TWI630938B - Injection pen - Google Patents

Abstract

An injection pen includes an activation mechanism and a driving mechanism. The needle-sheath coupling link and the front spring of the starting mechanism are installed in the front casing and the inner casing of the inner casing, and the front cover is disposed at the front end of the front casing and the cover needle sheath After the driving mechanism, the housing and the inner driving sleeve are connected to the front housing, the trigger tube and the key board are installed in the driving sleeve, and the spring is installed in the trigger tube after the push rod is combined, and the elastic baffle card of the driving shell is driven. The buckle drive sleeve and the push rod lock the rear spring, and the injection needle set can be installed between the activation mechanism and the drive mechanism, and the front cover is removed, and the needle sheath can press and contract into the front housing to expose the needle, and the retracted needle The sheath drives the connecting rod to push open the elastic baffle of the driving sleeve to unlock, and the released rear spring pushes the push rod to transmit the medicament to the injection needle set. After the injection, the needle sheath is pushed forward by the front spring, and the button is pulled through the connecting rod. The card is fastened in the inner casing, and the needle sheath cannot be pressed and retracted, so that the needle after use is protected from accidents caused by needle sticking.

Description

Injection pen

The invention relates to an injection pen, in particular to an injection pen which can effectively prevent people from being pinned and automatically quantitatively injecting a medicament.

At present, it is known that the injection pen is attached to the needle set containing the medicament and the needle, and after the needle cover or the rubber plug sleeved on the outer side of the needle is taken out, the needle is inserted into the skin of the human body, and then the push rod action of pressing the rear end of the injection pen is used. The movement of the piston in the needle tube is promoted by the linkage of the driving mechanism in the injection pen, so that the medicine in the needle tube is injected into the human body through the needle. After the injection, the needle is removed or the needle cover or rubber plug is re-sleeved on the outside of the needle and discarded.

Although the aforementioned known injection pen can provide a tool for subcutaneous injection, the known injection pen still has problems of insufficient safety and laborious operation, and when the injection is completed, the user must manually The needle is removed or the needle cover or rubber plug is re-sleeved on the outside of the needle and discarded. In operation, if there is care, there is still the possibility of needle sticking. Furthermore, when injecting the medicine, the user must manually press the push rod at the rear end of the injection pen to push the piston in the needle tube through the linkage of the driving mechanism in the injection pen, so that the medicine in the needle tube is injected into the human body through the needle, so There are laborious things to do.

The main object of the present invention is to provide an injection pen, which solves the problems of insufficient safety and laborious use of the existing injection pen.

