RU2810138C2 - Device for blocking syringe piston rod after use and for preventing reuse of syringe assembled with syringe - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention relates to devices for pumping fluid. The device is provided with a piston rod locking portion to lock the syringe piston rod after use and to prevent reuse of the syringe. A chamber is formed within the locking portion of the syringe plunger rod to receive the disk-shaped proximal end of the plunger rod after use of the syringe. The locking portion of the piston rod consists of at least one rigid locking device configured to firmly lock the axial position of the piston rod by accurately locking into the disc-shaped proximal end of the piston rod and retaining the disc-shaped proximal end of the piston rod within the chamber.

EFFECT: locking device provides the functions of a piston rod locking device to control the fact of use after administering a dose of the medicinal product by pressing the piston rod to prevent unintentional reuse of the syringe.

19 cl, 9 dwg

Description

Field of invention

The present invention relates generally to drug delivery devices and containers, and in particular, it relates to a piston rod locking device for locking the position of a syringe piston rod in the forward axial position (or in a position close to the forward axial position) of the distal end of the piston rod in the syringe barrel after using the syringe to prevent reuse of the syringe. A further aspect of the present invention relates to a syringe assembly including such a locking device.

Prior Art

Traditional syringes, which are typically made of plastic or preferably glass, consist of a syringe barrel having an open proximal end and an opposing distal end. Between these two ends there is a wall of cylindrical cross-section, forming a chamber that holds the substance. An elongated syringe cannula extends from the distal end of the syringe barrel and includes a narrow channel in communication with the substance-retaining chamber of the syringe barrel. The syringe plunger may be inserted into the open proximal end of the syringe barrel to move in tight connection with the wall of the cylindrical chamber, preventing fluid from flowing and sealing the syringe barrel. When the piston slides towards the distal end, the liquid is pushed out of the chamber through the channel into the cannula of the syringe to introduce the liquid into the body. Conversely, when the piston slides toward the proximal end, liquid is sucked through the channel in the cannula and enters the chamber of the syringe barrel.

One skilled in the art will appreciate that syringes are intended for single use only, in particular to address the spread of diseases associated with the inadvertent reuse of syringes, as well as to prevent their misuse.

For this purpose, US Pat. No. 5,358,497 describes a medical interlock device that is provided with a centrally located hole to receive a syringe plunger rod. The retaining element is located around the opening and receives the syringe finger stop, engaging with at least three sides of the stop, eliminating the possibility of displacement of the medical locking device. Opposite cutting elements are located along the chord of the hole. The cutting elements taper towards the end to thin cutting edges that can wedge into the piston when the locking position is reached. If the user turns the piston to the lock position, the cutting edges become wedged into the piston. This locking position eliminates and prevents the piston from moving in any direction along the longitudinal axis. The device can be used as a kind of means of monitoring the fact of using a syringe to prevent its reuse.

US Patent 8,066,668 B2 describes a syringe with a passive anti-reuse feature that uses a flange lock including a locking device. The piston assembly is located at least partially within the syringe barrel, including an extended piston rod having a locking flange molded thereon. A piston head having a distal sealing surface is engaged with the piston rod such that the piston head can move within the syringe barrel chamber during the injection cycle. The flange retainer is located at the open proximal end of the cylinder. The flange retainer is integral with the open proximal end of the syringe barrel. During the injection cycle, the flange retainer engages the plunger rod locking flange in a manner that prevents the plunger rod from being removed from the syringe barrel.

US Pat. No. 2005/070854 A1 describes a syringe. To prevent reuse of the syringe after drug administration, a plastic ring is clamped onto the flared rim at the rear end of the syringe using a ring clamp. The rear end of the ring consists of an annular wall forming a cylindrical recess, the size of which allows the mushroom-shaped piston handle to be received at or near the forwardmost axial position of the piston. The inner circumference of the annular wall is slightly larger than the circumference of the mushroom handle and is sized to accept the handle with a tight fit without leaving any surface on the handle for the user to grip. Thus, the user does not have the ability to extend the piston after the handle has passed the end of the wall. Accordingly, the possibility of reusing the syringe is eliminated due to the geometric configuration of the ring, and not due to the friction stopper.

US patent 2017/239425 A1 syringe with a retractable needle. In the embodiment of the invention shown in FIG. 13 and 14, the piston locking function is provided by precision locking engagement elements located at the proximal end of each syringe barrel and piston to prevent the piston from being removed from the syringe barrel once the piston is engaged. The precision-fit engagement elements are integrally formed with the proximal end of each syringe barrel and plunger, respectively.

US Pat. No. 6,679,863 B2 describes a precision-fit handle locking upon closure at the proximal end of the piston at or near its forward axial position, which is similar to the locking described in US Pat. No. 2017/239425 A1.

The essence of the invention

An object of the present invention is to provide a simple and inexpensive integral plunger rod locking device for locking the position of a syringe plunger rod in the forward axial position (or near the forwardmost position) of the distal end of the plunger rod within a syringe barrel after use of the syringe and in preventing reuse syringe. It is a further object of the present invention to provide a syringe assembly consisting of a syringe barrel, a piston and a piston rod configured to lock the position of the syringe piston rod at the axial most forward position (or a position close to the forward axial position) of the distal end of the piston rod within the barrel. syringe after using the syringe and preventing reuse of the syringe.

In accordance with the present invention, there is provided a device for locking a syringe plunger rod after use, wherein the syringe has a barrel with an open proximal end and a flange provided adjacent said open proximal end, and wherein the barrel is configured to receive the plunger rod through said open proximal end. end, and the proximal end of the piston rod is disc-shaped. The locking device is comprised of a mounting portion configured to allow the locking device to be mounted with a precise fit when locked onto a flange adjacent to said proximal end, and a piston rod locking portion for fixing the axial position of the piston rod after use of the syringe, wherein the locking device is formed a connecting channel allowing the piston rod to be inserted into the open proximal end of the cylinder through the piston rod locking portion and the mounting portion.

In accordance with the present invention, the width of the connecting channel within the locking portion of the piston rod is made larger, which makes it possible to create a chamber or space for receiving a disk-shaped proximal end of the rod after use of the syringe, wherein the locking portion of the piston rod consists of at least one clear device locking device configured to rigidly lock the axial position of the piston rod by engaging in a precise locking fit with the disc-shaped proximal end of the piston rod to lock the piston rod at or near the extreme axial position of the distal end of the piston rod inside the syringe barrel after using the syringe.

Thus, in accordance with the present invention, the locking device provides the functions of a syringe-controlling piston rod locking device to securely lock the piston rod at the proximal end of the barrel after administering a drug dose by pressing on the piston rod to prevent repeated unintentional use of the syringe. The plunger rod locking portion reliably prevents the plunger rod from being withdrawn from the syringe barrel back past the area of at least one locking device provided in the plunger rod locking portion because the disc-shaped proximal end of the plunger rod remains in the chamber or receiving space and the proximal end is accessible. the piston rod outside the chamber or receiving space is limited by the side walls or enclosing ribs of the blocking part of the piston rod.

To administer a dose of medication, the user will intuitively use the disk-shaped portion to press the plunger rod toward the distal end of the syringe barrel. Since the disc-shaped portion is provided at the outermost portion of the proximal end of the plunger rod, in accordance with the present invention, the locking device provides an intuitive and unambiguous indication of the use of the syringe: a) if the disc-shaped proximal end of the plunger rod is completely located in the locking portion of the plunger rod and, as a result, does not protrude beyond the proximal end of the locking part of the piston rod, for the user this will be a clear and unambiguous sign that the syringe has already been used; b) on the other hand, if the piston rod is in a fully extended position depending on the dose of drug injected into the syringe barrel, this will be a clear and unambiguous indication to the user that the syringe has not yet been used; (c) An intermediate position of the disc-shaped portion of the plunger rod between the fully retracted position (locked position) and the fully extended position will provide a clear and unambiguous indication to the user that the syringe has already been used, and therefore the user should exercise caution when using the syringe.

In particular, locking the disc-shaped proximal end of the piston rod within the chamber or receiving space of the locking portion of the piston rod makes it possible to clearly, unambiguously and intuitively distinguish an unused syringe or a syringe that has been partially used, as well as the state after use of a syringe with complete or almost complete drug administration. the agent with which the syringe barrel was originally filled. After use of the syringe, the disc-shaped proximal end of the plunger rod is essentially locked into the chamber or receiving space of the locking portion of the plunger rod, rendering its further use impossible.

