Sanitary sheath for a syringe for insemination by straw and its method of manufacture

Abstract

The sheath (30) comprises a tube (31) and an end piece (32) that comprises a foot (33) introduced into an end portion of the tube (31), and a head (34) arranged in the extension of the tube (31). The foot (33) comprises, on the outer surface (40) thereof, a plurality of annular ribs (41-44) facing the inner surface (45) of the tube (31). The head (34) comprises a shoulder (38) facing the section (39) of the tube (31), projecting over the root of the foot (33). The end piece (32) and the tube (31) are attached to the periphery of at least one of said annular ribs exclusively by intrinsic welding. The method comprises the step of carrying out a peripheral tightening of the outer surface (37) of the tube on a level with the ribs (41-44), and the step of applying a sonotrode to the outer surface (35-36) of the head (34).

Claims

1. A sanitary sheath for a syringe for insemination by straw (10), comprising a tube (31) and a tip (32) attached to the tube (31), which tip comprises a tail (33) inserted into an end portion of the tube (31) and a head (34) disposed in line with the tube (31), said tip (32) comprising a duct opening into the tube (31) at a proximal end of the tail (33) and out from the sheath at an outside surface (35, 36) of the head (34), the duct comprising an axially oriented portion (53) narrowing from the proximal end of the tail (33), said tail (33) comprising on its outside surface (40) a plurality of annular ribs (41-44) facing the inside surface (45) of the tube (31), said head (34) comprising a shoulder (38) facing a rim (39) of the tube (31) and jutting relative to a base of the tail (33); wherein the tip (32) and the tube (31) are exclusively fastened by intrinsic welding exclusively at the periphery of one or more said annular ribs (41-44).

2. A sanitary sheath according to claim 1, wherein the tip (32) and the tube (31) are welded at a location of several of said annular ribs (41-44), with a different depth of weld for at least two said annular ribs (41-44).

3. A sanitary sheath according to claim 2, wherein the depth of weld is greater the further the annular rib (41-44) is from the proximal end of the tail (33) of the tip (32).

4. A sanitary sheath according to claim 1, wherein each said annular rib (41-44) comprises, on a side turned towards a distal end, a straight surface (60) which projects from a trough surface (61); and from a side turned towards the proximal end, a surface (62) inclined inwardly and towards the proximal end.

5. A method for manufacturing a sanitary sheath according to claim 1, further comprising: providing a tube (31) and a tip (32) comprising a tail (33) and a head (34), said tip comprising a duct opening at the proximal end of the tail (33) and at the outside surface (35, 36) of the head (34), which duct comprises an axially oriented portion narrowing from the proximal end of the tail (33), said tail (33) comprising on its outside surface (40) a plurality of annular ribs (41-44), said head comprising a shoulder (38) jutting relative to the base of the tail (33); inserting the tail (33) into an end portion of the tube (31) until the head (34) is disposed in line with the tube (31), the annular ribs (41-44) then facing the inside surface (45) of the tube (31), the rim (39) of the tube (31) facing said shoulder (38); performing peripheral clamping on the outside surface (37) of the tube (31) opposite said ribs (41-44); and applying a sonotrode for ultrasonic welding to the outside surface (35-36) of the head (34).

6. A method according to claim 5, wherein an outside diameter of said annular ribs (41-44) varies from one rib to another rib, increasing from the proximal end of the tail (33).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure of the invention will now be continued by the description of an embodiment, given below by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a diagrammatic view in longitudinal cross-section of a straw according to the prior art;

(3) FIG. 2 is a cross-section view of the distal end of a sheath according to the invention; and

(4) FIGS. 3 and 4 are side views of the head of that sheath, taken respectively from the top and from the front of FIG. 2.

DETAILED DESCRIPTION

(5) The sanitary sheath 30 illustrated in FIG. 2 is provided to cooperate as explained above with an artificial insemination syringe in which is disposed a straw such as the straw 10 illustrated in FIG. 1.

