Sample container closure method for automatically closing open top end of sample container by closure cap, movable cap gripper, and sample container closure system

Abstract

To provide a method and an apparatus capable of automatically and surely capping and / or recapping a sample container.SOLUTION: Provide is a method including the steps of: gripping an upper portion of a closure cap at its outer periphery by a cap gripper having at least two gripper fingers including respective upper pushing ledges extending at least partially over recesses provided by lateral gripping surfaces; and pushing the closure cap into an open end of a sample container by the upper pushing ledge. And provided are each movable cap gripper for automatically closing the open end of the sample container by the closure cap, as well as each sample container closure system.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Generally, the present invention relates to the technical field of sample analysis, such as the analysis of biological samples, and more particularly to the technical field of high throughput analysis of biological samples.

[0002] In particular, the present invention relates to a method for automatically closing the open end of a sample vessel or reaction vessel with a closure cap, as well as a respective movable cap gripper as an instrument for automatically closing the open end of a sample vessel with a closure cap, and a sample vessel closure system equipped with such a cap gripper.

[0003] In other words, the present invention relates inter alia to procedures and devices used in the course of analytical, pre-analytical or post-analytical processing, during which a sample container, such as a sample tube, needs to be closed, also called "capped", by a suitable closure cap, either for initially sealing or capping the contents of the sample container after its insertion or for resealing or re-capping the contents of the sample container during processing, and / or needs to be closed again after opening, also called "reclosed" or "recapped". As a specific example, the sample container may be used as a sample container for a thermal cycling structure or device (also called thermocycler or thermal cycler) for carrying out chemical and / or biological reactions, such as for example the polymerase chain reaction (PCR), such a thermal cycling device typically comprises at least a sample mount for receiving one or more sample containers or reaction vessels, a heat pump with a heat sink, and a control unit for controlling the heating and cooling of the heat pump during thermal cycling. [Background technology]

[0004] For the analysis of biological samples, biological samples are usually taken from patients by medical personnel in hospitals or private practice for laboratory analysis, for example to determine the concentration levels of different components in the taken sample. Thus, the terms "sample" and "biological sample" refer to materials that can potentially contain the analyte of interest, and biological samples can be derived from biological sources such as physiological fluids including blood, saliva, ocular lens fluid, cerebrospinal fluid, sweat, urine, stool, semen, milk, peritoneal fluid, mucus, synovial fluid, ascites, amniotic fluid, tissue, cultured cells, etc., and the sample can be considered to contain a particular antigen or nucleic acid.

[0005] In many biological, biochemical, diagnostic or therapeutic applications, it is essential to be able to accurately determine the amount or concentration of a particular substance or compound in a biological sample contained in a reaction mixture, such as a particular antigen or nucleic acid as mentioned above. In order to be able to achieve this goal precisely, methods have been developed over the years, such as the polymerase chain reaction (PCR), widely known for example in the form of real-time PCR, digital PCR (dPCR) or multiplex PCR, which allows the in vitro synthesis of nucleic acids in a biological sample, in which DNA segments can be specifically replicated, i.e. a cost-effective way to copy or amplify small segments of DNA or RNA within a sample. The development of these methods for amplifying DNA or RNA segments has brought enormous benefits to genetic analysis, the diagnosis of many genetic diseases or the detection of viral load. Thermal cycling, also commonly referred to as thermocycling, can be utilized to provide heating and cooling of reactants in a sample provided in a sample container, such as a reaction vessel for amplifying DNA or RNA segments, where thermocyclers are commonly used to achieve automated procedures for PCR-based diagnostic assays, during which the PCR is performed, the liquid PCR-sample as well as the respective reactants must first be transferred to the sample container before being repeatedly heated and cooled to different temperature levels. During the time of thermal cycling, and after removing the thermocycled sample, for example during an analytical process, the contents of the sample container must be sealed inside the sample container in a fluid-tight manner, for example by a respective closing cap.

[0006] In recent years, there has been a need to process a larger number of samples simultaneously, as well as to perform our analytical, pre-analytical or post-analytical processing more quickly, which has resulted in the development of automated processing systems. For example, in the process of simultaneously monitoring multiple nucleic acid amplification reactions during thermal cycling of biological samples by a thermocycler, known analytical systems have further obtained an excitation light source for applying excitation energy to the nucleic acid amplification reactions in the sample container, and a sensor for simultaneously detecting the light emitted from multiple nucleic acid amplifications. However, due to the various sample tubes and the respective various closure cap designs or models, the handling of the sample containers and their closures becomes more complicated and is often still performed by laboratory personnel, which is tedious, time-consuming, costly and prone to human failure. Therefore, there is a need to perform sample processing faster, cheaper and easier while achieving high accuracy and efficiency.

[0007] In the course of developing devices that can improve sample processing, several attempts have been made to improve the handling of sample containers and their respective closure caps with regard to the closing and / or reclosing of these sample containers, also called capping and re-capping. For example, US Patent Application Publication No. 2020 / 0072858 describes a system and method for automatic closure of sample containers, in which the closure gripper has not only clamping jaws but also a centering piece as an additional component, which must be inserted into the respective recess of the closure cap so that the centering piece of the closure gripper can press the closure cap into the open end of the sample tube. Similarly, US Patent No. 9,505,507 discloses a cap opening and closing mechanism of an automatic analyzer, which comprises a cap chuck set with three or more supports for gripping the cap of a sample tube, and further a support for pressing the cap into the open end of a sample container as an additional component for applying a downward force from above to the cap. However, these solutions lead to a complex structure of the closure gripper having a large number of structural components, which, among other things, increases the manufacturing costs of such equipment and also increases the risk of damage, breakage of the entire equipment, if only one of its structural components fails.

