Patent Application
20090090433
The present invention relates to an apparatus and a method for dispensing material, especially small amounts of solid material in powder or granular form.
In various industries, such as the chemical and the pharmaceutical industry handling of non-liquid materials in solid or powdery form is used for preparing mixtures, drugs, tests, in-process products or final products. Several dispensers for handling powder materials are known from prior art and it is inherent to those devices that in general the are not suitable to precisely dispense different amounts of material, especially when the amount of material to be dispensed is small (e.g. in the range of milligrams). Most important, these devices are not suitable to dispense powder materials if the starting amount is very limited, such as e.g. 30 mg or less. However, in the chemical and the pharmaceutical industry, for research, development and production, it is important to be able to precisely dose small and very small amounts of powders and solids, with different flow characteristics and independent of the starting amount.
U.S. Pat. No. 5,145,009 is directed to an apparatus for metering dry and pulverulent pourable material such as dye powder in a laboratory dyeing line for textiles. The apparatus is having a discharge container which has a closable outlet in its lower region. Scales for metering the amount of material that is to be conveyed from the outlet of the container are arranged on the underside of the container. The container is having a valve body that tapers towards the top and can be displaced vertically downwards. The valve body is arranged rotatable in closed and open position having the capability for conveying the material in the direction towards the outlet opening therefore performing a dual function. One disadvantage consists in that the device is not suitable for small amounts of material.
WO02 29371 is directed to a dosing unit for releasing a powder substance and a scale for determining the amount of substance released. The dosing unit comprises a storage container that contains the substance to be released and is mounted on a scale in such a way that the scale measures the weight of the dosing unit. As the scale measures the weight of the dosing unit including the storage container and the substance, the amount of the substance released can be determined by subtraction.
WO03 098170 discloses a device for dosing powder substances. The device comprises a substance-receiving device which is provided with a plurality of compartments suitable to receive a substance that is to be dosed and which can be emptied individually. The device also comprises an evacuation device for emptying the compartments, a scale determining the quantity of dosed substance and means for controlling the evacuation of the compartments according to the quantity of the dosed substance.
WO2005 002654 is directed to a device for dispensing individual doses of powder from pockets of a disc-shaped carrier. The doses are dispensed by rupturing a foil by pressure on an opposite side surface. The device provides individual flow paths for each pocket. Split airstreams are allowing improved entrainment of powder and a cam mechanism is provided for outwardly rupturing the pockets. Further an indexing mechanism is linked to the cam mechanism and a dose counter.
US2005 0040185 describes an apparatus for dispensing small quantities of particles. The apparatus comprises a hopper provided with a sieve at a bottom portion thereof. The hoper defining a powder-containing zone above the sieve which in use contains powder to be dispensed therefrom trough the sieve. The hopper is hold by a support so that the hopper can in use be held above a container into which the dispensed powder is to be received. At least one actuator is provided for delivering impact energy to the hopper for causing powder to be dispensed through the sieve when the hopper receives the impact energy.
WO03 026965 is from the same applicant as US2005/0040185 and also describes an apparatus for dispensing small quantities of particles. The apparatus comprises a hopper provided with a sieve at a bottom portion thereof. The hoper defining a powder-containing zone above the sieve which in use contains powder to be dispensed therefrom trough the sieve. The hopper is hold by a support so that the hopper can in use be held above a container into which the dispensed powder is to be received. At least one actuator is provided for delivering impact energy to the hopper for causing powder to be dispensed through the sieve when the hopper receives the impact energy. The actuator is arranged to deliver impact energy to the hopper from different directions and/or at different locations on the hopper.
WO2005 014397 describes a method and an apparatus for filling a container with powder in that an outlet of a hopper containing powder is positioned above an open end of the container. The hopper is mechanically agitated so as to cause powder to be transferred from the hopper to the container. By mechanically agitating the container it is ensured that the container is filled with powder at a predetermined density.
