Patent Publication Number: US-2023149639-A1

Title: A syringe, a method for manufacturing such syringes and an assembly

Description:
TECHNICAL FIELD 
     The present invention relates to a syringe according to the introductory portion of the attached claim  1 . The present invention further relates to a method according to the attached claim  13  for manufacturing such syringes. Still further, the present invention relates to an assembly according to the attached claim  15 . 
     BACKGROUND 
     A general problem associated with syringes, especially those intended for self-injecting insulin into diabetes patients, is that they are quite expensive and also extensive and, thus, not easy to handle and to carry with you, e.g. in a pocket, a bathing suit and the like, and, thus, not easy to use discretely. 
     Yet another general problem associated with syringes, especially those intended for injecting substances, e.g. a liquid comprising insulin, into the human body, is that it is normally preferable that they are intended for single injection purposes, this being for contamination reasons. Thus, well known are the extremely serious problems associated with re-use of syringes as a source of spread of infections. 
     Further, there is a problem to design a convenient and practical housing for one or more syringes according to the present invention. 
     Still further, there is a problem to manufacture syringes according to the present invention in large numbers to a reasonable cost, the need of syringes being most extensive. 
     PRIOR ART 
     Therefore, there are a great number of prior art syringes being designed to prevent re-use, these designs being, however, complicated, expensive to manufacture and complicated to mount. 
     The object of the present invention is to provide a syringe less associated with the problems related to prior art syringes and yet, in principle, avoiding re-use possibilities. 
     Further, an object of the present invention is to provide a design and method for manufacturing syringes according to the present invention in large numbers to a low cost. 
     SUMMARY OF THE INVENTION 
     These and other objects are obtained by a syringe according to what is specified in independent claim  1  as well as by a method according to what is specified in independent claim  13  and an assembly according to independent claim  15 . 
     Further objects are obtained by what is specified in the dependent claims. 
     According to preferred embodiments, the size of the syringe is quite limited so as to provide comparatively discrete injecting and comfortable carrying in even quite tight or tapered clothes. Thus, according preferred embodiments the syringe, with the plunger fully drawn out, has a length in the range of 30-80 millimeters, preferably in the range of 40-60 millimeters. 
     Further, according to preferred embodiments, the size of the syringe is adapted to the kind of liquid to be injected, e.g. the concentration of the active substance of the liquid, which means that a larger volume of liquid is desired and therefore a bigger size of the syringe is necessary for obtaining a desired effect of a certain injection. 
     According to preferred embodiments the rear end of the plunger has a conical flange portion, narrowing towards the plunger front end and forming an edge portion running around the plunger rear end. In this way gripping is promoted. 
     According to preferred embodiments the rear end of the container is formed with a countersink arrangement to receive the rear end of the plunger. In this way the rear end of the plunger is fitted in the end portion of the container in the discharged state of the syringe so that gripping of the plunger rear end, in practice, is prevented, the end portion having a convex configuration to provide a hard to grip shape. 
     According to preferred embodiments said coupling portion front has a convex rounded configuration and a rear, substantially cylindrical, support portion. In this way the introduction into said cavity as well as the coupling action and the movability in the cavity is promoted. 
     According to preferred embodiments the piston portion is made of a resilient material, such as a rubber based material or a polymeric material. In this way a liquid tight connection with the container as well as mounting on the coupling portion is promoted. 
     According to preferred embodiments the syringe is substantially axially symmetrical. This makes the syringe easy to handle and to manufacture. 
     According to preferred embodiments an end portion of the plunger is provided with a rearward open channel like recess intended to receive a mounting pin of a mounting assembly, the mounting pin being intended to support syringe parts during mounting of the syringe, whereby a very efficient mounting procedure may be obtained for a large number of syringes at a low cost. 