[0008] As further known prior art, WO 2021 / 216931 discloses a gripper device with fingers for gripping the side walls of closure caps for specimen containers, each finger of one particular embodiment of such a gripper having a concave inner contact surface for improving gripping of the periphery of the closure cap and a further recess on the thus structured contact surface separating the contact surface from the inclined upper region of the finger. However, the inclined upper region of the gripper finger in this embodiment is provided to avoid any contact between the upper surface of the closure and the base of the respective jaw member of the gripper device, in particular in the case of slippage between the outer periphery of the closure and the contact surface of the gripper finger. The downward force in this disclosure is therefore applied only by the lateral gripping force of the gripper fingers on the closure, without additional structural components for providing additional downward force. Thus, in the solution presented in WO 2021 / 216931, the already mentioned slippage between the gripper fingers and the closure can occur, which poses a significant risk that the closure cannot be safely inserted into the open end of the specimen container and thus poses a risk of specimen spillage and contamination during processing of the specimen container.

[0009] Due to these and other problems and shortcomings, the prior art proposals presented above are unable to meet the needs of today's users and therefore do not provide a satisfactory solution.Therefore, there is a general need in the current state of the art to provide a method and apparatus that can automatically and reliably cap and / or recapp sample containers in order to make diagnostic assays much faster and therefore cheaper to perform while maintaining or improving accuracy and efficiency. Summary of the Invention

[0010] The present invention addresses the above-mentioned problems by improving a gripping method and device for automatically capping and / or re-capping sample vessels with respective closure caps. According to a first aspect of the present invention, there is provided a method for automatically closing an open end of a sample vessel with a closure cap, the method comprising the steps of: providing an open sample vessel, such as a sample tube having an open end and a closed end, in a held state; providing a closure cap configured to close, e.g. cap or re-cap, the open end of the sample vessel; gripping an upper part of the closure cap at its outer periphery by a cap gripper having at least two gripper fingers movable towards each other, each gripper finger including a distal end having a concave lateral gripping surface for engaging with the outer periphery of the upper part of the closure cap, and at least one gripper finger including an upper push-in ledge extending at least partially over the recess provided by the lateral gripping surface; inserting at least a lower part of the closure cap into the sample vessel by the cap gripper; and pushing the closure cap into the open end of the sample vessel by the upper push-in ledge by moving the cap gripper towards the closed end of the sample vessel until the closure cap liquid-tightly closes the open end of the sample vessel, thereby capping or re-capping the sample vessel. In so doing, the gripping fingers are not only components of the cap gripper that hold the closure cap, but also components that apply a downward force to the upper side of the closure cap in order to push it into the open end of the sample vessel, thus avoiding the provision of additional components for generating the pushing function.

[0011] Further details and explanations regarding the configuration and structure of the above-mentioned cap gripper and closure cap can be collected further below. The above-mentioned method steps are preferably performed consecutively in a predetermined order, and the steps of providing a sample vessel and providing a closure cap are interchangeable.

[0012] According to a particular embodiment of the invention, the top of the closure cap is provided with a surface structure at least on its periphery, and at least one, but preferably each, of the gripper fingers is provided with a surface structure that matches with the surface structure of the top of the closure cap. On that basis, the step of gripping the top of the closure cap comprises an engagement between a surface structure of the periphery of the top of the closure cap and a surface structure of the lateral gripping surface in order to achieve a tight grip between the cap gripper and the closure cap during the moving and inserting steps. Such a surface structure provided on the periphery of the top of the closure cap may be realised in the form of a circular groove or notch, and the matching or mating surface structure of the respective gripper finger may be realised in the form of a mating circular ridge or protrusion or any similar mating / interlocking structure. This allows to ensure a tight grip between the gripping finger and the closure cap, and to avoid any slippage or the like of the closure cap.

[0013] According to a further particular embodiment of the invention, the step of moving the closure cap to the open end of the sample vessel can include placing the lower end of the closure cap at or in the open end of the sample vessel by the cap gripper. In this regard, it is pointed out that the closure cap usually consists of an upper part that can grip the closure cap and a lower part that is inserted into the sample vessel, the upper part including the upper end, i.e. the upper end of the closure cap, and the lower part including the lower end, i.e. the lower end of the closure cap. Thus, by already placing the lower end of the closure cap at the open end of the sample vessel, i.e. on and near or in the open end of the sample vessel, and including already introducing the lower end of the closure cap to some extent into the open end of the sample vessel, the step of moving the closure cap to the open end of the sample vessel allows the lower end of the closure cap to be safely introduced into the open end of the sample vessel.

