Dispenser

Patent metadata

Field	Value
Publication number	US-10857563-B2
Application number	US-201716311151-A
Country	US
Kind code	B2
Filing date	Jun 30, 2017
Priority date	Jun 30, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A dispenser can prevent leakage of contents from a nozzle tip when stopping discharging the contents. A dispenser includes: a syringe body that has a filled space of contents, and has a discharge hole at a tip thereof; a plunger that is slid in the syringe body by application of a pushing force, to discharge the contents in the filled space from the discharge hole; and a piston that is formed of an elastic material and located at a tip part of the plunger, wherein a gap is formed between an inner peripheral surface of the syringe body and an outer peripheral surface of the piston, when the plunger is pushed, the piston deforms to narrow the gap, and a back leakage risk (=(gap area/final discharge hole area)) after the deformation of the piston is 0 or more and less than 1.

First claim

The invention claimed is:

1. A dispenser comprising:
a syringe body having a discharge hole at a tip thereof and a fillable space configured to contain contents;
a plunger configured to slide in the syringe body by application of a pushing force and to discharge the contents in the fillable space from the discharge hole; and
a piston that (i) is formed of an elastic material, (ii) is located at a tip part of the plunger, and (iii) includes: (a) a ring-shaped seal portion that forms a gap with an inner peripheral surface of the syringe body and (b) a tip wall that covers an inner peripheral surface of the seal portion from a tip side, wherein:
a thickness of the tip wall in a tip direction is smaller than a thickness of the ring-shaped seal portion in the tip direction,
the gap is formed between the inner peripheral surface of the syringe body and an outer peripheral surface of the piston,
when the plunger is pushed, the piston deforms to narrow the gap,
a tip of the plunger includes an inclined portion that decreases in diameter toward the discharge hole,
the ring-shaped seal portion is configured to move in a back end direction along the inclined portion and increase in diameter by a reaction force from the contents in the fillable space against the pushing of the plunger, and, when the pushing is stopped, move in the tip direction and decrease in diameter by an elastic force of the tip wall,
a back leakage risk after the deformation of the piston is 0 or more and less than 1, the back leakage risk being calculated by dividing an area of the gap by an area of a final discharge hole, and
a sliding portion that protrudes outward and that is configured to slide on the inner peripheral surface of the syringe body is provided intermittently in a circumferential direction of the dispenser at at least one of an outer peripheral surface of the plunger and the outer peripheral surface of the piston.

2. The dispenser according to claim 1 ,
wherein the discharge hole is formed by attaching a needle tip to the tip of the syringe body.

3. The dispenser according to claim 1 ,
wherein Shore hardness of the piston measured by a JIS K 6253 type A durometer is 30 or more and 80 or less.

4. The dispenser according to claim 1 ,
wherein an area ratio calculated by dividing a cross-sectional area of inside of the syringe body by the area of the final discharge hole is 20 or less.

5. The dispenser according to claim 1 ,
wherein a protrusion portion that prevents the plunger from separating from the syringe body is provided at the inner peripheral surface of the syringe body.

6. The dispenser according to claim 1 , wherein:
the piston includes: a back end portion that abuts the plunger and is prevented from being displaced in a back end direction; a sidewall that extends from the back end portion in the tip direction; and the tip wall that covers the sidewall from the tip side,
at least one of an inner peripheral surface and an outer peripheral surface of the sidewall is shaped to project outward, and the sidewall forms the gap with the inner peripheral surface of the syringe body, and
the tip wall is configured to move in the back end direction by the reaction force from the contents in the fillable space against the pushing of the plunger, and the sidewall is configured to be displaced outward with the movement of the tip wall.

7. The dispenser according to claim 2 ,
wherein Shore hardness of the piston measured by a JIS K 6253 type A durometer is 30 or more and 80 or less.

8. The dispenser according to claim 2 ,
wherein an area ratio calculated by dividing a cross-sectional area of inside of the syringe body by the area of the final discharge hole is 20 or less.

9. The dispenser according to claim 3 ,
wherein an area ratio calculated by dividing a cross-sectional area of inside of the syringe body by the area of the final discharge hole is 20 or less.

10. The dispenser according to claim 2 ,
wherein a protrusion portion that prevents the plunger from separating from the syringe body is provided at the inner peripheral surface of the syringe body.

11. The dispenser according to claim 3 ,
wherein a protrusion portion that prevents the plunger from separating from the syringe body is provided at the inner peripheral surface of the syringe body.

12. The dispenser according to claim 4 ,
wherein a protrusion portion that prevents the plunger from separating from the syringe body is provided at the inner peripheral surface of the syringe body.

13. The dispenser according to claim 1 , wherein, by virtue of the greater thickness of the ring-shaped seal portion relative to the tip wall, the inclined portion of the plunger contacts the ring-shaped seal portion so that the ring-shaped seal portion contacts the inner peripheral surface of the syringe body to seal the gap when the plunger is pushed.

Assignees

• Kuraray Noritake Dental Inc
• Yoshino Kogyosho Co Ltd

Inventors

• Horiguchi Hirotaka
• Yoshimura Kazuhisa
• Toma Toru

Classifications

• B05C17/00576 Primary

  characterised by the construction of a piston as pressure exerting means, or of the co-operating container · CPC title

• B05C17/01

  with {manually} mechanically or electrically actuated piston or the like {(B05C17/00533 takes precedence)} · CPC title

• B05C5/00

  Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work (B05C7/00 takes precedence; essentially involving spraying or electrostatic projection B05B) · CPC title

• B05C17/014

  comprising means for preventing oozing (B05C17/0146 takes precedence) · CPC title

• B05C5/02 Primary

  {the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g.} from an outlet device in contact or almost in contact, with the work · CPC title