The forwardmost axial position of the piston rod inside the syringe barrel may be identical to the axial position of the piston inside the syringe barrel if the piston rod is rigidly locked without play in the axial direction. According to yet another embodiment of the invention, the plunger rod may also be rigidly locked with a certain clearance in the axial direction, in which case the plunger rod and rod may be pushed further toward the distal end of the syringe barrel, thereby allowing the remaining dose of liquid to be administered within by applying additional pressure on the piston rod towards the distal end of the syringe barrel after moving the proximal end of the piston rod beyond the area of at least one rigid locking device. According to the present invention, the function of reliably preventing reuse of a syringe can be realized at a lower cost and with less space requirements by using a one-piece device. According to the present invention, the locking device can be used easily and intuitively. The locking function can be checked visually, in particular, even untrained personnel can easily determine the locking position indicating the fact of use. Even if personnel do not have to determine the locking position of the piston rod, reuse of the syringe is reliably prevented.

In accordance with another embodiment of the invention, the locking part of the piston rod is made integral with the mounting part. Thus, according to the present invention, the locking device can be implemented as an integral element, for example, using plastic injection molding technology.

According to another embodiment of the invention, the locking portion of the piston rod consists of a cylindrical side wall and at least one rigid locking device located on the inside of the cylindrical side wall. The cylindrical side wall additionally provides the function of preventing unauthorized access to the piston rod immediately after the piston rod is firmly locked by at least one rigid locking device, since due to said locking, access to at least one rigid locking device from outside the locking part of the piston rod can be reliably prevented. changing the position of at least one hard locking device. After use, the disc-shaped portion at the proximal end of the piston rod will not protrude beyond the proximal upper rim of the cylindrical side wall blocking portions of the piston rod.

In accordance with another embodiment of the invention, a stop surface is provided at the bottom of said chamber for establishing the anteriormost axial position of the distal end of the piston rod in the cylinder by means of a disc-shaped stop of the proximal end of the piston rod into this stop surface. The abutment surface reliably prevents the disc-shaped proximal end of the piston rod from being further pressed past the abutment surface. At the same time, the thrust surface, which can be formed as a ring, can further increase the mechanical strength and stability of the chamber or receiving space of the locking portion of the piston rod.

In accordance with yet another embodiment of the invention, the at least one rigid locking device is configured to retain the disc-shaped proximal end of the piston rod within the chamber and prevent the disc-shaped proximal end of the piston rod from being withdrawn toward the proximal end of the locking portion of the piston rod by the limits of the area located at a minimum distance from the proximal upper rim of the locking portion of the piston rod when the axial position of the piston rod is rigidly fixed, and the minimum distance corresponds to at least the axial length of at least one rigid locking device. This minimum distance from the disc-shaped proximal end to the proximal upper rim of the piston rod locking portion further assists in preventing access to the disc-shaped proximal end for unauthorized manipulation once the disc-shaped proximal end is secured within the chamber or receiving space of the piston rod locking portion. due to locking with precise fit when closing.

In accordance with another embodiment of the invention, the chamber formed by the locking portion of the piston rod is configured to prevent full access to the disc-shaped proximal end of the piston rod from outside the locking portion of the piston rod, to prevent the disc-shaped proximal end of the piston rod from being withdrawn from the chamber or receiving space after rigid fixation of the axial position of the piston rod. For this purpose, the locking part of the piston may be formed by a cylindrical side wall, and at least one rigid locking device is provided on the inner side of the cylindrical side wall, or the locking part of the piston rod may be formed by a cylindrical sleeve-shaped element formed by two annular ribs, connected to each other by axial connecting ribs, wherein at least one rigid locking device is provided on the inside of the annular rib or the axial connecting rib.

In accordance with yet another embodiment of the invention, the at least one rigid locking device is formed in the form of a locking projection that extends radially into the locking portion of the piston rod and is configured to engage the disc-shaped proximal end of the piston rod with a precise fit when engaged. In this case, the disc-shaped proximal end of the piston rod represents a locking portion of the piston rod with a maximum outer dimension that can be easily secured by at least one locking projection projecting into the interior volume of the locking portion of the piston rod. Naturally, in accordance with other embodiments of the invention, rigid locking of the piston rod can also be implemented by other rigid locking devices, for example, a rack provided adjacent the proximal end of the piston rod.

In accordance with yet another embodiment of the invention, at least one locking projection is formed in a window or cutout formed in the cylindrical side wall, and each of the locking projections has a beveled upper surface facing the proximal open end of the piston rod locking device, as well as a lower portion, protruding radially inward and perpendicular to the cylindrical side wall. The locking projection may be formed as an elastic plate-like member hinged at one end on the inner surface of the cylindrical side wall so that the proximal end of the piston rod can be locked within the locking portion of the piston rod with a slight force by simply moving the proximal end of the piston rod ( which is preferably disc-shaped) behind at least one locking protrusion, thereby deflecting or bending the blocking protrusion outward towards the cylindrical side wall.

In accordance with yet another embodiment of the invention, the width of the connecting channel is made greater within the locking portion of the piston rod to form a chamber for receiving the disc-shaped proximal end of the piston rod, and a stop surface is provided at the bottom of said chamber to limit or establish the forwardmost axial position of the rod. piston inside the syringe barrel. Thus, the disc-shaped member at the proximal end of the piston rod may be slightly wider than the shaft portion of the piston rod to allow the proximal end of the piston rod to be easily locked into a precise locking fit by at least one locking projection. At the same time, the lower part of the chamber of the blocking part of the piston rod serves as a stop for accurately establishing the extreme forward position of the proximal end of the piston rod inside the chamber of the blocking part of the piston rod and, as a consequence, the extreme forward position of the rod inside the syringe barrel.

According to another embodiment of the invention, the height of the chamber in the axial direction of the locking device is greater than the thickness of the disc-shaped proximal end of the piston rod. Thus, the residual dose of liquid can be administered by pressing the plunger rod toward the distal end of the syringe barrel after the disc-shaped proximal end has moved beyond the locking projections until the disc-shaped proximal end abuts the abutment surface of the locking portion of the plunger rod defining the extreme forward axial position of the piston inside the syringe barrel.

According to another embodiment of the invention, the mounting part consists of an upper plate directed toward the proximal end of the connecting channel, a lower plate opposite said upper plate, and an intermediate space formed between the upper and lower plates. Thus, the shape of the two plates can be easily matched to the shape of the finger support or flange provided at the proximal end of the syringe barrel, thereby providing an intuitive and easy installation of the locking device. In particular, the shape of the two plates may provide a precise fit of the mounting portion with a finger rest or flange provided at the proximal end of the syringe barrel, particularly by securing the mounting portion to the finger rest or flange.

In this case, at least one projection is provided to reduce the width of the connecting channel to a size less than the maximum outer dimension (in particular, the outer diameter) of the piston inserted into the syringe barrel. Thus, according to the present invention, the locking device also provides a stop stop function to prevent the plunger rod from being unintentionally withdrawn from the syringe, since in a state where the position of the plunger rod is not yet fixed by the locking portion of the plunger rod, the rearward movement of the plunger rod will be automatically stopped after the piston will come into contact with the at least one protrusion in the connecting channel, thereby preventing further movement of the piston towards the proximal end of the syringe barrel beyond the predetermined end position defined by the at least one protrusion in the connecting channel.

Such protrusion (at least one) may be formed as a semicircular edge at the proximal end of the mounting portion projecting from the top plate into the intermediate space. The shape of the raised semi-circular edge may help ensure an accurate fit when the mounting portion is locked to the finger rest or flange provided at the proximal end of the syringe barrel, since the raised semi-circular edge may be slightly resilient and, as a result, may flex slightly when the mounting part is pressed against the finger support. fingers or syringe barrel flange. In this case, the shape of the semicircular edge can be accurately matched with the shape of the outer surface of the syringe barrel at the proximal end, thus acting as a stop when pressing the mounting part on the finger rest or the flange of the syringe barrel to establish the initial fixed position of the locking device on the support for fingers or the flange of the syringe barrel.

According to yet another embodiment of the invention, the semicircular edge may have a tapered profile with an outer diameter corresponding to the inner diameter of the syringe barrel at the open proximal end. If necessary, the tapered profile can further facilitate the movement of the piston rod axis along the semicircular edge when inserting the piston rod into the syringe barrel. In particular, the plunger rod can be guided with reduced clearance within the connecting channel when inserted into the syringe barrel to connect with a plunger already present within the syringe barrel.

In yet another embodiment of the invention, the semicircular edge may have a tapered profile with an outer diameter corresponding to the inner diameter of the syringe barrel at the open proximal end. In this way, at least one protrusion, particularly a semi-circular lip, can be lightly inserted into the open proximal end of the syringe barrel to provide a secure, rigid locking of the mounting portion to the flange at the open proximal end of the syringe barrel. Namely, when at least one protrusion, in particular a semicircular edge, is inserted into the open proximal end of the syringe barrel, the possibility of inadvertent removal of the locking device from the flange of the syringe barrel is eliminated.

