RU2355430C2 - Injection device - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: injection device has external case, inside which there is a cylinder for preserving definite medication volume; needle on one cylinder end; piston which can move in axial direction inside cylinder; internal case between external case and cylinder and piston; and source of energy, interacting with said internal case. Needle and cylinder are made such that at least part of needle can move in axial direction into said external case and out of it, but normally is completely displaced into said case. Internal case can be moved by energy source between three positions. First position, in which internal case has one or several radially elastic ears, interacting with cylinder in such way that during use piston and cylinder can move in axial direction in order to move at least part of said needle out of external case. Second position, in which external case has one or several radially elastic ears, which interact with piston but do not interact with cylinder in such way that during use said piston can move in axial direction into said cylinder in order to push medication through needle. Third position, in which said one or several radially elastic ears on internal case do not interact neither with piston nor with cylinder in such way that during use piston and cylinder can be pulled inside, in order to pull needle into external case.

EFFECT: simple and economically efficient means for delivery of medication through removable needle, in case of necessity able to deliver medication to depth exceeding needle length due to moving force created by energy source.

30 cl, 27 dwg

Description

The present invention relates to the field of injection devices for administering a liquid drug, for example insulin or growth hormone.

One type of injection device is known as a mini or microneedle device. These devices contain an injection system under high pressure (“forced” injection) and have a needle that is shorter than needles in known needle systems. The needle is usually hidden, which is advantageous both from the point of view of preventing damage due to sticking of the needle, and from the point of view of reducing psychological trauma to patients suffering from acupuncture. The needle is hidden both before and after delivery of the injection solution, appearing only during the injection. Mini-needle devices can usually deliver more drug than needleless devices, and can deliver faster than known needle systems.

One such known device is described in WO 00/09186 (Medi-Ject Corporation), “Needleless Needle Injection Device with Initial Needle Insertion,” and this document provides a useful overview of known devices.

The device of WO 00/09186 includes a needle, which in one embodiment is retractably in the assembly of an injector tip. When the source of force is triggered, part of the needle passes beyond the tip assembly and penetrates the outer layer of the skin to deliver the drug by injection into a deeper area. After the injection, the needle is pulled back into the tip assembly. A retractable needle is located in the tip and pushed forward to exit the tip in order to deliver the injection solution of the liquid drug itself when the drug itself is pushed forward by the piston.

Although the present invention may relate to injection devices with a mini-needle or devices for needleless injection, the invention is equally applicable to other types of injection devices, for example, devices for deep penetrating muscle injection, as well as devices intended for less deep - subcutaneous - injections.

In accordance with a first aspect of the present invention, there is provided an injection device having an outer case within which are located

a cylinder for holding a certain volume of the drug;

a needle at one end of the cylinder, the needle and the cylinder being made such that at least a portion of the needle can move axially to and from the specified outer case, but is normally completely displaced into the indicated case;

a piston that can move axially in the cylinder;

the inner housing between the outer housing and the cylinder and the piston and

an energy source interacting with said inner body,

moreover, the inner housing can be moved by an energy source between three positions, namely:

a first position in which the inner housing interacts with the piston and cylinder in such a way that, when used, the piston and cylinder can move in the axial direction to extend at least a portion of said needle from the outer housing;

a second position in which the inner case interacts with the piston but does not interact with the cylinder, so that when used, said piston can move axially into said cylinder to push the drug through the needle, and

the third position, in which the inner case does not interact with either the piston or the cylinder in such a way that, when used, the piston and cylinder can be retracted to draw the needle into the outer case.

The proposed injection device provides a simple and cost-effective means of drug delivery through a retractable needle. If necessary, this device is able to deliver the drug to a depth exceeding the length of the needle due to the driving force created by the energy source. As already noted, this injection device is equally suitable for needleless injection with a needle (drug delivery to a depth exceeding the length of the needle), for a normal injection (to the depth of penetration of the needle), or even to a depth of penetration of the needle that is user-adjustable.

For the operation of this device, it is necessary that the needle (and therefore the cylinder to which it is usually attached) moves axially so that the needle can extend beyond the tip end for the duration of the injection, after which it automatically retracts, invisible to the user. In addition, for the operation of this device, it is necessary that the piston moves in the axial direction (in the cylinder) in order to push the drug. The overall complexity of the injection device is significantly reduced if both of these requirements are met by a single component, namely the inner case.

Preferably, the injection device also comprises a spring housing between the outer housing and the inner housing.

The specified inner casing has one or more ears, each of which is preferably located on the end of the elastic elastic legs.

Preferably, one or more of these ears are located at the rear end of the inner housing and can move radially into and out of interaction with the piston. In one embodiment, the ears are offset radially inward to interact with the piston, preferably by interacting with the outer casing or the spring casing. Alternatively, prior to the injection, the ears are in their unstressed state during storage.

