Protective device for work in polluted environment

Claim 1

A device for protecting an operator within the cab of a mobile plant working in a polluted environment comprising an air treatment unit adapted to be incorporated into the cab accommodating said operator, said air treatment unit comprising an air inlet port, at least one coarse filter element, a fine filter element and a chemical filter element, the filter elements being in fluid communication with the inlet port, and a motor driven fan having a suction and a discharge, the suction being connected to receive filtered air from the filter elements, the fan discharge being adapted to discharge the filtered air into the cab; an air recycling means between the cab and the air treatment unit, the recycling means comprising a recycling opening inter-communicating the cab and the air treatment unit, a trap intermediate the fine filter and the chemical filter, the trap being movable from an open position to permit recycled air from the cab to bypass the fine filter but not the chemical filter prior to entering the fan and a closed position wherein recycled air is prevented from passage; a pressure monitoring device affixed to the cab to monitor the air pressure differential inside of and outside of the cab; a toxicity monitoring system to monitor the toxicity of air inside of and outside of the cab, the toxicity monitoring system comprising a first toxicity sensor within the cab and a second toxicity sensor mounted exteriorly of the cab; and electrical circuit means operatively interconnecting the air recycling means, the pressure monitoring device and the toxicity monitoring system.

Claim 2

A device for protecting an operator within the cab of a mobile plant working in a polluted environment comprising an air treatment unit adapted to be incorporated into the cab accommodating said operator, said air treatment unit comprising an air inlet port, at least one coarse filter element, a fine filter element and a chemical filter element, the filter elements being in fluid communication with the inlet port, and a motor driven fan having a suction and a discharge, the suction being connected to receive filtered air from the filter elements, the fan discharge being adapted to discharge the filtered air into the cab; an air recycling means between the cab and the air treatment unit, the recycling means comprising a recycling opening inter-communicating the cab and the air treatment unit, a trap intermediate the fine filter and the chemical filter, the trap being movable from an open position to permit recycled air from the cab to bypass the fine filter but not the chemical filter prior to entering the fan and a closed position wherein recycled air is prevented from passage; a pressure monitoring device affixed to the cab to monitor the air pressure differential inside of and outside of the cab; a toxicity monitoring system to monitor the toxicity of air inside of and outside of the cab, the toxicity monitoring system comprising a first toxicity sensor within the cab and a second toxicity sensor mounted exteriorly of the cab; and electrical circuit means operatively interconnecting the air recycling means, the pressure monitoring device and the toxicity monitoring system.

Claim 9

A device for protecting the operator of mobile plant working in a polluted environment, comprising an air treatment unit adapted to be fitted or incorporated into a roof of a cab accommodating said operator, said air treatment unit containing an inlet port, at least one coarse filter element, a fine filter element, a chemical filter element and outlet port including a motor driven fan, a pressure monitoring device including a sensor exteriorily of the cab and a second sensor interior of the cab, a toxicity monitoring system comprising one semiconductor sensor within the cab, a second semiconductor sensor adapted to be disposed externally of said cab and a third semiconductor sensor adapted to be disposed behind the air treatment unit, and a display panel disposed inside the cab connected to said semiconductor sensors.

Claim 10

A device for protecting the operator of mobile plant working in a polluted environment, comprising an air treatment unit adapted to be fitted or incorporated into a roof of a cab accommodating said operator, said air treatment unit containing an inlet port, at least one coarse filter element, a fine filter element, a chemical filter element and outlet port including a motor driven fan, a pressure monitoring device including a sensor exteriorily of the cab and a second sensor interior of the cab, a toxicity monitoring system comprising one semiconductor sensor within the cab, a second semiconductor sensor adapted to be disposed externally of said cab and a third semiconductor sensor adapted to be disposed behind the air treatment unit, and a display panel disposed inside the cab connected to said semiconductor sensors.