In order to achieve the foregoing object, the injection pen of the present invention comprises a starting mechanism and a driving mechanism, and the driving mechanism is disposed at the rear end of the starting mechanism, wherein: the starting mechanism comprises: a front casing, wherein a forming body is formed An axially penetrating assembly space; an inner casing is installed in the assembly space of the front casing, and the inner casing comprises a front casing portion and a rear casing portion arranged in a front-rear direction, the front portion of the casing and the casing Between the rear of the casing, there is a middle partition, the middle partition has an inner hole, two first perforations and two second perforations, and the two first perforations and the second perforations are distributed on the outer periphery of the inner hole; a connecting rod is disposed in the inner casing in the axial movement of the connecting rod, the connecting rod comprises a connecting rod body, two hook portions and two trigger portions, wherein the connecting rod body forms a front and rear axial through a through hole, the two hook portions and the two trigger portions are formed on a rear end edge of the connecting rod body, the two hook portions respectively corresponding to the two first through holes of the inner sleeve, and the two trigger portions respectively pass the a second perforation; a needle sheath that is movably mounted to the front and rear In the front housing, the needle sheath is coupled to the connecting rod, and the needle sheath comprises a sheath portion and a sheath body formed on the outer side of the front portion of the sheath portion, the sheath body being located in front of the front housing and capable of being retracted a front cover; a front cover detachably disposed outside the sheath of the needle sheath and abutting against a front end of the front case; and a front spring mounted to the inner casing The front spring is located inside the two trigger portions of the connecting rod, and the front and rear ends of the front spring abut against the connecting rod and the inner sleeve respectively; the driving mechanism comprises: a rear housing, which is a a hollow housing having an opening facing forward, the rear housing being assembled to a rear end of the front housing of the starting mechanism; a driving sleeve fixed in the rear housing and extending into the front housing An axially extending receiving space is formed in the driving sleeve, and the rear end of the driving sleeve has two elastic baffles; a trigger tube is disposed in the driving sleeve, the trigger tube has an inner hole of the opening facing backward and an end plate located at the front end of the inner hole of the sleeve, wherein a through hole is formed in the end plate, and Each side of the trigger tube is provided with a side hole communicating with the inner hole of the sleeve, and the elastic baffle of the driving sleeve can be buckled in the side hole, and the trigger portion of the rear end of the connecting rod can extend into the driving sleeve The elastic baffle is biased laterally outwardly away from the side hole; the two-key plate is axially assembled in the inner side wall of the driving sleeve, and is located on the outer side of the front part of the trigger tube The front portion of the two-keyboard has two buckle portions, and the buckle portion can extend into the corresponding first through hole in the inner casing of the starting mechanism, and is engaged with the hook portion of the connecting rod, the two The rear portion of the keypad forms two elastic buckle portions having a latching portion, and the elastic buckle portion is fastened in the driving sleeve, and the key panel can be moved forward by the connecting rod to be locked and fixed to the inner sleeve Locking in the first perforation of the middle partition; a push rod is installed in the trigger tube, the push rod includes a first rod segment arranged in front and rear a second rod segment having an intermediate plate between the first rod segment and the second rod segment, the first rod segment passing through a through hole of the end plate of the trigger tube, the intermediate plate being capable of being buckled The elastic baffle of the side hole of the trigger tube is resisted; and a rear spring is disposed in the trigger tube and sleeved outside the second rod segment of the push rod, and the front and rear ends of the rear spring are respectively connected The intermediate plate and the trigger tube.

With the invention of the former injection pen, its main features are:

1. The injection pen utilizes a starter mechanism and a drive mechanism that can be separately assembled in advance, so that the injection needle can be assembled in the injection pen.

2. In the injection pen, the needle-sheath coupling link and the front spring of the starting mechanism are installed in the front casing and the inner casing of the inner casing, and the front cover is disposed at the front end of the front casing and covers the needle sheath, after the driving mechanism The housing and the inner driving sleeve are connected to the front housing of the starting mechanism, the trigger tube and the key plate are installed in the driving sleeve, and the spring is installed in the trigger tube after the push rod is combined, and the elastic baffle buckle of the driving sleeve is driven. Driving the sleeve and the push rod to lock the rear spring, thereby combining the structure, when the injection needle set is installed between the starting mechanism and the driving mechanism, before removing The cover, the needle sheath can press and contract into the front housing to expose the needle, and the needle can penetrate the human skin under the skin, and the retracted needle sheath drives the connecting rod to push open the elastic baffle of the driving sleeve to unlock, and the released rear spring can The push rod is pushed, and the piston of the injection needle group is applied with a forward thrust by the push rod, so that the injection needle group can automatically perform the quantitative delivery of the medicine.

3. After the injection pen is injected, the needle sheath can push the front spring through the connecting rod to push the reset, so that the needle sheath covers the outer side of the needle, and the key plate is buckled in the inner sleeve through the connecting rod moving forward. In turn, the needle sheath can no longer be pressed and retracted, so that the needle after use is protected from accidents caused by needle sticking.

The injection pen of the invention is installed on the front end of the front casing by the front cover and covers the outer side of the needle sheath, so as to avoid the situation that the needle sheath is accidentally pressed and contracted before the injection needle set is used, thereby ensuring the safety of use.

The injection pen of the invention can also be pressed by the needle sheath, and the needle sheath drives the connecting rod to move backward until the hook portion of the connecting rod protrudes into the first perforation of the inner casing, and the hook portion and the corresponding key plate The buckle part buckles and makes a sound, as a starting prompt; after the other key board is pulled out, the connecting rod is pulled out, and the connecting rod moves forward until the elastic block of the rear part of the key board passes through the inner sleeve. The middle partition sounds as a reminder of the end of the medicament output.