U.S. Pat. No. 6,805,175 describes an apparatus for aspirating and dispensing powder. The apparatus comprises hopper having a powder transfer port and a suction port for connection to a source of suction to establish an upward flow of air through the transfer port. A gas flow control system varies the upward flow through the transfer at different velocities, whereby the velocities include an aspirating velocity for aspirating powder into the hopper through the transfer port to form a fluidized bed of powder in the hopper, and a dispensing velocity less than the aspirating velocity but sufficient to maintain fluidization of the bed while allowing powder from the bed to gravitate through the transfer port for dispensing into one or more destination receptacles. A method of aspirating and dispensing powder is also disclosed.
WO02 11800 discloses a powder deliver device for the deliver of a physiologically active agent in powdered form into a patient's nasal cavity. The device comprises a bulk reservoir for containing multiple doses of powder, a powder deliver passage for the forced flow of gas with a dose of said powder entrained therein to a patient. A powder metering unit for metering out a dose of powder from said bulk reservoir is provided to align a metered dose with said gas flow passage.
WO03 066437 is directed to a method and an apparatus for introducing powder into a pocket using a dosator. The dosator is having an elongate cavity with an open end and a plunger opposite the open end moveable along the cavity so as to define a space of variable volume. The plunger defines a volume which is greater than that of the pocket. By inserting the open end of the dosator into a source of powder the volume is filled with powder. By positioning the open end over the pocket and driving the plunger the powder is expelled from the open end into the pocket and compressed to a predetermined bulk density.
US2001 0027823 discloses a dispensing apparatus for granular or powder bulk materials. The apparatus includes a balance to weigh doses of material being dispensed, a reservoir container and a cover to close a downward-facing opening of the reservoir container. A conveying and delivering device the cover which has a vertically movable, rotary conveyor body designed so that it can substantial close off the dispensing outlet for the bulk material. The conveyor body has a ring-shaped bottom and a ring-shaped conveyor channel which is recessed in the cover. The outlet is arranged in the ring-shaped channel and is designed to deliver a directed and locally concentrated stream of bulk material.
WO02 090896 is directed to a powder measure-dispensing cap. The dispensing cap comprises a body with a feed opening. The feed opening is supplied by at least one endless screw.
GB1488719 describes a dispenser for dispensing liquids or powder materials out of an aerosol container in which the liquids or powder materials are stored together with a propellant.
CA2160046 discloses a disposable dispensing device for dispensing solid materials in powder or granular form such as a spoon full of sugar into a cup of coffee. The dispensing device allows to dispense measured quantities which avoids having to use a teaspoon or other measuring device. The device comprises a longitudinal passage and a sliding member with a substantially rectangular cross-section. The sliding member is movable from a first position to a second position such that a dispenser aperture may be opened or closed.
CA2250574 discloses a dispenser for substances in powder or granular form. The dispenser enables a multiplicity of doses of a substance in powder or granular form contained in a reservoir to be dispensed in succession. To form a dose a shaft must be rotated relative to a part of the dispenser, whereby the shaft has to be arranged substantially vertical while the dose is being formed. It is not foreseen to dispense individual amounts of materials.
U.S. Pat. No. 5,573,340 describes a device for dispensing a liquid or powder product. This device includes a container and a stopper for sealing the container whereas a pouch made of an elastic substance with a slit is placed inside the neck of the container. The slit is open when a stopper seals the container. The slit closes when the stopper is removed from the container.
U.S. Pat. No. 3,662,930 is directed to a dispensing package for adding a medicine to a parental solution container which is characterized by a plug disposed between a medicament reservoir and a discharge conduit. The plug has a lab rinth through which solid medicament must pass on discharge. The function of the lab rinth is to prevent the additive powder from being spilled or misdistributed out of the package.
From the prior art devices are known wherein predetermined amounts of material are encapsulated in appropriate standardized containers or capsules of different sizes made out of an inert material such as glass. With these devices the minimum amount possible to be dispensed is given by the smallest standardized container available and a fine graduation is therefore difficult to achieve. A further disadvantage is the logistic effort necessary to produce, handle and store the different containers. Still a further disadvantage consists in that the remains of the containers have to be disposed or separated form the mixtures. Pre-packed containers comprising material to be dispensed may be mistaken. Therefore it must be ensured that the risk of mistaking is minimised or completely avoided.