[0014] According to further particular embodiments of the invention, the step of inserting at least the lower part of the closure cap into the sample vessel comprises additional steps or sub-steps before the closure cap is forced into the open end of the sample vessel. In particular, the step of inserting the lower part of the closure cap into the sample vessel may further comprise the sub-step of loosening the grip of the upper part of the closure cap by moving at least two gripper fingers slightly away from each other in order to disengage the lateral gripping surfaces of each gripper finger from the outer periphery of the upper part of the closure cap. Thus, by loosening the grip of the closure cap, with the lower part of the closure cap already positioned at or in the open end of the sample vessel, the closure cap sits on the open end of the sample vessel, after which the lower part of the closure cap is forced into the sample vessel by the upper pushing ledge exerting a downward force on the upper part of the closure cap. With regard to the optional step of loosening the grip on the top of the closure cap, it is pointed out that the peripheral movement of the gripper fingers outward from each other involves a movement of each gripper finger outward from the closure cap, so that the lateral gripping surfaces of each gripper finger disengage from the outer periphery of the closure cap, but the gripper fingers still provide sufficient lateral guidance for the closure cap to substantially maintain its position and orientation, in particular to maintain the lower end of the closure cap at or within the open end of the sample vessel. As an example of such peripheral movement of the gripper fingers, the degree of movement of each gripper finger away from the closure cap can be in the range of 1 μm to 1 mm. Thus, by loosening the grip as described above, the upper push-in ledge of each finger can come into intimate contact with the closure cap, allowing the downward force provided by the upper push-in ledge to be transferred in a planar manner to the upper end of the closure cap. In this regard, according to further particular embodiments of the invention, the closure cap can have a substantially flat upper or top surface and the upper push-in ledge of the gripper fingers can provide a flat lower surface, such that during the pushing step the upper push-in ledge and the upper portion of the closure cap can come into surface contact with each other, whereby maximum transfer of downward force from the upper push-in ledge to the upper end of the closure cap can be achieved.

[0015] According to a further particular embodiment of the invention, the method further comprises the steps of moving at least two gripper fingers away from each other and away from the inserted closure cap and moving the cap gripper away from the closed sample vessel. These additional steps are after the step of pushing the closure cap into the open end of the sample vessel and allow the cap gripper to move to its initial position before gripping / gripping the next closure cap to be inserted into another sample vessel. These "final" method steps thus allow the cap gripper to be in the starting position for performing the next automatic closure of the open end of the subsequent sample vessel to be closed.

[0016] According to a further particular embodiment of the invention, the step of gripping the top of the closure cap comprises surrounding at least 50%, such as 80% to 90%, of the outer surface of the top of the closure cap by the lateral gripping surfaces of the gripper fingers and the top push-in ledge, thereby ensuring a tight grip between the gripper fingers and the closure cap and also ensuring sufficient transfer of the downward force from the top push-in ledge to the top edge of the closure cap without the closure cap tipping.

[0017] According to a further particular embodiment of the invention, the movement of the gripper fingers towards and away from each other is realized by a pivoting movement of the gripper fingers about a common fulcrum, centering the closure cap on the longitudinal central axis of the cap gripper. More specifically, each finger of the cap gripper comprises a distal end for engaging the closure cap and a proximal end arranged opposite thereto, the proximal ends of the fingers being fixed to each other, for example rotatably about a common axis or fulcrum, whereby the distal ends of the gripper fingers can be pivoted relative to each other about the common pivot point. Thus, centering of the closure cap on the axis common to the cap gripper can be achieved, so that the longitudinal axis of the closure cap can be automatically positioned coaxially with the longitudinal axis of the cap gripper. This can improve the positioning of the closure cap relative to the sample vessel and the transmission of forces to the closure cap by the cap gripper.

[0018] According to a further particular embodiment of the invention, a shoulder is provided between the upper and lower parts of the closure cap, the upper part of the closure cap including a larger periphery than the lower part of the closure cap, where the larger periphery of the upper part of the closure cap can be the same as or larger than the inner periphery of the open end of the sample vessel. Thus, the step of forcing the closure cap onto the open end of the sample vessel includes moving the cap gripper towards the closed end of the sample vessel until the shoulder of the closure cap and the upper edge of the sample vessel contact each other. This results in the lower part of the closure cap being inserted sufficiently into the open end of the sample vessel for the closure cap to seal the sample vessel liquid-tight, the contact between the shoulder of the closure cap and the upper edge of the sample vessel further providing a liquid-tight seal.

[0019] According to another aspect of the present invention, a movable cap gripper for automatically closing an open end of a sample vessel by a closure cap is provided by the present invention, the cap gripper comprising at least two gripper fingers movable towards each other, each gripper finger comprising a distal end having a concave lateral gripping surface for engaging with the periphery of the top of the closure cap, the distal end of at least one gripper finger comprising an upper pushing shelf extending at least partially over the recess provided by the lateral gripping surface. In such a structure, the gripping fingers are not only the components of the cap gripper that hold the closure cap, but also the components that apply a downward force to the top side of the closure cap to push it into the open end of the sample vessel. Thus, the provision of additional components for achieving the pushing function can be avoided. Furthermore, the cap gripper of the present invention can also be used to remove a closure cap from a sample vessel by firmly gripping the top of the closure cap by the gripper fingers and pulling the closure cap out of the sample vessel by frictional forces between the distal ends of the gripper fingers and the periphery of the top of the closure cap. In this regard, it may be useful to replace the gripper fingers with a different type of fingers that are better suited for such decapping.

[0020] According to a particular embodiment of the invention, the lateral gripping surface of at least one gripper finger includes a surface structure configured to match the surface structure of the outer periphery of the closure cap to enable a tight grip between the cap gripper and the closure cap. Such a matching or mating surface structure of the or each gripper finger may be realized in the form of a mating circular ridge or protrusion, or any similar mating / interlocking structure, configured to match the respective surface structure provided on the outer periphery of the top of the closure cap to be engaged, this structure of the outer periphery of the top of the closure cap may be realized in the form of a circular groove or notch, etc. This can ensure a tight grip between the gripping finger and the closure cap and avoid any slippage or the like of the closure cap. Additionally or alternatively, the upper push-in ledge of the gripper finger provides a flat underside to enable a surface contact between the upper push-in ledge and the top of the closure cap, so that a downward force is maximally transferred from the upper push-in ledge to the top end of the closure cap.

