DEVICE FOR OPENING FLIP CAP CONTAINERS

Abstract: Device for opening flip cap containers (6) where the flip cap (9) is opened by turning a lever (1). The lever (1) has a holding device for the flip cap (9). This holding device is preferably a hook (2) to engage a projection (10) provided at the flip cap (9). The invention also describes levers which can simultaneously open and/or close several flip cap containers.

Description: Device for opening flip cap containers The invention addresses a device for opening flip cap containers, comprising - a receptacle for the containers where said containers are held, - a lever that is rotatably mounted to an axis and has a device for attaching flip caps, - a drive unit for said lever which is attached to said lever and rotates it around said axis, and - a control means for the drive unit. The procedure of opening and closing flip cap containers has gained particular importance in the field of automated analysis where users handle a great number of containers which have to be closed after use in order to avoid evaporation of liquid or any other negative effect on the liquid contained in said container. Prior art knows a number of analysis instruments where containers with reagent liquids are placed in the automated analyzers. The user then has to manually open and close these containers. An improvement over this manual procedure is the device described in European patent application EP-A-0 523 425. Said device has a receptable for reagent containers which has elements for holding the reagent containers and a lid rotatably mounted to the receptable. The reagent container is opened and placed in the receptable and closed by means of the lid attached to said receptacle. The lid is provided with a lever arm on the side of the axis of rotation facing away from the lid. In order to open the lid, a special device is used to exert pressure on the lever arm in order to open the lid. The device disclosed in European patent application EP-A-0 523 425 has the disadvantage that the lid is fixed to the instrument. The device of this application, hence, only enables the use of containers which are particularly designed to match the lid provided in the instrument. Condensation or other types of carry-over may cause residual liquid to adhere to the lids that are provided in the instrument. If the user now exchanges a reagent container for one clinical parameter for a container of another clinical parameter, the residual liquid may contaminate the new reagent liquid. This type of carry-over may cause highly erroneous analysis results, especially in immunoassays where both antigens and antibodies are employed in the analysis. Moreover, the user must place open containers without a lid into the instrument. However, in the field of clinical analysis, it is common to use reagent containers that are prefilled with standardized liquids. When these reagent containers are used together with the device of EP-A-0 523 425, it is a disadvantage that the user first has to manually open the containers and remove its closure. Further, prior art knows a system where a flip cap container for reagent liquids is provided with a lid having a projection on the side of the axis of rotation facing away from the lid. In order to open the lid, a lever pushes against this projection from the top side. The lid then snaps open. A draw-back of this opening mechanism is that because of the opening process, the hinges of the flip cap containers are exposed to a great amount of stress which in turn greatly limits the number of opening and closing procedures. Iζ for example, one uses reagent containers where a relatively great amount of force is required for opening in order to avoid undesired opening, the projection must be relatively large in order to ensure sufficient levering action. However, a relatively large projection limits the convenience of container handling and increases the space required in the analyzer. It was an object of the invention to provide a device to open and close containers which have flip caps. It was a particular object to provide a device for opening flip cap containers where the opening of the containers exposes the hinges of the containers to a minimum amount of stress. It was another object of the invention to provide a device where it is also possible that one container can be closed and that two or more containers can be simultaneously or successively.be opened. Yet another object was to provide a device for opening flip cap containers which requires a relatively small amount of space and which allows the reagent containers to be packed in a small and tightly fitting packaging. The invention now proposes a device for opening containers with flip caps, comprising the following elements: - a receptable for the containers where said containers are held, - a lever that is rotatably mounted to an axis and has a device for attaching flip caps, - a drive unit for said lever which is attached to said lever and rotates it around said axis, and - a control means for the drive unit. Moreover, the invention proposes a system for providing reagents that comprises the following elements: - an arrangement of reagent containers with flip caps where the reagent containers are provided in receptacles, - a pipettor, - a lever with a device for holding