Disposable injector with increased triggering reliability

Patent metadata

Field	Value
Publication number	US-10888658-B2
Application number	US-201715793295-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	May 4, 2015
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A disposable injector with a piston actuation ram is mounted in a housing, is loaded by a spring energy accumulator and can be unlocked by a displaceable trigger device. The piston actuation ram can be supported by a tensioning rod mounted in the housing. The trigger device comprises a trigger ring displaceable relative to the housing. The tensioning rod can be supported directly or indirectly by a bearing surface of the trigger ring. The bearing surface encloses an angle of between ten degrees and forty five degrees with the longitudinal direction of the disposable injector. The point of the angle lies offset with respect to the trigger ring in the triggering direction of the disposable injector. A disposable injector with increased trigger reliability is developed.

First claim

What is claimed is:

1. A disposable injector ( 4 ) having a longitudinal center axis ( 7 ) and having a piston actuation ram ( 60 ) which is supported in an inner tubular a housing ( 10 ) and which is loaded by a resilient energy store ( 50 ) comprising a helical compression spring and which can be unlocked by a displaceable triggering device ( 80 ), characterized in that
the piston actuation ram ( 60 ) including an elongated cylindrical guiding journal ( 62 ) configured in an operative position to axially extend through and carry the helical compression spring ( 50 ), a disk-like ram plate ( 73 ) configured to retain the helical compression spring ( 50 ) on the elongated cylindrical guiding journal ( 62 ) operatively attached to the disk-like ram plate ( 73 ), a rod-like piston sliding member ( 76 ) operatively configured to operatively engage a cylinder/piston unit ( 100 ),
a tensile locking rod ( 21 ) configured to support the piston actuation ram ( 60 ), the tensile locking rod ( 21 ) having a U-shape and consisting of a straight main member ( 27 ) and an integral clamping member ( 25 ) at one end of the straight main member ( 27 ) extending perpendicularly to the straight main member ( 27 ) and an integral wrap-around hook ( 26 ) at another end of the straight main member ( 27 ) having a predetermined curvature extending from the straight main member ( 27 ),
the inner tubular housing ( 10 ) having a cylindrical basic shape and including an exterior surface elongated flattened portion ( 14 ) of predetermined length having a first slot-like aperture ( 16 ) proximate one end of the exterior surface elongated flattened portion ( 14 ) and a second slot-like aperture ( 18 ) proximate another end of the exterior surface elongated flatted portion ( 14 ), the straight main member ( 27 ) in the operative position configured to be carried on the exterior surface elongated flattened portion ( 14 ), the clamping member ( 25 ) configured in the operative position to pass through the first slot-like aperture ( 16 ) for clamping an end of the helical compression spring ( 50 ), the wrap-around hook ( 26 ) configured in the operative position to pass through the second slot-like aperture ( 18 ) and configured to grasp the disk like ram plate ( 73 ) to lock the piston actuation ram ( 60 ) and to lock the helical compression spring ( 50 ) in a compressed state prior to triggering of the disposable injector ( 4 ) and configured upon triggering by the displaceable triggering device ( 80 ) to expand outwardly away from the longitudinal center axis ( 7 ) and away from the second slot-like aperture ( 18 ),
the displaceable triggering device ( 80 ) comprising a triggering sleeve covering housing ( 82 ) which can be displaced relative to the inner tubular housing ( 10 ),
a displaceable triggering ring ( 190 ) displaceably arranged on the inner tubular housing ( 10 ) and supported by the triggering sleeve covering housing ( 82 ), the displaceable trigger ring ( 190 ) having a cylindrical inner wall ( 193 ) having an oblique abutment face ( 195 ) terminating at a lower shoulder ( 197 ) of the displaceable triggering ring ( 190 ), the oblique abutment face ( 195 ) facing inwardly and configured to retain and compress the wrap around hook ( 26 ) of the tensile locking rod ( 21 ) in the operative position in the slot-like aperture ( 18 ) to lock the ram ( 60 ) prior to an actuation of the triggering sleeve covering housing ( 82 ), the triggering sleeve covering housing ( 82 ), upon actuation of the triggering sleeve covering housing ( 82 ), configured to displace the displaceable triggering ring ( 190 ) longitudinally relative to the inner housing ( 10 ) and to simultaneously cause the tensile locking rod ( 21 ) in cooperation with the oblique abutment face ( 195 ) to slide outwardly and to release the compressed wrap-around hook ( 26 ), the grasped disk-like plate ( 73 ) and the helical compression spring ( 50 ),
the inwardly facing oblique abutment face ( 195 ) of the triggering ring ( 190 ) defines, with a longitudinal direction ( 5 ) of the disposable injector ( 4 ), a predetermined angle, wherein the apex of the predetermined angle is in a triggering direction ( 6 ) of the disposable injector ( 4 ) and is located offset with respect to the triggering ring ( 190 ).

2. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that the triggering ring ( 190 ) and the inner tubular housing ( 10 ) are constructed so as to be rotationally secure with respect to each other.

3. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that the oblique abutment face ( 195 ) carries a sliding plate ( 196 ).

4. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that the tensile locking rod ( 21 ) is constructed as a single sheet metal strip.

5. The disposable injector ( 4 ) as claimed in claim 4 , characterized in that the tensile locking rod ( 21 ) comprises austenitic spring steel with a predetermined elasticity modulus.

6. The disposable injector ( 4 ) as claimed in claim 5 , characterized in that the predetermined elasticity modulus is greater than 190,000 Newton per square millimeter.

7. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that the clamping member ( 25 ) is fixed in the inner tubular housing ( 10 ) by a support screw ( 12 ) which is secured in the inner tubular housing ( 10 ).

8. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that a relative movement between the displaceable triggering device ( 80 ) and the inner tubular housing ( 10 ) can be blocked by a releasable or unlockable securing element ( 87 ).

9. The disposable injector ( 4 ) as claimed in claim 1 , characterized in that the predetermined angle is between 10 degrees and 45 degrees.

Assignees

• Lts Lohmann Therapie Systeme Ag

Inventors

• Forghani Sara
• Wortmann Uwe
• Heuser Karsten
• Spilgies Heiko

Classifications

• A61M5/2033 Primary

  Spring-loaded one-shot injectors with or without automatic needle insertion (multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287) · CPC title

• A61M5/3158 Primary

  performed by axially moving actuator operated by user, e.g. an injection button · CPC title

• A61M2005/2073

  preventing premature release, e.g. by making use of a safety lock · CPC title