Automatic piston gripping device and pipette equipped with same

Abstract

The present invention provides an automatic piston gripping device (100) and a pipette including the same. The automatic piston gripping device includes a gripping mechanism (10), a holding shank (20), a first spring (30), and optionally a piston (40). The gripping mechanism (10) is disposed within the holding shank (20), and the first spring (30) is disposed in a sleeve-like manner on the gripping mechanism (10) and is located between the gripping mechanism (10) and the holding shank (20). The piston gripping device (100) is configured so that a piston (40) can be inserted from an end of the holding shank (20) facing a collet (11) of the gripping mechanism (10). A locking ring (12) is disposed on a head of the collet (11). A first regulating portion (21) is provided to position the locking ring (12) at the end of the holding shank (20). The piston gripping device is configured such that the collet (11) extends outward from the locking ring (12) when the locking ring (12) moves to and / or into the first restriction portion (21) to automatically grip the piston (40). The automatic piston gripping device (100) can grip the piston (40) quickly and adaptively, and can generate a sound during the process of gripping the piston that indicates the grip is about to be successful, thereby avoiding incorrect operation by the user.

Description

[Technical field]

[0001] The present invention relates to the technical field of liquid handling systems, and in particular to an automatic piston gripping device and a pipette equipped therewith. [Background technology]

[0002] In the prior art, the piston gripping mechanism is composed of a sleeve, a restrictor, a spring, and a collet. Usually, the collet, the sleeve, and the spring are used to assemble the gripping mechanism. The gripping mechanism grips the piston. The gripping mechanism of the pipette moves up and down to achieve the aspirating and dispensing of a desired amount of liquid. Many types of such liquid handling devices or products are available in scientific and industrial research laboratories for applications such as medical, pharmaceutical, and molecular biology. Summary of the Invention [Problem to be solved by the invention]

[0003] However, in order to realize the gripping of the piston through the above mechanism, the user needs to take some time to perform a preliminary operation of opening the collet before mounting the piston. Such an operation has the following problems. First, it is inconvenient and troublesome to mount the piston. Second, the piston may be damaged when mounted. Third, it is difficult to monitor whether the piston has been successfully gripped.

[0004] In consideration of these problems, the inventors of the present invention have designed an automatic piston gripping device and a pipette equipped therewith to solve the above technical problems. [Means for solving the problem]

[0005] The present invention provides an automatic piston gripping device and a pipette equipped therewith in order to eliminate the drawbacks of the prior art piston gripping mechanisms, which are inconvenient and cumbersome to operate and more likely to damage the piston during loading operations and the like.

[0006] The present invention solves the technical problems by the following technical solutions. The automatic piston gripping device includes a gripping mechanism, a holding shank, and a first spring. The gripping mechanism is arranged in the holding shank, specifically, movably arranged. The first spring is arranged in a sleeve-like manner on the gripping mechanism and is located between the gripping mechanism and the holding shank. The piston gripping device is configured so that a piston can be inserted from an end of the holding shank facing the collet of the gripping mechanism, specifically, the head of the collet. A locking ring is arranged on (the) head of the collet. The automatic piston gripping device is characterized in that a first limiting portion is provided for positioning the locking ring at the end of the holding shank, and the collet, specifically, the head of the collet, extends (moves) outward from the locking ring when the locking ring moves to and / or moves to the first limiting portion, and the piston gripping device is configured so that the piston, specifically, the piston rod, is automatically gripped.

[0007] According to one embodiment of the present invention, the gripping mechanism further comprises an adapter, a sleeve, and a second spring, the adapter being disposed within the sleeve, in particular, being movably disposed within the sleeve, the collet being mounted on an end of the adapter, and the second spring being disposed in a sleeve-like manner on the collet and located between the collet and the sleeve.

[0008] According to one embodiment of the invention, the locking ring is arranged in a sleeve-like manner on the head of the collet.

[0009] In many embodiments, the collet includes at least two jaws. In these embodiments, the head of the collet is typically defined by the at least two jaws, which are described in further detail below.

[0010] According to one embodiment of the invention, the head of the collet is a petal-like structure.