1‧‧‧Starting agency

2‧‧‧Drive mechanism

3‧‧‧Injection needle set

3A‧‧ needles

3B‧‧‧ needle tube

3C‧‧‧Piston

3D‧‧‧ rubber stopper

10‧‧‧ front housing

11‧‧‧Window Hole

12‧‧‧Snap hole

20‧‧‧ inner casing

21‧‧‧ front section of the shell

211‧‧‧Front fins

22‧‧‧After the shell

221‧‧‧ rear wing

23‧‧‧ middle partition

24‧‧‧Inside Department

25‧‧‧ 内孔

26‧‧‧First perforation

27‧‧‧Second perforation

30‧‧‧ Connecting rod

31‧‧‧ Link body

32‧‧‧K hook section

33‧‧‧ Trigger Department

34‧‧‧through holes

35‧‧‧ long hole

36‧‧‧ Snaps

40‧‧‧ needle sheath

41‧‧‧ sheath department

42‧‧‧ sheath

43‧‧‧Neutral hole

44‧‧‧Snap hole

45‧‧‧ reinforcing ribs

50‧‧‧ front cover

51‧‧‧ front cover body

52‧‧‧Connected pipe department

521‧‧‧Hook

53‧‧‧cut hole

60‧‧‧ front spring

70‧‧‧ rear housing

71‧‧‧Extension

72‧‧‧Clamping bumps

73‧‧‧Fixed holes

80‧‧‧ drive case

81‧‧‧Snap slot

82‧‧‧ Guide slot

83‧‧‧Flexible baffle

84‧‧‧Fixed bumps

90‧‧‧ trigger tube

91‧‧‧ casing bore

92‧‧‧End board

93‧‧‧With holes

94‧‧‧ side hole

A0‧‧‧Keyboard

A01‧‧‧ Clips

A02‧‧‧Flexible buckle

A03‧‧‧ card block

A1‧‧‧Put

A11‧‧‧first pole

A12‧‧‧Second section

A13‧‧‧Intermediate board

A2‧‧‧ rear spring

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partially exploded perspective view of a preferred embodiment of the injection pen of the present invention and an injection needle set.

2 is a schematic exploded view of the activation mechanism of the preferred embodiment of the injection pen of FIG. 1.

3 is an exploded perspective view of the driving mechanism in the preferred embodiment of the injection pen shown in FIG. 1.

4 is a top cross-sectional view showing the preferred embodiment of the injection pen shown in FIGS. 1 to 3 in combination with the injection needle set.

FIG. 5 is a side cross-sectional view showing the preferred embodiment of the injection pen shown in FIGS. 1 to 3 in combination with the injection needle set.

Figure 6 is a top plan view showing the preferred embodiment of the injection pen of Figure 1 in combination with the injection needle set.

Figure 7 is a top plan view showing a preferred embodiment of the injection pen of Figures 1 to 3 and Figure 6 in combination with the injection needle set.

FIG. 8 is a schematic partial cross-sectional view showing the preferred embodiment of the injection pen shown in FIGS. 1 to 3 with the front cover removed.

Figure 9 is a top plan cross-sectional view showing the preferred embodiment of the injection pen of Figures 1 to 3 after pressing the needle sheath.

Figure 10 is a top cross-sectional view showing the preferred embodiment of the injection pen of Figures 1 to 3 after pressing the needle sheath.

Figure 11 is a top plan cross-sectional view showing the preferred embodiment of the injection pen of Figures 1 to 3 after the release of the needle sheath after completion of the injection.

Figure 12 is a top cross-sectional view showing the preferred embodiment of the injection pen of Figures 1 to 3 after the needle sheath is released after the completion of the injection.

As shown in Fig. 1, a preferred embodiment of the injection pen of the present invention is disclosed for providing an injection needle set 3 therein for providing a medicament for injection. The composition of the injection pen comprises an activation mechanism 1 and a drive mechanism 2.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5, the starting mechanism comprises a front housing 10, an inner casing 20, a connecting rod 30, a needle sheath 40, a front cover 50 and a front spring 60. .

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5, a front and rear axially extending assembly space is formed in the front housing 10. In the preferred embodiment, the front side wall of the front housing 10 is provided with a through hole. The window hole 11 of the assembly space and the rear end side wall of the front housing 10 may also be provided with two engaging holes 12.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5, the inner casing 20 is installed inside the front casing 10. The front end of the inner casing 20 has a distance from the front end of the front casing 10, and the inner casing Shell 20 contains a set of shells The front section 21, the set of shell rear sections 22 and a middle partition 23, the sleeve front section 21 and the casing rear section 22 are respectively located at the front and rear sections of the inner casing 20, and the middle partition 23 is located at the front section 21 of the casing. Between the rear sections 22 of the casing, the front side of the middle partition 23 may further form an inner tube portion 24 extending forwardly to the inside of the front portion 21 of the casing, and the inner tube portion 24 forms a front and rear portion with the middle partition portion 23 An axially penetrating inner hole 25, wherein the middle partition 23 forms two first through holes 26 and two second through holes 27 with respect to the outer periphery of the inner tube portion 24, and the first through holes 26 and the second through holes 27 are staggered And the two first through holes 26 are formed to be diametrically opposed, and the two second through holes 27 are formed to be diametrically opposed.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5, in the above-mentioned inner casing 20, in the preferred embodiment, the casing front section 21 includes two diametrically opposed front fins 211, the two fronts. There is a spacing between the sides of the flap 211, the spacing between the two front flaps 211 corresponds to the window opening 11 of the front housing 10, and the rear section 22 of the casing comprises two diametrically opposite rear flaps 221, the two There is a space between the side edges of the rear flap 221, and the front flap 211 and the rear flap 221 are formed to be arranged in a front-rear direction.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5 , the connecting rod 30 is disposed in the inner casing 20 and sleeved on the outer side of the inner tube portion 24 . The connecting rod 30 includes a connecting rod body 31 . a second hook portion 32 and a second trigger portion 33. The link body 31 defines a through hole 34 extending through the front and rear axial direction. The two hook portions 32 and the two trigger portions 33 are formed behind the link body 31. The two end portions are correspondingly arranged on the two first through holes 26 of the inner casing 20, and the two trigger portions 33 respectively pass through the two second through holes 27 of the inner casing 20. An elongated hole 35 may also be formed in the link body 31 or, as in the preferred embodiment, two diametrically opposed elongated holes 35 are formed in the link body 31. The elongated hole 35 corresponds to the window hole 11 of the front case 10. The side wall of the link body 31 can also form two diametrically opposed latches 36.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5 , the needle sheath 40 is mounted in the front housing 10 and connected to the connecting rod 30 . The needle sheath 40 can move back and forth to the front housing 10 . The front end enters and exits, and the needle sheath 40 is interlocked with the link 30. The needle sheath 40 includes a sheath portion 41 and a sheath body 42. The sheath body 42 has a shape larger than that of the sheath portion 41. The sheath body 42 is formed on the outer side of the front portion of the sheath portion 41. Tube part 41 A needle-sheath intermediate hole 43 is formed in the axial direction, and the sheath body 42 is located at the front end of the link 30. The sheath portion 41 is inserted and fixed to the link body 31 of the link 30 to be interlocked. In the preferred embodiment, the side wall of the sheath portion 41 defines two fastening holes 44. The two fastening holes 44 are respectively fastened to the corresponding buckles 36 of the connecting rod body 31. The inner peripheral wall of the sheath 42 Reinforcing ribs 45 arranged at a plurality of intervals may be formed between the outer peripheral walls of the sheath portion 41.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5 , the front cover 50 is detachably sleeved on the outer side of the needle sheath 40 and abuts against the front end of the front casing 10 . The front cover 50 includes a front cover 50 . The front cover body 51 and a connecting pipe portion 52 are a cover body whose front end is a closed end and opens rearward. The connecting pipe portion 52 is formed in the front cover body 51, and the connecting pipe portion 52 is further The rear end of the front cover body 51 can be further extended. The rear end of the connecting tube portion 52 has at least all the holes 53 so that the rear end of the connecting tube portion 52 has elasticity of contraction and recovery. The front cover body 51 is sleeved on the outer side of the sheath body 42 of the needle sheath 40. The rear end of the front cover body 51 can abut against the front end of the front casing 10, and the connecting pipe portion 52 can be disposed there. The needle sheath portion 41 of the needle sheath 40 is in the needle hole intermediate hole 43. As shown in FIG. 4 and FIG. 5, in the preferred embodiment, the end of the connecting tube portion 52 can also form a hook portion 521.

As shown in FIG. 1 to FIG. 2 and FIG. 4 and FIG. 5 , the front spring 60 is mounted in the sleeve front section 21 of the inner casing 20 and sleeved on the outer side of the inner tube portion 24 . The second trigger portion 33 is located outside the front spring 60. The front and rear ends of the front spring 60 abut against the connecting rod 30 and the inner casing 20 respectively, so that the front spring 60 can be compressed and provide elastic force to the connecting rod 30.

As shown in FIG. 1 , FIG. 3 and FIG. 4 and FIG. 5 , the driving mechanism 2 is mounted on the rear end of the starting mechanism 1 , and the driving mechanism 2 includes a rear housing 70 , a driving sleeve 80 , and a trigger tube . 90. A keypad A0, a pusher A1 and a rear spring A2.

As shown in FIG. 1 , FIG. 3 and FIG. 4 and FIG. 5 , the rear housing 70 is a hollow housing having a rear end and a closed end, and the rear housing 70 can be assembled to the starting mechanism. The rear end of the front housing 10 of 1. The front end of the rear housing 70 can also form two extending pieces 71. The extending piece 71 includes a locking protrusion 72. The extending piece 71 can extend into the inner side of the rear end of the front case 10. The engaging protrusion 72 can be engaged in the corresponding engaging hole 12 at the rear end of the front case 10, so that the rear case 70 is It is fixed to the rear end of the front casing 10, and a fixing hole 73 is formed in the extending piece 71.

As shown in FIG. 1 , FIG. 3 , FIG. 4 and FIG. 5 , the driving sleeve 80 is mounted in the rear housing 70 and can protrude into the front housing 10 of the starting mechanism 1 and the inner casing. In the casing rear portion 22 of the casing 20, an axially penetrating accommodating space is formed in the driving casing 80. The inner side wall of the driving casing 80 forms two diametrically opposed fastening grooves 81 and two diametrically opposite guides. The groove 82, the fastening groove 81 and the guiding groove 82 are staggered. The rear end of the driving sleeve 80 has two diametrically opposed elastic baffles 83. The two elastic baffles 83 respectively correspond to the two guiding grooves 82. The two sides of the outer peripheral wall of the driving sleeve 80 respectively form a fixing protrusion 84. The fixing protrusions 84 are engaged in the corresponding fixing holes 73 of the rear housing 70 to fix the driving sleeve 80 in the rear housing 70. The guiding slots 82 provide the connection of the starting mechanism 1 The trigger portion 33 at the rear end of the rod 30 passes therethrough, so that the trigger portion 33 can be pushed against the elastic baffle 83 laterally outwardly.

As shown in FIG. 1 , FIG. 3 and FIG. 4 and FIG. 5 , the trigger tube 90 is mounted in the driving sleeve 80 , and the trigger tube 90 defines an inner hole 91 opening toward the rear, the trigger tube The front end of the 90 has an end plate 92. The end plate 92 defines a through hole 93. The diameter of the through hole 93 is smaller than the hole diameter of the inner hole 91 of the sleeve. A side hole 94 is defined in each of the two sides of the middle portion of the trigger tube 90, and the side hole 94 communicates with the sleeve inner hole 91.

As shown in FIG. 1 , FIG. 3 , FIG. 4 and FIG. 5 , the two-key board A0 is axially disposed on the opposite sides of the inner side wall of the driving sleeve 80 , and is located at the trigger tube 90 . The front side of the front side of the front panel has a clip portion A01. The clip portion A01 can extend into the corresponding first through hole 26 of the inner casing 20 of the starting mechanism 1 for engaging with the hook portion 32 of the connecting rod 30. An elastic button portion A02 having a card block A03 is formed on each of the two sides of the rear side of the second key plate A0. The elastic button portion A02 is fastened to the fastening groove 81 of the inner side wall of the driving sleeve 80. .

As shown in FIG. 1 , FIG. 3 and FIG. 4 and FIG. 5 , the push rod A1 includes a first rod segment A11 , a second rod segment A12 and an intermediate plate A13 , and the first rod segment A11 and the second rod segment Before and after A12 Arranged, the intermediate plate A13 is located between the first rod segment A11 and the second rod segment A12. The outer diameter of the intermediate plate A13 is smaller than the diameter of the sleeve inner hole 91 of the trigger tube 90 and larger than the through hole of the end plate 92. The aperture of the intermediate plate A13 is larger than the outer diameter of the section of the first rod segment A11 and larger than the outer diameter of the section of the second rod segment A12. The push rod A1 is installed in the trigger tube 90. The first rod segment A11 passes through the through hole 93 of the end plate 92 of the trigger tube 90. The intermediate plate A13 of the push rod A1 passes through the side of the trigger tube 90. The resilient baffle 83 of the aperture 94 abuts and the intermediate plate A13 of the pusher A1 can be constrained by the end plate of the previously located trigger tube 90.

As shown in FIG. 1 , FIG. 3 , FIG. 4 and FIG. 5 , the rear spring A2 is installed in the trigger tube 90 and sleeved on the outer side of the second rod segment A12 of the push rod A1 , and the rear end of the rear spring A2 . It is fixed in the trigger tube 90, and the front end of the rear spring A2 abuts against the intermediate plate A13.

In the use case of the injection pen of the present invention, as shown in FIG. 1, the activation mechanism 1 and the drive mechanism 2 are respectively pre-assembled, and the injection needle set 3 is installed inside the activation mechanism 1, and then The driving mechanism 2 is mounted on the rear end of the starting mechanism 1 so that the injection needle set 3 is located between the starting mechanism 1 and the driving mechanism 2, as shown in FIG. 4, FIG. 5 and FIG. 6, FIG. The needle 3B of the group 3 extends into the connecting rod 30 of the starting mechanism 1, and the needle 3A of the rubber stopper 3D is inserted into the needle sheath 40, and the rubber plug 3D is the end of the connecting tube portion 52 of the front cover 50. The hook portion 521 is snap-fitted, and the push rod A1 of the drive mechanism 2 extends into the needle tube 3B of the injection needle set 3 to abut the piston 3C.

As shown in FIG. 6 and FIG. 7, before the user wants to use the injection pen for injection, the front cover 50 is taken out from the front end of the front casing 10, and the hook portion of the end portion of the front cover 50 is connected. 521 together, the rubber stopper 3D of the injection needle set 3 is removed. At this time, as shown in FIG. 8 with FIG. 4 and FIG. 5, the needle sheath 40 is located outside the needle 3A of the injection needle set 3, so that the needle tip of the needle 3A is not exposed. .

As shown in FIG. 9 and FIG. 10 and in conjunction with FIG. 5, at the time of injection, the needle sheath 40 is pressed, the front spring 60 is compressed by the link 30 at the rear end of the needle sheath, and the needle sheath 40 can be retracted toward the front housing. 10, the needle 3A of the injection needle set 3 is exposed, and the needle tip of the needle 3A is inserted into the skin of the injection site of the human body, and by the action of the needle sheath 40 being pressed, the needle sheath 40 drives the link 30 to move backward, until The hook portion 32 of the connecting rod 30 The first through hole 26 of the inner casing 20 is extended, and the hook portion 32 is snap-fitted with the buckle portion A01 of the corresponding key plate A0 to make a sound, as a prompt for starting, and the trigger portion 33 at the rear end of the link 30 is pushed. The elastic baffle 83 of the driving sleeve 80 is detached from the side hole 94 of the trigger tube 90 and the intermediate plate A13 of the push rod A1 located in the trigger tube 90, and the original compressed spring A2 is released. By the rear spring A2, the push rod A1 is provided with a forward elastic force, and the push rod A1 applies a forward thrust to the piston 3C of the injection needle set 3, so that the injection needle set 3 injects the medicine subcutaneously to the human body through the needle 3A. During the injection, the user can view the movement of the piston 3C in the needle tube 3B through the window hole 11 of the front housing 10.