     According to preferred embodiments the front portion with the needle is covered and, thus, protected during handling and transportation by a potential user by a cover in the form of a sleeve with a front wall and an open rear end portion, the cover being designed to be removably applied to said front portion and held by internal friction against an internal ridge, the cover being made of a resilient material other than the material of the front portion. The cover has a cylindrical rear portion running from an outer stop flange, the rear portion being intended to fit in a syringe housing, and being held by an external ridge. In this way syringes may be handled liquid tightly disposed in said housing and handled liquid tightly protected by said cover when removed from said housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A better understanding of the present invention may be had by considering the following detailed description in conjunction with the attached drawings, in which like details are designated with like designations and in which: 
         FIG.  1    diagramatically shows in a) a syringe unit comprising a needle, a front portion and a container, in b) a needle cover, in c) a piston with a rear recess and in d) a plunger portion; 
         FIG.  2    shows two projections of a single syringe housing; 
         FIG.  3    shows two projections of a three syringe housing; 
         FIG.  4    shows, in cross section, a single syringe housing containing a syringe shown in a delivery state and, thus, not yet filled with liquid; 
         FIG.  5    shows, in cross section, a three syringe housing containing three syringes, the bottom one being fully discharged and the middle and the top ones being filled with liquid and ready for discharging said liquid; 
         FIG.  6    shows, in cross section, a mounting pin; 
         FIG.  7     a )- e ) show five different stages of mounting of syringes in a mounting assembly, wherein five groups of four syringes held in a syringe row are shown to the left and, in different stages of mounting, five groups of four mounting pins arranged for performing different mounting steps are shown to the right; 
         FIG.  8     a )- e ) show four different states of syringe use, a) showing a delivery state, b) showing a state wherein liquid being sucked into the syringe, c) showing a state wherein the syringe is ready for discharging said liquid, d) showing a state wherein the syringe is only partly filled with liquid and e) showing a discharged state; and 
         FIG.  9    schematically shows an assembly according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     According to the embodiment shown in separate parts in  FIG.  1   a   )- d ), the syringe  10  comprises a front portion  11  carrying a hollow, axially extending needle  12  indicated in the Figs, a container  13 , running from said front portion  11  and forming a container rear end portion  14 . There are several different arrangements for applying said needle  12  at the front portion  11 . According to one embodiment the needle is connected to a sleeve portion arranged to be force fit onto said front portion. According to another embodiment the needle is connected to a sleeve portion arranged to be screwed onto said front portion and thereby being fastened by a thread like arrangement. 
     The syringe further comprises a plunger  15 , extending and being movable axially in the container  13 , the needle rear end  16  being in fluid connection with the container and the plunger being arranged to suck liquid through the needle when drawn away from the needle and to discharge liquid through the needle when pushed towards the needle. 
     The plunger has a piston portion  17 , turned to the needle rear end, and a coupling portion  18  arranged to co-act with the piston portion for moving the piston portion in the container. The piston portion and the plunger body  15 ′ comprising the coupling portion are separate parts, the piston portion being connected to the plunger body by means of the coupling portion. 
     Thus, the coupling portion is introduced into a cavity  19  in the piston portion and is movable axially in said cavity between a front position and a rear position, the plunger length in relation to the container length being adapted so that when the syringe is arranged in a delivery state,  FIG.  8   a   ), with the piston portion in a front position in the container and with the coupling portion in said rear position in said cavity, the rear end  15 ″ of the plunger is extending a certain distance beyond the rear end portion  14  of the container, thereby forming a plunger gripping portion  15 ′″. 
     Further, the container rear end portion  14  comprises an internal locking flange arrangement  20  and the plunger portion  15 ″ extending a certain distance beyond the container rear end portion comprises an outer locking flange arrangement  21 , so that when the plunger in a discharged state,  FIG.  8   e   ), is pushed forward to the front position of the coupling portion in said cavity, the locking flange arrangement of the plunger is pushed forward, passing the locking flange arrangement of the container, thereby locking the plunger in the container in a non re-use state of the syringe. 
     According to preferred embodiments the rear end gripping portion  15 ′″ of the plunger has a flange portion  22  forming an edge portion  22 ′ of the plunger rear end. 
     According to preferred embodiments the rear end  14  of the container is formed with a countersink arrangement  23  to receive the rear end gripping portion  15 ′″ of the plunger in a discharged state of the syringe, thus making the end  15 ″ extremely hard or even impossible to grip, as can be seen in  FIG.  8   e   )). 
     Further according to preferred embodiments, said coupling portion  18  has a front convex and rounded tip configuration  24 , to promote introduction into said cavity and its coupling action for passing a rear stop flange  19 ′ of the piston portion, and a rear, substantially cylindrical, support portion  25  to pass into and out of said cavity. 
     Preferred is also that the piston portion is made of a resilient material, such as a rubber based material or polymeric material, the piston portion being axially longer than the inner diameter of the container in order to prevent tilting in the container. To promote low friction the front, rear and middle of the piston portion are designed as flanges  17 ′. 
     Further, according to preferred embodiments, the syringe is substantially axially symmetrical. 
     Further, the piston body  15 ′ front end, from which the coupling portion is extending, comprises a flange arrangement  28 , which is intended to co-act with the flange arrangement  20  of the container when the plunger is pulled backwards and thus preventing the plunger from leaving the container. 
