Display arrangement for an injection device

A display arrangement for an injection device for displaying a size of a dose of a medicament, the display arrangement comprising:

• a housing providing a rotation axis extending in an axial direction;
• a first display member rotatably supported inside the housing with regard to the rotation axis and comprising at least one cam radially offset from the rotation axis;
• a second display member rotatably supported inside the housing with regard to the rotation axis and arranged axially adjacent to the first display member;
• and
• a coupling member rotatably engaged with the second display member,
• wherein the at least one cam only selectively engages with the coupling member, wherein the coupling member is engaged with the at least one cam of the first display member only when the first display member is in a predefined angular position or angular range,
• wherein a retaining arrangement is configured to engage the coupling member with the first display member when the at least one cam of the first display member and the coupling member are disengaged,
• wherein the coupling member is rotatably supported in the housing with regard to a coupling axis extending parallel and radially offset to the rotation axis, and
• wherein the coupling member comprises a first geared section with a plurality of first teeth to mesh with the at least one cam when the first display member is in the predefined angular position or angular range.

A drive mechanism for an injection device for dispensing a dose of a medicament, the drive mechanism comprising:

• an elongated housing extending in an axial direction and providing a rotation axis extending in the axial direction;
• a piston rod configured to operably engage with a piston of a cartridge and further configured to displace the piston in an axial distal direction;
• a dose setting member rotatably supported on the housing;
• a drive sleeve rotatably or threadedly engaged with the piston rod;
• and
• a display arrangement comprising:
• a first display member rotatably supported inside the housing with regard to the rotation axis and comprising at least one cam radially offset from the rotation axis;
• a second display member rotatably supported inside the housing with regard to the rotation axis and arranged axially adjacent to the first display member;
• and
• a coupling member rotatably engaged with the second display member,
• wherein the at least one cam selectively engages with the coupling member, wherein the coupling member is engaged with the at least one cam of the first display member only when the first display member is in a predefined angular position or angular range,
• wherein a retaining arrangement is configured to engage the coupling member with the first display member when the at least one cam of the first display member and the coupling member are disengaged,
• wherein the display arrangement is alternately engageable with the drive sleeve and with the dose setting member for dispensing or setting of the dose of the medicament, and
• wherein the retaining arrangement comprises at least two retaining teeth separated in a circumferential direction on an outer circumference of the coupling member, wherein the at least two retaining teeth are in radial abutment with a retaining ring of the first display member when the first display member is outside the predefined angular position or angular range.

An injection device for dispensing a dose of a medicament, comprising:

• an elongated housing extending in an axial direction and providing a rotation axis extending in the axial direction;
• a piston rod configured to operably engage with a piston of a cartridge and further configured to displace the piston in an axial distal direction;
• a dose setting member rotatably supported on the housing;
• a drive sleeve rotatably or threadedly engaged with the piston rod;
• a display arrangement comprising:
• a first display member rotatably supported inside the housing with regard to the rotation axis and comprising at least one cam radially offset from the rotation axis;
• a second display member rotatably supported inside the housing with regard to the rotation axis and arranged axially adjacent to the first display member;
• and
• a coupling member rotatably engaged with the second display member,
• wherein the at least one cam selectively engages with the coupling member, wherein the coupling member is engaged with the at least one cam of the first display member only when the first display member is in a predefined angular position or angular range,
• wherein a retaining arrangement is configured to engage the coupling member with the first display member when the at least one cam of the first display member and the coupling member are disengaged,
• wherein the display arrangement is alternately engageable with the drive sleeve and with the dose setting member for dispensing or setting of the dose of the medicament, and
• wherein the retaining arrangement comprises at least two retaining teeth separated in a circumferential direction on an outer circumference of the coupling member, wherein the at least two retaining teeth are in radial abutment with a retaining ring of the first display member when the first display member is outside the predefined angular position or angular range;
• and
• a cartridge at least partially filled with the medicament and being arranged to operably engage the piston rod.