# US 12,766,266 B2 · Dosage adjuster for syringe

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- Number: US 12,766,266 B2
- Document ID: US12766266B2
- Status: Granted
- Kind: B2
- Application number: 17/785,876
- Filed: 2020-12-24
- Published: 2023-01-19
- Granted: 2026-10-20
- Earliest claimed: 2019-12-25
- Assignees: Taisei Kako Co., Ltd.
- Applicants: Taisei Kako Co., Ltd.
- Inventors: Tsuyoshi Somekawa; Miku Hori
- Web page: https://patentgrep.com/patent/US12766266B2

## CPC

- A61M 5/31548: {Mechanically operated dose setting member}
- A61M 5/31553: {without axial movement of dose setting member}
- A61M 5/31593: {Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir}
- A61M 5/31528: {by means of rotational movements, e.g. screw-thread mechanisms}
- 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

Provided is a dosage adjuster for a syringe including: a dosage setting part configured to set the amount of dosage usable out of a liquid medicine filled in the syringe; and a setting restriction part configured to switch between a restricted state in which change in setting of the amount of dosage set by the dosage setting part is restricted and a permissible state in which the change in the setting of the amount of dosage by the dosage setting part is permissible.

## Claims

### Claim 1

A dosage adjuster for a syringe comprising:
a dosage setting part configured to set an amount of dosage dischargeable out of a liquid medicine filled in the syringe; and
a setting restriction part configured to switch between a restricted state in which change in setting of the amount of dosage set by the dosage setting part is restricted and a permissible state in which the change in the setting of the amount of dosage by the dosage setting part is permissible, wherein
the dosage setting part comprises a setting operation part configured to rotate in a circumferential direction around a central axis of a plunger of the syringe to thereby initiate change in the setting of the amount of dosage,
the setting restriction part comprises a restriction operation part configured to move in a moving direction in which the plunger moves forward and rearward to thereby switch between the restricted state and the permissible state, and an anti-rotation part having a cylindrical shape and fixed to the cylinder in a state where the rotation in the circumferential direction is restricted,
the restriction operation part is integrated with the setting operation part, and is configured to be inserted into the anti-rotation part,
interfering projections are formed on an outer surface of the outer surface of the restriction operation part,
anti-rotation projections are formed on an inner surface of the anti-rotation part,
the restriction operation part is configured to restrict rotation of the setting restriction part by the movement toward one side in the moving direction to cause the interfering projections and the anti-rotation projections to be engaged with each other, and permit the rotation of the setting restriction part by the movement toward another side in the moving direction to cause the interfering projections and the anti-rotation projections to be disengaged from each other.

### Claim 2 (depends on 1)

The dosage adjuster for the syringe according to claim 1, wherein
the moving direction toward the one side of the restriction operation part coincides with the rearward direction in which the plunger is moved rearward, and the moving direction toward the other side of the restriction operation part coincides with the forward direction in which the plunger is moved forward, and
the restriction operation part comprises a stopper flange that extends radially outward and orthogonal to the central axis of the plunger.

### Claim 3 (depends on 2)

The dosage adjuster for the syringe according to claim 2, further comprising:
an operation cylinder that has a cylindrical shape and is configured to, in a state where the syringe is inserted through the operation cylinder, be rotatable in the circumferential direction around the plunger and slidable in the moving direction in which the plunger is moved forward and rearward, wherein
the operation cylinder comprises the dosage setting part and the setting restriction part.

### Claim 4 (depends on 1)

The dosage adjuster for the syringe according to claim 1, wherein
the dosage setting part comprises a movable receiving part that is arranged on an opposite side of a front surface of a flange of the plunger of the syringe and is movable forward in the moving direction of the plunger from a position in contact with the front surface of the flange, and
the movable receiving part is configured to set the amount of dosage on the basis of a distance away from the flange in the forward direction.