1. Field of the Present Invention
The present invention relates generally to systems that convey bulk commodities from primary locations in carts and wagons to secondary locations such as barns, silos, trailers, and train cars. More particularly, this invention relates to an improved, two-piece folding auger system for grain carts, and to grain carts equipped with auger assemblies.
2. History of Related Art
Numerous agricultural implements including combines, harvesters, and grain carts are equipped with internal grain storage hoppers. Grain harvested from the field may be conveyed for short term storage into mobile hoppers such as grain carts for subsequent towing to larger storage bins or silos, or for transport to truck or railroad yards. For example, grain carts are commonly deployed during the process known as combining, where they are towed into a convenient, receptive position by a tractor proximate a combine to periodically receive the combine's contents for short term storage and later transfer.
Fluids and grain are moved by commonly understood displacement means along a continuous spiral fin helically disposed around rotating shafts. The continuous fin is sometimes called “flighting,” the apparatus is typically called an “auger,” and such displacement is generally called “augering.” As recognized by those skilled in the art, various powered augers with spiral flighting are employed to move grain from containers such as carts, wagons, trailers, truck beds, hoppers, and silos. Conventional augers may be powered by hydraulics, pneumatics, or a power-take-off (PTO), the standard means of gearing by which power from a tractor is externally transferred to various farm implements through commonly understood couplings.
Retractable auger systems typically include two or more foldable sections that are un-folded for use and folded for transport or storage. These auger systems are typically made of a fixed lower section inside of or adjacent to a hopper, and a moveable upper section that is un-folded into an operative position coaxially aligned with the lower section. When properly deployed, the upper auger section delivers grain to a desired receptacle. When retracted, the upper auger section nests against the cart body and assumes a safe, out-of-the-way orientation that facilitates cart movement.
Typically, both auger sections include internal drive shafts that have spiraled flighting built into or attached to their outer diameters. When configured for operation (i.e., in the un-folded, operative position), the auger sections are aligned substantially coaxially, and their internal drive shafts axially mate. The power source that typically drives the lower auger section is thus indirectly coupled to the upper auger section. Various couplers that are well known in the art mate the two sections. For example, the auger drive shafts may be connected with a universal joint or with a coupling assembly that provides a “quick connect.” Such a connection for quickly mating the upper and lower auger sections may include an aligning pilot shaft made a part of the lower section drive shaft and centered within an annular bearing. A plurality of radial drive teeth projecting from an annular surface on the lower auger drive shaft engage similarly arrayed teeth on the upper section drive shaft. The coupler teeth are meshed when the auger segments are in the un-folded, operative position, and the drive shafts are substantially aligned.
Grain cart augers are subjected to appreciable stresses. The load borne by the flighting during high volume operation exerts appreciable lateral and torsional stress on the drive apparatus, flighting, drive shafts, and the shaft control bearings. Stresses are dynamically imposed on the structure in a variety of changing directions. Occasionally, particularly at start-up, a load jars the apparatus and subjects the flighting to forces that tend to unbalance or misalign the multiple auger sections. Improper auger section alignment can easily result in bearing failure and other damage to the apparatus.
Prior art grain cart auger mechanisms suffer from maintenance and reliability problems. Mechanisms must be rugged in order to withstand the impacts and the rain, dust, and temperature changes inherent in farm use. Mechanisms that have moving parts are particularly vulnerable to harsh operating conditions. And mechanisms that are built in sections for conversion from an un-folded, operating profile to a folded, transport profile are also vulnerable. Accordingly, it Would be beneficial to have an auger assembly that can withstand harsh conditions and be easy to maintain and have sections that easily align when the auger assembly is in the un-folded, operative position.