According to another embodiment of the invention, the height of the intermediate space formed between the upper and lower plates of the mounting part generally corresponds to the height of the flange at the open proximal end of the cylinder. Thus, the flange at the open proximal end of the syringe barrel can be clamped, or at least tightly seated, between the upper and lower plates of the mounting portion, which further assists in firmly locking the mounting portion onto the flange. Since in the preferred embodiment, at least one projection extends from the top plate of the mounting portion, for installation, at least one projection must be inserted into the open proximal end of the syringe barrel, which will further facilitate the rigid locking of the mounting portion to the flange, as described above.

According to another embodiment of the invention, at least the bottom end of at least one protrusion must be resilient or flexible, which can be achieved by molding the entire locking device from resilient plastic, in particular using injection molding technology. As a consequence, when installing the locking device on the flange at the open proximal end of the syringe barrel, at least one protrusion may be slightly deformed or bent, but it will return to its original unstressed state to ensure the mounting portion is securely locked on the flange as described above.

In accordance with a further aspect of the present invention, there is provided a medical grade syringe consisting of: a syringe barrel having a distal end, an open proximal end opposite the distal end, a side wall forming a chamber between the distal end and the open proximal end, and a flange provided adjacent with said open proximal end; a piston located inside the chamber of the syringe barrel; and a piston rod associated with and connected to the piston. In accordance with the present invention, the syringe assembly also consists of a locking device, described in more detail below, which prevents inadvertent removal of the plunger from the barrel of the syringe, and said locking device is mounted on a flange located adjacent to the above-mentioned proximal end with a precise locking fit.

Upon examination of the description of the present invention, it will be apparent to one skilled in the art that a plunger rod locking function may also be implemented in conjunction with a stop stop function to prevent inadvertent removal of the plunger from the syringe barrel. Thus, a further aspect of the present invention, also based on the above-described idea of a locking device capable of being claimed based on a separate independent set of claims, relates to a locking device for preventing the inadvertent removal of a plunger from a syringe, said syringe including a barrel with an open proximal end and a flange provided adjacent said open proximal end to said cylinder configured to receive a piston rod through said open proximal end including a mounting portion configured to install a locking device on the flange, and wherein the locking device is formed with a connecting channel to allow the plunger rod to be inserted into the open proximal end of the barrel, and at least one protrusion is provided to reduce the width of the connecting channel in sections to prevent inadvertent removal of the piston from the syringe.

According to this second independent aspect of the present invention, there is further provided a piston rod locking portion as described above for fixing an axial position of the piston rod, and wherein a connecting channel extends through the piston rod locking portion, and the piston rod locking portion is comprised of at least one device a rigid locking configuration configured to rigidly lock the axial position of the piston rod by engaging the proximal end of the piston rod or a portion of the piston rod adjacent to its proximal end to lock the piston rod in the forwardmost axial position (or in a position close to the most forward axial position) forward axial position) of the distal end of the piston rod in the cylinder.

Brief description of drawings

The invention will now be described by way of example and with reference to the accompanying drawings, from which additional features, advantages and problems to be solved will be identified.

On the drawings:

In FIG. 1a and 1b show a syringe barrel with a piston rod locking device in accordance with the present invention in a disassembled and installed state;

Fig. 2a shows a piston rod locking device according to the first embodiment of the present invention in front perspective;

Fig. 2b-2d show the piston rod locking device shown in FIG. 2a, in top view and in two side views;

Fig. 2e shows element A shown in FIG. 2d;

Fig. 2f shows the piston rod locking device shown in FIG. 2a, in perspective from the rear side;

Fig. 3 is a cross-sectional view of a piston rod locking device mounted at the proximal end of a syringe barrel in accordance with a second embodiment of the present invention;

Fig. 4a and 4b show the insertion of a piston rod into a syringe barrel with a locking device mounted at the proximal end of the syringe barrel in accordance with the present invention in perspective and in section;

Fig. 5a is a cross-sectional view of a syringe barrel in a position where the disc-shaped proximal end of the plunger rod is substantially locked in the plunger rod locking portion of the plunger locking device of the present invention;

Fig. 5b is a cross-sectional view of a syringe barrel when the disc-shaped proximal end of the plunger rod is locked in the plunger rod locking portion of the plunger locking device according to the present invention;

Fig. 6a is a cross-sectional view of the proximal end of a syringe barrel with a locking device in a substantially locked state with the piston rod in accordance with FIG. 5a;

Fig. 6b is a cross-sectional view of the proximal end of a syringe barrel with a locking device in the locked state of the piston rod in accordance with FIG. 5b;

Fig. 7a shows a piston rod locking device according to a third embodiment of the present invention in front perspective;

Fig. 7b-7d show the piston rod locking device shown in FIG. 7a, in top view and in two side views;

Fig. 7e shows element A shown in FIG. 7d;

Fig. 7f and 7g show a cross-sectional view of the proximal end of a syringe barrel with a locking device in a substantially locked state and in a locked state of the piston rod in accordance with FIG. 7a;

Fig. Figure 7h is a cross-sectional view of a syringe barrel when the disc-shaped proximal end of the plunger rod is substantially locked into the plunger rod locking portion of the plunger locking device in accordance with Figure 7a;

Fig. Figure 7i is a cross-sectional view of a syringe barrel when the disc-shaped proximal end of the plunger rod is locked in the plunger rod locking portion of the plunger locking device in accordance with Figure 7a;

FIG. 8a shows a piston rod locking device according to a fourth embodiment of the present invention from a front perspective view; FIG.

Fig. 8b and 8c show the piston rod locking device shown in FIG. 8a, in top and side views;

Fig. 9 is a side view of the proximal end of a piston rod of another embodiment of the present invention.

In the drawings, identical or substantially equivalent elements or groups of elements are designated by the same reference numerals.

Detailed Description of Preferred Embodiments of the Invention

As shown in FIG. 1a, a syringe 1 for use with a locking device in accordance with the present invention includes a syringe barrel 10 which is made of glass or plastic and is preferably transparent. The syringe barrel 10 includes an open proximal end 15 with a flange 13, a distal end 11, the barrel is a cylindrical body formed by a cylindrical side wall defining a substance receiving chamber that can be pre-filled with a selected dose of drug in dry or liquid form, and also other substances, for example, water or a diluent for use in diluting the medicinal product. The distal end 11 of the barrel of the syringe 10 includes a cannula with a channel 12 (see Fig. 4b), extends in the axial direction, and communicates with the substance receiving chamber 16. A piston rod (not shown) can enter the proximal end 15 of the barrel of the syringe 10 through an open proximal end 15 serves as a fill port and may include a piston (not shown) that can move within the cylindrical wall to form a tight engagement with it to seal the barrel of the syringe 10. Typically, the piston rod is releasably coupled to the piston, for example, using threads. The syringe barrel 10 can be used with a standard needle assembly (not shown), which is generally known in the art.

The built-in ring for securing the installation cannula of the needle assembly at the distal end 11 in the syringe barrel 10 is, as a rule, absent. For this purpose, a ring, in particular a Luer ring, can be installed on the syringe cannula at the distal end 11 of the syringe barrel 10.

The needle assembly may be maintained separately from the barrel of the syringe 10 and may be quickly installed on the barrel of the syringe 10 prior to use of the syringe 1. For example, the needle may be connected to the cannula of the syringe 11 using a luer lock. Thus, the barrel of the syringe 10 can be pre-filled with medication and stored in such a pre-filled state before installing the needle assembly.

However, the present invention should not be considered to be limited only to connecting the needle assembly to the barrel of the syringe 10, but the needle can also be secured to the cannula of the syringe 11 in a standard manner, such as by using adhesive.

To prevent contamination or leakage of the drug stored in the barrel of the syringe 10, the cannula of the syringe at the distal end 11 is typically sealed with an elastic cap (not shown). Preferably, the resilient cap is made of an elastomeric material and consists of a cylindrical body (not shown) that is inserted into the distal end 11 to seal it. To keep the resilient cap in position, in proper engagement with the syringe cannula at the distal end 11, and to prevent contamination of the resilient cap during storage, a tip cap assembly, such as that described in US Pat. No. 2013/0338603 A1, may be used at the distal end 11 of the barrel of the syringe 10. .

To seal the opposite proximal end 15 of the syringe 10 barrel, an elastic plug is inserted into the syringe 10 barrel through the open proximal end 15, which will be in tight engagement with the cylindrical wall of the syringe 10 barrel, thus ensuring the tightness of the substance receiving chamber.