[0021] According to a further particular embodiment of the invention, the gripper fingers are connected to each other about a common fulcrum for pivoting the gripper fingers towards and away from each other. More specifically, each finger of the cap gripper comprises a distal end for engaging with the closure cap and a proximal end arranged opposite thereto, the proximal ends of the fingers being fixed to each other, for example rotatably about a common axis or fulcrum, whereby the distal ends of the gripper fingers can be pivoted relative to each other about the common pivot point. Thus, centering of the closure cap on an axis common to the cap gripper can be achieved, so that the longitudinal axis of the closure cap can be automatically positioned coaxially with the longitudinal axis of the cap gripper. This can improve the positioning of the closure cap relative to the sample vessel and the transmission of forces by the cap gripper to the closure cap.

[0022] According to a further particular embodiment of the invention, each gripper finger comprises a generally L-shape, the long side of the L-shape providing a proximal end of the gripper finger arranged to be rotatably fixed, and the short side of the L-shape providing a distal end of the gripper finger as further defined above. Alternatively or additionally, each gripper finger may consist of a body and a contact member at its distal end, i.e. the short side of the L-shape may consist of a part of the body and further of a contact member at its distal end, the contact member including a lateral gripping surface and an upper depression shelf, the contact member being connected to the body part in a removable manner. Thus, the cap gripper may be adapted to different models or structural designs of closure caps, for example the surface structure of the lateral gripping surfaces of the gripper fingers may be selected along the respective surface structure of the outer periphery of the closure cap to be inserted into the desired sample vessel. Also, since sample vessels of different sizes or shapes require closure caps of different sizes or shapes, different shapes or sizes of recesses in the lateral gripping surfaces of the gripper fingers may be selected to achieve a sufficiently tight engagement between the cap gripper and the selected closure cap. It is pointed out here that depending on the required switching frequency, the switching of the contact members of the gripper fingers may be handled manually or automatically.

[0023] According to a further aspect of the invention, a sample vessel closure system for automatically closing an open end of a sample vessel having a closure cap is provided by the invention. Such a system comprises a holder for the sample vessel to be closed, a closure cap for the sample vessel to be closed, which closure cap may exhibit a structure as already defined above, and a cap gripper as already defined above. Alternatively or additionally, the distal end of each gripper finger is adapted to a selected model of the closure cap, the surface structure of the periphery of the closure cap and the surface structure of the lateral gripping surface of each gripper finger may be configured to match each other, as already explained in more detail.

[0024] In other words, the cap gripper of the present invention comprises a feature that interfaces with the top of the closure cap, which may for example be a so-called flex cap, so that no excessive lateral / side force is required to hold the closure cap in place during transport and recapping, and the structural design of the cap gripper emphasizes a downward pressing force during capping or recapping. Thus, the gripper fingers of the cap gripper of the present invention have been developed to interact with the closure cap to avoid damage during capping or recapping. Thus, compared to the known prior art, such damage avoidance has been integrated into at least one or each of the gripper fingers, and a simpler structure has been applied. In particular, a simpler workflow can be implemented, since the gripper fingers do not necessarily have to first release the cap before the sample container can be sealed. Also, no additional or separate moving parts are required for the gripper fingers to perform the capping or recapping function.

[0025] Typically, an automated processing system, such as an analytical, pre-analytical or post-analytical processing system, commonly used in state-of-the-art laboratories to automatically process biological samples, may comprise an instrument for performing the above-mentioned method, such as a cap gripper as described above, or an entire sample container closure system as described above. Here, the term "laboratory equipment" or "equipment" in a laboratory encompasses any device or equipment component operable to perform one or more processing / workflow steps on one or more biological samples, and also encompasses analytical equipment, pre-analytical equipment, and post-analytical equipment. Thereby, the expression "processing step" refers to a processing step that is physically performed, such as performing a specific step of PCR execution. The above-mentioned method steps may be controlled by a control unit of such an automated processing system, which may also control any kind of operation or monitoring of the above-mentioned devices and their components, and the term "control unit" as used herein encompasses any physical or virtual processing device, such as a CPU, and may also control the entire equipment, or the entire workstation including one or more laboratory equipment, so that the workflow and workflow steps are performed. The control unit may, for example, be loaded with different types of application software and instruct the automated processing system or its specific instruments or devices to perform pre-analytical, post-analytical and analytical workflow / workflow steps. The control unit may receive information from the data management unit regarding which steps need to be performed with a specific sample or sample container. Furthermore, the control unit may be integral with the data management unit, may be included in a server computer, and / or may be part of one instrument or distributed across multiple instruments of the automated processing system. The control unit may, for example, be embodied as a programmable logic controller that executes a computer-readable program with instructions to perform operations.Here, a user interface may further be provided to receive such instructions by the user, and the term "user interface" as used herein encompasses any suitable application software and / or hardware for interaction between an operator and a machine, including but not limited to a graphical user interface for receiving commands from an operator as input and providing feedback and conveying information thereto. Also, a system / apparatus may expose several user interfaces to provide services to different types of users / operators.

