Hypodermic syringe with parts disposable after use
1 Apr. 22, 1975 1 1 HYPODERMIC SYRINGE WITH PARTS DISPOSABLE AFTER USE [75] Inventor: Henri Rimbaud, Paris, France [73] Assignee: Laboratoire SPAD,  
 Quetigny-les-Dijon, France [22] Filed: Nov. 22, 1972 [21] Appl. No.: 308,844  
 [30] Foreign Application Priority Data Dec. 13, 1971 France 71.44606 [52] [1.5. CI. 128/218 DA; 128/218 P [51] Int. Cl. A6lm 5/24; A6lm 5/22 [58] Field of Search.... 128/218 R, 215, 221, 281 P, 128/218 PA, 218 M, 218 D, 218 DA, 234,  
 261, 220, 218 F, DIG. 5  
 F r a 5 r 3,410,267 11/1968 Nojd 128/218 D 3,433,216 3/1969 Mattson 128/D1G. 5 3,494,201 2/1970 Roach 128/218 R 3,545,427 12/1970 Ryan 128/2 F 3,583,399 6/1971 Ritsky 128/218 D FOREIGN PATENTS OR APPLICATIONS 1,201,009 9/1965 Germany 128/218 R 876,742 4/1943 Germany 128/215 Primary Examiner-Richard A. Gaudet Assistant E.\&#39;aminer.l. C. McGowan [57] ABSTRACT A hypodermic syringe of the kind comprising an assemblable syringe head and syringe body; a protective case for the syringe body; a cartridge containing a dose of anaesthetic intended for support in the syringe body; and a sterilization and presentation support for the syringe body, cases and cartridges. The hypodermic syringe having a head with a tip adapted for connection to the body, a rod slidingly mounted in the axial direction in the tip, gripping elements fixed to the tip and to the exterior free end of the rod, the body being hollow, and adapted to receive a cartridge of anaesthetic, having at one end threads for being fixed to the tip and adapted at the other end to receive a double needle holder, the gripping element fixed to the tip being mounted on the latter adjustably in the longitudinal direction with respect to the gripping element fixed to the exterior end of the rod.  
 4 Claims, 8 Drawing Figures HYPODERMIC SYRINGE WITHPARTS DISPOSABLE AFTER USE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to hypodermic syringes and in particular to those in which the majority of the parts are supplied in a sterile condition and are disposable after use.  
 2. Description of the Prior Art Syringes. particularly those used by dentists, are known which comprise a syringe head for permanent use, a syringe body supplied in sterile condition and disposable after use, and a cartridge containing an anaesthetic devised to be placed in the body of the syringe for the purpose of an injection.  
  The bodies and the cartridges are supplied in packages which the user has to open, and from which he has to take the articles directly with his fingers. Furthermore, the cartridges are not perfectly sterile and the user frequently has to sterilize the crimped joint which blocks one end of the cartridge and through which the anaesthetic is removed.  
  These operations have to be performed by numerous time consuming hand movements and in such a way that asepsis is not absolutely guaranteed.  
  An object of the present invention is to provide a syringe comprising a head which is suitable for all users irrespective ofthe size of their hand, and a syringe body supplied in sterile condition which is fitted on to the head simply and rapidly without being touched by the fingers.  
  A further object of the invention is to provide a syringe comprising a body disposable after use with which the known conventional cartridges of anaes thetic can be used as well as novel cartridges specially appropriate to the syringe of the invention and providing absolute guarantee of asepsis without the necessity of an additional sterilization at the time of their use.  
  Yet a further object of the invention is to provide a syringe with a permanent head and with body supplied in a sterile condition which may be disposed of after use but with which a plurality of injections can nevertheless be made successively by replacing the empty anaesthetic cartridge by a full cartridge.  
  A still further object of the invention is to provide a syringe with body disposable after use using anaesthetic cartridges supplied in a sterile condition with which the suction after driving the needle into the flesh, in order to verify whether the point of said needle is located in a blood vessel can be performed automatically by means of a simple relaxation of the pressure exerted upon the liquid to be injected.  
  Another object of the invention is to provide a package and a support for the body and for the cartridges supplied sterile which will ensure that asepsis is maintained during the delivery and the storage of said articles and permitting them to be fitted on to the head of the syringe without being touched by fingers.  
 SUMMARY According to the invention there is provided a hypodermic syringe of the kind comprising an assemblable syringe head and syringe body, the head having a tip adapted for connection to the body. a rod slidingly mounted in the axial direction in the tip, gripping elements fixed to the tip, and to the exterior free end of the rod. the body being hollow, and adapted to receive a cartridge of anaesthetic, having at one end means for being fixed to the tip and adapted at the other end to receive a double needle holder. the gripping element fixed to the tip being mounted. on the latter adjustably in the longitudinal direction with respect to the grip ping element fixed to the exterior end of the rod.  
 Suitably the tip comprises a sleeve in which the rod slides, rings being stacked on the said sleeve, locking means for the rings in the axial direction being fitted at one end of the sleeve. the gripping element being constituted by a disc interposed between two rings ofthe set of rings, the locking means being demountable to enable the disc to beinterposed between any two other rings.  
  In one embodiment a second disc is interposed between the rings at a point remote from the first disc. The two discs may have a frustoconical profile, one being flared towards the gripping element fixed to the rod and the other being flared in the opposite direction.  
  Alternatively, the gripping element may comprise two spaced double lugs interposed between the stacked rings and clamped along a sleeve in which the rod slides. Or as a further alternative the group of gripping elements may comprise two spaced double lugs each fitted with a locking screw and mounted slidingly in the axial direction along a sleeve in which the rod slides.  
  The tip is preferably fitted with a screwthread for fixing connections to the body, the body suitably being of moulded material and in the form of a hollow tube having an open end provided with a screwthread complementary to that of the tip. and at its opposite end a blocking wall, the needle protruding internally and externally and being anchored in the blocking wall, the hollow tubular body being adapted to receive a cartridge containing a dose of anaesthetic.  
  According to a further aspect of the invention there is provided a syringe body comprising a hollow tube having an open end fitted with means for fixture to a syringe head and at its opposite end a blocking wall. a needle which protrudes internally and externally being anchored in the blocking wall, the hollow tubular body being adapted to receive a cartridge containing a dose of anaesthetic.  
  The body of the syringe is supplied in sterile condition in a protective case constituted by a hollow tubular element which fits snugly upon the external face of the body, one end of said element being blocked by a solid wall, the length of the case being such that when the body in introduced therein the fixing means e.g. a screwthread of the latter remains free and the needle which protrudes outside the body is shielded in fluid tight relation inside the case without contact with the internal faces of the latter. The case may be provided internally with a stop which corresponds to a stop provided externally on the body so that the case enables the body when introduced therein to be driven in rotation in both directions.  
  Suitably the internal face of the case has a profile which is not of revolution corresponding to a similar profile of the external face of the body of the syringe.  
  According to yet a further aspect of the invention there is provided a cartridge containing a dose of anaesthetic comprising a tube of constant section fitted at one end with a fluid tight piston displaceable inside the tube and at the opposite end with a plug of elastic material comprising a first part fitting the interior of the tube and a second part external to the tube which covers the extreme portion of the latter and whose external dimension is greater than the internal dimension of the body of the syringe so that the plug exerts a friction force against the internal face of the body and opposes the free sliding of the cartridge in the body.  
  The first part of the plug fitting the interior of the tube of the cartridge may have thin walls such that said first part is crushed elastically by the pressure of the liquid in course of injection. In addition. the plug may have a blind cavity which opens at the exterior extreme face of the second part of said plug and which extends inside the first part.  
  The syringe of the present invention may be used with conventional anaesthetic cartridges having crimped joints. In such syringes suitably the rod slidingly mounted in the axial direction in the tip of the head is anchored in rotation with respect of said tip. the free end of said rod being provided with a screwthread which corresponds to the interior screwthread of the piston of conventional anaesthetic cartridges with a crimped joint.  
  The internal face of the body using in such a syringe may be fitted with lamellae which retain the cartridge in position.  
