| 摘要 |
607,433. Fluid-pressure servo motor-control systems. FROUDE, R. H. Feb. 4, 1946, No. 3466. [Class 135] [Also in Groups I and II] In liquid-treating apparatus the flow of liquid operates a pulsating member or a meter whereby electrical impulses in frequent succession are created to drive a stepby-step motor and thereby a drum, disc or series of discs constituting a switching mechanism to effect a cyclic function or cyclic functions at intervals governed by the quantity of liquid flowing through the apparatus. In watersoftening apparatus indicated by Figs. 1, 6 and 7, the pipe supplying the water is fitted with a venturi or similar differential pressure device 13 connected to a pulsator 14 through a solenoid-operated valve 16. Water entering the valve through an opening 17 is led by a connection 20 to one end of a diaphragm 15 and moves the diaphragm and a rod 29 whereby a stop 28 acts to tilt a mercury switch 25 causing the energization of a solenoid 23. The solenoid moves a piston 23, whereby the liquid is led to the other side of the diaphragm. Movement of the diaphragm, through stop 27 tilts the mercury switch so that a solenoid 24 is energized and the piston is moved back to its former position. The diaphragm continues to pulsate while the liquid is flowing, and the reciprocation of the piston acts through a pawl- and-ratchet 33 to rotate by steps a drum 34. The drum comprises coaxial discs each of which is partly formed of conducting material and is engaged by a spring finger connected to a source of electric current. The drum thus determines the energization of five solenoids which control five pilot valves, in turn controlling valves 1 to 9 and a byepass valve 78. The drum 34 instead of operating the valves through electric means may operate them by cams or like means. As an alternative to a differential pressure device to operate the pulsating diaphragm, a meter may be provided to operate a change-over or pilot valve to direct water pressure to alternate sides of the diaphragm, or the meter may make electrical contacts to give the impulses required to drive the step-by-step motor. |
