Blood sampling syringe

This blood sampling syringe consists primarily of a cylinder, which removably receives an expandable encasement, that will receive a specimen by needle means. The upper structure of this syringe includes rotatable cylinder means for creating a vacuum, which will be controlled by an adjustable control valve. The control valve enables the user to utilize as much of the vacuum needed to collect a specimen within the disposable and expandable encasement.

This invention relates to hypodermic syringes, and more particularly, to a 
vacuum type hypodermic syringe. 
It is, therefore, the principal object of this invention to provide a 
hypodermic syringe, which will be used to extract specimens under 
controlled conditions. 
Another object of this invention is to provide a syringe of the type 
described, which will produce a vacuum to extract specimens, while, 
simultaneously, greatly reducing the chance of accidentally injecting air 
into the circulatory system. 
A further object of this invention is to provide a syringe, of the type 
described, which will employ the use of an expandable encasement, which is 
disposable, as according to the teachings of Samuel L. Chapman, U.S. Pat. 
no. 3,161,194. 
A still further object of this invention is to provide a syringe of the 
type described, which will employ the use of rotary motion to produce a 
vacuum. 
Other objects of the invention are to provide a blood sampling syringe, 
which is simple in design, inexpensive to manufacture, economical to 
operate, rugged in construction, easy to use and efficient in operation.

According to this invention, a blood sampling syringe 10 is shown to 
include a classic cylinder 11, which is externally threaded, one end 
threadably receiving a cap, 12 having a hollow needle 13 therein. A 
plastic encasement 14, of accordian-like configuration, is expandable by 
vacuum means, within the cylinder bore 11a. Encasement 14 is fixedly 
secured by its end wall 15, in a suitable manner, within cap 12, and the 
end wall 16 is freely and slideably received within the bore 11a of 
cylinder 11, when vacuum is produced within bore 11a. 
A cylindrical control valve body 17 is threadably received on the opposite 
end of cylinder 11, and an opening 18 within valve body 17 enables air to 
be withdrawn from cylinder 11. A valve screw 19, having a head 20, is of a 
suitable plastic material, for a purpose which hereinafter will be 
described. Valve screw 19 is provided with a conical end 21, which is 
removably received within recess 22, the conical end 21 serving as a means 
of restricting opening 18. Valve screw 19 is threadably received within 
opening 22a, which intersects opening 18, and valve screw 19 is of plastic 
material, so as to provide sealing means against air entering cylinder 
bore 11a. Bore 23 of body 17 is in longitudinal alignment with opening 18 
and the bore 11a of cylinder 11. Control valve body 17 includes an open 
end 24, and the recessed end wall 25, which abuts with cylinder 11, is a 
control valve assembly. An internally threaded cylinder 26 threadingly 
engages the externally threaded upper portion of body 17, and cylinder 26 
is provided with a shank portion 27, which is integral with and extending 
from end wall 28. A rubber or plastic disc 28a provides seal means, in a 
manner which hereinafter will be described. The annular opening 29 enables 
cylinder 26 to be threaded downwards to the control valve assembly, and 
enables shank 27 to rotatably engage with the bore 23. Disc 28a is fixedly 
secured to the end of shank 27 in a suitable manner, and is in rotatable 
engagement with bore 23, so as to prevent air from entering bore 23, past 
the threaded portion of cylinder 26 and control valve body 17. 
In use, cylinder 26 is first rotated downwards upon the control valve body 
17, to its stopping point, after valve screw 19 is rotated outwards of 
control body 17, so as to have air at atmosphere pressure within syringe 
10. Valve screw 19 is then rotated until it seals off opening 18. Cylinder 
26 is then rotated upwards on control valve body 17, which by means of 
shank 27 and disc 28a will cause a vacuum to be created in bore 23. The 
valve screw 19 can then be rotated outwards, so as to release this energy 
source, at will, to cause the collapsible encasement 14, to fill with the 
specimen obtained through the needle 13 means. 
As shown in FIG. 2 of the drawing, a modified form of valve assembly 30 is 
shown to include a cylinder 31, having a recessed end wall 32, through 
which is an opening 33. A conically configurated valve 34 is seatable over 
opening 33, and valve 34 has, secured on its stem 35, a control knob 36, 
for the rotation thereof. A disc 37 is fixedly secured, in a suitable 
manner, within cylinder 31, and is spaced apart from the recessed end wall 
32. An offset passage opening 38 through disc 37 provides for vacuum 
passageway means through cylinder 11. The upper portion 39 is similar to 
valve body 17, of the heretofore described embodiment of the present 
invention, with the exception, that a rubber or plastic seal 40 is secured 
within the end wall 40a of cylinder 41, so as to provide shield means for 
stem 35, which is rotatably received within the opening 42 of the shank 
43, which has secured fixedly thereto, a rubber or plastic disc 44 which 
serves as seal means for the shank 43 and the cylinder 31. 
The means for creating a vacuum with valve assembly 30, is similar to that 
described of FIG. 1 of the drawing, with the exception, that control knob 
36, through the valve 34 means, may control the vacuum as desired through 
the opening 33, the passage 38, and the bore 45.