DISPOSABLE SYRINGE NEEDLE ATTACHMENT HUB

摘要

The present invention provides a safety syringe having a syringe cylinder with a proximal end and a distal end, a piston stem for insertion in the proximal end of the cylinder, a needle cannula capable of being retracted in a proximal direction into said syringe cylinder, and a needle cannula attachment hub capable of attachment to the syringe cylinder. An interior configuration of the hub includes an interference portion in an adhesive area of the hub, the adhesive area filled with adhesive to releasably attach the cannula to the hub. The interference portion has a contact surface and a distal surface with the angle between the contact surface and the hub wall less than the angle between the distal surface and the hub wall so that a greater force applied on the cannula in a distal direction is required to separate the cannula from the hub as compared to the force required to be applied on the cannula in a proximal direction to separate the cannula from the hub. In an alternate embodiment the interior configuration of the hub includes a narrow distal portion which may include a plurality of annular grooves and an enlarged well area disposed proximal thereto. The well area and the annular grooves are filled with an adhesive for releasably attaching the needle cannula to the hub. A plug member formed of a relatively soft resilient material may be received within the piston void between a distal end of the piston stem and the needle capturer. The plug member maintains proper alignment of the capturer and seals-off a portion of the lateral port of the needle cannula and the proximal opening of the needle cannula after it has passed through the capturer.