(6) The sanitary sheath 30 comprises a tube 31 and a tip 32.

(7) The tip 32 comprises a tail 33 inserted into an end portion of the tube 31 and a head 34 disposed in line with the tube 31.

(8) Remote from the tail 33, the head 34 has a rounded convex end surface 35 forming the distal end surface of the sanitary sheath 30.

(9) The part 36 of the outside surface of the head 34 situated between the surface 35 and the tube 31 is here of circular section, of the same diameter as the outside surface 37 of the tube 31. Thus, the surfaces 36 and 37 are flush with each other.

(10) The head 34 has a shoulder 38 facing the rim 39 of the tube 31 and jutting relative to the base of the tail 33.

(11) The tail 33 comprises on its outside surface 40 annular ribs of which there are four here, referenced 41 to 44 in the order of proximity to the head 34, with the rib 41 the closest to the head 34 and the rib 44 the furthest away.

(12) The attachment between the tube 31 and the tip 32 is achieved exclusively by intrinsic welding between the periphery of each of the ribs 41 to 44 and the inside surface 45 of the tube 31.

(13) As explained below, these welds are made by ultrasound.

(14) In the tip 32 there is formed a duct opening into the tube 31 at the proximal end of the tail 33 (the far end from the head 34) and outside the sheath at the outside surface of the head 34, here by two apertures 51 (FIGS. 3 and 4) situated at the junction between the portions 35 and 36 of the outside surface of the head 34.

(15) The duct comprises a transversely oriented portion 52 going from one to the other of the apertures 51 and an axially oriented portion 53, disposed between the proximal end of the tail 33 and the portion 52.

(16) The portion 53 of the duct narrows from the proximal end of the tail 33.

(17) The portion 53 is configured such that the portion of the tube 11 of the straw 10 situated in the neighborhood of the end 17 (furthest end from the stopper 12) can be inserted into the portion 53 and advance to a stop position in which the portion of the tube 11 situated in the neighborhood of the end 17 is clamped around by the wall which delimits the portion 53.

(18) This clamping round provides at the same time the stop for the pushing-in of the straw into the sheath and the liquid-tightness between the straw and the sheath.

(19) The outside surface 40 of the tail 33 will now be described in more detail with the aid of FIGS. 3 and 4.

(20) Each of the ribs 41 to 44 comprises: on the side turned towards the distal end (which side can be seen to the right in FIGS. 2 to 4) a straight surface 60, that is to say a surface oriented according a transverse plane, which projects from a trough surface 61; and on the side turned towards the proximal end (which side can be seen to the left in FIGS. 2 to 4), a surface 62 inclined inwardly and towards the proximal end.

(21) Here, the trough surfaces 61 have the same diameter and the inclined surfaces 62 have the same inclination.

(22) The inclined surface 62 of the ribs 41, 42 and 43 is joined to its base (the part of smallest diameter situated on the opposite side to the straight surface 60) at the trough surface 61 from which projects the straight surface 60 of the next rib.

(23) The inclined surface 62 of the rib 44 joins to its base at a guide surface 63 of which the diameter is slightly greater than the diameter of the trough surfaces 61.

(24) The base surface of the shoulder 38 of the head 34 joins to a wedging surface 64 of which the diameter is slightly greater than the diameter of the guide surface 63.

(25) Between the wedging surface 64 and the nearest trough surface 61, is located a transition surface 65 which is inclined inwardly and towards the distal end.

(26) The outside diameter of the ribs 41 to 44, which here corresponds to the greatest diameter of the straight surfaces 60 and of the inclined surfaces 62, varies from one rib to the other, increasing from the proximal end of the tail 33.

(27) Thus, the outside diameter of the annular rib 44, which is the closest to the proximal end, is smaller than the outside diameter of the rib 43, which is itself smaller than the outside diameter of the rib 42, which is itself smaller than the outside diameter of the rib 41.

(28) The straight surface 60 and the inclined surface 62 of the rib 41 meet.