flip caps, said lever being mounted so as to rotate around an axis, - a drive unit for the lever which rotates said lever around said axis, - a control means for the drive unit and the pipettor. Moreover, the invention proposes a method for opening flip cap containers where a container is brought into a receptable where it is held; the flip cap is then brought into contact with a lever by which it is held; subsequently, the container is opened by rotating the lever around an axis which runs essentially parallel to the axis of the flip cap. A device for opening containers is preferably used in automated analyzers or in connection with such instruments as the user here encounters the problem that it is necessary to open a great number of containers to provide an analyzer with liquids. A possibility for closing the containers is also of importance to avoid evaporation or contamination of liquid. Liquids as understood in this invention are in particular reagent liquids, washing liquids, buffer solutions, and also sample liquids. Flip cap containers according to the invention have a capacity of a few milliliters up to a few hundred milliliters. The flip cap containers have a storage container and a flip cap. The flip cap is either directly attached to the container via a hinge or it is provided at a top part that is connected to the container by simple placing, on screwing, or welding. Said flip cap containers are already known in prior art as reagent containers or as containers used in daily household work. The device of the invention is particularly suited for opening and closing containers as they are described in German patent application P 44 19116.2. This application refers to the complete contents of P 44 19 116.2. A device of the invention has a receptable for said flip cap containers in which the containers are held. Such a receptacle can, for example, be a recess into which the container is placed and where it tightly fits. The receptacle should avoid displacement of the container on a plane running perpendicularly to the container axis. In many cases, it is sufficient if the container is held such that it cannot rotate around the axis of its flip cap. In a container with a square cross section, this can be achieved by means of two walls which rest against the container walls parallel to the flip cap axis. In a preferred embodiment of the instrument, the opening mechanism exerts none or only little force onto the container in direction of its longitudinal axis. It is thus not necessary to hold the container in this spatial direction, e.g. by fixing the container in its receptable. In practical embodiments, however, it may be advantageous to fix the reagent container in its position to prevent its being pulled out of the receptacle by the opening device. This can be accomplished in that hold-down means exert pressure onto the top part of the flip cap container. A device in accordance with the invention for opening flip cap containers also comprises a lever which is mounted so as to be rotatable around an axis and also has a holding device for the flip cap. This lever can, for example, have the shape of a rod or plate. The one end of the lever is located on the axis or in the vicinity of the axis while the other end is remote from said axis so as to describe a circular movement when rotating around the axis. The lever has a holding device for the flip cap. This holding device can be a hook, for example, which engages a projection of the flip cap. Instead of the hook, it is also possible to provide a rod which is pushed below the projection of a flip cap container and moved to open said flip cap. Said axis to which the lever is attached is rotated through the action of a drive unit. Such a drive unit can be a step motor, for example. It is, of course, also possible to use other motors while it is advantageous for practical reasons that a transmission transmits the rotating movement of the motor onto the axis. It is thus possible to generate relatively high momentum necessary to open the containers even when small motors are used. When a container as described in Germany patent application P 44 19116.2 is opened for the first time, it is necessary to have a momentum in the order of magnitude of 0.4 Nm. In a preferred embodiment, the lever to open the reagent containers is attached to the axis via a spring. When closing the containers with this lever the lid is snapped onto the top part of the closing without surmounting a barrier which most flip caps show before the flip cap is totally closed. From this position the force necessary to execute repeated openings can be smaller than the force necessary for the first time opening from a totally closed position. A lever that is provided with several hooks can be used to open several reagent containers at the same time. However, if the device is to be provided with a relatively weak motor, the lever may first open and close all containers individually so that it is not necessary to generate a great force for the first time opening of several containers. A control means is provided for the drive unit to execute all movements necessary for opening the container. The control means preferably comprises a micro processor and a corresponding interface to control the drive unit. Corresponding control means for motors, especially step motors, are commonly known in prior art. In a preferred embodiment of the device, the axis of rotation of the flip cap and the axis of rotation of the lever are essentially parallel to each other if the container is in the receptable. In this arrangement, torsion of the hinges is avoided. It is particularly advantageous if the axis of rotation of the lever and the one of the flip cap be provided in spatial vicinity. In such an embodiment, translational forces exerted onto the flip cap container are almost avoided which in turn reduces the mechanical stress exerted on the hinges. In order to open the container, it is necessary that the part of the flip cap, which is facing away from the axis, is moved through the action of the lever. In a preferred case, the flip cap has a projection at which the lever can engage, said projection being provided at the side facing away from the hinge. In a simple and efficient embodiment of the lever, the latter has a hook engaging the projection of the flip cap. This procedure of engaging can principally be accomplished in two ways. In a first possibility for bringing flip cap and lever in contact with one another, either the container or the lever are rigidly mounted. Container and lever are moved in a direction perpendicularly to the axis of rotation of the lever and parallel to the flip cap surface until the lever engages the projection at the flip cap. In a second possibility for bringing lever and flip cap into contact with one another, lever and flip cap are moved parallel to the axis of rotation within a common plane so that the hook moves above the projection at the flip cap. In this second procedure, the drive unit for the lever is preferably provided with the possibility to move the lever in a spatial direction parallel to the axis of rotation of the lever. Moreover, a lever can be improved in that it is provided with a solid element between hook and its attachment to the axis of rotation. Said element is in direct vicinity to the surface of a flip cap when the lever is in a position in which the hook engages the projection of the flip cap. Advantageously, this element is a rail or an abutment which is attached to the hook such that it comes to rest above the flip cap in the vicinity of the hinge. By the above described arrangement, it can be accomplished that the container is essentially not pulled out of its receptable during the opening. When the lever is turned, it may be that the container is slightly lifted up; however, rail or abutment restrict this movement out of the receptacle. It is, of course, possible to provide several levers on one axis of rotation so that several containers may be simultaneously opened and closed. A requirement of such an embodiment is that the containers be arranged next to one another so that the axes of their flip caps are located essentially on one straight line. Owing to the distances between the levers on the axis and the width of the hooks at the levers, it is possible to design an opening device where moving of the axis in its longitudinal direction is used to control whether individual containers of the arrangement are to be opened or closed or whether this applies simultaneously to all containers. In many conventional automated analyzers, the reagent containers are located on rotors, i.e. the receptacles for the containers are arranged on disks which move around their axis while being controlled by the analyzer. One segment of this disk can hold one or several containers. If several containers are provided on one segment, it is preferred in accordance with the invention that the containers be arranged adjacent to one another so that the axes of their flip caps come to rest essentially on a straight line which intersects with the axis of rotation of the disk. When a pipettor is integrated in the already described device for opening containers, it is possible to provide a system for making reagents available. A system of this kind must also comprise a control means for both the pipettor and the lever drive which controls the movement of said lever, and if necessary, the movement of the containers, the movement of the pipettors, and the pipettor movements of drawing in and releasing liquids. Moreover, the invention comprises a method where lever and flip cap are brought into contact with one another such that the lever first turns into a position where lever and flip cap surface are essentially parallel to one another while hook and projection at the flip cap are located essentially on one common plane, however offset with respect to each other such that the hook does not engage the handle. Subsequently, a relative movement of lever and reagent container on said plane, causes the projection of the flip cap to be pushed into the hook and the hook is rotated around its axis such that the flip cap container is opened. If the reagent containers are located on a rotor, certain parts of the rotor can be provided with elements, e.g. pins, for positioning the rotor. These elements are preferably provided at the outside of the rotor while their longitudinal axis runs parallel to the axis of the rotor. Outside the rotor, provision may be made for a fork which is moved over the positioning element such that the rotor is arrested in a given position. The elements