Land vehicles – Wheeled – Running gear
Reexamination Certificate
1998-07-14
2002-09-24
Dickson, Paul N. (Department: 3611)
Land vehicles
Wheeled
Running gear
C280S678000, C280S781000, C180S900000, C180S068400
Reexamination Certificate
active
06454294
ABSTRACT:
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to vehicles, and in particular to high clearance vehicles for general agricultural use.
2) Related Art
High clearance agricultural vehicles have been known for years. They are particularly useful in spraying row crops. In this instance, these are typically designed for use with maturing corn of four or five feet in height and in order to avoid damage to the crop, the vehicles have a general clearance at least equal to the height of the rows of crops, (hence the vehicles are relatively tall pieces of equipment). These vehicles generally have at least two drive wheels the width of which allows the vehicle to pass between two different crop rows. The vehicles are also equipped with a boom which extends outwardly from both sides of the vehicle to spray relatively large crop areas at a time.
In one manner of application, sprays are applied to the crops during the tilling stage when the crops are quite small and a conventional ground-type crop sprayer could traverse the field without causing damage to the small plants. However, conventional ground supported crop sprayers are usually not suitable during the latter stages of growth. For example, during the stem extension stage, the likelihood of damage to the standing crops increases if the spray is applied by a ground traversing conventional crop sprayer.
Conventional crop sprayers are even more unsuitable for applying agricultural sprays during the heading and ripening stage of the crop. However, in order to obtain a good yield, it is often necessary to apply spray, for example, a fungicide, during the these stages especially to crops such as, wheat, barley, and the like. Spraying at these latter stages of growth has been typically done by aerial spraying in order to avoid damage to the standing crop. The effectiveness of aerial spraying is dependent in large part upon the weather conditions, and even then, the application of the spray is not as effective as ground spraying if damage to the standing crop can be avoided. Further, the spray must be concentrated when applied by crop aerial dusting because of the limitations of the capacity of the aerial sprayer.
Because spray vehicles operate over rough ground and in tall mature crops, various devices are used to help cushion the vehicle, operator, and boom from the effects of these rough surfaces. Most of these devices suffer from one or more disadvantages such as limited cushioning or bulkiness leading to interference with spraying the crop. A cushioned wheel arrangement, such as the front wheel suspension shown in U.S. Pat. No. 5,066,030, is available for relatively small sprayers with a single steerable wheel. However, such a suspension is not suitable for most larger sprayers or sprayers having two or more steerable wheels. Some available self-propelled sprayers have strut suspensions such as the one disclosed in U.S. Pat. No. 5,597,172. Strut shaft type suspensions may not have the ability to provide all of the traction necessary to move freely about rough terrain. Furthermore, the strut shafts may bend under rough terrain conditions thus making the vehicle less durable.
Sprayer suspensions with strut shafts may also include steel suspension springs immersed in oil. However, these often leak, and require supports with relatively large diameters both above and below the axle which interfere with the crops. Therefore, providing adequate cushioning without adversely affecting the crops continues to be a problem. Further, commercial systems with spring suspension systems have added cab roll on sloping terrain which results from compression of the springs.
U.S. Pat. No. 5,353,988 shows another suspension system. One of the drawbacks of this system is that the swing arms pivot point is high (for ground clearance) and the wheels are low. This configuration can cause problems when the vehicle hits a bump because the wheels move out as much as they do up. Thus, every bump the vehicle hits tends to shove the wheel into the crop which can damage the crop. Moreover, as the vehicle's load gets heavier or lighter, it changes its wheel track, so that when it's fully loaded it may be running over the outside rows and when it is empty it may be running over the inside rows.
Because row spacings in row crop situations can vary from field to field, the wheel track of the spray vehicle must be adjusted accordingly. Linkage adjustments may be time-consuming and inconvenient. For example, when spraying solid seeded crops such as wheat or barley, sprayers must drive directly over the plants which may cause damage. An adjustable linkage for a sprayer is shown in U.S. Pat. No. 5,464,243. Other vehicles can manually widen one set of wheels independent from the other to reduce the potentially damaging track of their wheel configurations. However, manually adjusting the wheel configurations can take a considerable amount of time and thus again reduce the vehicle's productivity.
Steering arrangements for cushioned sprayer wheel assemblies include those with steering arms at the tops of the strut shafts. Such top mounted arm arrangements often have an undesired movement of the steerable wheels over rough ground surfaces, referred to as bump steering, as the steering arms move up and down with the strut shafts.
Conventional vehicle tanks may contain one tank for product, a separate tank for rinse water, and another tank for foam marker fluid. All of these tanks increase the surface area of the vehicle which makes the vehicle more difficult to clean. Further, this multitude of tanks adds unwanted bulk and takes up space on the vehicle which could be put to better use. Connecting these various tanks to each other, to the boom, and to the vehicle involves a complex connection of hoses, circuitry, and clamping devices. These aspects make it difficult for the operator to move around the tanks when it is necessary to plumb them and clean them.
Some booms contain little or no suspension. These booms that do contain suspension may have tilt cylinders out at the ends of the booms to adjust height and provide some suspension or they may have some other elastic member to take the shock out during travel over rough terrain. However, as a boom increases in length, for example, fifty feet or more, the travel at the ends of the boom may become more violent when moving over rough terrain which may cause the boom to hit the ground or, even worse, snap. Moreover, a violently bouncing boom that is uncontrolled may translate this energy to the vehicle making it increasingly less stable and more difficult to control (which, in turn, can effect the precise application of spray to the crops).
Maintaining good visibility from the cab of the spray vehicle to the crops, the boom and nozzles and maintaining a direct line of sight from the cab to the wheels is also important but has been problematic in the past. For example, some commercial systems have the boom and the nozzles mounted behind the cab. This forces the operator to constantly turn and bend to maintain visibility.
Some high clearance vehicles rely on conventional cooling systems to suck air past the engine and the hydraulic oil cooler. These systems may become clogged with dust and debris when the high clearance vehicle is operating in early spring or late fall field environments. When air flow is effected, engine and drive system efficiency is reduced. The possibility of overheating increases also. These problems can lead to decreased fuel efficiency, increased down time, and even worse, permanent damage to the engine and/or the hydraulic oil system.
Most commercial systems contain thrust washers within their steering systems. Thrust washers bear the weight of the load. For example, when the wheels are turned, the wheels pivot and the load bears down on the thrust washers which then carry this thrust force until the vehicle has completed its change in direction. When servicing these thrust washers, some systems require that the operator remove all hoses and connections to the
Bittner Roy A.
Jennings Richard E.
Ridenour Marcus J.
Dickson Paul N.
Lum L.
Miller St. Nazianz
Whyte Hirschboeck Dudek SC
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