Test tube screw cap and cap holder assembly with magnets

Abstract

A cap driver (1) for a cuvette screw cap (2), a cuvette screw cap and an assembly thereof are detailed, wherein the connection between the cap driver and the screw cap is formed by a magnetic connection.

Description

Technical Field

[0001] This invention relates to improvements in test tube screw caps and cap holders in the field of automatic sealing and opening of test tube screw caps, in order to enhance their degree of automation. Background Technology

[0002] In the field of automatic sealing and opening of test tube screw caps, it has been proposed to improve the connection process between the test tube screw cap and the cap holder by setting a magnet on one side of the test tube screw cap and the cap holder, and setting an iron core or steel core or complementary ordered magnet on the other side, thereby improving the connectivity between the test tube screw cap and the cap actuator and minimizing connection wear.

[0003] When automatically sealing and opening screw caps on test tubes or bottles, where one or both the test tube and the cap are made of plastic, a recurring problem during the sealing operation is the need to control the torque applied to the screw cap to ensure that the force applied to the threads by the cap and test tube during sealing and opening does not damage the threads, while also ensuring that the cap is properly tightened after sealing.

[0004] Furthermore, since most test tubes are large quantities of non-reusable laboratory supplies, they are typically molded from low-cost plastic compositions for industrial-scale production with high tolerances and low costs.

[0005] However, standardization within the field of test tubes and in the field of standardized test tube racks used to hold standardized test tubes has significantly promoted the use of automated capping and opening devices in laboratories. Currently, the main standard for biological and microbiological test tube racks is the so-called SBS format rack, conforming to ANSI standard ANSI SLAS x-2004, where x = 1, 2, ... 6. Such SBS racks can hold, for example, 96 test tubes, using an 8×12 well array design for secure placement, but 4×6, 8×6, and other arrays are also commonly used. The advantage of automation lies in the fact that the test tube positions are predetermined by the standard, and automated equipment can rely on these predetermined positions within manufacturing tolerances.

[0006] This invention, in discussing a general solution to the problem of connecting cap actuators and test tube screw caps, particularly relates to the field of automatic capping and uncapping technology for standard screw-cap test tubes stored in standardized test tube racks (e.g., SBS format test tube racks). Therefore, in all embodiments of this invention, screw caps for test tubes conforming to the SBS standard are a particular focus of this invention.

[0007] While standardization advancements have facilitated automation, the low-cost test tubes produced are often unsuitable for repetitive automated capping and uncapping operations, as tube components are prone to failure or breakage. However, complex laboratory procedures often require multiple capping and uncapping operations to mitigate the risk of sample contamination between processing stations, making the test tubes essentially single-use items. However, screw cap components (e.g., the opposing threads on the test tube and screw cap, or the surfaces on the screw cap that are worn due to the automated capping-uncapping devices available in a particular laboratory for holding and / or ejection) are not single-use items.

[0008] In contrast, the components in the capping-opening device that contact the test tube screw cap, particularly the cap holder or screw cap ejection device (ejection plate or ejection pin), are designed for reusability. Therefore, although typically made of plastic, they are sometimes made of metals such as aluminum or steel and are manufactured to be durable. This results in a material strength mismatch between the screw cap and the cap actuator, thus causing additional wear on the screw cap. For example, prior art cap actuators rely on forming a tight connection with the screw cap through friction to rotate the screw cap during capping or opening, while holding the separated screw cap in place when the test tube is removed from the capping-opening device until it is subsequently ejected from the holder. For this purpose, screw caps conforming to various laboratory standards specify contact areas for the cap holder and the screw cap. However, it is known that soft plastic screw caps, after repeated contact with harder materials, can fail, leading to the screw cap falling off or improper reinstallation, thus causing experimental failure. A tight connection depends on the correct alignment of the screw cap and the cap actuator, which places additional demands on the structure of existing capping-opening devices.

[0009] Therefore, screw cap failure has become a significant problem in the automated sealing and opening process of test tubes. This invention aims to provide at least some solutions to overcome screw cap failure in the automated sealing or opening process of test tubes, based on the aspects and embodiments detailed herein.

[0010] Therefore, the inventors propose separating the attachment of the cap holder to the test tube screw cap (for the rotation of the screw cap) from the coupling relationship between the cap holder and the same test tube screw cap. In this disclosure, this is achieved by providing a magnetic coupling pair between the screw cap and the cap holder, as shown in the figure, in the form of a steel or iron core embedded in the screw cap and a magnet disposed in the cap holder for engaging with the aforementioned steel or iron core, thereby forming a magnetic coupling between the screw cap and the cap holder when they come into contact. Thus, the magnetic connection between the screw cap and the cap holder holds the screw cap until it is ejected, and the cap holder no longer needs to rely on a close fit with the screw cap to hold the same screw cap during capping or opening operations.

[0011] In the prior art, solutions involving magnets and test tubes have been proposed, but for purposes different from those discussed herein. For example, US5027966 discloses a storage container with a magnetic processing device, or US2011 / 0239791 discloses a magnet in a test tube cap for recovering the cap from hard-to-access locations (e.g., a test tube cap that has fallen into liquid nitrogen). These caps can be recovered by collecting the magnet from a reaction beaker using a common magnetic rod.

[0012] The solution of this invention also addresses a critical problem in the art. For example, in a test tube rack, all test tubes to be tested (e.g., in high-throughput screening, the maximum capacity of a typical SBS standard rack is 96 tubes) need to be capped or opened simultaneously. The problem of establishing a frictional connection increases at least with the number of additional test tubes, but in practice, the increase is much greater. The root cause is that the cap actuator must be designed to grip all screw caps conforming to a given standard test tube cap specification. However, the acceptable size differences between screw caps within the specification force existing cap holders to be designed to be larger than the required average size in order to grip all screw caps in the test tube rack. As the size increases, higher demands are placed on the capping-opening mechanism supporting the cap holder, requiring a sufficiently large compressive force to maintain contact between all cap holders and screw caps. This force is greater than the expected average force, resulting in existing capping-opening mechanisms being larger and more cumbersome than practical for desktop use. The problem has been solved by the solution detailed below, as the cap actuator of the present invention is now able to hold the cap even without frictional contact, thereby reducing the material requirements for the cap-opening device and enabling it to be constructed with a smaller footprint and space requirements than existing conventional cap-opening devices (which are always a scarce resource in the laboratory). Summary of the Invention

[0013] According to the present invention, the above-mentioned challenges can be overcome through the various aspects and embodiments of the invention detailed herein.

[0014] In the first aspect and embodiments of the invention (see...) Figure 1This document details a cap actuator (1) for a test tube screw cap (2), the cap actuator (1) comprising a screw cap connecting element (11) configured to connect along a common connecting axis (51) to a complementary cap actuator connecting element (21) included on the test tube screw cap (2), the screw cap connecting element (11) and the cap actuator connecting element (21) sharing at least one contact area (52a) after connection. 52b), such that rotation of the cover actuator (1) can be transmitted to rotation of the screw cap (2); the cover actuator (1) further includes at least one ferromagnetic cover actuator element (3), which is held by the cover actuator (1) to expose at least a portion (31) of the ferromagnetic cover actuator element (3) toward the connected screw cap (2), the at least a portion (31) of the ferromagnetic cover actuator element (3) being away from the cover actuator (1) in a direction parallel to the common connection axis (51).

[0015] In the second aspect (see Figure 1 This document describes in detail a test tube screw cap (2) including a cap actuator connecting element (21) configured to be connected along a common connecting axis (51) to a complementary screw cap connecting element (11), the screw cap connecting element (11) being included on a cap actuator (1) for the test tube screw cap (2), the cap actuator connecting element (21) and the screw cap connecting element (11) sharing at least one contact area (52a, 52b) after connection, such that the The rotation of the cap actuator (1) can be transmitted to the rotation of the screw cap (2); the tube screw cap (2) also includes at least one ferromagnetic screw cap element (4), which is held by the tube screw cap (2) such that at least a portion (41) of the ferromagnetic screw cap element (4) is exposed toward the connected cap actuator (1), and the at least a portion (41) of the ferromagnetic screw cap element (4) is away from the tube screw cap (2) in a direction parallel to the common connection axis (51).

