HYPODERMIC SYRINGE

• US 3,677,246 A
• Filed: 02/17/1971
• Issued: 07/18/1972
• Est. Priority Date: 02/19/1970
• Status: Expired due to Term

• Current Assignee: Walter Stein
• Original Assignee: Walter Stein
• Inventors: Stein, Walter
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): McGowan, J. C.
• Application Number:
  US05/116,108
• Time in Patent Office: 517 Days
• Field of Search: 128/218G,218F,218D,218DA,218R,216,215,220,223,224,230,218M,213,235,173H
• US Class Current: 604/136
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling

Abstract

A hypodermic syringe which is provided with a relatively small injection chamber the volume of which is adjustable and from which an injection solution such as insulin or the like may be ejected by a piston through a hypodermic needle, and with a second relatively larger chamber, for example an ampoule, which is adapted to hold a relatively large supply of the injection solution and from which the injection chamber may be filled repeatedly for several injections.

Claims

1. A hypodermic syringe comprising a housing, a slidable injection cylinder disposed in said housing and provided with an injection chamber adapted to hold a relatively small, predetermined amount of an injection solution, a hypodermic needle carried by said cylinder and extending outwardly through said housing, a piston mounted for reciprocation in said injection chamber, a container adapted to hold a relatively large supply of an injection solution mounted for independent reciprocatory movement in said housing adjacent to said cylinder, valve controlled conduit means interconnecting said container and said injection chamber, pump means in said housing having an air inlet communicating with the exterior of said cOntainer and an outlet communicating with said container operable by reciprocatory movement of said container to force the injection solution from the container into said injection chamber, manually operable means for reciprocating said container to operate said pump, and spring actuated manually controlled means operable to slide said cylinder in said housing to insert said hypodermic needle in use and then to advance said piston in said injection chamber to eject said injection solution from said injection chamber through said hypodermic needle.

2. A hypodermic syringe as defined in claim 1 including means for varying the volume of said injection chamber and therefore the amount of injection solution ejected by said piston.

3. A hypodermic syringe as defined in claim 1 including adjusting means for varying the travel of said injection cylinder in said housing and consequently the insertion amount of said hypodermic needle.

4. A hypodermic syringe as defined in claim 2 wherein said volume varying means comprises a cap nut adjustably screwed on said injection cylinder, and means for maintaining said cap nut in a selected adjusted position.

5. A hypodermic syringe as defined in claim 1 wherein said pump means comprises two pump members telescopically slidable on each other, one of said members having said air inlet and said air outlet in the form of a hollow needle adapted to penetrate into said container.

6. A hypodermic syringe as defined in claim 5 including spring means for holding said pump members normally apart.

7. A hypodermic syringe as defined in claim 1 wherein said piston is operable by reciprocation of said container, and wherein said spring actuated means includes a main spring confined between said container and said housing adapted when released to effect a forward propulsion first of said injection cylinder, said container, and said piston simultaneously and subsequently forward movement of said piston in said injection cylinder to effect ejection of said solution from said injection chamber, means for loading said main spring and for holding it in loaded condition and means for releasing said main spring.

8. A hypodermic syringe as defined in claim 7 further including delaying means for insuring that said movement of said piston on said injection chamber will not occur until said injection cylinder has been moved a predetermined distance in said housing.

9. A hypodermic syringe as defined in claim 8 wherein said delaying means comprise a leaf spring secured to said injection cylinder guided in said housing and adapted to pivot away from the longitudinal direction of said cylinder through a slot in said housing and adapted initially to prevent relative movement between said container and said injection cylinder and then to permit such relative movement.

10. A hypodermic syringe as defined in claim 1, further including a cap nut adjustably mounted on said housing, and a transparent cap removably connected to said cap nut engageable by said injection cylinder to control the forward travel thereof in said housing.