WO1990007948A1

WO1990007948A1 - Single use hypodermic syringe

Info

Publication number: WO1990007948A1
Application number: PCT/ES1990/000002
Authority: WO
Inventors: Jaime Caralt Batlle
Original assignee: Jaime Caralt Batlle
Priority date: 1989-01-19
Filing date: 1990-01-18
Publication date: 1990-07-26
Also published as: AU4959690A; ES2011414A6

Abstract

The disclosed syringe is comprised of a hollow plunger (5) with which a hollow pusher (4) is integral, and to which is fixed, before and during its first use, a core (6) which tends to be driven towards the inside of the pusher (4) by means of a spring (8), core (6) whose internal end is prolonged by a short stem traversing a central obturator (18) surrounded by another annular obturator (17) integral with the plunger (5), the stem being topped by an interlocking head (19) with which a bushing (29) is complementary, said bushing being provided in the neck (27) of the needle (28), and sliding on the floating support (23) for a seat (21) of the obturator so that, after applying the injection and total emptying of the chamber (20), the head (19) interlocks with the bushing (29), and the core (6) is released and its retraction drives the needle (28) towards an inaccessibility situation within the body (1).

Description

Title: "HYPODERMIC SYRINGE OF A SINGLE USE" Technical field.-

The present invention refers to a single-use hypodermic syringe, of the type that, after use, becomes unusable, comprising a tube, with its front part narrowed and adapted to receive a hypodermic needle, and a sliding plunger inside. of the tube.

State of the art.- The use of single-use hypodermic syringes, which are marketed in sterile, hermetically sealed containers that are broken at the time of use of the syringe, is already well known, being discarded after its unique use.

However, although such syringes are built and marketed to be used only once, the reality is that their structural characteristics allow them to be reused without any problem from a mechanical point of view, but with obvious and very serious problems from the sanitary point of view.

These problems have recently worsened after the onset of AIDS disease, which eventually causes the death of the patient and which is not yet known a medication for cure or a vaccine that prevents its spread. Although many single-use syringe embodiments have been carried out to avoid the subsequent reuse of the syringes, none of them achieves the automatic and without subsequent danger of voluntary or involuntary injuries caused by the needle after only use of it.

Some of the known embodiments are based on an alleged breakage, bending or partial destruction of the syringe or needle, but in them the plastic nature of the syringe body prevents its destruction, and although trying to avoid the aforementioned reuse proceed to the bending of the needle, the mental situation in which a certain type of users are normally found, specifically the drug addicts, who are often subjected to a situation of extreme anxiety, makes this practice totally unsuccessful, since that for example the needle can be straightened to a greater or lesser extent and this eliminates an obstacle to the reuse of the syringe.

Description of the invention.-

The single-use syringe object of the invention has been designed to solve this problem to full satisfaction, ensuring that the only intended use is necessary and irremediably in practice, and for that purpose said syringe It focuses its characteristics on a special structuring, thanks to which and at the end of the use of the same, the needle is collected towards the inside of the syringe body, where it adopts a stable positioning of absolute inaccessibility, being necessary to destroy the body itself of the syringe to access the needle, which obviously makes the assembly useless.

In its essence, the single syringe in question in the present invention is characterized in that in the inner front part of the tube there are disposed sealing means traversed and held in operative position by the needle head, said head being in turn the needle subjected to the action of elastic means, which tend to push it towards the inside of the tube, and retained by means of retention integral with the inner front part of the tube, said piston being provided with an internal axial cavity, whose only mouth , arranged at the front end of the plunger, is closed by a closure element of the recess provided with irreversible coupling means with other complementary coupling means arranged in the needle head and intended to collaborate by contacting each other at the end of the operational stroke of the plunger, all arranged so that when the latter reaches the end of said operational stroke, The above means of irreversible coupling of the closing element of the plunger cavity with said complementary coupling means arranged in the needle head, so that the closing element is irreversibly associated with the needle head, pushing the plunger into its advance to the sealing means a short section forward and acting through them on the retaining means of the needle head, so that it is released, then acting said elastic means, which push the needle and the element of closure irreversibly associated with it to the inside of the plunger cavity.

According to another characteristic of an embodiment of the invention, a corresponding pusher, also hollow, fitted in its cavity with a core, fixed to the plunger is fitted in the hollow of the plunger with the aid of a bush provided with wide longitudinal cuts, which they allow a radial deformability of the same, the cap being provided with a slight internal perimeter throat in which an equally perimeter shoulder of the core is coupled, permanently tending to be projected towards the free end of the pusher by effect of a spring that relates it with the bottom of said pusher and working in contraction, being stationary in the internal front of the piston and the core two complementary shutters, the corresponding shutter being to the core centered on a neck, which is the axial extension of said core and is topped by an interlocking head.