[0011] According to one embodiment, the automated piston gripping device comprises the piston, which may or may not comprise a piston rod, the piston further comprising a protrusion, in particular a protrusion of the piston rod, adapted to interact with an element such as a stop of a tip mounted or to be mounted in a pipette comprising the automated piston gripping device.

[0012] According to a more specific embodiment of the invention, the diameter of the internal gripping hole of the collet matches the diameter of a piston rod, i.e. a piston, for use with the automated piston gripping device and the pipette equipped with this device.

[0013] According to one embodiment of the present invention, a second restricting portion is provided on the inner wall of the retaining shank, a third restricting portion is provided on the outer wall of the sleeve, and two ends of the first spring abut against the second restricting portion and the third restricting portion, respectively.

[0014] Specifically, the first spring is a coil spring having just two ends, in which the first end may abut against the second restricting portion and the second end may abut against the third restricting portion.

[0015] According to one embodiment of the present invention, a fourth restricting portion is provided on the inner wall surface of the sleeve. More specifically, a fourth restricting portion is further provided. An end of the second spring abuts against the fourth restricting portion.

[0016] Specifically, the second spring is a coil spring with exactly two ends. In this case, a first end may abut against the fourth limiting portion. A second end may be arranged to move together with the collet, such as by abutting against a fifth limiting portion. The fifth limiting portion may be, for example, a limiting portion formed by the collet or the adapter, if any.

[0017] In embodiments in which the collet comprises at least two jaws, at least one of the following (i-iii) may be true:

[0018] i) the piston gripping device may be configured to allow a piston to be inserted along the longitudinal axis from an end of the retaining shank. The collet may comprise a resilient material which allows the jaws to move radially with respect to the longitudinal axis under a radial force acting on the jaws. An opening between the jaws (111) may be opened or closed by the radial movement of the jaws. Such a radial force applied to the jaws may be generated by a locking ring arranged on the head of the collet. The effect of the radial force generated by the locking ring on the jaws may vary depending on the relative movement of the head of the collet, in particular between the jaws and the locking ring.

[0019] In a more specific embodiment, the piston gripping device is configured to allow a piston to be inserted from an end of the retaining shank along the longitudinal axis and to automatically grip the piston by the head, in particular the jaws, of the collet, and the locking ring may be positionable in a first relative position of the head of the collet and the locking ring and in a second relative position of the head of the collet and the locking ring, wherein in the first relative position, the effect of the radial force generated by the locking ring on the jaws is such that the opening between the jaws is smaller than the (said) internal gripping hole of the collet, and in the second relative position, the effect of the radial force generated by the locking ring on the jaws is such that the opening between the jaws is larger than the (said) internal gripping hole of the collet.

[0020] In particular, the longitudinal axis may be the longitudinal axis of the piston gripping device, the gripping mechanism, and / or the pipette. The longitudinal axis may, and typically does, coincide with the longitudinal axis of the internal gripping bore of the collet.

[0021] The elastic material may be metal.

[0022] At least the jaws may be formed from the resilient material.

[0023] In the first relative position, the opening between the jaws may be closed, i.e. the jaws may be in contact in an area where the opening is formed.

[0024] Of course, if a piston rod is present, the first relative position cannot be assumed and / or the size of the opening between the jaws in the first relative position differs from the above-mentioned size, but in this case the piston rod is clamped between the jaws when the head of the collet, in particular the jaws and the locking ring, are in the first relative position or a relative position that can be assumed instead of the first relative position.

[0025] ii) The collet may have three jaws arranged in a circle.

[0026] iii) Each of the jaws may have an end that is an arcuate wing-type configuration.

[0027] The present invention further provides a pipette, characterized in that it comprises the automated piston gripping device according to any of the above-mentioned embodiments.

[0028] The positive and advantageous effects of the present invention are as follows: According to the automatic piston gripping device and the pipette equipped therewith, the automatic piston gripping device can grip the piston quickly and adaptively, thus solving the problem of the complicated operation of gripping the piston in the existing products or prior art.

