Self disabling, single use, hypodermic syringe

• US 5,084,017 A
• Filed: 10/10/1989
• Issued: 01/28/1992
• Est. Priority Date: 10/10/1989
• Status: Expired due to Fees

• Current Assignee: John Maffetone
• Original Assignee: John Maffetone
• Inventors: Maffetone, John
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/419,499
• Time in Patent Office: 840 Days
• Field of Search: 604/110, 604/207-210, 604/218, 604/228, 604/229
• US Class Current: 604/110
• CPC Class Codes: 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
• CPC Class Codes: A61M 5/5013 Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe
• CPC Class Codes: A61M 5/5066 Means for preventing re-use by disconnection of piston and piston-rod

Abstract

A single-use, hypodermic syringe which disables itself during its initial application thereby preventing any subsequent use of the syringe. The working parts of the invention are designed to separate automatically when the syringe is oriented into the solution dispensing mode. These separated parts prevent subsequent aspiration of solutions into the syringe thereby rendering the syringe inoperable and unuseable after its initial use.

Claims

1. A single use, self disabling syringe comprising an elongate barrel tube incorporating an internal smooth bore, a small opening at the distal end of said barrel tube constrictedly configured for a hollow needle to be affixed to said distal end;

a plunger assembly axially disposed within said bore, said plunger assembly comprising a piston with incorporated seals of resilient material fitting snugly within said bore, an actuating rod connected to and extending from said piston and protruding through the proximal end of said barrel tube, said plunger assembly facilitates the initial aspiration and dispensing of a solution into and from said bore;

a means for irreversibly disconnecting said piston from said actuating rod whereby aspiration of a solution into said bore is not possible once originally aspirated solution is partially or fully dispensed, said disconnecting means comprising a spring arm detent and a locking lug on said distal end of said actuating rod; and

a lug engagement seat on said piston, radiused surface means for releasably interengaging said locking lug in said lug engagement seat, stop means for preventing reengagement of said lug in said seat, such that once disengaged, said lug cannot be reengaged in said seat.

2. The syringe of claim 1 further comprising a ratchet and pawl type detent for limiting forward movement of said plunger, wherein said detent includes a rod housing which functions in cooperation with said actuating rod, said rod housing being axially disposed within said proximal end of said bore such that said actuating rod moves reciprocatively within said rod housing.

3. The syringe of claim 1 wherein said syringe includes a safety shoulder cooperating between said actuating rod and said rod housing to block inadvertent or premature rotation of said actuating rod.

4. The syringe of claim 1 wherein said actuating rod is calibrated in combination with said rod housing such as to effect the aspiration and dispensing of whole or fractional volumetric quantities of a solution into and from said syringe.

5. The syringe of claim 2 wherein said detent, when in an engaged mode, prevents forward travel of said actuating rod and said piston within said bore.

6. The syringe of claim 2 wherein said detent, when in a disengaged mode, permits forward travel of said actuating rod and said piston within said bore.

7. The syringe of claim 1 wherein said actuating rod includes a plurality of guide tracks disposed along its axial length.

8. The syringe of claim 2 wherein said rod housing incorporates a guide pin, said guide pin, in cooperation with said guide tracks, effects straight line travel of said actuating rod in the rearward and forward directions within said bore.

9. The syringe of claim 2 wherein said actuating rod is disengaged from said rod housing when said actuating rod is rotated in a clockwise direction within said rod housing.

10. The syringe of claim 1 wherein said radiused surface means releasably disengages said locking lug from said seat once said actuating rod is rotated in the clockwise direction.

11. The syringe of claim 10 wherein said seals are in frictionally tight contact with said internal smooth bore of said barrel tube such that said seals prevent said piston from rotating about its longitudinal axis when said actuating rod is rotated within said piston.

12. The syringe of claim 10 wherein said disconnecting means has means creating an audible and a tactile click when said piston has been disconnected from said actuating rod by manual clockwise rotation of said actuating rod within said piston.

13. The syringe of claim 1 wherein said piston incorporates said stop means, said stop means comprising a return stop integral within said piston wall, said lug return stop preventing reconnection of said disconnected piston to said actuating rod.

14. The syringe of claim 2 wherein said actuating rod incorporates an integral travel stop, said travel stop limits rearward travel of said actuating rod within said barrel tube and prevents removal of said actuating rod from within said barrel tube.

15. The syringe of claim 1 wherein said plunger assembly is encapsulated within said barrel tube such that said piston is inaccessible once said syringe is fabricated at point of manufacture.