(29) For each of the ribs 42, 43 and 44, there is, between the straight surface 60 and the inclined surface 62, a cylindrical surface 66 having the outside diameter of the corresponding rib.

(30) A description will now be given of how the tube 31 and the tip 32 are attached to each other.

(31) First the tail 33 of the tip 32 is fitted by insertion in an end portion of the tube 31 until the rim 39 comes opposite the shoulder 38.

(32) The diameter of the inside surface 45 of the tube 31 is capable of varying to a relatively great extent, for example by 0.1 mm, due to its manufacture by extrusion.

(33) The ribs 41 and 44 have been configured accordingly: when the diameter of the inside surface 45 is at the maximum of the range of variation, the inside surface 45 comes at least into contact with the rib 41; and

(34) when the diameter of the inside surface 45 is at the minimum of the range of variation, the inside surface 45 comes into contact with each of the ribs 41 to 44.

(35) The fact that the outside diameter of the ribs 41 to 44 increases from the proximal end facilitates the insertion of the tail 33 into the tube 31.

(36) The surface 63 gives first guidance along the inside surface 45 before the latter encounters the rib 44.

(37) When the tip 32 is inserted into the terminal portion of the tube 31, the surface 64 stabilizes the inside surface 45 in the neighborhood of the shoulder 38.

(38) Once the tail 33 of the tip 32 has been inserted into the terminal portion of the tube 31, peripheral clamping on the outside surface 37 of the tube 31 is carried out opposite the ribs 41 to 44 and a sonotrode for ultrasonic welding is applied to the outside surface of the head 34.

(39) Because the only location at which there is clamping between the surface of the tip 32 and the surface of the tube 31 is opposite the ribs 41 to 44, and because of the fact that those ribs form an edge, it is at the zone of contact between the ribs 41 to 44 (periphery of those ribs) and the tube 31 that their materials will heat up, soften and mix, which, after cooling, will form an intrinsic weld, that is to say involving only the material of the tube 31 and the material of the tip 32.

(40) Of course, the material of the tube 31 and the material of the tip 32 are selected so they can be welded ultrasonically and more generally intrinsically, that is to say that those materials are mixable when they are have been softened.

(41) Here, the material of the tube 31 and the material of the tip are transparent. They are respectively PVC (poly vinyl chloride) and PMMA (poly methyl methacrylate).

(42) In principle, the ribs 41 to 44 are configured such that each of them is welded to the tube 31.

(43) Given the difference in diameters of the ribs 41 to 44, the depth of weld increases from the proximal end, that is to say that the depth of weld between the rib 44 and the tube 31 is smaller than the depth of weld between the rib 43 and the tube 31 which is itself smaller than the depth of weld between the rib 42 and the tube 31 which is itself smaller than the depth of weld between the rib 41 and the tube 31, as can be seen in FIG. 2.

(44) When the diameter of the inside surface 45 is very great, the weld will be made at least with the rib of greatest diameter, that is to say the rib 41.

(45) It should be noted that the welds between the tip 32 and the tube 31 are made exclusively at the location of the ribs 41 to 44.

(46) In particular, there is no weld between the shoulder 38 of the tip 32 and the rim 39 of the tube 31.

(47) This makes it possible to avoid weld flash projecting from the outside surface of the tube 31 or from the head 34; and the risks of injuries to the animal, which could be caused by such a weld flash, are thus avoided.

(48) On the contrary, in a general manner, as the welds are exclusively internal to the sheath 30 those risks are eliminated.

(49) In a variant not illustrated, the number of annular ribs of the outside surface of the tail and the tip is different from four, for example two or five.

(50) In another variant not illustrated, the duct internal to the tip such as 32 is differently conformed, for example being oriented uniquely in the axial direction, while opening by the center of the surface such as 35.

(51) Numerous other variants are possible according to circumstances, and in this connection it is to be noted that the invention is not limited to the examples described and shown.