# US 10,369,292 B2 · Syringe plunger assemblies

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- Number: US 10,369,292 B2
- Document ID: US10369292B2
- Status: Granted
- Kind: B2
- Application number: 15/405,078
- Filed: 2017-01-12
- Published: 2017-07-20
- Granted: 2019-08-06
- Earliest claimed: 2016-01-15
- Assignees: W. L. Gore & Associates, Inc.
- Applicants: W. L. Gore & Associates, Inc.
- Inventors: Erik M. LaRose
- Web page: https://patentgrep.com/patent/US10369292B2

## CPC

- A61M 5/31515: {Connection of piston with piston rod}
- A61L 31/048: {obtained by reactions only involving carbon-to-carbon unsaturated bonds (A61L31/041 takes precedence)}
- A61M 5/31505: {Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit}
- A61M 2005/31508: {provided on the piston-rod}
- A61M 2207/00: Methods of manufacture, assembly or production
- A61M 2209/04: Tools for specific apparatus
- 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)}
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)

## Abstract

A syringe for storing and delivering a fluid that includes (1) a stopper and (2) a plunger rod assembly is provided. The plunger rod assembly includes a plunger rod and a threaded member at a plunger-engaging end. The stopper may be formed of an elastomeric material. The stopper has an exterior surface and an inner cavity. The inner cavity of the stopper may have a generally frustoconical shape with at least one engagement surface. The threaded member contacts at least one engagement surface in the inner cavity of the stopper to support the plunger rod assembly in an integrated, non-threaded engagement with the stopper. In some embodiments, the threaded member is freely rotatable within the inner cavity.

## Claims

### Claim 1

A plunger assembly comprising:
a stopper comprising an elastomeric body, said stopper including:
an exterior surface; and
a non-threaded inner cavity, said inner cavity having a generally frustoconic shape and an engagement surface; and
a plunger rod having a threaded member at a plunger-engaging end,
wherein said stopper and said plunger rod are directly coupled together in an integrated, non-threaded engagement such that said plunger rod is freely rotatable and said threaded member is retained within said inner cavity when said stopper and said plunger rod are directly coupled together.

### Claim 2 (depends on 1)

The plunger assembly of claim 1, wherein said exterior surface comprises a plurality of outwardly extending ribs for engagement with a syringe barrel.

### Claim 3 (depends on 1)

The plunger assembly of claim 1, wherein said threaded member is rotatable within said inner cavity.

### Claim 4 (depends on 1)

The plunger assembly of claim 1, wherein a portion of said inner cavity comprises at least one non-engaging surface that does not contact said threaded member.

### Claim 5 (depends on 1)

The plunger assembly of claim 1, wherein said inner cavity comprises a plurality of engagement surfaces and non-engaging surfaces.

### Claim 6 (depends on 5)

The plunger assembly of claim 5, wherein each said engagement surface is spaced apart from one another.

### Claim 7 (depends on 1)

The plunger assembly of claim 1, wherein said threaded member contacts said engagement surface to support said plunger rod in an integrated, non-threaded engagement with said stopper.

### Claim 8 (depends on 1)

The plunger assembly of claim 1, wherein, said threaded member contacts said engagement surface to support the plunger rod in said integrated, non-threaded engagement.

### Claim 9

A syringe assembly comprising:
a cylindrical barrel having a smooth internal surface; and
a plunger assembly inserted into a receiving end of said cylindrical barrel, said plunger assembly comprising:
a stopper comprising an elastomeric body, said stopper including:
an exterior surface having plurality of outwardly extending ribs for engagement with said cylindrical barrel;
a non-threaded inner cavity, said inner cavity having at least one generally frustoconical portion and at least one engagement surface; and
a plunger rod having a threaded member at a plunger-engaging end,
wherein said threaded member contacts said engagement surface of said inner cavity to support said plunger rod in an integrated, non-threaded engagement with said stopper, and
wherein said plunger rod is freely rotatable and said threaded member is retained within said inner cavity when said stopper and said plunger rod are directly coupled together.

### Claim 10

A plunger assembly for a fluid dispensing syringe, the plunger assembly comprising:
a plunger rod having a distal end comprising a threaded member, the threaded member including a variable major diameter; and
a stopper comprising an elastomeric body including a distal end and a proximal end, the stopper defining a non-threaded inner cavity that includes first and second frustoconical inner surfaces connected to an opening, each said frustoconical inner surface being oriented to adjoin each other at a large termination end;
wherein at least one of the frustoconical inner surfaces is configured to engage the threaded member,
wherein said plunger rod is directly coupled to said stopper in an intergrated non-threaded engagement, and
wherein said plunger rod is freely rotatable and said threaded member is retained within said inner cavity when said stopper and said plunger rod are directly coupled together.

### Claim 11 (depends on 10)

The plunger assembly of claim 10, wherein the inner cavity is sized and shaped to receive the threaded member.

### Claim 12 (depends on 10)

The plunger assembly of claim 10, wherein the inner cavity comprises a shape that is generally complementary to the shape of the threaded member.

### Claim 13 (depends on 10)

The plunger assembly of claim 10, wherein the inner cavity has smooth inner walls configured to engage the threaded member.

### Claim 14 (depends on 10)

The plunger assembly of claim 10, wherein the first frustoconical inner surfaces are located proximal to the second frustoconical inner surfaces and are distal to the opening.

### Claim 15 (depends on 10)

The plunger assembly of claim 10, wherein each frustoconical inner surface comprises a small termination end, a large termination end, and a tapered surface extending between the small and large termination ends.

### Claim 16 (depends on 10)

The plunger assembly of claim 10, wherein the first and second frustoconical inner surfaces form an abutment having an inner diameter that is larger than a maximum diameter of the inner cavity.

### Claim 17 (depends on 10)

The plunger assembly of claim 10, wherein the first and second frustoconical inner surfaces together form a hexagonal shaped inner cavity within the plunger.

### Claim 18 (depends on 10)

The plunger assembly of claim 10, wherein the first and second frustoconical inner surfaces, provide an engagement region for engaging the threaded member.

### Claim 19 (depends on 10)

The plunger assembly of claim 10, wherein the first frustoconical surfaces of the plunger engage with the threaded member to retain the threaded member within the inner cavity of the plunger.

### Claim 20 (depends on 10)

The plunger assembly of claim 10, wherein threaded regions of the threaded member form a tapered profile that seats against the first and second frustoconical inner surfaces.

### Claim 21 (depends on 10)

The plunger assembly of claim 10, wherein the threaded member is retracted from a plunger with a force that is equal to or greater than a predetermined maximum retention force.