The dispensers known from prior art are not suitable for automatic dispensing of small starting amounts in the range of that needs to be dispensed into typically used vessels and receptacles, such as plates, vials, bottles, capsules, etc., in very low quantities, like 1 mg or less. One reason for this problem consists in that the known devices are to large or have to man parts involved such that, due to the large surface of the parts involved, small quantities of powder may not be handled. Also, the waste of the powder, caused by the known devices, is considerable. Another draw back is that the devices known from prior art in general consist of a large number of parts which are difficult to manufacture, assemble, maintain and clean. A further draw back is that the devices known from prior art have to be adjusted according to the physical characteristics of the material to be dispensed or cannot be used for dispensing of cohesive powders. In addition, the known devices do loose powder during operation because the are not sufficiently sealed. Uncontrolled loss of powder may cause serious problems and contamination.
It is one object of the invention to provide a device which is suitable to precisely dispense small and very small amounts of at least one material in powder or granular form, especially when the starting amount is limited. It is a further object of the invention to provide a device that prevents negative contamination, spilling or loss of material. It is a further object of the invention to provide a device which allows recovering remaining powder without negative loss. It is a further object of the invention to provide a device for automatically dispensing at least one material in powder or granular form. It is still a further object to provide a device which is suitable to reduce the risk of mistaking.
The invention comprises a dispensing device which has, compared to the devices known from prior art, a simple setup suitable to be made of metal or injection moulded plastic, depending on the field of application. The device is made that it is easy to be filed and to be emptied without the need of extensive cleaning. Therefore it is relevant that only a limited amount of parts are in direct contact with the material to be dispensed whereby these parts are easy to clean and to maintain. Compared to the prior art, one advantage of the invention consists in that the device offers the possibility for miniaturisation which is one condition for handling small amounts of material. The device is further suitable to be used with materials in powder and/or granular form having different physical characteristics such as e.g. particle size, shape and form, density, humidity. The device further provides a high repeating accuracy such that it is e.g. possible to dispense thirty portions of 1 mg or sixty portions of 0.5 mg or a fraction of it, with a high accuracy by a single dispenser. Therefore the dispenser according to the present invention is especially suitable to be used in laboratories e.g. of the pharmaceutical and biotechnological industry and particularly for small-scale scientific research. The device avoids an risk of cross-contamination since the openings can be sufficiently sealed if necessary.
To provide a high accuracy the device preferably comprises or is interconnectable to at least one scaling means to directly or indirectly measure the amount of material dispensed. For direct measuring the scaling device is interconnected to the dispensing device itself, measuring the amount of material leaving the dispensing device. Alternatively or in addition the scaling device, for indirect measuring, is interconnected to the container determined to receive the dispensed material.
The dispensing device in general comprises at least one compartment to receive a material to be distributed, a gate valve, preferable a gate valve with variable opening, an agitator, and a conveyor. The gate valve, the agitator and the conveyor are driven by at least one drive mechanism which forms part of the dispensing device or to which the dispensing device may be interconnected by interfaces. In a preferred embodiment the agitator and the conveyor are incorporated in a single device. Depending on the field of application the dispensing device further comprises a storing means to hold information temporarily or permanent e.g. about the material, amount and condition of the material contained in the dispensing device. If appropriate the dispensing device may further comprise at least one sensor to retrieve information about the condition, such as humidity, temperature or electric conductivity, of the material contained in the dispenser.
A control unit which may form part of the dispensing device or to which the dispensing device may be interconnected controls the position and opening of the gate valve, the agitator and/or the conveyor. The control unit is, if present, further interconnected to the at least one scaling means to control or double check the amount dispensed from the dispensing device. The control unit may further comprise means to read out and store information from the storing means.
In a preferred embodiment the dispensing device is designed as an exchangeable unit having a first standardized interface suitable to be interconnected with an appropriate second standardized interface of a controller. The controller is thereby suitable to receive different dispensing devices, e.g. of different size or containing different materials. When not interconnected to the controller the different dispensing devices are preferably stored in a storing unit tightly sealed. Exchanging of the dispensing devices takes preferably place by an exchanging device which is suitable to exchange the dispensing devices automatically.
