10 by means the of threaded rod 41 and threaded rod 42. A piston rod clamping mechanism 50 for gripping and moving a piston rod la of the liquid dispensing device 1 is located on an outer side 43a of the slide 43.

Figure 2 shows the liquid dispensing device 1 of Figure 1 in bottom view. Here an outer side 11a of the first closing member 11 of the device as well as gripping members 24 used for proper fixing of the liquid dispensing device 1 to the first closing member 11 are visible in Figure 2 in closing position.

Gripping members 24 are fastened to outer ends 21a of axle elements 21 belonging to the clamp ing unit 20, and the gripping members 24 can be set from closing position to opening position and vice versa by turning the axle elements 21. A receiving seat 11c is formed on the outer side 11a of the first closing member 11, into which the liquid dispensing device 1 can be fitted before its be ing fixed by the gripping members 24.

Figure 2 also shows that the axle elements 21 of the two gripping members 24 are arranged di agonally in relation to the first closing member 11, separated from each other by a distance "t".

Figure 3 shows a longitudinal section of the device in a plane Ill-Ill indicated in Figure 2. Here the threaded rod 41 and the threaded rod 42 belonging to the movement converter unit 40, inserted between the first closing member 11 and the closing member 12 arranged at a distance "T" from each other, running parallel to the longitudinal major axis 13 of the housing 10 can be observed. The threaded rods 41, 42 are rotatably mounted into the closing members 11 and 12, so that an end 41a of the threaded rod 41 and an end 42a of the threaded rod 42 are mounted in bearings in the first closing member 11, whereas an end 41b of the threaded rod 41 and an end 42b of the threaded rod 42 are mounted in bearings in the closing member 12, so that a movement trans mitting section 41c located at the end 41b of the threaded rod 41 and a movement transmitting section 42c located at the end 42b of the threaded rod 42 run over the closing member 12 and the movement transmitting section 41c. Driving elements 33a of the driving sub-unit 33 of the driving unit 30 are arranged in this section. Said driving elements 33a are connected to the driving element 33b, which is fixed onto the shaft 32 of the step motor 31.

The slide 43 belonging to a movement converter unit 40 includes female sleeves 44 arranged in the diagonal of the slide 43 in the plane Ill-Ill indicated in Figure 2. The threaded rod 41 and the threaded rod 42 are led through said female sleeves 44. It is thus obvious that an axis 44a of the first female sleeve 44 is coaxial with a rotational axis 41d of the threaded rod 41, while an axis 44a of the second female sleeve 44 is coaxial with a rotational axis 42d of the threaded rod 42. Of course, the rotational axis 41d of the threaded rod 41 and the rotational axis 42d of the threaded rod 42 run parallel also to the longitudinal major axis 13 of the housing 10. This is the important structural design which makes it possible for the slide 43 to move - depending on the direction of the rotation - without tension along the threaded rod 41 and threaded rod 42 in the direction of the longitudinal major axis 13 when the threaded rod 41 and the threaded rod 42 rotate in a co- ordinated manner. This synchronised rotation of the threaded rod 41 and the threaded rod 42, on the other hand, is ensured by the driving elements 33a of identical number of teeth and pitch cir cle, connected to the driving element 33b.

Figure 4 shows a section of the device along plane IV-IV of Figure 2, showing the clamping unit 20 arranged in the housing 10 in more detail. Basis of the clamping unit 20 is made up by two axle elements 21 and respective members for movement control 22 cooperating with the axle ele ments 21. The members for movement control 22 are female sleeves 22a immovably fixed into the opening 15 of the first closing member 11. The axle elements 21 are equipped with a member for movement control 23, which is a strip thread 23a having a pitch adjusted to that of the female sleeve 22a of the movement control element 22. The strip thread 23a is formed into the part of an outer surface 21c of the axle element 21 close to an outer end 21a of the axle element 21.

In the given embodiment, the outer end 21a of the axle element 21, passing through one of the members of movement control 22, extends to the outer side 11a of the first closing member 11 and connects there to the gripping member 24.

