1. Field of the Invention
The present invention relates to an automatic retractable safety syringe, and more particularly to an automatic retractable safety syringe including a simplified structure that may be easily and quickly manufactured and assembled and that may include a greatly reduced or decreased manufacturing cost and that may be easily actuated or operated by the user.
2. Description of the Prior Art
Typical syringes comprise a piston slidably received or engaged in an outer cylindrical member or barrel, and a piston rod attached or mounted or secured or coupled to the piston for moving the piston along or relative to the cylindrical member or barrel, and for selectively drawing the fluid or medicine into and out of the cylindrical member or barrel.
Due to the recent advent of the AIDS virus, which may be contracted by contaminated hypodermic syringes, there have been several retractable needle hypodermic syringes invented and patented.
For example, U.S. Pat. No. 5,785,687 to Saito, U.S. Pat. No. 6,093,171 to Huang, U.S. Pat. No. 6,196,997 to Saito, and U.S. Pat. No. 6,482,174 to Tiu disclose several of the typical retractable safety syringes each comprising a hollow plunger slidably received or engaged in an outer cylindrical member or barrel, and a piston slidably received or engaged in the plunger for retracting the needle into the plunger after use.
However, in the typical retractable safety syringes, the users have to draw the needle into the plunger after use by themselves, and the needle may not be drawn into the plunger automatically without being operated by the user.
U.S. Pat. No. 7,476,215 to Lam discloses one of the typical automatic retractable safety syringes comprising a hollow plunger slidably received or engaged in an outer cylindrical member or barrel, and a piston slidably received or engaged in the plunger, and a piston vacuum seal required to be attached or mounted or secured to the distal end of the piston, the relative axial movement of the plunger in relation to the piston causes a vacuum to be created within the plunger.
However, the typical automatic retractable safety syringes comprises a number of parts or elements that are required to be precisely assembled. In addition, the piston vacuum seal that is attached or mounted or secured to the distal end of the piston has a good chance to be tilted or inclined relative to the plunger, and the vacuum created within the plunger may have a good chance to become failure.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional automatic retractable safety syringes.
The primary objective of the present invention is to provide an automatic retractable safety syringe including a simplified structure that may be easily and quickly manufactured and assembled and that may include a greatly reduced or decreased manufacturing cost and that may be easily actuated or operated by the user.
In accordance with one aspect of the invention, there is provided a syringe comprising a barrel including a chamber formed therein, and including an opening formed in a first end portion thereof, and including a mouth formed in a second end portion thereof, a needle seat engaged in the mouth of the barrel and including a needle attached to the needle seat, a plunger slidably engaged into the opening and the chamber of the barrel, and including a first end portion located out of the barrel, and including a compartment formed therein, and including a second end portion, and a packing releasably engaged into the compartment at the second end portion of the plunger for forming a vacuum within the plunger, and an engaging member attached to the packing and extended out of the plunger for selectively engaging with the needle seat and for selectively moving the needle seat and the needle into the compartment of the plunger, and the packing and the engaging member are forced to move relative to the plunger and to spoil a releasable engagement between the plunger and the packing when the plunger is forced and moved toward the needle seat, and the packing and the engaging member and the needle seat and the needle are automatically drawn into the compartment of the plunger by the vacuum of the plunger when the packing is forced to move relative to the plunger.
The barrel includes a gasket engaged into the chamber of the barrel and located close to the mouth of the barrel for engaging with the second end portion of the plunger and for selectively applying a reaction force onto the packing and the engaging member when the plunger is forced and moved toward the needle seat.
The plunger includes an insert engaged into the compartment at the first end portion of the plunger for forming the vacuum within the plunger and between the insert and the packing. The insert is secured to the barrel with a fastener or lock or latch device. The insert includes a sealing ring engaged with the plunger for making a fluid tight seal between the insert and the plunger.
The plunger includes a sealing ring disposed on the second end portion of the plunger and engaged with the barrel or engaged between the plunger and the barrel for making a fluid tight seal between the barrel and the plunger.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
Referring to the drawings, and initially to
A needle 20 is attached or mounted or secured to a needle seat 21, or includes a needle seat 21 attached or mounted thereto and releasably disposed or engaged into the mouth 14 of the barrel 10, and movable or engageable into the chamber 11 of the barrel 10 (
The plunger 30 is slidably received or engaged in the chamber 11 of the barrel 10, and includes a first or one end portion 31 extended or located out of the barrel 10, and includes a bore or longitudinal compartment 32 formed therein, and includes a gasket or sealing ring 33 disposed or engaged onto the outer peripheral portion of the second or other end portion 34 of the plunger 30 and contacted or engaged with the barrel 10 for making an air or water or fluid tight seal between the barrel 10 and the plunger 30.
A filling or sealing member or insert 40 is disposed or engaged into the compartment 32 at the one end portion 31 of the plunger 30 and attached or mounted or secured or anchored or retained to the barrel 10 with a fastener or lock or latch device 41, and includes a gasket or sealing ring 42 contacted or engaged with the plunger 30 for making an air or water or fluid tight seal between the insert 40 and the plunger 30.
A packing 50 is disposed or engaged into the compartment 32 at the other end portion 34 of the plunger 30 and releasably attached or mounted or secured or anchored or retained to the plunger 30 with a force-fitted engagement, for forming or defining or creating a vacuum 80 within the plunger 30 and between the insert 40 and the packing 50, and an extension or actuator or engaging member 51 is attached or mounted or secured to the packing 50 and partially extended out of the plunger 30 (
In operation, as shown in
As shown in
Simultaneously, when the other end portion 34 of the plunger 30 is forced or moved or pressed onto the soft or resilient gasket 16, and when the engaging member 51 is further forced or moved or pressed to engage with the needle seat 21 that is engaged in the mouth 14 of the barrel 10 (
It is to be noted that the automatic retractable safety syringe in accordance with the present invention includes a simplified structure having the insert 40 and the packing 50 engaged into the compartment 32 of the plunger 30 for forming or defining or creating a vacuum 80 within the plunger 30, and the plunger 30 may then be easily and quickly disposed or engaged or assembled into the chamber 11 of the barrel 10, and the automatic retractable safety syringe may be easily used or operated as that of the typical syringes.
Accordingly, the automatic retractable safety syringe in accordance with the present invention includes a simplified structure that may be easily and quickly manufactured and assembled and that may include a greatly reduced or decreased manufacturing cost, and that may be easily actuated or operated by the user.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.