[0026] As used herein and in the appended claims, the singular forms "a," "an," and "the" include the plural unless the context clearly indicates otherwise. Similarly, the words "comprise," "contain," and "encompass" are to be interpreted inclusively rather than exclusively, i.e., "including but not limited to." Similarly, the word "or" is intended to include "and," unless the context clearly indicates otherwise. The terms "plurality," "multiple," or "multitude" refer to an integer multiple of two or more, i.e., 2 or >2, while the terms "single" or "sole" refer to one, i.e., =1. Furthermore, the term "at least one" should also be understood as one or more, i.e., 1 or >1, which are also integer multiples. Thus, words using the singular or plural also include the plural and singular, respectively. Additionally, the words "herein," "above," "previously," and "below," and words of similar import, when used in this patent application, shall refer to this patent application as a whole and not to particular portions of this patent application.

[0027] Furthermore, certain terms are used for convenience and are not intended to limit the invention. The terms "right," "left," "up," "down," "under," and "above" refer to directions in the figures. The terms include those terms explicitly mentioned and their derivatives and terms with similar meanings. Spatially relative terms such as "beneath," "below," "lower," "base," "above," "upper," "top," "proximal," and "distal" may also be used to describe the relationship of one element or feature to another element or feature as shown in the figures. These spatially relative terms are intended to encompass different positions and orientations of the device during use or operation in addition to the positions and orientations shown in the figures. For example, if the device in the figures is turned upside down, elements described as "below" or "below" other elements or features would become "above" or "above" other elements or features. Thus, the exemplary term "below" can encompass both above and below positions and orientations. The device may be oriented in other ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, descriptions of movement along and around various axes include various spatial device positions and orientations.

[0028] To avoid repetition of illustrations and descriptions of various aspects and exemplary embodiments, it should be understood that many features are common to many aspects and embodiments. The description of certain embodiments of the present disclosure is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Although certain embodiments of the present disclosure and examples thereof are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present disclosure, as those skilled in the relevant art will recognize. Certain elements of the foregoing embodiments may be combined with or substituted for elements of other embodiments. Furthermore, although advantages associated with certain embodiments of the present disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and it is not necessary for all embodiments to exhibit such advantages to be included within the scope of the present disclosure as defined by the appended claims. Where applicable, technical features from an apparatus or system claim may be used in the method or course of use described in the claims, or vice versa. The omission of an aspect from the description or figures does not mean that the aspect is missing from the embodiment incorporating the aspect. Instead, the aspect may be omitted for clarity and to avoid redundant description. In this context, the following applies to the remainder of this description: for clarity of the drawings, if a figure contains a reference sign that is not explained in the directly relevant part of the description, reference is made to the preceding or following description section. Furthermore, for clarity, if not all features of a part are referenced in a section of a drawing, reference is made to other sections of the same drawing. Like numbers in two or more figures represent the same or similar elements.

[0029] The following examples are intended to illustrate specific embodiments of the present invention.Therefore, the specific modifications discussed below should not be interpreted as limitations on the scope of the present invention.It is clear to those skilled in the art that various equivalents, modifications and changes can be made without departing from the scope of the present invention, and therefore, it should be understood that such equivalent embodiments are included herein.Further aspects and advantages of the present invention will be apparent from the following description of specific embodiments shown in the drawings. [Brief description of the drawings]

[0030] [Figure 1] 2 is a schematic perspective view of a cap gripper according to an embodiment of the invention in the process of introducing a closure cap onto the open end of a sample vessel; FIG. [Diagram 2] 2 is a schematic side view of the cap gripper according to the embodiment shown in FIG. 1 with a closure cap firmly held therein; FIG. [Diagram 3] 3 is a schematic side view of the cap gripper according to the embodiment shown in FIGS. 1 and 2 with the closure cap released; FIG. [Figure 4] FIG. 4 is a schematic perspective view of the cap gripper according to the embodiment shown in FIGS. 1 to 3 with the closure cap released; [Figure 5a] FIG. 5 is a schematic perspective view of a gripper finger of the cap gripper according to the embodiment shown in FIGS. 1 to 4. [Figure 5b] FIG. 5 is a schematic bottom view of the gripper fingers of the cap gripper according to the embodiment shown in FIGS. 1 to 4. [Figure 5c] FIG. 5B is a schematic cross-sectional view of a gripper finger of the cap gripper according to the embodiment shown in FIGS. 1 to 4 taken along line AA in FIG. 5B. [Figure 6] 4 is a flow chart of a method for automatically closing an open end of a sample vessel with a closure cap using a cap gripper according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] FIG. 1 shows in a perspective view a freely movable cap gripper 1 for automatically closing an open end 91 of a sample vessel 9 by a closure cap 8, which grips the closure cap 8 between two opposing gripper fingers 2, which are rotationally movably connected to a cap gripper body 11. The closure cap 8 is considered to tightly close the open end 91 of the sample vessel 9 of FIG. 9, which open end 91 faces a closed or bottom end 92 of the sample vessel 9. In this embodiment, the sample vessel 9 is realized by a sample tube 9 of approximately cylindrical shape having one closed end at its bottom, i.e. the closed bottom end 92, and an open end 91 at the other end, which open end 91 is provided with a circular opening. As shown in FIG. 1, the sample tube 9 can also be provided with a printed label or an electronic tag, as is often used in laboratories to identify the contents of the sample tube 9. The gripper fingers 2 are pivotally connected to the cap gripper body 11 in such a way that they can be pivoted about a mutually common fulcrum provided by the body 11. This allows, i.e. by achieving a parallel pivoting movement of the gripper fingers 2 towards and away from each other, the gripper fingers 2 to apply, for example, the same gripping force to the closure cap 8 from both sides and to center the closure cap 8 on the longitudinal central axis CA of the cap gripper 1 (see also FIG. 2). Here, the structure of the cap gripper body 11 will not be described in more detail, since it is not the focus of the present invention and can vary in line with the usual structural composition of automated laboratory equipment.

[0032] As can be gathered from any one of Figures 1 to 4, each gripper finger consists of a gripper finger body 3 and a contact member 4, the contact member 4 is assumed to be in direct contact with the closure cap 8, while the body 3 of each gripper finger 2 transmits the general pivoting movement of each gripper finger 2 to the contact member 4. Here, each gripper finger body 3 and its contact member 4 have the same dimensions as the opposing gripper finger body 3 and its contact member 4, each gripper finger 2, i.e. its gripper finger body 3 and the respective contact member 4, form an L-shaped structure, and in the closed position of the gripper fingers 2 as shown in Figures 1 and 2, the opposing contact members 4 are arranged such that the end faces of their distal ends 21 are parallel to each other and to the central axis CA of the cap gripper 1. Also, in the closed position, the opposing gripper finger bodies 3 are also arranged parallel to each other and to the central axis CA of the cap gripper 1, and the opposing contact members 4 are arranged perpendicular to the central axis CA of the cap gripper 1.

[0033] As can be gathered from Figures 3 and 4, the closure cap 8 comprises an upper portion 81, a lower portion 82 arranged below the upper portion 81, and a shoulder portion 83 arranged between the upper portion 81 and the lower portion 82, the upper portion 81 of the closure cap 8 presenting a larger circumference than the lower portion 82 of the closure cap 8, thereby establishing the shoulder portion 83. When inserted into the open end 91 of the sample vessel 9 to be closed, the shoulder portion 83 of the closure cap 8 is pressed into the open end 91 of the sample vessel 9 until the upper edge 911 of the sample vessel 9 contacts the bottom surface of the shoulder portion 83 of the closure cap 8.

[0034] Exemplary contact members 4 of gripper fingers 2 of the cap gripper 1 of this embodiment are shown in Figures 5a to 5c, where Figure 5a is a perspective side view of the exemplary contact member 4, Figure 5b is a view from below the contact member 4, and Figure 5c is a cross-sectional view of the contact member 4 from the side taken along line AA shown in Figure 5b. Each contact member 4 constitutes the distal end 21 of the gripper finger 2 and includes different areas such as lateral gripping surfaces 41 on the inner circumference of a recess 43 at the distal end of the contact member 4, the recess 43 being meant to accommodate a portion of the upper portion 81 of the closure cap 8. The recess 43 is limited not only by the lateral gripping surfaces 41 but also by an upper push-in shelf 42. The lateral gripping surfaces 41 are used to abut / contact the outer circumference of the upper portion 81 of the closure cap 8. The upper push-in shelf 42 is used to abut / contact the flat upper or upper side surface of the closure cap 8. As the two opposing contact members 4 clamp the top 81 of the closure cap 8, the gripping force is directed towards each other and applied from two opposing sides to the periphery of the top 81 of the closure cap 8. Furthermore, the upper push ledge 42 of each contact member 4 allows a pushing or thrust force to be applied to the upper side of the closure cap 8 by each upper push ledge 42, thereby enabling the cap gripper 1 to achieve sufficient pushing force when pushing the closure cap 8 into the open end 91 of the sample container 9.

[0035] In order to achieve an improved gripping function, at least one or both lateral gripping surfaces 41 of the contact members 4 of the gripper fingers 2 are provided with a surface structure 411 in the form of, for example, circular grooves or notches of a corrugated structure, such as a plurality of juxtaposed lateral anti-slip serrations, the surface structure 411 of the lateral gripping surfaces 41 of the distal end 21 of the gripper fingers 2 matching with a respective surface structure 811 on the outer periphery of the top portion 81 of the closure cap 8, the matching or mating surface structure 811 being realised in the form of mating circular ridges or protrusions or any similar mating / interlocking structure. Thus, the retention between the contact members 4 and the closure cap 8 can be enlarged for a more secure, i.e. tighter gripping between the cap gripper 1 and the closure cap 8. Furthermore, the upper pressing ledge 42 of each gripper finger 2 provides a flat lower or bottom surface, as can be gathered for example from Fig. 5a to Fig. 5c, in order to allow a sufficient surface contact between the bottom surface of the upper pressing ledge 42 and the upper surface 812 of the upper part 81 of the closure cap 8. Thus, the pressing force as described above can be transferred in an improved manner by the contact members 4 from the gripper fingers 2 to the closure cap 8 when introducing the closure cap 8 into the open end 91 of the sample container 9. In this regard, it is pointed out that both contact members 4 when firmly gripping the closure cap 8 do not have to surround the entire upper part 81 of the closure cap 8, as can be gathered for example from Fig. 1 and Fig. 2. Here, it may be sufficient if the closure cap 8 surrounds more than half, i.e. >50%, of the outer surface of the upper part 81 of the closure cap 8 by the lateral gripping surfaces 41 and the upper pressing ledge 42 of the gripper fingers 2. That is to say, more than half of the outer surface of the upper part 81 of the closure cap 8 is accommodated in the recess 43 of the contact members 4. In this embodiment, as a specific example, the closure cap 8 can have 80 to 90% of the outer surface of the upper portion 81 of the closure cap 8 surrounded by the lateral gripping surfaces 41 and the upper push-in shelf portion 42 of the gripper fingers 2, i.e., 80 to 90% of the outer surface of the upper portion 81 of the closure cap 8 can be accommodated in the recess 43 of the contact member 4.This can ensure a tight grip between the gripper fingers 2 and the closure cap 8 and can ensure sufficient transmission of downward force from the upper push-in shelf 42 to the upper surface 811 of the closure cap 8 without the closure cap 8 tilting away from longitudinal alignment with the central axis CA. Furthermore, as can be gathered from Figures 4 and 5a to 5c, each contact member 4 is removably attached to the respective body 3 of the respective gripper finger 2, for example by a screw connection, with one or more mounting holes 44 provided in a proximal portion of each contact member 4 for receiving a respective screw and with a centering notch 45 for allowing easy attachment of each contact member 4 to the respective body 3.