At the opposite proximal end 15 of the barrel of the syringe 10, a flange 13 is provided to provide a type of finger rest to allow the user to manipulate the syringe during use. The flange 13 may have various shapes, for example a rounded shape as shown in FIG. 1a, or as is often seen, some sort of modified rounded shape that may include a pair of straight sides, which may be appreciated by one skilled in the art. The inner edge 14 of the flange 13 may be rounded, as shown in FIG. 1a. In general, the rounded inner edge 14 at the open proximal end may be funnel-shaped toward the inner surface of the cylindrical side wall 10, as shown in FIG. 1a.

To lock the plunger rod after use of the syringe and to prevent reuse of the syringe, a locking device, generally designated by reference number 2, is mounted on a flange 13 at the open proximal end 15 of the barrel of the syringe 10. The locking device 2 includes a mounting portion 40 configured to mate with the syringe barrel 10 by means of the flange 13, and is rigidly mounted on the flange 13. In particular, the locking device 2 can be secured by a certain minimum resistance to the flange 13 and can then be removed from the flange 13 again by applying a force exceeding this resistance.

Let us now turn to Fig. 2a-2f, in one embodiment of the locking device 2 in accordance with the present invention, the mounting portion 40 includes an upper plate 20 and a lower plate 21 spaced apart from each other in such a way as to form an intermediate space in the form of a pocket 23 with dimensions and configuration, ensuring tight placement of the flange 13 of the syringe 1 in this space. If desired, the bottom plate 21 can be removed to accommodate an extended portion of the top plate, which is fixed to the flange 13.

The intermediate space 23 may include a front opening 26 through which the flange 13 enters the intermediate space 23 to install a locking device 2 on the flange 13. The front opening 26 is configured and sized to allow the mounting portion 40 to be mounted over the flange 13 at various rotation angles. or with a different orientation between the flange 13 and the mounting part 40. The side walls 22 of the mounting part 40 can serve to connect the upper and lower plates 20 and 21, respectively, and allow the formation of an intermediate space 23. These side walls 22 can only be provided along the narrow sides blocking portion 40, as shown in FIG. 1a, or may be provided along the two narrow sides and additionally along the rear long side of the blocking portion 40. In general, the height of the intermediate space 23 corresponds to the axial length of the flange 13.

Although the top and bottom plates 20 and 21 are shown to be relatively flat, if desired, one or both plates may be concave so that the plates 20, 21 are free to flex in and out of the intervening space 23. Thus, either or both of the plates 20, 21 may flex as the mounting portion 40 of the locking device 2 is positioned around the flange 13, thereby compensating for any tolerance deviations, shape or surface discrepancies, or any other problems encountered with the flange 13. Thus , the mounting portion 40 may also exert a greater holding force on the flange 13 if such increased force is necessary and desired. A certain degree of deflection may help determine the minimum force required to install the mounting portion 40 onto the flange 13, particularly by clamping. Although not shown in the drawings, one skilled in the art will appreciate that the locking device may generally be sized and configured to allow the plates 20, 21 to be concave to achieve the same purpose.

Typically, the hole in the bottom plate 26 is configured and sized to provide intimate contact with the outer surface of the barrel of the syringe 10 at its open proximal end 15. The hole 26 and/or structure associated therewith defines a channel through the top plate 20, the width of which may be slightly less than the internal diameter defined by the open proximal end 15 of the barrel of the syringe 10, but which may also correspond to the internal diameter defined by the open proximal end 15 of the barrel of the syringe 10. As shown in this figure, the shape of the lower hole 26 is made relatively arcuate to ensuring compliance with the relatively cylindrical outer surface of the barrel of the syringe 10 at its proximal end 15. In particular, as shown in FIG. 2b, the inner edge 25 of the lower opening 26 in the lower plate 21 has a semicircular shape, the diameter of which is identical to the outer diameter of the barrel of the syringe 10 at its open proximal end 15, or which may be slightly smaller than this outer diameter.

In accordance with other embodiments of the invention, the width of the hole 26 formed in the top plate 20 may be slightly less than the outer diameter of the barrel of the syringe 10 at its open proximal end 15 to provide the additional function of a stop stop to prevent inadvertent removal of the piston rod after installing the locking device 2 on the flange. syringe, as described in more detail below, but this function is not an essential feature of the plunger rod locking device in accordance with the present invention. However, the shape of the hole 26 need not be so limited, as can be seen, the hole can be any shape consistent with the shape of the barrel of the syringe 10, such as an ovoid shape, a square shape, and the like.

To allow the locking device 2 to be inserted on the flange 13 and to allow the locking device 2 to be inserted regardless of the presence or absence of a piston, a guide edge 25a formed or otherwise cut into the plate 21 is provided on the inner edge 25 of the opening of the bottom plate 26. , the bottom plate 21 has a guide hole that connects to the hole 26 through an opposing pair of transition edges.

As shown in the sectional view in FIG. 2d, the inner edge 25 in the sectional view may have a truncated (truncated-conical) shape. The inner diameter of the truncated (truncated-conical) inner edge 25 may match the inner diameter of the barrel of the syringe 10 at its proximal end 15 or may be slightly larger. According to this alternative, the truncated (truncated-conical) inner edge 25 is not suitable for providing a stop stop function to prevent the plunger from being inadvertently removed from the syringe barrel after it has been inserted into the syringe barrel.

However, in accordance with yet another embodiment of the present invention, the outer diameter of the truncated (truncated-conical) inner edge 25 may correspond to the inner diameter of the barrel of the syringe 10 at its proximal end 15. In particular, the proximal end of the flange 13 typically abuts (or substantially abuts) into the inner surface of the upper plate 20, thereby ensuring a tight fit of the truncated (truncated-conical) inner edge 25 to the rounded inner edge 14 of the flange 13. For this, at least the lower end of the truncated (truncated-conical) inner edge 25 can also be elastic.

Due to the semi-circular shape of the inner edge 25 forming a hole 26 open towards one longitudinal side of the mounting part 40, the locking device 2 can be laterally pushed onto the flange 13 of the syringe 1. When the mounting part 40 with the semi-circular hole 26 is pushed onto the flange 13 of the syringe 1, the truncated (truncated-conical) inner edge 25 will flex and deform as it moves along the flange 13 of the syringe 1 until the truncated (truncated-conical) inner edge 25 is firmly inserted into the open proximal end 15 of the syringe to ensure reliable installation of the mounting part 40 on flange 13 with a tight fit when closed. In this position, with the piston rod (not shown in Fig. 2a 2d) passing through the connecting channel 29 into the open proximal end 15 of the syringe 1, the locking device 2 cannot be re-released from the flange 13. As will be apparent to one skilled in the art, when As the mounting portion 40 is pushed onto the syringe flange 13, the top plate 20 and/or bottom plate 21 of the mounting portion 40 may flex slightly, allowing the frustoconical inner edge 25 (or at least one projection 28 shown in FIG. 3) to move into the open proximal end 15 of the syringe 1 and rest, for example, on the funnel-shaped rounded inner edge 14 of the flange 13.

As shown in FIG. 2a and 2d, the mounting portion 40 is connected to a piston rod locking portion 30 located above the mounting portion 40. In particular, a relatively short cylindrical connecting portion 27 can be provided between the mounting portion 40 and the piston rod locking portion 30. Preferably, the piston rod locking portion 30 is formed integrally with the mounting portion 40, for example, using a plastic injection molding method. Alternatively, the piston rod locking portion 30 and the mounting portion 40 may be formed as separate members connected to each other by locking members, such as screws or bolts, or by other joining techniques, such as threading, adhesive bonding, or fusion. In this case, the locking part of the piston rod 30 is connected to the installation part 40, and a connecting channel 29 is formed in the locking device 2, the width of which is slightly larger than the outer diameter of the piston rod to allow the piston rod to be inserted vertically from above through the locking device 2 and this connecting channel 29 into internal volume of the syringe barrel.

Specifically, the locking portion of the piston rod 30 forms a cylindrical chamber or receiving space 37 defined by a cylindrical side wall 31 configured to receive the disk-shaped proximal end 50 of the piston rod 5 (see FIG. 4a) while locking the piston rod 5 at its extreme the forward axial position (or a position close to the extreme forward axial position) of the distal end of the piston rod 5 in the cylinder 10 after use of the syringe.

As shown in FIG. 2a-2f, the locking portion of the piston rod 30 includes at least one locking device 34 for locking the axial position of the piston rod, as will be described in more detail below. In the embodiment of the invention shown in FIG. 2a and 2d, the at least one locking device is in the form of a beveled locking protrusion 34 that may flex radially outward or may be resilient to allow insertion of the proximal end of the piston rod into an internal volume or chamber 37 formed by the locking portion of the piston rod 30 below the locking protrusion 34 having a beveled edge.

