# US 2019/0314855 A1 · Syringe with piston assembly

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- Number: US 2019/0314855 A1
- Document ID: US20190314855A1
- Status: Published application
- Kind: A1
- Application number: 16/433,566
- Filed: 2019-06-06
- Published: 2019-10-17
- Earliest claimed: 2016-12-07
- Assignees: Henkel IP & Holding GmbH
- Applicants: Henkel IP & Holding GmbH
- Inventors: John P. Breault
- Web page: https://patentgrep.com/patent/US20190314855A1

## CPC

- B05C 17/00579: {comprising means for allowing entrapped air to escape to the atmosphere}
- G01F 11/027: {of the syringe type}
- B05C 17/00506: {Means for connecting the outlet element to, or for disconnecting it from, the hand tool or its container}
- B05C 17/00553: {with means allowing the stock of material to consist of at least two different components}
- B05C 17/00576: {characterised by the construction of a piston as pressure exerting means, or of the co-operating container}
- B05C 17/00593: {Hand tools of the syringe type}
- G01F 11/04: of the free-piston type
- G01F 15/02: Compensating or correcting for variations in pressure, density or temperature
- B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08)
- G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

## Abstract

A syringe assembly contains a fluid material, preferably two reactive fluid materials. The syringe assembly includes a syringe body having at least one barrel and a piston assembly movable within the barrel. An activatable plunger is in contact with the piston assembly effects dispensing movement of the piston assembly. The piston assembly includes an outer piston in sealed engagement with the barrel and an inner piston in sealed engagement with the outer piston. The inner piston is movable within the outer piston with and against the bias of a spring to maintain the inner piston in contact with the reactive material in the barrel upon thermal expansion and contraction of the reactive material.

## Claims

### Claim 1

A syringe assembly for containing and dispensing a fluid material comprising:
a syringe body having at least one barrel, said barrel having an open upper end and a lower end in communication with an outlet opening for accommodating and dispensing said fluid material;
a piston assembly movably positioned within said barrel, movable to dispense said material through said outlet opening; and
an activatable plunger in contact with said piston assembly to effect dispensing movement of said piston assembly;
said piston assembly including an outer piston in sealed engagement with said barrel and an inner piston in sealed engagement with said outer piston, said inner piston being movable within said outer piston with and against the bias of a spring to maintain said inner piston in contact with said fluid material in said barrel upon thermal expansion and contraction of said fluid material.

### Claim 2 (depends on 1)

A syringe assembly of claim 1 wherein said outer piston is generally a hollow cylinder having an outer cylindrical wall in sealed engagement with an inner wall of said barrel.

### Claim 3 (depends on 2)

A syringe assembly of claim 2 wherein said inner piston is a cylinder having an outer cylindrical wall in sealed engagement with an inner cylindrical wall of said outer piston.

### Claim 4 (depends on 3)

A syringe assembly of claim 3 wherein said spring is positioned between said outer piston and said inner piston; and wherein said inner piston is movable against the bias of said spring upon thermal expansion of said fluid material and returnable under the bias of said spring upon contraction of said fluid material.

### Claim 5 (depends on 1)

A syringe assembly of claim 1 wherein said syringe body includes at least two said barrels for dispensing at least two reactive materials including a piston assembly in each barrel, wherein at least one of said piston assemblies includes said outer piston and said inner piston.

### Claim 6 (depends on 5)

A syringe assembly of claim 5 further including a static mixer attachable to the exit opening of said barrels and in communication therewith for receiving and mixing said reactive materials.

### Claim 7 (depends on 6)

A syringe assembly of claim 6 wherein said static mixer include a dispensing tip for dispensing said mixed reactive materials.

### Claim 8 (depends on 5)

A syringe assembly of claim 5 wherein said outer piston is generally a hollow cylinder having an outer cylindrical wall in sealed engagement with an inner wall of said barrel.

### Claim 9 (depends on 8)

A syringe assembly of claim 8 wherein said inner piston is a cylinder having an outer cylindrical wall in sealed engagement with an inner cylindrical wall of said outer piston.

### Claim 10 (depends on 9)

A syringe assembly of claim 9 wherein said spring is positioned between said outer piston and said inner piston; and wherein said inner piston is movable against the bias of said spring upon said thermal expansion of said reactive material and returnable under the bias of said spring upon contraction of said reactive material.