Abstract:
The present utility model provides an electrically powered needle-free injector ( 100 ), comprising: a needle-free injector body ( 120 ); and a needle-free injection end ( 130 ) extending distally from the needle-free injector body ( 120 ) for medicine administration, the needle-free injector body ( 120 ) comprises: a housing ( 3 ), an inside of which is divided into a pressurized injection chamber ( 123 ) and a motor chamber ( 124 ); a pressurized injection assembly ( 170 ) disposed within the pressurized injection chamber ( 123 ); a needle-free injector locking mechanism ( 180 ) at least partially disposed within the pressurized injection chamber; and a motor assembly ( 190 ) disposed within the motor chamber ( 124 ). The present utility model has a beneficial effect that it may provide a power source for the needle-free injector to electrically take medicine and inject by a built-in motor; it works reliably, is used conveniently, and has a small size.

Description:
FIELD OF THE INVENTION 
       [0001]    The present utility model relates to the technical field of medicine and medical equipment, and more particularly, to an electrically-powered needle-free injector. 
       BACKGROUND OF THE INVENTION 
       [0002]    With the development of the pharmaceutical industry, a number of biological preparations have emerged, characterized by a small injection amount and repeated injection. A needle injector causes needle phobia and acupuncture pain, which, however, can be effectively avoided by a needle-free injector. 
         [0003]    Current commercially available needle-free injectors usually pressurize liquid medicine through an external power source, such that the liquid medicine penetrates the skin through very fine mircopores at high pressure and high speed into the body. In other words, the liquid medicine can straightly penetrate the human or animal skin into the body without a needle. Meanwhile, the needle-free injector may also make the injected medicine more disperse, which facilitates absorption of the medicine and reduces invasion of subcutaneous tissues, thereby avoiding formation of induration. 
         [0004]    However, since needle-free injectors have not been around for quite a while, they still have many drawbacks. For example, the current civilian needle-free injectors are basically pressurized manually, which are very inconvenient for users. The electric needle-free injectors used in large and medium-sized hospitals have a longer length, and thus a larger size, which are also very inconvenient to be operated. 
         [0005]    In actual production and life, there is an urgent need for a needle-free injector hick can be easily operated and has a simple structure. 
       SUMMARY OF THE INVENTION 
       [0006]    An objective of the utility model is to provide an electrically-powered needle-free injector which may take medicine and inject electrically through a built-in motor, works reliably, is operated conveniently, and has a small size. 
         [0007]    According to the utility model, there is provided an electrically-powered needle-free injector, comprising: a needle-free injector body; and a needle-free injection end extending distally from the needle-free injector body for medicine administration. The needle-free injector body comprises: a housing, an inside of which is divided into a pressurized injection chamber and a motor chamber; a pressurized injection assembly disposed within the pressurized injection chamber; a needle-free injector locking mechanism at least partially disposed within the pressurized injection chamber; and a motor assembly disposed within the motor chamber. 
         [0008]    According to a preferred embodiment, a longitudinal axis of the pressurized injection assembly is parallel to a longitudinal axis of the motor assembly. 
         [0009]    According to a preferred embodiment, the pressurized injection assembly comprises: a push rod, a pressure spring sleeved on the push rod, and a compression body at least partially encircling the push rod and the pressure spring. 
         [0010]    According to a preferred embodiment; a push rod boss is provided at a distal side of the push rod, and a step shoulder is provided inside of the compression body, a distal end of the pressure spring abuts against the push rod boss and a proximal end of the pressure spring abuts against the step shoulder, such that when the compression body is driven by the motor assembly, the pressure spring can be pressurized. 
         [0011]    According to a preferred embodiment, the needle-free injector locking mechanism can lock the compression body and the push rod together via a locking ball passing through a wall of the compression body and entering into a groove at a proximal end of the push rod, thereby locking the pressure spring in a pressurized state. 
         [0012]    According to a preferred embodiment, the needle-free injector locking mechanism comprises a hollow button, an inner end of the button having a flat step and a button groove disposed proximal to the flat step; in a locked state, the flat step abuts against the locking ball that passes through the wall of the compression body and enters into the groove at the proximal end of the push rod to prevent detachment of the locking ball; to unlock for injection, the button is depressed to move the flat step to a distal side, and the locking ball is pushed to enter into the button groove to allow unlocking of the push rod from the compression body. 
         [0013]    According to a preferred embodiment, the compression body comprises a compression body main body of a substantially sleeve-shaped structure and a force-transmitting portion extending upward from the compression body main body, the force-transmitting portion being formed with a central hole for receiving the motor assembly. 
         [0014]    According to a preferred embodiment, the compression body main body comprises an inner wall thickened portion to form: (a) the step shoulder for abutting against the proximal end of the pressure spring; and (b) a deep groove longitudinally extending from the proximal end of the compression body main body, for receiving a portion of the needle-free injector locking mechanism. 
         [0015]    [001.] According to a preferred embodiment, a partitioning wall extending proximally from an inner side of a distal wall of the housing and an upper-side wall of the compression body main body together divide the inside of the housing into the pressurized injection chamber and the motor chamber. 
         [0016]    According to a preferred embodiment, the partitioning wall supports, at above, a motor of the motor assembly. 
         [0017]    According to a preferred embodiment, the motor assembly comprises: a motor, a motor shaft projecting from the motor, and a screw rod connected to the motor shaft, the screw rod extending along an axis of the motor assembly and passing through the central hole of the force-transmitting portion. 
         [0018]    According to a preferred embodiment, the needle-free injector locking mechanism comprises: a hollow button inserted into the deep groove at the proximal end of the compression body main body, an inner end of the button having a flat step and a button groove disposed proximal to the flat step; a lock column whose proximal end is disposed inside the button and contacts with an inner wall of the button; a button spring disposed inside the button and positioned proximal to the lock column; a small hole in a wall of the compression body; a locking ball; and a groove of the push rod. 
         [0019]    In the present utility model, a longitudinal axis of the pressurized injection assembly is parallel to a longitudinal axis of the motor assembly, such that compared with a co-axial structure, a length of the needle-free injector may be shortened. The utility model has a built-in motor and may accurately control start, stop, clockwise rotation and counterclockwise rotation of the motor. 
         [0020]    In the present utility model, a partitioning wall extending proximally from an inner side of a distal wall of the housing and an upper-side wall of the compression body main body together divide the inside of the housing into the pressurized injection chamber and the motor chamber, which makes the structure more compact and simpler. 
         [0021]    The present utility model has a beneficial effect that it may provide a power source for the needle-free injector to electrically take medicine and inject by a built-in motor; it works reliably, is used conveniently, and has a small size. 
     
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         [0022]      FIG. 1  is a longitudinal sectional view of a needle-free injector according to preferred embodiment of the present utility model, where the needle-free injector is in a released state. 
           [0023]      FIG. 2  is a schematic diagram of the needle-free injector of  FIG. 1  in a pressurized state. 
           [0024]      FIG. 3  is a schematic diagram of the needle-free injector of  FIG. 1  in a state of taking medicine and adjusting dosage. 
           [0025]      FIG. 4  is a schematic diagram of an appearance of a needle-free injector according to a preferred embodiment of the present utility model. 
           [0026]      FIG. 5  is a locally enlarged view of a rear part of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    According to spirit of the present utility model, there exist a plurality of embodiments to achieve objectives of the present utility model. Hereinafter, a structure, configuration, and working principle of the needle-free injector of the present utility model will be explained according to preferred embodiments shown in the drawings. With reference to the preferred embodiments, those skilled in the art may envisage other embodiments that can achieve the objectives of the present utility model. 
         [0028]    In the context of the present disclosure, the term “distal side” refers to a side of the needle-free injector during use proximal to a patient&#39;s skin; the term “proximal side” refers to a side of the needle-free injector during use distal from a patient&#39;s skin; the terms “above,” “below,” “left,” and “right” are relative to the figure plane shown in the drawings, the terms “longitudinal” and “radial” are relative to the longitudinal axis of the needle-free injector. Besides, like parts are indicated by the same reference numerals. 
         [0029]      FIG. 4  is a schematic diagram of an appearance of a needle-free injector  100  according to a preferred embodiment of the present utility model. The needle-free injector  100  according to the present utility model comprises: a needle-free injector body  120 ; and a needle-free injection end  130  extending distally from the needle-free injector body  120  for medicine administration. Referring to  FIGS. 1-3 , the needle-free injector body  120  comprises: a housing  3 , an inside of which is divided into a pressurized injection chamber  123  and a motor chamber  124 ; a pressurized injection assembly  170  disposed within the pressurized injection chamber  123 ; a needle-free injector locking mechanism  180  at least partially disposed within the pressurized injection chamber  123 ; and a motor assembly  190  disposed within the motor chamber  124 . 
