in fig1 a single - use application device according to the invention is shown in perspective view and depicted in total with reference numeral 10 . the application device 10 comprises a tubular receptacle 12 which is configured as a glass cylinder , having a first longitudinal end 13 and a second longitudinal end 14 and enclosing a cavity 15 that can be filled with a liquid . the cavity 15 is sealed to the outside by a piston 18 held at the end of a piston rod 20 and sealed against the interior wall of the cavity 15 by suitable sealing rings ( not shown ). the application device 10 is shown in fig1 in its closed state in which the cavity 15 is sealed against a needle supported on the first tubular end 13 of the tubular receptacle 12 and surrounded by a collar 24 and an attached cap 22 . for transferring the application device 10 from its closed state shown in fig1 to an open state in which a liquid can be injected through the needle 32 shown in fig2 and 3 , merely the cap 22 needs to be removed and thereafter the piston 22 can be advanced within the cavity 15 by pressing the end of the piston rod 20 with one finger while holding the tubular receptacle 12 at a gripping flange 16 provided on the second longitudinal end 14 with two fingers . the details of the application device that allow a sealing of the cavity 15 against the needle 32 when being in its closed ( or “ dry ”) state and for transferring the application device into its open state in which liquid stored within the cavity 15 can be injected through a tip 38 of the needle 32 will be explained hereinafter with reference to fig2 and 3 . according to fig2 the tubular receptacle 12 comprises a tubular extension 45 having a smaller diameter than the reminder of the tubular receptacle 12 and being connected to the remainder of the tubular receptacle 12 by a neck portion 44 defining a circumferential recess . held within the inner wall of the tubular extension 45 is a bung 46 made of a polypropylene material or from tpe . the bung is of generally cylindrical shape resting with a peripheral flange 50 against the end surface of the tubular extension 45 and having a central through channel 48 that opens into the cavity 15 at one end and opens into a delivery duct 36 of the needle 32 at the other end . in fig3 the bung 46 is shown in its released state so that the central through channel 48 is not blocked by a pinch seal effected in the closed state shown in fig2 . a holder 26 preferably made of a hard but elastic plastic material is attached onto the outer surface of the bung 46 and comprises an enlarged portion 40 having a larger outer diameter with a hollow tubular portion 41 that is fitted onto the peripheral flange 50 of the bung 46 and onto the tubular extension 45 of the tubular receptacle 12 , thereby pressing the peripheral flange 50 of the bung 46 against the tubular extension of the receptacle 12 . to effect a proper securement , the enlarged portion 40 comprises an inner rim portion 42 at its end remote from the needle 32 engaging the neck portion 44 of the tubular receptacle 12 . to finally secure the holder 26 against removal from the tubular receptacle 12 , in addition , a collar 24 is pressed onto the peripheral wall of the enlarged portion 40 using a press fit and rests against a rim portion protruding outwardly at the end of the enlarged portion 40 . the needle 32 , usually made of stainless steel is fitted into a central opening 28 of the holder 26 and secured by an adhesive 30 or by another means so that the inner end of the needle 32 rests about flush with the through channel 48 of the bung 46 . the holder 26 at one side comprises a flexible arm 34 extending from a portion near the inner end of the needle 32 and having a free end remote from the needle 32 . the flexible arm 34 has a cross section of a wedged shape having a larger thickness at its free end than at its other end that is connected to the remainder of the holder 26 . the holder 26 is made from a hard but elastic plastic material that allows to bias the flexible arm 34 into the position shown in fig3 so that the bung 46 is not compressed in the open state indicated by numeral 10 ′ in fig3 . for transferring the application device into a closed state in which the central through channel 48 of the bung 46 is sealed by the pinch seal 52 as shown in fig2 , the cap 22 needs to be attached on the holder 26 . the cap 22 is inserted onto a peripheral portion of the holder 26 resting with its end within a slot provided between the peripheral portion of the holder 26 and the collar 54 and abutting against the enlarged portion 40 of the holder 26 . in this closed state shown in fig2 the flexible arm 34 is pressed by the cap 22 to the inside against the bung 46 thereby effecting the pinch seal 52 of the through channel 48 , whereby the through channel 48 is effectively blocked . this closed state shown in fig2 is the ready - to - use state of the application device filled for instance with a medical drug by a drug manufacturer . the liquid containing the drug solution within cavity 15 is sealed against the needle 32 by the pinch seal 52 . when the application device needs to be used , merely the cap 22 is pulled off from the holder 26 while holding the application device at the tubular receptacle 12 . once the cap 22 is removed , as shown in fig3 , the flexible arm 34 flexes to the outside under its own bias thereby releasing the central through channel 48 so that the drug solution contained in cavity 15 may then ejected out of the needle tip 38 by advancing the piston rod 20 thereby expelling the drug solution through the needle tip 38 . in case after a long storage period there should be some tendency of sticking between the two adjacent parts of the inner wall of the bung 46 effecting the pinch seal 52 , the pressure generated by advancing the piston 18 into the cavity 15 will effectively remove any potential blockage of the pinch seal 52 . alternatively , or in addition , the inner wall surface of the bung may comprise a coating ( not shown ) that is made from a material that prevents sticking and that prevents interaction with any drug material . such a coating may , e . g . consist of parylene of ptfe ( polytretrafluorethylene ). this leads to a very reliable design .
an application device for applying a dispensable material is disclosed having a closed state and an open state , the application device comprising an elastic part made of an elastic material and having a through channel being configured for engaging a cavity of a receptacle , further comprising a holder supporting a dispensing means fluidly connected with the through channel . a pinch seal is used for sealing the through channel when being in the closed state . long - term storage is made possible , since leakage of the pinch seal is prevented by a cap effecting the pinch seal which is partially fitted into a collar .