Preferably, a plurality of locking devices 34, such as the locking protrusions mentioned above, are arranged circumferentially at equal distances from each other in the locking portion of the piston rod 30, thereby defining an internal volume or receiving space for receiving and fixing the axial position of the piston rod at its most forward position. axial position (or at a position close to the extreme forward axial position) of the piston rod in the syringe barrel.

As best shown in FIG. 2a and 2d, the piston rod locking device 30 may be formed by a cylindrical side wall 31 with at least one locking projection 34 integrally formed with the inner surface of the cylindrical side wall 31, such that the internal volume or receiving space 37 for fixing the axial position of the rod The piston is defined between the lower side 36 of at least one locking protrusion 34 and the annular lower part 32 of the locking part of the piston rod 30. In this case, the annular lower part 32 acts as a stop surface for establishing the extreme forward axial position of the piston rod in the syringe barrel due to the stop having the disc-shaped proximal end of the piston rod into the thrust surface 32. This means that the width of the connecting channel 29 under the annular bottom portion 32 is less than the width or diameter of the disc-shaped proximal end 50 of the piston rod 5 (see FIG. 4a).

However, in accordance with other embodiments of the inventions (not shown), in order to establish the forwardmost axial position of the piston rod in the syringe barrel, this stop function can also be realized by means of projections projecting into the chamber or receiving space 37 of the locking portion of the piston rod 30 in position under the locking projections 34 to limit further movement (indentation) of the disc-shaped proximal end of the piston rod, thereby defining the extreme forward axial position of the piston rod in the syringe barrel by resting the disc-shaped proximal end of the piston rod against such projections.

If the disc-shaped proximal end of the piston rod is firmly locked by at least one locking projection 34, as shown in FIG. 6b and described below, the disc-shaped proximal end of the piston rod is located entirely within a chamber or receiving space 37 defined by the cylindrical side wall 31 of the locking portion of the piston rod 30, particularly formed between the lower sides 36 of the locking protrusions 34 and the thrust surface 32. In such a locked state, as shown in FIG. 6b, the cylindrical side wall 31 of the locking portion of the piston rod 30 completely surrounds or covers the proximal end of the piston rod to prevent unauthorized access to the disc-shaped proximal end 50 of the piston rod 5, for example, to prevent removal from the chamber 37 by loosening the tight fit when closing although one blocking protrusion 34 due to bending. Thus, the cylindrical side wall 31 enhances the tamper resistance provided by the at least one hard locking device to prevent unintentional reuse of the syringe after a drug dose is administered by pressing the rod to its most anterior axial position in the syringe. In the locked state, the disc-shaped proximal end 50 of the piston rod 5 is completely contained within the volume or chamber defined by the cylindrical side wall 30, thereby providing a clear and distinct indication that the syringe has been used.

Simultaneously, the locking projections 34 define a specific minimum distance between the proximal side of the disc-shaped proximal end 50 of the piston rod 5 and the upper rim of the cylindrical side wall 31 of the locking portion of the piston rod 30, thereby preventing the withdrawal of the disc-shaped proximal end 50 of the piston rod 5 towards the proximal end of the locking rod 50. part of the piston rod 30 beyond this zone, located at a minimum distance, after rigidly locking the axial position of the piston rod 5. As can be concluded from FIG. 6b, this minimum distance corresponds to at least the axial length of the locking lugs 34 and can be greater than this axial length if the locking lugs 34 are located slightly deeper inside the chamber 37 of the piston rod locking device 30.

As best seen in Fig. 2d and 2e, a window or cutout 34a may be formed in the cylindrical sidewall 31 of the locking portion of the piston rod 30 at each position of at least one associated rigid locking device (e.g., locking projection 34) to further assist in deflection of the at least one locking projection 34 in the direction cylindrical side wall 31 when inserting the piston rod. As best seen in Fig. 2c, at least one locking projection 34 may be formed as a rectangular plate projecting at an acute angle radially into the connecting channel 29. At least one locking projection 34 may be connected to the cylindrical side wall 31 only at its upper (proximal) end. , thereby allowing the locking projection 34 to flex properly relative to its upper (proximal) end, serving as a fulcrum when the piston rod is inserted from above into the locking portion of the piston rod 30.

Naturally, the blocking projection 34 can also be formed as a continuous blocking projection with a beveled surface on the inner surface of the cylindrical side wall 31 without forming windows or cutouts 34a.

In FIG. 3 is a cross-sectional view of a piston rod locking device mounted on a barrel flange 13 of a syringe 10 in accordance with a preferred further embodiment of the present invention. According to this embodiment of the invention, the piston rod locking device 2 further provides a so-called stop stop function, which further prevents the piston from being unintentionally withdrawn from the syringe barrel. As shown in FIG. 3, at least one projection 28 may project radially into the tubular connection channel 29, thereby further reducing the cross-sectional width of the connection channel 29 to a width slightly less than the outer diameter of a plunger (not shown) inserted into the barrel of the syringe 10, further assisting in preventing withdrawal piston from the barrel of the syringe 10. At least one projection 28 may be formed by the inner edge 25 of the lower hole 26 having a semicircular shape, but also this projection may be formed as a separate element on the distal surface of the upper plate 20 of the mounting part 20. For example, at least one the projection 28 may be formed as an axial extension of the connecting portion 27 or the mounting portion 20. At least one projection 28 fits snugly into the open proximal end 15 of the barrel of the syringe 10, thereby facilitating rigid fixation of the mounting portion 40 to the flange 13. In the installed state of the locking device , shown in Fig. 3, the intermediate space 23 of the mounting part 40 provides a certain clearance to compensate for the variable diameters of the flange 13.

As best seen in Fig. 2a and 3, the connecting channel 29 extends through the entire locking device 2 in the axial direction, including the locking portion of the piston rod 30 as well as the mounting portion 40, and is generally sized to allow the syringe plunger to be easily inserted therethrough. The connecting channel 29 has a profile corresponding to the base surface of the disc-shaped proximal end of the piston rod, and may have a circular profile in the preferred embodiment, in which the disc-shaped proximal end of the piston rod has a circular base surface. The connecting channel 29 is formed by the internal volume or receiving space 37 of the locking part of the piston rod 30, the internal volume of the connecting part 27 and the internal volume of the mounting part 40. In this embodiment of the invention, the minimum diameter of the connecting channel 29 corresponds to the outer diameter of the piston rod, except for its proximal end, which usually has a disk shape and a size slightly larger than the outer diameter of the piston rod. In the state with the locking device installed shown in FIG. 3, the connecting channel 29 communicates with the internal volume of the barrel of the syringe 10, allowing the piston rod to be inserted into the syringe barrel through the connecting channel 29 and the open proximal end 15. Typically, the piston is inserted into the proximal open end 15 of the barrel of the syringe 10 when the locking device is not yet installed on flange 13. However, in an alternative embodiment of the invention, the plunger can be inserted into the proximal open end 15 of the barrel of the syringe 10 when the locking device is already installed on the flange 13, and when the plunger rod is not yet inserted into the syringe barrel. To achieve this, it is recommended that at least one projection 28 be slightly beveled radially inward and downward and only slightly project radially into the open proximal end 15, as shown in FIG. 3, to ensure slight elastic deformation of the piston when inserted into the barrel of the syringe 10 through the connecting channel 29 and to allow it to expand back as the barrel of the syringe 10 expands for further movement to the distal end of the barrel of the syringe 10 with a sealing contact inside the cylindrical wall of the syringe barrel 10.

As will be apparent to one skilled in the art, the minimum diameter of the connecting passage 29 need not be less than the maximum outer dimension of the piston, since the stop stop function described above to prevent inadvertent removal of the piston from the syringe barrel in accordance with the present invention is an additional function of the locking device.

In FIG. 4a shows the piston rod 5 inserted proximally through the connecting channel 29 into the barrel of the syringe 10 with a locking device in accordance with the present invention mounted on the proximal end of the syringe barrel 10. At this stage, the piston rod is already inserted into the syringe barrel. The piston rod 5 includes a rod 52. As shown in FIG. 4a, the rod 52 may have a plurality of ribs extending along the entire length of the axis of the piston 52 and parallel to the imaginary longitudinal axis of the piston. As shown in FIG. 4a, the ribs can intersect each other, for example, at right angles. The proximal end 50 of the piston rod 5 may be disc-shaped and in this example is formed by a circular disc 50, the outer diameter of which is larger than the outer diameter of the piston rod 52 in all other parts (for example, in the area of these ribs). This outer diameter of the disc-shaped proximal end of the piston rod 5 is less than the inner diameter of the locking portion of the piston rod 30 (in particular, the cylindrical side wall or the receiving volume thereof), but is greater than the clear diameter between the locking projections 34 in the receiving volume chamber 37 of the locking portion of the piston rod. thirty.