Due to the large flexibility and the setup it is possible to provide an adapter means b which the dispensing device according to the present invention may be interconnected to existing control devices as known from the prior art. The adapter means is foreseen to transfer control variables and if appropriate feedback information between the dispensing device and the control device for adjusting the opening of the gate valve.
For handling small amounts of solid material, e.g. in powder or granular form, it must be guaranteed that no needless waste and spilling of material takes place. One source of misspending with the devices known from the prior art often takes place in the area of the dispensing opening. The dispensing device according to the present invention therefore comprises a gate valve which solves this problem. In a general setup the dispensing device according to the present invention comprises a compartment for receiving a powder material to be dispensed, whereby the compartment comprises a tapered lower end with a gate valve dispensing opening. The dispensing opening is opened and closed by a blend acting as part of a gate valve which is arranged such that it provides only minimum contact with the material stored in the compartment in that the rim of the opening acts as a wiper for the material in contact with the blend guaranteeing that the material in the compartment is not wasted. Therefore the blend is pressed firmly, e.g. by spring load, against a rim of the dispensing opening or an alternative edge such that no negative amount of material may enter between the rim of the opening and the blend. Good results have been achieved by an in one direction elastic blend closing the opening from a side. The blend is guided in appropriate guiding means guaranteeing that the blend is sufficient firm pressed against the opening at least at one side. In a preferred embodiment the blend consists in a relatively thin band of elastic material guided in at least one longitudinal slot extending radially from the opening. The band of material is thereby formed and arranged such that at least in closed position it tightly closes the opening. The dispensing device may further comprise an agitator means to agitate the material stored in the compartment. If appropriate the gate valve and the agitator means comprise standardized interface means guaranteeing the exchangeability of the dispensing device. The compartment of the dispensing device may be designed such that it is hermetically closable. Especially the filling and the dispensing opening ma be sealingly closed in an appropriate way to allow storing of the material within the dispensing device.
In a preferred embodiment the dispensing device comprises a compartment to receive material to be dispensed having an in general cylindrical first section which turns into an in general conical second section. At the apex of the second section the compartment comprises an opening (gate valve) which is arranged at an angle to the longitudinal axis of the first and the second section such that an oval shape of the opening results. The opening is sealed by a blend by which the opening can be released infinitely variable from full closed to full open. The position of the blend is adjusted by a first internal or external drive mechanism which is interconnected to the control unit. In the compartment, depending on the field of application, at least one agitator is arranged rotatable and/or movable in the direction of a centre axis activated by a second internal or external drive mechanism. The agitator is preferably suitable to interact along the full length of the compartment with the material stored in the compartment. Good results have been achieved by a long thin wire-like structure extending along the inside contour of the compartment. If appropriate the conveyer can have another design depending on the material to be dispensed, such as helix like shapes and/or grating like shapes and/or scraper like shapes. The conveyer/agitator can be designed as exchangeable parts.
The agitator on one hand is suitable to mix the material stored in the compartment and on the other hand may help as a conveyor means conveying the material to be dispensed through the opening at the apex of the second section of the compartment. Depending on the material to be dispensed at least one further agitator may be arranged within the compartment moving similar or counter clockwise to the first conveyor. The agitator thereby is suitable to take influence on the morphology, the distribution of grain of the material to be dispensed. The position of the agitator and the blend may be read out by sensor means and the information is provided to the control unit which is interconnected to the first and the second drive mechanism. It is obvious that the shape of the compartment may be different as long as it does not have an negative impact onto the functionality of the device.
To dispense material out of a dispensing device according to the present invention in general the following steps are necessary:
One advantage of the dispensing device is in that only a minimum amount of pieces, having a shape easy to be manufactured and maintained, are in direct contact with the material to be distributed. The device is designed such that it can be made in mass production as a returnable or a disposable unit, in other words in form of a returnable or disposable cartridge. By the herein disclosed invention it e.g. becomes possible to provide to customers a prepacked set of dispensing devices (cartridges) containing a certain amount of repeatable used materials in powder form. The dispensing devices may then be stored in an appropriate storing device wherefrom the may be automatically retrieved by an appropriate handling device during production. To dispense material the handling device interconnects the dispensing device temporarily to a controller which controls the opening of the gate valve and the movement of the agitator and/or conveyor means. A sensor means interconnected to the controller measures the amount of material passing through the gate valve. Errors of mistaking are reduced in that each dispensing device may be marked by an appropriate tag, e.g. a radio frequency identification tag (RFID and/or an optically readable tag such as a bar code, which is read out by the controller before material is dispensed. Furthermore the tag may be appropriate to hold and save information from the controller about the amount of material dispensed from the dispensing device, the age of the material stored in the dispensing device. In the storing device a further reading device may be foreseen appropriate to read out information from the tags of the dispensing devices. Thereby it becomes possible to gain information about the amount and the condition of the material available on stock.