According to another characteristic of a second embodiment of the invention, said sealing means are constituted by a discoidal piece of a slightly flexible material, which by its edge is in contact with the inner wall of the front part of the tube and performs with this one a hermetic seal, and which is provided with a countersunk central hole to receive the end of the head of the needle that passes through it, also carrying out with said end a hermetic closure, said disk piece being also provided on its front face with some Appendices adapted to act on the integral retention means of the inner front part of the tube, when the disk piece is pushed by the front end of the piston when it reaches the end of its operational stroke, so that the disk piece, and with it the needle moves a short section forward under the thrust of the plunger and the aforementioned appendages in turn push the aforementioned retention means, thus releasing the needle which, subject to the action of the spring, is forced into the cavity of the plunger.

Brief description of the drawings.-

Other features and advantages of the syringe Hypodermic object of the present invention, will follow from the description that follows in relation to the attached drawings, which illustrate, by way of non-limiting example, two embodiments of the invention.

Fig. 1 is a sectional elevational view, in use position, of a first embodiment of the syringe of the invention;

Fig. 2 illustrates a view analogous to that of Fig. 1 of a second embodiment of the syringe of the invention; Y

the Fig. 3 shows a view of the syringe of Fig. 1, but in the position where it is unusable.

The attached drawings illustrate a first embodiment, in which it can be seen that the single-use hydrodermic syringe in question is constituted from a tube 1, similar to that of any conventional syringe and with its classic eyelashes or fins 2 in its mouth, which facilitate its manipulation during the injection, specifically supporting the index and ring fingers on them, while the thumb is supported, at the end 3 of the classic rod or pusher 4, to which the corresponding piston is integral 5, but with the particularity that in the present case the aforementioned plunger 5 is hollow, as is the pusher 4, and inside these elements a core 6 is provided provided at its inner end with a hitch 7 for a spring 8 that works under tension, which at its other end is fixed to the hitch 9 of the free end of the pusher and which obviously tends to retract the core 6 towards the hollow interior of the repeatedly mentioned pusher 4.

The core 6 is provided with a small perimeter flange 10, which fits into the complementary groove of a bush 11 established between the core 6 and the plunger 5 and provided with a certain radial deformation, thanks to the existence of deep cuts 12 existing in the same, finishing off this cap 11 in a perimeter tooth 13, through which it is locked in a perimeter throat and complementary to the mouth of the pusher 4, mouth on which also acts a small spring 14 that works under compression and that by its other end is supported by an internal step 15 of the piston 5 itself.

To the piston 5, by means of the perimetric tongue and groove 16 or by any other appropriate means, an annular plug 17 is fixed, which is complemented by a central sector 18, which in turn is integral with the core 6, specifically with an axial extension rod of the latter. and finished off in an interlocking head 19, so that elements 17 and 18 determine the movable wall of a chamber 20 in which the product to be injected is to be lodged and towards which it emerges lightly mind the aforementioned head of interlocking 19.

Complementarily and at the bottom of the tube 1, complementing the aforementioned product chamber 20, the seat 21 for the shutter 17 is established, a seat that also adopts an annular configuration, which by means of another perimetral tongue and groove 22, is integral with a floating support 23 and which rests on the closed bottom 24 of the tube 1, through a robust spring 24 that works under compression, a perimeter step 26 of the tube 1 acting as a travel limiter for said seat 21 of the shutter.

Both the seat 21 and the floating support 23, are axially traversed by the neck 27 of the needle 28, which emerges outwardly centered and through the base 24 of the tube 1, said neck 27 incorporating a nozzle 29 in its extremity in the that the head 19 of the core 6 is susceptible to pressure laundering, this neck 27 being also assisted by a bushing 30 also provided with deep cuts 31, which allow its radial deformability, bushing that similarly is fixed to another core 32, of coining, with a conical front 33 complementary to a similar facet, established at the bottom 24 of the tube 1 and against which said core 32 is projected by another small spring 34 established between the front of the core 32, and an internal perimeter scaling of the floating support 23. As a complement to the described structure and in order to facilitate the axial displacements of the floating support 23 against the spring 25, an annular throat 34 is established in said support as a guide for a cylindrical and hollow neck 36 emerging from the base 24 of the body 1, or in said floating support 23 blind holes parallel to its axis are established, in which respective emerging rods of the bottom of body 1 play.