Supporting brackets 25, built preferably as blocks forming a mantle with a diagonal exceeding the diagonal of the outer surface 21c of the axle element 21, are located at the inner end 21b oppo site to the outer end 21a of the axle elements 21. The supporting brackets 25 serve for providing a contact surface for the tensioning member 26 fitted in between the supporting bracket 25 and an inner side lib of the first closing member 11. The tensioning member 26 is preferably a spiral spring encompassing the axle element 21 from the inner side lib of the first closing member 11 up to the supporting bracket 25. One function of the tensioning member 26 is to keep the grip ping members 24 pre-stressed. Another function is to constitute an energy-storing unit for moving the axle element 21.

Figure 4 also shows that in this embodiment of the clamping unit 20 the axle elements 21 com prise slide bars 27 as the extension of the supporting brackets 25, passing through bypasses 43b of the slide 43 and are rotatably mounted in the closing member 12. Note, however, that slide bars 27 are not mandatory structural elements of the clamping unit 20. However, they are advan tageous for precise operation as the slide bars 27 help prevent buckling or other deformation of the axle element 21 when supporting bracket 25 and slide 43 get into contact.

It should be noted that axle element 21 and slide bar 27 can also be made as a single piece. In this case, the supporting bracket 25 can be fixed in appropriate position on the axle element 21 by e.g. wedging. Friction-reducing pads 43d are placed in the vicinity of the bypass 43b of the outer side 43a of the slide 43 to reduce the friction of the supporting brackets 25 being in contact with the outer side 43a of the slide 43 during rotation.

The axle elements 21 are embedded in the closing member 12, led through bypasses 43c of the slide 43, and fitted into the female sleeves 22a of the members of movement control 22a of the first closing member 11 so that their longitudinal axes 21d be parallel to each other and also with the longitudinal major axis 13 of the housing 10. This structural arrangement makes possible the coordinated rotation of the gripping members 24 around the longitudinal axis 21d of the axle element 21 during movement of the slide 43; this is how the liquid dispensing device 1 can be fixed in the receiving seat 11c of the first closing member 11 this way.

It should be noted that the first closing member 11 can be supplemented by a holder 14. In this case, as shown in Figure 5, the opening 15 receiving the member for movement control 22 can be fixed into the holder 14, and the holder 14 itself is fixed in the first closing member 11. This design makes it possible, in the event of failure of the member for movement control 22, or if the pitch circle of the female sleeve 22a of the member for movement control 22 needs to be changed, to replace only a pad which is easy to manufacture instead of having to replace the more compli cated first closing member 11 as a whole.

Figure 6 shows a possible embodiment of a piston rod clamping mechanism 50 of the device in open position of the piston rod clamping mechanism 50. In the given embodiment, the piston rod clamping mechanism 50 comprises a clamping member 51 and a clamping member 52 mounted on the outer side 43a of the slide 43, facing each other in an angle a of tilt, made of flat spring, and jaws 53 fastened to each of the outer end 51a of the clamping member 51 and the outer end 52a of the clamping member 52.

In the position according to Figure 6, jaws 53 are distanced from each other to be able to receive the piston rod la of the liquid dispensing device 1. For the jaws 53 to be able to reach this posi tion, forcing means 54 is formed on at least one of them, while in the given case a further forcing means 55 cooperating with the forcing means 54 is arranged on the surface of the first closing member 11 surrounding the receiving seat 11c. In present case the forcing means 54 is formed as a shaped incision 54a made on the surface of the jaw 53, whereas the other forcing means 55 is formed as a pin 55a extending from the first closing member 11 towards the jaw 53 and extending into the incision 54a. The other forcing means 55 is arranged on the first closing member 11 so as to make the forcing means 54 move upon coming into contact with it. The device according to the invention operates as follows. As an initial position the state is con sidered when the slide 43 is at its end position close to the second closing member 12. The follow ing process takes place upon switching the device on, i.e. when the goal is to "grip" a liquid dis pensing device 1.

Upon switching on the step motor 31 of the driving unit 30, the shaft 32 of the step motor 31 starts to rotate, and the other driving element 32b fixed on the shaft 32 of the driving sub-unit 33 starts to rotate the driving element 33a mounted on the movement transmitting section 41c of the threaded rod 41 and the driving element 33a mounted on the movement transmitting section 42c of the threaded rod 42 with identical angular speed. Since the end 41a of the threaded rod 41 is rotatably mounted into the first closing member 11 and its end 41b is rotatably mounted in the second closing member 12, the threaded rod 41 as well as the threaded rod 42 start to rotate around their respective own rotational axes 41d and 42d. The threads of the rotating threaded rod 41 and threaded rod 42 rotate in the female sleeves 44 formed in the slide 43 and thus force the slide 43 to move, or in case of a vertical arrangement to descend, from the second closing member 12 towards the first closing member 11.