[0036] In Fig. 6 a method for automatically closing the open end 91 of a sample vessel 9 by a closure cap 9 is shown. As can be gathered therefrom, the method comprises up to eight method steps S01 to S08 in the following order, steps S07 and S08 being merely optional, as explained below. More specifically, the method comprises a step S01 of providing an open sample tube 9 having an open end 91 and a closed end 92, i.e. the sample tube 9 can be held in a fixed holding device or can be held in a movable manner by a sample vessel gripper. Furthermore, the method comprises a step S02 of providing a closure cap 8. Then, the method comprises a step S03 of gripping the top part 81 of the closure cap 8 at its periphery by its surface structure 811 by a cap gripper 1 having two gripper fingers 2. Furthermore, the method comprises a step S04 of moving the closure cap 8 to the open end 91 of the sample vessel 9, which can be moved in the vicinity of the closure cap 8 if the sample vessel 9 is held by a movable sample vessel gripper. Furthermore, the method comprises a step S05 of inserting at least the lower part 82 of the closure cap 8 into the sample vessel 9, which means that the lower part 82 of the closure cap 8 is introduced, at least partially, into the open end 91 of the sample vessel 9. The method then comprises a step S06 of pushing the closure cap 8 into the open end 91 of the sample vessel 9 by means of the upper pushing shelf 42, by moving the cap gripper 1 towards the closed end 92 of the sample vessel 9 until the closure cap 8 closes the open end 91 of the sample vessel 9 in a liquid-tight manner, thereby capping or re-capping the sample vessel 9. Considering the latter, it may also be reasonable to provide a movement mechanism for the sample vessel 9 itself, so that not only the cap gripper 1 can be moved towards the sample vessel 9, but also the sample vessel 9 can be moved towards the cap gripper 1, in case of providing a movable sample vessel gripper. This may result that the closure of the sample vessel 9 may be achieved either by a movement of the cap gripper 1, a movement of the sample vessel 9, or a combined movement of both the sample vessel 9 and the cap gripper 1 towards each other.Furthermore, the method further comprises optional steps S07 and S08, namely step S07 of moving at least two gripper fingers 2 away from each other and away from the inserted closure cap 8 and step S08 of moving the cap gripper 1 away from the closed sample vessel 9. These optional steps are performed after step S06 of pushing the closure cap 8 into the open end 91 of the sample vessel 9, and as an example of an automated method, can return the cap gripper 1 to its initial position before gripping / grabbing a next closure cap 8 to be inserted into another sample vessel 9. These optional method steps thus bring the cap gripper 1 to its next starting position for performing a next automated sample vessel closure process.

[0037] The above-mentioned method steps S01 to S06, and optionally S07 and S08, may be carried out successively in a given order, and the steps S01 and S02 of providing a sample vessel 9 and a closure cap 8 may be used interchangeably.

[0038] While the present invention has been described with reference to specific embodiments thereof, it should be understood that this description is for purposes of example only, and it is therefore intended that the invention be limited only by the scope of the claims appended hereto. [Explanation of symbols]

[0039] 1 Cap Gripper 11 Cap gripper body 2 Gripper Fingers 21 Distal end of gripper finger 3 Gripper finger body 4 Gripper finger contact members 41 lateral gripping surfaces of the gripper fingers at their distal ends 411 Surface structure of the lateral gripping surface of the gripper fingers 42 upper pusher ledge at its distal end of the gripper finger 43 Recess 44 Screw mounting holes 45 Centering notch 8 Closure Cap 81 Top of Closure Cap 811 Surface structure of the upper part of the closure cap 812 Top of Closure Cap 82 Bottom of Closure Cap 821 Bottom end of closure cap 83 Closure cap shoulder 9 Sample containers / tubes 91 Open end of sample container / tube 911 Upper edge of sample container / tube 92 Closed End of Sample Container / Tube CA Cap gripper central axis S01 Method Steps S02 Method Steps S03 Method Steps S04 Method Step S05 Method Steps S06 Method Steps S07 Method Step S08 Method Step

Claims

1. A method for automatically closing the open end of a sample container (9) with a closing cap (8), (S01) The step of providing a sample container (9) that has been opened while being held, (S02) A step of providing a closing cap (8) configured to close the open end (91) of the sample container (9), (S03) A step of gripping the upper part (81) of the closing cap (8) on its outer circumference with a cap gripper (1) comprising at least two gripper fingers (2) that are movable toward each other, wherein each gripper finger (2) has a distal end (21) having a concave lateral gripping surface (41) for engaging with the outer circumference of the upper part (81) of the closing cap (8), and at least one gripper finger (2) has an upper push-in shelf portion (42) that extends at least partially over a recess (43) provided by the lateral gripping surface (41), (S04) The step of moving the closing cap (8) to the open end (91) of the sample container (9), (S05) The step of inserting at least the lower part (82) of the closing cap (8) into the sample container (9) using the cap gripper (1), (S06) The step of pushing the closing cap (8) onto the open end (91) of the sample container (9) by the upper pushing shelf (42) by moving the cap gripper (1) toward the closed end of the sample container (9) until the closing cap (8) liquid-tightly closes the open end (91) of the sample container (9), Methods that include...