An embodiment of a dispensing device according to the present invention is designed to be inserted in a pipette for dispensing of solid material, whereby the pipette acts primarily as a control unit for the pipette. The pipette in general comprises a cartridge holding device suitable to receive the dispensing device as described above, a first and a second driving means by which the opening of the gate valve opening and the agitator and/or conveyer of the inserted dispensing device can be operated. In a further embodiment the pipette comprises an electronic circuit which controls and triggers the valve gate opening and/or the conveying speed of the conveyer. If appropriate the pipette may comprise an interface by which it is connectable e.g. to an output signal of a scaling means such that the amount of material to be dispensed through the valve gage opening can be adjusted in relation to the signal of the scaling means. If appropriate the pipette can be designed to receive other cartridges with a different valve gate opening and/or conveyers stem. Depending on the field of application a first driving mechanism may be incorporated as mechanical driving mechanism, e.g. comprising a lifting rod which is lifted by a ramp interconnected to a control button such that when the control button is pressed the ramp interacts with the lifting rod such that the lifting rod is lifted. A second drive mechanism is incorporated in form of an electric driving means interacting e.g. with an agitator and/or a conveyer. In a further embodiment the first and the second driving means are incorporated as electric driving means controlled manually and/or by an electronic circuit.
An embodiment of the invention comprises a dispensing device for storing and dispensing at least one material in solid form with a compartment for storing a material, a gate valve with a variable gate valve opening for dispensing the material and at least one standardised interface whereby the dispensing device may be exchangeably interconnected to at least one control unit having a corresponding interface to control the opening of the gate valve by a signal of at least one scaling means to control the amount of material dispensed. The compartment may have a tapered lower section whereby the gate valve opening is arranged at an apex of the tapered lower section. The gate valve opening may be closed by a blend which is supported by a rim of the gate valve opening. The blend may be guided in a notch extending radially with respect to the valve gate opening. The blend may consists in a band of elastic material. A scaling means may be integrated in the dispensing device. The scaling means may be interconnected to a supporting means supporting the dispensing device. The scaling means may be interconnected to a vessel suitable to receive material dispensed from the dispensing device. The dispensing device may further comprise an agitator means to agitate the material stored in the compartment. The agitator means may comprise a standardised interface to interconnect the agitator means to a control unit and/or driving unit. The dispensing device may comprise at least one storing means to hold information about the material stored in the compartment. The displaceable blend may be designed such that it is suitable to release the gate valve opening infinitely variable.
A method for dispensing material by a dispensing unit according to the present invention comprises in general the following steps: a Interconnecting a dispensing device comprising a material in a compartment sealingly closed by a gate valve to a control unit by a standardised interface; b Dispensing material stored in the compartment by opening a gate valve opening in function of a signal of a scaling means interconnected to the control unit in that the amount of material which has left the compartment of the dispensing device is determined; c Adjusting the position of the gate valve until full closing of the gate valve opening when a predetermined amount of material to be dispensed is achieved. If appropriate The agitator means arranged in the compartment agitates the material stored in the compartment before or after the gate valve opening is opened. If appropriate information about the material contained in the dispending device stored in a storing means is exchanged with the control means. The information may be exchanged via the standardised interface.
