Hollow needle applicators

• US 7,297,135 B2
• Filed: 12/12/2003
• Issued: 11/20/2007
• Est. Priority Date: 12/17/2002
• Status: Expired due to Fees

• Current Assignee: Safe-T Limited
• Original Assignee: Safe-T Limited
• Inventors: Jeffrey, Peter
• Primary Examiner(s): MEHTA, BHISMA
• Application Number:
  US10/536,992
• Publication Number:
  US 20050288633A1
• Time in Patent Office: 1,439 Days
• Field of Search: 604/110, 604/130, 604/131, 604133-136, 604/138, 604/139, 604/156, 604/157, 604/197, 604/198, 604/218, 604/232
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/3107 for needles
• 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 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user

Abstract

A fluid filled cartridge having a fixed needle and a piston assembly for expression of its contents is mounted inside an applicator. In order to extend the needle from the body prior to cartridge contents expression and without premature leakage of fluid therefrom, an actuator is mounted in the body to drive the cartridge forwards. This is accomplished by co-operating driving and driven parts of the actuator and the cartridge (or any carrier it may have) which are decoupled by release formations in the applicator body after the cartridge has been moved sufficiently to extend the needle. The applicator also includes provision for automatic needle retraction after cartridge contents expression. A separate inventive feature is the deformability of the piston so that force transmission to the trigger means to initiate needle retraction only occurs upon full content expression when the piston has “bottomed out” within the cartridge.

Claims

1. A hollow needle applicator for administering a fluid from a cartridge which has a fixed needle, said applicator comprising

an applicator body in which the cartridge is mounted;

a piston assembly located within the cartridge and slidable therein to discharge the fluid contents of the cartridge via the needle;

a force applying actuator mounted into the body and having at least one force transmitting part which provides a coupling with the piston assembly effective to displace the piston assembly within the cartridge to discharge contents of the cartridge; and

a provision for automatic needle retraction after cartridge contents discharge comprising spring means arranged within a forward portion of the applicator body to act between the applicator and the cartridge to which the needle is fixed;

wherein the piston assembly comprises a deformable piston, a piston rod which transmits force to the piston from the actuator, and a triggering means which is movable by the piston, when deformed into the end of the cartridge, to release the coupling between the force transmitting part or parts of the actuator and the piston assembly and bring about needle retraction; and

wherein

the piston rod is hollow and has driven extension parts which co-operate with the force transmitting part or parts of the actuator and are deflectable away from each other upon release from said force transmitting part or parts and the triggering means comprises a rod which is slidable within the hollow piston rod to deflect said extension parts.

2. A hollow needle applicator for administering a fluid from a cartridge which has a fixed needle, said applicator comprising

an applicator body in which the cartridge is mounted;

a piston assembly located within the cartridge and slidable therein to discharge the fluid contents of the cartridge via the needle;

a force applying actuator mounted into the body and having at least one force transmitting part which provides a coupling with the piston assembly effective to displace the piston assembly within the cartridge to discharge contents of the cartridge; and

a provision for automatic needle retraction after cartridge contents discharge comprising spring means arranged within a forward portion of the applicator body to act between the applicator and the cartridge to which the needle is fixed;

wherein the piston assembly comprises a deformable piston, a piston rod which transmits force to the piston from the actuator, and a triggering means which is movable by the piston, when deformed into the end of the cartridge, to release the coupling between the force transmitting part or parts of the actuator and the piston assembly and bring about needle retraction; and

wherein

the piston rod has driven extension parts which co-operate with the force transmitting part or parts of the actuator and are deflectable towards each other upon release from said force transmitting part or parts and the triggering means comprises a collar slidable about the piston rod to deflect said extension parts.

3. A hollow needle applicator for administering a fluid from a cartridge which has a fixed needle, said applicator comprising

an applicator body in which the cartridge is mounted;

a piston assembly located within the cartridge and slidable therein to discharge the fluid contents of the cartridge via the needle;

a force applying actuator mounted into the body and having at least one force transmitting part which provides a coupling with the piston assembly effective to displace the piston assembly within the cartridge to discharge contents of the cartridge; and

a provision for automatic needle retraction after cartridge contents discharge comprising spring means arranged within a forward portion of the applicator body to act between the applicator and the cartridge to which the needle is fixed;

wherein the piston assembly comprises a deformable piston, a piston rod which transmits force to the piston from the actuator, and a triggering means which is movable by the piston, when deformed into the end of the cartridge, to release the coupling between the force transmitting part or parts of the actuator and the piston assembly and bring about needle retraction; and

wherein

the piston rod has driven extension parts which co-operate with the force transmitting part or parts of the actuator and are coupled thereto by way of a drive coupling ring which is provided with spaced apertures and is rotatable by the triggering means to allow passage of the force transmitting and driven extension parts through these apertures.