         [0030]    According to a preferred embodiment of the present utility model, a distal end lower side of the housing  3  is provided with a first hole  121  available for the needle-free injection end  130  to extend distally from the needle-free injector body  120  (see  FIGS. 1-3 ), and a proximal end lower side of the housing  3  is provided with a second hole  122  available for the needle-free injector locking mechanism  180  to extend proximally out of the housing  3  (see  FIGS. 1-3 ). In addition, an exterior side of the housing  3  is also provided with control means  200 . In a preferred embodiment, the control means  200  may comprise at least one control button, e.g., a switching key  19 , etc., so as to separately or collectively control release, pressurization, and taking-medicine of the needle-free injector  100 . 
         [0031]      FIG. 1  is a longitudinal sectional view of the needle-free injector  100  according to a preferred embodiment of the present utility model, where the needle-free injector  100  is in a released state. As shown in  FIG. 1 , an inside of the housing  3  of the needle-free injector  100  is divided into a pressurized injection chamber  123  and a motor chamber  124 . The housing  3  may be split or integral. The pressurized injection assembly  170  has a pressurized injection assembly longitudinal axis X-X through centers of the first hole  121  and second hole  122 , and a motor assembly longitudinal axis X 1 -X 1  of the motor assembly  190  driving the needle-free injector  100 . As illustrated in  FIG. 1 , the pressurized injection assembly longitudinal axis X-X and the motor assembly longitudinal axis X 1 -X 1  are parallel to each other. 
         [0032]    As shown in the drawings, in general, the electrically-powered needle-free injector  100  according to the present utility model comprises: a piston  1 , a medicine tube wall  2 , the housing  3 , a motor  5 , a screw rod  8 , a compression body  9 , a steel ball  10 , a button  11 , a button spring  12 , a lock column  13 , a push rod  14 , and a pressure spring  15 , the compression body being of a tubular structure, a screw nut  16  extending perpendicularly at an outside wall of the compression body  9 , the screw rod  8  being socketed on the screw nut, one end of the screw rod being connected to a motor shaft  6 ; the other end of the screw rod being connected to one end of the housing  3 ; an axis of the push rod  14  (i.e., the pressurized injection assembly longitudinal axis X-X) is parallel to an axis of the motor shaft  6  (i.e., the motor assembly longitudinal axis X 1 -X 1 ). 
         [0033]    Specifically, as shown in  FIG. 1 , the needle-free injection end  130  comprises a medicine tube wall  2  extending distally from the first hole  121  of the housing  3  and the piston  1  disposed within the medicine tube wall  2 . Particularly, the medicine tube wall  2  is of a substantially cylindrical shape and has a substantially closed conical distal end and an open diameter-diminished proximal end. The conical distal end has a micropore  131  through a conical apex, for squirting medicine liquid during use. The diameter-diminished portion of the diameter-diminished proximal end may be just received within the first hole  121 , and a step shoulder formed by the diminished diameter abuts against an external side of a distal wall of the housing  3 . Of course, those skilled in the art may understand that a connection between the needle-free injection end  130  and the housing  3  is not limited thereto; besides, the diameter-diminished portion and the first hole  121  may be joined in any known manner, including, but not limited to, adhesion, screwed connection, etc. 
         [0034]    As mentioned above, the needle-free injector  100  also comprises: the pressurized injection assembly  170  disposed within the pressurized injection chamber  123 ; the needle-free injector locking mechanism  180  at least partially disposed within the pressurized injection chamber  123 ; and the motor assembly  190  disposed within the motor chamber  124 . Particularly, the pressurized injection assembly  170  comprises: the push rod  14 , the pressure spring  15  sleeved on the push rod  14 , and the compression body  9  at least partially encircling the push rod  14  and the pressure spring  15 . Particularly, the pressure spring  15  can be pressurized, while the needle-free injector locking mechanism  180  can lock it in a pressurized state and unlock it in the need of injection. Specifically, the push rod  14  extends along the pressurized injection assembly longitudinal axis X-X and has a push distal end  141  that may extend into the medicine tube wall  2  and a proximal end portion  142 . A push rod boss  18  is formed between the push distal end  141  and the proximal portion  142 ; when the push rod  14  completes medicine injection, the push rod boss  18  may press against a distal wall inner side of the housing  3 . A proximal end  143  of the push rod  14  is provided with a groove  17  that is arranged peripherally around the push rod  14 . The pressure spring  15  is sleeved on the proximal portion  142  of the push rod  14 , while a distal end of the pressure spring abuts against the push rod boss  18 . 