To control the dispensing device a control unit is designed as a pipette for manual dispensing of solid material. The pipette comprises in general a cartridge holding device suitable to be interconnected to a dispensing device according as described above. The pipette may comprise a first driving means to open and/or close a valve gate opening of a dispensing device and a second driving means to activate a conveyor to convey material from the dispensing device. The pipette may further comprise an electronic circuit to control the opening of the valve gate opening and/or the conveying speed of the conveyor. The pipette may further comprise an interface to interconnect the electronic circuit to a signal of a scaling means.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention of excluding an equivalents of the features shown and described or portions thereof in the use of such terms and expressions, but it is recognized that various modifications are possible within the scope of the invention claimed. For a more complete understanding of the present invention, including its features and advantages, reference is now made to the detailed description of the invention, taken in conjunction with the accompanying drawings, in which:
Fig. shows the pipette of
Reference is now made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings.
As visible in
As it can be seen the blend 5 has a bend and is held within the notch by a sleeve 7 surrounding the lower part of the housing 2. Alternative or in addition a further means ma be present to hold the blend in place. Good results have been achieved with ring like elements firmly surrounding the lower part of the blend. The sleeve 7 comprises here a bayonet-type interlocking device 14 (standardized interface) by which the dispensing device 1 may be securely attached to a corresponding interlocking device of a control unit (see
Inside the compartment 3 an agitator 10 is arranged. The agitator 10 comprises a drive shaft 11 arranged rotatable around the central axis (z-axis of the device 1. The drive shaft 11 comprises in the shown embodiment two shovels 12 reaching into the compartment 3. The shovels 12 of the shown embodiment are formed by two elastic wires here made out of stainless steel metal which are designed such that the move along the inner surface of the compartment 3. Depending on the field of application and the material to be dispensed the shovels can have a different shape or can be made out of a different material, e.g. injection moulded plastic.
The drive shaft 11 is in the shown embodiment mounted rotatable around the central axis of the device in a cover 13 which closes the rear end of the compartment 3. At its rear end the drive shaft 11 comprises a standardized interface by which the drive shaft may be interconnected to a clutch of a drive unit (see
In a rack (not shown in detail further dispensing devices 28 are stored. The further dispensing devices hold different materials on stock and may be interconnected to a control unit 20 either manually by hand or by an automated handling system. To avoid mistaking the dispensing devices 28 comprise a tag 29 which holds information about the material and the condition of the material stored in the dispensing device 28. The control unit 20 comprises means to read out and if appropriate modify the information of the tag. Thereby it is possible to significant reduce the risk of mistaking.
To dispense material into a container 25 the container 25 is moved underneath the gate valve opening 4 and on the scaling device 21. In the herein shown embodiment the scaling device 21 is arranged such that it interacts with the container 25 to receive the material. In addition or alternatively a scaling device is incorporated in the bracket 19 interacting with the dispensing device 1 by measuring the amount of material exiting through the gate valve opening 4. Before the material is dispensed, the at least one scaling device 21 is reset. If necessary the agitator within the compartment of the dispensing device 1 is activated by the CPU to disperse the material stored in the compartment. After that, the gate valve opening 4 is opened sufficient by retracting the blend 5 until material starts to trickle through the opening 4. The amount of material which has left the dispensing device is determined by the scaling device 21 and the information is made available to the CPU 27 for comparison to the total amount to be delivered. If necessary the conveyor means within the dispensing unit is activated to support the trickling of the material. The opening of the gate valve 4 is adjusted by the CPU 27 by the position of the blend until full closing when the predetermined amount of material to be dispensed is achieved.
The functioning and the interaction of the dispensing device 1 and the pipette 30 are now described more detailed with reference to the
Inside the housing 32 the pipette 30 comprises a driving means, here in form of an electro-motor 37 and a power supply in form of a batter pack 38. The electro-motor 37 is interconnected at its lower end to a clutch 39 suitable to be engaged with a standardised interface 13 of the drive shaft 11 of the cartridge 1 when inserted into the cartridge holding device 31 (see
The quick connector 42 comprises a connector sleeve 43 with radial bores 44 in which a first row of radially displaceable spheres 45 are arranged. The spheres 45 protrude in an inner position above the inner surface 46 of the connector sleeve 43. The bores 44 have at their inner end a smaller diameter such that the spheres 45 may not fall out in this direction. A locking sleeve 47 surrounds the connector sleeve 43 on the outside. The connector sleeve 43 is arranged axially displaceable (z-direction with respect to the housing 32 and comprises on the inside a circumferential groove 48 into which the spheres 45 may be displaced radially outwardly when the locking sleeve 47 is in a first rear position, when the circumferential groove 48 is aligned with the spheres 45. In this position the dispensing device 1 ma be inserted into the cartridge holding device 31. In the herein shown embodiment the interlocking 14 of the cartridge 14 comprises a disk-like member 16 and a circumferential counter locking groove 17. When the interface means 14 is in contact with the connector sleeve 43 the locking sleeve 47 is moved in a second position where it locks the spheres 45 in an inner position engaged with the counter locking groove 17 of the cartridge 1. If appropriate the locking sleeve 47 is spring loaded such that it must be actively retracted into the first direction where the dispensing device 1 may be inserted.
