Abstract: A method of ore sorting includes distinguishing ore objects or ore containing objects by the light reflected from a laser beam arranged to scan across each of the objects to be sorted. Where the surface of the object is transmitting to the light a halo is produced by certain objects caused by internal scattered reflections of the light. By monitoring the occurrence or degree of occurrences of halos clean distinction of respective objects can be made. In a particular application, the identification of the presence of quartz pebbles in rock specimens can be used for detecting and sorting gold containing objects.

Abstract: An electrostatic shield for an electrical conductor element comprises a sheet-like array of closely spaced elongate electrical conductors interconnected at one end of the array by an end conductor for connection to a common or ground potential. The conductor to be shielded may be in the form of a loop or coil printed on one face of an insulating plate and the array of shielding conductors and the end conductor may be printed on the other face of the insulating plate. The shield may include two or more series of parallel conductors arranged in adjacent banks and each provided with a separate end connecting conductor.

Abstract: Apparatus for sorting ore rocks in which rocks are fed in stream past detector to measure characteristic selected as basis for sorting and into free flight trajectory from which selected individual rocks are deflected according to measure of said characteristic for those rocks. Apparatus is characterized by rock feed means comprising pair of movable elements having surfaces defining upwardly facing nip and which move downwardly at nip to grip rocks and accelerate them downwardly into free flight such that the free flight trajectory is substantially vertical.The movable elements may be a pair of horizontal rollers having resiliently deformable peripheral surfaces or a pair of flexible endless belts arranged in loops having upper parts defining the nip and, below the nip, adjacent downwardly extending runs between which the rocks are gripped and moved downwardly for some distance below the nip before being projected into vertical free flight.

Abstract: Feed apparatus and method for feeding objects such as ore rocks in such a way that they are arranged into at least one moving stream of spaced apart objects. The objects are fed onto a first conveyor belt which may have longitudinal channels to arrange the objects into moving rows. The moving objects are projected from end of the belt in free flight path and caught on downwardly moving section of a second belt which passes to a horizontal run via a concavely curved belt section so that objects are stabilized on the second belt by centrifugal action to emerge on horizontal run as one or more fast moving streams.

Abstract: Method and apparatus for sorting objects according to the degree to which they possess a required characteristic. Objects are moved in a line on a conveyor belt past a line of detectors each responsive to the required characteristic. Each detector produces a time sequence of output signals and the signals from successive detectors are accumulated. The objects are projected from the downstream end of the conveyor belt in a free flight path past an optical scanner and a series of air blast nozzles. The scanner determines the portions and sizes of the objects and objects selected on a comparison of the detector signals and signals from the scanner are blasted with air jets from appropriate nozzles so as to be deflected from their free flight trajectory. Deflected and undeflected objects are caught in separate collection bins.

Abstract: Method and apparatus for bulk sorting particulate material such as ore rocks. A conveyor belt carries the material in a continuous stream past a detector responsive to a required characteristic to produce a time sequence of detector signals dependent on degree to which material passing the detector possesses that characteristic. The material is projected from the downstream end of the conveyor belt into free flight trajectory and a deflector plate is moved across the face flight path so that material in some zones of the stream is deflected whereas material in other zones is not deflected. A control circuit monitors the detector signals and causes the deflector plate to move so that said zones are determined by the degree to which the material in them possesses the required characteristic.

Abstract: A fluid flow manifold to deliver pressurized fluid to a series of outlets from a common supply duct has a block body and fluid outlets disposed in linear array along one side of the block. Valves are spread over an opposing side of the body block and connected to the fluid outlet by outlet ducts extending transversely through the block. A supply duct extends longitudinally through the block and delivers fluid to the valves via transfer ducts. The valves are spread in cylindrical array about an axis extending along the linear array of outlets and the outlet ducts converge radially to converge into a linear array defining the fluid outlets such that lengths of all outlet ducts between the valves and the fluid outlets are equal.

Abstract: A rapid response valve particularly suited for controlling a jet of fluid of variable duration, the valve having a chamber with a valve seat surrounding a valve orifice, a valve member within the chamber movable toward and away from the valve seat, the chamber having an inlet compartment and an outlet compartment, means being provided to effectively balance the fluid pressure on opposite sides of the valve element when in the closed position so that the valve may be rapidly moved to the open position when actuated, means also being provided to create a venturi effect to assist in rapidly returning the valve to its closed position.

Abstract: In the photometric sorting of objects each object is examined in each of a predetermined number of zones for the presence or absence of one or more predetermined surface characteristics. The invention provides that a characteristic determined in one zone be attributed to at least one other zone into which the object extends.

Abstract: A tracking system for a sorting apparatus for sorting pieces of material moving through a sorting zone in a wide path random stream has a light scanning device which makes repeated scans across the sorting zone to detect light reflected from the pieces of material, and downstream of the scanning device a plurality of deflection devices extending across the sorting zone. An electronic control generates timing signals which, in effect, represent a plurality of overlapping analyzing channels extending in the direction of movement of the pieces of material and overlapping one another across the sorting zone. An electrical circuit arrangement for each analyzing channel receives signals from the scanning device and accumulates information relating to pieces of material in that channel and provides a decision signal based on the accumulated information.