Dental syringe having a medication filled carpule and a retractable needle cannula
First Claim
1. A syringe including a hollow syringe cylinder having an open distal end and comprising:
- a fluid filled carpule;
a hollow carpule adapter having forward and rearward ends and a needle carrier located at the forward end of and movable through said adapter, said carpule adapter receiving at least some of said carpule therewithin and said needle carrier having means to engage said carpule at the forward end of said adapter, said syringe cylinder being sized so that said combination carpule and carpule adapter can be loaded therein;
a double ended needle cannula to be attached to the needle carrier of said carpule adapter such that one end of said cannula penetrates said carpule and the opposite end of said cannula projects through the open distal end of said syringe cylinder for injecting the fluid contents of said carpule; and
means for moving said carpule towards the rearward end of said carpule adapter for correspondingly relocating said needle carrier and retracting said cannula rearwardly within said carpule adapter so as to be surrounded and shielded to thereby avoid an accidental needle stick.
1 Assignment
0 Petitions
Accused Products
Abstract
A reusable dental syringe including a conventional medication filled carpule and a conventional double ended needle cannula which is to be retracted into a compact enclosure to permit the safe handling and disposal of the cannula while avoiding an accidental needle stick and the possible spread of disease. The carpule is inserted into a hollow carpule adapter to engage a movable needle carrier at the distal end of the adapter. The combination carpule and adapter are loaded into the cylinder of the syringe, and the needle cannula is attached to the needle carrier to penetrate the carpule. At the conclusion of an injection, the combination carpule and carpule adapter are rotated outwardly from the syringe cylinder, and the carpule is then pulled rearwardly through the adapter, whereby to correspondingly relocate and anchor the movable needle carrier at the proximal end of the adapter. Accordingly, the needle cannula is retracted into and surrounded by the adapter so as to be irretrievably located and rendered non-reusable therewithin.
64 Citations
16 Claims
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1. A syringe including a hollow syringe cylinder having an open distal end and comprising:
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a fluid filled carpule; a hollow carpule adapter having forward and rearward ends and a needle carrier located at the forward end of and movable through said adapter, said carpule adapter receiving at least some of said carpule therewithin and said needle carrier having means to engage said carpule at the forward end of said adapter, said syringe cylinder being sized so that said combination carpule and carpule adapter can be loaded therein; a double ended needle cannula to be attached to the needle carrier of said carpule adapter such that one end of said cannula penetrates said carpule and the opposite end of said cannula projects through the open distal end of said syringe cylinder for injecting the fluid contents of said carpule; and means for moving said carpule towards the rearward end of said carpule adapter for correspondingly relocating said needle carrier and retracting said cannula rearwardly within said carpule adapter so as to be surrounded and shielded to thereby avoid an accidental needle stick. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A syringe including a hollow syringe body and a hollow syringe cylinder each of said body and said cylinder being axially aligned with one another and having open proximal and distal ends, said syringe comprising;
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a fluid filled carpule to be loaded into said cylinder, said carpule having a piston located at a proximal end thereof and movable through said carpule for expulsing the fluid contents thereof; a double ended needle cannula to be interconnected with said carpule so that one end of said cannula penetrates said carpule and the other end of said cannula projects outwardly through the distal end of said cylinder for injecting the fluid of said carpule; a piston stem movable axially through said syringe body to be connected to the piston of said carpule for controlling the movement of said piston through said carpule; a control rod advanceable distally through said syringe body and into said cylinder and having a retaining sleeve at one end thereof for surrounding and engaging the proximal end of said carpule to prevent the relocation of said carpule through said cylinder; catch means extending outwardly from and being movable with said control rod through said syringe body; and locking means associated with said syringe body for releasably engaging the catch means of said control rod a said control rod moves distally through said syringe body for locking said control rod at its distally advanced position and maintaining the retaining sleeve of said control rod in engagement with said carpule. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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16. A syringe including a hollow syringe body and a hollow syringe cylinder, each of said body and said cylinder being axially aligned with one another and having open proximal and distal ends, said syringe comprising:
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a fluid filled carpule having a piston movable therethrough for expulsing the fluid contents thereof; a double ended needle cannula to be interconnected with said carpule so that one end of said cannula penetrates said carpule and the other end of said cannula projects outwardly through the open distal end of said cylinder for injecting the fluid of said carpule; a piston stem movable axially through said syringe body and into said cylinder to be connected to the piston of said carpule for controlling the movement of said piston through said carpule; a hollow control rod for receiving said piston stem therethrough, said control rod advanceable distally through said syringe body and into said cylinder and having a retaining sleeve at one end for surrounding and engaging the proximal end of said carpule to prevent the relocation of said carpule through said cylinder; a flexible spring arm attached at one end thereof to said control rod and having a release button extending from the opposite end, said spring arm being movable with said control rod through said syringe body; a hole formed through said syringe body to removably receive the release button of said spring arm as said control rod moves distally through said syringe body for locking said control rod at its distally advanced position and maintaining the retaining sleeve of said control rod in engagement with said carpule; and compression spring means surrounding said control rod at the interior of said hollow syringe body, said spring means compressed against the normal spring bias when said control rod is moved to and locked at its distally advanced position, said compression spring means expanding when the release button of said spring arm is removed from the hole in said syringe body to release said control rod from its distally advanced position and drive said control rod proximally through said syringe cylinder and thereby retract said needle cannula into said cylinder through the open distal end thereof.
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Specification