Floor coverings such as carpets and rugs are prone to marks and stains. Floor coverings can be cleaned in a number of ways, which can be classified as ‘wet’ or ‘dry’ cleaning methods. Wet cleaning methods such as washing or shampooing the floor covering have the disadvantage that they can cause shrinkage of the floor covering. Dry cleaning generally involves depositing a powdered composition onto the floor covering which can readily absorb soil and contaminants from the floor covering. The powder is worked into the floor covering with the aid of a brush. Finally the dirty powder can then be removed from the floor covering by a vacuum cleaner. While such compositions are called ‘dry’, in that they flow as a powder at room temperature, they usually contain a quantity of liquid such as water or organic solvents.
The cleaning powder needs to be dispensed on to the floor covering. U.S. Pat. No. 4,268,935 and U.S. Pat. No. 5,101,532 describe powder-dispensing machines for use in cleaning carpets. In U.S. Pat. No. 5,101,532, a dispensing hopper is integrally formed as part of the machine for storing and dispensing dry-cleaning powder. At the front, lower part of the hopper there is a jaw which is formed by a lower flap which is hingedly fixed to the hopper. In use, the flap is oscillated about a mean gap width of around 4 mm so as to dispense powder onto the floor surface. The position of the lower flap is controlled by a user-operated control which moves the flap between one of two fixed positions: a dispense position, in which the flap is set to the 4 mm gap, and a grooming and vacuuming position in which the flap seals the hopper to prevent any powder escaping from the hopper. In use, the machine dispenses powder onto the floor surface at a controlled rate.
In the dispenser of U.S. Pat. No. 4,268,935 a powder dispenser is attachable to a vacuum cleaner. The dispenser has a hopper within which a metering drum is rotatably mounted to regulate the flow of powder from the hopper. A closure member is mounted within the hopper, downstream of the metering drum and just upstream of the discharge outlet. The closure member is manually operable between an open position in which powder may fall from the metering drum to the discharge outlet and a closed position in which the outlet is blocked.
A removable dispenser is convenient in that it only needs to be mounted on the cleaner when it is required. During normal cleaning the dispenser can be removed and stored without cluttering the cleaner. However, the use of a removable dispenser can cause some handling problems for inexperienced users. A user may not require all of the powder that they have poured into the dispenser with the result that the dispenser may still be partially filled with powder when it needs to be removed from the cleaner. Without careful handling there is a likelihood that powder will be spilled on to the floor surface. This results in dissatisfaction for a user.
USPTO Backgrounds
USPTO Backgrounds