Valve apparatus for simultaneous control of a plurality of fluid paths

#The present invention is directed to a valve apparatus for simultaneous control of a plurality of fluid paths.

#In a typical fluid valving arrangement, especially for laboratory type devices, several fluid paths must be opened and closed simultaneously. A typical example of the way in which this is done is shown in U.S. Pat. No. 3,550,619, assigned to the present assignee, where a single rotatable shaft includes a number of cams, each associated with a particular flexible tube. A cam, when its surface is rotated, compresses the associated tube to close it. In a relatively simple device, with only a few flow paths, the above technique was adequate. However, where for example there are ten or more flow paths with associated tubes which must be opened and closed simultaneously, the foregoing structure becomes bulky and mechanically cumbersome in operation.

#It is thus an object of the present invention to provide an improved valve apparatus.

#FIG. 1 is a simplified perspective view, partially in phantom, of the valve apparatus embodying the present invention.

#FIG. 2 is a simplified side view of a portion of FIG. 1.

#FIG. 3 is a cross-sectional view of FIG. 2.

#The valving arrangement of the present invention is ideally used in a blood-platelet counting apparatus which is disclosed in patent application Ser. No. 780,402 filed Mar. 23, 1977 in the name of John L. Haynes, assigned to the present assignee, and now patent number 4,165,484. As shown in that patent, several fluid flow paths must be controlled simultaneously by several valves, as also illustrated in the table of FIG. 8 of the present invention. The valves are designated B1 through B5, F1 through F3, and D1 and D2. There are ten fluid flow paths which must be simultaneously controlled. There are five switching modes designated DRAIN, FILL, FLUSH, RUN and BACKFLUSH. The table indicates whether a switch is open or closed.

#FIG. 1 illustrates the actual manual control knob 10 of the switch with the five switching positions being indicated with the same legends as in FIG. 8. In addition, the ten flow paths are shown as being provided by the ten flexible tubes 11A through 11J. The entire valve apparatus is surrounded by a metal box 12 shown in phantom which provides for electrical shielding from the remainder of the laboratory apparatus. This may be especially important in a platelet counter which uses the so-called Coulter counting principle, where the passage of particles through a narrow orifice creates an electrical pulse which is counted. As is apparent from the FIG. 1, each of the tubes 11A through 11J lie against and between rigid abutments rods 13 or 14 respectively, and the ends of levers 16A through 16J. Both the tubes and levers are paired and located opposite each other. The abutment rods 13 and 14 are held in their position by plates 17 and 18. In addition, the other end of the levers 16 are pivoted on similarly held rods 19 and 20, as best shown in FIG. 2.

#Now referring to FIG. 2, journaled for rotation in plates 17 and 18 is a shaft 10' which is rotated by the manual control knob 10. As shown in FIG. 7, shaft 10' carries on it for rotation five cams designated A through E.