Each rear ear can go out of interaction with the piston when it coincides with the corresponding groove in the outer casing or the spring casing. Preferably, each hind eye is substantially T-shaped. One T-shaped shoulder allows the rear ear to engage over the piston and effectively pull the piston forward (in the aforementioned first and second positions). The other shoulder of the T-shape allows the rear ear to move radially outward to grip in a groove in the housing (in the aforementioned third position).

Preferably, one or more of these ears is located on the front end of the inner housing and can move radially into and out of interaction with the cylinder. In one embodiment, the front ears are offset radially inward in interaction with the cylinder, preferably by interacting with the outer casing or the spring casing. Alternatively, before starting the injection, the front ears are in their unstressed state during storage.

Each front eye can go out of contact with the cylinder when it coincides with a corresponding groove in the outer casing or the spring casing. Preferably, each front eye is substantially L-shaped.

In one preferred embodiment, said energy source is compressed gas. Alternatively, the indicated energy source is a spring.

Preferably, the injection device also has means for allowing the inner case to move in the axial direction only forward relative to the outer case. In the ideal case, the specified tool is the implementation of teeth, ruffs, ratchet teeth or the like between the buildings.

Preferably, the injection device also comprises guiding means for guiding when using the relative axial movement of the spring housing and the outer housing, the guiding means preferably comprising one or more projections on said spring housing, which in use interact with corresponding recesses on the inner surface of said outer housing.

Preferably, said needle is biased by a spring between the cylinder and the outer casing to normally fit completely inside the casing.

In one embodiment, the needle is removable from the device, which is beneficial in applications where the device is reused (for example, if an ampoule with a reusable drug is used).

In yet another embodiment, said needle, cylinder, and piston are removable from said device. It is assumed that the proposed device could be assembled on a standard needle / cylinder / piston of a known type.

Preferably, the injection device also includes a removable needle cap that protects the needle during storage and prior to use.

Advantageously, said needle cap has means for pulling off a protective rubber sheath or the like after removing said needle cap from a device. Said tightening means may include a floating rivet between the needle cap and the protective rubber sheath or the like, which virtually prevents the transmission of torsional forces exerted on the needle cap to the specified rubber sheath or the like.

Preferably, the presence of said needle cap on said device serves as a safety lock that substantially prevents relative forward movement of said outer case.

In one preferred form, the injection device also contains a viewing window in the specified cylinder, coinciding with a viewing window in the specified outer casing, through which the user can see the specified drug before injection. Preferably, when used during injection, said inner case is moved between said inspection window in the outer case and said cylinder in order to hide the window into the cylinder from the user's view.

Preferably, the injection device includes means for issuing an audible and / or physical indication to the user that the injection is complete.

In accordance with a second aspect of the present invention, there is provided an injection device having an outer case within which are located

a cylinder for holding a certain volume of the drug;

a needle at one end of the cylinder, the needle and the cylinder being made such that at least a portion of the needle can move axially to and from the specified outer case, but is normally completely displaced into the indicated case;

a piston that can move axially in the cylinder;

the inner housing between the outer housing and the cylinder and the piston and

an energy source interacting with said inner body,

moreover, the inner housing can be moved by an energy source between two positions, namely:

a first position in which the inner case interacts with the piston but does not interact with the cylinder, so that when used, said piston can move axially into said cylinder to push the drug through the needle, and

a position in which the inner case interacts neither with the piston nor with the cylinder, so that when used, the piston and cylinder can be retracted to draw the needle into the outer case.

In accordance with a third aspect of the invention, there is provided an injection device having an outer casing designed to accommodate

a cylinder for holding a certain volume of the drug;

a needle at one end of the cylinder, and the needle and cylinder are made such that at least part of the needle can move in the axial direction to and from the specified outer casing, but is normally completely displaced into the casing,

a piston that can move axially in the cylinder,

characterized in that it also contains

the inner housing between the outer housing and the cylinder and piston;

an energy source interacting with said inner body,

moreover, the inner housing can be moved by an energy source between three positions, namely:

a first position in which the inner housing interacts with the piston and cylinder in such a way that, when used, the piston and cylinder can move in the axial direction to extend at least a portion of said needle from the outer housing;

a second position in which the inner case interacts with the piston but does not interact with the cylinder, so that when used, said piston can move axially into said cylinder to push the drug through the needle, and

the third position, in which the inner case does not interact with either the piston or the cylinder, so that when used, the piston and cylinder can be retracted to draw the needle into the outer case.

Below, preferred embodiments of the present invention are described in more detail, by way of example only, with reference to the accompanying drawings.

