Single dose disposable syringe with needle protector

This invention is a syringe having a tubular sleeve protector. The syringe has a barrel with an injection needle and a guide pin on an exterior surface of the barrel. The barrel and the injection needle are in an interior of a tubular sleeve has a spiral guide track on an interior wall. The guide pin fits in the spiral guide track and moves the barrel towards a bottom end of the tubular sleeve as the barrel is rotated, thereby extending the injection needle out of the tubular sleeve. A lateral guide track connects the spiral guide track to a vertical guide track. The guide pin moves from the bottom of the spiral guide track through the lateral guide track to the vertical guide track when the syringe barrel is further rotated. The injection needle is retracted into the interior of the tubular sleeve when the guide pin is moved into the vertical guide track and moved upwards in the vertical guide track towards a top end of the tubular sleeve.

FIELD OF THE INVENTION

This invention relates to tubular sleeves on syringes for covering and protecting injection needles prior to use wherein the barrel of the syringe can be pushed and pulled slideably in the tubular sleeve to advance the injection needle out of the tubular sleeve and to retract the injection needle back into the tubular sleeve, respectively. More particularly, this invention relates to a tubular sleeve constructed to advance and retract an injection needle on a syringe from the tubular sleeve by irreversible rotation in one direction of the syringe barrel within the tubular sleeve.

BACKGROUND OF THE INVENTION

Various forms of protective sleeves for hypodermic injection needles are known. See U.S. Pat. Nos. 4,170,993; 4,425,120; 4,693,708; 4,702,738; 4,723,943; and 4,966,592. All of these devices use linear tracks on an internal surface of a sheath or sleeve which fits slidably and rotatably around the barrel of a syringe and around an injection needle at the tip of the barrel. The barrel of the syringe is pushed or pulled linearly along the track relative to the sleeve or the sleeve is pushed or pulled linearly along the track relative to the barrel of the syringe to extend or withdraw the injection needle from the sleeve. The syringe barrel is rotatable relative to the sleeve so that the syringe barrel can be rotated to lock and unlock the syringe barrel at desired positions along the length of the sleeve. These devices have relatively complex structures and require relatively complex movements to extend the injection needle out of the sleeve and to withdraw the injection needle into the sleeve.

SUMMARY OF THE INVENTION

The present invention provides a single dose disposable syringe having a tubular sleeve protector. The syringe has a syringe barrel, a plunger, and an injection needle attached to the syringe barrel. A guide pin is attached to an exterior surface of the syringe barrel. The syringe barrel and the injection needle are positioned inside an interior of a tubular sleeve. The tubular sleeve has a spiral guide track on an interior wall of the tubular sleeve. The guide pin is constructed to fit in the spiral guide track and to move the syringe barrel towards a bottom end of the tubular sleeve as the syringe barrel is rotated, relative to the tubular sleeve, in the direction of the spiral guide track, from a top end of the spiral guide track to a bottom end of the spiral guide track. The injection needle is thereby extended out of the bottom end of the tubular sleeve. A lateral guide track on the interior wall of the tubular sleeve connects the spiral guide track to a vertical guide track on the interior wall of the tubular sleeve. The guide pin is constructed to move from the spiral guide track through the lateral guide track to the vertical guide track when the syringe barrel is further rotated in the direction of the spiral guide track. The injection needle is retracted into the interior of the tubular sleeve when the guide pin is moved into the vertical guide track and moved upwards in the vertical guide track towards a top end of the tubular sleeve.

A retaining slot is located at a first end (top end) and at a second opposite end (bottom end) of the spiral guide track and at a top end of the vertical track to retain the guide pin. A biasing member is located on the injection needle to bias the guide member upwards in the vertical guide track. The guide pin in the spiral guide track moves from the top end of the spiral guide track to the bottom end of the spiral guide track. The retaining slot at the bottom end of the spiral guide track is constructed to prevent a reverse in rotation of the syringe barrel.

A method of protecting a syringe needle on a single dose disposable syringe is also provided. The method includes extending the syringe needle out from a bottom end of the tubular sleeve by rotating the syringe barrel, relative to the tubular sleeve, in the direction of the spiral guide track and moving the guide pin from a top end of the spiral guide track to a bottom end of the spiral guide track. The method further includes retracting the injection needle back into the tubular sleeve by further rotating the syringe barrel, relative to the tubular sleeve, in the direction of the spiral guide track and by moving the guide pin across the lateral guide track and into the vertical guide track and moving the guide pin upwards in the vertical guide track towards the top end of the tubular sleeve, thereby moving the syringe barrel and syringe needle towards the top end of the tubular sleeve.

An advantage of the present invention is the ability to extend the injection needle from the protective tubular sleeve with a single rotation of the syringe barrel.

Another advantage is the ability to retract the injection needle back into the tubular housing with a single rotation of the syringe barrel.

Another advantage is a disposable syringe with a needle protector that is simple in construction, easy to use, and relatively inexpensive to manufacture.

DETAILED DESCRIPTION OF THE INVENTION

While the following description details the preferred embodiments of the present invention, it is to be understood that the invention is not limited in its application to the details of arrangement of the parts as shown in the figures or to the steps of the methods disclosed herein, since the invention is capable of other embodiments and of being practiced in various ways.

FIG. 1shows a perspective side view of an exemplary syringe10of the present invention, shown as a single dose disposable syringe. The syringe10has a barrel11with a top end12and a bottom end13. The bottom end13has an opening14into a nipple15extending from the bottom end13. An injection needle16is attached to the nipple15by methods well known in the art. The needle16has a biasing member, such as a spring21, attached thereto. A plunger17has a handle22and a tip18which is in the interior of the syringe barrel11. A prefilled dose of drug for injection19is shown in the interior of the syringe barrel11between the plunger tip18and the bottom13of the syringe barrel11. A guide pin20is shown attached to the exterior side of the syringe barrel11. The guide pin11is constructed for use with guide tracks on the internal wall of a tubular sleeve30as described below.

FIG. 2shows a side view of a tubular sleeve30of the present invention. The tubular sleeve30has a top end31, a bottom end32, and an interior33. The bottom end32is closed except for an opening34through which needle16can pass. The syringe barrel11does not pass through end32of the tubular sleeve30. Top end31of the tubular sleeve30is open. A spiral guide track35is shown on an interior wall36of the tubular sleeve30and is shown inFIG. 2from a first side37of the tubular sleeve as a solid line39and as a dashed line40on a second opposite side38. Spiral guide track35starts at its top end with a first retaining slot41and extends downward along solid line39on the first side37of the tubular sleeve30. Spiral guide track35then spirals around the interior wall36along dashed line40, on the second opposite side38, and has a second retaining slot42at its bottom end. The guide track then continues as a horizontal guide track, shown by dashed line43, along the interior wall36to a vertical guide track. The vertical guide track, shown by dashed line45, extends towards the top end31of the tubular sleeve30and terminates with a third retaining slot46at its top end.

FIG. 3shows an enlarged view of the spiral guide track35, the horizontal guide track43, and the vertical guide track45, shown from the first side37of the tubular sleeve30. The retaining slots41and42reversibly retain the guide pin20. Arrows47a,47b, and47cshow the direction of travel of the guide pin20along the guide tracks35,43, and45as the guide pin20travels along the guide tracks by rotation of the barrel11relative to the tubular sleeve30.FIG. 4shows an enlarged view of the spiral guide track35, the horizontal guide track43, and the vertical guide track45, shown from the second opposite side38of the tubular sleeve30. The guide tracks on the second opposite side38are shown in solid lines and the portion38of the guide track on the first side37is shown in a dashed line.

FIG. 5shows a view of the first side37of the syringe10inserted into the tubular sleeve30in a pre-use configuration. The injection needle16is enclosed within the tubular sleeve30. The guide pin20is positioned in the first retaining slot41. A prefilled dose of drug for injection19is shown between the plunger tip18and the bottom13of the barrel11. By rotating the syringe barrel11in the same direction as the spiral guide track35the guide pin20can be moved out of the first retaining slot41and advanced down the spiral guide track35, indicated by arrows47ashown inFIGS. 3 and 4.

FIG. 6shows that the guide pin20has been rotated into the second retaining slot42of the spiral guide track35. The rotation of the barrel11to the second position has caused the barrel11to move downward in the tubular sleeve30so that the needle16extends out of the tubular sleeve30through the opening34in the bottom end32of the tubular sleeve30. The downward movement of the barrel11has also caused the spring21to become compressed so that the syringe10is biased in an upward direction towards the top end31of the tubular sleeve30. The syringe10as shown inFIG. 6is in a for-use configuration and the drug dosage in the syringe10can be injected as prescribed by pushing the handle22of the plunger17to force the tip18of the plunger17to the bottom13of the barrel11, as is known in the art.

After injection of the drug dosage the barrel11can be rotated again, as illustrated inFIG. 7, to move the guide pin20laterally along the horizontal guide track43, shown by arrows47b(FIG. 3andFIG. 4) until it engages the vertical guide track45. When the guide pin20enters the vertical guide track45as a result of rotating the barrel11, the syringe10is free to move upward, shown by arrows47c(FIG. 3andFIG. 4) and the force of the compressed spring21will cause guide pin20to move upward until the guide pin20enters the third retaining slot46at the top of the vertical guide track45. The injection needle16is then retracted back into the tubular sleeve30. The syringe10is in an after-use configuration and is ready for disposal.

FIG. 8shows the syringe10having a finger grip50on the barrel11at the top end12to facilitate rotation of the barrel11. The finger grip50has, preferably, the same diameter as the tubular sleeve30. The finger grip50can be made of any suitable plastic or rubber or a combination thereof and have a ribbed or roughened surface to facilitate gripping and prevent slippage.

The second retaining slot is constructed, preferably, to seat the guide pin with a snap-like effect and with sufficient resistance for the guide pin to remain in the retaining slot, even with the spring compressed. However, the second retaining slot is also constructed so that the guide pin can be moved out of the second retaining slot with rotation of the barrel. The second retaining slot is further constructed, preferably, to prevent counter rotation of the barrel in an attempt to move the guide pin in an opposite direction along the spiral guide track. Once the guide pin enters the third retaining slot the guide pin, preferably, cannot be moved out of the third retaining slot.

The present invention provides a method of protecting a syringe needle on a single dose disposable syringe. A syringe having a syringe barrel, a plunger, and an injection needle is provided. Also provided is a guide pin on an exterior surface of the syringe barrel. The syringe barrel and injection needle are positioned inside a tubular sleeve so that the injection needle is protected. The tubular sleeve has a spiral guide track, a lateral guide track, and a vertical guide track on an interior wall of the tubular sleeve. The guide pin can fit into the spiral guide track, the lateral guide track, and the vertical guide track.

In order to use the syringe, the syringe needle must be extended out from a bottom end of the tubular sleeve. This is accomplished by rotating the syringe barrel, relative to the tubular sleeve, in the direction of the spiral guide track and by moving the guide pin from a top end of the spiral guide track to a bottom end of the spiral guide track, thereby moving the syringe barrel and injection needle towards the bottom end of the tubular sleeve. In this configuration, with the needle extended out of the tubular sleeve, the syringe is ready for use and a dosage in the syringe may be injected into a patient using the plunger.

In order to continue protecting the injection needle after use, the injection needle must be retracted back into the tubular sleeve. This is accomplished by further rotating the syringe barrel, relative to the tubular sleeve, in the direction of the spiral guide track and by moving the guide pin across the lateral guide track and into the vertical guide track. Once the guide pin is in the vertical guide track it is moved upwards in the vertical guide track towards the top end of the tubular sleeve, thereby moving the syringe barrel and syringe needle towards the top end of the tubular sleeve. The needle is, thus, retracted back into the tubular sleeve.

The foregoing description has been limited to specific embodiments of this invention. It will be apparent, however, that variations and modifications may be made by those skilled in the art to the disclosed embodiments of the invention, with the attainment of some or all of its advantages and without departing from the spirit and scope of the present invention. For example, the tubular sleeve can be made out of any suitable plastic or metal or a combination thereof. The guide pin and retaining slots can have various shapes or designs and still produce equivalent functions described herein. The tubular sleeve of the present invention can be adapted for any type of syringe. Any suitable type of biasing member, in addition to the spring, may be used. The tubular sleeve can also be used without a biasing member by a user pulling the syringe barrel towards the top end of the tubular sleeve after the guide pin has been rotated into the vertical guide track. Although the syringe barrel is described as being rotated relative to the tubular sleeve it is equivalent to rotating the tubular sleeve relative to the syringe barrel.

It will be understood that various changes in the details of the method and materials which have been described and illustrated above in order to explain the nature of this invention may be made by those skilled in the art without departing from the principle and scope of the invention as recited in the following claims.