Injection pump nut opening and closing device

Abstract

The embodiment of the utility model discloses an injection pump nut opening and closing device which comprises an injection pump sliding seat, a half nut and a lead screw, the half nut is vertically arranged in the injection pump sliding seat, and the lead screw vertically penetrates through the injection pump sliding seat. The meshing position of the half nut and the lead screw is located in the geometric center of the injection pump sliding seat. According to the scheme, the effective contact part of the screw rod and the half nut is positioned in the center of the injection pump sliding seat, so that the structure stress is symmetrical relative to the structure, and the operation is more stable.

Description

Technical Field

[0001] This application relates to the field of syringe pump technology, and in particular to a syringe pump nut opening and closing device. Background Technology

[0002] In laboratory equipment, laboratory syringe pumps are mainly used for the precise transfer of small volumes of liquid fluid. The specific process involves using a special syringe as a container, clamping the syringe onto the syringe pump, with the syringe tail contacting the syringe pump slide. The movement of the syringe pump slide is used to achieve the precise movement of the syringe piston, thereby achieving the purpose of precise fluid transfer within the syringe.

[0003] In current technology, a lead screw and nut are often used as the drive mechanism for the syringe pump slide. Due to the repeated disassembly and reassembly of syringes in laboratory experiments, in practical applications, the nut in this drive structure often includes an opening and closing mechanism. This mechanism involves cutting the nut in half and attaching a mechanism to one half to enable opening and closing. When the syringe pump slide needs to push the syringe, this mechanism closes, the lead screw rotates, and the syringe pump slide moves forward or backward. When loading or unloading the syringe, the half-nut opens and engages with the lead screw, allowing the syringe pump slide to move freely back and forth, facilitating syringe loading and unloading. Summary of the Invention

[0004] This specification provides an embodiment of an injection pump nut opening and closing device, including: an injection pump slide, a half nut, and a lead screw, wherein the half nut is vertically disposed inside the injection pump slide, the lead screw passes vertically through the injection pump slide, and the engagement position of the half nut and the lead screw is located at the geometric center of the injection pump slide.

[0005] Optionally, a position locking device may be provided at the contact point between the injection pump slide and the half nut.

[0006] Optionally, the position locking device may include a limiting body, and a positioning groove is provided inside the injection pump slide. The limiting body passes through the half nut and cooperates with the positioning groove to limit the position of the half nut. When the half nut is engaged with the lead screw, the limiting body is embedded in the positioning groove, and the position of the half nut is locked.

[0007] Optionally, the position locking device may further include a positioning sleeve, which is fixed inside the syringe pump slide and has a positioning groove.

[0008] Optionally, the position locking device may further include a handle disposed inside the syringe pump slide. The handle moves up and down inside the syringe pump slide to allow the limiting body to be inserted into and removed from the positioning groove.

[0009] Optionally, the position locking device may further include: a handle compression spring, the lower end face of which presses against the upper end face of the bottom protrusion of the handle, the upper end face of which is in contact with the upper end face inside the half nut, and the handle compression spring is in a compressed state.

[0010] Optionally, the injection pump nut opening and closing device may further include: a half-nut compression spring and a limiting plate, the limiting plate being fitted into the upper end of the injection pump slide, and the half-nut compression spring being disposed between the upper end surface of the outer periphery of the half-nut and the lower end surface of the limiting plate.

[0011] Optionally, the handle passes sequentially through the upper part of the half nut, the handle compression spring, the half nut compression spring, and the limiting plate, with its top protruding from the upper end of the injection pump slide.

[0012] Optionally, a wrench may be provided at the upper end of the injection pump slide, the wrench being hinged to the half nut, and the wrench being used to disengage the half nut from the lead screw.

[0013] Optionally, the wrench may be hinged to the top of the handle.

[0014] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0015] This design places the effective contact point between the lead screw and the half nut in the center of the injection pump slide, making the force on the structure symmetrical and the operation more stable.