[0029] The automatic piston gripping device can emit sounds during the process of gripping the piston to indicate successful gripping, thus avoiding incorrect operation by the user. The above-mentioned features, nature and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which like reference characters are used throughout the drawings. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic structural diagram showing a gripping mechanism of the present invention. [Diagram 2] FIG. 2 is a schematic structural diagram showing the automatic piston gripping device of the present invention. [Diagram 3] FIG. 3 is a schematic structural diagram showing gripping of a piston by the automatic piston gripping device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In order to make the above objects, features and advantages of the present invention more clear and easier to understand, embodiments of the invention are described below in detail. Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The same reference numerals used in all the accompanying drawings refer to the same or like parts whenever possible.

[0032] Furthermore, although the terms used in the present invention are selected from well-known and common terms, some of the terms mentioned in the description of the present invention may have been selected by the applicant according to the applicant's judgment, and their detailed meanings are described in the relevant paragraphs set forth in this specification.

[0033] Moreover, the invention should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0034] Fig. 1 is a schematic structural diagram showing a gripping mechanism for an automatic piston gripping device according to the present invention. Fig. 2 is a schematic structural diagram showing an automatic piston gripping device according to the present invention. Fig. 3 is a schematic structural diagram showing gripping of a piston by the automatic piston gripping device according to the present invention.

[0035] As shown in Figures 2 and 3, the present invention provides an automated piston gripping device 100. The automated piston gripping device 100 comprises a gripping mechanism 10, a retaining shank 20, a first spring 30, and optionally a piston 40. The gripping mechanism 10 is disposed within the retaining shank 20. The first spring 30 is sleeved on the gripping mechanism 10 and is located between the gripping mechanism 10 and the retaining shank 20.

[0036] The piston 40 is inserted from the end of the retaining shank 20 facing the head of the collet 11 of the gripping mechanism 10. The locking ring 12 is placed on the head of the collet 11, and the outer end of the retaining shank 20 is provided with a first restriction portion 21 for positioning the locking ring 12. After the locking portion 12 moves to the first restriction portion 21, the collet 11 extends from the locking ring 12 and automatically grips the piston 40.

[0037] Preferably, the gripping mechanism 10 further includes an adapter 13, a sleeve 14, and a second spring 15 (hereinafter also referred to as the gripping mechanism spring 15). The adapter 13 is disposed within the sleeve 14. The collet 11 is attached to an end of the adapter 13. The second spring 15 is disposed on the collet 11 in a sleeve-like manner and is located between the collet 11 and the sleeve 14.

[0038] Preferably, the locking ring 12 is sleeved in the head of the collet 11. The head of the collet 11 has a petal-like structure. The diameter of the internal gripping hole of the collet 11 matches the diameter of the piston rod of the piston 40.

[0039] Furthermore, a second restricting portion 22 is provided on the inner wall surface of the retaining shank 20. A third restricting portion 141 is provided on the outer wall surface of the sleeve 14. The two ends of the first spring 30 abut against the second restricting portion 22 and the third restricting portion 141, respectively.

[0040] Preferably, a fourth restricting portion 142 is further provided on the inner wall surface of the sleeve 14, and the end of the second spring 15 abuts against the fourth restricting portion 142. The second end of the second spring 15 is configured to move together with the collet 11. For example, the second end may be fixed to the collet 11, or if the collet 11 or the adapter 13 has a protrusion, it may abut against the protrusion, or a fifth restricting portion 143 against which the second end abuts may be provided.

[0041] More preferably, the collet 11 includes three jaws 111 arranged in a circle. Each jaw 111 has an end that is an arcuate wing-type structure.

[0042] The present invention further provides a pipette comprising the above-mentioned automatic piston gripping device.

[0043] Based on the above structural description, in the automatic piston gripping device 100 of the present invention, the gripping mechanism 10 is disposed in the holding shank 20 at the lower end of the pipette. During operation, the user first inserts the pipette into the tip box to load the tip. After the tip is loaded, the user presses down the operating handle of the pipette. Then, when a "click" sound is heard, which indicates the status of the automatic piston gripping device that ensures the correct positioning and gripping of the piston 40, the user can release the operating handle. After the piston 40 in the tip is automatically gripped by the gripping mechanism 10, the user can start the conventional liquid delivery operation.

