MXPA97001608A - A syringe of seguri - Google Patents

Abstract

A safety syringe is described. The syringe includes a syringe barrel, a movable arm, a needle, a needle collar and a push rod. At one end, the driving rod is attached to the needle collar while the other end protrudes slightly at the edge of the needle of the syringe barrel. When the injection is administered to the patient, the mobile arm travels all the way to the edge of the needle of the syringe barrel. The movable arm touches the push rod which causes the collar to automatically cover the tip of the needle as the injection is applied

Description

DESCRIPTION A SAFETY SYRINGE TECHNICAL FIELD The present invention relates, generally, with syringes, and in particular with syringes designed to protect the needle of the syringe to prevent it from being accidentally keyed. DESCRIPTION OF THE PREVIOUS TECHNIQUE In the medical field the prevention of accidental nailing of used needles is a constant concern. In a number of places innumerable injections are practiced by syringes every day. As with all other medical procedures, the prevention of infection is a primary concern. Typically the syringes are packed with a protective cover over the needle. The operator eliminates this cover before administering the injection. If the syringe is not already full, the operator will withdraw the medication, which is in the form of liquid, into the syringe. The fluid is drawn into the syringe by inserting the needle into the container of the medication liquid. The plunger of the syringe is extracted from the tip of the needle of the barrel of the syringe, creating a vacuum in the syringe. The vacuum causes the medication to be drawn into the syringe through the needle. The operator observes the position of the syringe plunger in relation to the volume markings on the body of the syringe. When the plunger reaches the desired mark that corresponds to the correct dose, the operator removes the needle from the container and holds the syringe, with the needle facing up, so that all the air in the syringe comes out of the needle. The operator then pushes the plunger slightly, sometimes tapping lightly on the side of the syringe, until all the air in the syringe is purged through the needle. The operator puts the syringe apart and prepares the injection site. Once the injection site is prepared, the operator inserts the needle into the patient and pushes the plunger injecting the medication towards the patient. When the plunger is fully pushed into the body of the syringe, the operator removes the needle from the patient. The following moments are crucial in the control of the infection. The syringe used, immediately after being removed from the patient, is commonly known as a dirty needle. Frequently, hospital offices and doctors have special receptacles in patient and examination rooms to remove dirty needles. The operator usually replaces the cover on the needle and places the syringe in the appropriate receptacle. But between the few moments, or even a few seconds, between taking the patient's syringe and placing the cover over the needle, it may happen that the dirty needle is accidentally keyed. Due to the hazards associated with this procedure, OSHA prohibited the practice of manually replacing needle covers. However, this prohibited practice is still common, and there is no safe and convenient alternative. Dirty needle sticks can occur during this time for several reasons. In emergency rooms and other places, the patient may be struggling with the treatment, and may push the used needle toward the operator or other medical professionals around the patient. Children, and even some adults, are frightened by the pain of an injection and may react, involuntarily or voluntarily, by pushing or doing any other movement that may result in accidental nailing. Other factors not attributable to the patient include operator fatigue, poor lighting conditions (ie, at night, in a patient's room in the dark), and simple oversights in the procedures that follow. Some of these conditions can cause the operator to nail the needle simply by replacing the needle cover. Numerous attempts were made to provide a device that can prevent or minimize the nailing of dirty needles. U.S. Patent Number 4No. 973,316 to Dysarz discloses a syringe wherein a compressed spring assembly is used within the barrel of the syringe in combination with a trigger assembly. The device in Dysarz retracts the needle as soon as the injection is delivered. However, the device in Dysarz requires the use of numerous moving parts and an internal spring in the body of the syringe. The device in Dysarz also requires the separate manipulation of the syringe by the operator after applying the injection. Dysarz does not reveal automatic protection of the needle with the administration of the injection. What is needed is a syringe that automatically covers the needle when administering the injection. An ideal syringe would cover the needle without the operator having to use a second hand and cover the needle simultaneously when applying the injection. The automatic cover feature should not interfere with the ability of the syringe to perform all the functions of a conventional syringe, to include the ability to draw medications and purge air from the medication. DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION It is an object of the present invention to provide a syringe that automatically covers the needle when the injection is applied to the patient.

