The present invention relates to monitoring systems for inventory levels, and, in particular, a communications based system for monitoring and maintaining inventory levels in agricultural feed bins.
Many industries, including the agricultural, concrete, and other bulk material handling operations, require ongoing observation and determination of the contents to provide for continuity of supply through timely reordering to prevent service interruptions. For example, large scale confinement operations for livestock store feed in numerous large feed bins with varying contents proximate the livestock facility. Moreover, a single operation may have multiple facilities, each with multiple bins. In as much as the needs of each facility differ based on species, age and diet regimen, there is little redundancy among the plurality of bins, requiring for monitoring of each to insure efficient continuity of operations. Furthermore, each feedstock may have a designated supplier having varying minimum shipment quantities and delivery schedules. Accordingly, it is imperative that the facility operators make regular determinations of inventory status for each bin on a frequent basis.
At present, even at large facilities such determinations are extremely difficult and generally prone to error. A typical feed bin is a domed cylindrical metal container having a conical top hatch for the delivery of the feed and a conical bottom material discharge chute.
Typically, the hatch provides the sole visual access for determining quantities therein. Accordingly, the facility personnel much scale each bin, and visually or with graduated measuring sticks, measure or estimate the quantity therein, record the relevant information, and upon return to the facility offices make determinations on which bins require resupply from designated suppliers in a time frame that obviates the possibility of a food shortage. Alternatively, the personnel might tap the bin and try to correlate the remaining quantity based on audible response. Both of these manual approaches are prone to estimation errors and missed readings that can lead to feed being ordered prematurely and belatedly. Such ordering mistakes, particularly for large operations, are very costly.
Various container measuring systems have been proposed for agricultural feed containers. None, however, are entirely satisfactory for the varying types of seed material that have to be handled within a facility, and none provide material assistance in maintaining proper levels throughout the facility to avoid shortages, premature purchasing and other costly incidents. For example, U.S. Pat. No. 5,847,567 to Kielb et al. discloses a microwave system for determining the distance between the top level of a liquid or solid in a tank. In addition to being costly, the system relies on a relatively flat surface for accurate measurement, typically not present in bottom discharge feed bins. The system is also highly prone to error at the bottom conical portion, whereat substantial material volume is carried. U.S. Pat. No. 4,065,967 to Beeston discloses a silo level indicating system using temperature sensors to detect the presence of material at varying levels in a bin. The system relies on temperature variations between a reference sensor at the top of the bin and the contained material. At extreme temperatures, hot and cold, the difference may not be sufficient to enable accurate determinations. U.S. Pat. No. 5,002,102 to Hosel discloses a light detector system for determining the fill level of fiber material in a container. The system also relies on a relatively flat upper surface for measuring the fill level, and like the sonic systems is extremely prone to error at the lower levels of the container. U.S. Pat. No. 5,164,555 to Brenton discloses a rotating paddle that is used to sense the level of material in a container to prevent overfill, rather than determine overall volume of the material remaining. U.S. Pat. No. 4,047,434 at Marsh discloses a sensor system mounted on the side walls of a silo that relies on the conductivity of the material for actuating the sensors for determining the fill level. While the silage contains sufficient moisture for establishing the requisite conductivity, the materials typically stored in feed bins are generally poor electrical conductors, thus erroneous readings are encountered.
The above patents are also primarily directed to providing on-site information regarding the fill level by varying visual displays. Thus, while overcoming the need for manual determinations of fill level, the information must be retrieved, dated and reorder procedures conducted elsewhere.
In view of the foregoing, it would be desirable to have an automated system for monitoring the level in each bin, and based on current information determine the reorder mechanism for ensuring timeliness and economy.
The present invention provides an affirmative measurement of feed levels in a bin by a vertically disposed series of pressure sensors carried on a flexible detector strap releasably mounted at the center of the containers. The sensors include radially projecting blades that deflect and actuate in response to the downward flow of material being discharged. The ability of the blades to dynamically rotate in the presence of movement allows for a more uniform detection of feed at the sensed level. The detector strap is easily mounted in conventional feed bins without requiring structural modifications or additions. The signals from the detector strap are routed to a local monitoring site permitting on-site determination of fill level. The signals from plural bins may also be routed to a central monitoring site. The local monitoring site is preferably provided with a programmable logic controller for periodically recording the level of the feed bin. The fill data is remotely retrievable for use in determining resupply needs. The system may also beneficially incorporate a modem communications link with a remote service monitoring site. The service monitoring site periodically retrieves fill data, determines fill level, reorder requirements and timing, and places an order with a designated supplier to ensure resupply in a time frame insuring feed continuity.
Accordingly, it is an object of the present invention to provide a container level detecting system that is easily incorporated into existing containers without structural modification.
Another object is to provide a container level monitoring system that is effective for varying materials contained in agricultural feed bins.
A further object is to provide a container level monitoring system that periodically records fill levels in container for retrieval by an off site service provider that determines procedures for reordering.