A brief description of the graphic material

Figure 1 is a General view with a local section, in which the injection device is shown in the state in which it is supplied to the user, with the exception of the removed needle cap.

The figure 2 in an enlarged view shows a detail of part of the device shown in figure 1.

Figure 3 is a General view with a local incision, in which the injection device is shown during the injection.

Figure 4 is an enlarged view showing a detail of a part of the device of Figure 3.

Figure 5 is a General view with a local section, which shows an injection device with a piston fully pressed into the cylinder.

Figure 6 is an enlarged view showing a detail of a part of the device of Figure 5.

Figure 7 is a General view with a local section in which the injection device is shown after use and safe for disposal.

Figure 8 is an enlarged view showing a detail of a part of the device of Figure 7.

Figure 9 is a General view of the device with a needle cap.

Figure 10 is a General view with a local section, which shows a detail of the cap of the needle.

Figure 11 is a General view with a local incision, which shows a detail of the cap of the needle at the time of its removal from the injection device.

Figure 12 is a schematic view showing the interaction between the ears 7A and the plunger 4 in one embodiment of the invention.

Figure 13 is a general view of the inner housing (also referred to as the "piston housing").

Figure 14 is a side view of the inner case shown in figure 13.

Figure 15 is a General view with a local section in which an alternative embodiment of the injection device is shown in the state in which it is supplied to the user.

The figure 16 in an enlarged view shows a detail of the rear end of the device shown in figure 15.

17 shows a detail of the interaction between the spring housing 41 and the rear side of the outer housing 30.

Figure 18 is a general view with a local incision, in which the injection device is shown with the needle cap removed immediately before injection.

Figure 19 is a general enlarged view with a local section, which shows the front of the device immediately before injection.

Figure 20 is a General view with a local incision, which shows the front of the device at the beginning of the injection.

Figure 21 is a General view in which the device is shown in the same state as in figure 20, i.e. at the beginning of the injection, with a needle emerging from the end of the device and a piston starting to move to the bottom of the cylinder.

Figure 22 is a General view with a local section, which shows an injection device with a piston fully pressed into the cylinder.

Figure 23 is a General view with a local incision in which the injection device is shown after use and with a needle drawn into the device.

Figure 24 is a General view of the assembled device with a needle cap.

Figure 25 is a schematic view of a portion of the front end of the device, which shows a spiral protrusion on the tip.

Figure 26 is a General view with a local section, which shows a detail of the cap of the needle.

Figure 27 is a General view with a local incision, which shows a detail of the cap of the needle after removal from the device.

Throughout the text of the description below, the “forward” direction means the direction toward the patient when using an injection device. The “front” end of the injection device is the end closest to the patient’s skin when using the device. Similarly, the “back” direction means the direction from the patient, and the “rear” end of the device is the end farthest from the patient’s skin when using the injection device.

Figure 1 is a General view with a local section in which the injection device is shown in the state in which it is supplied to the user, with the exception of the removed needle cap (which is described below after describing the principle of operation of the device).

The main components of the device are described with reference to figures 1 and 2. At the rear of the device, an energy source 1 is provided, which in this embodiment is a compressed gas canister of a type similar to that used in a conventional aerosol can or similar type, i.e. having a valve through which gas can be purposely and in a controlled manner discharged. In an alternative embodiment, a spring is used as an energy source instead of a can of compressed gas, and this embodiment is described later with reference to FIGS. 13 and all subsequent ones. The valve 2 of the can of compressed gas opens into the chamber 3, which in figure 1 has a relatively small volume. The front side of the chamber 3 is formed by a plunger 4, which in its rear has an annular seal 5 so that the chamber 3 is gas-tight. The rear wall of the chamber 3 is formed by the rear side of the generally cylindrical body 6 of the camera.

The front of the plunger 4 abuts against the inner housing 7 (or, alternatively, is made integrally with it), which tightly surrounds the piston 8 (and therefore may be referred to as the “piston housing”). In the rear part of the piston body there are four orthogonally placed ears 7A, each of which has a “hammer head” or T-shape and whose tendency to straighten radially outward is limited by the diameter of the chamber body 6. If the plunger 4 is made integrally with the piston body 7, as shown in figures 13 and 14, the ears 7A are located at the end of the flexible legs cut into the body, and the ears 7A can be radially moved relative to the plunger 4 and the rest of the housing 7 .

The head of each eye 7A engages with the enlarged head 8A of the piston 8, and the ears 7A are in contact with the head 8A of the piston, as best shown in figure 2.

