Automatic needle-retracting syringe
First Claim
1. An automatic needle retracting syringe for use with a liquid injectant comprising:
- a barrel having a needle end, a plunger end and defining a bore therein;
a plunger slidably mounted within the bore at the plunger end;
a needle gasket slidably mounted within the bore to divide said bore into a near region towards the plunger end and a far region towards the needle end, the needle gasket having a path formed therein communicating with the near region;
a hollow needle having a base and a point, the base mounted to the needle gasket in fluid communication with the path;
means for biasing the needle gasket and needle therewith towards a retracted position, the needle being housed entirely within the far region when the needle gasket is at the retracted position;
the needle gasket being movable between the retracted position and an extended position at which the tip of the needle extends from the needle end; and
means for maintaining the needle gasket in the extended position, said maintaining means including a dissolvable portion wedgeable between the tip of the needle gasket and the needle end of the barrel, the dissolvable portion configured to retain the tip of the needle gasket near the needle end of the barrel when the needle gasket is in the extended position, the dissolvable portion weakening upon contact with the liquid injectant over a period of time so as to release the needle gasket and permit the biasing means to move the needle gasket and needle therewith to the retracted position.
1 Assignment
0 Petitions
Accused Products
Abstract
An automatic needle-retracting syringe (2,80), intended for single use applications, includes a barrel (4), having a needle end (6), a plunger end (8) and a bore (10), and a plunger (12) at the plunger end. A needle gasket (16) is slidably mounted within the bore to define a near region (18) and a far region (20). A hollow needle (28) is mounted to the needle gasket. A path (26) through the needle gasket connects the near region to the needle. A coil spring (40,82) biases the needle gasket from an extended position to a retracted position, the needle fully housed within the barrel at the latter. The extended position is maintained by a retaining capsule (44) wedged between a narrowed bore portion (42) and the needle gasket. The retaining capsule is a gelatin which weakens upon contact with the liquid injectant so that after the liquid injectant contacts the retaining capsule for a period of time, the spring breaks the capsule causing the needle gasket to be moved back to the retracted position, thus retracting the needle back into the barrel. In addition, a supplemental flow path from the near region to the ambient environment can be created by dissolving a gelatin barrier to help prevent reuse of the syringe.
104 Citations
18 Claims
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1. An automatic needle retracting syringe for use with a liquid injectant comprising:
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a barrel having a needle end, a plunger end and defining a bore therein; a plunger slidably mounted within the bore at the plunger end; a needle gasket slidably mounted within the bore to divide said bore into a near region towards the plunger end and a far region towards the needle end, the needle gasket having a path formed therein communicating with the near region; a hollow needle having a base and a point, the base mounted to the needle gasket in fluid communication with the path; means for biasing the needle gasket and needle therewith towards a retracted position, the needle being housed entirely within the far region when the needle gasket is at the retracted position; the needle gasket being movable between the retracted position and an extended position at which the tip of the needle extends from the needle end; and means for maintaining the needle gasket in the extended position, said maintaining means including a dissolvable portion wedgeable between the tip of the needle gasket and the needle end of the barrel, the dissolvable portion configured to retain the tip of the needle gasket near the needle end of the barrel when the needle gasket is in the extended position, the dissolvable portion weakening upon contact with the liquid injectant over a period of time so as to release the needle gasket and permit the biasing means to move the needle gasket and needle therewith to the retracted position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A single use syringe for use with a liquid injectant comprising:
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a barrel having a needle end, a plunger end and defining a bore therein; a plunger slidably mounted within the bore at the plunger end, the plunger including a plunger gasket defining an injectant region between the plunger gasket and the needle end of the barrel; a hollow needle extending from the needle end of the barrel and having a point and a base, the base in fluid communication with the injectant region; a supplemental pathway fluidly coupling the injectant region and a supplemental region the supplemental region includes an axial bore within the plunger; and means for sealing the supplemental pathway until a period of time after the liquid injectant has been in contact with the sealing means, said sealing means being weakened by said contact with the liquid injectant so to permit flow of the liquid injectant from the injection region to the supplemental region after the period of time. - View Dependent Claims (16, 17)
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18. An automatic needle retracting syringe for use with a liquid injectant comprising:
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a barrel having a needle end, a plunger end and defining a bore therein; a plunger slidable mounted within the bore and extending out from the bore at the plunger end; a hollow needle having a base and a point and mounted to a needle gasket, the needle gasket slidably mounted within the bore to divide said bore into a near region towards the plunger end and a far region towards the needle end, the needle gasket having a main body, a tip extending towards the far region, a path fluidly coupling the point to the near region and a hole fluidly coupling the path to the far region; a spring disposed within the barrel between the needle gasket and the needle end, the spring biasing the needle gasket and needle therewith towards a retracted position wherein in the retracted position the needle is housed entirely within the barrel; the needle gasket being movable between the retracted position and an extended position at which the point of the needle extends from the needle end of the barrel; a dissolvable capsule secured in the barrel near the needle end and configured to receive and fictionally retain the tip of the needle gasket when the needle gasket is in the extended position, the dissolvable capsule constructed of material which dissolves upon contact with the liquid injectant over a period of time so as to compromise the frictional engagement between the tip and the capsule and thereby permit the spring to move the needle gasket and needle therewith to the retracted position; an axial bore within the plunger fluidly coupled to the near region; a dissolvable sealing means disposed within said axial bore which weakens during contact with the liquid injectant so to permit flow of the liquid injectant from the near region through axial bore and into a supplemental region.
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Specification