Injection device having a gearing arrangement
First Claim
1. An injection device comprising:
- a housing,a dose setting member being operable to set a dose by rotating said dose setting member relatively to the housing, about a rotational axis,a piston rod adapted to cause a set dose to be injected from the injection device,an injection button adapted to perform an axial movement, and operable to cooperate with the piston rod in injecting the set dose in such a manner that when the injection button is operated the set dose is caused to be injected by the piston rod,a gearing arrangement comprising at least one gear wheel, the gearing arrangement providing a gearing ratio between an axial movement of the injection button and an axial movement of the piston rod,wherein the gearing arrangement, during setting of a dose, is prevented from rotating along with the dose setting member about the rotational axis, and moves along the rotational axis relatively to the piston rod as the dose setting member is rotatedwherein at least one of the gear wheel(s) has a rotational axis which is non-parallel to the rotational axis of the dose setting member, andduring injection of the set dose, the piston rod is caused to move along with the gearing arrangement thereby maintaining its position relatively to the gearing arrangement.
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Accused Products
Abstract
An injection device with a gearing arrangement providing a gearing ratio between axial movement of an injection button and axial movement of a piston rod. The injection device comprises a dose setting member being operable to set a dose by rotating the dose setting member relatively to a housing, about a rotational axis. During setting of a dose the gearing arrangement is prevented from rotating along with the dose setting member about the rotational axis. Thereby the space which it is necessary to accommodate to the gearing arrangement inside the housing is reduced. This provides the possibility of using this space for other purposes, such as additional electronic components, designing the injection device in a manner which is appropriate for other purposes, e.g. with a relatively flat cross section, or reducing the overall size of the injection device. According to one aspect of the invention, the gearing arrangement comprises at least one gear wheel having a rotational axis which is non-parallel to, e.g. substantially perpendicular to, the rotational axis of the dose setting member. According to another aspect of the invention, the gearing arrangement comprises a driving spindle being provided with a threaded portion having a first pitch, and the piston rod is provided with a threaded portion having a second pitch. The gearing is provided by the threaded portions.
341 Citations
8 Claims
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1. An injection device comprising:
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a housing, a dose setting member being operable to set a dose by rotating said dose setting member relatively to the housing, about a rotational axis, a piston rod adapted to cause a set dose to be injected from the injection device, an injection button adapted to perform an axial movement, and operable to cooperate with the piston rod in injecting the set dose in such a manner that when the injection button is operated the set dose is caused to be injected by the piston rod, a gearing arrangement comprising at least one gear wheel, the gearing arrangement providing a gearing ratio between an axial movement of the injection button and an axial movement of the piston rod, wherein the gearing arrangement, during setting of a dose, is prevented from rotating along with the dose setting member about the rotational axis, and moves along the rotational axis relatively to the piston rod as the dose setting member is rotated wherein at least one of the gear wheel(s) has a rotational axis which is non-parallel to the rotational axis of the dose setting member, and during injection of the set dose, the piston rod is caused to move along with the gearing arrangement thereby maintaining its position relatively to the gearing arrangement. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification