Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: A method of detecting impurities in a mass, such as detecting metallic and/or plastic particles in a stream of tobacco particles or filter material for tobacco smoke, includes the steps of moving the mass relative to a microwave field and/or vice versa, and analyzing the influence of the mass upon the microwave field. The analyzing step involves simultaneously measur- the actual values of a first and a second parameter of the microwave field, ascertaining the presence or absence of those changes of the parameters which are attributable to the presence of impurities in the mass, determining whether or not the changes are within an acceptable range, and generating signals for segregation of impurities-containing portions of the mass from the other portions when the changes are outside of the acceptable range.

Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: A resonator device for testing a material quantity in the tobacco-processing industry for existence of at least one foreign substance and/or for detecting at least one of weight, density and humidity level of the material includes a resonator housing having a through opening for the material to pass through and a testing region located inside the resonator housing to which the material can be moved at least in part. The device has at least one element that increases energy density of electromagnetic waves for increasing the energy density in at least a portion of the testing region.

Abstract: A method of detecting impurities in a mass, such as detecting metallic and/or plastic particles in a stream of tobacco particles or filter material for tobacco smoke, includes the steps of moving the mass relative to a microwave field and/or vice versa, and analyzing the influence of the mass upon the microwave field. The analyzing step involves simultaneously measure the actual values of a first and a second parameter of the microwave field, ascertaining the presence or absence of those changes of the parameters which are attributable to the presence of impurities in the mass, determining whether or not the changes are within an acceptable range, and generating signals for segregation of impurities-containing portions of the mass from the other portions when the changes are outside of the acceptable range.

Abstract: The density of a wrapped rod-like filler of tobacco or filter material for tobacco smoke is ascertained by causing successive increments of the filler to traverse beams of X-rays which, after having penetrated through small portions of the filler, impinge upon detectors forming a linear array and serving to generate (first) signals denoting the intensities of the respective beams. Such intensities are affected by the densities of the respective portions of the filler. The first signals are processed in a circuit together with one or more additional signals denoting the intensity or intensities of one or more beams which bypass the filler, and with one or more further signals furnished by one or more detectors which are shielded from the source of X-rays. The thus obtained (second) signal denotes the densities of successive increments of the filler and is used to correct the density of the filler, if and when necessary.

Abstract: The complex dielectric constant of successive increments of a stream of tobacco particles is indicative of the mass and/or moisture content of the tested increments. Instead of passing along two high-frequency resonators, as disclosed in German patent No. 43 42 505 to Stange, the stream is caused to pass through the inlets and outlets of the housings of two high-frequency resonators which are connected to a microwave generator and transmit high-frequency signals whose amplitudes are indicative of the complex dielectric constants. The signals from the two resonators are processed in a regulating unit wherein a circuit sums up the real and the imaginary parts of the complex dielectric constant.

Abstract: A pair of conveyor screws for rotating positive-displacement pumps, the conveyor screws including a rotor and a contra-rotor, wherein the conveyor screws comprise a screw spindle pump and rotate with zero contact in a bore and in flanks and rotate at the same speed, the conveyor screws form loss gaps and have the same thread depth, the same number of threads and flank profiles which are symmetrical. The conveyor screws include a tooth base positioned below a flank profile reversing point and a tooth head positioned above the flank profile reversing point, wherein a profile-produced loss gap height in an axial section on a pitch circle is kept constant for a specific rotor diameter by shifting the flank profile reversing point as a function of a rotor pitch.

Abstract: The density of successive increments of two neighboring rod-like flows of tobacco particles in a cigarette rod making machine is determined by an apparatus which employs a source serving to emit a divergent beam of X-rays across the paths for the two flows so that the radiation which has penetrated through and issues from the two flows is indicative of the density of the respective flows. Such intensity is ascertained by discrete X-ray detectors which transmit corresponding signals to an evaluating circuit. The latter compares such signals with a reference signal denoting the intensity of a portion of radiation which has bypassed the flows, and the evaluating circuit can further compensate for the difference, if any, between the distances of the two paths from the radiation source.

Abstract: The reliability of mechanical testing of the hardness of cigarettes with one or more pivotable weights is enhanced by modifying the results of such testing on the basis of signals which are obtained by optically scanning the diameters of successive cigarettes prior to mechanically induced deformation. Optical scanning is carried out by triangulation with a fixedly mounted measuring head. The signals which are obtained with mechanical testing can be further influenced by taking into consideration the moisture content and/or the temperature of tobacco in tested cigarettes.

Abstract: The density of a stream of tobacco particles at the underside of a foraminous belt conveyor is monitored by an array of X-ray detectors to generate signals each denoting the density of a different thin layer in successive increments of the stream. Such signals are processed into signals denoting the density of the entire stream, the filling power of tobacco, and the quantity of the surplus in the stream. The processed signals are used to adjust the trimmer which removes the surplus, to adjust the distributor which feeds the particles to the stream, to regulate the hardness of cigarettes and to adjust the quantity of the surplus.

Abstract: A continuous stream of tobacco shreds is built at the underside of the lower reach of an air-permeable belt conveyor by conveying tobacco shreds in currents of air which impinge upon the lower reach of the conveyor at a variable angle and at a variable speed. The density of various layers of the stream at a plurality of points at different distances from the lower reach of the conveyor is monitored by a device which directs X-rays transversely across the stream and has a uni- or two-dimensional detector with one or more rows of diodes exposed to X-rays which have penetrated through the stream. The signals which are thereby generated by the diodes denote the monitored density at the plurality of points and are scanned, evaluated and processed to actuate one or more servomotors which vary one or more parameters that influence the orientation of shreds in the stream, the density and/or other characteristics of the stream.