Patent ID: 7232428

Claim:
A cock for medical use, comprising: a valve body having a switching part formed in a valve shaft thereof for switching from one flow passage to another by operation of a handle; and a main body in the form of a bottomed cylinder having an internal chamber in which the valve shaft of the valve body is rotatably fitted, and three tributary tubes each having a lumen extending therethrough, the lumen opening on a side wall of the internal chamber; the valve body being rotated through the handle to alternately bring the lumens into communication with one another through the switching part and thereby switch flow of an infusion fluid from one flow passage to another; wherein one of the tributary tubes is a patient side tributary tube for connection to the patient and other two tributary tubes are source side tributary tubes for connection to infusion sources; wherein one of the source side tributary tubes is made much shorter than the other source side tributary tube and the patient side tributary tube; and wherein the long source side tributary tube is arranged in line with the patient side tributary tube; wherein the short source side tributary tube is arranged at an angle of about 90° with respect to the other tributary tubes, and the short source side tributary tube is filled with a septum so as to substantially eliminate dead space in the tributary tube; and wherein the switching part is located right under the lumen of the short source side tributary tube, and wherein the switching part comprises a switching valve which has a cross section consisting of a semicircular closure portion along the circumferential surface of the valve shaft and a semicircular core portion with a smaller radius than the semicircular closure portion so as to form a switching channel in a form of an arcuate groove in the valve shaft.