Needle-casings for parenteral needles and method of manufacturing needle-casings.

0001The invention relates to a protective needle cover with an elongated, tubular housing with a central bore and a fastening element located at one end, by means of which the protective cover is removably attached to the base of a syringe arrangement.

0002Needle protection sleeves of this type are not new. For example, U.S. Patent No. 2,831,483 shows a plastic sheath with a mass of elastic material attached to the tip end of the hood. U.S. Patent No. 3,370,588 shows a needle guard that provides clearance between the needle tip and the hood tip. U.S. Patent No. 4,249,530 shows a similar arrangement. U.S. Patent No. 4,402,682 also shows a plastic / rubber needle guard. Other patents determining the state of the art are listed in the following table:<tables id="tabl0001" num="0001"><img file="EP0240787A2_D0001.tif" /></tables>

0003However, these known needle protection sleeves still have some disadvantages. It has proven to be particularly time-consuming and difficult for them to fit the elastic inserts described above into the needle guard housing. In addition, these known constructions are not readily suitable for high-speed automated assembly machines and techniques. In addition, the elastic insert in these needle covers is not secured against axial displacement. For this reason, there is a risk in the known needle protection sleeves that the needle tip does not penetrate the insert as intended and does not sit there properly.

0004Furthermore, the oblique grinding of the injection cannula (needle tip) causes a lateral evasion when penetrating into elastic materials, which can lead to slanted positioning of the protective needle cover or even to a side puncture.

0005Under these conditions, the elastic insert can no longer enclose the needle tip evenly and to the required extent, so that the aseptic termination of the needle can be endangered.

0006There is therefore in particular the task of creating a protective needle cover of the type mentioned at the outset which avoids the disadvantages mentioned, in particular increases the safety of a germ-free termination of the needle tip and enables easy and inexpensive production.

0007According to the invention this object is achieved in particular in that the bore narrows conically and in that at the end of the tubular housing facing away from the fastening a space in communication with the bore is formed for receiving an insert part made of elastic material which is held in the space in a narrow wall closure is.

0008As will be shown further below, this construction is suitable for simple and automation-capable, inexpensive production. The tight wall closure of the elastic insert prevents axial play and thus ensures a clean penetration and a clean fit of the needle.

0009The invention also relates to a method for producing a protective needle cover. This method is particularly characterized in that first an elongated, tubular housing is formed, which has a tapering central bore and an essentially cylindrical receiving space at one axial end of the housing, and that an essentially cylindrical insert part is then inserted into the receiving space of the housing is and then the wall end of the receiving space is deformed to encapsulate the insert.

0010The simplicity of the individual process steps allows a very fast automated production of the needle protection cover according to the invention with consistently safe and good processing. After the insert has been inserted into the substantially cylindrical space, the outer trailing edge of the receiving space can, for. B. be bent into the clear opening using heat and pressure. In particular, if the inner end of the receiving space is slightly tapered or narrowed conically, a tight seal can be achieved between the insert and the outer wall.

0011The invention is described in more detail below with the details that are essential to it using exemplary embodiments according to the invention and with the aid of the drawings.

0012Show it :<ul id="ul0001" list-style="none"><li>1 shows a schematically upright partial side view of a needle protection cover according to the invention, which is placed on the base of a typical syringe arrangement,</li><li>2 is an enlarged schematic sectional view taken along lines 2-2 of FIG. 1, showing the inner details of the needle cover,</li><li>3 is an enlarged sectional view in a schematic representation, showing the assembly of the individual parts of the needle cover,</li><li>4 shows a needle cover according to the invention, which is placed on another base type of an injection needle,</li><li>5 is an enlarged schematic sectional view taken along lines 5-5 of FIG. 4,</li><li>Fig. 6 is a plan view of a needle shield according to Fig. 4 and</li><li>7 is an enlarged schematic sectional view of the base-side end of the needle shield according to FIG. 4.</li></ul>

00131 to 3 show an inventive needle protection cover, generally designated 10. It is intended for attachment to the base 12 of a syringe assembly, which has a fairly smooth outer cylindrical surface 14.