The piston 8 is the piston of a syringe device having a cylinder 9 into which a predetermined volume of liquid drug is supplied, and a needle 10 through which the drug can be delivered to the patient. Typically, the needle 10 is hidden from the patient’s eyes by the tip 11 at the front end of the injection device. A spring 12, located between the outer casing and the cylinder 9, biases the needle so that normally it is completely in the tip 11.

At the front end of the piston body 7 there are still another orthogonally placed ears 7B, each of which is usually L-shaped, and the tendency of which to straighten radially outward is limited by the diameter of the chamber body 6. Each of the ears 7B abuts against a flange at the rear of the cylinder 9.

Other means of interaction between the inner body and the piston can be provided, for example, instead of the ears 7A, the ears are not T-shaped, or the means that push the piston rather than retract, as in the described embodiment.

The device operates in four main stages. Stage 1 is the state shown in figures 1 and 2, i.e. in which the device is supplied to the user and described above. The drug is already in the cylinder 9, and the needle 10 is hidden from view in the tip 11. The piston 8 is completely extended from the cylinder 9 (due to the liquid drug contained in the cylinder), and the piston head 8A abuts the ears 7A. The back of the rest of the housing 7 abuts against the plunger 4. The chamber 3 has a minimum volume.

The 2nd stage of action is the injection stage, illustrated in figures 3 and 4. The injection device is pressed against the patient’s skin at the injection site, and a downward force is applied to the device in the direction shown by the arrow F in figure 3. This force causes the valve of the canister of compressed gas 1 to open, and gas escapes into the chamber 3. As the chamber 3 is filled with gas, the plunger 4 moves forward, forcing the ears 7A to act on the piston 8. As the ears 7A and, therefore, the piston body 7 move forward, the interaction of the ears 7B and the cylinder 9 leads to the fact that the cylinder also moves forward, overcoming the biasing force of the spring 12 (shown in figure 3). As the cylinder 9 moves forward, the needle 10 attached to it moves forward, and the needle protrudes from the tip 11 enough to deliver the injection solution. Thus, initially, the plunger 4 causes the piston body 7, the piston 8, the cylinder 9 and the needle 10 to move forward.

Soon after the piston body 7 begins to move forward, the ears 7B reach the edge in the chamber body 6. The ears 7B straighten out radially outward through this edge, as shown in Figures 3 and 4. After that, the ears 7B straighten outward so that they no longer abut cylinder 9. This means that cylinder 9 (and therefore the needle 10) is no longer moves forward because the forward-moving piston body 7, including the ears 7B, can freely continue moving forward without contact with the cylinder 9.

In this case, after the device has reached the state illustrated in figures 3 and 4, the continued forward movement of the plunger 4 and the piston body 7 causes the forward movement of the piston 8 into the cylinder 9. In this case, the liquid drug is expelled from the cylinder 9 and through the needle 10 for delivery injection solution. The forward-directed force from the plunger 4 / housing 7 to the piston 8 is transmitted due to the interaction of the ears 7A with the enlarged piston head 8A.

The third stage of action of the device is shown in figures 5 and 6. When the piston 8 is pressed into the cylinder 9, the patient is delivered the required dose of the drug. At this point, the ears 7A reach the grooves 13 cut out in the piston body 6, and in doing so, they can straighten out radially outward into these grooves (as shown in figures 5 and 6). There may be an audible click that indicates to the user that the injection is complete. In addition, the user can “feel” that the injection is complete, because the ears 7A are in the grooves 13.

Moving the ears 7A outward means that the shape of the “hammer head” is no longer in contact with the enlarged head 8A of the piston 8, and therefore, the piston 8 is no longer fed forward by the plunger 4 and the ears 7A. The piston body 7 may continue to move forward until it reaches the end stop.

The final stage of the device’s action is shown in Figures 7 and 8. The ears 7A are in the grooves 13, and no part of the piston body 7 interferes with either the piston 8 or the cylinder 9. Therefore, the spring 12, compressed by moving the cylinder 9 forward, moves the cylinder 9 and therefore, the piston 8 is back, until their further movement back stops the plunger 4. This movement back is sufficient for the needle 10 to be drawn into the tip 11, and at the same time it is already visible to the user, and there is no risk of damage to the adhering needle. The used injection device can then be safely disposed of.

Back impact is prevented by the implementation of the teeth 14, which direct the relative movement of the camera body 6 and the outer case. These teeth allow relative movement in only one direction, i.e. moving the camera body 6 forward relative to the outer case.

Figure 9 is a General view of the injection device, which in this figure has a cap 15 of the needle. In more detail, the needle cap is shown in figures 10 and 11 and it is intended to protect the tip of the needle of the injection device during transportation, storage and before use for delivery of the injection solution. The needle cap 15 has another advantage: it prevents accidental or unintentional activation of the device, since if the needle cap 15 is in place, it is impossible to turn on the device.

