A drive nut, a drive mechanism and an injection pen for an injection pen plunger
By designing a transmission nut in the injection pen that abuts against the side wall of the push rod channel, the problem of underutilization of the internal radial space of the injection pen is solved, resulting in a compact design that is easy to hold.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 杭州钱唐隆腾医疗技术有限公司
- Filing Date
- 2025-06-30
- Publication Date
- 2026-07-03
AI Technical Summary
The current transmission method of injection pens results in underutilization of the internal radial space, leading to a large size and difficulty in holding them.
The design employs a transmission nut, which has multiple facets on its outer circumference that abut against the side wall of the push rod channel to achieve circumferential positioning. This prevents the nut from rotating with the axis of rotation, allowing it to move only axially to push the push rod. Combined with detachable connections and snap-fit components, the transmission process is simplified.
It effectively reduces the internal radial space of the injection pen, making the pen more compact and easier to hold.
Smart Images
Figure CN224453563U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of injection pen technology, and in particular to a transmission nut, transmission mechanism and injection pen for an injection pen push rod. Background Technology
[0002] In the prior art, application number "202011391268.4" and invention title "A Control Method and Anesthesia Pusher for Anesthesia Pusher" specifically discloses that "in order to avoid the nut and the lead screw rotating synchronously during the rotation of the lead screw, the anesthesia pusher also includes a guide block connected to the nut and a guide groove opened on the inner wall of the housing. The extension direction of the guide groove coincides with the axial direction of the lead screw. The guide block cooperates with the guide groove to restrict the nut, so that the cooperation between the nut and the lead screw can convert the rotation of the lead screw into the sliding of the nut, thereby pushing the pusher to slide." Although this method can drive the pusher connected to the nut to move axially, the transmission method is relatively cumbersome, resulting in the internal radial space of the anesthesia device not being fully utilized, resulting in a large radial dimension, and thus a large overall size of the anesthesia device, making it inconvenient to hold. Utility Model Content
[0003] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide a transmission nut, transmission mechanism and injection pen for an injection pen push rod, which can effectively reduce the internal radial space dimension of the injection pen, making the overall size of the injection pen more compact and easier to hold.
[0004] The first aspect of this utility model provides a transmission nut for an injection pen push rod, comprising a nut body threadedly connected to a rotating shaft, the outer periphery of the nut body having multiple facets, each facet abutting against the side wall of the push rod channel within the injection pen holder for circumferential positioning; one end of the nut body is detachably fixedly connected to the push rod; the rotating shaft rotates, thereby driving the nut body to push the push rod to move axially.
[0005] Preferably, the nut body has a first mounting hole for connecting the rotating shaft and a second mounting hole for connecting the push rod. The diameter of the second mounting hole is larger than that of the first mounting hole. The first mounting hole and the second mounting hole communicate with each other so that the push rod can pass through the first mounting hole and the second mounting hole.
[0006] Preferably, the second mounting hole and the push rod are connected by a thread.
[0007] Preferably, the inner wall of the second mounting hole is provided with a snap-fit element, which snaps into the groove on the push rod.
[0008] Preferably, the snap-fit element is made of an elastic material.
[0009] Preferably, the end of the snap-fit component is provided with a bevel for guidance.
[0010] The second aspect of this utility model provides a transmission mechanism, including the transmission nut as described above, and further including a rotating shaft, a push rod, and a motor. The rotating shaft is tractively connected to the motor. The transmission nut is screwed onto the rotating shaft and located within the push rod channel of the injection pen. The push rod is axially slidably disposed within the push rod channel of the injection pen holder. The transmission nut is detachably connected to the end of the push rod away from the piston. The transmission nut abuts against the side wall of the push rod channel.
[0011] The third aspect of this utility model provides an injection pen, including the transmission mechanism as described above, wherein the transmission mechanism is disposed within the injection pen housing, and the transmission mechanism is connected to the injection cylinder structure at the end away from the motor.
[0012] As described above, the transmission nut, transmission mechanism, and injection pen of the injection pen push rod disclosed in this utility model have the following beneficial effects:
[0013] This invention features a transmission nut body with multiple facets. These facets abut against the sidewall of the push rod channel, achieving circumferential limiting and preventing the nut body from rotating when the rotating shaft rotates. This ensures the nut body moves only axially, thereby driving the push rod to move within the push rod channel. This invention has a compact structure, effectively reducing the internal radial space of the injection pen, making the overall size of the pen more compact and easier to hold. Attached Figure Description
[0014] Figure 1 A three-dimensional schematic diagram of the transmission nut of the injection pen push rod provided in the first embodiment of this utility model.
[0015] Figure 2 This is a half-sectional view of the transmission nut of the injection pen push rod provided in the first embodiment of the present invention.
[0016] Figure 3 This is a schematic diagram of the transmission nut of the injection pen push rod provided in the second embodiment of this utility model.
[0017] Figure 4 This is an assembly diagram of a transmission mechanism provided in one embodiment of the present invention.
[0018] Figure 5 for Figure 4 A magnified view of a portion of the image.
[0019] Explanation of reference numerals in the attached figures:
[0020] 100, Nut body; 110, First mounting hole; 120, Second mounting hole; 121, Snap-fit component; 200, Injection pen holder; 210, Push rod channel; 300, Rotating shaft; 400, Push rod; 410, Groove; 500, Motor; 600, Injection pen housing. Detailed Implementation
[0021] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0022] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.
[0023] Example 1
[0024] like Figure 1 , Figure 2 , Figure 4 and Figure 5As shown, this embodiment proposes a transmission nut embodiment for an injection pen pusher, including a nut body 100 threadedly connected to a rotating shaft 300. The outer periphery of the nut body 100 is provided with multiple facets, and each facet abuts against the side wall of the pusher channel 210 in the injection pen holder 200 for circumferential positioning. One end of the nut body 100 is detachably fixedly connected to the pusher 400. The rotating shaft 300 rotates, thereby driving the nut body 100 to push the pusher 400 to move axially. It should be noted that in this embodiment, the facet shape is preferably square, and the cross-sectional shape formed by the circumferential arrangement of the facets can be square or polygonal, such as hexagonal. The specific shape selected can be determined by those skilled in the art according to the specific working conditions, and this embodiment does not limit it in this way. Once the number of facets and the cross-sectional shape of the nut body 100 are determined, the cross-sectional shape needs to match the cross-sectional shape of the push rod channel 210 to ensure that the nut body 100 can reciprocate axially under the action of the rotating shaft. During this process, each facet on the outer periphery of the nut body 100 needs to fit against the side wall of the push rod channel 210 to prevent the nut body 100 from rotating with the rotating shaft 300 when the rotating shaft 300 rotates, which would make it difficult for the nut body 100 to move axially and push the push rod 400 to reciprocate axially.
[0025] To reduce the radial space dimension of the injection pen, this embodiment places the nut body 100 within the push rod channel 210 of the injection pen holder 200. By circumferentially limiting the nut body 100, it ensures that it can axially push the push rod 400 to move under the drive of the rotating shaft 300. At the same time, it avoids setting auxiliary guide devices on the outside of the injection pen holder 200, thereby making full use of the radial space and significantly reducing the volume of the injection pen in the radial direction, making it easier for the operator to hold.
[0026] Furthermore, such as Figure 2 and Figure 5 As shown, the nut body 100 has a first mounting hole 110 for connecting the rotating shaft 300 and a second mounting hole 120 for connecting the push rod. The diameter of the second mounting hole 120 is larger than that of the first mounting hole 110. The first mounting hole 110 and the second mounting hole 120 communicate with each other so that the rotating shaft 300 can pass through the first mounting hole 110 and the second mounting hole 120. The first mounting hole 110 has a thread, and the nut body 100 is screwed onto the rotating shaft 300. With circumferential limitation, this allows the rotating shaft 300 to rotate, enabling the nut body 100 to move axially. It should be noted that the diameter of the second mounting hole 120 is larger than that of the first mounting hole 110 to facilitate the connection between the nut body 100 and the push rod 400. In this embodiment, the second mounting hole 120 has a thread, and the push rod 400 has a thread at the end furthest from the piston, allowing the nut body 100 and the push rod 400 to be connected by a thread, facilitating future maintenance and replacement.
[0027] Example 2
[0028] This embodiment is basically the same as Embodiment 1, except that, as Figure 3 As shown, the second mounting hole 120 and the first mounting hole 110 are stepped holes. The first mounting hole 110 has a thread for screwing onto the rotating shaft 300. A snap-fit element 121 is provided on the inner wall of the second mounting hole 120, which snaps into the groove 410 on the push rod. Driven by the rotating shaft 300, the nut body 100 pushes the push rod 400 axially through the snap-fit element 121.