Another object of the present invention is to provide a syringe that realizes the automatic cover of the needle without the operator needing to use two hands. Another object of the present invention is to provide a device that is compatible with current medication packages, specifically, the syringe must be capable of extracting drugs and purging the medically extracted air. Another objective of the present invention is to provide a device that is relatively easy and inexpensive to manufacture, and that is simple to operate. SUMMARY OF THE INVENTION A safety syringe is revealed. The syringe includes a syringe barrel, a plunger, a needle, a needle guard, and a push roller. The push roller is attached to the needle guard at one end, while at the other it protrudes slightly towards the needle end of the barrel of the syringe. When the plunger is fully inserted in the barrel to administer an injection, the plunger moves the push roller. The push roller in turn moves the guard to a position where the guard covers the needle. An advantage of the invention is that it automatically covers the pointed end of the needle of the syringe, as the operator applies the injection.

A further advantage of the invention is that the cover is automatically closed on the pointed end of the needle of the syringe, as the operator applies the injection. A further advantage of the invention is that the operator does not need to use two hands to cover the needle or to place the cover in its position. A further advantage of the invention is that the syringe can be used conventionally to extract drugs. A further advantage of the invention is that it is relatively inexpensive and easy to manufacture, and its operation is very simple. These and other objects, features and advantages of the present invention will be apparent from the following description of the invention. DESCRIPTION OF THE DRAWINGS Figure 1 is a sectional view of the invention with the protector in the exposed position. Figure 2 is a sectional view of the invention with the guard in the covered position. Figure 3 is a sectional view of the safety arms extending from the barrel of the invention. Figure 4 is a sectional view of the resistant base extending from the protector of the invention.

Figure 5 is a sectional view of the invention with the guard placed in the secure position by the lock arms and the sturdy base. BEST MODALITY FOR CARRYING OUT THE INVENTION Referring to Figure 1, a sectional view of the safety syringe 100 with the guard in the exposed position is shown. The safety syringe 100 would probably be shipped and packaged with a removable cover (not shown). The main parts of the safety syringe 100 are the barrel 101, the plunger 105, the needle 108, the protector 111 and the connector 114. The barrel 101 is a hollow and elongated cylindrical member made of a rigid or semi-rigid material, such as plastic molded. The barrel 101 is transparent or translucent, so that the operator can see the medicament in the barrel 101. The barrel 101 has a plunger end 102 that is open to receive the plunger 105 and the end of the needle 103. The end of needle 103 is similar to the needle end of conventional syringes known in the art, except that it has an opening for connector 104. The opening of connector 104 may be of any shape, as long as its shape matches the shape of the needle. cross section of the connector 114, so that when the connector 114 is inserted into the opening of the connector 104 a liquid tight seal is formed. In the modality shown, the opening of the connector 104 is a cylindrical bore whose greater axis is parallel to the major axis of the barrel 101. The plunger 105 has an end 106 and a sheave end 107. The plunger 105 is an elongated, rigid or semi-rigid member, whose length is adapted so that the operator can fully insert the plunger 105 into the barrel 101 when pushing the blunt end 106. The plunger 105 will typically be constructed of molded plastic. The sheave end 107 is adapted so that when the sheave end 107 is inserted into the barrel 101, a liquid-tight seal is formed between the sheave end 104 and the barrel 101. The sheave end can be constructed with a Optional sheave or plurality of sheaves to form this liquid tight seal. Or, as shown, the end of the sheave 104 can be constructed without sheaves, a configuration wherein the end of the sheave has a size such that it corresponds to the internal dimensions of the barrel 101. The needle 108 is an elongated, rigid member and hollow, typically constructed of a strong metal, such as stainless steel. The needle 108 has a pointed end 109 that can puncture the patient. The opposite pointed end 109 is the end in the syringe 110 of the needle 108 which is rigidly connected to the end of the needle 103 of the syringe 101. The end of the syringe 110 can be fixed to the barrel 101 by any conventional method known in FIG. the technique, such as sticking it, or making the end of the syringe 110 with a projection that is perpendicular to the needle 108 and placed on the end of the needle 103 of the barrel 101. The safety syringe 100 includes the guard 111 which is a semi-rigid, hollow, elongated member slidably positioned on the needle 108. The shield 111 has a knitted cover end 112 and a connecting end 113. The shield 111 can be moved over the needle 108 between two positions, an exposed position shown in Figure 1, wherein the shield 111 covers essentially all of the needle 108, except for a small portion of the needle 108 at the pointed end 109, and a position securely shown in Figure 2, wherein the shield 111 covers essentially all of the needle 108, including the pointed end 109. The insertion of the connector 114 into the opening of the connector 104 prevents rotation of the shield 111 around the needle 108. Connector 114 passes through connector opening 104. Connector 114 is an elongated, rigid or semi-rigid member having a protective end 115 at the end of barrel 116. Barrel end 116 is adapted to have the same shape of cross section that the opening of the connector 104, so that the end of the barrel 115 is slidably inserted through the opening of the connector When the shield 111 is in the exposed position the end of the barrel 115 protrudes into the barrel 101 at a distance default In the mode shown, this predetermined distance is approximately six millimeters. However, the person skilled in the art can practice the invention where this distance is greater or less than six millimeters. The end of the shield 115 of the connector 114 is connected to the shield 111 so that the 105 is inserted into the barrel 101, the roller end 107 will come into contact with the connector 114 which will cause the shield 111 to move towards the secure position. In the embodiment shown, connector 114 and shield 111 form a unitary member, but the person skilled in the art can practice the invention so that shield 111 and connector 114 are separate members. Although in the embodiment shown, shield 111 is made of Teflon and connector 114 is made of molded plastic, any semi-rigid material can be used for shield 111, and any rigid or semi-rigid material for connector 114. Additionally, although in the embodiment shown only the connector 114 is shown, the invention could be practiced with two or more connectors. The connector 114 and the connector opening 104 are adapted so that they can form an airtight seal to those adapted to form a liquid tight seal, while allowing the connector 114 to slide in and through the opening. of the connector 104. In the embodiment shown, this liquid-tight seal is achieved by using an inner ring 120 that matches between the connector 114 and the connector opening 104. Those skilled in the art can also practice the invention without the ring interior 120. Without the inner ring 120, the liquid tight seal could be achieved by making the connector 114 and the opening of the connector 104 have the proper size. The connector 114 includes the latch 121 at the end of the barrel 116. The latch 121 prevents the connector 114 and the protector 111 from being removed from the barrel 101 when the safety syringe is removed from the patient. In the embodiment shown, the safety 121 is a small integral projection to the connector 114, but those skilled in the art can practice the invention where the safety 121 is a protrusion completely surrounding the connector 114, or using any conventional device to prevent that the connector 114 comes fully out of the opening to the connector 104. In order to allow the medicament to be drawn into the safety syringe 101, as long as it continues to preserve the automatic cover feature of the needle of the safety syringe 100, one or more stopping devices 118 are fixedly placed on the inner wall 117 of the barrel 101. The stop devices 118 are the end of the needle with the intermediate placed 103 and the piston end 102 of the barrel 101. The devices of stop 118 are adapted so that the stop devices 118 are attached to the sheave end 107 to prevent the plunger 105 from passing beyond the device. and stop 118 and move the connector 114. The stop devices are also adapted in such a way that if the operator applies sufficient force, the pulley 107 can travel past the device 118 and move the connector 114, which in turn moves the protector 111 from the position exposed to the safe position. In the embodiment shown, the stopping devices 118 are one or more tips 119. The tips 119 are deformable plastic members projecting from the inner wall 117 at a distance sufficient to be attached to the sheave end 107. When the operator applies Sufficient force at the blunt end 106 of the plunger 105, the tips 119 deform and bend, thereby allowing the roller end 107 to travel all the way to the needle end 103 of the