     According to preferred embodiments the front portion with the needle is covered and, thus, protected during handling and transportation by a potential user by a cover  29  in the form of a sleeve with a front wall  29 ′ and an open rear end  29 ″ portion, the cover being designed to be removably applied to said front portion and held by internal friction against an internal ridge  29 ′″, the cover being made of a resilient material other than the material of the front portion. The cover has a cylindrical rear portion running from an outer stop flange  30 , the rear portion being intended to fit in a syringe housing  31 , 32  as shown in  FIG.  4  or  7   , and being held by an external ridge  29 ″″. 
     According to preferred embodiments there are housings provided for one or more syringes for protection during transport, carrying and handling of the syringes, the housing for more than one, for example three, syringes providing a record for the number of syringes used for injection by the user, used syringes preferably being returned into the housing. 
     According to preferred embodiments an end of the plunger  15  is provided with a rearward open channel like recess  33 ,  FIG.  1   , intended to receive a mounting pin  34 ,  FIG.  6   , of a mounting assembly  40 , the mounting assembly being, described later in association with  FIG.  7   , the mounting pin being intended to support syringe parts during mounting of the syringe. 
     The function of the syringe according to the present invention should to a considerable and sufficient extent have been made clear by the description given above. 
     Thus, in a delivery state,  FIG.  8   a   ), the syringe is arranged with the piston portion in a front position in the container and with the coupling portion  18  in said rear position in said cavity, the rear end  15 ″ of the plunger extending a certain distance beyond the rear end  14  of the container, thereby forming a plunger gripping portion  15 ′″. 
     To fill the syringe the needle is introduced into a liquid, e.g. a liquid comprising insulin, glycagon, a vaccine or other substances, the plunger is pulled backwards in the container, whereby the liquid is sucked into the container through the needle by the piston portion drawn by the coupling portion to fill the container to a desired extent. 
     To discharge liquid from the syringe to empty it through the needle, the plunger is pushed forward in the container. The coupling portion is pushed forward to the front position in said cavity and the locking flange arrangement of the plunger is pushed forward, passing the locking flange arrangement of the container, thereby locking the plunger in the container in a non re-use state of the syringe. 
     According to the preferred embodiments the countersink arrangement of the container rear end receives the rear end gripping portion ( 15 ′″) of the plunger, thus making it extremely difficult or impossible to draw the plunger backwards again to re-use the syringe. 
     An important part of the present invention is also a method for manufacturing syringes according to the present invention, the syringes, in general terms, having a front portion ( 11 ) carrying a hollow, axially extending needle ( 12 ), a container ( 13 ), running from said front portion and forming a container rear end portion ( 14 ), a plunger ( 15 ), extending and being movable axially in the container, the needle rear end ( 16 ) being in fluid connection with the container and the plunger being arranged to suck liquid, e.g. a liquid comprising insulin, glycagon, a vaccine or other substances, through the needle when drawn away from the needle and to discharge liquid through the needle when pushed towards the needle, the plunger having a piston portion ( 17 ), turned to the needle rear end, and a coupling portion ( 18 ) arranged to co-act with the piston portion for moving the piston portion in the container. 
     According to preferred embodiments the method comprises the steps of
         providing the plunger  15  with a channel like, axially running recess  33 ,  FIG.  1   c   ), having a rear opening and being intended to receive a mounting pin  34  for supporting syringe parts  15 , 19  during mounting of the syringe;   providing a unit  35  comprising said container  13  with the needle  12  arranged in the front portion  11 ,  FIG.  7   a   ) and holding said unit in a mounting position and carrying the piston portion  19  by means of the mounting pin,  FIG.  7   a   );   introducing the piston portion  19  in the container by means of the mounting pin,  FIG.  7   b   );   carrying the plunger by means of the mounting pin,  FIG.  7   c   );   introducing the coupling portion  18  of the plunger into the piston portion for co-action for moving the piston portion forward and backwards in the container by means of the mounting pin,  FIG.  7   d   ), and   bringing the syringe into a delivery state by removing the mounting pin,  FIG.  7   e   ).       

     The steps are illustrated in Figs. a)-e). 
     According to preferred embodiments of a mounting assembly  40  according to the present invention, a desired number of mounting pins are arranged on a mounting frame  36 , movable to and from syringe units  35  held and carried by a syringe unit frame  37  for performing the necessary steps of the method according to the present invention. Of course the four syringes being mounted in  FIG.  7    is only an example, the number being intended to be much greater. 
     Above the present invention has been described in association with preferred embodiments and examples. Of course, further embodiments as well as minor changes and additional details may be imagined without departing from the basic inventive idea of the present invention. 
     Further, according to preferred embodiments, the container and the plunger are made of polymeric material. 
     Thus, the present invention is not limited to the embodiments shown but may be varied within the scope of the attached claims.