In engaged position (see
The axially displaceable bushing 40 and the electro motor 36 are interconnected by a cross-bar 53 to an in its length adjustable lifting rod 52. In the herein described embodiment the batter pack 38 comprises a central opening 60 in which lifting rod 52 is arranged. The lifting rod 52 comprises a lower part 54 and an upper part 55 which are connected to each other through a threaded bushing 56 with two antridromic threads 57, 58. The threaded bushing 56 is interconnected to the adjusting gear 59 by its hexagonal outside shape. A rotation of the face gear 36 is transmitted via the adjusting gear 59 onto the threaded bushing 5 whereby the upper and the lower part 54, 55 are screwed into or out of the threaded bushing 56 and the over all length of the lifting rod 52 is adjusted. The upper part 55 of the lifting rod 52 is interconnected by a lateral pin 63 to a ramp 64 of the control button 33. When the control button 33 is pressed inwardly the ramp 64 acts onto the lateral pin 63 and the lifting rod 52 is raised upwardly as indicated by arrow z1 (see Detail E of
When the control button 33 is pressed an electrical switch 65 is actuated and the lifting rod 52 is lifted via the interaction of the ramp 64 and the lateral pin 63. The electrical switch 65 is interconnected to an electronic circuit which actuates an electromagnet 67 arranged inside the housing 32 above the rear end of the lifting rod 52. In that the lifting rod 52 is lifted, a holding disc 65 arranged at the rear end of the lifting rod 52, is attracted and finally gets in contact with the electromagnet 67 where it is securely held until the electro-magnet 67 is switched off.
By the first turning knob 34 it is possible to adjust and determine via the electronic circuit the time the electromagnet 67 is actuated and thereby how long the gate valve opening 4 remains open. By the second turning knob 35 the rotation speed of the electro motor 37 and the thereto interconnected agitator 10 of the inserted cartridge 1 is adjusted.
The electronic circuit and the electric motor 37 are supplied by the batter pack 38. The batter pack 38 is preferably designed as a rechargeable batter pack 38. Alternatively or in addition it is possible to provide electric power by an external power supply which is e.g. interconnected to an appropriate socket or cable connection.
In a further embodiment the electronic circuit can be equipped with reading means and processing means to read out and process information of an inserted cartridge 1, e.g. stored in form of an electronic tag 29 (see
In stead of the described lifting mechanism 52 the gate valve opening can be opened and closed by a servo motor which is interconnected to the electronic circuit and triggered by a control button. Thereby it becomes possible to adjust the opening of the gate valve opening ver accurately. In that the gate valve opening 4 can be adjusted infinitely it becomes further possible to reduce the flow rate against the end of a dispensing cycle in that the gate valve opening 4 is reduced.
The cartridges 1 may further comprise means (not shown in detail by which the can be held in an external cartridge holder (not shown in detail for holding and storing of several similar or different cartridges. The means are preferably designed such that the cartridges can be inserted into the cartridge holding device 31 of the pipette 30 without the need of manual handling of the cartridges. The holding means may e.g. be designed as a snap connection holding the cartridges only up to a certain level. If appropriate the dispensing device may be incorporated as a fixed element into the pipette.
| Number | Date | Country | Kind |
|---|---|---|---|
| 11/131975 | May 2005 | US | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2006/003457 | 4/13/2006 | WO | 00 | 9/29/2008 |