         [0035]    Besides, still referring to  FIGS. 1-3 , the compression body  9  comprises a compression body main body  91  of a substantially sleeve-shaped structure and a force-transmitting portion extending upward from the compression body main body  91 , i.e., a screw nut  16 . The force-transmitting portion is substantially positioned at a proximal portion of the sleeve-shaped structure of the compression body main body  91 , and an inner wall thickened portion  93  is formed because an inner wall of the proximal portion of the sleeve-shaped structure corresponding to the force-transmitting portion is inwardly thickened; a step shoulder  94  is formed at an intersection between the inner wall thickened portion  93  and the remaining portion of the sleeve-shaped structure. The inner wall thickened portion  93  has an inner diameter substantially identical to an outer diameter of the push rod  14 . A proximal portion of the inner wall thickened portion  93  is formed with a deep groove  95  extending longitudinally from the proximal end for receiving the needle-free injector locking mechanism  180 . Moreover, the proximal portion of the compression body main body  91  may extend out from the second hole  122 . Besides, the force-transmitting portion is formed with a central hole  92  through which the screw rod  8  passes. Preferably, a flange  96  is provided at an outer side of the distal end of the compression body main body  91 . As shown in  FIGS. 1-3 and 5 , the deep groove  95  causes that the proximal portion of the compression body main body  91  has a first inner side wall  98  and a second outer side wall  99 , and small holes  101  are formed at corresponding portions of the first inner side wall  98  (e.g., the upper and lower positions shown in the figure). 
         [0036]    After the assembly, the proximal portion of the compression body main body  91  extends out from the second hole  122 ; the flange  96  at its lower side is supported on a lower wall of the housing  3  and at its upper side contacts with a segment of a partitioning wall  31  extending proximally from an inner side of the distal wall of the housing  3 ; the push rod  14  and the pressure spring  15  sleeved on the push rod  14  are disposed within the compression body main body  91 , and the other end of the pressure spring  15  abuts against the step shoulder  94 . In this way, the partitioning wall  31  and the wall of the compression body main body  91  form the pressurized injection chamber  124 . 
         [0037]    As illustrated in  FIG. 1 , the partitioning wall  31  supports, at above, the motor  5 , and the screw rod  8  connected to the motor shaft  6  of the motor  5  extends along the motor assembly axis X 1 -X 1  and passes through the hole  92  of the power-transmitting portion, i.e., the screw nut  16 . A rotary shaft  4  at the other end of the screw rod is rotatably connected to the housing  3  via a bearing  7 . 
         [0038]    In other words, the piston  1  positioned within the medicine tube wall  2  plays a role of sealing the medicine during taking medicine and injection. Connected to the piston  1  is the push rod  14  outside of which is sleeved the pressure spring  15 ; a groove  17  disposed at a rear end side wall of the push rod  14  may receive the steel ball  10  in a locked state (which will be discussed infra). A front end of the pressure spring  15  contacts the push rod boss  18  of the push rod  14 , and a rear end of the pressure spring  15  contacts with the compression body  9  inner step. The compression body  9  may be axially displaced to compress and move the pressure spring  15 . The screw nut  16  connected to the compression body  9  has an inner screw that is screwed with the screw rod  8 . Rotation of the screw rod  8  will lead to axial displacement of the screw nut  16 . The screw rod  8  is connected to the motor  5 , such that when the motor  5  rotates, the screw rod  8  will rotate together. 
         [0039]      FIG. 5  is a locally enlarged view of a rear part of  FIG. 3 , emphatically showing the needle-free injector locking mechanism  180 . The needle-free injector locking mechanism  180  locks the push rod  14  with the compression body  9  by virtue of a locking ball engaged with holes or grooves in walls of different members, e.g., steel ball  10 , such that the compression spring  15  is held in a pressurized state. 