  The syringe bodies introduced into the cases and containing or not containing a cartridge of anaesthetic. and the cartridge supplied in sterile condition, may be supplied upon a sterilization and presentation support which comprises a base upon which is rests and a wall extending from the said base and de-limiting a cell adapted to receive. with friction and an air-tight seal an extreme part of one of the elements case or cartridge. said extreme part being. on a case containing a syringe body equipped with a cartridge. its free and open extreme part through which the screwthread of the syringe body protrudes. and on a cartridge alone, the extreme part opposite to that which is blocked by a piston.  
  In one embodiment there is provided a plurality of cells de-limited by walls rising from the said base.  
  Each cell may be provided with an internal stop which limits the insertion of the case or cartridge element.  
  Suitably an aperture is provided in the extreme blocking wall which carries the double needle.  
  In order that the invention may be more fully understood. embodiments in accordance therewith will now be described with reference to the accompanying drawings in which:  
 BRIEF DESCRIPTION OF THE DRAWINGS.  
  FIG. 1 is a vertical cross-section through a syringe fitted with a syringe body containing an anaesthetic cartridge and shielded by a protective case;  
  FIG. 2 is a vertical cross-section through a syringe body containing a cartridge prior to its assembly with the head of a syringe;  
  FIG. 3 is a section similar to FIG. 2, the case being arranged in a protective support;  
 FIG. 4 is a section along the line IVIV of FIG. 1;  
  FIG. 5 is a cross-section through a support with multiple cells for cases containing a syringe body and a cartridge with a syringe and a cartridge disposed in one cell;  
  FIGS. 6 and 7 are cross-section elevations showing a cartridge according to the invention and a conventional 4 cartridge each arranged on an individual support; and FIG. 8 is a cross-sectional elevation of a support with multiple cells for cartridges with a conventional cartridge provided with a piston with screwthread shown part in section.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS.  
  Referring to the drawings. FIG. 1 shows a hypodermic syringe with a syringe head designated by the reference 1, and a syringe body designated by the reference 2.  
  Only the head 1 is the permanent element, made of metal. which does not require to be sterilized and which the user may retain. Thehead comprises a tip 3 having at one end an internal screwthread and prolonged at the opposite end by a sleeve 4 in which a rod 5 slides.  
  .Upon the sleeve 4 there are stacked rings 6 clamped by a nut 7 which is screwed to the extreme terminal part of the sleeve.  
  Between the rings there are interposed two spaced discs 8 and 9 which have overall a frustoconical profile. one being flared towards the free end of the rod and the other in the opposite direction.  
  The rod 5 is provided at its end with a ring 10 large enough for the passage of a thumb.  
  The disc 9 and the ring 10 constitute a set of gripping elements which are used to give an injection, the index and second fingers being braced against the disc 9 while the thumb is engaged in the ring 10.  
  The gripping element fixed to the tip, that is to say the disc 9 can easily be moved along the sleeve 4 in order to regulate the distance of said elements as a function of the size of the operator&#39;s hand.  
  The disc 8, likewise adjustable in position. enables the syringe to be grasped more easily between the index and second fingers which may be slid between the two discs 8 and 9.  
  The syringe body 2 may be fabricated of moulded material for example of injection moulded plastics. It is supplied in sterile condition and intended to be disposable after use. It is constituted by a hollow tube having an open end fitted with a screwthread 11 complementary to that of the tip 3. The opposite end is closed by a transverse blocking wall 12 pierced with a rather small off-center hole 13.  
  In the wall 12, which is provided with a central reinforcement for this purpose. there is anchored a double needle which has an internally protruding part 14 and an externally protruding part 15.  
  The body 2 is protected for its delivery and its storage inside a case 16. The latter is a hollow tubular element mouled of plastic material, preferably of polyethylene, which fits snugly and air-tight upon the external face of the body. One end of the element is blocked by a solid wall 17. Its length is such that when the body is introduced into it. the screwthread 11 remains free whereas the entire remainder of the body including the needle 15 is shielded fluid tightly.  
