BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains generally to fluid spraying, and more particularly to a retractable spray shield for agricultural use that deflects the flow from at least one spray nozzle.

2. Description of the Related Art

Modern agriculture has for most of a century advanced in productivity more than many other industries. Most consumers are generally unaware of these significant advances. However, the consumer has benefitted greatly, in particular because of the lower-than-inflation price changes in many agricultural products through this long time period. Most agricultural operations today incorporate extremely technically advanced machinery, seed, and chemicals that allow one person to do the work that even only a few decades ago required many. One particularly common and exemplary machine is the tractor, which has increased greatly in size, power, and in the many diverse attachments that are used to facilitate operations.

The commercial production of many agricultural crops involves the spraying of one or more chemicals such as herbicides, fertilizers, insecticides, or fungicides. The products being sprayed may be used to improve the health of the desired crop, or to eliminate or reduce detrimental interaction with diseases, pests, and competing weeds. To reduce the time required to apply these products to the crop, very large sprayers have been produced that carry a large liquid tank, a pump having a fluid inlet coupled into the liquid tank, at least one boom arm typically extending generally transversely to the direction of travel, and a plurality of spray nozzles supported by the boom and coupled through liquid supply lines to the pump outlet. The sprayer may be an attachment to a tractor, or an entirely separate machine. A person operating the sprayer will typically be able to control the pump to turn on or off the spray, and in many cases to control the pump pressure, which in turn controls the rate of delivery of the liquid to the crop. Through the use of this equipment, spraying of liquid chemicals is both time efficient and controllable to the needs of a particular crop, field, or even location within a field. As a result, a relatively precise amount of chemical may be applied rapidly to a large area.

As may be appreciated, the quantity of spray delivered to a crop can be relatively precisely controlled beneath the boom. When multiple passes are made across a field, for each pass the end of the boom arm can be located offset by the right amount from the previous pass to provide just the right amount of overlap in the spray coming out beyond the end of the boom. However, the sprayer will only pass over the edges of the field once. Consequently, adjacent to the edges of the field a tractor operator will normally make sure the last row of crop will be under the last sprayers, to ensure adequate liquid is delivered to this final row. Unfortunately, this also means that spray will be delivered beyond the last row of crop, typically on to adjacent plants. As may be appreciated, these adjacent plants are not a part of the desired crop, and so may include an adjacent field containing a different crop, a grass covered ditch, a neighboring property under different ownership, or undesirable weeds.

In the case of the application of an herbicide with the overspray falling onto a different crop, a grass covered ditch, or a neighboring property, those adjacent plants undesirably may be killed or seriously harmed by the spray. In the case of undesirable weeds, and since these weeds are not immediately under the boom and are instead being treated with overspray, the concentration of application is generally less than that intended for application to the field. As a result, the overspray may not be sufficient to kill the weeds, and so may instead lead to the development of weeds resistant to the spray. These weeds may then encroach upon the desired crop, hurting the yield or value of the harvested crop. Similar deficiencies may be encountered in the case of insecticides and fungicides, such as where adjacent insects may develop insecticide resistance. In the case of a fertilizer overspray, adjacent weeds may be undesirably strengthened and stimulated. Consequently, and for a variety of reasons, it is desirable to reduce or eliminate overspray adjacent to the edges of a field, while not interfering with the spray within the middle of the field.

To reduce the overspray, artisans have designed various shields that are designed to enclose a single row of crop. The spray nozzles are mounted to spray into the interior of the shield, and thereby avoid spray into the between row spaces and to prevent overspray. Exemplary U.S. patents and published applications, the teachings which are incorporated herein by reference, include: U.S. Pat. No. 3,445,961 by Elsworth, entitled “Agriculture spraying machines”, which illustrates a pair of plastic guides that gently squeeze the plants together, and a liquid that is sprayed interior of the guides into the squeezed plants; and U.S. Pat. No. 4,947,581 by Claussen et al, entitled “Spray shield assembly”, which illustrates a set of shields in the general shape of an upside-down “U” channel open on both ends but closed on the top and sides. For some applications, such as that of a fertilizer, either of these apparatus will reduce or avoid undesirable overspray on to other plants besides the agricultural crop. However, for other liquid applications, particularly herbicide applications, the entire field needs to be sprayed, making these shields useless for such applications. Furthermore, these shields must be set for a particular row spacing, meaning they will typically require resetting for each different species of crop. The variable height of different species and different stages of maturity are also challenging. Finally, there are many times when a spray will be most effectively sprayed by nozzles spraying at an angle closer to parallel to the ground than perpendicular thereto. Spray from relatively more horizontally pointing nozzles that misses the immediately adjacent row of crop, such as when the spray nozzle is pointing between sequential plants in a row, may still end up being applied to plants in a nearby row. In the case of a shield such as illustrated by either Elsworth or Claussen et al, any spray that misses the plant will instead be applied only to the shield, and from there will drip onto the soil without ever contacting the plant.

Additional U.S. patents illustrate fixed shields for crops, the relevant teachings and contents which are incorporated herein by reference, including: U.S. Pat. No. 2,589,020 by North, Jr, entitled “Spraying device”; U.S. Pat. No. 4,274,589 by Jones, entitled “Spraying apparatus employing a skirt structure”; U.S. Pat. No. 4,986,473 by Semple et al, entitled “Crop sprayer shield”; U.S. Pat. No. 5,139,200 by Greimann et al, entitled “Shield for agricultural sprayer”; U.S. Pat. No. 7,063,273 by Hahn et al, entitled “Spray delivery system”; and U.S. Pat. No. 8,573,510 by Bisson et al, entitled “Drift shroud system for spray booms of turf sprayer”. Unfortunately, these prior art shields are quite large and designed to operate close to the ground, and so are susceptible to damaging interference with rocks, roots, mounds, and other obstacles in the ground. As with the Elsworth or Claussen et al shields, these shields are fixed in geometry. This means that even in the middle of the field, the farthest transverse edges (the left and right extremes) of the shields will undesirably block spray from reaching plants, and will instead drip the spray onto the earth. Any fixed shields that do not block the spray on the transverse edges will likewise not prevent the undesirable overspray discussed herein above.

Additional patents of varying relevance, the relevant teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,565,341 by Burroughs, entitled “Spraying apparatus”; U.S. Pat. No. 4,124,221 by Goings, entitled “Spray guard for vehicles”; U.S. Pat. No. 4,927,080 by Alsing, entitled “Field spraying device”; U.S. Pat. No. 5,062,572 by Reiter et al, entitled “Spray shield”; U.S. Pat. No. 5,549,457 by Flores et al, entitled “Pavement sprayer having movable spray guard”; U.S. Pat. No. 8,066,304 by Ulgen, entitled “Retractable mud flap for vehicles”; and Des U.S. Pat. No. 702,124 by Harrower et al, entitled “Rotatable spray shield device”.

In addition to the foregoing patents, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.

As may be apparent, in spite of the enormous advancements in agriculture and substantial research and development that has been conducted, there still remains a need for a spray shield that will permit efficient spraying in the middle of a field while also selectively blocking overspray at the field edges.

SUMMARY OF THE INVENTION

In a first manifestation, the invention is a selectively deployable spray shield for agricultural use. A spray barrier has a generally triangular and flaccid liquid barrier film, a pair of framing legs, each of the pair of framing legs coupled to an opposed edge of the liquid barrier film, a hinge plate, a first pintle coupling a first one of the pair of framing legs to the hinge plate, a second pintle coupling a second one of the pair of framing legs to the hinge plate, a spring guide post intermediate between the first and second pintles, and a tension spring wrapped about the spring guide post configured to operatively stretch the pair of framing legs apart from each other and thereby expand the spray shield toward a planar, generally triangular geometry. A clam-shell storage tube defines a path for the hinge plate to reciprocate along, and is configured to receive and conceal the spray shield on an interior when the clam-shell storage tube is closed. A deployment and concealment drive has a motor, a drive shaft, and a quadrilateral linkage including a rotating arm and a pushing arm coupled with the drive shaft. The drive shaft rotates the pushing arm relative to the clam-shell storage tube and thereby also rotates the rotating arm relative to the clam-shell storage tube between a first concealed position having the rotating and pushing arms parallel and adjacent to the clam-shell storage tube and the spray barrier concealed within said clam-shell storage tube to a second deployed position having the pushing arm parallel and adjacent to the clam-shell storage tube and the spray barrier deployed outside the clam-shell storage tube.

In a second manifestation, the invention is, in combination, an agricultural spray machine, an agricultural spray boom, and a retractable spray shield for agricultural use. The agricultural spray machine has an operator cab; an electrical system; a drive train; a liquid tank; and a pump receiving a liquid held within the liquid tank. The agricultural spray boom has a boom arm extending transverse to a forward direction of travel of the agricultural spray machine; and at least one spray nozzle suspended from the boom arm and in fluid communication with the pump. The retractable spray shield for agricultural use has a hinge plate; a liquid barrier film extending from the hinge plate; a clam-shell storage tube defining a path for the hinge plate to reciprocate along, and adapted to receive and conceal the spray shield on an interior when the clam-shell storage tube is closed; a deployment and concealment drive having a motor, a drive shaft, and a quadrilateral linkage including a rotating arm and a pushing arm coupled with the drive shaft, the drive shaft rotating the pushing arm relative to the clam-shell storage tube and thereby also rotating the rotating arm relative to the clam-shell storage tube between a first concealed position having the rotating and pushing arms parallel and adjacent to the clam-shell storage tube to a second deployed position having the pushing arm parallel and adjacent to the clam-shell storage tube; and a boom arm coupler adapted to couple the retractable spray shield to the agricultural spray boom and simultaneously locate the liquid barrier film in the second deployed position adjacent to and in a spray pattern of the at least one spray nozzle.

Objects of the Invention

Exemplary embodiments of the present invention solve inadequacies of the prior art by providing a retractable spray shield for agricultural use. The retractable spray shield has a liquid barrier film; a storage tube; a deployment and concealment drive that in one direction deploys the liquid barrier film from the storage tube and in a second direction opposed to the first direction conceals the liquid barrier film within the storage tube; and a pivotal quick release support and boom arm coupling.

The present invention and the preferred and alternative embodiments have been developed with a number of objectives in mind. While not all of these objectives are found in every embodiment, these objectives nevertheless provide a sense of the general intent and the many possible benefits that are available from embodiments of the present invention.

A first object of the invention is to provide an apparatus that may be deployed to reduce or eliminate overspray adjacent to the edges of a field, and which may be concealed so as to not interfere with spray within the middle of the field. A second object of the invention is to enable the apparatus to be deployed or concealed from within the cab of a spray vehicle, without necessitating the operator to disembark from the cab. Another object of the present invention is to facilitate the spraying of a variety of fields, without the need for mechanical adjustment to a particular species, or plant height and maturity. A further object of the invention is to provide apparatus that is effective with a spray emanating generally at an angle closer to parallel to the ground than perpendicular thereto. Yet another object of the present invention is to achieve the foregoing objectives with an apparatus that is easily fabricated and which may be easily installed upon both new and existing spray boom arms.