After the injection is completed, the needle is pulled out from the human body. As shown in FIG. 11 and FIG. 12, the needle sheath 40 and its connected connecting rod 30 are provided with the front spring force return by the front spring 60, and at the same time, the key plate A0 is buckled. After the connecting link 30 is pulled out, the link 30 moves forward, until the block A03 of the elastic button portion A02 of the rear portion of the key plate A0 is audible through the middle partition 23 of the inner casing 20, as a prompt for the end of the medicine output. . The elastic button portion A02 of the key sheet A0 is fastened in the first through hole 26 of the middle partition plate 23, and the block A03 protruding from the side of the elastic button portion A02 is pressed against the middle partition plate 23 to make the key The plate A0 is fixed in the intermediate partition 23 and cannot move backward, so that the needle sheath 40 can be retracted into the front casing 10 by the fixed key plate A0 and the link 30, the needle The tip of the 3A is protected by being covered in the needle sheath 40, thus allowing the user to avoid accidental needle sticking.

Claims (10)

An injection pen includes an activation mechanism and a driving mechanism, the driving mechanism is disposed at a rear end of the starting mechanism, wherein: the starting mechanism comprises: a front housing, wherein an axially through assembly space is formed; The inner casing is installed in the assembly space of the front casing, and the inner casing comprises a front portion of the casing arranged in front and rear and a rear portion of the casing, and a partition between the front portion of the casing and the rear portion of the casing a plate having an inner hole, two first perforations and two second perforations, wherein the two first perforations and the second perforations are distributed on a periphery of the inner hole; The movable ground is disposed in the inner casing, the connecting rod comprises a connecting rod body, two hook portions and two trigger portions, wherein the connecting rod body forms a through hole extending axially in front and rear, the two hook portions and The two trigger portions are formed on the rear end of the connecting rod body, and the two hook portions respectively correspond to the two first through holes of the inner sleeve, and the two trigger portions respectively pass through the two second through holes; The front housing is movably mounted in the front housing, the needle sheath connection Linked by a connecting rod, the needle sheath includes a sheath portion and a sheath body formed outside the front portion of the sheath portion, the sheath body being located in front of the front housing and retractable into the front housing; a front cover The detachable group is sleeved on the outer side of the sheath of the needle sheath and abuts against the front end of the front casing; and a front spring is disposed in the front portion of the casing of the inner casing, the front spring is located An inner side of the two trigger portions of the connecting rod abuts the connecting rod and the inner sleeve respectively; the driving mechanism comprises: a rear housing, a hollow housing with an opening facing forward, The rear housing can be assembled at the rear end of the front housing of the starting mechanism; a driving sleeve is fixed in the rear housing and can extend into the front housing, and a front and rear axial direction is formed in the driving sleeve a through hole, the rear end of the drive sleeve has two elastic baffles; a trigger tube is mounted in the drive sleeve, the trigger tube has an inner bore of the sleeve facing open rearward and is located in the sleeve An end plate of the front end of the inner hole, a through hole is formed in the end plate, and each side of the trigger tube is provided with a connection between the sleeve a side hole of the hole, the elastic baffle of the driving sleeve can be buckled in the side hole, and the trigger portion of the rear end of the connecting rod can extend into the driving sleeve to push the elastic baffle laterally outward The second key plate is disposed in the inner side wall of the driving sleeve and is located on the outer side surface of the front portion of the trigger tube, and the front portion of the two key plates has two buckle portions. The buckle portion can extend into the corresponding first through hole in the inner casing of the starting mechanism, and is engaged with the hook portion of the connecting rod, and the rear portion of the two key plate forms two elastic buckle portions having the locking block. The elastic buckle is fastened in the driving sleeve, and the key panel can be moved forward by the connecting rod to be locked and locked in the first perforation of the middle partition of the inner casing; a rod is disposed in the trigger tube, the push rod includes a first rod segment and a second rod segment arranged in front and rear, and an intermediate plate is disposed between the first rod segment and the second rod segment, the first rod a rod section passes through a through hole of the end plate of the trigger tube, the intermediate plate being capable of resisting a resilient baffle that is snapped to a side hole of the trigger tube; After the spring system is mounted within the trigger sleeve tube and the push rod provided outside the second rod segment, the front of the rear springs, respectively connected to the rear end of the intermediate tube plate and the trigger. The injection pen according to claim 1, wherein the inner side wall of the driving sleeve forms two diametrically opposite fastening grooves and two diametrically opposite