초록 ▼

A control device for metering fluid flow from a remote location is shown in conjunction with an insecticide spraying apparatus. The spraying apparatus includes a compressed air source feeding pressurized air to a nozzle for mixing with a liquid and discharge to atmosphere. A metering pump feeds the

A control device for metering fluid flow from a remote location is shown in conjunction with an insecticide spraying apparatus. The spraying apparatus includes a compressed air source feeding pressurized air to a nozzle for mixing with a liquid and discharge to atmosphere. A metering pump feeds the liquid to the nozzle in response to a digitized input signal received from a remote control device. A digitized feedback signal including a number of pulses per unit time from the metering pump to the remote control device indicates the rate of flow of the liquid through the metering pump. The remote control device compares the digitized feedback signal with a control voltage to generate the digitized input signal which is a pulse-width modulated signal, which digitized input signal maintains the flow rate of the liquid. A pressure switch connected to the nozzle insures a predetermined pressure therein before the metering pump will begin feeding liquid to the nozzle.

대표청구항 ▼

Spraying apparatus for spraying accurately controlled amounts of liquid into the atmosphere without direct measurement of the liquid flow, said apparatus comprising a source of said liquid, a nozzle through which said liquid is sprayed, conduit means extending between said source and said nozzle and

Spraying apparatus for spraying accurately controlled amounts of liquid into the atmosphere without direct measurement of the liquid flow, said apparatus comprising a source of said liquid, a nozzle through which said liquid is sprayed, conduit means extending between said source and said nozzle and liquid pumping means interposed along said conduit means, said liquid pumping means comprising a metering pump of the positive displacement type, the liquid flow through which corresponds directly to its operational speed, a pump shaft connected to said pump, remote sensing means connected to said pump shaft to detect the pump shaft speed, said remote sensing means comprising an electrical signal generator arranged to produce electrical flow rate signals in direct relationship to the rotational speed of said pump shaft and further comprising a remote display for remotely displaying said electrical flow rate signals, a control generator arranged to be adjusted at said remote display and settable to produce control signals and electrical circuit means comprising a differential detection circuit connected to receive said control signals and said flow rate signals and to produce an adjustment signal corresponding to the difference between said control and flow rate signals and means for changing pump speed in accordance with said adjustment signal.