At the opposite distal end 51 of the piston rod 5, a screw connection or other type of connection may be provided to connect the piston rod 5 to the piston (not shown in the drawing). Typically, in the state shown in FIG. 4a, the piston is already inserted into the barrel chamber of the syringe 10 to seal the dose of medicine previously introduced into the chamber. Thus, the plunger rod 5 is inserted through the locking device connecting channel 29 and the open proximal end of the syringe barrel 10 to be connected to the plunger by means of a thread 53 or other type of connection provided at the distal end 51 of the plunger rod 5. To enable insertion of the plunger rod 5, an internal the width at the narrowest part of the connecting channel 29, defined for example by the protrusion 28 at the distal end of the connecting part 27 or the truncated (truncated-conical) inner edge 25 (see Figs. 2b and 2d), must be greater than the maximum outer diameter of the piston rod, in particular, at its distal end 51.

In FIG. 4b shows the piston rod 5 inserted into the barrel of the syringe 10 with the locking device shown in section in FIG. 4a, in a state where the distal end 51 of the piston rod 5 is connected to the piston 55 inside the barrel chamber 16 of the syringe 10.

At this stage, the injection of liquid 19 through the injection channel and syringe needle (not shown) can be initiated by pressing the piston rod 5 towards the distal end 11 of the syringe 10 barrel. As a result of pressing, the proximal end 50 of the piston rod 5 reaches the area of the locking part of the piston rod 30 , as shown in Fig. 5a. At this point, the piston 55 is depressed to substantially the most anterior distal position in the barrel of the syringe 10, and the disc-shaped proximal end 50 of the piston rod 5 contacts the beveled face 35 of the locking projections 34. As the piston rod 5 is further pressed toward the distal end 11 of the cylinder of the piston 10, The disc-shaped proximal end 50 begins to move along the beveled edges 35 of the locking protrusions 34, bending the resilient locking protrusions 34 outward toward the cylindrical sidewall of the locking portion of the piston rod 30, and/or deflecting or bending the disc-shaped proximal end 50 of the piston rod 5. How shown in Fig. 5b, the disk-shaped proximal end 50 of the piston rod is ultimately moved beyond the front ends of the beveled edges 35 of the locking protrusions 34 and is fully inserted within the chamber or receiving volume 37 formed by the cylindrical side wall of the locking portion of the piston rod 30. Particularly, the disk-shaped the proximal end 50 of the piston rod moves into the intermediate space formed between the lower edges 36 of the locking projections 34 (see Fig. 2a) and the annular thrust surface 32 at the bottom of the locking portion of the piston rod 30, causing the locking projections 34 to bend back into the connecting channel 29 to return to its original position. In this state, the piston 55 reaches its most forward distal position in the barrel of the syringe 10, as shown in FIG. 5b.

Specifically, in accordance with the present embodiment, the most forward distal position of the piston 55 in the barrel of the syringe 10 is achieved when the distal side of the disc-shaped proximal end 50 abuts the annular stop surface 32 at the bottom of the locking portion of the piston rod 30.

As shown in FIG. 5a and 5b, the height of the chamber or receiving space 37 formed between the lower edges 36 of the locking projections 34 (see FIG. 2a) and the annular thrust surface 32 at the bottom of the locking portion of the piston rod 30 in the axial direction of the locking device may be equal to the thickness of the locking device. disc-shaped proximal end 50 of the piston rod 5 so that the disc-shaped proximal end 50 is tightly inserted between the lower edges 36 of the locking projections 34 (see Fig. 2a) and the thrust surface 32 at the bottom of the locking portion of the piston rod 30 without axial play. In any case, locking the disc-shaped proximal end 50 of the piston rod 5 with the locking projections 34 reliably prevents unauthorized unlocking of the piston rod 5 after injection by removing the disc-shaped proximal end 50 of the piston rod 5 of the chamber or receiving space 37.

In FIG. 6a is a sectional view of the proximal end of the syringe barrel being substantially in the piston rod locking position in accordance with FIG. 5a. In FIG. 6b is a cross-sectional view of the proximal end of the syringe barrel in the piston rod locked position in accordance with FIG. 5b when the disc-shaped end 50 of the piston rod is generally locked without play in the intermediate space between the locking projections 34 and the annular stop surface at the bottom of the chamber or receiving space 37. In such a state, the disc-shaped proximal end 50 is completely contained and held in the chamber or receiving space 37 of the piston rod 30 locking device, and unintentional removal of the piston rod is reliably prevented, which is an anti-tamper indicator to prevent unintentional reuse of the syringe after the disc-shaped proximal end 50 of the piston rod is locked by the locking projections 34.

In FIG. 7a-7e show another embodiment of a locking device in accordance with the present invention. In this embodiment, compared to the above-mentioned first embodiment of the invention, the chamber or receiving space 37 of the blocking portion of the piston rod 30 has a more open, filigree structure, in which in the cylindrical side wall 31 forming the chamber or receiving space 37 of the blocking portion of the piston rod 30, windows 34a having a relatively large size are formed. Specifically, multiple rectangular windows 34a, such as four windows 34a, may be provided around the circumference of the cylindrical side wall 31 at equal distances from each other, with axial connecting ribs provided therebetween to connect the annular upper rim of the cylindrical side wall 31 to the bottom portion 32 blocking portion of the piston rod 30. As shown in FIG. 7a, blocking projections 34 are formed above the corresponding window 34a. As shown in the plan view of FIG. 7b, these locking projections 34 have linear leading edges defining the side edges of an imaginary square whose side length is slightly less than the maximum outer width of the disc-shaped proximal end of the piston rod (not shown) being locked by the locking projections. Also, in this embodiment, the upper surfaces of the locking projections 34 are formed in the form of beveled edges 35 directed inward and downward at an acute angle to the chamber 37 formed by the cylindrical side wall 31. The lower edges 36 of the locking projections 34 may be located perpendicular to the cylindrical side wall 31 , thereby preventing the proximal end of the piston rod from inadvertently unlocking after it has been locked in the intermediate space between the locking projections 34 and the annular lower portion 32 of the locking portion of the piston rod 30.

In FIG. If shows a sectional view of the proximal end of the syringe barrel being substantially in the locking position of the piston rod locking device in accordance with FIG. 7a. In FIG. 7g is a cross-sectional view of the proximal end of the syringe barrel in the locked position of the piston rod locking device in accordance with FIG. 7a when the disc-shaped end 50 of the piston rod is locked with axial play in the intermediate space between the locking projections 34 and the annular thrust surface 32 at the bottom of the chamber or receiving space 37. In the position shown in FIG. 7g, the disc-shaped proximal end 50 is completely contained and held in the chamber or receiving space 37 of the locking portion of the piston rod 30, and unintentional removal of the piston rod by withdrawing the disc-shaped proximal end 50 of the piston rod from the chamber or receiving space 37 is reliably prevented, which is a tamper-proof indicator to prevent unintentional reuse of the syringe after the disc-shaped end 50 of the plunger rod is locked by the locking projections 34. At the same time, the disc-shaped end 50 and the plunger rod 5 can be moved axially within a certain short distance because the axial length disc-shaped end 50 is less than the distance between the lower edges 36 of the locking projections 34 and the stop surface 32 at the bottom of the chamber 37.

When the piston rod 5 is further pressed towards the distal end 11 of the cylinder of the piston 10 from the position shown in FIG. 7f, the disc-shaped proximal end 50 begins to move along the beveled edges 35 of the locking protrusions 34, bending the resilient locking protrusions 34 outward toward the cylindrical side wall 31 of the locking portion of the piston rod 30, and/or deflecting or bending the disc-shaped proximal end 50 of the rod. piston 5. As shown in FIG. 7g, the disk-shaped proximal end 50 of the piston rod is ultimately moved beyond the front ends of the bevels 35 of the locking protrusions 34, and is completely contained within the chamber or receiving space 37 formed by the cylindrical side wall 31 of the locking portion of the piston rod 30. In particular, the disk-shaped the proximal end 50 of the piston rod is moved into a chamber or receiving space 37 formed between the lower edges 36 of the locking projections 34 and the annular thrust surface 32 at the bottom of the locking portion of the piston rod 30, such that the locking projections 34 are bent back into the connecting channel 29 to return to its starting position. In the state shown in FIG. 7g and 7i, when the disc-shaped proximal end 50 of the plunger rod abuts the annular stop surface 32 at the bottom of the chamber 37, the plunger 55 will reach its most anterior distal position in the barrel of the syringe 10, as shown in FIG. 7i.

In this embodiment, the upper rim of the side wall 31 above the ports 34a may be relatively thin and may form a relatively thin resilient cylindrical rib extending along the side wall 31 which further assists in proper flexion of the locking projections 34 as the proximal end of the piston rod moves over the locking projections. 34.