barrel 101, causing the guard 101 to move towards the safe position. Although in the embodiment shown, stop devices 118 are tip 119, those skilled in the art can make stop devices 118 by making a barrel 101 of smaller diameter at the needle end 103, and making a roller end 107 , with deformable members two diameters. The stop devices 118 could also be a sliding projection, perpendicular to the major axis of the barrel 111, where the protrusion could be adapted so that the operator could push it towards the barrel or remove it from the barrel, or any other conventional device to selectively stop the travel of the plunger of the syringe in the barrel of the syringe. The stop devices 118 are positioned at a sufficient distance from the end of the needle 103 of the barrel 101, to allow the connector 114 to enter the barrel 101 without being moved by the roller end 107. Due to this space, there will already be something of air in the safety syringe 100 when the fluid is drawn into the safety syringe 100. The operator must then purge the air from the safety syringe 100 using the conventional method of vertically holding the safety syringe with the needle 108 pointing towards above, and pressing the plunger 105 towards the barrel 101 until the air is extracted from the needle 108. The stop devices 119 can not be placed so far from the end of the needle 103 of the barrel 101, that an extraordinary amount of air must be removed from the barrel. the safety syringe 100 after extracting the medication. The air must be capable of being expelled by moving the plunger 105 towards the end of the piston 102 of the barrel 101 without moving the sheave end 107 past the stop device 118. In most conventional syringes known in the art, there is Marks on the barrel of the syringe to indicate the volume measurements of the liquid in the syringe. The safety syringe 100 will have volume markings 201 along the barrel 101, which will indicate the amount of fluid that was drawn into the barrel 101. The volume markings 201 will include the zero mark 203 and at least one unit mark 202. The zero mark will be aligned with the stop device 118. In the embodiment shown, the zero mark 203 could be eliminated, and the tips 119 used as the zero mark 203. The zero mark 203 and the unit marks 202 can be made by lines painted or etched into the barrel 101. In order to allow the guard 111 to be in the safe position, a pair of lock arms are attached to the end of the barrel needle 103. The first arm 300 has a barrel end 301 and a needle end 302. The first arm 300 also has an inner surface 303 and an outer surface 304. The longitudinal axis of the first arm 300 is essentially parallel to the longitudinal axis of the barrel 101. The second arm 400 has a barrel end 401 and a needle end 402. The second arm 400 also has an inner surface 403 and an outer surface 404. The second arm 400 is longer than the first arm 300. The arms 300 and 400 will typically be made of plastic molded, and integrally attached to the barrel 101. A first detent 305 is attached to the needle end 302 of the first arm 300. The first detent 305 extends inwardly from the end of the needle 302 of the first arm 300 to the needle 108, and the longitudinal axis of the first detent 300 is substantially perpendicular to the longitudinal axis of the barrel 101. The first detent 305 has a barrel surface 306 and a needle surface 307. The first detent 305 also has an arm end 308 and a free end. 309. The free end 309 of the first detent 305 is bevelled, so that the barrel surface 306 of the first detent 305 is shorter than the needle surface 307 of the first detent 305. A second The detent 405 is attached to the needle end 402 of the second arm 400. The second detent 405 extends inwardly from the needle end 402 of the second arm 400 to the needle 108, and the longitudinal axis of the second detent 405 is essentially perpendicular to the longitudinal axis of the barrel 101. The second detent 405 has a barrel surface 406 and a needle surface 407. The second detent 405 also has an arm end 408 and a free end 409. The retainers 305 and 405 will typically be made of plastic molded, and will be integrally attached to the arms 300 and 400, one to each arm. The free end 409 of the second detent 405, and the free end 309 of the first detent 305 defines a detent gap 350. The distance from the needle end of the barrel 103 to the first detent 305 must be greater than or equal to the distance that the guard 111 must move to reach the safe position. The difference between the distance of the second detent 405 to the barrel needle end 103, and the distance of the first retainer 305 to the barrel needle end 103, must be at least the thickness of the brow unit 133, but can not be be as large as to allow the shield 111 to come out of the pointed end 109 of the needle 108. A sturdy base 130 is integrally attached to the