# US 2021/0330890 A1 · Injection Device

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- Number: US 2021/0330890 A1
- Document ID: US20210330890A1
- Status: Published application
- Kind: A1
- Application number: 17/273,875
- Filed: 2019-09-02
- Published: 2021-10-28
- Earliest claimed: 2018-09-08
- Assignees: Shaily Engineering Plastics Ltd.
- Applicants: Shaily Engineering Plastics Ltd.
- Inventors: Claus Schmidt Moeller
- Web page: https://patentgrep.com/patent/US20210330890A1

## CPC

- A61M 5/31551: {including axial movement of dose setting member}
- A61M 5/31501: {Means for blocking or restricting the movement of the rod or piston (A61M5/5013 takes precedence)}
- A61M 5/31563: {interacting with a displaceable stop member}
- A61M 5/31585: {the component being manually operated or triggered by an axially moving actuator operated by user, e.g. an axially movable injection button}
- A61M 5/31541: {Means preventing setting of a dose beyond the amount remaining in the cartridge}
- A61M 5/31558: {using scaling up or down transmissions, e.g. gearbox}
- A61M 5/31595: {Pre-defined multi-dose administration by repeated overcoming of means blocking the free advancing movement of piston rod, e.g. by tearing or de-blocking}
- A61M 2005/2403: {Ampoule inserted into the ampoule holder}
- A61M 2005/3126: {related to dosing}
- A61M 2205/581: by audible feedback
- A61M 2205/585: having magnification means, e.g. magnifying glasses
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

An injection device is disclosed wherein a dose can be set by rotating a dose setting member, whereby a push button is elevated from one end of the device a distance proportional to the set dose from a position fixed relative to the housing, and wherein the set dose can then be injected by pressing the push button back to its non-elevated position, through which motion a screw will move approximately the same distance or a smaller distance. The invention provides a method of reducing the dose force and/or the push-button movement during injection.

## Claims

### Claim 1

An injection device comprising:
a housing having a first thread,
a screw having a second thread and a non-circular cross section, and
a driver having a third thread and a fourth thread,
wherein:
the screw rotates during injection,
the third thread of the driver engages the first thread of the housing and the fourth thread of the driver engages the second thread of the screw,
the third thread and the fourth thread of the driver have the same leads and are headed in the same direction,
during dose setting the driver rotates and moves axially while the screw does not rotate or move axially, and
during injection the driver rotates together with the screw.

### Claim 2 (depends on 1)

An injection device according to claim 1, wherein:
an enlarging dose dial is engaged with a fifth thread in the housing having a higher lead than the threads on the driver, and
the driver is engaged with the enlarging dose dial via a track allowing axial movement between the driver and the dose dial.

### Claim 3 (depends on 1)

An injection device according to claim 1, wherein:
during injection the screw and the driver are rotationally coupled by means of a connecting tube, which is engaged with the non-circular cross section of the screw, and
the connecting tube during injection is rotationally coupled to the driver.

### Claim 4 (depends on 1)

An injection device according to claim 1, wherein:
the driver is coupled to a dose selector during dose setting and decoupled during injection, and
the driver and the dose selector move the same distance during dose setting and injection.

### Claim 5 (depends on 3)

An injection device according to claim 3, wherein:
a bi-directional ratchet is provided between the dose dial and the connecting tube, and
the bi-directional ratchet during dose setting indexes the dose dial on specific rotational positions around a revolution.

### Claim 6 (depends on 1)

An injection device according to claim 1, wherein:
a uni-directional ratchet is rotationally coupled to the screw and axially movable relative to the screw but not relative to the housing, and
the ratchet prevents the screw from moving back into the device towards the push-button end during dose setting and dose resetting.