Mechanically actuated changeover valve for fixed-volume metering devices

摘要

A mechanically actuated changeover valve for a fixed-volume metering device for the metering of small volumes of liquid in analytical measurement technology. The long auxiliary times of the preparatory and concluding operations are to be restricted considerably and consequently the availability of the metering device is to be increased. The accelerated execution of said operations is made possible by a special design of the valve body in conjunction with a mechanical driving means designed for this. The changeover valve consists of a valve body made of cold-formed alloyed PTFE, a head piece and a connection piece. The valve body comprises the conical part and the sleeve. The connection piece possesses two conical bores, the cylinder two channels and the sleeve three perforations. The switching device consists of a switch body, a switch fork having two pivotable pawls and a handwheel, and the valve body and switching device are connected by means of a coupling device. The two conical bores form an angle of 150 DEG , the two channels the same angle, the first and second perforations an angle of 75 DEG and the second and third perforations an angle of 150 DEG .