[0016] In the third aspect (see Figure 1B), a component (5) is described in detail herein, the component (5) comprising a cap actuator (1) according to a first aspect and an embodiment thereof and a test tube screw cap (2) according to a second aspect and an embodiment thereof; wherein the cap actuator (1) and the test tube screw cap (2) are interconnected by complementary corresponding screw cap connecting elements (11) and cap actuator connecting elements (21), such that the cap actuator (1) and the test tube screw cap (2) share at least one contact area (52a, 52b) after connection, such that rotation of the cap actuator (1) can be transmitted to rotation of the screw cap (2); wherein the cap actuator (1) and the test tube screw cap (2) are attracted to each other by magnetic force between a ferromagnetic cap actuator element (3) and a ferromagnetic screw cap element (4); and wherein at least one of the ferromagnetic cap actuator element (3) and / or the ferromagnetic screw cap element (4) is a magnet (3, 4). Attached Figure Description

[0017] Figure 1 Exemplary embodiments of the cap-driver screw cap assembly of the present invention.

[0018] Figure 2 Exemplary embodiments of the cap-driver screw cap assembly of the present invention.

[0019] It should be understood that the embodiments shown in the figures are for illustrative purposes only and should not be construed as limiting the invention. Unless otherwise stated, the drawings should be interpreted in conjunction with the specification (e.g., cross-sectional lines, component arrangements, scale, extent, etc.) and should be considered as part of the entire written description of this disclosure. Detailed Implementation

[0020] Based on the general concepts of this disclosure, Figure 1 An exemplary cap driver (1), an exemplary screw cap (2), and an exemplary component (5) consisting of the cap driver (1) and the screw cap (2) are depicted.

[0021] In the prior art, the cap actuator (1) includes a screw cap attachment element (11), which is complementary to the cap actuator attachment element (21) in the screw cap (2). However, in the present invention, the cap actuator and the screw cap no longer need to be attached by their respective complementary attachment elements (11, 21), but only by complementary connecting elements (11, 21) to form at least one connecting region (52a, 52b), which is adapted to transmit the rotation of the cap actuator (1) to the rotation of the screw cap (2), because in the present invention, the connection and attachment of the two components (1, 2) have been decoupled, such that the attachment of the components (1, 2) is now mediated by magnetic force.

[0022] exist Figure 1In the illustrated embodiment, the screw cap attachment element (11) is a stopcock, and the cap actuator attachment element (21) is a socket for receiving the stopcock, allowing the stopcock to be received in the socket when the two components are aligned along a common connecting axis (51). The arrangement shown is for illustrative purposes only, and other attachment arrangements between the cap actuator and the screw cap are well known in the art.

[0023] However, the solution proposed herein is independent of the problem of how the cap actuator (1) and the screw cap (2) engage to form a connection, thereby enabling the rotation of the cap actuator (1) to be transmitted to the screw cap (2) during the capping or uncapping of the test tube intended for use. Therefore, this disclosure details the invention to Figure 1 The relative configuration shown is an example, in which the cap actuator (2) includes a plug (11) which is received in the opposite socket (21) when the plug (11) is aligned with the socket (21) along the common connection axis (51) (inner grip connection), the socket (21) being included in the screw cap (2). However, the invention can also employ a screw cap to form the plug and the cap actuator to form the socket (outer grip connection).

[0024] When assembled (5), the cap actuator (1) and the screw cap (2) of the present invention share at least one contact area (52), enabling rotation to be transmitted from the cap actuator (2) to the screw cap (2). In the example shown, there are two shared contact areas (52a, 52b).

[0025] In existing cap actuator and screw cap assembly technologies, the contact area is actually an overlapping area used to maintain the frictional connection between the cap actuator and the screw cap, allowing the cap actuator to resist gravity and hold the screw cap that has been removed from the test tube. In high-throughput automated processes, statistical variations in the dimensions of the screw cap and cap actuator can cause the held screw cap to frequently fall off.

