Abstract: Means is associated with a carpet cleaner, or the like, having an adjustable nozzle height providing a multiple number of nozzle height positions, for automatically sensing the pile of the floor covering being cleaned and automatically indicating the appropriate nozzle height position for any specific floor covering upon which the cleaner is positioned by automatically measuring and indicating the pile height and density of such floor covering using a pile height and density sensor which is independent of the nozzle height position, that is, which gives a uniform reading for a specific floor covering pile height and density regardless of the nozzle height setting at the time of sensing.

Abstract: A vacuum cleaner detector that indicates when the hose is clogged and bleeds in cooling air to the vacuum chamber so as to prevent overheating of the motor blower. The indicator comprises an actuator valve and a relief valve. The actuator valve includes a pressure responsive member having filter bag compartment pressure applied to one side thereof and atmospheric pressure applied to the other side. When the absolute pressure within the filter bag chamber drops, the pressure responsive member is moved toward the low pressure side moving a plunger which opens a port when the pressure drops below that desired to allow filter bag chamber pressure to vent to the low pressure side of a pressure responsive member in the relief valve.

Abstract: A canister type vacuum cleaner having mechanism for controlling the negative pressure in the filter bag compartment by bleeding ambient air into the compartment. The mechanism includes a pivotable valve plate for overlaying an aperture in the filter bag compartment and an operator laterally slidable across the front of the cleaner and operatively connected by cam means to the valve. The valve plate is pivoted to selectively block the aperture by an amount determined by the position of the operator and the degree of negative pressure is indicated by the lateral position of the operator.

Abstract: A vacuum cleaner filter bag condition indicator that detects when the bag is substantially full and should be replaced. The indicator includes a pressure responsive member having internal filter bag pressure applied to a small area of one side thereof and filter bag compartment pressure applied to the entire other side. When the bag becomes substantially full the bag pressure increases and the increased pressure differential causes the pressure responsive member to move slightly to allow the filter bag pressure to act on the entire area of the one side. The pressure responsive means thereafter quickly moves toward the lower pressure side and forces an indicator button out the cleaner.