In the given embodiment, where the axle elements 21 of the clamping unit 20 comprise slide bars 27; the slide bars 27 led through the bypasses 43b of the slide 43 do not touch the slide 43 and thus they do not hinder descent of the slide 43.

During its descent, the slide 43 reaches the supporting brackets 25 of the axle elements 21 of the clamping unit 20, and due to the forced positive mechanical engagement of the threaded rod 41 - female sleeve 44 and of the threaded rod 42 - female sleeve 44, it proceeds downwards in the di rection of the first closing member 11.

During this descent, however, the slide 43 already pushes in front of it the supporting bracket 25, which squeezes the tensioning member 26, i.e. the spiral spring, surrounding the axle element 21 and fitted between the supporting bracket 25 and the inner side lib of the first closing member 11, storing thereby energy in it.

In addition, concurrently with pushing of the supporting bracket 25, it also forces the axle element 21 to move downwards along the longitudinal axis 21d in the direction of the first closing member 11. Since the strip thread 23a forming the member of movement control 23 formed on the outer surface 21c of the axle element 21 is in connection in the opening 15 of the first closing member 11 with the female sleeve 22a formed as a member for movement control 22, during its down ward movement, the axle element 21 also rotates around its own longitudinal axis 21d according to the pitch of the strip thread 23a and the female sleeve 22a.

However, due to this turn of the axle element 21, the shaped gripping members 24 mounted on the inner end 21a of the axle element 21 turn out of their home position and free up the receiving seat 11c on the outer side 11a of the first closing member 11 designed for positioning the liquid dispensing device 1 so that the specified part of liquid dispensing device 1 can fit into the receiv ing seat 11c .

While the slide 43 is moving downward towards the first closing member 11, the jaws 53 of the piston rod clamping mechanism 50 mounted on the outer side 43a of the slide 43 also approxi mate the receiving seat 11c of the first closing member 11. During its downward movement, the forcing means 54 formed as an incision 54a in the surface of the jaw 53 reaches the forcing means 55 formed as a pin 55a in the surface of the jaw 53 protruding from the receiving seat 11c of the first closing member 11, and then the pin 55a enters the shaped incision 54a and strikes the edge of the incision 54a. While jaw 53 moves on in the receiving seat 11c, the shaped incision 54a slides further in the receiving seat 11c and the shaped incision 54a slides on along the pin 55a. Since the pin 55a stands rigidly at its place, the clamping member 51 and/or the clamping member 52 is forced to flexibly deform and the two jaws 53 placed opposite each other open, leaving space to introduce the piston rod la of the liquid dispensing device 1.

By this time the slide 43 reaches its bottom end position, and upon the signal of a micro-switch functioning as a limit switch, not indicated in the figures, the step motor 31 switches off. This bot tom "open" position is shown e.g. in Figure 4.

Then e.g. a robot, mentioned in this example, carrying the device according to the invention brings the device over the liquid dispensing device 1 and lowers it so that the liquid dispensing device 1 gets into the receiving seat 11c of the first closing member 11, and the piston rod la of the liquid dispensing device 1 gets between the jaws 53 of the piston rod clamping mechanism 50. After the positioning of liquid dispensing device 1, the step motor 31 switches on again, but its shaft 32 now starts to rotate in the direction opposite to the previous one.

As a result of rotation in the opposite sense, slide 43 of the movement converter unit 40 starts to ascend relative to the inner side lib of the first closing member 11. Due to the ascent of the slide 43, the jaws 53 of the piston rod clamping mechanism 50 also start to ascend, and due to the as cent of the incision 54a connected to the pin 55a, the stretched position of the clamping member 51 and the clamping member 52 is released. The incision 54a of the jaw 53 leaves pin 55a and the two jaws 53 get closer, gripping thereby the end of the piston rod la of the liquid dispensing de- vice 1.