for positioning are preferably arranged such that the rotor can be arrested in positions in which an opening mechanism has access to reagent containers positioned on the rotor. Moreover, the elements may serve to select positions where reagents can be pipetted out of the container. In another embodiment, the reagent containers are located on a rotor which has the shape of a circular ring. Inside this circular ring, provision is made for a device for opening containers. This device can in turn be mounted so as to be rotatable around the axis of the rotor and have a motor for executing a rotation around this axis. Rotor and opening device can either be coupled to each other so that opening device and rotor rotate together, or their rotating movements are not coupled so that both can perform independent movements. In such an arrangement, it is preferred that an opening procedure comprise the following steps: - the lever of the opening device assumes a vertical position. - the reagent rotor turns such that one or several reagent containers come to rest beneath the lever. - the lever assumes a horizontal position such that it comes to rest parallel to the top side of the flip caps. - the rotor with the reagent containers turns such that the projections of the reagent containers are moved into the hooks of the lever. - the lever turns from its horizontal position into a vertical position thus opening the lid. In the open position, a liquid or the like may be removed from the containers by means of pipetting. In a preferred manner, the lever is not moved away from the flip cap, but the hooks continue to engage the projections of the flip caps. Once the pipetting is completed, the lever returns into a horizontal position thus closing the containers. Due to a turning movement of the rotor or the opening mechanism, lever and reagent containers are moved away from each other such that the hooks disengages the container projections. The lever of the opening mechanism can now move upwardly out of its horizontal position without opening the flip caps. In this position, opening device and rotor can move without contacting one another. An advantage of the above described embodiment is that the lever must not necessarily execute a linear movement in direction of its axis of rotation. For this structural design it, hence, suffices to provide one single motor for the opening device which serves to execute a rotation of the lever around its axis. The motor necessary to turn the reagent rotor is already provided in all conventional analyzers. The above mentioned known prior art only knows an open and closed position of a flip cap. In general practice, this is a disadvantage as especially the opening of the lid requires a relatively great amount of force, especially if a flip cap with a large opening is necessary to enable pipetting with a disposable plastic tip. In the present device, it is, however, also possible to advantageously use flip cap containers which feature three or more resting positions of the flip cap. The flip cap described in German patent application P 44 19116.2 for example features three resting points. In a first resting point, the lid is completely closed; in another resting point it is opened by a certain angle with respect to the closed position; moreover, there is a third position in which the lid rests on the closure where it is kept down by a specially designed hinge in order to avoid evaporation of liquid in the container. The device underlying this invention is also designed to move the flip cap out of or into this third position. The possibility of moving a flip cap into this position features the advantage that an opening out of this position requires only a relatively small amount of force. Another improvement of the device in accordance with the invention can be achieved if a spring serves to connect the lever to the drive unit. It is thus possible to have a more uniform distribution of the stress load to which the drive unit is exposed during opening. The invention further addresses a method for opening containers with flip caps where the container is placed into receptacle where it is held while the flip cap of the container is then brought into contact with the lever. Subsequently, the flip cap is opened in that the lever is rotated around an axis. When lever and flip cap are brought into contact with each other, it should be possible that a hook provided at the lever engages a part of the flip cap, as described further above. This contacting procedure should generally also include embodiments where a mechanical connection that allows an opening of the flip cap is provided between lever and flip cap. In a preferred manner, the invention proposes a device where the drive unit simultaneously drives several levers which are provided next to each other on one axis. With this embodiment it is possible to simultaneously open and close several containers which saves processing time when a great number of containers is to be processed. The above described embodiment can further be improved when the levers are provided with hooks of different widths. It is thus possible to allow a selected opening and closing of individual adjacent containers by moving the axis together with the levers in a direction parallel to said axis. Such an arrangement can