BG87Y1 - Injector-ampule adaptor for autoinjector (11) 88 - Google Patents

Abstract

Spray-plug attachment for an auto-injector consisting of a hollow cylindrical body with a thread at the rear open end for connection to the housing of a trigger mechanism and a closed front end with a weakened central portion at the forehead or a central opening closed by a membrane along the axis of which are provided in series with an injection needle and an ampoule with an injection fluid characterized by characterized in that the injection fluid ampoule (5) is a resiliently cylindrical, a niche body whose front face has a centrally located recess (8) a truncated cone, and the rear end of the needle (4) being fixed in a disc whose forehead on the side of the ampoule has a frustoconical protrusion (7) of dimensions the same as the dimensions of the recess- (8) and the height of the truncated cone is equal to the sum of the thicknesses of the folds (9) of the surrounding ampoule wall (5).

Description

TECHNICAL FIELD

The utility model refers to a syringe attachment that will find application in the medical field, especially for devices for intramuscular injection of drug liquids, and used as a disposable device to an automatic injector.

BACKGROUND OF THE INVENTION

An attachment to an auto-injector is known, which is a hollow conical body with an axial opening in the front face and a threaded rear end. It houses a cylindrical cartridge, at the front end of which has a hub flange around an axial opening, which is sealed with a punch cap. Along the axis of the cartridge there is a sequential injection needle and a harmoniously elastic ampoule with injection fluid. The front end of the needle lies freely in the hub and its back end is fixed to the stop, fixed fixedly with the possibility of disassembly on the axis of the piston, resting tightly with its rear end in the front face of the ampoule, so that the back end of the needle extends beyond the abutment and in the initial position rests on the front face of the piston. In the center of the front face of this piston there is a shaped socket, surrounded by a ring which is concentric to its axis, with a drawn out and bent towards the center edge, which the ring engages the stop on a groove carved into its surrounding surface. The front surface of this abutment has a shape corresponding to the shape of the inner surface of the socket. The rear end of the cartridge is closed by a lid that is a membrane or hard disk covered by a sealing ring.

This design of the attachment and its components aims at sealing it in the course of the injection fluid and ensuring sterility in the space around the needle. The goal is achieved with a multi-element construction, which is complex, expensive, difficult both to make the individual elements and to mount.

There is a well-known injection molding attachment for an auto-injector, representing a hollow cylindrical body with an internal thread on the extended rear open end, and a closed front end with a flat face, in which there is a thin central portion. A needle and an ampoule of constant cylindrical shape containing the injection fluid are arranged alternately along the axis of this body. The anterior end of the needle is free and the posterior is gripped in a region of distance from the tip, fixed on the axis of the piston, in the back of which an annular groove is formed, and in the front of the ampoule, the radial size of the annular groove is convex. surrounding a thin section from the front face of the ampoule. The length of the injection needle section from the back of the piston to its tip is greater than the height of the rings. The rear end of the ampoule is closed tightly by a cylindrical stopper in which it rests the piston of the actuator and pushes it forward when injected.

This design does not provide sufficient sealing in the course of the liquid, as well as complete ejection of the liquid from the ampoule. Closing the ampoule with a cylindrical stopper does not prevent the injection fluid from flowing in the opposite direction.

TECHNICAL NATURE OF THE USEFUL MODEL

The automatic injector syringe assembly consists of a hollow cylindrical body with a thread in the rear open end for connection to the actuator housing and a closed front end with a tapered central portion in the forehead or a central opening closed by a membrane. An injection needle and an injection liquid ampoule are placed alternately along the axis of the cylindrical body. According to a useful model, the injection fluid ampoule is an elastically harmonic body, the needle being fixedly fixed to a disk whose face on the ampoule side has a cone-shaped projection, and the ampoule-supporting head therein is of the same shape and dimensions. The height of the truncated cone is equal to the sum of the thicknesses of the folds of the surrounding wall of the ampoule. The thickness of the central portion of the front face of the cylindrical body is less than the thickness of the bottom of the indentation of the front face of the ampoule. In one embodiment, the rear face of the ampoule in contact with the piston of the actuator is thickened relative to the surrounding wall, and in another embodiment, reinforced with a layer of solid material. The back end of the attachment body is closed.

The proposed construction of the syringe attachment, and in particular the conical contact surfaces between the ampoule and the piston needle around the puncture site, provide complete sealing that does not allow injection fluid to escape from the needle. An optimal sequence of processes in the auto-injector is ensured. The construction is easily feasible, technologically, the desired dimensions and qualities of the individual elements can be controlled during manufacture.

DESCRIPTION OF THE FIGURES Attached

Figure 1 is a longitudinal section view of the syringe attachment at the starting position;

Figure 2 is a longitudinal section view of the syringe attachment in the end position of the piston of the actuator;

Figure 3 is an enlarged section view of the contact area between the elastic ampoule and the needle disc and the front face of the attachment body.

EXAMPLES FOR IMPLEMENTATION

The syringe attachment consists of a hollow cylindrical body 1 with a closed front end and an open rear end. The front face has a central tapered section 2. The rear open end has an extension 3, on the inside of which a thread is threaded to join the actuator housing. An injection needle 4 and an elastic harmonic ampoule 5 with the injection fluid are arranged alternately along the axis. The needle 4 is fixedly fixed to the axis of the disk 6, whose face on the side of the ampoule 5 has a projection 7 in the form of a truncated cone. The front face of the ampoule 5 is concave to the inside of the ampoule, the recess 8 being the same in shape and size of the conical projection 7.

The height of the truncated cone h is equal to the sum of the thicknesses of the folds 9 of the surrounding wall of the ampoule. The thickness b of the central portion in the front face of the cylindrical body is 2 times less than the thickness b1 of the front face of the ampoule, and the face 10 of the ampoule 5 in contact with the piston 11 of the actuator is reinforced by a second layer of the same material. The rear opening of the attachment body is closed by a membrane 11. In one embodiment not shown in the drawings, the rear opening of the attachment body is closed and sealed with a peripheral protrusion from the rear face of the ampoule.

USE OF USEFULLY

MODEL

The injector is prepared for operation by winding the attachment against the housing, the actuator locks in the rear position of the piston 11. To release the injection, the piston 11 pushes the ampoule 5 forward, which transmits pressure to the disk 6, whereby the front needle end 4 pierces the forehead of the cylindrical body, pierces the skin and enters the muscle. Stop the needle 4 from moving forward and continue pushing the piston 11 on the rear face of the ampoule 5 causing the front face of the ampoule to pierce, with fluid entering the needle 4. Further movement of the piston 11 shrinks the ampoule 5 axially to its full folding and ejecting the injection fluid completely.

Claims

Claims (2)

An auto-injector syringe attachment comprising a hollow cylindrical body with a thread in the rear open end for connection to the actuator housing and a closed front end with a tapered central portion in the forehead or a central opening closed by a membrane along which the axis are arranged alternately with the injection needle and the injection fluid ampoule, characterized in that the injection fluid ampoule (5) is an elastically cylindrical, harmonic body whose forehead has a centrally located recess athene (8) with a cone-shaped cone, and the posterior end of the needle (4) is fixedly fixed to a disc whose face on the ampoule side has a projection (7) with a cone-shaped cone with dimensions equal to the dimensions of the indentation (8) and the height of the truncated cone is equal to the sum of the thicknesses of the folds (9) on the surrounding wall of the ampoule (5). Automatic injector syringe attachment according to claim 1, characterized in that the bottom of the recess (8) of the harmonically elastic ampoule body (5) has a thickness greater than the thickness of the central portion (2) in the front face of the cylindrical body (1). Attachment: 3 figures