  In the region of the reinforcement which retains the double needle, the body 2 is fitted externally with at least one stop 18. In this example. as FIG. 4 shows, there are four stops 18. The case 16 is fitted internally with four stops l9 situate in the same sectional plane as the stops l8.  
  The stops l8 and 19 come into contact as a result of a relative movement in rotation of the case and of the body. It is therefore possible to screw the body 2 onto the tip 3 by holding only the case 16, without having to disengage the body from it.  
  The same driving in rotation could be achieved by giving to the body 2 and to the case 16, or to a portion of these parts, a cross-sectional profile which is not of revolution about their common axis.  
  Referring to FIGS. 2 and 3 these show in detail cartridges containing an anaesthetic, which are generally supplied in sterile condition, arranged inside the body 2.  
  The cartridge of the invention. designated by the reference numeral 20, comprises a tube 21 of constant section fitted at one end with a fluid piston 22 displaceable inside the tube and provided at its opposite end with a plug 23 of elastic material, for exampleof rub ber.  
  The plug 23 comprises a first part 24 fitting the interior of the tube and a second part 23 exterior to the tube 21. Said second part 25 covers the extreme portion of the tube 21 and it has externally a dimension for example a diameter which is greater than the interior dimension of the body of the syringe.  
  A blind cavity 26 is provided in the plug 23; it opens into the exterior extreme face of the second part 25 and extends inside the first part 24 of the said plug. Thus. the walls of the first part 24 are reduced in thickness and they are capable of being crushed elastically upon themselves. With a plug fabricated ofa sufficiently flexible elastomer. it would not be necessary to reduce in thickness the walls of the first part 24 to obtain an elastic crushing of this part of the plug.  
  When a cartridge 20 is introduced into the interior of the body 2, the plug 23 leading, by virtue of the friction of the latter against the internal face of the body. the said cartridge remains in the position in which it is placed.  
  Before the syringe body is assembled upon the syringe head, the case-body-cartridge assembly is in the state visible in FIG. 2. The cartridge 20 is anchored in the body 2 by virtue of the friction of the plug 23, at such a depth that the latter is not perforated by the interior part 14 of the needle.  
  In order tosupply and maintain the said assembly in sterile condition. according to the invention a support 27 is provided for use individually (FIG. 3) or grouped with others so as to constitute a multiple celled support (FIG. 5).  
  Each support 27 comprises a base 28 upon which it rests and a wall (FIG. 3) or a plurality of mutually adjacent walls (FIG. 5) which rise from the base and limit one or more cells. The latter are adapted to receive with friction and air-tightly an extreme part of a case containing a body and a cartridge or a body alone.  
  It is possible to provide supports of smaller size adapted to receive in the same fluid tight manner an extreme part of a cartridge according to the invention (FIG. 6) or a conventional cartridge (FIGS. 7 and 8) either individually or in a group.  
  The cartridges 20 of the invention and the conventional cartridges are introduced into their supports by their plug or by their crimped joint which must be pierced by the interior needle 14 of the syringe body.  
  An internal shoulder or stop limits to an appropriate value the insertion of the cartridges into their supports: the same may apply to the cases. I  
  When the cases are fabricated of polyethylene. the supports are preferably made of polystyrene, since the contactof these two materials achieves a better fluid tight seal then the contact of identical materials. Furthermore. polyethylene is permeable to ethylene oxide whereas polystyrene is not. Therefore the interior of a complete block like those in FIG. 3 orin FIG; 5 can be sterilized before their assembly. by placing them in an atmosphere of ethylene oxide under pressure. The gas passes through the wall of the case 16, spreads in the support 27 and in the body 2 through the lower aperture and through the upper aperture 13.  
  The supports and the blocks of supports of the invention ensure durably and with certainty the sterility on the one hand of the syringe body and the cartridge, and on the other hand of the plug which will be pierced by the needle.  
  A single movement of the hand is sufficient to take a case-body-cartridge assembly or a cartridge along without having to undertake an additional sterilization.  
  When an assembly in the state visible in FIG. 2 has been grasped and withdrawn from its support the body 2 is screwed into the tip 3 as stated hereinbefore.  
