Syringe-type ejector

Patent metadata

Field	Value
Publication number	US-10850040-B2
Application number	US-201615767865-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Oct 29, 2015
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

The syringe dispenser includes a syringe and a plunger. The plunger includes a first shaft member including a piston and second shaft member configured to be fitted in a tubular portion of the first shaft member. The first shaft member includes an elastic piece, the elastic piece being provided with a slide projection configured to slide on an inner surface of the syringe and a lock projection configured to be locked against the syringe. The second shaft member includes a pressing shaft configured to be fitted in the tubular portion. The pressing shaft is provided in a front end thereof with an end surface configured to press a free end of the elastic piece. In response to pressing from the end surface, the lock projection is locked against the rear end of the syringe, and in response to the pressing being released, the locking of the lock projection is released.

First claim

The invention claimed is:

1. A syringe dispenser comprising: a syringe; and a plunger configured to be pushed into the syringe, wherein
the plunger includes a first shaft member including a piston at a front end thereof; and a second shaft member configured to be fitted in a tubular portion of the first shaft member,
the first shaft member includes at least one elastic piece extending toward a rear side, the elastic piece being provided with a slide projection and a lock projection, the slide projection being configured to enter through a rear end opening portion of the syringe and slide on an inner circumferential surface of the syringe, and the lock projection being configured to be locked against a rear end of the syringe,
the second shaft member includes a pressing shaft configured to be fitted in the tubular portion, the pressing shaft being provided in a front end thereof with an end surface configured to press a free end of the elastic piece, and the pressing shaft being also provided on an outer circumferential surface thereof with an engagement projection configured to engage with an engagement portion of the tubular portion to prevent the second shaft member from slipping out,
in response to pressing from the end surface, the free end of the elastic piece is restrained between the second shaft member and the syringe, and the elastic piece undergoes a flexure deformation starting from the slide projection, and thus, the lock projection is locked against the rear end of the syringe,
in response to the pressing being released, the locking of the lock projection is released due to a restoring force from the flexure deformation that starts from the slide projection, and
the slide projection and the lock projection are coupled by a thinned portion having a thickness in a radial direction that is reduced.

2. The syringe dispenser of claim 1 , wherein the tubular portion is provided with an opening penetrating in a radial direction, and the elastic piece is arranged within the opening, with a rear end edge of the opening serving as the engagement portion.

3. The syringe dispenser of claim 1 , wherein a position of the end surface when the pressing is released is determined by the engagement projection abutting against the engagement portion of the tubular portion.

4. The syringe dispenser of claim 2 , wherein a position of the end surface when the pressing is released is determined by the engagement projection abutting against the engagement portion of the tubular portion.

5. The syringe dispenser of any one of claims 1 to 4 , wherein the elastic piece, in a portion from a base portion to the slide projection thereof, is formed to have a thickness in a radial direction that is gradually increased.

6. The syringe dispenser of any one of claims 1 to 4 , wherein the end surface is provided with a tapered surface.

7. The syringe dispenser of any one of claims 1 to 4 , wherein the first shaft member is provided on an outer circumferential surface thereof with a rib configured to engage with the rear end of the syringe in a position in which the pressing is started.

Assignees

• Kakuta Yoshiyuki
• Yoshino Kogyosho Co Ltd

Inventors

• Kakuta Yoshiyuki

Classifications

• A61M5/31595

  Pre-defined multi-dose administration by repeated overcoming of means blocking the free advancing movement of piston rod, e.g. by tearing or de-blocking · CPC title

• A61M5/315

  Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod {or piston}; Appliances on the rod for facilitating dosing {; Dosing mechanisms} · CPC title

• A61M5/31511

  Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence) · CPC title

• A61M5/3159

  Dose expelling manners · CPC title

• A61M5/5013

  Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe · CPC title