[0029] For easy disassembly, the snap-fit component 121 may be made of an elastic material.
[0030] In order to enable the snap-fit 121 to snap smoothly into the groove 410, a bevel is provided at the end of the snap-fit 121 for guidance. After snap-fit, the bevel remains in the groove 410 and has the function of a barb to prevent the snap-fit 121 from disengaging from the push rod 400 when the nut body 100 moves axially back and forth.
[0031] The second aspect of this utility model proposes a transmission mechanism, such as... Figure 4 As shown, the device includes the transmission nut in any of the above embodiments, as well as a rotating shaft 300, a push rod 400, and a motor 500. The rotating shaft 300 is driveably connected to the motor 500. The transmission nut is screwed onto the rotating shaft 300 and located within the injection pen push rod channel 210. The push rod 400 is axially slidably disposed within the push rod channel 210 of the injection pen holder. The transmission nut is detachably connected to the end of the push rod away from the piston, and abuts against the side wall of the push rod channel 210. The motor 500 and the rotating shaft 300 are connected by a coupling. A bearing is provided at the end near the coupling. The transmission nut at the end away from the coupling, in addition to pushing the push rod axially under the push of the rotating shaft 300, also acts as a bearing to ensure the overall transmission stability of the transmission mechanism.
[0032] In use, the rotating shaft 300 is driven to rotate by the motor 500, which in turn causes the transmission nut to move axially and push the push rod to move within the push rod channel 210.
[0033] The third aspect of this utility model provides an injection pen, including a transmission mechanism disposed within the injection pen housing 600. The transmission mechanism is connected to the injection cylinder structure at its end furthest from the motor. In use, the motor 500 drives the rotating shaft 300 to rotate, thereby causing the transmission nut to move axially, pushing the push rod 400 to move within the push rod channel 210, thus realizing the injection action of the injection pen.
[0034] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A drive nut for an injection pen plunger rod, characterized by The device includes a nut body (100) threaded onto a rotating shaft (300). The outer periphery of the nut body (100) has multiple facets, and each facet abuts against the side wall of the push rod channel (210) in the injection pen holder (200) for circumferential positioning. One end of the nut body (100) is detachably fixedly connected to the push rod (400). The rotating shaft (300) rotates, thereby driving the nut body (100) to push the push rod (400) to move axially.
2. Drive nut for an injection pen plunger rod according to claim 1, characterized in that The nut body (100) is provided with a first mounting hole (110) for connecting the rotating shaft (300) and a second mounting hole (120) for connecting the push rod. The diameter of the second mounting hole (120) is larger than that of the first mounting hole (110). The first mounting hole (110) and the second mounting hole (120) are connected so that the rotating shaft (300) can pass through the first mounting hole (110) and the second mounting hole (120).
3. The transmission nut of the injection pen plunger according to claim 2, characterized in that, The second mounting hole (120) is threadedly connected to the push rod (400).
4. The drive nut of a pen-type syringe plunger rod of claim 2, wherein, The inner wall of the second mounting hole (120) is provided with a snap-fit member (121), which snaps into the groove (410) on the push rod.
5. Drive nut for an injection pen plunger rod according to claim 4, characterized in that The snap-fit component (121) is made of an elastic material.
6. Drive nut for an injection pen plunger rod according to claim 5, characterized in that The end of the snap-fit (121) is provided with a bevel for guidance.
7. A transmission mechanism, characterised in that, The device includes the transmission nut as described in any one of claims 1 to 6, and further includes a rotating shaft (300), a push rod (400), and a motor (500). The rotating shaft (300) is tractively connected to the motor (500). The transmission nut is screwed onto the rotating shaft (300) and located within the injection pen push rod channel (210). The push rod (400) is axially slidably disposed within the push rod channel (210) of the injection pen holder. The transmission nut is detachably connected to the end of the push rod away from the piston. The transmission nut abuts against the side wall of the push rod channel (210).
8. An injection pen characterized in that Includes the transmission mechanism as described in claim 7, wherein the transmission mechanism is disposed within the injection pen housing (600), and the transmission mechanism is connected to the injection cylinder structure at the end away from the motor.