IMPLANT SYRINGE

Abstract

An implant syringe with a syringe needle holder, having an axially adjoining preparation receptacle; an outer sleeve with a radially projecting front gripping section, connected together for common axial movement; an inner sleeve, on which the outer sleeve is slidably located and in which the syringe needle is movable with the preparation receptacle. The inner sleeve has axial slots, through which webs engage, which connect the outer sleeve to the syringe needle holder, further including a rod-shaped piston, fastened to a rear gripping section partially surrounded by a rear sleeve, movably engaged in the inner sleeve. The rod-shaped piston is advanceable through the preparation receptacle in the syringe needle so that a distance remains between the tip of the syringe needle and the head end of the piston approximately equal to the length of the preparation to be delivered.

Claims

1. An implant syringe comprises a syringe needle holder, which holds an injection needle, an axially adjoining preparation receptacle and an outer sleeve with a radially projecting front gripping section on its rear end section, wherein the injection needle holder and the outer sleeve are connected together for common axial movement, including an inner sleeve, on which the outer sleeve is slidably located and in which the syringe needle is movable with the preparation receptacle, wherein the inner sleeve has axial slots, through which webs extend, which connect the outer sleeve to the syringe needle holder, further including a rod-shaped piston, which is fastened to a rear gripping section and is partially surrounded by a rear sleeve, which movably engages in the inner sleeve, wherein the rod-shaped piston is advanceable through the preparation receptacle into the syringe needle so far that a spacing remains between the tip of the syringe needle and the head end of the piston, which is approximately equal to the length of the preparation to be delivered, and the advance of the piston is limited by the rear gripping section reaching the rear edge of the inner sleeve, wherein the outer sleeve is releasably locked in the advanced starting position with the syringe needle exposed by a blocking device, which is arranged on the inner sleeve and projects radially outwards, and wherein the blocking device is moved radially inwards on advance of the rear sleeve into its end position, whereby the outer sleeve is released and is retractable by means of the front gripping section on the inner sleeve.

2. An implant syringe as claimed in claim 1, wherein the blocking device is a spring arm cut free from the inner sleeve, the head end of which, which is preferably shaped in the form of a locking hook, projects radially beyond the inner sleeve in the unloaded state and blocks the retraction of the outer sleeve.

3. An implant syringe as claimed in claim 1, wherein the rear sleeve has an axial slot, which slides over the spring arm, which is thus drawn radially inwardly by at least one oblique surface.

4. An implant syringe as claimed in claim 1, wherein the front end position of the rear sleeve is reached when the rear gripping section abuts the rear edge of the inner sleeve.

5. An implant syringe as claimed in claim 1, wherein the retraction of the outer sleeve is limited by the two gripping sections engaging one another.

6. An implant syringe as claimed in claim 1, wherein when the outer sleeve is completely retracted, the piston projects beyond the tip of the syringe needle.

7. An implant syringe as claimed in claim 1, wherein projecting into the passage of the preparation receptacle there is a spring arm which, in the unloaded state, blocks the movement of the preparation.

8. An implant syringe as claimed in claim 7, wherein the spring arm projects in a flatly convex curved manner into the passage.

9. An implant syringe as claimed in claim 1, wherein the inner sleeve includes a head section, which adjoins the slotted region and is closed over the periphery and which covers the tip of the syringe needle in its retracted end position.

10. An implant syringe as claimed in claim 9, wherein the head section has a forwardly tapering frustoconical shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGS. 1a to 1c are different views of an embodiment of the implant syringe;

[0018] FIGS. 2a to 2d are different views of the rear sleeve with the rod-shaped piston;

[0019] FIGS. 3a to 3d show further details of the rear sleeve;

[0020] FIG. 4 is a view of the inner sleeve composed of two parts;

[0021] FIGS. 5a to 5d are different views of the front portion of the inner sleeve;

[0022] FIGS. 6a to 6d are different views of the rear portion of the inner sleeve;

[0023] FIG. 7 is a longitudinal sectional view of the outer sleeve;

[0024] FIGS. 8a to 8d are different views of the preparation receptacle;

[0025] FIG. 9 shows the blocking device of the outer sleeve.