In accordance with the requirements of sanitary standards, the needle (which directly communicates with the drug in the cylinder) must be hermetically isolated from the external environment before use. This requirement is fulfilled by providing protection in the form of a rubber casting 16, which covers the tip of the needle, and the rubber casting 16 is surrounded by a nylon sheath 17. The rubber casting and the nylon sheath (hereinafter “needle protection”) are fastened together by a friction fit between one or more protrusions 16A on a rubber casting and corresponding one or more grooves 17A in a nylon sheath.

The configuration of the needle guard depends on the type of needle / cylinder / piston (hereinafter “syringe assembly") used in the injection device. The proposed injection device could be assembled on a standard syringe assembly of a known type (the choice of which depends, for example, on the required dose limits, type of drug administered, etc.). Different syringe assemblies can be delivered with slightly different needle protection.

The nylon sheath and rubber casting are firmly attached to the needle 10, and it is difficult, if not impossible, for the patient to pull them off only with their fingers due to their location inside the tip 11. Therefore, an outer cap 15 of the needle is provided, which not only improves the appearance of the injection device to its use, but also performs the function of facilitating the removal of the nylon shell and rubber casting.

The needle cap 15 is held so that it can be removed at the front end of the injection device by fitting the annular protrusions 18 on a part of the device body into the grooves 19 on the inside of the needle cap. The protrusions 18 and the corresponding grooves 19 preferably extend along equally opposite parts of a length of 60 ° of the circumference of the tip 11.

The grooves 19 are located on one or more (preferably equal to each other) flexible legs 20, which are flexible compared to the rest of the needle cap 15, relative to the point P shown in figure 9. In front of each groove 19 there is an inwardly projecting tongue 21 on each flexible leg 20. Each tongue 21 abuts against the back of the nylon shell 17.

As shown in figure 11, if the needle cap 15 needs to be removed from the device, the user grabs the needle cap, preferably in a place having a texture or other means to improve the grip 22, and pulls in the direction indicated by the arrow in figure 11. The flexibility of the legs 20 allows the cap the needles to retract the protrusions 18, releasing them from the grooves 19. However, the flexibility of the legs 20 is minimal to prevent the tongues 21 from detaching from the back of the nylon shell 17.

Thus, by pulling the needle cap 15 in the direction shown by the arrow, the tabs 21 are pressed against the back of the nylon shell 17, and you can apply a force sufficient to separate the needle 10 from the rubber casting 16. In this way, the entire casting 16, the nylon shell 17 and the needle cap 15 can be removed from the injection device and discarded, after which the injection device is ready for use.

Other types of needle cap 15 suitable for the particular type of syringe assembly used in the device can be invented, for example, described below with reference to FIG. 25 and all subsequent ones.

Figures 13 and 14 show in more detail one embodiment of the inner housing 7, in which the plunger 4 is integral with the housing 7.

The inner casing is obtained by injection molding as an integral part having four orthogonally placed ears at its end. Each eye 7A, 7B is located at the end of an elastically elastic leg cut from the material of the body 7, and each leg (and its corresponding eye) can bend radially relative to the rest of the body 7.

The rear of the inner casing 7 is the equivalent of the plunger 4 described above. The plunger has an annular groove or recess 4A, in which the ball bearings 42 can be placed.

In addition, the inner housing 7 may have one or more guide means, which in the illustrated embodiment have the form of elongated protrusions 7C. These protrusions 7C interact with corresponding recesses on the inner surface of the outer case 30 and, when using the device, direct the relative axial movement of the inner and outer cases.

A spring embodiment of an injection device is described below with reference to FIG. 15 and all subsequent ones.

In this embodiment, there is typically a cylindrical outer case 30 extending the entire length from the back of the device to the needle cap 15. The can of compressed gas 1 and valve 2 are replaced by a spring energy source. As shown in particular in FIG. 16, a compressed spring 40 is provided at the rear of the device, located between the rear side of the spring housing 41 and the plunger 4. The spring 40 is held in its compressed state by one or more ball bearings 42 located in the annular groove 4A on the plunger 4, and the ball bearings 42 stuck between the outer casing 30 and are located in the holes 41C in the front of the spring housing 41. The spring housing 41 cooperates with the rear side of the outer housing 30 by means of the device shown in figure 17.

The spring housing 41 has elongated slots 41B and typically round openings 41C. On the corresponding part of the outer casing there are elongated protrusions 30B on its inner surface that extend into the slots 41B, as shown in FIG. 17. Ball bearings 42 (not shown in FIG. 17) enter the circular holes 41C.

As shown in FIG. 15, the front end of the outer case 30 is positioned flush with the needle cap 15 or abuts against it. This practically prevents any forward movement of the outer housing 30 relative to the housing 41 of the spring and other components.

