Advancement mechanism for cartridge-based devices

A lancing device for using lancets in a rotary cartridge, the rotary cartridge defining a cartridge gear, the lancing device comprising:

• a housing;
• an operating handle that translates between retracted and extended positions and includes a grip, an elongate member extending from the grip and into the housing, and a rack gear defined by the elongate member, wherein the operating handle translates along a linear path between the first and second positions such that the first handle position is in a retracted position with the grip translated in and generally adjacent the housing, and wherein the second handle position is in an extended position with the grip translated away from the housing;
• and
• an advancement mechanism operable to sequentially advance the lancets for use, the advancement mechanism including a rotary drive gear assembly, an inter-gear unidirectional rotary ratcheting drive assembly, a second-gear unidirectional rotary ratcheting lock assembly, and a pinion output gear, wherein the rotary drive gear assembly includes a first rotary gear and a second rotary gear that rotate about a common axis, the first gear is rotationally driven by the operating handle rack gear in a first angular direction and an opposite second angular direction when the operating handle is translated between the retracted and extended positions, the second gear directly or indirectly rotationally drives the pinion output gear, and the pinion output gear rotationally drives the cartridge gear,
• wherein the inter-gear unidirectional rotary ratcheting drive assembly operably interconnects the first and second drive gears so that the second gear is driven by and rotates with the first gear in the first direction but is not driven in co-rotation by the first gear in the opposite second direction, wherein the inter-gear unidirectional rotary ratcheting drive assembly includes at least one inter-gear pawl that extends from the second drive gears and that defines a catch surface, and at least one inter-gear tooth that extends from the first drive gears and that defines a catch surface, and at least one inter-gear ramped surface defined by the inter-gear tooth and positioned adjacent the respective catch surface, wherein the catch surfaces engage each other to maintain the first and second drive gears in co-rotation in the first angular direction, the inter-gear pawl catch surface is moved out of engagement with the inter-gear tooth catch surface when the first gear rotates in the opposite second direction, and the catch surface disengagement is caused by the inter-gear ramped surface moving the inter-gear pawl, and
• wherein the second-gear unidirectional rotary lock assembly operably interconnects the first and second drive gears so that the second gear is free to be driven by and co-rotate with the first gear in the first direction but is locked from co-rotation in the opposite second direction, wherein the second-gear unidirectional rotary ratcheting drive assembly includes at least one second-gear tooth that extends from the second drive gear and that defines a lock surface, at least one second-gear pawl that extends from the housing and that defines a lock surface, and at least one second-gear ramped surface defined by the second-gear pawl and positioned adjacent the respective lock surface, wherein the lock surfaces engage each other to lock the second gear from rotation in the second direction, the second-gear pawl lock surface moves out of engagement with the second-gear tooth lock surface when the second gear rotates in the first direction, and the lock surface disengagement is caused by the second-gear ramped surface moving the second-gear pawl.