DETAILED DESCRIPTION

[0026] FIGS. 1a to 1c show an initial state of the implant syringe, in which the syringe needle 1 is covered by a removable protective cap 2. The removable protective cap 2 is readily removably snap connected to an outer sleeve 3. The outer sleeve 3 has an elongate cylindrical shape, wherein a radially projecting front gripping section 4 is integrally formed at its end section on the right in the figures. The outer sleeve 3 is firmly connected by means of a plurality of radially inwardly extending webs 5 to a needle holder 6, in which the syringe needle 1 is fastened. A preparation receptacle 7 is so arranged axially behind the needle holder 6 that its passage 8 is in alignment with the passage of the syringe needle 1. Situated in this preparation receptacle 8 there is a preparation, which is not shown, which, when the implant syringe is used, is delivered e.g. into the abdominal wall of a patient.

[0027] The outer sleeve 3 sits (when it is not blocked) movably on an inner sleeve 9, which is composed of a front portion 10 and a rear portion 11. The front portion 10 includes a front section 12, which narrows frustoconically and which is closed in the peripheral direction and covers the tip of the completely retracted syringe needle. The axially adjoining region includes webs 13, which are spaced in the peripheral direction and are provided with slits 14, whereby formed on the end sections of two webs there are hooks 15, which latch into openings 16 in the rear portion 11 of the inner sleeve 9 in order to connect the two portions.

[0028] The rear portion 11 of the inner sleeve 9 includes a spring arm 17, which is cut free from the wall of the inner sleeve portion 11 and projects radially outwardly with a locking hook 25. This spring arm 17 with the locking hook 25 serves as a blocking device for the outer sleeve 3 so long as a rear sleeve 18 is not slid into its end position in the rear portion 11 of the inner sleeve 9.

[0029] Integrally formed at the rear end of the rear sleeve 18 there is a flat gripping member 19, secured centrally to which in the sleeve 18 there is a rod-shaped piston 20. The rear sleeve 18 includes a slot 21 extending in the axial direction, which, when the rear sleeve 18 is slid into the rear portion 11 of the inner sleeve 9, so cooperates with the spring arm 17 by means of an oblique surface 26 that its locking hook 25 is drawn radially inwards. This is the case when the inner surface of the rear gripping member 19 abuts the rear edge 22 of the inner sleeve 9, whereby this position is readily releasably locked.

[0030] The outer sleeve 3 can now be retracted together with the injection needle 1 in its end position, in which the two gripping members 4 and 19 engage one another. The tip of the injection needle 1 is now situated within the frustoconical section 12 of the inner sleeve 9.

[0031] FIG. 1a shows a safety sleeve 22, which, in the initial state of the implant syringe, blocks the advance of the rear sleeve 18 and thus of the piston 12 with webs. The safety sleeve 22 is removed before use of the implant syringe.

[0032] FIGS. 8a to 8d show the preparation receptacle 7, which is arranged behind the syringe needle holder. Projecting into the through passage 23 of the preparation receptacle 7 there is a spring arm 24, which is cut free from the peripheral wall of the preparation receptacle 7 and which, in the unloaded state, so constricts the through passage 23 that a preparation received therein cannot pass the spring arm 24. The spring arm has a gently convex shape projecting into the passage 23 and is constructed integrally with the remainder of the preparation receptacle 7. When the piston 20 is advanced, it presses the preparation smoothly through the constriction, whereby the spring arm is pressed somewhat upwardly. The preparation can thus not be damaged.

[0033] FIG. 9 is an enlarged schematic view of the blocking device for the outer sleeve 3. The inner sleeve 9 engages a rear annular shoulder 27 of the outer sleeve in this view with a radially outwardly projecting locking hook 25. When the rear sleeve 18 is advanced in the direction of the arrow 28, an oblique surface 26 on the rear sleeve 18 slides along a release ramp 29 on the inner sleeve 9, whereby the locking hook 25 is pulled radially inwardly and permits the outer sleeve 3 to be pulled back.