In the meantime, the pressure exerted from the slide 43 on the supporting brackets 25 of the axle elements 21 also ceases when the slide 43 moves upward. Thus the tensed elastic tensioning member 26 storing energy starts to stretch upwards the already more freely moving supporting bracket 25. The supporting bracket 25 also starts to move upwards, "pulling" with it the axle ele ments 21. Due to the strip thread 23a - female sleeve 22a positive mechanical engagement, how ever, the axle elements 21 turn around their longitudinal axis 21d while ascending. Due to the ro tation of the axle elements 21, the supporting brackets 25 turn on the friction reducing pads 43d placed within the slide 43.

Under the effect of the rotation of the axle elements 21, the gripping members 24 fastened to the inner end 21a of the axle elements 21 also turn in the opposite direction relative to the previous one, and - as can be seen in Figure 2 - thanks to their shaped figures, they turn above the delimit ing edge of the receiving seat 11c on the outer side 11a of the first closing member 11, fixing thereby the liquid dispensing device 1 in the receiving seat 11c.

If the step motor 31 stops in this position, the liquid dispensing device 1 already stands in gripped position in the device, and the piston rod la of the liquid dispensing device 1 has also been con nected to the piston rod clamping mechanism 50.

Now the robot can take the apparatus equipped with the liquid dispensing device 1 to the place where it is to pick up the radioactive substance. Since this process itself is well-known and it does not fall within the scope of the present invention, these steps will be not discussed in detail here.

When the liquid dispensing device 1 enters, e.g. immerses the substance, in the given case a ra dioactive substance to be dosed, the step motor 31 switches on again and under the effect of the further rotation of the threaded rod 41 and threaded rod 42, the slide 43 moves on in the direc tion of the second closing member 12, while the tensioning member 26 fully expands and as sumes its home position. The rotation of the axle elements 21 had come to an end by this time.

On the other hand, the piston rod clamping mechanism 50 ascends further than the slide 43; thus the jaws 53 keeping the piston rod la of the liquid dispensing device 1 captive also rise further. Under the effect of the ascent of the piston rod la, the piston in the liquid dispensing device 1, e.g., in the dosing pipette, also rises and thus sucks up the radioactive substance to be dispensed in the interior of the liquid dispensing device 1. The substance extraction process lasts so long as the step motor 31 rotates the threaded rod 41 and the threaded rod 42. Following extraction of the predetermined substance quantity, the mentioned robot moves the device to the next place of operation where dosing takes place. During dosing, the step motor 31 of the driving unit 30 starts to rotate again in the same direction as in the first step. Then the slide 43 and together with it the piston rod clamping mechanism 50 start to move downwards, towards the inner side lib of the first closing member 11. Concurrently, the piston rod la fixed between the jaws 53 of the piston rod clamping mechanism 50 also moves downward and empties a part of the substance in the interior of liquid dispensing device 1 to the desired place.

During dosing, movement and operation of the threaded rod 41, the threaded rod 42, the me chanical elements of the clamping unit 20 and the parts of the piston rod clamping mechanism 50 are identical with those disclosed in the first step. When, after dispensing the last dose, the slide 43 attains its position close to the inner side lib of the first closing member 11, the robot again carries the device further to the place where the liquid dispensing device 1 can be removed.

Here the step motor 31 switches on again and lets the slide 43 further down. Pressed against the supporting bracket 25, the slide 43 triggers the rotation of the axle elements 21 and thus liberates the liquid dispensing device 1 in the receiving seat 11c of the first closing member 11 and, more over, pushes the jaws 53 of the piston rod clamping mechanism 50 into that part of the receiving seat 11c of the first closing member 11 where the pin 55a comes into contact with the incision 54a. Then jaws 53 open again, and the piston rod la of the liquid dispensing device 1 is liberated. Thus the liquid dispensing device 1 can get out of the receiving seat 11c of the first closing mem ber 11 without outer physical influence.

It should be noted that, by means of another liquid dispensing device, the device can also be used to create vacuum at the outer end of the liquid dispensing device 1 by moving the piston rod la of the liquid dispensing device 1 with which e.g. a capsule can be lifted and transmitted by means of a robot to the desired place and lowered there.

The device according to the invention is particularly applicable in all areas where hazardous sub stances, dangerous to human health must be handled, dispensed, formulated with high precision and in a reliable way. List of references

I liquid dispensing device 40 movement converter unit la piston rod 41 threaded rod

10 housing 41a end

II closing member 41b end 11a outer side 41c movement transmitting section lib inner side 41d rotational axis

11c receiving seat 42 threaded rod

12 closing member 42a end

13 major axis 42b end

14 holder 42c movement transmitting section

15 opening 42d rotational axis

20 clamping unit 43 slide

21 axle element 43a outer side 21a inner end 43b bypass 21b outer end 43d friction reducing pad 21c outer surface 44 female sleeve 21d longitudinal axis 44a axis

22 member for movement control 50 piston rod clamping mechanism 22a female sleeve 51 clamping member

23 member for movement control 51a outer end 23a strip thread 52 clamping member

24 gripping member 52a outer end

25 supporting bracket 53 jaw

26 tensioning member 54 forcing means

27 slide bar 54a incision

30 driving unit 55 forcing means

31 step motor 55a pin

32 shaft "t" distance

33 driving sub-unit "T" distance 33a driving element "a" angle of tilt 33b driving element

Claims

1. Device for the operation of a piston-type liquid dispensing device, in particular a pipette sy ringe or the like, comprising: a housing (10), a driving unit (30) arranged in it, where the driving unit (30) comprises a step motor (31), a movement converter unit (40) connected to the driving unit (30), whereas the movement converter unit (40) is in releasable motion-transducing connection with a piston rod (la) of a liquid dispensing device (1) comprising a piston and the piston rod (la) through an inserted piston rod clamping mechanism (50) and, furthermore, a positioning unit (11c) formed on the housing (10) for positioning the liquid dispensing device (1) fitted to the housing, characterised in that it further comprises a clamping unit (20) associated with a receiving seat (11c) used as positioning means, suitable for the releasable fixing of the liquid dispensing device (1), where the clamping unit (20) is in operating connection with the movement converter unit (40) so that it fixes the liquid dispensing device (1) connected to the receiving seat (11c) at the receiving seat (11c) prior to gripping the piston rod (la) of the liquid dispensing device (1) in the piston rod clamping mechanism (50), and it releases the liquid dispensing device (1) following the release of the piston rod (la) of the liquid dispensing device (1) fixed at the receiving seat (11c) from the piston rod clamping mechanism (50).

2. The device according to claim 1 characterised in that the movement converter unit (40) has a threaded rod (41); the rotational shaft (32) of the step motor (31) is in torque-transferring connection with the threaded rod (41) of the movement con verter unit (40) through a driving unit; in addition to said threaded rod (41), the movement converter unit (40) is supplemented with at least one another threaded rod (42) and a slide (43) being in torque-transferring connection with the threaded rods (41, 42); the housing (10) has a first closing member (11) and a second closing member (12) arranged at a distance (T) from it; the slide (43) is slidably inserted between the first closing member (11) of the housing (10) and the second closing member (12) of the housing (10) in the direction of the longitudinal major axis (13) of the housing (10); the slide (43) has at least two female sleeves (44) with longitudinal axes (44a) parallel to the longi tudinal major axis (13) of the housing (10); the at least two female sleeves (44) are led through the slide (43); one threaded rod (41) is passed through one of the female sleeves(44); the other threaded rod (42) is passed through the other female sleeve (44); one end (41a, 42a) of each threaded rod (41, 42) is rotatably inserted into the first closing member (11) of the housing (10), the other end (41b, 42b) is rotatably inserted into the second closing member (12) of the housing (10); first driving elements (33a) belonging to the driving subunit (33) are fixed at the movement transmitting section (41c, 42c) of the threaded rods (41, 42) in the vicinity of the second closing member (12); a second driving element (33b) be longing to the driving sub-unit (33) and cooperating with the first driving elements (33a) is fas tened to the shaft (32) of the step motor (31) of the driving unit (30); furthermore, the clamping unit (20) comprises at last one axle element (21), a first movement control unit (22), a second movement control unit (23), a gripping member (24), a supporting bracket (25) and a tensioning member(26); and in the first closing member (11) of the housing (10) or in a holder (14) arranged in its vicinity at least one opening (15) is formed; the axle element (21) is moveably led through the opening (15); one movement control unit (22) is fitted into the opening (15); the second movement control (23) unit cooperating with the first movement control unit (22) is formed on the axle element (21); furthermore, the gripping member (24) is fastened to the axle element (21) in the vicinity of the outer end (21a) of the first closing member (11), at the outer side (11a) of the first closing member (11), whereas the supporting bracket (25) is arranged on the axle element (21) in the vicinity of the of the inner end (21b) of the axle element (21) extending beyond the in ner side (lib) of the first closing member (11), and the tensioning member (26) is inserted be tween the supporting bracket (25) and the first closing member (11) of the housing (10) or the holder (14), and the piston rod clamping mechanism (50) connectible to the piston rod (la) of the liquid dispensing device (1) is arranged on the outer side (43a) of the slide (43) facing the first closing member (11) of the housing (10).

3. The device according to claim 1 or claim 2 characterised in that the piston rod clamping mechanism (50) has a first clamping member (51) and a second clamping member (52) connected to the outer side (43a) of the slide (43), capable of flexible deformation and including a right angle to each other, as well as a shaped jaw (53) arranged at the outer end (51a) more distant from the slide (43) of the first clamping member (51) and a shaped jaw (53) arranged at the outer end (52a) more distant from the slide (43) of the second clamping member (52), and on at least one of the jaws (53) of the piston rod clamping mechanism (50) a first forcing means (54) defining a forced trajectory and on the housing (10) or one of the closing members (11) a second forcing means (55) cooperating with the first forcing means (54) and thus forcing the jaw (53) to make a move ment of a given size is arranged.

4. The device according to claim 3 characterised in that the first forcing means (54) is formed by an incision (54a) made on the jaw (53) or the housing (10) or on one of the closing members (11), and the other forcing means (55) is formed by a pin (55a) extending from the housing (10) or one of the closing members (11) or the jaw (53) into the incision (54a).

5. The device according to any of claims 1-4 characterised in that the clamping unit (20) includes two axle elements (21), a first member for movement control (22), a second member for move ment control (32), a gripping member (24), a supporting bracket (25) and a tensioning member (26), and two openings (15) are formed in one of the closing members (11) of the housing (10) or in the holder (14) arranged in its vicinity; the respective axle elements (21) are moveably led through the openings (15); the first members for movement control (22) are fitted into the open ings (15); the second members for movement control (23) cooperating with the first members for movement control (22) are formed on the axle elements (21) and, furthermore, the gripping members (24) are fixed to the respective axle elements (21) at the outer end (21a) in the vicinity of the first closing member (11) of the axle elements (21) from the outer side (11a) of the first closing member (11), the supporting brackets (25) are arranged on the respective axle element (21) in the vicinity of the inner end (21b) of the axle elements (21) extending beyond the inner side (lib) of the first closing member (11), and the tensioning members (26) are inserted be tween the supporting brackets (25) and the first closing member (11) of the housing (10) or the holder (14), and the two axle elements (21) are arranged in the housing (10) separated by a dis tance (t), but parallel to each other.

6. The device according to any of claims 1-5 characterised in that the first member for movement control (22) inserted in the opening (15) of the clamping unit (20) is a female sleeve (22a), and its second member for movement control (23) formed on the axle element (21) is a strip thread (23a) formed on at least part of the axle element's (21) outer surface (21c) and cooperating with the female sleeve (22a).

7. The device according to any of claims 1-6 characterised in that the tensioning member (26) of the clamping unit (20) is a spiral spring, and the section of the axle element (21) between the slide (43) and the first closing member (11) or the holder (14) is arranged in the space part enclosed by the spiral spring.

8. The device according to any of claims 1-7 characterised in that the a slide bar (27) is formed at the inner end (21b) of at least one axle element (21) of the clamping unit (20), forming an exten sion of the at least one axle element (21) and extending coaxially with the longitudinal axle (2 Id) of the axle element (21); the slide (43) is equipped with a bypass (43b), and the slide bar (27) of the axle element (21) led through the bypass (43b) of the slide (43) is rotatably mounted in the other closing member (12) of the housing (10).

9. The device according to any of claims 1-8 characterised in that the first driving elements (33a) belonging to the driving sub-unit (33) and the second driving element (33b) cooperating with the first driving elements (33a) are formed by gears.

10. The device according to any of claims 1-9 characterised in that the first clamping member (51) of the piston rod clamping mechanism (50) and its second clamping member (52) are made of spring steel material.

11. The device according to any of claims 1-10 characterised in that an anti-friction pad (43d) is arranged on the outer side (43a) of the slide (43), in the vicinity of the bypass (43b), and the sup porting bracket (25) of the axle element (21) is in contact with the anti-friction pad (43d).