[0044] After the operation is completed, the user presses down the operating handle to eject the tip assembly. After ejecting the tip assembly, the user releases the operating handle, and the gripping mechanism 10 returns to its initial position.

[0045] The operation of the automatic piston gripping device of the present invention will now be described.

[0046] The gripping mechanism 10 is in an initial state. The spring 15 in the gripping mechanism 10 acts as a spacer with a spring force N. The three jaws 111 on the head of the collet 11 are in a closed state, and in this state, the size of the end of the collet 11 may be smaller than the inner diameter of the locking ring 12.

[0047] A spring 15 in the gripping mechanism 10 holds the three jaws 111 on the head of the collet 11 in the locking ring 12. The locking ring 12 and the head of the collet 11 are in a first relative position, in which the three jaws 11 on the head of the collet 11 are closed, as described above. The spring 15 in the gripping mechanism 10 may be preloaded and compressed. The movement of the collet 11 in a proximal direction may be restricted, meaning from the end of the holding shank 20, in which the piston 40 is inserted, towards the main part of the pipette, which comprises, for example, the operating handle. For example, the sleeve 14 may have a stop that restricts the movement of the collet 11 in the proximal direction, or the pipette may be configured to restrict the movement of the collet 11, for example by restricting the movement of the pusher 50 in the proximal direction.

[0048] When force is applied to the gripping mechanism 10, the first spring 30 is compressed into a compressed state. As the first spring 30 is compressed, the spring force in the gripping mechanism 10 gradually increases from N. However, due to the changing influence of the acting force of the locking ring 12, the three jaws 111 on the head of the collet 11 gradually begin to open a little.

[0049] In particular, the force of the locking ring 12 on the three jaws 111 is a radial force relative to the longitudinal axis 23 of the piston gripping device 100 and gripping mechanism 10. The effect of this force can be considered to be in the range of allowing the three jaws 111 to move radially away from the longitudinal axis 23, i.e., to open, or causing the three jaws 111 to move radially towards the longitudinal axis 23, i.e., to close.

[0050] The changing effect of the force of the locking spring 12 on the three jaws 111 at the head of the collet 11 is due to the relative movement between the collet 11 and the locking ring 12 .

[0051] In detail, the compressed state of the first spring 30 is achieved by the locking ring 12 abutting against the bottom of the holding shank 20, i.e., against the first restriction portion 21. The spring force in the gripping mechanism 10 gradually increases from N as the spring 15 in the gripping mechanism 10 is compressed by the force applied to the gripping mechanism 10.

[0052] In particular, the spring constant of the first spring 30 (first spring constant) and the spring constant of the second spring 15 (second spring constant), i.e., the spring 15 in the gripping mechanism 10, may be adapted to each other such that the second spring 15 is not significantly compressed by a force applied to the gripping mechanism 10 until the first spring 30 is in a compressed state. Specifically, in an initial state, the spring force generated by the first spring 30 may be smaller than the spring force N. In addition, in a state of the gripping mechanism 10 in which the second spring 30 is in a compressed state, the spring force generated by the first spring 30 may be equal to or greater than the spring force generated by the second spring 15.

[0053] In particular, a force is applied to the gripping mechanism 10 by the user, in particular by the user pressing down on the operating handle of the pipette. During pressing down of the operating handle, the user may hold the housing of the pipette with the holding shank 20 such that relative movement occurs between the operating handle and the elements connected to it, and between the housing and the elements connected to the housing.

[0054] In particular, the force is applied to the gripping mechanism 10 by the pusher 50 acting on a proximal central region of the gripping mechanism 10. In particular, the central region does not include the proximal surface of the sleeve 14. In embodiments that include an adapter 13, the pusher 50 may act on the adapter 13, and in particular on the adapter 13 only.

[0055] As the locking ring 12 moves to the bottom of the retaining shank 20, the three jaws 111 of the collet 11 may be gradually opened up to the inner wall of the locking ring 12 and to the diameter of the internal gripping hole of the collet 11 which matches the diameter of the piston rod of the piston.