[0026] To minimize this phenomenon and ensure proper connection of at least one overlapping area between the cap actuator and the screw cap, precise alignment of the cap actuator and screw cap is required when attaching the cap actuator to the screw cap. However, laboratory test tubes are rarely precisely positioned when loaded into the test tube rack. Therefore, to compensate for this lack of loading precision, additional functionality needs to be integrated into the capping / opening device (on which the cap actuator is mounted) to ensure that the cap actuator can be aligned with all test tubes in the test tube rack, regardless of the loading position of the test tubes and their attached screw caps.

[0027] One advantage of this invention is that, during assembly (5), at least one contact area (52) between the cap actuator (1) and the screw cap (2) need not be an overlapping area, but can be simply a contact area. However, the invention is equally applicable to conventional overlapping area (52) tube cap gripper arrangements in the art, and can be implemented in existing products with minimal modifications to existing equipment. Furthermore, following the teachings of this invention, the problem of material wear in at least one overlapping area is at least significantly reduced, and often completely eliminated.

[0028] Therefore, in the first aspect and embodiments of the invention (see...) Figure 1 A cap actuator (1) for a test tube screw cap (2) is described in detail herein. The cap actuator (1) includes a screw cap connecting element (11) configured to be connected along a common connecting axis (51) to a complementary cap actuator connecting element (21). The cap actuator connecting element (21) is included on the test tube screw cap (2). After connection, the screw cap connecting element (11) and the cap actuator connecting element (21) share at least one contact area (52a, 52b) such that rotation of the cap actuator (1) can be converted into rotation of the screw cap (2). The cap actuator (1) also includes at least one ferromagnetic cap actuator element (3) held by the cap actuator (1) to expose at least a portion (31) of the ferromagnetic cap actuator element (3) toward the connected screw cap (2). At least a portion (31) of the ferromagnetic cap actuator element (3) is located away from the cap actuator (1) in a direction parallel to the common connecting axis (51).

[0029] In the second aspect and its first embodiment (see Figure 1 The present invention describes in detail a test tube screw cap (2), the test tube screw cap (2) including a cap driver connection element (21) configured to be connected along a common connection axis (51) to a complementary screw cap connection element (11), the screw cap connection element (11) being included on a cap driver (1) for the test tube screw cap (2), and the cap driver connection element (21) and the screw cap connection element (11) sharing at least one contact area (52a, 52b) after connection, such that rotation of the cap driver (1) can be transmitted to rotation of the screw cap (2); the test tube screw cap (2) also includes at least one ferromagnetic screw cap element (4) held by the test tube screw cap (2) such that at least a portion (41) of the ferromagnetic screw cap element (4) is exposed toward the connected cap driver (1), the at least a portion (41) of the ferromagnetic screw cap element (4) being away from the test tube screw cap (2) in a direction parallel to the common connection axis (51).

[0030] In the third aspect and its first embodiment (see...) Figure 1 B), a component (5) is described in detail herein, comprising a cap actuator (1) according to a first aspect and an embodiment thereof and a test tube screw cap (2) according to a second aspect and an embodiment thereof; wherein the cap actuator (1) and the test tube screw cap (2) are interconnected by complementary corresponding screw cap connecting elements (11) and cap actuator connecting elements (21), such that the cap actuator (1) and the test tube screw cap (2) share at least one contact area (52a, 52b) after connection, such that rotation of the cap actuator (1) can be transmitted to rotation of the screw cap (2); wherein the cap actuator (1) and the test tube screw cap (2) are attracted to each other by magnetic force between a ferromagnetic cap actuator element (3) and a ferromagnetic screw cap element (4); and wherein at least one of the ferromagnetic cap actuator element (3) and / or the ferromagnetic screw cap element (4) is a magnet (3, 4).

[0031] In the fourth aspect and its first embodiment, a capping-opening device is described in detail, which includes at least one cap actuator (1) according to the first aspect and any embodiment thereof.

[0032] In the fifth aspect and its first embodiment, a replaceable cap actuator box is described in detail, which houses at least one cap actuator (1) according to the first aspect and any embodiment thereof, for use in conjunction with a cap-opening device according to the fourth aspect and all embodiments thereof.

