Patent Number: 050531859
Section: summary

BACKGROUND OF THE INVENTION The present invention generally pertains to material analyzers and is particularly directed to transporting materials samples to an activation region of the material analyzer for analysis. Material analyers are used to determine and measure the content of material samples. Prior art material analyzers are described in U.S. Pat. No. 4,582,992 to Thomas L. Atwell, James F. Miller, Ernesto Corte, Richard L. Conwell and Clinton L. Lingren and the publications cited therein. In a typical prior art material analyzer, a material sample is positioned within an activation region located between a radiation source and a detector disposed for detecting radiation that is secondarily emitted by a material sample within the activation region when the material sample is bombarded by radiation from the radiation source. The detector produces signals in response to the secondarily emitted radiation; and a computer processing the signals to determine the content of the material sample. The radiation source and the detector are disposed within a container and are shielded by radiation shielding material within the container in order to shield the outside of the container from radiation derived from the radiation source. In a prior art material analyzer designed to analyze bucket-size samples of material, the material sample is transported into the activation region from outside the container by use of a drawer that includes a sample containment chamber. The drawer is slid out from the container; the material sample is placed in the sample containment chamber; and the drawer is slid into the container to position the material sample within the activation region. After the material sample has been analyzed, the drawer is slid out from the container and the material sample is removed from the sample containment chamber. SUMMARY OF THE INVENTION The material analyzer of the present invention is an apparatus that includes a container; a radiation source disposed within the container; a detector disposed within the container for detecting radiation that is secondarily emitted by a material sample within an activation region located between the radiation source and the detector when the material sample is bombarded by radiation from the radiation source and for producing signals in response to said secondarily emitted radiation; a radiation shield within the container for shielding the outside of the container from radiation derived in the activation region from the radiation source; means for processing said signals to determine the content of the material sample; and means for transporting a material sample from outside the container to within said activation region; wherein the transporting means comprise a carousel, disposed about an axis of rotation located between the activation region and a receiving region located outside the container, and having at least one sample containment chamber that is moved between the receiving region and the activation region when the carousel is rotated about said axis. By using a carousel instead of a drawer to transport the material sample from outside the container to within the activation region, the apparatus of the present invention requires less space when being used, and thereby enables the use of the apparatus in a relatively small space such as the cargo compartment of a vehicle used to transport the material analyzer to a site where samples of the sampled material are being mined or otherwise produced. Another advantage of the use of a carousel is that the carousel may further include a second sample containment chamber located on the opposite side of the carousel from the first mentioned containment chamber; so that as one material sample within one sample containment chamber is disposed within the activation region and being analyzed, the previous material sample is removed from the second sample containment chamber and the next material sample is placed within the second sample containment chamber, thereby significantly increasing the rate at which samples can be analyzed. Also, by providing oppositely disposed sample containment chambers in the carousel, no significant change occurs in the center of gravity of the carousel as the sample is transported from outside the container to within the activation region. This obviates the need to provide counterweights, as may be required when a drawer is used. In an embodiment in which the radiation source is disposed below the sample containment chamber when the sample containment chamber is in the activation region, and the detector is disposed above the sample containment chamber when the sample containment chamber is in the activation region; the carousel further includes a radiation shield disposed laterally around the sample containment chamber in order to prevent the material sample and/or the detector from being bombarded by secondarily emitted radiation from materials within the carousel that are disposed at the sides of the sample containment chamber. In another aspect, the present invention further provides a removable bucket dimensioned for placement within the sample containment chamber. The bucket includes a perimetric side wall having a predominant surface area that is contoured on opposite sides of the side wall to contain exterior indentations in said predominant surface area; and a handle, including a pair of tongs shaped and disposed for insertion into the side wall indentations, and telescopic handle joining the tongs so that the tongs can be moved toward each other to fit within the side wall indentations in order to grip the bucket and thereby enable the bucket to be transported by using the handle, and so that the tongs can be moved away from each other to enable the handle to be removed from the bucket after the bucket has been so transported. In a further aspect, the present invention also provides a sample mixer. The sample mixer includes a Y-shaped container having a hollow leg and two hollow arms that open into the leg, wherein each arm has an extended end that is closed, and wherein the leg has an extended end that is open and dimensioned to fit precisely against a rim at an open end of the bucket; a shutter attached to the extended end of the leg for movement between open and closed positions in order to prevent sample material from flowing out of the container from the extended end of the leg when the shutter is in the closed position and for enabling sample material to flow into or from the container through the extended end of the leg when the shutter is in the open position; and an axle, with the container being disposed on the axle for rotation about an axis that is normal to the leg so that sample material within the container can be mixed by rotating the container about the axle when the shutter is in the closed position. Additional features of the present invention are described in relation to the description of the preferred embodiment.