Disposable safety syringe

• US 5,147,303 A
• Filed: 05/23/1991
• Issued: 09/15/1992
• Est. Priority Date: 05/23/1991
• Status: Expired due to Fees

• Current Assignee: Bret C. Martin
• Original Assignee: Bret C. Martin
• Inventors: Martin, Bret C.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US07/704,395
• Time in Patent Office: 481 Days
• Field of Search: 604/110, 604/198, 604/263, 604/192, 604/187
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/325 Means obstructing the needle passage at distal end of a needle protection sleeve
• CPC Class Codes: A61M 5/3257 Semi-automatic sleeve extension, i.e. in which triggering of the sleeve extension requires a deliberate action by the user, e.g. manual release of spring-biased extension means

Abstract

Disclosed is a conventional syringe held within a sheath against the bias of a compression spring by a latch engaging an upper end of the compression spring which is also attached to an upper flange of the cylinder of said syringe. The lower end of said spring is attached to a rubber gasket or o-ring which is also attached to said sheath. At the lower end of the sheath is an opening for a needle which may be sealed by a pivoted spring biased disc when the needle is withdrawn into the sheath. The gasket and disc may include spongy material to absorb any liquid which may leak from the needle after withdrawal into the sheath. When the needle is to be disposed of, the syringe is depressed far enough to cam the latch out of engagement with the upper end of said compression spring enabling said compression spring to raise said syringe relative to said sheath enough to withdraw said needle into said sheath, thereby sealing the needle without subjecting the user to accidental pricks.

Claims

1. A disposable safety syringe comprising:

a sheath means having an opening for slidably receiving a syringe means therein;

a syringe means slidably received in said sheath means;

needle means extending from said syringe means;

latch mean holding said syringe means in operative position within said sheath means;

means for sealing said needle means within said sheath means after said latch means is released prior to disposal of said safety syringe;

whereby handlers of said safety syringe are protected from accidental pricks by said needle means subsequent to use thereof;

said sheath means comprising a central elongated cylinder means having a longitudinal opening therethrough, an upper cup means having a base means integral with said central elongated cylinder means and having a longitudinal opening therein communicating with and having a larger diameter than the longitudinal opening of said central elongated cylinder means, and a lower cap means having a small diameter opening therein for said needle means;

said syringe means comprising an elongated cylinder means slidable in the longitudinal opening of said central elongated cylinder means of said sheath means at one end and a depressor plate means at the other end, said plunger means insertable in said elongated cylinder means of said syringe means, and a needle mount means at the base of said elongated cylinder means of said syringe means, said needle means being mounted in said needle mount means; and

said sealing means comprising a compression spring means surrounding said elongated cylinder means of said syringe means, one end of said compression spring means being attached to an upper flange means of said elongated cylinder means of said syringe means, a lower end of said compression spring means being attached to a gasket means surrounding said elongated cylinder means of said syringe means, said gasket means also being attached to said base means of said upper cup means of said sheath means, said latch means to engage and retain said compression spring means in a compressed state and thereby retaining said syringe means within said sheath means in an operational mode, said cap means having a spring biased pivoted disc means effective to cover and seal said small diameter opening therein when said needle means is withdrawn into said sheath means;

whereby when it is desired to dispose of said safety syringe a user depresses said depressor plate and said syringe means in said sheath means to an extent sufficient to release said latch means, thereby enabling said compression spring means to expand sufficiently to raise said syringe means in said sheath means and to withdraw said needle means into said sheath means, enabling said disc means to seal said small diameter opening, while said gasket means provides a seal above said needle means by cooperating with said elongated cylinder means of said syringe means, said user being protected against accidental needle pricks during disposal of said safety syringe.

2. A disposable safety syringe as in claim 1 said needle mount means and said needle means having mating threads thereon, whereby said needle means may be readily interchanged with another needle means.

3. A disposable safety syringe as in claim 1, said gasket means and said disc means including spongy material to absorb liquids which may leak from said needle means after sealing thereof.

4. A disposable safety syringe as in claim 1, wherein said latch means is attached to a sidewall of said upper cup means and is spring biased to engage said upper end of said compressions spring means.

5. A disposable safety syringe as in claim 1, wherein said latch means includes:

peg means extending from said flange means;

detent means including a U-shaped cavity for accepting internally said peg means and preventing said peg means from exiting said cavity in a direction of retraction of said cylinder means of said syringe means from said sheath means, and allowing said peg means to exit from said cavity in a direction of insertion of said cylinder means of said syringe means into said sheath means; and

spring torque biasing means for twisting said spring means when said peg means is inserted into said detent means;

whereby

when said cylinder means of said syringe means is inserted fully into said sheath means, said peg means exits said detent means and said cylinder means of said syringe means is twisted relative to said sheath means by said spring means, so that said cylinder means of said syringe means retracts from said sheath means to withdraw said needle means into said sheath means.