Abstract: A filter device for ambient air filtration has a blower housing with air inlet and air outlet. A device for generating an air flow is arranged in the blower housing and generates an air flow in operation from air inlet to air outlet. A flexible air conducting hose is provided with a first open end connected to the air outlet of the blower housing and with a second closed end. The flexible air conducting hose has openings arranged between first open end and second closed end. Filter elements are arranged in the openings, respectively. The filter elements separate a raw side inside the air conducting hose from a clean side downstream of the filter element. The air conducting hose is inflated in operation of the device by the air flow. The flexible air conducting hose has a reduced air permeability compared to the air permeability of the filter elements.

Abstract: A double-diaphragm pump is designed to be molded almost entirely out of plastic and is provided with totally externally-accessible and serviceable check valves which do not require any significant disassembly of the pump itself. The pump is also fitted with a diaphragm which is formed from a uniform thickness of material and which have convolutions which are equally disposed on either side of the angle of elevation of the unstressed diaphragm. The pump is designed for mounting on top of a barrel or drum and has a set of radiused feet so as to fit snugly against the rim in an inlet pipe which fits into a bung plug having an eccentric opening such that the opening grips the inlet pipe and the plug may be rotated so as to snugly position the pump against the rim of the drum. The air valve to the pump is provided with U-cup seals in the housing.