DISPOSABLE SYRINGE FOR AUTOMATIC MIXING OF A FIRST AND A SECOND COMPONENT.

Description

B098AOOQ633 DISPOSABLE SYRINGE FOR THE AUTOMATIC MIXING OF A FIRST AND A SECOND COMPONENT. On behalf: B.F. ELETTROMECCANICA S.r.l. Based in: CHIESANUOVA (R.S.M.) - Strada C. Simoncini, 7. DESCRIPTION OF THE INVENTION The present invention relates to the technical sector concerning sanitary instruments, in particular it refers to a disposable syringe for the automatic mixing of a first component and a second component, for example of an active principle with a diluent, the mixture of which must be injected. Syringes of the known type, and in particular those used in the medical sector, essentially consist of a cylinder in which a piston slides and a metal needle can be associated with one end. The use of known syringes provides that the user, once the sterilized needle has been inserted into the appropriate seat located at the end of the cylinder of the syringe, uses a hacksaw to cut the neck of a vial containing a liquid diluent in order to be able to insert the needle to aspirate said liquid inside the cylinder, then introduce it into a bottle containing the active principle in powder form, after having pierced the rubber stopper of the bottle by the needle. Then, once the two components have been mixed, the mixture is drawn into the syringe in order to complete the preparation of the syringe for injection. This procedure is extremely disadvantageous as the needle must pierce the relatively hard rubber stopper of the bottle before being actually used for the injection: in this step it often happens that the tip of the needle is damaged and therefore that the needle loses its its particular characteristic of being as "painless" as possible in correspondence with the injection on the patient. Furthermore, the use of at least four disposable elements for each injection (la syringe, the vial containing the diluent liquid, the hacksaw, and the bottle containing the active ingredient) as the use of "disposable" materials is relatively high, the risk of contaminating the needle and the mixture to be injected before performing the injection and the operating methods for preparing a simple injection become very complicated and must always be performed by specialized personnel. The main object of the invention therefore consists in proposing a disposable syringe which allows the user to automatically mix the active principle with the diluting liquid and which therefore greatly reduces the risk of contamination of the needle before injection. A further object is to propose a syringe which is easy and safe to use, as well as being simple to make and of low cost. The objects indicated above are obtained in accordance with the contents of the claims. The characteristics of the invention are highlighted below with particular reference to the attached drawings, in which: figure 1 illustrates a longitudinal sectional view of a syringe object of the invention in correspondence with a charged condition; Figure 2 illustrates the syringe of Figure 1 at a mixing condition; Figure 3 illustrates the syringe of Figure 1 in an empty condition. With reference to figures 1 to 3, 1 indicates a disposable syringe for the automatic mixing of a first component 2, for example an active principle in powder form, and a second component 3, for example a liquid diluent, mainly comprising a cylinder 4, a plunger 5 and a needle 14. The cylinder 4 consists of a tubular element, circular in shape in the preferred embodiment, having an open end and the remaining closed end flowing into an external dispenser 13, intended to support the needle 14 and whose mouth is sealed by means of one tab 12, for example of laminar plastic material or aluminum or polycoated paper. The piston 5 is inserted from the open end of the cylinder 4 so that its head, on which a membrane 11 is hermetically welded, defines a first chamber 6, together with the closed end of the cylinder 4, the dispenser 13, the tongue 12 and to the side walls of the cylinder itself. At the free end of the cylinder 4, a pair of wings 4a facing towards the outside of the syringe 1 are fixed, while inside the cylinder there is a series of internal perimeter protrusions 16, constituting teeth facing towards the inside of the cylinder 4 and towards the dispenser 13. The piston 5 consists of an external hollow piston 8, inside which an internal piston 9 is inserted in a sliding and coaxial manner. The head 8a of the external piston 8 is provided on the perimeter with a ring gasket 17 capable of ensuring the hydraulic seal between the external piston 8 and the cylinder 4. The external piston 8 is provided, in correspondence with its free end 8b, with a pair of protrusions 19 directed towards the outside of the piston, and in the vicinity of its free end 8b, with a series of external perimeter protrusions 15 which constitute teeth facing towards the outside of the piston 8 and towards the dispenser 13. Furthermore, the free end 8b of the external piston 8 is provided with a seat 18 of such dimensions as to be able to house a shim 9b fixed to the free end of the internal piston 9. When the inner piston 9 is partially inserted into the outer piston 8, a second chamber 10 is defined between the side walls of the latter, the head 9a of the inner piston 9, and the diaphragm 11. It is advantageous to point out, for example, that the membrane 11 and the tongue 12 are made of a laminar plastic material or aluminum or poly-coated paper. Ing. GIAMPAOLO AGAZZANI National Order of Industrial Property Consultants The operating procedures for using the syringe 1 are very simple, since the operator starts from a loading condition C of the syringe itself, illustrated in figure 1, in which the first chamber 6 contains, for example, the diluent liquid 3 and the second chamber 10 contains the active principle 2, mainly in powder form. Then the operator, gripping the syringe 1 by the external piston 8, leveraging on the protrusions 19, exerts pressure on the swelling 9b of the internal piston 9 until the latter is inserted complementary into the seat 18. In this phase, the head 9a of the internal piston 9 exerts a pressure on the active ingredient 2 so that the latter forces the membrane 11 and comes out completely from the second chamber 10, pouring into the first chamber 6 in which the diluent liquid 3 is present and implementing a mixing condition M for syringe 1, shown in figure 2. The operator can therefore shake the syringe 1, thus facilitating the mixing of the active ingredient 2 with the diluting liquid 3 inside the first chamber 6. At this point, the operator couples the support 14a of the needle 14 with the dispenser 13 , allowing the tongue 12 to be pierced by the end of the needle inside the support 14a. The operator holds the syringe 1 for the cylinder 4 and, by leveraging the fins 16, exerts a pressure on the heads 8b and 9b, coplanar, respectively of the external 8 and internal 9 pistons, so that the mixture 7 of diluent 3 and active ingredient 2 is forcibly ejected from the chamber 6 through the dispenser 13 and the needle 14, allowing the injection and the achievement of a discharge condition S of the syringe 1, illustrated in figure 3. The main advantage of the invention is that of providing a disposable syringe capable of allowing the user to automatically mix the active principle with the diluent liquid as well as drastically reducing the danger of contamination of the needle before injection. A further advantage consists in providing a syringe that is easy and safe to use, as well as Ing. GIAMPAOLO AGAZZAN1 National Order of Conadsiti in Industrial Property simple to make and low cost.

