US 5,106,379 AGranted

Syringe shielding assembly

OwnerE. Jack Leapinventor

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Abstract

A syringe having a sheath that is slidingly received on a barrel of the syringe so as to be movable between a retracted needle exposing position and an extended needle surrounding position. A boss fixedly attached to the syringe barrel cooperates with an L-shaped bayonet slot in the sheath to guide the cylindrical sheath. The sheath is connected to the syringe by a coil spring which biasingly urges the sheath into the extended needle surrounding position. The sheath is connected to the coil spring such that as the sheath is advanced from the retracted position to the extended position, the spring biasingly rotates the sheath with respect to the barrel such that the boss is advanced into a laterally extending portion of the slot so as to prevent accidental compression of the sheath. When the sheath is advanced to the retracted position a barb on the barrel cooperates with a barb receiving aperture in the sheath to restrain the sheath in the retracted position. A trigger on the sheath is engageable by a user to release the sheath from the retracted position.

Claims10

Dependent claims

A syringe comprising:

(a) a cylindrical syringe barrel having a interior chamber;
said barrel having a needle secured at a front end and a plunger slidingly received within the interior chamber;
(b) a boss extending radially outward from said cylindrical syringe barrel;
(c) a sheath slidingly positioned on said cylindrical syringe barrel and movable between a retracted needle exposing position and an extended needle surrounding position;
said sheath having a slot therein to receive said boss;
said slot including a longitudinal portion extending parallel to an axis of the syringe barrel and a laterally extending portion extending laterally with respect to said cylindrical syringe barrel and joined to said longitudinal portion;
(d) a spring biasingly urging said sheath towards the extended needle encircling position;
said spring being secured to said cylindrical syringe barrel and said sheath such that said spring biasingly rotates said boss into said laterally extending portion of said slot as said sheath is advanced to said extended needle surrounding position such that when said boss is positioned in said laterally extending portion of said slot said sheath may not be retracted due solely to axial forces acting on said sheath;
and
(e) restraining means for selectively restraining said sheath in said retracted needle exposing position;
(f) release means for selectively releasing said sheath from said restraining means so as to allow said spring to advance said sheath to said extended needle surrounding position.

8 more elements

A syringe comprising:

(a) a cylindrical syringe barrel having a needle secured at a front end and a plunger slidingly received therein;
(b) a boss fixedly attached to said cylindrical syringe barrel;
(c) a barb fixedly attached to said cylindrical syringe barrel;
(d) a sheath slidingly received about said cylindrical syringe barrel and movable between a retracted needle exposing position and an extended needle surrounding position;
said sheath having a slot therein to receive said boss;
said slot including a longitudinal portion extending axially along said barrel and a laterally extending portion extending laterally with respect to said barrel;
(e) a spring biasingly urging said sheath towards the extended needle surrounding position;
said spring being secured t said cylindrical syringe barrel and said sheath such that said spring also biasingly rotates said boss into said laterally extending portion of said slot as said sheath is advanced to said extended needle surrounding position such that when said boss is positioned in said laterally extending portion of said slot said sheath may not be retracted by only forces acting axially against said sheath but such that a user can manually rotate said sheath to allow retraction of said sheath;
(f) said sheath includes a barb receiving aperture positioned thereon such that when said sheath is advanced to the retracted needle exposing position said barb receiving aperture encircles said barb so as to prevent said sheath from being advanced to the extended needle surrounding position;
and
(g) said sheath further includes a trigger engageable by a user so as to advance said barb receiving aperture out of encircling relationship with said barb so as to allow said spring to biasingly urge said sheath to the extended needle surrounding position.

8 more elements

A syringe comprising:

(a) a cylindrical syringe barrel having a needle secured at a front end and a plunger slidingly received within the barrel;
said barrel including a pair of opposingly directed finger flanges extending outward from a rear end thereof;
(b) a boss fixedly attached to said barrel near said front end of said barrel;
(c) a barb fixedly attached to said barrel near said rear end of said barrel;
(d) a cylindrical sheath having a rear open end and a front open end and being slidingly received on said barrel and being movable between a retracted needle exposing position and an extended needle surrounding position;
said sheath having a slot therein to receive said boss;
said slot including a longitudinal portion extending axially along said barrel and a laterally extending portion extending laterally with respect to said barrel;
(e) a spring biasingly urging said sheath towards the extended needle surrounding position;
said spring being secured to said barrel and said sheath such that said spring also biasingly urges said boss into said laterally extending portion of said slot as said sheath is advanced to said extended needle surrounding position such that when said boss is positioned in said laterally extending portion of said slot, said sheath may not be retracted by only the application of an axial force to said sheath but a user may rotate said sheath against said spring to allow retraction of said sheath relative to said barrel;
(f) said sheath includes a barb receiving aperture positioned near said rear open end thereof such that when said sheath is advanced to the retracted needle exposing position said barb receiving aperture encircles said barb so as to prevent said sheath from being advanced to the extended needle surrounding position;
a pair of slits extend along said cylindrical sheath from said rear open end thereof on opposite sides of s id barb receiving aperture so as to form a tab;
and
(g) a trigger integrally connected to said tab such that said trigger is engageable by a user so as to swing said barb receiving aperture out of encircling relationship with said barb so as to allow said spring to biasingly urge said cylindrical sheath to the extended needle surrounding position.

10 more elements

Dependencies are inferred from the claim text.