In Figure 18, the needle cap is removed, and now the device can be attached to the user's foot (or other injection site) ready to start the injection. In figure 19, the front of the device at this stage is shown in more detail.

In figures 19 and 20, the front of the device is presented in more detail. In the front of the outer casing 30, two annular grooves 30A and 30A 'are provided on its inner surface. The spacer 50 is fixed relative to the tip 11 and other components inside the outer casing 30. The spacer 50 has an outer annular protrusion 51, which is initially located in the front groove 30A.

The front edge of the front groove 30A is usually blunted so that the protrusion 51 located therein (as shown in FIG. 19) did not allow the user to pull the outer housing 30 back from the spring housing 41, etc., which could dangerously open the internal components of the device. It is difficult for the user to apply a backward force sufficient so that the protrusion 51 passes over the blunt leading edge.

The rear edge of the front groove 30A and both edges of the groove 30A 'are curved or beveled.

In order to start the injection, the user takes the device by the outer casing 30 and moves forward of the outer casing 30 relative to the spring body 41. As shown in FIG. 20, a forward movement releases the protrusion 51 from the front groove 30A, and as the outer casing 30 moves forward relative to the spacer 50, the protrusion 51 engages in the rear groove 30A ′.

In figures 18 and 21, the interaction between the plunger 4, the ball bearings 42 and the housing 41, the spring is presented in more detail. In the first position, shown in figure 18, the ball bearings 42 are seated in the annular groove 4A in the plunger 4 and jammed in place in the holes 41C in the front of the spring housing 41.

In figure 21, the device is shown in the same position as in figure 20, i.e. in which the forward movement of the outer housing relative to the spring housing has led to the engagement of the protrusion 51 in the rear groove 30A '.

In this position, the spring housing 41 has moved closer to the rear side of the outer housing 30. This relative axial movement is sufficient for the holes 41C to move back to the undercut area 30A ″ within the outer housing 30. The ball bearings 42 can now move freely radially from the holes 41C and into the indicated undercut zone 30A ″ out of engagement with the plunger 4. The plunger 4 can now freely move forward in the direction shown by the arrow in figure 21 under the action of the spring 40.

By moving the plunger 4 forward, the inner housing 7 delivers the injection solution as described above. This is illustrated in FIG. 21 (2nd stage described above) and FIG. 22 (3rd stage described above).

Figure 23 shows the position in which the injection solution is already fully delivered and the needle is retracted back to the tip (final stage described above).

In an alternative embodiment (not shown), the ball bearings 42 are replaced by a movable joint that can move into the undercut region 30A ″ from engagement with the plunger 4.

In yet another embodiment (not shown), the protrusion 51 and the grooves 30A, 30A 'are replaced or supplemented by a ratchet device described below. The spring housing has an almost square cross section. Part of the inside of the outer casing 30 has a corresponding shape with a square cross section, and the spring casing fits snugly into the outer casing, but with the possibility of relative movement between them. The square cross section virtually eliminates their relative rotational movement. At least one surface of the spring cross-section spring housing has several ruffs, protrusions, ratchet teeth, or the like, which interact with an inwardly extending protrusion or eye on the inside of the outer case.

The ratchet device performs the same function as the protrusion 51 and the grooves 30A, 30A ', i.e. controls the forward movement of the outer housing 30 relative to the spring housing 41. A ratchet device can provide other benefits, for example:

- increased strength;

- rotational alignment between the spring housing and the outer housing;

- increased resistance to the backward force exerted by the user, with the force pushing the device into the injection site;

- increased resistance to the force exerted by the user to pull the outer casing back from the device, and the ratchet teeth allow the outer casing to move only forward;

- improved determination of the relative axial position of the outer casing and the internal components of the device.

Alternative embodiments are possible in which, instead of a square cross section, the spring housing has at least one flat surface on which ruffs, protrusions, ratchet teeth or the like are located; the rest of the spring housing may have any cross section, but the inner side of the outer housing must have a corresponding shape.

Figure 13 and the following illustrate other options for the injection device, which are equally applicable to the above embodiment with a can of compressed gas as an energy source.

The cylinder 9 may have a transparent window 9A, which when used is aligned with the window 32 in the outer case (see figure 24) so that the liquid drug can be seen. During the injection (i.e., when the injection device is turned on), the piston body 7 as it moves forward between the cylinder 9 and the outer case becomes visible. As the piston body 7 moves forward, it gradually hides the window 9a, thereby giving the user a visual indication of the progress of the injection. After completion of the injection, the window 9a can be completely hidden by the piston body 7. The piston body 7 can be brightly colored, for example red, to improve its visibility through window 30.

It is noted that plastics of the type that can be used to make the piston body 7 over time will tend to remember the position in which they are stored. For the operation of the device, it is important that the ears 7A correctly spring into engagement and out of engagement with the enlarged piston head 8A. To this end, as shown in FIG. 18, a beveled surface 31 is provided on the inside of the outer casing 30. This ensures that the ears 7A are stored in a “relaxed” position, i.e. spring-loaded radially outward with abutment against the outer casing 30, as shown in figure 18.

At the beginning of the injection, as shown in FIG. 21, the forward movement of the outer housing 30 relative to the piston body 7 causes the ears 7A to rise along the beveled surface 31 in engagement with the enlarged piston head 8A.

After the piston body 7 has moved forward sufficiently so that the ears 7A reach the grooves 13, the ears 7A will show an increased tendency to spring out to the position in which they were previously stored, thereby ensuring the efficient operation of the device.

In figures 26 and 27 presents an alternative embodiment of the cap 15 of the needle. In these figures, similar details are indicated by the same positions as in figure 11. In the embodiment of figure 26, the needle cap 15 is held so that it can be removed at the front end of the injection device by fitting the ring protrusions 11A on the outside of the tip 11 into the corresponding recesses on the inner side of the cap 15 needles.

The protrusions 11A may take the form of a single spiral protrusion, as shown in figure 25, or alternatively, several individual protrusions can be used.

At the front end of the needle cap 15, there is a floating rivet 35, which has backward jagged fingers 36 extending through an opening at the front end of the sheath 17.

The presence of protrusions 11A, serrated fingers 36 and the interaction of the tip with the needle cap 15 on the surface 15A all this means that in the case illustrated in figure 26, the axial movement of the tip 11 and its associated components relative to the housing 30 is excluded. This means the impossibility of unintentional inclusion devices with the needle cap 15 not yet removed.

If the needle cap 15 needs to be removed from the device, the user grabs the needle cap and pulls in the direction indicated by the arrow in Figure 26, while making a twisting movement so that the needle cap moves along the tip guided by the spiral protrusion 11A.

The floating rivet 35 allows you to unscrew the cap 15 of the needle so that it moves along the spiral protrusion 11A, and the sheath 17 does not spin, but simply pulls off the needle in the axial direction. This means there is no risk of damage to the needle by twisting.

By pulling the cap 15 of the needle 15 in the direction shown by the arrow, the jagged fingers 36 pull the sheath 17 with a force sufficient to disengage the needle 10 from the rubber casting 16. In this way, the entire casting 16, nylon sheath 17 and the cap 15 of the needle can be removed from the injection device and throw away, after which the injection device is ready for use. Removing the cap 15 of the needle has a second function: it provides free axial movement of the tip and others relative to the housing 30, which allows you to turn on the device, as described above.

When reaching the end of the protrusion 11A, the cap 15 of the needle 15 is disconnected from the tip 11, as shown in figure 27.

Another embodiment of the present invention is possible in which, after removing the needle cap 15, the needle is open. This embodiment may be suitable for users not suffering from acupuncture, and if the complexity (and therefore cost) of the device can be reduced by eliminating the need for the first stage (i.e. moving the needle forward from tip 11). From such an embodiment, the optional needle cap 15 can be removed. As already noted, the proposed injection device can be delivered separately, and then assembled on a standard syringe assembly (needle / cylinder / piston) of a known type.

In yet another embodiment, the proposed device could be easily adapted to work with a standard ampoule or vial of a drug (containing or containing a volume of a drug from which several doses of a user-defined volume can be obtained) instead of a syringe assembly. In this case, the needle could be removable and replaceable so that the device could be reused before emptying the ampoule with the drug.

Claims (30)