0014The needle protective cover 10 is preferably made of rigid plastic material, e.g. B. made of polypropylene and has an elongated, tubular housing 20 with a receiving space 22 which is formed at a distal-axial end 23 of this housing 20 and contains a rubber insert 24. As shown, the wall of the housing is rounded at its outer, base-facing end 26 to form an enclosure for use, as explained in detail below. The receiving space 22 is connected to an elongated central bore 30 which, as shown, has a conically converging cross section, which in the present exemplary embodiment converges radially inwards in the direction of the receiving space 22 of the housing 20. The open syringe-side end 32 of the housing 20, which fits over the needle base 12, has a series of concentric, axially spaced ribs 34 and an outwardly diverging guide portion 36 which extends to the clear open end of the base side of the needle shield 10, around which Easy to put on the syringe assembly. The receiving space 22 for the rubber insert 24 has a substantially uniform diameter D 2 over its length. At its inner, syringe-facing axial end 39, however, it is slightly narrowed radially inward in order to achieve a firm and effective seal after the insert 24 has been installed.

0015The distal end 23 of the housing 20 is essentially cylindrical and delimits an initially open chamber into which the rubber insert 24 can be inserted without deformation. The slight slope 40 of the end edge of the housing wall simplifies the insertion of this rubber insert 24, which, as shown, has an essentially cylindrical shape and a constant diameter over its entire length. The diameter D 1 of the insert 24 is slightly smaller than the main diameter D 2 of the receiving space 22 and larger than the smallest diameter D 3 of the conically narrowed bottom area 38 of the receiving space 22, to which the central bore 30 of the housing 20 connects. After insert 24 is inserted, distal end 23 of housing 20 is brought into shape by the application of heat and pressure as shown in FIG. 2nd is shown in order to encapsulate and fix the insert 24 in this way by the radially inward deformation of the inner cylinder opening facing away from the syringe (cf. FIG. 3) and the final shape shown in FIG. 2. Before this deformation, the insert 24 is pre-compressed using a compression pin which acts along the central axis of the insert 24 through the opening 26a. During this compression phase, the outer final wall of the housing is deformed as described. The opening 26a is formed in the distal end 23 of the opening as soon as the compression pin is pulled out of the opening in the following step. This method has the advantage that it can be adapted to high-speed automatic machines for the production of protective needle covers with a constant hermetic seal.

00164 to 7 show a modified type of needle cover 10schutz according to the invention. The basic design of the housing 20ʹ and the insert 44 is generally similar to that which has already been described in connection with the basic design. Thus, the housing 20ʹ contains an elongated, tapered central bore 41 and so also the receiving space 42 for the insert 44 has a narrow, truncated cone-shaped base area 46 in order to ensure a firm and tight fit when the rubber insert 44 is used in essentially the same way as described above. In the present example, the protective needle cover 10ʹ is designed to be placed on a needle base 49 in an embodiment as shown in FIG. 5 is shown. Note that the needle base 49 has an enlarged head portion 50 which defines a circularly extending shoulder 52 with a neck portion 54 of the syringe body. In the example shown, the bottom end 56 of the housing of the needle shield 10ʹ has a radially inwardly directed rib 58, which adjoins its open, closing end, and has an inner diameter D 4 that is smaller than the maximum diameter D 5 of the base 49. The rib 58 has a slight bevel 62, which increases the diameter, towards the syringe in order to facilitate the pushing on of the edge bead over the needle base 49. The inner wall 64 of the attachment area 65 of the needle protection sleeve 10ʹ has in the present example a series of concentrically radially inwardly directed sealing bulges 66 with a diameter D 6 which is somewhat smaller in comparison to the diameter D 5 of the base 49, in order to tightly encompass the base 49 and a sealing one To ensure seat in the manner shown in Fig. 5.

0017The inner walls of the attachment area 65 end in a slightly curved connecting wall 68, which merges into the tapering central bore 41 through which the needle is guided when the needle protective cover 10ʹ is attached (FIG. 7).

00185 to 7, the mounting area 51 of the housing 20ʹ has a series of axially extending, circumferentially evenly spaced grooves 72 which give the mounting area 51 a certain degree of flexibility. This design feature ensures a firm placement on the placement area 51 even during the autoclave process. These recesses or keyways also virtually compensate for any manufacturing tolerances between the needle base 49 and the sealing ribs 66.

0019To form the distal end 23 of the housing 20, a unitary molding tool can be used which has a dome-shaped recess which fits the final rounded shape of the distal end 23 of the housing 20 and a pin projecting axially centrally from the dome. The subsequent assembly on a syringe arrangement after completion of the needle protective cover is facilitated by the conical narrowing of the central bore 30, which causes the needle to be guided. In the mounting area 51 of the housing 20ʹ (Fig. 5 to 7), a number of preferably axial grooves 72 or the like. Recesses are provided. These serve to increase the flexibility of this mounting area 51. These grooves 72 are dimensioned such that the mounting is ensured even during the expansion phase in the autoclave process.

0020All features mentioned in the claims and in the description can be essential to the invention individually or in connection.