Apparatus and method for washing exterior building surfaces

Abstract

A system for washing building windows and other exterior surfaces. The system uses substantially pure water as the washing medium, and uses a novel cable restraint system for restraining an automatic cleaning device against the building surface.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates generally to a system for washing windows and other exterior surfaces of buildings. In particular, it relates to a window washing system which uses substantially pure water to clean such building surfaces, and which uses a novel cable restraint system for restraining an automatic cleaning device against the building surface.2. Description of the Related ArtBuilding structures, particularly tall urban buildings, are typically washed manually. A scaffolding structure is usually suspended from the top of the building to be washed. The scaffolding can be raised or lowered so that a person standing on the scaffolding can wash the windows and exterior surfaces of the building by hand. After a vertical section of the building is washed, the scaffolding is repositioned laterally so that the next adjacent vertical section of the building may be cleaned. This procedure may be repeated until the entire building has been...

AI Technical Summary

Benefits of technology

By using substantially pure water as the rinsing medium, the water need not be removed from the surface (i.e. the surface need not be dried) in order to avoid spotting of the surface after washing. Thus, this embodiment of the invention may eliminate the need to include a blower or other mechanical means for removing the water from the wash surface. This provides a substantial advantage in reducing the cost and weight of conventional washing units.

Generally, it is preferable to maintain the wash water substantially within the peripheral boundaries of the washing unit during washing operation. For this purpose, the scrubbing means of the washing unit may comprise a rotatably mounted brush, having bristles oriented in a helical pattern with right and left pitch, such that upon rotating the brush in use in a downward direction across the building surface, the rinse water will be directed toward the center of the washing unit. The device may also include sealing strips, strip brushes, or the like around the periphery of the inner side of the device to keep water from escaping outside its boundaries.

In a preferred embodiment, the cleaning device includes a pulley mounted thereon for the restraining cable to pass over, facilitating movement of the cleaning device across the building surface to be cleaned. A compression spring preferably separates the pulley and cleaning device, so that the pulley can move laterally towards and away from the cleaning device as the cleaning device traverses the building surface to be cleaned. As should be understood, the spring will be compressed to its greatest extent (and the pulley will be closest to the device) when the device is nearest the points at which the restraining cable is attached to the building, i.e. at the upper and lower points of the device's travel. As the device descends from its uppermost point to the middle of the building, the force exerted by the restraining cable on the spring will generally decrease, and thus the pulley will move away from the device. Then, from the middle of the building to the bottom of the descent, the force exerted by the restraining cable on the spring will increase, and the restraining cable will thus push the pulley towards the device.

Problems solved by technology

As should be apparent, the purer the rinse water, the better it will serve as the rinsing medium, but cost considerations may dictate the level of water purity desired.

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