# US 5,232,447 A · Non-reusable syringe

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- Number: US 5,232,447 A
- Document ID: US5232447A
- Status: Granted
- Kind: A
- Application number: 07/742,599
- Filed: 1991-08-08
- Granted: 1993-08-03
- Earliest claimed: 1991-08-08
- Assignees: JetFill, Inc.
- Inventors: Charles Schwarz; James D. Story
- Web page: https://patentgrep.com/patent/US5232447A

## CPC

- A61M 5/5013: {Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe}
- Y10S 128/919: Syringe, means to protect user
- 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)}
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A liquid dispensing syringe having a plunger unit that is non-retractable after liquid is dispensed. The syringe is only refillable by persons having special filling equipment.

## Claims

### Claim 1

A liquid dispensing syringe, comprising;
a cylindrically shaped hollow tube having one open end;
said tube having an inner wall defining a liquid chamber;
said tube having a conically shaped closure on the end located oppositely to said open end;
said closure defining a hollow tapered syringe needle mounting;
a plunger having a cylindrically shaped hollow body open at one end and conically closed on the end located oppositely to said open end;
said plunger having an outwardly projecting annular shoulder sealably engagable with said inner wall of said hollow tube when said plunger is slidably inserted into said open end of said tube;
said conically closed end cooperating with said conically shaped closure to force liquid through said needle mounting;
an actuator having a cylindrically shaped hollow body open at one end and closed on the end located oppositely said open end;
said actuators closed end having a generally radial top surface contoured to be engagable by the thumb of the user;
said actuator open end being slidably insertable into said open end of said plunger and abuttingly engagable with said plunger;
said actuator's closed end extending above said open end of said tube in a first position when said tube contains liquid;
said actuator's closed end being movable to a second position below said open end of said tube when applied axial pressure to said actuator forces said liquid from said tube; and
said actuator and plunger being returned to said first position by the positive pressure introduction of liquid through said needle mounting.