Force containment in an automatic injector
An automatic injector for delivering a pharmaceutical substance from a reservoir of a cartridge, the cartridge interconnected to a needle at its distal end and mechanically coupled to a plunger driver at its proximal end, the injector comprising a connecting feature on the cartridge a contact surface for contacting an injection site a frame connected to the contact surface, the frame having an interference element with a distal stop, the interference element sized to slidably link to the connecting feature and allow the cartridge to slide up to the distal stop, a snap element allowing the interference element to receive the connection feature, but inhibiting disconnection of the cartridge; the frame further comprising a driver mount, for fixedly containing a plunger driver, the driver for driving a plunger to empty the reservoir of the cartridge through the needle to inject fluid from the reservoir into the injection subject.
1. A receiving frame for immobilizing a cartridge to an automatic injector housing, the cartridge including a connection feature and a needle at a distal end of said cartridge, the cartridge being mechanically coupled at a proximal end of said cartridge to a plunger driver, the receiving frame comprising:
a ventral side configured to fit into a base portion of said automatic injector housing; and
a dorsal side including:
a cartridge mount configured to receive said cartridge from a first direction perpendicular to a longitudinal axis of the receiving frame, the cartridge mount configured to latch the cartridge in place after said cartridge is received from the first direction and slide in a second direction parallel to the longitudinal axis of the receiving frame, said cartridge mount comprising:
an interference element with a distal stop, wherein the interference element is sized to slidably link to said connection feature and allow said cartridge to slide in the second direction up to said distal stop; and
a snap element that allows the interference element to receive the connection feature, wherein the snap element is configured to inhibit disconnection of said cartridge from said interference element after the cartridge is received in the first direction, slid in the second direction, and latched in place; and
a driver mount configured to fixedly contain said plunger driver, said driver mount comprising a walled container sized to at least partially surround said plunger driver and defining an open top for receiving said plunger driver,
wherein said cartridge and said driver mount are configured to be mechanically coupled through said plunger driver.
2. The receiving frame of claim 1 , further comprising a motor mount, configured to fixedly contain a motor in operable communication with the plunger driver, said motor mount comprising a walled container sized to at least partially surround said motor and defining an open top for receiving said motor.
3. The receiving frame of claim 2 , wherein said cartridge mount, said driver mount, and said motor mount are a unitary piece.
4. The receiving frame of claim 2 , wherein a longitudinal axes of each of said cartridge, said plunger driver, and said motor are configured to be positioned on a same plane.
5. The receiving frame of claim 1 , wherein said driver mount contains forces of at least 20 kg-cm.
6. The receiving frame of claim 1 , wherein said interference element is shaped to surround a portion of said cartridge from a dorsal, a distal, and a ventral side of said portion of said cartridge.
7. The receiving frame of claim 1 , wherein the snap element is configured to elastically deflect during slidable engagement of the connection feature of the cartridge with the interference element of the cartridge mount and to subsequently release to snap back, immobilize and inhibit disconnection of the cartridge from the cartridge mount.
8. The receiving frame of claim 1 , wherein the interference element is sized to allow said cartridge to slide up to said distal stop along the second direction, and the distal stop and the snap element are together configured to inhibit movement of the connection feature of the cartridge along the second direction.
9. The receiving frame of claim 8 , wherein the snap element is configured to elastically deflect during sliding of the cartridge within the interference element in the second direction and to subsequently release to snap back and immobilize disconnection of the cartridge from the interference element.
10. The receiving frame of claim 1 , wherein the snap element is elastic.