In FIG. 8a-8c show another embodiment of the locking device in accordance with the present invention, in which the chamber 37 of the locking portion of the piston rod 30 has a more open, filigree design, in which the chamber 37 is mainly formed by two annular ribs: one annular ridge 39a, forming the upper rim of the locking portion of the piston rod 30, and another annular rib formed in this example by the annular thrust surface 32 at the bottom of the locking portion of the piston rod 30. In accordance with another embodiment of the invention (not shown) at the lower end of the chamber 37 and above the annular thrust surface 32, a second annular rib similar to the annular rib 31 may be provided at the bottom of the blocking portion of the piston rod 30.

As shown in FIG. 8a, the upper annular rib 39a and the lower portion 32 of the locking portion of the piston rod 30 are connected to each other by several axial connecting ribs 39b, which may be relatively thin, and the windows 34a between these axial connecting ribs 39b may be relatively wide. With respect to this embodiment of the invention, it can be said that the chamber or receiving volume 37 of the blocking portion of the piston rod 30 is formed in the form of a sleeve with relatively wide windows 34a. However, once locked by the locking projections 34 within the chamber or receiving space 37, the disc-shaped proximal end of the piston rod remains covered by the axial connecting ribs 39b and the upper annular rib 39a sufficiently to prevent unwanted manipulation of the disc-shaped proximal end of the piston rod and resulting in the inadvertent release of the locking projections 34 so that the disc-shaped proximal end of the piston rod remains securely locked and held within the chamber or receiving space 37 of the locking portion of the piston rod 30. To this end, the windows 34a may be of a width that precludes access to the shaped disc to the proximal end of the piston rod on the outside of the chamber or receiving space 37 or sleeve, for example, to prevent the tip of the user's little finger from touching the outside of the proximal end of the piston rod.

As shown in FIG. 8a, blocking projections 34 are formed above a corresponding window 34a on the inner side of the annular rib 39a. As shown in the plan view of FIG. 8b, these locking projections 34 may have a convex leading edge projecting into the interior of the chamber 37 of the piston rod locking device 30. A convex 39 c may be provided at the rear of each locking projection 34, which, on the one hand, may further facilitate proper bending of the annular ribs 39b as the disc-shaped proximal end of the piston rod moves over the chamfered top surfaces of the locking ridges 34 when inserted into the chamber 37 and, on the other hand, may further contribute to the generation of a return force returning the locking ridges 34 and annular ridge 39a back to the unstressed original position , shown in Fig. 8b, after the proximal end of the piston rod has been fully inserted into the chamber or receiving volume 37 of the sleeve-shaped structure. Also, in this embodiment, the upper surfaces of the locking protrusions 34 are formed as beveled edges 35 directed inward and downward at an acute angle to the chamber or receiving space 37, in which the lower edges 36 of the locking protrusions 34 may be parallel to the thrust surface 32 at the bottom. chamber or receiving space 37, thereby preventing the proximal end of the piston rod from being unintentionally released after being locked in the chamber or receiving space 37 formed between the locking projections 34 and the annular lower portion 32 of the locking portion of the piston rod 30.

For all of the above embodiments, the height of the chamber or receiving volume 37 formed between the lower edges 36 of the locking projections 34 and the abutment surface 32 at the bottom of the locking portion of the piston rod 30 in the axial direction of the locking device may be slightly greater than the thickness of the disk-shaped proximal end 50 piston rod 5 so that the disc-shaped proximal end 50 is located between the lower edges 36 of the locking projections 34 and the thrust surface 32 at the bottom of the locking portion of the piston rod 30 with a certain axial clearance. Thus, the piston rod 5 is not effectively blocked without axial play by the blocking portion of the piston rod 30. More precisely, the residual dose of liquid can be administered by pressing the piston rod 5 towards the distal end 11 of the barrel of the syringe 10 after the disc-shaped proximal end 50 has moved beyond locking projections 34 to a position where the disc-shaped proximal end 50 ultimately abuts the abutment surface 32 of the locking portion of the piston rod 30 defining the forwardmost axial position of the piston 55.

When comparing the cross-sectional views in FIG. 6a/6b and 7f/7g, it will be apparent to one skilled in the art that the locking device in accordance with the present invention can generally be provided without the above-mentioned stop function to prevent the piston from being inadvertently removed from the syringe barrel after the locking device has been installed on the flange. at the open proximal end of the syringe barrel. This stop stop function is implemented in the embodiment of the invention shown in FIG. 6a and 6b by means of projections 28 which narrow the connecting channel 29 so that its width becomes less than the diameter or width of the piston (not shown). On the other hand, in the embodiment of the invention shown in FIG. 4f and 7g, the projections 28 generally do not narrow the connecting channel 29 formed in the locking device.

Although the disc-shaped proximal end of the piston rod is depicted in the drawings as having a circular base, one skilled in the art will appreciate that the disc-shaped proximal end of the piston rod can have a variety of shapes, such as rectangular, square, hexagonal, ovoid, or elliptical. form. Although the figure shows that the proximal end of the piston rod is made of solid material, those skilled in the art will appreciate that the proximal end of the piston rod may be partially hollow or interrupted by channels or through holes or chambers that may be positioned and configured in a manner that will cause the disc-shaped proximal end of the piston rod to sag and flex as it moves along the bevels on the upper surfaces of the locking projections of the piston rod locking device.

Although in the drawings the proximal end of the piston rod is depicted in the form of a disk, one skilled in the art will understand that the proximal end of the piston rod can have any suitable shape, as is known from the prior art, in which case at least one rigid device The interlocking locking portion of the piston rod may be of distinct form and function and may reliably engage other parts at or adjacent to the proximal end of the piston rod in a manner similar to that described above.

As shown in FIG. 9, the proximal end 50 of the piston rod may have an axial step 50a such that a circumferential radial projection 50b is formed at the bottom of the proximal end 50 of the piston rod locked by at least one locking projection of the locking portion of the piston rod, wherein the axial step 50a may extend to the upper rim of the piston rod locking portion, which further facilitates the entry of the proximal end 50 of the piston rod into the piston rod locking portion in its locked position and more reliably prevents inadvertent removal of the piston rod.

One skilled in the art will appreciate that a plunger rod locking device with a stop stop function according to the present invention provides the functions of a stop stop device to prevent the piston from being unintentionally removed from a syringe, as well as the functions of a plunger rod locking device with control function for locking the plunger rod at the proximal end of the syringe after administering a dose of the drug by pressing the piston rod all the way and to prevent reuse of the syringe. One skilled in the art will appreciate that the piston rod locking device with a stop stop function according to the present invention can be manufactured integrally using one of the conventional methods, such as injection molding. The device may be made of suitable medical grade plastics, hard rubber materials, glass, metals, etc.

One skilled in the art will appreciate that the plunger rod locking device with the stop stop function of the present invention can be placed on the syringe flange regardless of the presence or absence of a plunger.

While descriptions of preferred embodiments of the present invention have been presented in order to enable the present invention to be practiced by those skilled in the art, it is understood that changes and modifications may be made without any departure from the concept and purpose of the present invention as described in the appended claims. Accordingly, the above description is exemplary and should not be used to limit the scope of the invention. The scope of the invention is to be determined only by reference to the appended claims.

List of specified item numbers

1 syringe

2 piston rod locking device

3 syringe with piston rod locking device 2

5 piston rod

10 cylindrical syringe body

11 distal end

12 injection channel

13 flange / finger support

14 rounded inner flange edge 13

15 open proximal end

16 internal volume/chamber

19 liquid

20 top plate

21 bottom plates

22 side wall

23 intermediate space

24 rounded locking edge

25 semicircular inner edge

25a guide edge

26 hole

27 connecting part

28 blocking lug

29 connecting channel

30 piston rod blocking element

31 cylindrical sidewall

32 thrust surface

33 proximal edge

34 blocking projection 34a window

35 beveled edge of locking lug 34

36 lower edge of blocking protrusion 34

37 chamber / receiving space

38 gap

39a annular rib

39b axial connecting rib

39c bulge

40 installation device

50 proximal end of piston rod 5

50a axial stage

50b radial projection

51 distal end

52 rod

53 thread

55 piston

Claims (38)