connector end 113 of the shield 111. The base 130 is conical in the embodiment shown; however, it can be replaced by other geometric designs. The base 130 has a connector end 131 and a protective end 132. An eyebrow unit 133, integral with the base 130, extends from the connector end 113 of the base 130. By virtue of the fact that the base 130 is a cone , the eyebrow unit 130 forms a ring, the eyebrow ring 134. Other obvious shapes for the eyebrow unit 133 can be substituted for the ring shape. The eyebrow unit 133 has a base edge 135 and a free edge 136. The diameter of the eyebrow ring 134, measured from the free edge 136, is greater than the width of the gap 350, but is less than or equal to the distance between the inner surface 303 of the first arm 300, and the internal surface 404 of the second arm 400. Of course, if another geometric configuration is used, the distance separating the elements comprising the eyebrow unit 133 must conform to the requirements stipulated herein in regard to diameter. By applying an inward force to the sturdy base 130, the width of the eyebrow unit 133 can be reduced, so that the eyebrow unit 133 can pass through the gap 350, as the shield 111 slides over the needle 108. At this point, the eyebrow unit 133 is positioned between the needle end of the barrel 103 and the first detent 305. As the connector 114 moves the sleeve 115 forward, it will move the base 130 and the brow unit 133 forward. . When the guard 111 has been moved to the secure position, the eyebrow unit 133 will join the barrel surface 306 of the first detent 305. As the free end 309 of the first detent 305 is beveled, it will allow the eyebrow unit 133 to pass through. . After the eyebrow unit 133 passes the first detent 305, the surface of the needle 307 of the first detent 305 will not allow the eyebrow unit 133 to back off. The barrel surface 406 of the second detent 405 will not allow the barrel unit 133 to pass beyond it. The eyebrow unit 133 is therefore secured between the first detent 305 and the second retainer 405. Since the brow unit 133 is integrally attached to the base 130, which in turn is integrally attached to the guard 111, the guard 111 It is secured in the safe position. Although in the modality shown there are two arms, the invention could be practiced using only one arm containing both spaces. More than two arms can be used to provide greater securing resistance. A ring containing both spaces could also be used. Other obvious variations in the modality could include the replacement of the resistant conical base with resistant wings each having an eyebrow at its end, or replacing the resistant conical base with any other geometric configuration. The safety syringe 100 is shipped in sterile packages, and will normally have a removable cover (not shown) on the needle 108 and guard 111. In operation, the operator removes the removable cover and inserts the needle 108 into a liquid container of medication. The operator pulls the plunger 105 in a direction away from the needle 108 so that the liquid is drawn into the barrel 101 until the roller end 107 is aligned with the appropriate markings of unit 202. The operator removes the needle 108 of the container. The operator pushes the needle towards the injection site in the patient. Once the needle is properly positioned in the patient, the operator pushes the blunt end 106 of the plunger 105, applying sufficient force to move the end of the pulley 107 of the plunger 105 past the stop device 118 toward the end of the needle 103 of the barrel 101. This movement causes the guard 111 to move from the exposed position to the secure position, while the pointed end 109 of the needle 108 remains on the patient. The operator removes the safety syringe 100 from the patient, and disposes of the safety syringe 100. The operation to cover the pointed end 109 of the needle 108 is therefore automatic, with the application of the injection, and is a one-handed operation. There are of course other alternative embodiments, which are obvious from the foregoing descriptions of the invention, and which are intended to be included within the scope of the invention, as defined in the following Claims:

Claims (5)

1. CLAIMS A safety syringe comprising: a barrel having a plunger end and a needle end, wherein the needle end has an opening for connector; a plunger having a blunt end and a sheave end, wherein the plunger and the sheave end are adapted such that the sheave end of the plunger can be inserted into the end of the barrel plunger, and form a hermetic seal to liquids between the sheave end and the barrel; a hollow needle having a pointed end and a syringe end, wherein the syringe end of the needle is rigidly connected to the end of the needle of the syringe; a protector slidably placed on the needle, wherein the protector has an end that covers the tip and a connector end, wherein the protector is movable from a position exposed to a secure position, wherein the exposed position is a position where the protector covers essentially the entire needle, including the pointed end; a connector having a protective end and a barrel end, wherein the protective end of the connector is operatively connected to the connector end of the shield, wherein the barrel end of the connector is slidably insertable through the connector opening, wherein the connector and the connector opening are adapted in such a way that a portion of the end of the barrel of the connector protrudes towards the barrel, wherein the connector and the protector are adapted in such a way that the sheave end of the plunger travels towards the end barrel needle, where the connector will move the protector from the exposed position to the safe position. The device of Claim 1, wherein the connector further comprises a latch on the barrel end of the connector, wherein the latch is adapted in such a way that the latch will be attached to the needle end of the barrel, as the plunger travels toward the barrel. Needle end of the barrel. The device of
2. Claim 2, further comprising an inner ring between the connector and the opening of the connector, wherein the inner ring, the connector, and the connector opening are adapted to form a liquid-tight seal. The device of
3. Claim 3, further comprising: an interior wall of the barrel; and one or more stop devices attached to the inner wall near the end of the barrel needle, and intermediate to the end of the needle and the end of the barrel plunger, wherein the stop devices are adapted to join and stop the travel from the sheave end to the needle end of the barrel, wherein the stop device is adapted in such a way that the sheave end can move past the stop devices when the operator applies sufficient force to the plunger. The device of
4. Claim 4, wherein the stop device is positioned such that the operator can draw fluid into the barrel, moving the plunger toward the plunger end of the barrel, and purging air from the liquid by pushing the plunger toward the barrel. needle end of the barrel, without moving the sheave end of the plunger past the stop device. The device of
5. Claim 5, wherein the barrel further comprises volume markings to indicate the amount of liquid that was drawn into the barrel, wherein the volume markings, including a zero mark, and at least one marking unit, in where the zero mark is aligned with the stop device. A safety syringe comprising: a barrel having a plunger end and a needle end, wherein the needle end has a connector opening; a plunger having a blunt end and a sheave end, wherein the plunger and the sheave end are adapted in such a way that the sheave end of the plunger can be inserted into the plunger end of the barrel and form a liquid tight seal between the sheave end and the barrel; a hollow needle having a pointed end and a syringe end, wherein the syringe end of the needle is rigidly connected to the needle end of the syringe; a protector slidably placed on the needle, wherein the protector has an end that covers the tip and a connector end, wherein the protector is movable from a position exposed to a secure position, wherein the exposed position is a position where the protector covers essentially all of the needle, leaving exposed only a small portion of the needle at the pointed end, where the secure position is a position where the guard covers essentially the entire needle, including the pointed end; a first arm extending from the needle end of the barrel, where the longitudinal axis of the first arm is essentially parallel to the longitudinal axis of the barrel, wherein the first arm has a barrel end and a needle end, wherein the first Arm also has an inner surface and an outer surface; a first detent extending inwardly from the needle end of the first arm towards the needle, wherein the longitudinal axis of the first detent is essentially perpendicular to the longitudinal axis of the barrel; the first detent has a barrel surface and a needle surface, wherein the first detent also has an arm end and a free end, wherein the free end of the first detent is bevelled so that the barrel surface of the first detent it is shorter than the needle surface of the first detent; a second arm extending the needle end of the barrel, where the longitudinal axis of the second arm is essentially parallel to the longitudinal axis of the barrel, wherein the second arm also has an internal surface and an external surface, wherein the second arm is longer than the first arm, where the barrel end of the second arm is placed at the needle end of the barrel, so that the opening of the connector is located between the barrel end of the second arm, and the barrel end of the first arm. arm; a second detent extending inwardly from the needle end of the second arm toward the needle, where the longitudinal axis of the second detent is essentially perpendicular to the longitudinal axis of the barrel; the second detent has a barrel surface and a needle surface, the second detent also has an arm end and a free end, wherein the free end of the second detent together with the free end of the first detent defines a detent gap; a sturdy base extending from the connector end of the protector, where the base has a connector end and a protective end; an eyebrow extending outwardly from the connector end of the base, essentially perpendicular to the longitudinal axis of the protector, thus forming an eyebrow unit, where the eyebrow unit has a base edge and a free edge, where the eyebrow unit it is adapted in such a way that the eyebrow unit can pass through the detent gap by applying a pressure towards the resistant base, as the protector is slidably placed on the needle, where the eyebrow unit can be placed between the first retainer and the needle end of the barrel; a connector having a protective end and a barrel end, wherein the protective end of the connector is operatively connected to the connector end of the shield and the base, where the barrel end of the connector is insertable slidably through the connector opening, wherein the connector and the opening of the connector are adapted in such a way that a portion of the barrel end of the connector protrudes towards the barrel, wherein the connector and the shield are adapted in such a way that as the sheave end of the plunger travels towards the barrel. Needle end of the barrel, the connector will move the protector from the exposed position to the safe position, wherein the connector, the protector, the base and the eyebrow unit are further adapted such that when the connector moves the protector to the secure position, the actuator will move the eyebrow unit extending from the base, beyond of the bevelled free end of the first detent, thereby securing the brow unit between the needle surface of the first detent and the barrel surface of the second detent, thereby securing the shield in the secure position. A method for administering an injection to a patient comprising: (1) Preparing a safety syringe for use, wherein the safety syringe comprises: (i) a barrel having a plunger end, an inner wall and an end of needle, where the needle end has a connector opening; (ii) a plunger having a blunt end and a sheave end, wherein the plunger and the sheave end are adapted in such a way that the sheave end of the plunger can be inserted towards the plunger end of the barrel and form a seal liquid tight between the barrel end of the barrel; (iii) a hollow needle having a pointed end and a syringe end, wherein the syringe end of the needle is rigidly connected to the needle end of the syringe; (iv) a protector slidably engageable on the needle, wherein the protector has a tip cover end and a connector end, wherein the protector is movable from a position exposed to a secure position, where the exposed position is a that the guard covers essentially the entire needle, leaving only a small portion of the needle exposed at the pointed end, where the secure position is a position where the guard essentially covers the entire needle, including the pointed end; (v) a connector having a guard end and a barrel end, wherein the guard end of the connector is operatively connected to the connector end of the guard, wherein the barrel end of the connector is slidably insertable through the opening of connector, wherein the connector and the opening of the connector are adapted in such a way that a portion of the barrel end of the connector protrudes towards the barrel, wherein the connector and the protector are adapted in such a way that the sheave end of the plunger travels to the needle end of the barrel, where the connector will move this shield from the exposed position to the safe position; and (vi) one or more stop devices attached to the inner wall near the needle end of the barrel, and intermediate between the needle end and the end of the plunger, wherein the stop device is adapted in such a way that the device The stopper is joined and stops the travel of the sheave end towards the needle end of the barrel, wherein the stop device is further adapted such that the sheave end can travel past the stop device when the operator applies sufficient force. (2) inserting the pointed end of the needle into the drug liquid container, and extracting a desired amount of liquid; (3) remove the needle from the container; (4) Insert the pointed end of the needle into the patient; (5) pushing the blunt end of the plunger with sufficient force to cause the sheave end of the plunger to travel past the stop device; (6) Continue pushing the blunt end to cause the guard to move from the exposed position to the safe position; and (7) remove the patient's safety syringe.