Nonreusable syringe with safety indicator
First Claim
1. A syringe having a retractable needle for injecting fluid into a body comprising:
- (a) a hollow tubular body member providing a cavity for the fluid, having an open end for insertion of a plunger;
(b) a plunger disposed partially within the tubular member having piston means in slidable sealed contact with the inner walls of the tubular member to define a chamber for the fluid at one end of the tubular member;
(c) a needle assembly within said tubular member having a needle in sealed contact with one end of the tubular member and extending therethrough to inject the fluid, the needle assembly including a rod having one end extending in sealed contact through said piston means and another end connected to said needle;
(d) resilient means disposed behind the piston means and connected to said one end of the rod, biased to retract the needle into the tubular member;
(e) lock means to lock the needle assembly in place with the needle extended from the tubular member;
(f) warning indicia on the plunger covered by an extension of the needle assembly when the plunger is inserted, the warning indicia being permanently uncovered when the plunger is withdrawn to fill the chamber with fluid to be injected; and
(g) release means to unlock the needle assembly and allow the resilient means to retract the needle after the plunger is fully depressed to inject the fluid in the chamber through the needle.
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Accused Products
Abstract
A nonreusable syringe is provided having an automatically retracting hypodermic needle to prevent accidental injury after injection or undesirable reuse of the syringe. The needle is retracted by a spring located behind the syringe piston and disposed to prevent reextension of the needle after use. A locking mechanism holds the needle in position for injection. The piston includes means to release the locking mechanism as injection is completed to automatically retract the needle into the syringe. The syringe tip seal is not in frictional contact with the needle, eliminating drag on the needle during retraction. A safety indicator is provided to indicate previous use.
70 Citations
26 Claims
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1. A syringe having a retractable needle for injecting fluid into a body comprising:
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(a) a hollow tubular body member providing a cavity for the fluid, having an open end for insertion of a plunger; (b) a plunger disposed partially within the tubular member having piston means in slidable sealed contact with the inner walls of the tubular member to define a chamber for the fluid at one end of the tubular member; (c) a needle assembly within said tubular member having a needle in sealed contact with one end of the tubular member and extending therethrough to inject the fluid, the needle assembly including a rod having one end extending in sealed contact through said piston means and another end connected to said needle; (d) resilient means disposed behind the piston means and connected to said one end of the rod, biased to retract the needle into the tubular member; (e) lock means to lock the needle assembly in place with the needle extended from the tubular member; (f) warning indicia on the plunger covered by an extension of the needle assembly when the plunger is inserted, the warning indicia being permanently uncovered when the plunger is withdrawn to fill the chamber with fluid to be injected; and (g) release means to unlock the needle assembly and allow the resilient means to retract the needle after the plunger is fully depressed to inject the fluid in the chamber through the needle. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A medical device having a retractable needle for injecting fluid into a body comprising:
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(a) a hollow tubular body having an upper open end and a lower end with tapered walls and a tubular axially-centered opening at the lower end having a seal therein; (b) a piston disposed within said tubular body in slidable fluid-sealed contact with the inner walls of the body, defining a fluid chamber below the piston; (c) a plunger attached to said piston for sliding the piston within the body, the plunger extending out the upper open end of the tubular body; (d) a needle assembly within said tubular body, having a needle in operative position extending through the opening in the lower end of the tubular body past the seal, and an elongated rod member having a lower end supporting the needle in fluid communication with said fluid chamber, the rod member extending upward through the piston in slidable sealed contact therewith and having an upper end portion extending substantially above the lower end of the tubular body; (e) a resilient member connected between the elongated rod member of the needle assembly and the tubular body and biased to exert a retraction force on the needle assembly with the needle extending in operative position from said opening in the lower end of said tubular body, (f) annular locking means located adjacent the tubular axially-centered opening of the tubular body for engaging a locking surface on the lower end of the elongated rod member, to hold the needle assembly in operative position with the needle extended; (g) a locking surface on the lower end of the rod member which cooperates with said annular locking means to engage and hold the needle assembly until released; and (h) said annular locking means and locking surface being released in response to force imposed by a release surface on the piston which comes into contact with the tapered walls at the lower end of the tubular body when the plunger is depressed to inject substantially all fluid from the chamber, whereupon the retraction force provided by the resilient member on the needle assembly immediately retracts the needle entirely within said body to prevent reuse of the device. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification