Title of Invention

"SINGLE SHOT DISPOSABLE SYRINGE AND NEEDLE"

Abstract

This invention relates to single shot disposable syringe comprising: an outer shell; a rod movably fitted, in said shell; a stopper at the upper end of said shell; a protuberance having grooves at the lower end of said shell; characterized in that a holder having a piston at the lower end is provided with a lock slidably fitted in it, lower end of said rod is shaped to enable engagement of said lock with it when said rod is pulled out and to enable disengagement of said lock when said rod is pushed in.

Full Text

The subject invention relates to a disposable syringe which can be used only once. The object of the invention is to prevent the repeated use of syringes and the resultant spread of certain ineffective illness which currently afflict humanity. There is known to be an increasingly urgent requirement for syringes which can be used only once, i.e. which are unable to draw in new liquid once the original liquid initially drawn into the syringe has been injected. The problem of constructing syringes which can be used only once is very urgent, as is demonstrated by the large number of patents offering different solutions, such as those described in the patents as U.S. Patent No. 4,699,614 and GBP-A-2,205,750. Non-reusable syringes as designed in the past have various shortcomings as found in case of non-retractable drive shaft or piston arrangements such as found in U.S. Patent No. 4,493,703 where the syringes are pre-filled as the syringes were so designed that it was not filled by the user in the conventional manner. The Patent application PCT WO 88/10127, GB-A-2,015,883 and EP-A-0,325,886 describe syringes in which the plunger and its operating shaft are only weakly linked together i.e. can disengage and various expedients are provided to ensure that when the plunger has been pushed to the bottom of the cylinder by the action of the shaft, the shaft disengages from the plunger when the shaft is pulled. To retain the plunger more securely in the cylinder specially designated annular ribs are provided, making the syringe thus made to be very expensive and complicated to use. To overcome the above referenced problems, the syringe of subject invention has been devised, where the syringe is rendered ineffective to be used for the second time. STATEMENT OF THE INVENTION According to the present invention there is provided single shot disposable syringe comprising: an outer shell; a rod movably fitted in said shell; a stopper at the upper end of said shell; a protuberance having grooves at the lower end of said shell; . characterized in that a holder having a piston at the lower end is provided with a lock slidably fitted in it, lower end of said rod is shaped to enable engagement of said lock with it when said rod is pulled out and to enable disengagement of said lock when said rod is pushed in. DESCRIPTION OF THE ACCOMPANYING DRAWINGS Fig. 1 shows the side view of the syringe. Fig. 2 shows the cut side view of the rod, holder and the piston. Fig. 3 shows the side view of the needle Fig. 4 shows the side view of the attachment place of the needle. The syringe has an outer shell (1) in which runs a rod with a piston attached to it. The rod can be moved backward to draw the fluid from the ampule or the body of a patient and it can be moved forward to inject the same wherever required. These movements can be done only once. The shell (1) has a stopper (2) at the upper end, that is the end which is opposite to the end where the needle is fitted, which prevents the rod from being pulled out. The shell has a protuberance (3) at the other end where the needle is to be fixed. The rod (4) has three main parts. The first part is the piston (5) which does the sucking and the pushing operations when the rod is moved forward or backward. The second part is the holder (6) which does the job of holding together the piston and the main rod (7). This holder (6) has a lock (8) inserted in its wall. The lock shall move backwards when the rod is pushed in. The foremost part of the syringe has a protuberance (3) onto which the needle (9) is to be attached. The case (10) in which the needle is embedded, has grooves inside which are opposite in direction to the grooves of the protuberance (3) so that when the case of the needle is pushed onto the protuberance, both of these locks themselves to each other because of the grooves. WORKING OF THE SYRINGE When the syringe is to be used, the needle is pushed onto the protuberance. The grooves on both the components help to lock themselves with each other. The needle can now be inserted into the body of a patient or the ampule as the case may be. The rod is now pulled back to the extent that the required quantity of the fluid is sucked into the shell of the syringe. During the backward motion the lock in the holder has tied the main rod and hence the sucking is made possible because the other end of the holder holds the piston. To push the fluid out of the syringe, the rod is now pushed forward into the shell. The rod is so shaped that the body of the rod can slide into the holder only when the lock of the holder is pushed sideways. As the pressure on the rod increases, the rod makes its way into the holder while pushing the lock sideways. The end of the rod now rests on the body of the holder and further pressure pushes the piston forward ejecting the fluid out of the syringe. As the lock of the holder has now been pushed sideways it can no longer hold the edge of the rod. The rod and the holder thus become free and independent of each other. As they become free the rod can no longer pull the piston and hence suction of the fluid second time, becomes impossible. The stopper at the end of the shell ensures that no fiddling is possible with the rod or the holder. Hence the syringe can not be used second time at all. I CLAIM :- 1 . Single shot disposable syringe comprising: an outer shell; a rod movably fitted in said shell; a stopper at the upper end of said shell; a protuberance having grooves at the lower end of said shell; characterized in that a holder having a piston at the lower end is provided with a lock slidably fitted in it, lower end of said rod is shaped to enable engagement of said lock with it when said rod is pulled out and to enable disengagement of said lock when said rod is pushed in. 2. Single shot disposable syringe as claimed in claim 1, wherein said protuberance is provided with grooves to enable fitting of case of needle, the case being provided with grooves opposite in direction to the grooves in said protuberance. 3. Single shot disposable syringe as claimed in claim 1, wherein said lock disengagement frees the said holder and the said rod. 4. Single shot disposable syringe, substantially as hereinbefore described with the accompanying drawings.

Documents:

2894-del-1997-abstract.pdf

2894-del-1997-claims.pdf

2894-del-1997-correspondence-0thers.pdf

2894-del-1997-correspondence-po.pdf

2894-del-1997-description (complete).pdf

2894-del-1997-drawings.pdf

2894-del-1997-form-1.pdf

2894-del-1997-form-13.pdf

2894-del-1997-form-19.pdf

2894-del-1997-form-2.pdf

2894-del-1997-form-26.pdf

2894-del-1997-form-3.pdf

2894-del-1997-form-6.pdf