guiding grooves, and the fastening grooves are staggered with the guiding grooves. The elastic baffles respectively correspond to the two guiding grooves, wherein the guiding groove provides a trigger portion of the rear end of the connecting rod, wherein the trigger portion can push the corresponding elastic baffle to laterally outwardly yaw, the two-key plate The elastic buckles on both sides of the rear section can be buckled to the fastening slots of the inner side wall of the driving sleeve. The injection pen according to claim 1, wherein the first perforation of the inner casing and the second perforation are staggered, the two first perforations are formed to be diametrically opposed, and the two second perforations are formed in a radial direction. In contrast, the front side of the middle partition of the inner casing forms an inner tube portion extending forward to the inside of the front portion of the casing, the inner hole extending into the inner tube portion, and the front spring sleeve is disposed on the inner tube portion Outside. The injection pen according to claim 2, wherein the first perforation of the inner casing and the second perforation are staggered, the two first perforations are formed to be diametrically opposed, and the second perforations are formed in a radial direction. In contrast, the front side of the middle partition of the inner casing forms an inner tube portion extending forward to the inside of the front portion of the casing, the inner hole extending into the inner tube portion, and the front spring sleeve is disposed on the inner tube portion Outside. The injection pen according to any one of claims 1 to 4, wherein the front side wall of the front casing is provided with a window hole penetrating into the assembly space, and the front portion of the casing of the inner casing comprises two diametrically opposite front a fin having a spacing between the sides of the two front flaps, a spacing between the two front flaps corresponding to a window aperture of the front housing, and a long hole formed in the connecting rod body of the connecting rod The elongated hole corresponds to the window hole of the front case. The injection pen according to any one of claims 1 to 4, wherein the rear side wall of the front casing is provided with two engaging holes, and the front end of the rear casing forms two extending pieces, and the extending pieces each include a a locking protrusion, the extending piece can extend into the inner side of the rear end of the front casing, and the engaging protrusion can be engaged in the corresponding engaging hole of the front casing, so that the rear casing is fixed to the a rear end of the front housing; a fixing hole is formed in the extending piece, and a fixing protrusion is respectively formed on two sides of the outer peripheral wall of the driving sleeve, and the fixing protrusion is engaged with the corresponding fixing body of the rear housing In the hole, the drive sleeve is fixed in the rear case. The injection pen according to claim 5, wherein the rear side wall of the front casing is provided with two engaging holes, and the front end of the rear casing forms two extending pieces, and the extending pieces each include a engaging protrusion. The extending piece can be inserted into the inner side of the rear end of the front case, and the engaging protrusion can be locked in the corresponding engaging hole of the front case, so that the rear case is fixed to the rear end of the front case; A fixing hole is formed in the extending piece, and a fixing protrusion is formed on each of the two sides of the outer peripheral wall of the driving sleeve, and the fixing protrusion is engaged with the corresponding fixing hole of the rear housing, so that the The drive housing is fixed in the rear housing. The injection pen of claim 7, wherein the side wall of the link body of the connecting rod forms two diametrically opposite latches, and the side wall of the sheath portion of the needle sheath forms two fastening holes, and the two fastening holes respectively provide The snap fastener is fastened to engage the link with the needle sheath. The injecting pen according to any one of claims 1 to 4, wherein the front cover comprises a front cover body and a connecting pipe portion, the front cover system having a front end having a closed end and an opening facing rearward, The connecting tube portion is formed in the front cover body, the connecting tube portion extends out of the rear end of the front cover body, the rear end of the connecting tube portion has at least all holes, and the end of the connecting tube portion forms a hook portion, and the front cover is front cover The body sleeve is sleeved on the outer side of the sheath body of the needle sheath, and the rear end of the front cover body can abut against the front end of the front casing, and the connecting tube portion is disposed in the sheath portion of the needle sheath. The injection pen according to claim 8, wherein the front cover comprises a front cover body and a connecting pipe portion, the front cover system has a front end which is a closed end and an opening rearward, and the connecting pipe portion is formed on the front end In the front cover body, the connecting pipe portion extends out of the rear end of the front cover body, the rear end of the connecting pipe portion has at least all holes, and the end of the connecting pipe portion forms a hook portion, and the front cover body is sleeved on the needle before the cover body The outer side of the sheath body of the sheath can abut against the front end of the front casing, and the connecting pipe portion is disposed in the sheath portion of the needle sheath.