2. The method according to claim 1, wherein the upper part (81) of the closing cap (8) has a surface structure (811) at least on its outer circumference, and the lateral gripping surface (41) of at least one gripper finger (2) has a surface structure (411) that conforms to the surface structure (811) of the upper part, and the step (S03) of gripping the upper part (81) of the closing cap (8) includes, between the moving step (S04) and the insertion step (S05), engagement between the surface structure (811) on the outer circumference of the upper part (81) of the closing cap (8) and the surface structure (411) of the lateral gripping surface (41).

3. The method according to claim 1, wherein the step (S04) of moving the closing cap (8) to the open end (91) of the sample container (9) includes positioning the lower end (821) of the closing cap (8) to or inside the open end (91) of the sample container (9) by the cap gripper (1).

4. The method according to claim 1, wherein the step (S05) of inserting at least the lower part (82) of the closing cap (8) into the sample container (9) before the closing cap (8) is pressed into the open end (91) of the sample container (9) includes loosening the grip of the upper part (81) of the closing cap (8) by moving the at least two gripper fingers (2) slightly apart from each other in order to disengage the lateral gripping surfaces (41) of each gripper finger (2) from the outer circumference of the upper part (81) of the closing cap (8).

5. The method according to claim 1, further comprising the steps of: moving the at least two gripper fingers (2) away from each other and away from the inserted closing cap (8) (S07); and moving the cap gripper (1) away from the closed sample container (9) (S08).

6. The method according to claim 1, wherein the step of gripping the upper part (81) of the closing cap (8) includes surrounding at least 50% of the outer surface of the upper part (81) of the closing cap (8) with the lateral gripping surfaces (41) and the upper push-in shelf portion (42) of each gripper finger (2).

7. The method according to claim 1, wherein the movement of the gripper fingers (2) toward and toward each other is achieved by the pivotal movement of the gripper fingers (2) toward a common fulcrum for centering the closing cap (8) on the longitudinal central axis (CA) of the cap gripper (1).

8. The method according to claim 1, wherein a shoulder portion (83) is provided between the upper portion (81) and the lower portion (82) of the closing cap (8), the upper portion (81) of the closing cap (8) has a larger outer circumference than the lower portion (82) of the closing cap (8), and the step (S06) of pushing the closing cap (8) onto the open end (91) of the sample container (9) includes moving the cap gripper (1) toward the closed end (92) of the sample container (9) until the shoulder portion (83) of the closing cap (8) and the upper edge (911) of the sample container (9) come into contact with each other.

9. The method according to claim 1, wherein the closing cap (8) has a substantially flat upper surface (812), the upper push-in shelf portion (42) of each gripper finger (2) provides a flat lower surface, and during the push-in step (S06), the upper push-in shelf portion (42) and the upper surface (812) of the closing cap (8) are in surface contact with each other.

10. The method according to any one of claims 1 to 9, wherein multiple method steps are performed sequentially in a predetermined order.

11. A movable cap gripper (1) for automatically closing the open end (91) of the sample container (9) with a closing cap (8), The cap gripper (1) comprises at least two gripper fingers (2) that are movable toward each other, Each gripper finger (2) has a distal end (21) having a concave lateral gripping surface (41) for engaging with the outer circumference of the upper part (81) of the closing cap (8), A cap gripper (1) having an upper push-in shelf portion (42) that at least one of the gripper fingers (2) has a distal end (21) that at least partially extends over a recess (43) provided by the lateral gripping surface (41).

12. The lateral gripping surface (41) of at least one gripper finger (2) is provided with a surface structure (411) configured to conform to the outer surface structure (811) of the closing cap (8) in order to enable a tight grip between the cap gripper (1) and the closing cap (8), and / or The cap gripper (1) according to claim 11, wherein the upper push-in shelf portion (42) of each gripper finger (2) provides a flat lower surface to enable surface contact between the upper push-in shelf portion (42) and the upper portion (81) of the closing cap (8).

13. The cap gripper (1) according to claim 11, wherein the gripper fingers (2) pivot so as to move closer to and away from each other, and the gripper fingers (2) are connected to each other around a common pivot point in order to center the closing cap (8) on the longitudinal central axis (CA) of the cap gripper (1).

14. Each gripper finger (2) is roughly L-shaped, and / or The cap gripper (1) according to claim 11, wherein each gripper finger (2) comprises a body (3) and a contact member (4) located at its distal end (21), the contact member (4) includes the lateral gripping surface (41) and the upper push-in shelf portion (42), and the contact member (4) is detachably connected to the body (3) to accommodate the cap gripper (1) for a plurality of different models of the closing cap (8).

15. A sample container closing system for automatically closing the open end (91) of a sample container (9) with a closing cap (8), comprising: a holder for the sample container (9) to be closed; a closing cap (8) for the sample container (9) to be closed; and a cap gripper (1) according to any one of claims 11 to 14.

16. The sample container closure system according to claim 15, wherein the distal end (21) of each gripper finger (2) is fitted to the model of the closure cap (8).

17. The sample container closing system according to claim 16, wherein the outer surface structure (811) of the closing cap (8) and the surface structure (411) of the lateral gripping surface (41) of each gripper finger (2) are configured to fit together.

Images