  During the screwing, the cartridge 20 is constrained to descend into the body of the syringe and the plug 23 is pierced by the internal needle 14.  
  At the end of stroke of the screwing, the extreme portion of the tube 21 crushes the external part 25 of the plug against the internal face of the wall 12. Said crushing ensures fluid tightness at the end of the cartridge and of the body.  
  The case is then withdrawn by a simple sliding movement along the body 2, and the syringe is ready for use.  
  When a force is exerted upon the rod 5, the piston 22 is thrust into the cartridge; the liquid which it contains is placed under pressure and the interior part 24 of the plug which receives the said pressure is elastically compressed, diminishing in height. If at this moment the force exerted upon the rod 5 is relaxed, then the interior part 24 of the plug expands, repels the liquid of the cartridge and thus produces a suction. The latter is weak but is is sufficient to verify whether the tip of the needle 15 has stopped in a blood vessel.  
  To perform a second injection with the same syringe body, the case 16 is taken once more, the body 2 is unscrewed, the empty cartridge is thrown away and is replaced by a full cartridge which is extracted from its support and which is introduced into the body 2, as in FIG. 2, without having to grasp it by the plug which must remain sterile.  
  In order to dispose of the body of the syringe when it has been unscrewed from the tip by means of the case 16, the latter is not withdrawn. In this manner the point 15 which could wound or contaminate remains enclosed in the case.  
  The invention permits the use of a conventional cartridge 29 which has, at its end opposite to the piston 30, a shrinkage 31; the latter serves to fit a crimping capsule 32 with a central orifice which maintains in position a fluid tight seal 33. Some pistons 30 have a screwthreaded blind hole 34.  
  In this case the free end of the rod 5 is screwthreaded like the hole 34 and the rod itself is anchored in rotation inside the sleeve 4 by virtue of a groove and of a lug (not shown). The internal face of the syringe body is equipped with longitudinal lamellae (not shown) which oppose the rotation of the cartridge 29 and which also brake its translation inside the body.  
  During the screwing of the tip 3 and of the body 2. the rod 5 is screwed in the plug 30. This permits the verifying suction discussed hereinbefore to be effected by a traction applied to the rod 5.  
  The present invention also embraces those modifications and variants which do not depart from its ambit or from its spirit. The syringe illustrated and described is adapted for use by dentists. but it will be apparent that it is also suitable for other uses.  
  For example. the use of a double claw or of a double lug equipped with a locking screw will be considered an equivalent means to the discs 8, 9 and to the rings 6. The said screws serve to anchor the lug at the desired point along the sleeve 4.  
 I claim:  
 1. A hypodermic syringe comprising:  
 a syringe head including a tip having an axial bore extending therethrough a hollow sterile syringe body connected to said head.  
 a rod slidably mounted in said bore in said head and including a portion extending externally of said head.  
 a gripping element fixed to said portion of the rod extending externally of the head.  
 a counter-gripping element. means mounted on said head for adjustably securing said counter-gripping 8 element thereto in an axially adjustable position with respect to said gripping element on said rod, means in said body for storing an injectible solution and operated by displacement of said rod,  
 and means for dispensing said solution from said body.  
 said tip comprising an elongated sleeve in which the rod slides. said means for adjustably securing said gripping element comprising a set of rings stacked on the said sleeve. locking means for locking the rings in the axial direction fitted at one end of the sleeve, said counter-gripping element being constituted by a disc interposed between two rings of said set of rings, said locking means being demountable to enable the disc to be interposed between any two other rings.  
  2. A syringe as claimed in claim 1, comprising a second disc interposed between said rings of said set at a point remote from the first disc.  
  &#39;3. A syringe as claimed in claim 1, comprising a second disc interposed between said rings of said set at a point remote from the first disc. the two said discs having a frustoconical profile, one being flared towards the gripping element fixed to the rod and the other being flared in the opposite direction.  
  4. A syringe as claimed in claim 1, wherein said locking means comprises a nut screwed onto said sleeve to hold the counter-gripping element and set of rings on said sleeve.