1. Field of the Invention
The present invention relates to hypodermic needles and more particularly to an improved safety syringe being highly adaptable to one of a variety of syringe plungers or intravenous (IV) adapters.
2. Description of Related Art
There is no hypodermic needle currently on the market that completely and satisfactorily solves the safety problem from accidentally pricking after its use and thereby contaminating the medical worker with microorganisms or blood on the needle. For example, U.S. Pat. No. 6,093,170 disclosed a structure safety syringe comprising a barrel 10, a plunger 20, and a sleeve 30 in which the barrel 10 and the plunger 20 are well known devices. The patent is characterized in that a tab 13 is disposed near a hypodermic needle 12 on a circumferential surface of the barrel 10, a U-shaped guide slot 33 is disposed lengthwise along a wall of the sleeve 30, and an insertion section 35 aligned with the tab 13 is formed at interior ends of the guide slot 33. However, the sleeve 30 is not safe in use due to the following reasons: The sleeve 30 is made of plastic by injection molding. The insertion section 35 is not able to seal the tab 13 completely because the insertion section 35 has an inherent flexibility of the plastic. Hence, the tab 13 can be advanced again for at least a second dispensing of fluid after its use. As a result, the claimed safety feature is compromised. For accommodating the barrel 10 and the sleeve 30 and facilitating a smooth sliding of the tab 13 along the guide slot 33, a size of the barrel 10 is required to modify for overcoming the adverse affection caused by provision of the tab 13. As such, the barrel 10 is not readily adapted to the conventional international specification. However, the modification of the barrel 10 is costly due to a high price molding. In addition, a compatibility of the barrel 10 with other similar products is very low. That is, the barrel 10 cannot be used as a replacement of any of other commercially available syringe barrels. Additionally, in response to the modification of the barrel 10, issues such as an acceptable smoothness of the barrel 10 sliding in the plunger 20, tightness, and safety have not be satisfactorily solved by the patent. Hence, a need for improvement exists.
It is an object of the present invention to provide a highly adaptable safety syringe in which a retractable needle retracts within a sheath and locks in a lock slot of the sheath immediately after fluid dispensing so that a second advancing of the contaminated needle for dispensing fluid again is prohibited. By utilizing this syringe, safety in dispensing fluid by a medical worker is greatly increased.
It is another object of the present invention to provide a highly adaptable safety syringe in which the sheath is adapted to couple to one of a variety of typical syringe plungers or IV infusion sets by means of the adapter without modifying the plunger or the IV infusion set, thereby greatly increasing compatibility and adaptability of the invention.
It is a further object of the present invention to provide a highly adaptable safety syringe comprising a plunger, a hollow cylindrical, staged adapter fitted on a forward nose of the plunger, a projection on a circumference of the adapter, a hypodermic needle mounted on a forward end of the adapter, and a sheath for enclosing the adapter and the needle, the sheath comprising a T-shaped groove so as to define a sliding of the projection therealong and cause the needle to extend through a forward aperture of the sheath for dispensing fluid or lock the projection therein.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
Referring to
The projection 34 is shaped as one having a lower forward side, a higher rearward side, a lower right side, a higher left side, and a section of D. As such, the projection 34 is facilitated to fit in the sheath 20 and lock in a lock slot 225 of the sheath 20. In detail, the projection 34 comprises a first side of D shape 341, a second side of trapezoidal shape 342, a third side of D shape 343, a fourth side of trapezoidal shape 344, a square top 345, and a square, flat bottom 346. The area of the first side 341 is larger than that of the second side 342. The area of the second side 342 is larger than that of the third side 343. The area of the third side 343 is larger than that of the fourth side 344. The top 345 is arcuate downward from the higher second side 342 to the lower fourth side 344. Also, the top 345 is arcuate downward from the higher first side 341 to the lower third side 343. Such projection 34 is thus facilitated to slide to lock in the lock slot 225 as detailed later.
As shown in
In assembly, fit the adapter 30 on the forward nose 11 of the plunger 10. Next, fit the needle housing 42 on the second cylindrical section 33. Finally, put the sheath 20 on the adapter 30 for covering the needle unit 40 and the projection 34 which is also defined in the groove 220. As such, the needle 41 is allowed to extend or retract through the sheath 20.
Referring to
After fluid dispensing, simply slide the projection 34 rearward along the groove 220 from the forward stop 221F to the recess 224 via the rearward intersection 221R and the horizontal portion 222. At this position, the needle unit 40 is again concealed in the sheath 20. A clockwise rotation of the adapter 30 with respect to the sheath 20 will cause the projection 34 to move from the recess 224 (
One purpose of the syringe of the invention is to prevent a second advancing of the once contaminated needle 41 from dispensing fluid again after its use. For this reason, the recess 224 of the left vertical portion 221 of the T-shaped groove 220 is shaped to conform with the projection 34 and the right horizontal portion 222 thereof is formed as the intermediate cross piece 227 and the lock slot 225 which is also shaped to conform with the projection 34. The sheath 20 is formed of plastic by plastic molding. As such, the elongate cross piece 227 has a good flexibility. Further, the cross piece 227 is formed integrally with the sheath 20. The cross piece 227 can maintain its strength during and after the process of moving the projection 34 into or away from the lock slot 225 by passing the projection 34 under the cross piece 227. Moreover, the arcuate top 345 of the projection 34 can facilitate the passing of the projection 34 under the cross piece 227. Note that once the projection 34 is locked in the lock slot 225 with the needle 41 concealed in the sheath 20 after dispensing fluid the needle 41 cannot be used again. This can completely prevent criminals from using the syringe again by simply cleaning the used needle.
Referring to
For describing the adaptability of the syringe of the invention, second, third, and fourth preferred embodiments will now be discussed in detail below.
Referring to
Referring to
Additional benefit of the invention includes: The sheath is adapted to couple to one of a variety of typical syringe plungers or IV infusion sets by means of the adapter without need of any modification or change or variation of the plunger or the IV infusion set, thereby greatly increasing compatibility and adaptability of the invention to the existing syringe plungers or IV infusion sets.
Moreover, the projection 34 can be formed as a cube or polygonal member, the groove 220 can be shaped as an L or I-shaped groove, or the rearward intersection 221R and the recess 224 can be formed as a single element in any of other embodiments.
While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.