Blood syringe

Details Blood syringe Blood syringe

2000-02-23

2001-07-24

Lacyk, John P. (Department: 3736)

Surgery

Diagnostic testing

Liquid collection

C604S110000

Reexamination Certificate

active

06264620

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a blood syringe, and more particularly to a blood syringe with a ratchet device to prevent the piston from detaching from the plunger while drawing blood.
2. Description of Related Art
As shown in
FIG. 5
, a conventional blood syringe in accordance with the prior art comprises a hollow barrel (
50
) with a connecting block (
51
), a plunger (
60
) with a piston (
61
) and a cap (
70
). The plunger (
60
) is received in the hollow barrel (
50
) and partially extends through the hollow barrel (
50
). The cap (
70
) closes the end of the connecting block (
51
) on the hollow barrel (
50
) opposite to the plunger (
60
).
An external thread (
501
) is formed on one end of the hollow barrel (
50
) and an internal circular flange (
502
) is formed inside the other end. The connecting block (
51
) has an open end and a closed end. The inside of the open end of the connecting block (
51
) is threaded and screws onto the external thread (
501
) on the hollow barrel (
50
). The closed end of the connecting block (
51
) includes a hollow needle hub (
512
) extending out from the center of the closed end and a flange (
511
) extending longitudinally out from the closed end around the needle hub (
512
). A through hole (
513
) is defined in the end of the needle hub (
512
). The through hole (
513
) communicates with the open end of the connecting block (
51
).
A male thread (
602
) is formed on one end of the plunger (
60
) and a button (
603
) is formed on the other end. A neck (
601
) is formed between the male thread (
602
) and the plunger (
60
). The plunger (
60
) is broken off at the neck (
601
) after drawing blood has been completed. The piston (
61
) has a hollow stub (
611
) extending from one end with an internal female thread (not numbered).
The cap (
70
) includes an open end to snugly fit over the flange (
511
) of the connecting block (
51
) and a closed end having a prong (
71
) extending inward. The prong (
71
) extends through the through hole (
513
) of the needle hub (
512
) when the cap (
70
) is attached to the connecting block (
51
).
However, carelessness by the technician while drawing blood may cause the piston (
61
) to detach from the plunger (
60
), and the blood in the hollow barrel (
50
) will flow back into the examinee's body. Also, since the cap (
70
) is simply pressed onto the connecting block (
51
), the cap (
70
) can easily be detached from the connecting block (
51
) if bumped.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional blood syringe.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a blood syringe with a ratchet device is provided. The plunger of the blood syringe has a male thread formed on one end. The base of the thread forms a ratchet wing having a vertical side and an inclined side along the male thread. A piston having a hollow stub extending from one end is slidably mounted in a hollow barrel. A female thread is defined in the stub to receive the male thread on the plunger. The top of the stub defines a ratchet stop having a vertical side and an inclined side each opposite to the vertical side and the inclined side of the ratchet wing. The ratchet wing and the ratchet stop are engaged with each other after the plunger screws into the stub so that the plunger can't reverse and detach from the piston.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.


REFERENCES:
patent: 3951146 (1976-04-01), Chiquiar-Arias
patent: 5370620 (1994-12-01), Shonfeld
patent: 5540660 (1996-07-01), Jenson

Affiliated with

Also associated with

Rating

Blood syringe does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Blood syringe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Blood syringe will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2526822