Disposable injection pen

Abstract

The present invention discloses a disposable injection pen, which includes a pen cap, a syringe sleeve, a button and a pen body tube. Inside the pen body tube, there are provided a screw rod, a positioner, a first spring, a movable anti-backlash tooth, a transmission rack, a pen body tube, a threaded guide sleeve, a dose knob, a clutch and a rotating shaft. The threaded guide sleeve is connected to one end of the pen body tube, and the button is connected to one end of the rotating shaft, with a second spring provided at the connection therebetween. The other end of the rotating shaft is inserted into the interior of the clutch, and the clutch is inserted into the interior of the dose knob. In the present invention, the injection pressure for the patient to operate is lower because the pressure of the thrust is mainly controlled by the size of the spring, which is easy to design and produce. In the traditional structure, the pressure of the main thrust is mainly controlled by the performance of the plastic and the tooth profile of the size, and it is rather troublesome to design and adjust the force, and it is not conducive to production due to the influence of the injection molding process.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a disposable injection pen. Background Art

[0002] Currently, for some special patients in clinical practice, such as diabetic patients, hepatitis patients, etc., they need to frequently inject insulin, interferon, growth hormone, vaccines, etc. by themselves in different occasions, and the accuracy requirements for the injection dose are particularly high. When ordinary patients use the old-fashioned disposable syringes, it is neither convenient nor can they effectively achieve accurate medication; in addition, the existing syringes that can achieve accuracy have disadvantages such as high price, complex structure, and inconvenient use. Summary of the Invention

[0003] The purpose of the present invention is to solve the disadvantages existing in the prior art, and a disposable injection pen is proposed. The injection pressure for patients to operate is lower because the pressure of the thrust is mainly controlled by the size of the spring, which is easy to design and produce; in the traditional structure, the pressure of the main thrust is mainly controlled by the performance of the plastic and the tooth shape of the size, and it is more troublesome to design and adjust the force, and it is not conducive to production due to the influence of the injection molding process.

[0004] In order to achieve the above purpose, the present invention adopts the following technical scheme:

[0005] A disposable injection pen, comprising a pen cap, a syringe sleeve, a button, and a pen body tube. Inside the pen body tube, there are provided a screw, a locator, a first spring, a movable anti-backlash tooth, a transmission rack, a pen body tube, a thread guide sleeve, a dose knob, a clutch, and a rotating shaft. The thread guide sleeve is connected to one end of the pen body tube. The button is connected to one end of the rotating shaft, and a second spring is provided at the connection. The other end of the rotating shaft is inserted into the inside of the clutch. The clutch is inserted into the inside of the dose knob. The dose knob is inserted into the inside of the pen body tube, and the thread guide sleeve is provided at the connection of the two. The transmission rack is hollow, and a fixed anti-backlash tooth that can move freely on the transmission rack is provided at one end, and the other end passes through the clutch and is inserted into the inside of the rotating shaft. One end of the screw is threadedly connected inside the transmission rack, and a movable anti-backlash tooth that cooperates with the fixed anti-backlash tooth is sleeved on the screw. The other end of the screw passes through the locator and is connected to a piston. A second spring is sleeved between the locator and the movable anti-backlash tooth where the screw is located.

[0006] Preferably, the movable anti-backlash tooth can move freely along the axial direction of the screw.

[0007] Preferably, the piston is exposed outside the pen body tube for injection propulsion.

[0008] Preferably, a locking ring is provided at the connection between the clutch and the dose knob.

[0009] Preferably, the syringe sleeve is a cylindrical shape with openings at both ends. At one end opening, there are protruding blocks on the inner surface, and the protruding blocks are snap-fitted into the locator.

[0010] Preferably, the pitch of the screw is 0.5 - 2 mm, and the thread length is 5 - 40 mm.

[0011] The present invention has the following beneficial effects:

[0012] 1. The injection pressure for the patient to operate is lower because the pressure of the thrust is mainly controlled by the size of the spring, which is easy to design and produce.

[0013] 2. In the traditional structure, the pressure of the main thrust is mainly controlled by the performance of the plastic and the tooth shape of the size. It is rather troublesome to design and adjust the strength, and it is not conducive to production due to the influence of the injection molding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is an exploded structural schematic diagram of the disposable injection pen proposed by the present invention;

[0015] In the figure: 1 piston, 2 screw, 3 locator, 4 second spring, 5 movable anti-backlash tooth, 6 fixed anti-backlash tooth, 7 transmission rack, 8 pen body tube, 9 thread guide sleeve, 10 dose knob, 11 locking ring, 12 clutch, 13 rotating shaft, 14 first spring, 15 button, 16 syringe sleeve, 17 pen cap. DETAILED DESCRIPTION OF THE INVENTION

[0016] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0017] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0019] Referring to Figure 1 , a disposable injection pen, comprising a pen cap 17, a syringe sleeve 16, a button 15 and a pen body tube 8. Inside the pen body tube 8, there are provided a screw 2, a locator 3, a first spring 4, a movable anti-backlash tooth 5, a transmission rack 7, a pen body tube 8, a threaded guide sleeve 9, a dose knob 10, a clutch 12 and a rotating shaft 13. The threaded guide sleeve 9 is connected to one end of the pen body tube 8. The button 15 is connected to one end of the rotating shaft 13, and a second spring 14 is provided at the connection therebetween. The other end of the rotating shaft 13 is inserted into the interior of the clutch 12. The clutch 12 is inserted into the interior of the dose knob 10, and a locking ring 11 is provided at the connection between the clutch 12 and the dose knob 10. The dose knob 10 is inserted into the interior of the pen body tube 8, and the threaded guide sleeve 9 is provided at their connection.

[0020] The transmission rack 7 is hollow, and a fixed anti-backlash tooth 6 that can move freely on the transmission rack 7 is provided at one end thereof. The other end passes through the clutch 12 and is inserted into the interior of the rotating shaft 13. One end of the screw 2 is threadedly connected inside the transmission rack 7, and a movable anti-backlash tooth 5 that cooperates with the fixed anti-backlash tooth 6 is sleeved on the screw 2. The movable anti-backlash tooth 5 can move freely along the axial direction of the screw 2. The other end of the screw 2 passes through the locator 3 and is connected to a piston 1. The piston 1 is exposed outside the pen body tube 8 and is used for injection propulsion. A second spring 4 is sleeved between the locator 3 and the movable anti-backlash tooth 5 on the screw 2.

[0021] The syringe sleeve 16 is a cylindrical shape with openings at both ends. At the opening at one end and on the inner surface, there are provided protruding blocks, and the protruding blocks are snap-fitted into the locator 3.

[0022] In the present invention, when the dose knob 10 is rotated to the limit position, at this time, the clutch 12 is under less pressure due to the large stroke of the first spring 14. The transmission rack 7 and the movable anti-backlash tooth 5 are in a static state due to the reverse tooth resistance of the fixed anti-backlash tooth 6. Since the dose knob 10 rotates upward and comes into rotational contact with the clutch 12 gear, a clicking sound is generated, and the locking ring 11 rises as the dose knob 11 rotates upward (the rising distance is the size of the knob screwed out upward).

[0023] The transmission rack 7 and the movable anti-backlash tooth 5 are blocked by the meshing of the fixed anti-backlash tooth 6, and the acting forces cancel each other out, so there is no movement.

[0024] When the button 15 is pressed for injection, since the force of the button 15 acts downward, the second spring 4 is compressed and the stroke becomes shorter. The clutch 12 is under the pressure of the first spring 14 and the gears coincide. At this time, the locking ring 11 moves together with the dose knob 10 and the clutch 12 in the same downward rotation direction. When the transmission rack 7 moves downward under the action of the dose knob 10, at the same time, the fixed anti-return tooth 6 and the movable anti-return tooth 5 act, and the friction between the gears generates sound, thereby driving the screw 2 to advance forward. The following actions are repeated until the locking ring 11 and the clutch 12 are locked and the dose knob 10 cannot be screwed out upward, indicating the maximum dose and the injection is completed.

[0025] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. Disposable injection pen, characterized in that, it includes a pen cap (17), a syringe sleeve (16), a button (15) and a pen body tube (8). Inside the pen body tube (8), there are provided a screw rod (2), a positioner (3), a first spring (14), a movable anti-backlash tooth (5), a transmission rack (7), a threaded guide sleeve (9), a dose knob (10), a clutch (12) and a rotating shaft (13). The threaded guide sleeve (9) is connected to one end of the pen body tube (8). The button (15) is connected to one end of the rotating shaft (13). A first spring (14) is provided at the connection between the button (15) and the rotating shaft (13). The other end of the rotating shaft (13) is inserted into the inside of the clutch (12). The clutch (12) is inserted into the inside of the dose knob (10). The dose knob (10) is inserted into the inside of the pen body tube (8), and the threaded guide sleeve (9) is provided at the connection between the dose knob (10) and the pen body tube (8). The transmission rack (7) is hollow. At one end, there is a fixed anti-backlash tooth (6) that can move freely on the transmission rack (7). The other end passes through the clutch (12) and is inserted into the inside of the rotating shaft (13). One end of the screw rod (2) is threadedly connected inside the transmission rack (7), and a movable anti-backlash tooth (5) that cooperates with the fixed anti-backlash tooth (6) is sleeved on the screw rod (2). The other end of the screw rod (2) passes through the positioner (3) and is connected to a piston (1). A second spring (4) is sleeved on the part of the screw rod (2) between the positioner (3) and the movable anti-backlash tooth (5); the movable anti-backlash tooth (5) can move freely along the axial direction of the screw rod (2); the piston (1) is exposed outside the pen body tube (8) for injection propulsion; a locking ring (11) is provided at the connection between the clutch (12) and the dose knob (10); the syringe sleeve (16) is a cylindrical shape with both ends open. At the open end of one end, there are protruding blocks on the inner surface, and the protruding blocks are snap-fitted into the positioner (3); the pitch of the screw rod (2) is 0.5 - 2 mm, and the thread length is 5 - 40 mm.

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