1. Locking device to lock the plunger rod (5) of the syringe after use and to prevent the syringe from being used again, while the syringe includes a cylinder (10) having an open proximal end (15) and a flange (13) provided adjacent said open proximal end (15), wherein the cylinder (10) is configured to receive a piston rod (5) through said the proximal end (15) is open, and the proximal end (50) of the piston rod (5) is disc-shaped, the specified locking device contains a mounting portion (40) configured to allow the locking device (2) to be mounted on a flange (13) adjacent to said proximal end (15) of the cylinder (10) in a form-fitting manner by pressing the mounting portion (40) against the flange (13) in the direction , perpendicular to the longitudinal direction of the cylinder (10), and snapping the mounting part (40) onto the flange (13), and blocking part of the piston rod (30) to fix the axial position of the piston rod (5) after using the syringe, while in the locking device (2), a connecting channel (29) is formed, allowing the piston rod (5) to be inserted into the open proximal end (15) of the cylinder (10) through the locking part of the piston rod (30) and the installation part (40), while the width of the connecting channel (29) is greater within the locking portion of the plunger rod (30) to form a chamber (37) for receiving the disc-shaped proximal end (50) of the plunger rod (5) after use of the syringe, wherein the locking portion of the piston rod (30) includes rigid locking devices (34) configured to rigidly lock the axial position of the piston rod (5) by accurately locking into the disc-shaped proximal end (50) of the piston rod (5) to lock the rod the piston (5) in the forwardmost axial position (or a position close to the forwardmost axial position) of the distal end (51, 53) of the piston rod (5) in the barrel (10) after use of the syringe, and the locking portion of the piston rod (30) is formed as a cylindrical sleeve-like member formed by two annular ribs (39a) connected to each other by axial connecting ribs (39b), wherein on the inner side of the annular rib (39a) or the axial connecting rib (39b) ) at least one hard locking device (34) is provided. 2. The locking device according to claim 1, wherein a stop surface (32) is provided at the bottom of said chamber (37) for establishing the extreme forward axial position of the distal end of the piston rod (5) in the cylinder (10) by means of a stop of the disc-shaped proximal end (50) of the piston rod (5) into this thrust surface (32). 3. The locking device of claim 1 or 2, wherein each rigid locking device (34) is configured to retain the disc-shaped proximal end (50) of the piston rod (5) within the chamber (37) and prevent removal of the disc-shaped proximal end (50). end (50) of the piston rod (5) towards the proximal end of the locking portion of the piston rod (30) beyond the minimum distance from the proximal upper rim of the locking portion of the piston rod (30) when the axial position of the piston rod (5) is firmly fixed , with the minimum distance corresponding to at least the axial length of the rigid locking device (34). 4. The locking device as claimed in any one of the preceding claims, wherein the chamber (37) formed by the locking portion of the piston rod (30) is configured to prevent complete access to the disc-shaped proximal end (50) of the piston rod (5) from the outside of the locking portion piston rod (30) to prevent the disc-shaped proximal end (50) of the piston rod (5) from being removed from the chamber (37) after the axial position of the piston rod (5) is firmly fixed. 5. The locking device as set forth in any one of the preceding paragraphs, wherein the locking portion of the piston rod (30) is formed integrally with the mounting portion (40). 6. The locking device of claim 5, wherein each rigid locking device is formed into a locking lip (34) that extends radially into the locking portion of the piston rod (30) and is configured to engage with a precise fit when locked. with a disc-shaped proximal end (50) of the piston rod (5). 7. The locking device of claim 6, wherein each locking lip (34) is configured to be elastically deformed or deflected when the disk-shaped proximal end (50) of the piston rod (5) is pressed past the locking lip (34) to a position at which the distal end (51, 53) of the piston rod (5) reaches its most forward axial position in the cylinder (10). 8. The locking device according to claim 6 or 7, wherein each locking projection (34) is formed at a window (34a) which is formed in the locking portion of the piston rod (30) so that the chamber (37) communicates with an area located outside the locking parts of the piston rod (30). 9. Locking device according to any one of paragraphs. 6-8, in which each locking protrusion (34) has a beveled upper edge directed towards the proximal open end of the locking portion of the piston rod (30), and a lower edge (35) projecting radially into the chamber (37) formed by the locking portion piston rod (30). 10. The locking device as claimed in any one of the preceding claims, wherein the height of the chamber (37) formed by the locking portion of the piston rod (30) in the axial direction of the device is equal to the thickness of the disc-shaped proximal end (50) of the piston rod (5); or greater than the thickness of the disc-shaped proximal end (50) of the piston rod (5). 11. The locking device according to any one of the previous paragraphs, in which the mounting part (40) includes an upper plate (20) directed towards the proximal end of the connecting channel (29), and a lower plate (21) opposite to said upper plate (20), intermediate space (23) formed by the upper and lower plates (20, 21), while at the proximal end of the mounting part (40) at least one protrusion (25) is formed, protruding from the upper plate (20) into the intermediate space (23) and having a configuration that provides precise fit engagement with the open proximal end (15) of the cylinder (10) for mounting the locking device (2) on the flange (13) of the cylinder (10). 12. The locking device according to claim 11, wherein at least the lower end on at least one projection (25, 28) facing the lower plate (21) of the mounting part (40) is elastic. 13. Locking device according to claim 11 or 12, in which at least one protrusion has a conical profile, the outer diameter of which corresponds to the inner diameter of the cylinder (10) at the open proximal end (15), while the height of the intermediate space (23) formed between the upper and lower plates (20, 21) of the mounting part (40), preferably corresponding to the height of the flange (13) at the open proximal end (15) of the cylinder (10). 14. The locking device according to any of the previous paragraphs additionally consists of at least one protrusion (25, 28) provided in the connecting channel (29), narrowing the connecting channel (29) in sections to a width less than the outer diameter of the piston (55), used to seal the cylinder (10), to prevent inadvertent removal of the piston (55) from the cylinder (10) through the connecting channel (29). 15. Syringe assembly containing: a syringe barrel (10) having a distal end (11), an open proximal end (15) opposite the distal end (11), a side wall between the distal end and the open proximal end, a forming chamber (16) and a flange (13) provided adjacent with said open proximal end (15); a piston (55) located inside the chamber (16) of the syringe barrel (10); a piston rod (5) associated with a piston (55) and connected to a piston having the shape of a disk of the proximal end (50) of the piston rod (5); And a locking device (2) mounted on a flange (13) adjacent to said proximal end (15) by engaging with a precise locking fit to lock the piston rod (5) in its forwardmost axial position (or position close to its forwardmost axial position) position) of the distal end (51, 53) of the piston rod (5) in the cylinder (10) after using the syringe and to prevent reuse of the syringe; wherein the specified locking device contains a mounting portion (40) for mounting a locking device (2) on a flange (13) adjacent to said proximal end (15) by engaging with a precise fit when locked by pressing the mounting portion (40) against the flange (13) in a direction perpendicular to the longitudinal direction of the cylinder (10), and snapping the mounting part (40) onto the flange (13), and blocking part of the piston rod (30) to fix the axial position of the piston rod (5) after using the syringe, while in the locking device (2), a connecting channel (29) is formed, allowing the piston rod (5) to be inserted into the open proximal end (15) of the cylinder (10) through the locking part of the piston rod (30) and the installation part (40); wherein the width of the connecting channel (29) is greater inside the locking portion of the piston rod (30) to form a chamber (37) to receive the disc-shaped proximal end (50) of the piston rod (5) after using the syringe, the locking portion of the piston rod (30) includes rigid locking devices (34) configured to rigidly lock the axial position of the piston rod (5) by engaging in a precise locking fit with the disc-shaped proximal end (50) of the piston rod (5) to locking the plunger rod (5) in the forwardmost axial position (or a position close to the forwardmost axial position) of the distal end (51, 53) of the plunger rod (5) in the barrel (10) after using the syringe, and the locking portion of the piston rod (30) is formed as a cylindrical sleeve-like member formed by two annular ribs (39a) connected to each other by axial connecting ribs (39b), wherein on the inner side of the annular rib (39a) or the axial connecting rib (39b) ) at least one hard locking device (34) is provided. 16. The syringe assembly of claim 15, wherein the chamber (37) formed by the locking portion of the plunger rod (30) is configured to prevent full access to the disc-shaped proximal end (50) of the plunger rod (5) located outside the locking portion. piston rod (30) to prevent the disc-shaped proximal end (50) of the piston rod (5) from being removed from the chamber (37) after the axial position of the piston rod (5) is firmly fixed. 17. The syringe assembly according to claim 15, wherein the locking portion of the piston rod (30) is formed integrally with the mounting portion (40). 18. The syringe assembly of claim 15, wherein each rigid locking device is formed in the form of a locking lip (34) that extends radially into the locking portion of the piston rod (30) and is configured to ensure an accurate fit when engaged with the disc-shaped proximal end (50) of the piston rod (5). 19. The syringe assembly of claim 18, wherein each locking projection (34) is configured to be elastically deformed or deflected when the disc-shaped proximal end (50) of the piston rod (5) is pressed past the locking projection (34) to a position , at which the distal end (51, 53) of the piston rod (5) reaches its most forward axial position in the cylinder (10).

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