be used to open and close several containers simultaneously. Moreover, the movement of the axis can be used as a control means so that only selected containers are processed by moving the hooks at the levers. The described embodiment thus allows to selectively increase the throughput and selectively access to individual containers. As compared to the devices known in prior art, it is an advantage of the device of the invention that flip cap containers can be opened and closed while the mechanical stress to which the hinges of the flip caps are exposed is reduced. This in turn accounts for a much higher number of opening and closing cycles for each container. Another advantage of the invention lies in the fact that one single drive unit can be employed to access several containers. Moreover, with the device of the invention it is possible to selectively move the flip caps of containers such that it is possible to set several defined end positions. The present invention is now further illustrated with reference to the following figures. Figure 1 : Diagrammatic representation of a lever with flip cap containers Figure 2: DJΛgrammatic representation of lever positions and the resulting opening functions Figure 3: Row diagram for the opening and closing procedure Figure 4: Positions for movements of the lever parallel to the axis of rotation of the lever Figure 5: Positions of rotation of the lever Figure 6: Construction drawing of an opening mechanism in a top view Figure 7: Construction drawing of an opening mechanism in a lateral view perpendicularly to the axis of the opening mechanism Figure 8: Construction drawing giving a lateral view in direction toward the axis of the opening mechanism Figure 1 shows the principle function of an opening device for flip cap containers. Lever (1) is provided with two bores (3, 4). The first bore (3) is provided for an axis which serves as the axis of rotation of lever (1). The second bore (4) is provided to receive an element to execute a rotation of lever (1) around axis (3). Lever (1) also has two hooks (2a, 2b) and a rail (5). In order to open the containers, lever (1), as illustrated in Figure lc, is moved above the flip caps so that hook (2a) engages projection (10) of a reagent container. In order to move lever (1) into this position, the lever begins its movement at a position that is remote from the flip cap container (6) and is rotated such that its surface is essentially parallel to the surfaces of the flip cap. Subsequently, lever (1) is moved above the flip caps in direction of arrow (11) so that hook (2a) engages projection (10) of a flip cap container (6). Then, lever (1) is rotated in direction of arrow (12) around axis (3) in order to open the snap-top container. Depending on the position of lever (1) in the direction indicated by arrow (11), said lever opens one or two containers. During this process it is advantageous if the axis around which lever (1) is rotated and the axis given through hinge (13) of the flip cap approach one another as close as possible. The opening procedure can be further supported in that the rail (5) is provided at the top of flip cap container (6) preferably in the vicinity of hinge (13). Thus, the container cannot be pulled out of the receptacle during the opening. Rail (5) is preferably arranged such that it is located above the flip cap (6) in the vicinity of hinge (13) as depicted in Figure lc. Figure 2 is a top view of two flip cap containers with a lever there above. The lever itself is, however, not represented, but only two holding devices (2a, 2b) at which the one or several levers would be attached. Figure 2 shows that with a favorable selection of hooks (2a, 2b), it is possible to use one single lever to open all flip cap containers at one time and selectively access the individual flip cap containers while the containers are positioned within a row. Figure 2a shows the two hooks (2a, 2b) in a position where a rotational movement of the lever leads to an opening of the two flip cap containers (6). If the lever is moved toward the direction of arrow (11), i.e. toward the left side as indicated in Figure 2b, the rotation of the lever only opens the flip cap container designated as Rl. It is possible to selectively open flip cap container R2 if the lever is moved in the direction of arrow (11), i.e. toward the right side, so that the hook (2a) engages only projection (10) of flip cap container R2 (Figure 2c). A similar functionality can be accomplished if the hooks (2a, 2b) have the same width. However, the embodiment represented in Figure 2 has the advantage that the necessary movement of the hooks to accomplish the three represented opening variants in direction of arrow (11) is smaller. The principle illustrated here can, of course, also be applied to a larger number of hooks. Figure 3 shows a flow diagram for opening and closing flip cap containers. The positions given in this flow diagram are represented in Figures 4 and 5. Light barriers are provided to check whether or not the individual positions have been accessed. To do this, the eccentric disk (20) of motor (19) is provided with a notch which is controlled by light barrier (30). A second motor (31) is provided to control the movement of lever (1) in direction of the axis of rotation. The lever carries a flag