[0033] In the sixth aspect and its first embodiment, a test tube for a screw cap is described in detail, which includes a test tube screw cap (2) according to the second aspect and any embodiment thereof.

[0034] In the seventh aspect and its first embodiment, a test tube rack is described in detail, comprising test tubes according to the sixth aspect and any embodiment thereof. In one embodiment of this aspect, the test tube rack is a test tube rack conforming to the SBS standard.

[0035] As discussed with respect to the components (5) of the cap actuator (1) and the screw cap (2), at least one of the ferromagnetic cap actuator element (3) and / or the ferromagnetic screw cap element (4) must be a magnet. The other ferromagnetic element (3, 4) may be any suitable magnet or magnetizable element, such as an iron core, or in some cases an iron alloy, such as magnetizable steel, or an iron alloy containing cobalt and / or nickel, to enhance the magnetizability of the magnetizable ferromagnetic element (3, 4).

[0036] Typically, in this invention, the magnet is always constituted by the cap drive element (3), because this component is reused as part of the cap driver (1), and the test tube with the screw cap (2) is a laboratory consumable, so the additional cost of using the magnet in the screw cap (2) is generally not preferred. Furthermore, since proper alignment of the magnet is very important for optimal magnetic field overlap, it is easier to align the magnet in the cap driver, for example by embedding the magnet (3) into a designated groove (12) at the tip of the cap driver (1).

[0037] Conversely, in almost all embodiments of the invention that will be put into production and sale, the ferromagnetic screw cap element (4) will be a magnetizable ferromagnetic element, such as an iron core, or in some cases an iron alloy, such as magnetizable steel, or an iron alloy containing cobalt and / or nickel, to enhance the magnetizability of the magnetizable ferromagnetic element (3, 4). In contrast, due to the reusability of the cap actuator (1), the use of, for example, relatively expensive neodymium-based magnets may be reasonable in some cases; therefore, in the context of the invention, this constitutes a preferred embodiment of the magnet (3) when it is included in the cap actuator (1).

[0038] In a preferred embodiment, the at least one magnet (3, 4) may be an electromagnet. Again, due to the reusability of the cover actuator (1), it is preferable to magnetize the ferromagnetic cover actuator element (3), but this is not necessary due to the symmetry of the connection between the cover actuator (1) and the screw cap (2).

[0039] In a particularly preferred embodiment of the invention (see...) Figure 2 The ferromagnetic screw cap element (4) is an iron ball or an iron alloy ball (e.g., magnetizable steel), which is available on the market at current prices and is suitable for inexpensive, mass-produced consumables such as laboratory test tubes. Using a spherical or ball-shaped article as the ferromagnetic screw cap element (4) has several advantages over other shapes. Notably, the spherical shape minimizes the alignment requirements of the ferromagnetic screw cap element (4) relative to the ferromagnetic cap actuator element (3), and in plastic molding technology, embedding a metal ball at a predetermined position on the surface of a thermoformed plastic article is simple and well-known.

[0040] However, when the ferromagnetic cap actuator element (3) is an annular magnet (3) aligned perpendicular to the common alignment axis (51), a spherical or ball-shaped object as a ferromagnetic screw cap element (4) has an additional advantage, because the spherical or ball-shaped ferromagnetic screw cap element (4) can now enter the open interior of the annular magnet (3), thereby improving the overlap between the magnetic field of the annular magnet (3) and the spherical or ball-shaped ferromagnetic screw cap element (4). Furthermore, when the screw cap (2) is ejected from the cap holder (1) in the cap-opening device by using an ejector pin, it is necessary to use an annular ferromagnetic cap actuator element (3), such as an annular magnet (3), which is aligned perpendicular to the common alignment axis (51), so that the ejector pin can access the screw cap (2).

[0041] Another advantage of using a ferromagnetic screw cap element (4) in a cap-opening device utilizing an ejector pin is that the ejector pin will now contact a hard metal object on the screw cap, rather than a softer plastic, which incidentally eliminates a problem in the ejector pin and cap-opening device of the prior art. In some cases, the force required to eject the screw cap from the cap actuator may cause the ejector pin to puncture the screw cap at the point of contact with the ejector pin (especially if the screw cap has been ejected several times before component failure). The present invention eliminates this problem in addition to the benefits detailed herein.

[0042] Conclusion Although the invention has been described in detail for illustrative purposes, it should be understood that such details are for that purpose only, and those skilled in the art may make changes to it by studying the drawings, the disclosure and the appended claims when practicing the claimed subject matter.

[0043] The term "comprising" as used in the claims does not exclude other elements or steps. The singular indefinite article "a" or "an" as used in the claims does not exclude a plurality. A single processor or other unit may perform the functions of several means recited in the claims. The reference numerals used in the claims should not be construed as limiting the scope.

Claims

1. A cap actuator (1) for a test tube screw cap (2), the cap actuator (1) comprising a screw cap connecting element (11) configured to connect along a common connecting axis (51) to a complementary cap actuator connecting element (21), the cap actuator connecting element (21) being included on the test tube screw cap (2), and, upon connection, the screw cap connecting element (11) and the cap actuator connecting element (21) sharing at least one contact area (52a). 52b), so that rotation of the cover actuator (1) can be transmitted to rotation of the screw cap (2); the cover actuator (1) further includes at least one ferromagnetic cover actuator element (3), the at least one ferromagnetic cover actuator element (3) being held by the cover actuator (1) to expose at least a portion (31) of the ferromagnetic cover actuator element (3) toward the connected screw cap (2), the at least a portion (31) of the ferromagnetic cover actuator element (3) being away from the cover actuator (1) in a direction parallel to the common connection axis (51).

2. The cap actuator (1) for a test tube screw cap (2) according to claim 1, wherein, The ferromagnetic cover driver element (3) is a magnet, preferably a ring magnet.

3. The cap actuator (1) for a test tube screw cap (2) according to claim 1 or 2, wherein, The ferromagnetic cover driver element (3) is an electromagnet.

4. A test tube screw cap (2) comprising a cap actuator connecting element (21) configured to connect to a complementary screw cap connecting element (11) along a common connecting axis (51), the screw cap connecting element (11) being included on a cap actuator (1) for the test tube screw cap (2), the cap actuator connecting element (21) and the screw cap connecting element (11) sharing at least one contact area (52a, 52b) after connection, such that rotation of the cap actuator (1) can be transmitted to rotation of the screw cap (2); the test tube screw cap (2) further comprising at least one ferromagnetic screw cap element (4) held by the test tube screw cap (2) such that at least a portion (41) of the ferromagnetic screw cap element (4) is exposed toward the connected cap actuator (1), the at least a portion (41) of the ferromagnetic screw cap element (4) being away from the test tube screw cap (2) in a direction parallel to the common connecting axis (51).

5. The test tube screw cap (2) according to claim 4, wherein, The ferromagnetic spiral cap element (4) is spherical or spherical.

6. A component (5) comprising a cap actuator (1) according to any one of claims 1 to 3 and a test tube screw cap (2) according to claim 4 or 5; wherein, The cap actuator (1) and the test tube screw cap (2) are connected to each other by complementary corresponding screw cap connecting elements (11) and cap actuator connecting elements (21), such that the cap actuator (1) and the test tube screw cap (2) share at least one contact area (52a, 52b) after connection, such that rotation of the cap actuator (1) is transmitted to rotation of the screw cap (2); wherein the cap actuator (1) and the test tube screw cap (2) are attached to each other by magnetic force between a ferromagnetic cap actuator element (3) and a ferromagnetic screw cap element (4); and wherein at least one of the ferromagnetic cap actuator element (3) and / or the ferromagnetic screw cap element (4) is a magnet.

7. A capping-opening device comprising at least one cap actuator (1) according to any one of claims 1 to 3.

8. A replaceable cap actuator housing, the cap actuator housing containing at least one cap actuator (1) according to any one of claims 1 to 3 for use in conjunction with the cap-opening device according to claim 7.

9. A test tube for use with a screw cap, comprising a test tube screw cap (2) according to claim 4 or 5.

10. A test tube rack comprising test tubes according to claim 9, preferably a test tube rack conforming to the SBS standard.

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