US 5,222,945 AGranted

Hypodermic syringe with protective shield

OwnerRobert W. Basnightinventor

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Abstract

A safety syringe includes a barrel having an interior chamber for containing a fluid, and a needle mounted at one end of the barrel. The needle has a bore in fluid communication with the interior chamber in the barrel. A plunger is slidably mounted within the interior chamber of the barrel for displacing fluid within the barrel through the needle to administer fluid to a patient. A protective shield is slidably mounted on the barrel and is moveable between an extended position in which the needle is concealed and a retracted position in which the needle is exposed. The protective shield is moveable between first, second, and third positions. In the first position, the protective shield is extended over the needle and is releasibly locked to protect the needle prior to use. In the second position, the protective shield is retracted and is releasibly locked to facilitate use of the syringe. In the third position, the protective shield is again extended to cover the needle and is irreversibly locked to prevent reuse of the syringe. Reuse of the syringe is further prevented by a plunger locking mechanism which is engaged when the plunger is fully depressed.

Claims22

Dependent claims

A safety syringe comprising:

(a) a barrel having an interior chamber for containing a fluid and at least one longitudinally extending guide channel;
(b) a needle mounted to the barrel at one end of the barrel, said needle having a bore in fluid communication with the interior chamber in the barrel;
(c) a plunger slidably mounted within the interior chamber of the barrel for displacing the fluid within the barrel through the needle to administer fluid to a patient;
(d) a protective shield slidably mounted on the barrel and movable between an extended position in which the needle is concealed and a retracted position in which the needle is exposed;
(e) a key secured to the protective shield which fits into the guide channel of the barrel to guide the movement of the protective shield between the extended and retracted positions, said key including a plurality of serrations;
(f) means for releasably locking the protective shield in a first, extended position prior to the syringe being used;
(g) means for releasably locking the protective shield in a second retracted position to facilitate use of the syringe;
and
(h) means for irreversibly locking the protective shield in a third extended position after the syringe has been used to prevent reuse of the syringe, said irreversible locking means including a plurality of serrations formed on the barrel of the syringe which are engageable with the serrations on the key of the protective shield to irreversibly lock the protective shield in the third position.

6 more elements

A safety syringe comprising:

(a) a barrel comprising an interior chamber for containing a fluid;
(b) a needle mounted to the barrel at one end of the barrel, the needle having a bore in a fluid communication with the interior chamber in the barrel;
(c) a plunger slidably mounted within the interior chamber of the barrel for displacing the fluid within the barrel through the needle to administer fluid to a patient;
(d) a protective shield slidably mounted on the barrel and moveable between an extended position in which the needle is concealed, and a retracted position in which the needle is exposed;
(e) guide means for guiding the protective shield as it is moved between the extended and retracted positions relative to the barrel, the guide means including a longitudinally extending guide channel formed on one of the two parts, and a key having a plurality of serrations formed in the other of the two parts, wherein the key on one of the two parts is slidable in the guide channel in the other of the two parts;
(f) a first locking channel which intersects with the guide channel for receiving the key when the protective shield is placed in a first position wherein the first locking channel includes means for releasibly holding the key within the first locking channel;
(g) a second locking channel which intersects the guide channel for receiving the key when the protective shield is in a second locking position, wherein the second locking channel includes means for releasably holding the key within the second locking channel;
and
(h) a third locking channel which intersects with the guide channel for receiving the key when the protective shield is in a third position, the third locking channel including serrations for engaging the serrations on the key to irreversibly retain the key within the third locking channel, and to prevent reuse of the syringe.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/959,344Filed 13 Oct 1992
Granted: 29 Jun 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

A61M 5/3271
Being axially-extensible, e.g. protective sleeves coaxially slidable on the syringe barrel: with guiding tracks for controlled sliding of needle…
A61M 5/3272
With guiding tracks for controlled sliding of needle protective sleeve from needle exposing to needle covering position: having projections…
A61M 5/502
Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe: for blocking the piston
A61M 2005/31516
Piston or piston-rod constructions, e.g. connection of piston with piston-rod: reducing dead-space in the syringe barrel after delivery