Treatment of small grassy areas, e.g., to apply fertilizer, insecticide, or selected herbicide to inhibit weeds, can be accomplished with the use of conventional sprayers or sprinklers. However, when relatively large expanses of lawn must be treated, e.g., around large public buildings, in parks, near airport runways, or on golf courses, considerations of efficiency, and economy require that the applied material be put in intimate contact with the grass and/or weeds quickly, evenly, and with minimum wastage of time or treatment material. Examples of previous attempts to solve this problem are discussed below.
U.S. Pat. No. 826,897, to Shely discusses an applicator in which a distributing tube is used to dispense a liquid from small openings therein. An interior sleeve of the tube is rotated to control the dispensing of the liquid.
U.S. Pat. No. 2,696,696, titled "Applicator for Weed-Killing Liquid", to Tigerman, discusses a manually-pushed applicator in which the liquid is gravity fed from a container to a distribution tube lying above and parallel to a roller contacting the underlying ground surface. The distribution tube is provided with three rows of outlets which are angularly equally spaced about the circumference of the tube.
U.S. Pat. No. 3,152,353, titled "Lawn Application for Fertilizer and the Like", to Cravener, discusses a generally similar device comprising a liquid container and an elongate distribution tube provided with a plurality of bottom orifices positioned over an underlying ground-contacting roller. The device is provided with a control valve between the liquid container and the distribution tube.
U.S. Pat. No. 3,255,929, titled "Herbicide Applicator", to de Haan, discusses a generally comparable device in which the roller is provided with an absorbent sleeve-like cover.
U.S. Pat. No. 3,408,149, titled "Liquid Applicator", to Lakes, discusses a device in which a chain-drive from a roller is utilized to pressurize a liquid container from which liquid is provided via a plurality of flexible connected tubes to a corresponding plurality of cooperating tubular elements spaced apart, above and parallel to the roller for flow of pressurized liquid downward to the roller. This device is also provided with a connector element for connection to a towing apparatus such as a riding lawn motor.
Finally, U.S. Pat. No. 3,560,102, titled "Liquid Herbicide Applicator", to Wetzel, discusses a manually-pushable applicator in which liquid from a container is gravity fed to an elongate distribution tube provided with a plurality of apertures and is covered with an absorbent sleeve and flap via which the liquid is distributed to an outer surface of an absorbent covering on the underlying roller.
As is obvious from the above-described known devices, provision of the liquid material via a plurality of orifices is known. However, the known devices do not apply the liquid material efficiently and evenly, especially over hilly terrain. In particular, the position of the distributing tube remains fixed relative to the frame of the device. If pushed or pulled along a slope such that the tube is tilted, the liquid will collect in the lower end of the tube resulting in uneven application.
Also, for fertilizers, herbicides, and insecticides which are produced and provided to users in powdered, granular or crystalline form and not directly as liquid compositions, it is likely that there will be partially-dissolved solid material during application which might clog the relatively small orifices through which the solution is intended to be dripped to the roller. Also, the liquid residue in the orificed distribution element may dry out and the solid/crystalline remnant may clog the distribution orifices. The result may be that the intended even distribution of the treatment material is not subsequently realized.
There has also become an awareness that liquid chemical agents are damaging to the environment when there is an application of excessive material resulting in run off into streams, ponds and rivers. Although the chemicals may be safe when properly applied, the uneven application of presently known devices causes the user to over apply the chemical agents in an attempt to compensate for any strips of grassy area left untreated. Consequently, the defects of the known prior art do not merely result in the poor application of the chemical agent; they also cause substantial damage to the environment when the total number of golf courses, lawns, etc. treated with the chemical agents are considered in the aggregate.
The present invention is intended to address the above-described problems with a simple, durable, inexpensive and easily maintained structure. The invention can be readily adapted to sizes ranging from simple manually-pushed structures to larger structures readily towable by riding lawn motors, tractors, or the like for treatment of very large areas of lawn.