1. An injection device having an outer casing (30), within which are located
a cylinder for holding a certain volume of the drug;
a needle (10) at one end of the cylinder, and the needle and cylinder are made such that at least part of the needle can move in the axial direction to and from the specified outer case (30), but is normally completely displaced into the indicated case;
a piston (8) that can move axially in the cylinder;
an inner case (7) between the outer case and the cylinder and the piston and
an energy source (1; 40) interacting with the specified inner casing (7),
characterized in that the inner housing (7) can be moved by an energy source between three positions, namely:
a first position in which the inner body has one or more radially elastic tabs (7B) that interact with the cylinder so that, when used, the piston and cylinder can move in the axial direction to extend at least a portion of said needle from the outer housing;
the second position, in which the inner case has one or more radially elastic ears (7A) that interact with the piston but do not interact with the cylinder so that when using the specified piston can move axially in the specified cylinder to push the drug through a needle; and
the third position, in which said one or more radially elastic ears (7A, 7B) on the inner case do not interact with either the piston or the cylinder in such a way that, when used, the piston and cylinder can be retracted to draw the needle into the outer case. 2. An injection device according to claim 1, further comprising a spring housing (41) between the outer housing (30) and the inner housing (7). 3. The injection device according to claim 1, characterized in that one or more of these ears are at the end of the elastic-elastic legs. 4. An injection device according to one of the preceding paragraphs, characterized in that one or more of these ears are located on the rear end of the inner housing and can move radially into interaction and out of interaction with the piston. 5. The injection device according to claim 4, characterized in that said ears are radially displaced inward in interaction with said piston, preferably by interacting with said spring housing. 6. The injection device according to claim 1, characterized in that before the injection, these ears are stored in their unstressed state during storage. 7. The injection device according to claim 6, characterized in that each rear ear can go out of interaction with the piston when it coincides with the corresponding groove in the spring body. 8. The injection device according to claim 7, characterized in that each rear ear is practically T-shaped. 9. Injection device according to one of paragraphs. 1-3, characterized in that one or more of these ears are located on the front end of the inner casing and can move radially into interaction and from interaction with the cylinder. 10. The injection device according to claim 9, characterized in that said front ears are shifted radially inward to interact with said cylinder, preferably by interacting with a spring body. 11. The injection device according to claim 10, characterized in that prior to the injection, said front ears are in their unstressed state during storage. 12. The injection device according to claim 11, characterized in that each front eye can get out of interaction with the cylinder when it coincides with a corresponding groove in the spring housing. 13. The injection device according to item 12, characterized in that each front eye has an almost L-shape. 14. Injection device according to one of claim 1 or 3, characterized in that said energy source is compressed gas. 15. Injection device according to one of claims 2, 5-8 or 10-13, characterized in that the specified energy source is a spring. 16. The injection device according to clause 15, also containing means that allows the inner casing to move in the axial direction only forward relative to the outer casing. 17. The injection device according to clause 16, characterized in that said means is the implementation of teeth, ruffs, ratchet teeth or the like between the bodies. 18. The injection device according to claim 17, further comprising guiding means for guiding when using the relative axial movement of the spring housing and the outer housing, the guiding means preferably comprising one or more protrusions on said spring housing, which in use interact with corresponding recesses on the inner surface of the specified outer casing. 19. The injection device according to p. 18, characterized in that said needle is biased by a spring between the cylinder and the outer and (or) inner case, so as to be completely completely inside the specified case. 20. The injection device according to claim 19, characterized in that the needle is removable from the specified device. 21. The injection device according to claim 20, characterized in that said needle, cylinder and piston are removable from said device. 22. An injection device according to one of the preceding claims, further comprising a removable needle cap that protects the needle during storage prior to use. 23. The injection device according to item 22, wherein the specified needle cap has a means for pulling off the protective rubber sheath or the like after removing the specified needle cap from the device. 24. The injection device according to item 23, wherein the specified means for tightening includes a floating rivet between the cap of the needle and a protective rubber sheath or the like, due to which the transmission of torsional forces exerted on the specified cap of the needle to the specified protective rubber sheath or like that. 25. Injection device according to one of paragraphs. 22-24, characterized in that the presence of the specified needle cap on the specified device serves as a safety lock, practically preventing the relative forward movement of the specified outer case. 26. The injection device according A.25, also containing a viewing window in the specified cylinder, coinciding with the viewing window in the specified outer casing, through which the user can see the specified drug before injection. 27. The injection device according to p. 26, characterized in that when used during injection, the specified inner casing moves between the specified viewing window in the outer casing and the specified cylinder to hide the window into the cylinder from the user's view. 28. The injection device according to item 27, containing also a means for issuing a sound and (or) physical indication to the user that the injection is complete. 29. An injection device having an outer casing within which are located
a cylinder for holding a certain volume of the drug;
a needle at one end of the cylinder, the needle and the cylinder being made such that at least a portion of the needle can move axially to and from the specified outer case, but is normally completely displaced into the indicated case;
a piston that can move axially in the cylinder;
an inner casing between the outer casing and the cylinder and the piston and an energy source interacting with the specified inner casing,
characterized in that the inner housing can be moved by an energy source between two positions, namely:
the first position, in which the inner case has one or more radially elastic ears that interact with the piston but do not interact with the cylinder so that when using the specified piston can move axially into the specified cylinder to push the drug through the needle; and
the second position, in which these one or more radially elastic ears on the inner case do not interact with either the piston or the cylinder so that, when used, the piston and cylinder can be retracted to draw the needle into the outer case. 30. The injection device according to clause 29, having all the distinguishing features according to one of paragraphs.2-28.

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