GEARBOX

• US 20130131595A1
• Filed: 02/16/2011
• Published: 05/23/2013
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Ekman, Matthew, Kemp, Thomas Mark, Barrow-Williams, Timothy Donald
• Granted Patent: US 9,358,351 B2
• Time in Patent Office: Days
• US Class Current: 604/117
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/208 Release is possible only when device is pushed against the skin, e.g. using a trigger which is blocked or inactive when the device is not pushed against the skin
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 2005/3247 Means to impede repositioning of protection sleeve from needle covering to needle uncovering position
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• 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 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: A61M 5/3257 Semi-automatic sleeve extension, i.e. in which triggering of the sleeve extension requires a deliberate action by the user, e.g. manual release of spring-biased extension means
• 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
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion
• CPC Class Codes: F16H 25/12 with reciprocation along the axis of rotation, e.g. gearings with helical grooves and automatic reversal or cams
• CPC Class Codes: Y10T 74/18656 Carriage surrounded, guided, and primarily supported by member other than screw [e.g., linear guide, etc.]

Abstract

The invention relates to a gearbox for converting a first translation into a second translation, the gearbox comprising a drive collar connectable to a translative drive means and prevented from rotating with respect to a ground of the drive means, a drive sleeve rotatably arranged at least partially inside the drive collar, engaged to the drive collar by a first screw thread and prevented from translating, wherein a plunger is arranged at least partially inside the drive sleeve, engaged to the drive sleeve by a second screw thread and prevented from rotating.

Claims

1. Gearbox for converting a first translation into a second translation, the gearbox comprising a drive collar connectable to a translative drive means and prevented from rotating with respect to a ground of the drive means, a drive sleeve rotatably arranged at least partially inside the drive collar, engaged to the drive collar by a first screw thread and prevented from translating, wherein a plunger is arranged at least partially inside the drive sleeve, engaged to the drive sleeve by a second screw thread and prevented from rotating, characterized in that the first screw thread and the second screw thread are like-handed.

2. Gearbox according to claim 1, characterized in that a pitch angle of the first screw thread and/or the second screw thread vary/varies over the length of the respective screw thread.

3. Gearbox according to claim 1, characterized in that the first screw thread and/or the second screw thread comprise at least one cam track in one of the engaged components and a ball or a follower for each cam track in the other one of the engaged components.

4. Auto-injector for administering a dose of a liquid medicament, the auto-injector having a distal end (P) and a proximal end (D) with an orifice intended to be applied against an injection site and comprising:

an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament (M), wherein the syringe is slidably arranged with respect to the housing,

a drive means capable of, upon activation;

pushing the needle from a retracted position into an advanced position through the orifice and past the proximal end (P), and

operating the syringe to supply the dose of medicament (M), and

activating means arranged to lock the drive means in a compressed state prior to manual operation and capable of, upon manual operation, releasing the drive means for injection,

characterized in that a gearbox according to one of the claims 1 to 3 is arranged between the drive means and the syringe or the stopper.

5. Auto-injector according to claim 4, characterized in that the drive means is arranged as a compression spring grounded at a distal end in a grounding member fixed to the housing, a proximal end of the drive means bearing against the drive collar.

6. Auto-injector according to claim 4, characterized in that an intermediary component is arranged for transmitting translation of the plunger to the syringe for advancing the syringe and the needle and wherein the intermediary component is arranged to be decoupled from the syringe and to couple the translation to the stopper when the needle reaches a defined injection depth.

7. Auto-injector according to claim 4, characterized in that a shroud is arranged at least partially inside the housing, the shroud (3) slidable in longitudinal direction between at least a retracted position, in which the needle is exposable and an advanced position, in which the needle is covered by the shroud, wherein the shroud is arranged to be locked in the retracted position prior to manual operation of the activation means and wherein the shroud is arranged to be pushed towards the advanced position by a syringe spring when the drive means has been released.

8. Auto-injector according to claim 7, characterized in that the shroud is slidable from the retracted position in distal direction (D) into an unlocking position by a small distance against the bias of at least one flexural element, wherein interlocking means are arranged to allow the activating means to be operated only, when the shroud is in the unlocking position, wherein the interlocking means are arranged to prevent the activating means from being operated otherwise.

9. Auto-injector according to claim 7, characterized in that a protective needle shield is attachable to the needle in a manner to partially protrude beyond the proximal end of the shroud through the orifice with the needle in its advanced position, wherein a syringe carrier is arranged inside the shroud for holding the syringe, the syringe carrier slidable with respect to the shroud, wherein the syringe carrier comprises at least one resilient snap for locking it to the shroud in order to prevent relative axial motion, wherein the snap is arranged to be supportable from inside by the protective needle shield when attached to the needle in order to remain engaged with the shroud and wherein the snap is inwardly biased to disengage from the shroud without support from inside in a manner to automatically disengage upon removal of the protective needle shield thus allowing the syringe and needle to be retracted into the retracted position under load of the syringe spring.

10. Auto-injector according to claim 7, characterized in that teeth are circumferentially arranged on an external surface of the drive sleeve, wherein a section of the shroud has internal splines for engaging with the teeth in order to prevent rotation of the drive sleeve when the shroud is in its advanced position, wherein another section of the shroud proximally adjacent to the splined section is arranged to allow rotation of the drive sleeve.

11. Auto-injector according to claim 7, characterized in that at least one resilient latch is arranged at the shroud for engaging in a respective recess of the housing when the shroud is translated into its advanced position.

12. Auto-injector according to claim 8, characterized in that at least one snap arm is distally arranged at the drive collar in a manner to be engageable behind a shoulder on the grounding member in order to prevent expansion of the drive means, the snap arm disengageable from the shoulder by being pushed outward by a respective resilient extension of a trigger button, the resilient extension arranged to be flexed outward by pushing the trigger button in proximal direction (P) thereby moving the resilient extension along a tapering surface of the grounding member, wherein the shroud is arranged to prevent at least one of the resilient extensions from flexing outwards when in the retracted position and wherein at least one distal recess is arranged in the shroud for allowing a respective resilient extension to be flexed outwards when the shroud is in its unlocking position.

13. Auto-injector according to claim 9, characterized in that the syringe spring bears against a shoulder in the shroud arranged between a distal portion and a proximal portion and against a rear flange of the syringe carrier.