Cam-driven fluid switching system - contains several two inlet, common outlet, switches and pump to draw fluid from lower inlet

摘要

There are a number of fluid switches, each of which connects its common outlet to one of two inlets. These are mounted in line and driven by individual cams mounted on a common shaft. Each switch can be removed from the assembly for maintenance with little disturbance to the others. Each switch consists of a cylinder containing a olunger rod (14) with three sealing rings (5,6 and 7), separated by two spacers (16). When the cam (21) drives the plunger to its highest position, the pump (10) draws fluid from the lower inlet (11), while the upper inlet is sealed off. When the plunger is in its lowest position, the pump draws fluid from the upper inlet while the lower inlet is sealed off.