Claims

CLAIMS 1) Disposable syringe for the automatic mixing of a first component 2 and a second component 3 comprising a cylinder 4, provided with a dispenser 13 and inside which a plunger 5 is intended to slide between a mixing condition M of said syringe 1, in which the mixture 7 to be injected, consisting of the first and second component, is inside a first chamber 6, comprising said dispenser 13 and defined by said cylinder 4 and the head of said plunger 5, and a discharge condition S of said syringe 1, wherein said mixture 7 is expelled from said chamber 6, said syringe 1 being characterized in that said piston 5 is constituted by an external piston 8 inside which an internal piston 9 slides coaxially which, in correspondence with a loading condition C, defines a second chamber 10 between the head 9a of said internal piston 9, the side walls of said external piston 8 and a membrane 11 sealing the head 8a of the latter, with said internal piston 9 intended to translate longitudinally in the direction of said head 8a, in the passage from said loading condition C to said mixing condition M, thus causing the fracture of said membrane 11 and the complete pouring of said first component 2 into said second component 3,said first chamber 6 further having said dispenser 13 sealed by means of a tab 12 pierceable by a hollow needle 14 through which said mixture 7 is expelled from said first chamber 6 in the passage from said mixing condition M to said discharge condition S by virtue of the simultaneous longitudinal movement of said pistons, external 8 and internal 9, towards said dispenser 13., 2) Syringe according to claim 1 characterised in that said external piston 8 is provided, in proximity to its free end 8b, with a series of external perimeter protrusions 15 capable of engaging complementarily by interlocking with a series of internal perimeter protrusions 16 of said cylinder 4 in correspondence with the aforementioned IX "S o S*(S discharge condition S so as not to allow the reuse of said syringe 1. 3) Syringe according to claim 1 characterised in that said head 8a of said external piston 8 is provided around the perimeter with at least one gasket 17 capable of ensuring hydraulic sealing between said external piston 8 and said cylinder 4. 4) Syringe according to claim 1 characterised in that the free end 8b of said external piston 8 is provided with a seat 18 capable of housing a nozzle 9b fixed to the free end of said internal piston 9 in correspondence with said mixing conditions M and discharge S. 5) Syringe according to claim 1 characterised in that said membrane 11 and said tab 12 are made of a plastic or aluminium laminar material or of polythene paper. 6) Syringe according to claim 1 characterised in that said membrane 11 is pre-fractured in such a way as not to detach from the head 8a of said external piston 8 in correspondence with said mixing conditions M and discharge S. 7) Syringe according to claim 1 characterised in that a pair of fins 4a facing outwards from said syringe 1 are fixed at the free end of said cylinder 4. 8) Syringe according to claim 1 characterised in that at least one projection 19 facing outwards of the latter is fixed at the free end 8b of said external piston 8. 9) Syringe according to claim 1 characterised in that said first component 2 consists of an active ingredient of the powder type and said second component 3 consists of a liquid diluent. 10) Syringe according to claim 1 characterised in that said first component 2 is constituted by a liquid diluent and said second component 3 is constituted by a Ino- GIAMPAOLO AGAZZANI active ingredient in powder form. Bologna, November 13, 1998 The Mandatory Engineer Giampaolo Agazzani OtìNA -ETTI NARIO FROVIKCIFlu OFFICE COMMERCE 0 t Z.hF.GlANATE OF Q OFFICES THE I. GIAMPAOLO AGAZZANI National Line of Industrial Property Consultants