Cylinder-piston unit with short cannula

Patent metadata

Field	Value
Publication number	US-9599220-B2
Application number	US-201414276249-A
Country	US
Kind code	B2
Filing date	May 13, 2014
Priority date	Nov 16, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A cylinder-piston unit, with at least one cylinder accommodating an injection solution and having an outlet opening, and with at least one piston. The cylinder, or a component mounted upstream of the cylinder, has an end face from which, during correct emptying of the cylinder-piston unit, a short cannula protrudes, which has an outlet opening at its free end. The outlet opening has a surface with a border which has a point near the bottom or an edge near the bottom. The point near the bottom or the edge near the bottom lies 0.15-0.3 mm away from the end face or the front-most point or edge thereof. A cylinder-piston unit is developed which is intended for a disposable injector and which is suitable for virtually painless penetration of the human skin, among other reasons for the administration of highly viscous injection solutions.

First claim

What is claimed is:

1. Cylinder-piston unit ( 10 ), with at least one cylinder ( 20 ) accommodating an injection solution ( 1 ) and having an outlet opening ( 71 ), and with at least one piston ( 80 ), a piston actuating rain ( 7 ) actuating the at least one piston ( 80 ), the improvement which comprises:
the cylinder ( 20 ) has a bottom portion ( 33 ), on which a short cannula ( 61 ) is arranged congruent to the centre line ( 5 ) of the cylinder-piston unit ( 10 ), the bottom portion ( 33 ) of the cylinder ( 20 ) has a front end face ( 46 ),
an elastomer adhesive disc ( 110 ), which is displaceable in the direction of a center line ( 5 ) of the cylinder-piston unit ( 10 ) between and an installation position ( 111 ) and an application position ( 112 ) is slidably arranged on the short cannula ( 61 ) and/or on the bottom portion ( 33 ), the bottom portion ( 33 ) has an annular web ( 51 ), which extends forward in a continuation of the outer wall ( 32 ) of the cylinder ( 20 ), the annular web ( 51 ) encloses a receiving space ( 53 ) for the elastomer disc ( 110 ), the elastomer disc ( 110 ) slidable within the receiving space ( 53 ), the elastomer disc ( 110 ) in the installation position ( 111 ) occupying a front area of the receiving space ( 53 ) and the short cannula ( 61 ) penetrating a predetermined portion of the elastomer disc ( 110 ), but not fully through the elastomer disc ( 110 ), in the application position ( 112 ) the elastomer disc ( 110 ) fully occupying the receiving space ( 53 ), the elastomer disc ( 110 ) in the application position ( 112 ) bearing on the front end face ( 46 ) of the bottom portion ( 33 ) and simultaneously protruding a predetermined distance beyond the annular web ( 51 ),
the elastomer disc ( 110 ) having an end face ( 113 ) mounted upstream of the cylinder ( 20 ), from which, during correct emptying of the cylinder-piston unit ( 10 ) in the application position ( 112 ), the short cannula ( 61 ) protrudes, the short cannula ( 61 ) has an outlet opening ( 71 ) at its free end, the short cannula ( 61 ) in fluid communication with the cylinder ( 20 );
the outlet opening ( 71 ) has a surface with a border ( 72 ) which has a point ( 74 ) near the bottom or an edge ( 76 ) near the bottom, and
the point ( 74 ) near the bottom or the edge ( 76 ) near the bottom lies 0.15-0.3 mm away from the end face ( 113 ) of the elastomer disc ( 110 ) or the front-most point or edge ( 44 ) thereof.

2. Cylinder-piston unit according to claim 1 , wherein a through-flow cross section of the short cannula ( 61 ) lies in a range of 0.03 to 0.1 mm 2 .

3. Cylinder-piston unit according to claim 1 , wherein the short cannula ( 61 ) has, at the front, a single cut with a short bevel design in accordance with DIN 13097-4 of August 2009.

4. Cylinder-piston unit according to claim 1 , wherein the elastomer disc ( 110 ), in the installation position ( 111 ), has a sealing area ( 117 ) for closing the outlet opening ( 71 ) of the short cannula ( 61 ), the effect of which sealing area is no longer present in the application position ( 112 ).

5. Cylinder-piston unit according to claim 1 , wherein the elastomer disc ( 110 ) has an adhesive coating ( 121 ) on the end face ( 113 ) directed away from the bottom portion ( 33 ) of the cylinder ( 20 ), the adhesive elastomer disc ( 110 ) detachable from the short cannula ( 61 ) in the application position ( 112 ) after an injection of the injection solution ( 1 ).

Assignees

• Matusch Rudolf
• Lts Lohmann Therapie Systeme Ag

Inventors

• Matusch Rudolf

Classifications

• F16J1/005 Primary

  obtained by assembling several pieces · CPC title

• A61M5/46 Primary

  having means for controlling depth of insertion · CPC title