Single-use injector having a flexurally elastic housing

• US 8,105,271 B2
• Filed: 06/15/2011
• Issued: 01/31/2012
• Est. Priority Date: 12/18/2008
• Status: Active Grant

• Current Assignee: LTS Lohmann Therapie-Systeme AG
• Original Assignee: LTS Lohmann Therapie-Systeme AG
• Inventors: Matusch, Rudolf
• Primary Examiner(s): Lucchesi, Nicholas
• Assistant Examiner(s): FLICK, JASON E
• Application Number:
  US13/134,721
• Publication Number:
  US 20110251549A1
• Time in Patent Office: 230 Days
• Field of Search: 604/68
• US Class Current: 604/68
• CPC Class Codes: A61M 2005/2013 triggering of discharging means by contact of injector with patient body
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 2005/312 comprising sealing means, e.g. severable caps, to be removed prior to injection by, e.g. tearing or twisting
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules

Abstract

A housing of the injector is made from a thin-walled sheet-metal part. The sheet-metal part has at least two branches or legs. Each branch has, at the free end thereof, an angled retaining element or a recess as a means of receiving the cylinder of a cylinder/piston unit. The branches are elastic flexural beams which, in the middle area, are each bent in a Z-shape or S-shape to form a supporting portion for the piston-actuating ram. The contact zone situated between an individual supporting portion and the piston-actuating ram represents a wedge gear pairing that forces the respective branch outwards. The trigger unit comprises at least a trigger element which is slidably supported on the metal sheet, wherein the support section or, respectively the contact sections extend outwardly into longitudinal grooves. The branches may be provided with a locking tongue to engage corresponding openings in the trigger element to lock the housing in position as desired.

Claims

1. In combination with a disposable injector with a housing (200) in which or on which are arranged, in each case at least in some areas, at least one mechanical spring energy reservoir (50), at least one cylinder/piston unit (100) that can be filled at least temporarily with active substance, at least one piston-actuating ram (60) and at least one trigger unit (80),

the piston-actuating ram (60) is positioned between the spring energy reservoir (50) and the piston (111) of the cylinder/piston unit (100) including a cylinder (101),

the spring energy reservoir comprises at least one pretensioned spring element (50), and

the spring-loaded piston-actuating ram (60) is supported on the housing (200) in a releasable manner, the improvement which comprises:

the housing (200) is made from a thin-walled sheet-metal part (201),

the sheet-metal part (201) has at least two branches (220),

the branches (220) each have, at the free ends thereof, an angled retaining element (221) or a recess as a means of receiving the cylinder (101) of the cylinder/piston unit (100),

the branches (220) are elastic flexural beams which, in the middle area, are each bent in a Z-shape or S-shape to form a supporting portion (231) for the piston-actuating ram (60), each supporting portion (231) is adjoined by a bearing portion (232),

a contact zone situated between the individual supporting portion (231) and the piston-actuating ram (60) represents a wedge gear pairing that forces the respective branch (220) outwards, and

the trigger unit (80) comprises at least a trigger element (82) which is slidably supported on the metal sheet part (201), wherein the support portion (231) or, respectively the bearing portions (232) extend outwardly into rear longitudinal grooves (83)

at least one locking tongue (190) arranged on the at least two branches (220), the at least one trigger unit (82) having corresponding openings to received the at least one locking tongue (190) for locking the housing (200) in predetermined position.

2. Disposable injector according to claim 1, wherein the housing (200) is made from a sheet-metal strip (201), and the sheet-metal strip (201) is bent in a U-shape to form two branches (220).

3. Disposable injector according to claim 1, wherein the sheet-metal strip (201) has, at both free ends, inwardly angled retaining elements (221) as a bearing for the piston-actuating ram (60).

4. Disposable injector according to claim 1, wherein the branches (220) are at least five times longer than the width of the branches.

5. Disposable injector according to claim 1, wherein the supporting portion (231) encloses an angle of 115±

2 degrees with the portion (233) that carries the respective retaining element (221).

6. Disposable injector according to claim 1, wherein the supporting portion (231) encloses an angle of 113±

2 degrees with the portion (232) on which the spring element (50) laterally bears when the injector is tensioned.

7. Disposable injector according to claim 1, wherein the sheet-metal part (201) is made from a spring steel.

8. Disposable injector according to claim 1, wherein the trigger element (82) is a trigger tube surrounding the sheet-metal part (201).

9. Disposable injector according to claim 1, wherein the piston-actuating ram (60) is a flat plate (73) with a rectangular surface area or is made from a sheet-metal strip (73, 78) bent in a U-shape.

10. Disposable injector according to claim 1, wherein the trigger element (82), in combination with the housing (200) and with a tear-off banderole (90) secured thereon, forms a trigger unit (80).

11. Disposable injector according to claim 1, further comprising at least one locking tongue (190) arranged on the at least two branches (220), the at least one trigger unit (82) having corresponding openings to received the at least one locking tongue (190) for locking the housing (200) in predetermined position.

12. Disposable injector according to claim 11, wherein the at least one locking tongue (190) is formed by a U-shaped cut out gap (197) in the at least two branches (220).

13. Disposable injector according to claim 12, wherein the gap (197) ends in bores (198).

14. Disposable injector according to claim 11, wherein the least one locking tongue (190) is curved several times.

15. Disposable injector according to claim 11, wherein the at least one locking tongue (190) is composed of a resiliently outwardly deflecting portion (191) and a supporting portion (192).

16. Disposable injector according to claim 15, wherein the supporting portion (192) has a locking knob (193) proximate the centre thereof and a supporting end face (194).

17. Disposable injector according to claim 16, wherein the trigger element (82) has a locking bore (26) and a locking window (25) in predetermined position for engaging the supporting portion (192).

18. Disposable injector according to claim 1, wherein the at least two branches (220) each include a locking niche (234) and a wave-shaped guide bulge (235).

19. Disposable injector according to claim 18, wherein the at least one trigger element (82) further includes front longitudinal grooves (23) and a web (81) positioned between the rear longitudinal grooves (83) and the front longitudinal grooves (23), the locking niche (234) for engaging the web (81) upon triggering of the injector.

20. Disposable injector according to claim 19, wherein the retaining elements (221) in operative engagement with the cylinder (101), the wave-shaped guide bulge (235) positioned in close proximity to the retaining elements (221) for supporting the branches (220).