Conveyors: power-driven – Conveying apparatus entirely supported by mobile ground... – Conveyor shiftably mounted on vehicle
Reexamination Certificate
2001-06-29
2002-10-29
Bidwell, James R. (Department: 3651)
Conveyors: power-driven
Conveying apparatus entirely supported by mobile ground...
Conveyor shiftably mounted on vehicle
C198S300000, C198S813000, C073S861730
Reexamination Certificate
active
06471032
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to an elevator for bulk material, and related apparatuses, in particular but not exclusively for use in harvesting machines, grain silos and hoppers.
2. Background of Prior Art
An example of the mass flow or bulk flow of so-called “bulk material” is the flow of grain to the grain tank in a combine harvester. It is known to provide a flow meter that operates by measuring forces of this flow on a sensor surface. Such flow meters may also be employed in hoppers, silos, harvesting and cutting machinery other than combine harvesters, conveying machinery and various kinds of manufacturing and medical apparatuses.
Bulk flow may also embrace, e.g. the flow of bulk grain and chemicals in transport vehicles (such as tankers, ships and railway tanker wagons); the flow of e.g. powders, and materials of larger particle size such as fruit, vegetables, coal, minerals and ores; and even the flow of liquids of high viscosity. Thus the invention may be of use in the elevating of liquids whose viscosity changes over time. In general terms, bulk flow of material may in this context be regarded as any flow of matter in contact with a surface, in which the effects of friction between the surface and the material usually influence the maximum flow rate, and in which the matter exhibits free flow behaviour.
U.S. Pat. No. 5,959,218 includes a discussion of the applications of mass flow meters, for measuring the mass flow rate of bulk materials, in the combine harvester art; and also a discussion of some prior art mass flow meters. The entire description of U.S. Pat. No. 5,959,218 is incorporated herein by reference.
The arrangement of U.S. Pat. No. 5,959,218 is a highly successful apparatus for measuring the mass flow rate of grains in a combine harvester, without reducing or interrupting the flow of grains. The invention seeks to provide additional advantages over those arising from mass flow meters such as, but not limited to, the U.S. Pat. No. 5,959,218 arrangements and methods.
In a combine harvester the grain elevator lifts grain between the grain cleaner and the bubble up auger that in turn transfers the grain to the grain tank. As a result of use of a combine harvester during a harvesting season, the chain defining a major part of the grain elevator stretches and slackens.
The chain is usually an endless ovaloid or similar shape that is wrapped at its lower and upper ends around, respectively, a drive sprocket (at the lower end of the elevator) and a tensioning (driven) sprocket (at the upper end of the elevator). It is therefore conventional to include a releasably securable mounting, for the tensioning sprocket, that is position adjustable e.g. in a direction parallel to the elongate axis of the ovaloid. The combine harvester operator or service engineer may release the mounting in order to take up slack in the chain, by repositioning the tensioning sprocket; and then re-secure the mounting.
The elevator chain supports a series of elevator paddles that move with the chain during operation of the elevator. The paddles pick up grain at the base of the elevator, convey it to the top thereof and then, by virtue of the loci of the paddles (that are dictated in turn by the shape of the chain) throw the grains outwardly at the top of the elevator. The trajectories of the grains are constrained by the interior walls of a hollow, concave elevator head that encloses the otherwise open upper end of the elevator.
The elevator head guides the grains to a bubble up auger that conveys the grains to the clean grain tank of the combine harvester.
In the flow path of the grains between the elevator and the bubble up auger it is known to install the sensor surface of a mass flow measuring device (meter) as disclosed in U.S. Pat. No. 5,952,584 or U.S. Pat. No. 5,959,218. Typically the walls of the elevator head act as a lead-in guide surface for guiding the grains into contact with the sensor surface.
The loci of the elevator paddles is arcuate in the vicinity of the top of the grain elevator. The top wall of the elevator head is generally of complementary shape to the loci of the paddles in this region. Consequently the spacing between the free edges of the paddles and the said wall is substantially constant, at least over a certain length of the top wall.
A proportion of the grain conveyed by the paddles falls through the gap between the paddle ends and the elevator head top wall. As a result of re-tensioning of the elevator chain in the manner aforesaid, this gap diminishes. Consequently the proportion of the grain falling off the paddles via the spacing after re-tensioning also diminishes, with the result that grain flows at a more controlled speed onto the sensor surface, than before the re-tensioning operation, because the grain is influenced less by grain moisture content or kernel size.
Such a reduction in the proportion of grain falling off the conveyor paddles causes a greater proportion of the conveyed grain to impact the sensor surface of the mass flow measuring device at a controlled speed. This in turn increases the average speed at which the grain reaches the sensor surface.
The mass flow measuring device is calibrated in part on the assumption that the grains will impact the sensor surface at a known speed. Clearly the aforementioned change in average speed of the grains invalidates the assumption and thereby reduces the accuracy of the mass flow measuring device following chain re-tensioning.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided an elevator for bulk material having a hollow, upwardly extending elevator housing having respective lower and upper openings and substantially enclosing an endless, flexible conveyor for conveying bulk material. The bulk material entering the housing at the lower opening, to the upper opening. The elevator including a head assembly having a plurality of members secured together to define a hollow, rigid closure that closes the upper opening of the elevator housing. The elevator head supporting within the hollow, rigid closure a guide surface for guiding bulk material in the elevator head. The elevator head also includes supported within the hollow, rigid closure a sensor surface of a mass flow measuring device, towards which the guide surface guides bulk material following its elevation by the said conveyor and a rotatable drive transfer assembly for rotatably engaging and tensioning the flexible conveyor.
The elevator head includes a lever member extending laterally of the elevator beyond the sensor surface. The lever member being pivotably secured to a fulcrum that is fixed relative to the elevator housing, whereby on pivoting of the lever member about the fulcrum the elevator head and the components supported thereby move together. This permits adjustment of the tension in the conveyor without substantially altering the positions of the conveyor, the guide surface and the sensor surface relative to one another.
An advantage of this arrangement is that the gap between the paddle free edges and the elevator head does not change as a result of a chain re-tensioning operation. Consequently the accuracy of the mass flow measuring device is maintained.
Preferably the endless, flexible conveyor includes an endless chain supporting a series of bulk material elevator paddles that lift bulk material from the lower opening and project it towards the sensor surface at the said upper opening, the chain defining an upwardly extending ovaloid path of the said conveyor and being wrapped at the lower and upper ends of the ovaloid respectively around a drive sprocket; and
a tensioning sprocket that constitutes the said rotatable drive transfer assembly, whereby, on upward pivoting of the elevator head, the tensioning sprocket increases the tension in the chain. These features advantageously suit the elevator of the invention to use in a combine harvester.
In preferred embodiments the elevator head includes a mounting door supporting a mass flow measuring device
Busschaert Bart
De Busscher Cyriel Richard Jozef
Deleersnyder Serge Odon
Missotten Bart Marie Antoon
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