[0056] Collet 11 is released from locking ring 12 and moves to a position flush with the bottom of retaining shank 20. Locking ring 12 remains at the bottom of retaining shank 20 while collet 11 continues to move forward. In this state, the size of the end of collet 11 may be equal to the inside diameter of locking ring 12 and the size of the outside circle of the head of collet 12.

[0057] As collet 11 continues to advance and move away from the bottom of retaining shank 20, collet 11 is further released from locking ring 12. Then, under the action of the expanding elastic force of jaws 111 of collet 11, locking ring 12 moves backward and begins to move away from the bottom of retaining shank 20, during which time an impact noise is generated. In this state, the size of the end of collet 11 is equal to the outer diameter of fully opened jaws 111. Locking ring 12 and the head of collet 11 are in the second relative position in which the three jaws 111 on the head of collet 11 are fully opened, as described above.

[0058] In this state and in all previous states where the three jaws 111 are open at least to the diameter of the internal gripping hole of the collet 11 that corresponds to the diameter of the piston rod of the piston 40, the piston rod can move freely along the internal gripping hole of the collet 11 and / or can be pushed along the internal gripping hole of the collet 11. This allows the piston 40 to take a relative position to the tip that is defined by the stop of the tip if the tip is already attached to the pipette. For example, the piston 40 may move out of the gripping mechanism 10 until the protrusion 41 of the piston 40 abuts against the stop of the tip. This relative position may be the position required to start performing the delivery operation. If the tip is not yet attached to the pipette, said moving and / or pushing opportunity allows the piston 40 to be easily inserted into the automated piston gripping device.

[0059] The impact sound may be considered as an indication to the user that the automated piston gripping device 100 has reached a state that ensures correct gripping and possibly positioning of the piston 40, and that it is time to release the operating handle. The gripping of the piston 40 is triggered by the release of the operating handle and a corresponding reduction in the force applied to the gripping mechanism 10. This reduction allows the spring 15 in the gripping mechanism 10 to be released, thereby allowing the collet 11, and in particular the three jaws 111, to be retracted into the locking ring 12. This increases the effect of the force of the locking ring 12 on the collet 11, and in particular on the three jaws 111, so that the opening between the three jaws 111 is closed and thus the piston 40 is gripped.

[0060] Thereafter, if the tip is already attached to the pipette, the user can perform the dispense action in any manner appropriate for the pipette being used.

[0061] Upon completing the delivery operation, the tip, and typically also the piston 40, are ejected from their position on the pipette. Thus, a force is again applied to the gripping mechanism 10 such that the locking ring 12 moves to the bottom of the retaining shank 20 and the collet 11 moves away from the bottom of the retaining shank, to the extent that an ejection force is generated on the tip. For example, the force causing the tip to be ejected may press the projection 41 against the tip, for example against a tip stop. In this state of the collet 11, the jaws 111 are fully open so that the piston 40 is likewise ejected or can be easily removed from the automated piston gripping device.

[0062] That is, the chip and usually also the piston 40 are ejected. The collet 11 moves forward and clears the bottom of the retaining shank 20, and the end face of the piston 40 is pushed out by the collet 11, ejecting the chip and piston.

[0063] In conclusion, the automatic piston gripping device and the pipette equipped therewith can quickly and adaptively grip the piston, thereby solving the problem of complicated operations for gripping the piston in existing products or prior art.

[0064] The automatic piston gripping device can emit a sound during the process of gripping the piston to indicate a successful (or near-successful) grip, thereby avoiding incorrect operation by the user.

[0065] Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely examples, and the protection scope of the present invention is defined by the appended claims. These embodiments may be modified or changed by those skilled in the art without departing from the principles and essence of the present invention. Nevertheless, all of these modifications and changes are within the protection scope of the present invention. [Explanation of symbols]

[0066] 10 Gripping mechanism 100 Automatic piston gripping device 20 Retaining shank 30 First Spring 40 Piston 11 Colette 12 Locking ring 21 First Regulatory Division 13 Adapters 14 Sleeve 15 Second Spring 22 Second Regulatory Division 141 Third Regulatory Department 142 Fourth Regulatory Department 143 Fifth Regulatory Department 111 Jaw 50 Pusher 41 Protrusion 23 Longitudinal axis

Claims

1. Automatic piston gripping device (100), Gripping mechanism (10), Retaining shank (20) and, It is equipped with a first spring (30), The gripping mechanism (10) is located within the retaining shank (20), and the first spring (30) is arranged in a sleeve-like manner on the gripping mechanism (10) and is located between the gripping mechanism (10) and the retaining shank (20). The piston gripping device is configured such that a piston (40) can be inserted from the end of the retaining shank (20) facing the collet (11) of the gripping mechanism (10). A locking ring (12) is positioned on the head of the collet (11). An automatic piston gripping device (100) is characterized in that a first restricting portion (21) for positioning the locking ring (12) is provided at the end of the retaining shank (20), and the piston gripping device is configured such that the collet (11) extends outward from the locking ring (12) when the locking ring (12) moves to the first restricting portion (21) and / or moves to automatically grip the piston (40).

2. The gripping mechanism (10) further comprises an adapter (13), a sleeve (14), and a second spring (15). The automatic piston gripping device according to claim 1, wherein the adapter (13) is disposed within the sleeve (14), the collet (11) is mounted on the end of the adapter (13), and the second spring (15) is arranged in a sleeve-like manner on the collet (11) and is located between the collet (11) and the sleeve (14).

3. The automatic piston gripping device according to claim 2, wherein a second restricting portion (22) is provided on the inner wall of the retaining shank (20), a third restricting portion (141) is provided on the outer wall surface of the sleeve (14), and the two ends of the first spring (30) abut against the second restricting portion (22) and the third restricting portion (141), respectively.

4. The automatic piston gripping device according to claim 2, wherein a fourth restricting portion (142) is provided on the inner wall surface of the sleeve (14), and the end of the second spring (15) abuts against the fourth restricting portion (142).

5. The automatic piston gripping device according to any one of claims 1 to 4, wherein the locking ring (12) is arranged in a sleeve shape on the collet (11).

6. The head of the collet (11) has a petal-shaped structure, as described in any one of claims 1 to 4.

7. The automatic piston gripping device according to any one of claims 1 to 4, wherein the collet (11) comprises at least two jaw portions (111).

8. The automatic piston gripping device according to claim 7, wherein the collet (11) is provided with three jaws (111), and the jaws (111) are arranged in a circular shape.

9. The automatic piston gripping device according to claim 7, wherein each of the jaw portions (111) has an end portion that is an arc-shaped wing structure.

10. The piston gripping device is configured such that the piston (4) can be inserted from the end of the retaining shank (20) along the longitudinal axis (23). The collet (11) is equipped with an elastic material that receives a radial force acting on the jaw portion (111) and allows the jaw portion (111) to move radially with respect to the longitudinal axis (23). The opening between the jaw portions (111) is opened or closed by the radial movement of the jaw portions. The locking ring (12) positioned on the head of the collet (11) generates a radial force applied to the jaw portion. The effect of the radial force generated by the locking ring (12) is changed by the relative movement between the head of the collet (11) and the locking ring (12), as described in claim 7.

11. The piston gripping device is configured such that the piston (4) can be inserted from the end of the retaining shank (20), and the piston is automatically gripped by the head of the collet (11), and the locking ring (12) can be positioned in a first relative position and a second relative position. In the first relative position, the effect of the radial force generated by the locking ring (12) on the jaw portion (111) is such that the opening between the jaw portions becomes smaller than the internal gripping hole of the collet (11). The automatic piston gripping device according to claim 10, wherein, in the second relative position, the effect of the radial force generated by the locking ring (12) on the jaw portion (111) is such that the opening between the jaw portions becomes larger than the internal gripping hole of the collet (11).

12. The automatic piston gripping device according to any one of claims 1 to 4, further comprising the piston (40).

13. A pipette, characterized by comprising an automatic piston gripping device (100) as described in any one of claims 1 to 4.

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