that is mechanically connected to it and which is checked by two light barriers at position 1 (32) and position 2 (32). Figure 6 is a top view of the device in accordance with the invention. An arrangement (16) of flip cap devices (6) is located in receptacle (15) in which the arrangement (16) is held in position at two sides. Figure 7 is a lateral view of the device parallel to axis (17) of the lever. In this Figure it can be seen that the hooks (2) are located above the flip cap containers. Figure 8 is a lateral view of the device perpendicular to the axis of rotation of the lever. It can be seen how motor (19), via eccentric disk (20), moves a connecting rod (21) which in turn moves, via lever arm (18), the lever and, hence, the hooks (2). List of reference numerals (1) Lever (2) Hook (3) Bore for axis (4) Bore for engaging element (5) Rail (6) Flip cap container (7) Storage container (8) Top part (9) Flip cap (10) Projection (11) Arrow parallel to axis of rotation (12) Arrow indicating sense of rotation (13) Hinge (15) Receptacle (16) Arrangement of flip cap containers (17) Axis (18) Lever arm (19) Motor (20) Eccentric disk (21) Connecting rod (30) Light barrier (31) Second motor (32, 33) Positions 1 and 2

Claims: Claims 1. Device for opening containers (10) with flip caps, comprising - a receptacle for the containers where said containers are held, - a lever that is rotatably mounted to an axis and has a device for attaching flip caps, - a drive unit for said lever which is attached to said lever and rotates it around said axis, and - a control means for the drive unit. 2. Device according to claim 1 where the axis of rotation of a flip cap and the axis of rotation of a lever run essentially parallel to one another if the flip cap container is held in the receptacle. 3. Device according to claim 1 where the device for attaching the flip caps is a hook. 4. Device according to claim 1 where the drive unit can move the lever additionally in a spatial direction parallel to the axis of rotation of the lever. 5. Device according to claim 1 having a lever with several devices for attaching flip caps. 6. Device according to claim 1, where the receptacle for containers can receive several containers such that the axes of the flip caps are essentially located on one line. 7. Device according to claim 1, where several receptacles for containers are provided on one rotor, and the rotor is mounted rotatably around an axis which runs essentially perpendicular to the axis of rotation of the lever. 8. Device according to claim 1, where the lever (1) is provided with a rail (5) located in spatial vicinity to the flip cap surface when lever and flip cap are in contact with one another. 9. System for making available reagents, comprising - an arrangement of reagent containers with flip caps where the reagent containers are provided in receptacles, - a pipettor, - a lever with a holding device for containers, said lever being mounted rotatably around an axis, - a drive unit for the lever which rotates said lever around said axis, - a control means for the drive unit and the pipettor. 10. Device according to claim 1, where lever (3) can access desired position with respect to the axis of rotation, namely a first position where the holding device of the lever holds the top of a flip cap container, a second position where the flip cap is opened at an angle of 80 - 150° with respect to its closed position, and a third position where the flip cap rests on the top part of the container. 11. Device according to claim 1, where a spring is used to connect the lever to the drive unit. 12. Device according to claim 1, where the drive unit simultaneously drives several levers that are located adjacent to one another on one axis. 13. Device according to claim 12, where the levers are essentially located on one plane. 14. Device according to claim 12, where the levers have hooks of different widths. 15. Method for opening flip cap containers comprising the steps of - bringing the flip cap container into a receptacle in which the container is held in position, - bringing the flip cap container in contact with a lever so that the flip cap is held in position by the lever, - rotating the lever around an axis which runs essentially parallel to the axis of the flip cap in order to open the container. 16. Method according to claim 15, where the lever is moved parallel to the axis of the flip cap in such a way that the hook provided at the lever is moved over a projection of the flip cap in order to establish contact with the lever. 17. Method according to claim 15, where contact between lever and flip cap is accomplished such that the lever first assumes a position where lever and flip cap surface are essentially parallel to each other; hook and projection at the flip cap are then moved on a common plane such that the hook does not engage the projection; subsequently, the projection of the flip cap is moved into the hook of the lever due to a relative movement of lever and reagent container on said common plane; the lever is then rotated around its axis so that the flip cap container is opened.

Inventors: SATTLER STEPHAN, SATTLER, STEPHAN
Applicants: BOEHRINGER MANNHEIM GMBH, SATTLER STEPHAN, SATTLER, STEPHAN
Application year: 1995
Main classification: G01N35
IPC codes: B01L11, G01N35