SYRINGE FOR INJECTION OF FRESHLY MIXED LIQUID-POWDER

• US 3,785,379 A
• Filed: 08/12/1971
• Issued: 01/15/1974
• Est. Priority Date: 08/12/1971
• Status: Expired due to Term

• Current Assignee: Milton J. Cohen
• Original Assignee: Milton J. Cohen
• Inventors: Cohen, Milton J.
• Primary Examiner(s): Laudenslager, Lucie H.
• Application Number:
  US05/171,207
• Time in Patent Office: 887 Days
• Field of Search: 128/218R,218M,218NV,216,220,224,234,272
• US Class Current: 604/88
• CPC Class Codes: A61M 2005/31598 having multiple telescopically sliding coaxial pistons encompassing volumes for components to be mixed
• CPC Class Codes: A61M 5/286 upon internal pressure increase, e.g. pierced or burst A61M5/283 takes precedence
• CPC Class Codes: A61M 5/288 by piercing without internal pressure increase A61M5/283 takes precedence
• CPC Class Codes: A61M 5/31596 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001

Abstract

A syringe formed of an inner tubular member adapted to contain a liquid carrier and an outer tubular member adapted to contain a dry medicament to be taken up with the carrier for injection whereby the materials are freshly mixed immediately prior to injection and wherein the dry medicament and liquid carrier are separably maintained in sealed relation one from the other until admixed immediately prior to injection, whereby the sealing means between said inner and outer tubular members comprises a sealing ring of flexible material within said inner tubular member in sliding engagement with the inner walls thereof and a needle assembly supported at the forward end of the inner tubular member, the forward end of the needle of the needle assembly terminating a short distance from the sealing ring prior to admixture and the needle piercing through said sealing ring when in position of admixture.

Claims

1. In a hypodermic syringe having a rigid inner tubular member having a forward end and a rearward end and a rigid outer tubular member having a forward end and a rearward end with the inner tubular member having an outer diameter less than the inner diameter of the outer tubular member to enable axial movement of the inner tubular member in telescoping relation within the outer tubular member, a piston ring member on the forward end of the inner tubular member dimensioned slidably to engage the inner walls of the outer tubular member in sealing relation, a hypodermic needle on the forward end of the outer tubular member, a piston plug slidable axially in the inner tubular member and means for actuating the piston plug for axial displacement within the inner tubular member, the improvement which comprises sealing means in the inner tubular member for sealing the portion of the inner tubular member beyond the sealing means from the outer tubular member and means for establishing communication through said sealing means between the outer portion of the inner tubular member and the outer tubular member, comprising a hollow penetrating needle pointed at one end and mounted in the forward end portion of the inner tubular member with the end of the hollow penetrating needle extending axially a short distance into the interior of the inner tubular member, and a piston plug extending continuously crosswise of the inner walls of the inner tubular member and having an outer sealing rib in sealing engagement with the inner walls of the inner tubular member and slidable axially within the inner tubular member between a normal position rearwardly of the hollow penetrating needle point and an operated position forwardly of the hollow penetrating needle point whereby the needle penetrates the sealing disc and communicates with the interior of the inner casing beyond the sealing disc, in which the rib portion of the piston plug is dimensioned to have a greater width than the central portion in endwise alignment with the hollow penetrating needle.

2. A hypodermic syringe as claimed in claim 1 which includes a rupturable closure sealing the forward end of the outer tubular member and a holder mounted on the forward end portion of the outer tubular member for supporting the hypodermic needle for movement between extended and retracted position, with the rearward end of the needle terminating a short distance forwardly of the rupturable closure when in extended position and penetrating through the rupturable closure when displaced to retracted position.

3. A hypodermic syringe as claimed in claim 1 which includes a flexible closure on the forward end of the inner tubular member with passages through the flexible closure in endwise alignment with the end portion of the inner tubular member for abutment to plug the passages when in normal sealed position and to free the passages responsive to pressure from within the inner tubular member to unseat the closure.

4. A hypodermic syringe as claimed in claim 1 in which the penetrating needle is mounted on the forward end of the inner tubular member.

5. A hypodermic syringe as claimed in claim 1 in which the inner tubular member is formed with a neck portion at the forward end and which includes a holder for the penetrating needle dimensioned to have a cross-section less than the cross-section of the inner tubular member but gReater than the neck portion whereby the holder for the penetrating needle rests upon the shoulder of the inner tubular member formed between the neck portion and the inner walls of said inner tubular member.

6. A hypodermic syringe as claimed in claim 1 in which the sealing disc is formed of an elastomeric material.

7. A hypodermic syringe as claimed in claim 1 in which the inner tubular member is adapted to contain a fluid and in which the outer tubular member is adapted to contain a dry material to be taken up by the fluid when the latter is caused to flow from the inner tubular member to the outer tubular member responsive to movement of the piston ring member axially within the inner tubular member.

8. A hypodermic syringe as claimed in claim 1 in which the sealing disc within the inner tubular member is formed of rubber-like material having annular axially spaced ribs dimensioned to extend into sealing engagement with the inner walls of the inner tubular member.

9. A hypodermic syringe as claimed in claim 1 in which the sealing disc comprises a pair of axially spaced rim portions, a tubular portion joining the inner areas of said rim portions and a thin disc portion spanning the tubular portion and rupturable by the penetrating needle.

10. A sealing means for sealing the interior of a tubular member from the outside comprising a hollow penetrating needle extending axially into the inner tubular member and a support fixed on the end of the inner tubular member for mounting the penetrating needle with the end portion of the needle extending a short distance axially into the inner tubular member, a sealing ring of flexible material within said inner tubular member dimensioned slidably to engage the inner walls of the tubular member in sealing relationship and mounted for axial movement between sealing position beyond the end of the penetrating needle and unsealing position forwardly of the end of the penetrating needle whereby the needle penetrates through the sealing disc for communication with the interior of the tubular member.

11. A sealing means as claimed in claim 10 in which the support for the hollow needle is fixed to the forward end of the tubular member.

12. A sealing means as claimed in claim 10 in which the tubular member is formed with a neck portion of smaller cross-section than the remainder to provide a shoulder portion therebetween and in which the support for the hollow needle is dimensioned to have a cross-section less than the cross-section of the tubular member but greater than the neck portion whereby the needle support rests on the shoulder in position of use.