         [0040]    More specifically, as shown in  FIG. 5 , the needle-free injector locking mechanism  180  comprises: steel balls  10  that may freely pass through small holes  101  in the first inner side wall  98  of the compression body main body  91 , the groove  17  of the push rod, a groove  11 B and a locking flat step  11 C formed in the side wall of the button  11 . 
         [0041]    Referring to  FIG. 5 , the hollow button  11  has a longitudinal cross section of a substantially U-shape and a step shoulder  11 A formed on its outside wall, such that after the button is inserted into the deep groove  95  of the proximal end of the compression body main body  91  and moved to the most proximal side position, the step shoulder  11 A abuts against an inner flange  97  formed by an outer wall of the proximal end of the compression body main body  91 , thereby preventing the button  11  from being disengaged from the needle-free injector. Besides, the groove  11 B is formed at an inner wall distal portion of the button  11 . A longitudinal cross-section of the lock column  13  is of a substantially T shape, the maximum diameter of the proximal end of the T-shape is consistent with an inner diameter of the button  11 . After being mounted, the proximal end of the lock column  13  is disposed within the button  11  and contacts with the inner wall of the button  11 ; a button spring  12  is disposed within the button  11  and positioned proximal to the lock column  13 , one end of the button spring abutting against the proximal end of the lock column  13 , the other end abutting against the proximal wall of the button  11 ; a smaller-diameter cylindrical portion of the lock column  13  extends inside the proximal side portion of the sleeve-shaped structure of the compression body main body  91 . 
         [0042]    When the injector needs to work, by touching a switching key  19  of control means  200 , the motor  5  will rotate to cause rotation of the screw rod  8 , while rotation of the screw rod  8  will thread drive the compression body  9  to move to the left. Because the distal end of the pressure spring  15  abuts against the push boss  18  and the proximal end of the pressure spring  15  abuts against the step shoulder  94  of the compression body  9 , as the compression body  9  moves to the left, the pressure spring  15  will be pressurized. Meanwhile, a right end of the push rod  14  approaches to the lock column  13  and pushes the lock column  13  to compress the button spring  12 . When the compression body moves to a certain position, the steel ball  10  may enter into the groove  17  at the right end of the push rod  14 , and the button  11  will be ejected out under the action of the button spring  12 . The flat step at the end portion of the button  11  presses the steel hall  10  into the groove at the right end of the push rod  14 , thereby locking the push rod  14  with the compression body  9 ; in this way, the pressure spring  15  is locked in the pressurized state, as shown in  FIG. 2 . 
         [0043]    Afterwards, the injector enters into the process of taking medicine and regulating dosage ( FIG. 3  shows a state of taking medicine and regulating dosage). When the motor  5  rotates reversely, the compression body  9  will move to the right side to drive the push rod (at this time, the push rod  14  is locked together with the compression body  9 ), the piston  1 , the compression spring  15 , and the lock column  13  to move together to the right side. During the movement process, a negative pressure will be formed inside the medicine tube wall  2 , and then the medicine will enter into the medicine tube wall  2  through the small hole at the front end of the medicine tube wall  2 . Meanwhile, an interstice is formed between the step shoulder at the left of the push rod  14  and the housing  3 . The size of the interstice is decided by the injection dosage. 
         [0044]    When injecting the medicine, the button  11  is pressed down to be moved to the left; the steel ball, pushed by the push rod  14 , enters into the groove of the button  11 . The push rod  14  is not bound by steel ball, and the push rod  14  and the compression body  9  will not be locked any longer; the pressure spring  15  in the pressurized state will act; the push rod  14 , under the action of the pressure spring  15 , moves promptly to the left. The elasticity of the pressure spring  15  acts on the medicine in the medicine tube wall  2  under the action of the push rod  14  and the piston  1 , such that the medicine is rapidly squirted out and injected into the body. Then, one working process is completed, and the needle-free injector returns to the state of  FIG. 1 . 
         [0045]    What have been mentioned above are preferred embodiments of the present utility model and the technical principle as applied. To those skilled in the art, without departing from the spirit and scope of the present utility model, any obvious changes such as equivalent transformations and simple substitutions based on the technical solutions of the present utility model fall within the protection scope of the utility model.