[0016] The addition of a half-nut position locking device in this solution makes the engagement between the half-nut and the lead screw more stable, effectively improving the service life of the half-nut and reducing the frequency of maintenance.

[0017] The wrench in this design is ergonomically designed for greater comfort and a better user experience. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 A three-dimensional structural diagram of the experimental injection pump chamber using the injection pump nut opening and closing device provided in this scheme;

[0020] Figure 2 This is an assembly drawing of the syringe pump slide and lead screw;

[0021] Figure 3 for Figure 2A partial cross-sectional view taken along the vertical plane of the syringe pump slide;

[0022] Figure 4 A cross-sectional assembly diagram showing the limiting body disengaging from the positioning groove and the half nut being unlocked after the handle presses down on the handle spring.

[0023] Figure 5 A cross-sectional assembly diagram showing the structure in which the handle moves the half nut upward, compresses the half nut and presses the spring, and disengages the half nut from the lead screw.

[0024] Figure 6 A three-dimensional schematic diagram of the half-nut disengaging from the lead screw;

[0025] Figure 7a This is a three-dimensional structural diagram of a half-nut;

[0026] Figure 7b This is a schematic diagram of the vertical cross-sectional structure of a half nut;

[0027] Figure 8a A schematic diagram of the three-dimensional structure of the handle;

[0028] Figure 8b A plan view of the handle;

[0029] Reference numerals: 1. Injection pump; 2. Syringe; 3. Injection pump slide; 4. Lead screw; 6. Half nut; 7. Positioning groove; 8. Limiting body; 9. Positioning sleeve; 10. Handle; 11. Handle compression spring; 12. Half nut compression spring; 13. Limiting plate; 14. Wrench; 15. Connecting pin; 16. Slot; 17. Rotating pin; 18. Positioning surface. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In existing technologies, a half-nut is often horizontally arranged on the slide of the injection pump. When closed, the teeth of the half-nut are engaged and pressed tightly with the teeth of the lead screw by the clamping spring force. However, this structure has two problems. First, the force on the half-nut is different from that of a fully enclosed nut; the force is biased to one side. Horizontally setting the half-nut will cause the force to deviate from the structural center of the slide, resulting in uneven loading during slide movement and fluctuations in liquid flow rate at the output. Second, the engagement between the half-nut and the lead screw is inherently unbalanced in force. Although the spring force helps to counteract this, the structural asymmetry will still lead to abnormal wear, reduce the life of the half-nut, and increase the frequency of equipment maintenance.

[0032] The above are some common problems in the daily application of existing laboratory syringe pumps. Solving these problems will help to promote the use and application of laboratory syringe pumps and increase their stability and reliability in experiments.

[0033] To achieve the above functions, this application adopts the following technical solution:

[0034] A half-nut is installed vertically in the middle of the slide of the laboratory syringe pump. The half-nut engages with the lead screw at the geometric center of the slide. That is, the thread of the half-nut is located at the lower end of the inside of the syringe pump slide, and its force direction is also at its geometric center. This ensures the smoothness of the syringe pump's thrust on the syringe and maintains the smoothness of liquid transmission.

[0035] In addition, a position locking device is installed at the contact point between the injection pump slide and the half nut. This device can ensure that the half nut is locked when it reaches the position of engaging with the lead screw, thereby counteracting abnormal wear caused by off-center load and greatly increasing the service life of the half nut.

[0036] The improvement is that a wrench is also installed at the upper end of the half-nut opening and closing device. The wrench is hinged to the half-nut, and by turning the wrench, the half-nut can be easily disengaged from the screw, thus optimizing the operation of the injection pump.

[0037] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0038] The overall structure of the syringe pump is as follows Figure 1 As shown, a proprietary syringe 2 is attached to the syringe pump 1, and the tail end of the syringe 2 contacts the syringe pump slide 3.

[0039] like Figure 2 As shown, Figure 1 Other components of the injection pump are hidden, with only the injection pump slide 3 and lead screw 4 remaining. The rotation of the lead screw 4 drives the injection pump slide 3 to move back and forth on the injection pump 1.

[0040] like Figure 3As shown, the syringe pump slide 3 is vertically cut open, revealing that the lead screw 4 engages with the half nut 6, which is positioned at the vertical center of the syringe pump slide 3. This design ensures that the effective contact area between the lead screw and the half nut is located at the center of the syringe pump slide, making the structural stress symmetrical and resulting in smoother operation.

[0041] In addition, this solution also adds a half nut position locking device, which includes: a limiting body 8, a limiting body 8 is provided on the half nut 6, and a positioning groove 7 is provided on the injection pump slide 3. The limiting body 8 passes through the half nut 6 and cooperates with the positioning groove 7 to limit the position of the half nut 6. When the half nut 6 is engaged with the lead screw 4, the limiting body 8 is embedded in the positioning groove 7 to lock the half nut 6.

[0042] Furthermore, a positioning sleeve 9 can be set, which is fixed inside the injection pump slide 3. A positioning groove 7 is provided on the positioning sleeve 9, which is more conducive to processing.

[0043] To facilitate the insertion and removal of the limiting body 8 from the positioning groove 7, a handle 10 can be provided. The handle 10 is located inside the syringe pump slide 3. By moving the handle 10 up and down inside the syringe pump slide 3, the limiting body 8 can be inserted into and removed from the positioning groove 7. Specifically, the lower end of the handle 10 is provided with a positioning surface 18. When the handle 10 is in the position as shown in the image, the limiting body 8 can be inserted into and removed from the positioning groove 7. Figure 3 Position, its positioning surface 18 pushes the limiting body 8 into the positioning groove 7, at which time the half nut 6 is in a locked state.

[0044] The added half-nut position locking device (i.e. positioning device) makes the engagement between the half-nut and the lead screw more stable, effectively improving the service life of the half-nut and reducing the frequency of maintenance.

[0045] The limiting body 8 can be a sphere, a cylinder, or other irregular shape, with the fundamental principle being that it can cooperate with the positioning groove 7 to complete locking and unlocking.

[0046] It should be noted that there can be one, two or more limiters 8. In order to maintain stable position locking, it is best to set three or more.

[0047] At the junction of the handle 10 and the handle compression spring 11, the lower end face of the handle compression spring 11 presses against the upper end face of the bottom protrusion of the handle 10, and the upper end face of the handle compression spring 11 is in contact with the upper end face inside the half nut 6. The handle compression spring 11 is in a compressed state and can provide downward pressure to assist in completing the locking action.

[0048] In addition, this design also includes a half-nut compression spring 12 and a limiting plate 13. The limiting plate 13 is fitted into the upper end of the syringe pump slide 3, and the half-nut compression spring 12 is positioned between the upper outer surface of the half-nut 6 and the lower outer surface of the limiting plate 13. The half-nut compression spring 12 provides assistance in pressing the half-nut 6 downwards and also helps eliminate positioning gaps.

[0049] The handle 10 can be a stepped shaft that passes through the upper part of the half nut 6, the handle pressure spring 11, the half nut pressure spring 12, and the limiting plate 13, with its top protruding from the upper end of the injection pump slide 3. The limiting plate 13 has a hole in the middle.

[0050] like Figure 4 As shown, when the handle 10 presses against the handle pressure spring 11, the limit body 8 disengages from the positioning groove 7, and the half nut 6 is released from locking.

[0051] like Figure 5 As shown, when the handle 10 moves upward, it drives the half-nut 6 upward, compressing the half-nut lower spring 12, and the half-nut 6 disengages from the lead screw 4. A three-dimensional assembly diagram of this state can be found in [reference needed]. Figure 6 , Figure 6 An upward-angled view is provided to demonstrate the position of half nut 6 disengaged from the screw.