As previously stated and from the situation shown in Fig. 1, the syringe is usable as any conventional syringe, acting on the pusher 4 for filling the chamber 20 with the medicated product in question, and its subsequent injection into the patient, after nailing the needle 1 and until the total cancellation of the volume of said chamber 20.

However, and after said total emptying limit situation, the pressure supplied to the pusher 4 determines the tongue and groove coupling between the coupling head 19 and the nozzle 29, interlocking which is already immovable and irreversible, and during which the support 23 yields by the pressure against the spring 25 and forces the core 33 to strangle over the neck 27 of the needle, immobilizing the latter. At the same time, the unlocking of bushings 11 and 30 occurs, due to the decoupling of tongue and groove elements 10, whereby the core 6 is released, it is abruptly dragged by the spring 8 into the pusher 4, in turn dragging the neck 27 and the corresponding needle 28 associated therewith, which thus passes to stay inside the syringe tube 1, in a situation of absolute inaccessibility, both total and partial.

The embodiment depicted in Figs. 2 and 3 is much more simplified and, as can be seen in the drawings, it comprises a tube 41, with its front part 42, narrowed and adapted to receive a hydrodermal needle 43, and a plunger 44 sliding down the inside of the tube 41.

In the inner front part of the tube 41, sealing means are disposed through and held in operative position by the head 45 of the needle 43.

Said head 45 is subjected to the action of a spring 46, preferably constituted by a helical compression spring, which tends to push it into the interior of the tube 41, and is retained by a sooidal retention means of the inner front part of the tube 41 .

At the front end of the piston 44 there is arranged a closure element of the recess 51 thereof, provided with irreversible coupling means with other complementary coupling means arranged in the head 45 of the needle 43.

Said sealing means are constituted by a discoidal piece 47 of slightly flexible material, which by its edge is in contact with the inner wall of the front part of the tube 41 and performs with it a hermetic seal.

The discoidal piece 47 is provided with a central hole 48, countersunk to receive the conical end 49 of the head 45 of the needle 43 which passes through it, also making said conical end 49 a hermetic seal.

The disk piece 47 is also provided on its front face with some appendages 50, adapted to act on the retaining means integral with the inner front part of the tube 41, when the disk piece 47 is pushed by the front end of the piston 44, to the reach this one at the end of his operational career.

At that time, the disk piece 47, and with it the needle 43, moves forward a short section under the thrust of the piston 44, in turn pushing the aforementioned appendices 50 to the said retention means, whereby the needle 43 is released and, being subjected to the action of the spring 46, is forced by it to be introduced into the recess 51 of the piston 44.

The aforementioned means of retention integral to the front part of the tube 41, are constituted by a plurality of flexible tabs 52, which are born from the wall of the tube 41 and are obliquely directed forward and inward, being adapted to fit inside a peripheral annular groove 53 practiced outside the head 45 of the needle 43, from where they are extracted by bending when pushed by the appendages 50 of the said disk piece 47 of said seal.

Said closing element of the recess 51 of the plunger 44, is constituted by a discoidal button 54, snapped by its edge in the annular groove 55 made in the mouth of said recess 51.

Said button 54 is provided with a protruding protrusion 56, which constitutes said first irreversible coupling means and which is provided with a peripheral step 57 intended to be introduced under pressure in the countersunk hole 58 of the head 45 of the needle 43, of the which is unable to exit by the opposing action of the said second complementary coupling means, constituted in turn by an incoming step.

In the mouth of the recess of the tube 41, there are arranged means for retaining the piston 44, preferably constituted by ribs found 59 and 60, which make it impossible to completely extract it from the inside of the tube 41.

Describe the nature of the invention sufficiently To this, as well as the way to put it into practice, it is stated that everything that does not alter, change or modify its fundamental principle may be subject to variations in detail.

Claims

1.- Single-use hypodermic syringe, of the type that, after use, becomes unusable, comprising a tube, with its front part narrowed and adapted to receive a hydrodermic needle, and a sliding plunger inside the tube, characterized because in the inner front part of the tube there are disposed sealing means traversed and held in operative position by the needle head, said needle head being in turn subjected to the action of elastic means, which tend to push it towards the inside the tube, and retained by means of retention integral with the inner front part of the tube, said piston being provided with an internal axial cavity, whose only mouthpiece, arranged at the front end of the plunger, is closed by a closing element of the cavity provided with first irreversible coupling means with complementary second coupling means arranged at the head of the needle and intended to collaborate with the first coupling means when contacting each other at the end of the piston operational stroke, all arranged so that when the latter reaches the end of said operational stroke, the aforementioned collaborate first means irreversible coupling of the closing element of the plunger cavity with said second complementary coupling means arranged in the needle head, so that the closing element is irreversibly associated with the head of the needle, pushing the plunger into its advance to the sealing means a short section forward and acting through them on the retaining means of the needle head, so that it is released, then acting said elastic means, which push the needle and the element of closure irreversibly associated with it to the inside of the plunger cavity.

2. Hypodermic syringe according to claim 1, characterized in that a corresponding pusher, also hollow, fitted in its cavity with a core, fixed to the plunger is fitted in the hollow of the piston with the help of a bushing provided with large longitudinal cuts, which they allow a radial deformability thereof, the bushing being provided with a slight internal perimeter throat in which an equally perimetral shoulder of the core is coupled, permanently tending to be projected towards the free end of the pusher by the effect of a spring that relates it with the bottom of said pusher and working in contraction, being fixed on the internal front of the piston and the core two complementary shutters, the shutter being corresponding tooth to the nucleus crossed centrally by a neck, which is the axial extension of said core and which is topped by an interlocking head.

3. Syringe according to claims 1 and 2, characterized in that with the shutters collaborates, for the conformation of the container chamber of the product to be injected, a seat which in turn is integral with a floating support, which rests on the closed bottom of the tube with interposition of a spring that works under compression, the seat and its support being crossed axially by a neck to which the needle would be fixed, said neck being finished off by its internal end in an interlocking nozzle, complementary to the head of the core and which receives and fixes the latter, by simple pressure, at the end of the axial travel phase of the plunger, a second bush, similar to the first bushing, provided with cuts between the needle neck and the floating seat support being arranged analogous and fixed in the same way to the mentioned neck.

4. Syringe according to claims 1 to 3, characterized in that the first bushing is provided at its outer end with a perimeter tooth, through which it fits into an internal perimeter throat of the pusher, while entering the corresponding end of said pusher and the internal stepping of the plunger, there is a small spring that locks jaa compression.

5. Syringe according to claims 1 to 4, characterized in that the second bushing that guides and retains the neck of the needle, is in turn provided with a perimeter tooth in its outer mouth, for its coupling in an equally perimeter throat of another mobile core, between whose inner limb and an internal perimeter step of the floating support, is arranged another small spring that works under compression, while its free end is provided with a conical front for wedging said cap on the neck of the needle .

6. Syringe according to claims 1 to 5, characterized in that the tube is provided with an internal perimeter step in functions of a travel limit stop for the shutter seat, at the same time as the pivoting support of said seat is provided with a guiding annular throat on an emerging annular partition of the base of the tube.

7. Single-use hypodermic syringe according to claim 1, characterized in that said sealing means are constituted by a discoid piece of a slightly flexible material, which by its edge is in contact with the inner wall of the front part of the tube and makes a seal with it, and is equipped with a countersunk central hole to receive the end of the head of the needle that passes through it, also making a sealed seal with said end, said disk also being provided on its front face with appendages adapted to act on the retaining means integral with the inner front part of the tube, when the disk piece is pushed by the front end of the piston when it reaches the end of its operational career, so that the discoidal piece, and with it the needle, moves forward a short section under the thrust of the piston and the aforementioned appendages push in turn to the said retention means, thus releasing the needle which, subject to the action of the elastic means, is forced into the cavity of the plunger.

8. A single-use hydrodermic syringe according to claims 1 and 7, characterized in that said said means of retention of the anterior part of the tube are constituted by a plurality of flexible tongues, which are born from the tube wall and are directed in oblique direction forward and inward, being adapted to fit inside a peripheral annular groove formed on the outside of the needle head, from where they are extracted by bending when pushed by the appendages of the cited disk seal .

9. Single-use hydrodermic syringe according to claims 1, 7 and 8, characterized in that the said closure element of the plunger cavity is constituted by a discoidal button, snapped in by its edge in an annular groove formed in the mouth of the plunger cavity, said discoidal button being provided with a protruding anterior protuberance that constitutes the aforementioned first irreversible coupling means and which is provided with a peripheral step intended to be introduced under pressure into the countersunk hole of the needle head, from which it is impossible to exit by the opposing action of said second complementary coupling means, constituted by turn by an incoming step.

10. Single-use hypodermic syringe according to claim 1, characterized in that in the mouth of the tube cavity there are arranged means for retaining the plunger, which make it impossible to completely extract it from the inside of the tube.