# US 10,441,720 B2 · Medical syringe

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,441,720 B2
- Document ID: US10441720B2
- Status: Granted
- Kind: B2
- Application number: 15/827,381
- Filed: 2017-11-30
- Published: 2018-06-28
- Granted: 2019-10-15
- Earliest claimed: 2016-12-28
- Assignees: Sumitomo Rubber Industries, Ltd.
- Applicants: Sumitomo Rubber Industries, Ltd.
- Inventors: Yuki Sakashita
- Web page: https://patentgrep.com/patent/US10441720B2

## CPC

- A61M 5/31513: {Piston constructions to improve sealing or sliding}
- A61M 2205/0222: Materials for reducing friction
- A61M 2205/0238: the material being a coating or protective layer
- A61M 2207/00: Methods of manufacture, assembly or production
- B29K 2027/18: PTFE, i.e. polytetrafluoroethylene {, e.g. ePTFE, i.e. expanded polytetrafluoroethylene}
- B29L 2031/7544: {Injection needles, syringes}
- 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)}
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

Medical syringe having a gasket excellent in sealability and slidability. The syringe includes a hollow cylindrical syringe barrel (11) and a gasket (13) fitted in syringe barrel (11). Gasket (13) includes a main body of an elastic material laminated with an inert resin film and has a circumferential surface portion (17) substantially maintained in contact with an inner surface (16) of syringe barrel (11). Gasket 13 also has an annular projection (22), provided on circumferential surface portion (17), extending circumferentially of circumferential surface portion (17). Projection (22) has a contact surface portion maintained in contact with inner surface (16) of syringe barrel (11) and having a width of 30 μm to 40 μm. Circumferential surface portion (17) has non-contact surface portions located out of contact with inner surface (16) of syringe barrel (11) on widthwise opposite sides of projection (22) and having a width of at least 30 μm.

## Claims

### Claim 1

A syringe comprising:
a hollow cylindrical syringe barrel; and
a gasket fitted in the syringe barrel;
wherein the gasket includes a main body made of an elastic material, and an inert resin film provided on a surface of the main body;
wherein the gasket has a circumferential surface portion which is made by the inert resin film substantially kept in contact with an inner surface of the syringe barrel, and an annular projection provided on the inert resin film on the circumferential surface portion as extending circumferentially of the circumferential surface portion;
wherein the projection has a contact surface portion kept in contact with the inner surface of the syringe barrel and having a width of not less than 30 μm and not greater than 40 μm;
wherein the circumferential surface portion has non-contact surface portions located out of contact with the inner surface of the syringe barrel on widthwise opposite sides of the projection and having a width of not less than 30 μm.

### Claim 2 (depends on 1)

The syringe according to claim 1, wherein the inert resin film comprises at least one of a polytetrafluoroethylene, an ethylene-tetrafluoroethylene copolymer and an ultrahigh-molecular-weight polyethylene, and a mixture of any of these polymers.

### Claim 3 (depends on 2)

The syringe according to claim 2, which is a prefilled syringe in which the syringe barrel is prefilled with a liquid drug.

### Claim 4 (depends on 1)

The syringe according to claim 1, which is a prefilled syringe in which the syringe barrel is prefilled with a liquid drug.