Dose setting mechanism for an injection device capable of presetting a maximum dose

摘要

A dose setting mechanism for an injection device having a rotatably operated dose setting member, a presetting member being operable to limit the maximum dose settable by the dose setting member, and a first stopping member is operatively connected to the presetting member where the position of the first stopping member indicates the preset maximum dose. The first stopping member is adapted to rotatably engage with a second stopping member when the preset maximum dose has been set, thereby preventing setting of a further dose. The first and/or the second stopping member is/are movable along with the dose setting member, the first and second stopping members thereby being moved into engagement when a dose is set. Thereby a dose can be preset and the preset dose can easily be repeatedly set while ensuring an accurate dosage. Helps persons being visually impaired or having poor dexterity in setting a correct and accurate dose.

主权项

1. A dose setting device for setting the dose in an injection pen apparatus which has a housing, the dose setting device comprising:
a dose setting member that is rotatable by a user during a dose setting operation to set a dose, the dose setting member performing a spiral translation motion relative to the housing when rotated during dose setting and an opposite spiral translational motion during injection of the set dose such that the dose setting member returns to its original pre-dose setting position upon completion of ejecting of medication during the injection; a presetting member being operable to limit a maximum size of a set dose, the presetting member being rotatably and non-axially disposed on the housing between a distal and a proximal end of the housing, the presetting member being rotatable relative to the housing to set a maximum dose size, and the presetting member remaining rotatably disposed on the housing between the distal and proximal ends during presetting of the limit of the maximum dose size, which is accomplished by rotating the presetting member; a first stopping member coupled to the presetting member, wherein rotation of the presetting member results in a change in position of the first stopping member such that a user can preset a maximum dose size; a second stopping member that engages with the first stopping member and, when the first and second stopping members are engaged, the stopping members prevent rotation of the dose setting member in a direction that would allow the user to set a dose that is larger than the maximum preset dose which was set by the presetting member, and wherein a rotational force applied by and between the first and second stopping members as a result of their rotational abutment with each other during the setting of a dose via the dose setting member does not result in rotation of the presetting member and thus does not change the size of the maximum preset dose; wherein the first stopping member is moveable along with the dose setting member during the setting of a dose, the movement causing the first and second stopping members to perform a rotational movement relative to each other, the relative rotational movement causing the first and second stopping members to engage when the maximum settable dose has been reached during dose setting via the dose setting member, the maximum settable dose being one set by rotating the presetting member, wherein the first and second members engage rotationally and not axially during dose setting when the dose setting member is rotated and wherein during dose setting the angular distance between the first and second stopping members decreases until they engage.