Clean windshields are important for safety reasons and it has long been known that virtually all vehicles such as automobiles, trucks and the like have been equipped with what are known as windshield washing devices. These windshield washers include a fluid reservoir, a pump, hoses for transferring the washer fluid, and nozzles for spraying the washer fluid on to the windshield. The purpose of these devices is, of course, to provide water, washing fluids including detergents or other additives, and the like to the windshield in order to clean the windshield.
In many if not all systems, the washer equipment is designed to operate in conjunction with the windshield wiper system, so that the fluid can be spread over the windshield and loosen and remove dirt, ice, dust or other contaminants that have reduced visibility. In colder climates, where temperatures drop below freezing, it is necessary to add antifreeze to the washer fluid to prevent the fluid from freezing in the reservoir or connecting hoses. At those times, it is often necessary to wait until the defroster has melted or otherwise loosened ice or snow that may have accumulated on the windshield from weather conditions. Sometimes, the windshield wiper system becomes frozen from melted and re frozen ice or snow and it is necessary to clean the windshield and free the wiper system by hand. Other times the combination of cold, dirt, frozen wiper blade systems all cooperate to smear and otherwise obscure the windshield, requiring a special effort to restore safe and adequate visibility. At best this is a cold and unpleasant task. At worst it exposes the operator to inclement weather and other dangers of the environment. For weak, elderly and frail persons, this becomes more than an inconvenience.
One system has been proposed to remedy the above described difficulties. This system is described in U.S. Pat. No. 4,832,262 to Robertson. Robertson describes a heat exchange member which is contoured to fit along one side of an exhaust pipe of a vehicle. Hoses are provided to circulate water or washer fluids from the reservoir to the heat exchanger to the pump and finally to the windshield. Robertson discloses a system which requires engine heat, thus being less than effective when a cold vehicle has just been started. This prior art system also requires that the fluid be pumped to the heat exchanger and then to the windshield washer nozzles, so that as the engine continues to heat, fluid or vapor from the fluid continues to flow even after the washer device has been turned off. Once the automobile or truck has achieved a hot, operating condition it has been found that the Robertson system actually reduces visibility by continuing to discharge a fine mist that is not wet enough to be cleaned quickly by the windshield wipers. This mist dries quickly, leaving a film that continues to reduce visibility rather than clean the windshield.
Accordingly, it is an object of the present invention to provide a windshield washer system that can be modified to operate in cold and unpleasant weather without regard for engine temperature or operation.
Another object of this invention is to provide a device which is capable of providing warm or even hot washer fluid to a windshield washer system without waiting for the vehicle engine to generate heat.
Yet another object of the present invention is to provide a device capable of providing warm or hot washer fluid without continuing to contaminate the windshield with unwanted spray or mist after the system has been deactivated.
Other objects will appear hereinafter.