摘要 |
The invention resides in a compound valve having utility in a sample injector for a liquid chromatograph. The valve has a pair of rotary spool valves (52, 54), each valve has a shaft (60) with an axial bore (64) in one end and a radial bore (66) communicating with the axial bore. A valve seal (70) surrounds the shaft. A pair of radial passageways (77, 78) in the seal are aligned diametrically and lie in a common plane with the radial bore (66) in the valve shaft. A pinion (62) is fixed to each shaft and a common driving gear (68) engages each pinion to rotate both shafts simultaneously through 180 DEG to place the radial bores in the shafts in communication selectively with either radial passageway in the valve seals.
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