[0052] like Figure 5 and 6 As shown, a wrench 14 can also be installed at the upper end of the handle 10, and the wrench 14 is hinged to the handle 10 via a connecting pin 15 (e.g., Figure 5 As shown, the wrench is ergonomically designed to better suit human operating habits.

[0053] Furthermore, the wrench 14 is hinged to the injection pump slide 3 via a rotating pin 17, allowing the wrench 14 to rotate around the rotating pin 17, thereby linking the handle 10 and pulling the half nut 6. The wrench 14 in this design makes the overall structure more stable.

[0054] In some embodiments, such as Figure 7a and Figure 7b As shown, the half-nut 6 is a hollow cylindrical structure with a stepped hole in the middle, a semi-circular internal thread at the bottom, and two through holes on the middle side wall. The handle 10 passes through the hollow cylindrical structure and engages with the stepped hole. The semi-circular internal thread is used for engagement with the lead screw. The limiting body 8 passes through the through hole of the half-nut 6 and engages with the positioning groove 7, which can limit the position of the half-nut 6. When the half-nut 6 engages with the lead screw 4, the limiting body 8 embeds into the positioning groove 7, locking the half-nut 6.

[0055] like Figure 8a and Figure 8bAs shown, the handle 10 is a stepped shaft with a through hole on the top side. The connecting pin 15 passes through the through hole to hinge the wrench 14 to the handle 10.

[0056] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the device that includes said element.

[0057] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A nut opening and closing device for an injection pump, characterized in that, include: The syringe pump includes a slide, a half-nut, and a lead screw. The half-nut is vertically disposed inside the syringe pump slide, and the lead screw passes vertically through the syringe pump slide. The engagement position of the half-nut and the lead screw is located at the geometric center of the syringe pump slide. A position locking device is provided at the contact point between the syringe pump slide and the half-nut.

2. The syringe pump nut opening and closing device as described in claim 1, characterized in that, The position locking device includes a limiting body. A positioning groove is provided inside the injection pump slide. The limiting body passes through the half nut and cooperates with the positioning groove to limit the position of the half nut. When the half nut is engaged with the lead screw, the limiting body is embedded in the positioning groove, and the position of the half nut is locked.

3. The syringe pump nut opening and closing device as described in claim 2, characterized in that, The position locking device also includes a positioning sleeve, which is fixed inside the injection pump slide and has a positioning groove.

4. The syringe pump nut opening and closing device as described in claim 2, characterized in that, The position locking device also includes a handle, which is disposed inside the syringe pump slide. The handle moves up and down inside the syringe pump slide to allow the limiting body to be inserted into and removed from the positioning groove.

5. The syringe pump nut opening and closing device as described in claim 4, characterized in that, The position locking device further includes: a handle compression spring, the lower end face of which presses against the upper end face of the bottom protrusion of the handle, the upper end face of which is in contact with the upper end face inside the half nut, and the handle compression spring is in a compressed state.

6. The syringe pump nut opening and closing device as described in claim 4, characterized in that, The injection pump nut opening and closing device further includes: a half-nut compression spring and a limiting plate. The limiting plate is fitted into the upper end of the injection pump slide, and the half-nut compression spring is disposed between the upper end surface of the outer periphery of the half-nut and the lower end surface of the limiting plate.

7. The syringe pump nut opening and closing device as described in claim 6, characterized in that, The handle passes sequentially through the upper part of the half nut, the handle pressure spring, the half nut pressure spring, and the limiting plate, with its top protruding from the upper end of the injection pump slide.

8. The syringe pump nut opening and closing device as described in claim 4, characterized in that, A wrench is provided at the upper end of the injection pump slide, the wrench is hinged to the half nut, and the wrench is used to disengage the half nut from the lead screw.

9. The syringe pump nut opening and closing device as described in claim 8, characterized in that, The wrench is hinged to the top of the handle.

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