Abstract: A comminuting apparatus for rubber has two vertically mounted opposing facing grinding stones of large size having hollow centers. Interposed between these two stones, both of which, as stators, are fixed and do not rotate, is a single rotor having double-sided opposed abrasive grinding stone faces, mounted for rotation but floating laterally or horizontally in position between the two opposed fixed stones. The spacing between the opposed sets of grinding stones is set by increasing or decreasing the spacing between the outer most stator and the fixed inner stator. So long as the rotor rotates for grinding, the floating center stones will position themselves equally between the two stators so as to equalize the dynamic slurry pressure imposed during the grinding process upon the faces of the stones.

Abstract: A rotary disintegrator for liquid-borne solid waste, for example, has a cutter head (14) in which a rotatable headstock having cutting blades (28, 30) is urged by springs (38) against a shear plate (15). A signalling means for signalling predetermined wear of the shear plate (15) by the cutting blades (28, 30) includes a wear detector (65) having a rod electrode (67) mounted by an insulating plug (72) within a bore (74) in the shear plate (15). When the plug (72) is worn by the cutting blades to expose the electrode (67) the electrical circuit of the signalling means is completed thus providing an indication that a predetermined degree of wear of the shear plate (15) has occurred.

Abstract: A roll mill has a fixed roll journalled in stationary fixed bearings and a floating roll journalled in movable bearings enabling the floating roll to be pressed against the fixed roll under high pressure. An adjustable spacing arrangement is provided between the two bearings to enable a gap of selected width to be formed between the rolls. The spacing arrangement includes a pair of shaft-like distance members received and guided in associated bores of the fixed bearings for movement therealong. Free ends of the distance members extend outward of their bores and engage the opposing floating bearings to adjust the positions of the rolls as they wear so as to maintain the selected gap width. The free ends are retractable into the bores to allow the bearings to abut one another and thereby optimize the wear life of the rolls.

Abstract: An apparatus convertible between chopping or shredding operations and grinding operations. The centrifugal grinder or chopper includes two opposed plates with at least one plate rotating with respect to the other. A plurality of shearing plates are rigidly but removably secured to one mounting plate while a plurality of grinding segments or chopping and shredding knives are rigidly but removably secured to the other mounting plate. Each shearing plate includes a curved rib extending outwardly toward the other mounting plate. When one of the mounting plates is rotated with respect to the other, material is forced centrifugally outward into spaces or grinding chamber segments and chopped or ground before passing out of the spaces or grinding chamber segments and into an outlet. An automatic gap adjustment mechanism is further disclosed for setting the desired gap between the ribs of the shearing plates and the grinding segments or chopping and shredding knives.

Abstract: The invention proposes a novel automatic product feed in which an analog signal is formed and at least one other digital signal which is adjustable independently of the analog signal is generated and used for the automatic product feed for supervising the product feed functions by a mechanical probe (8) in the product flow. In this way, all previously known controlling and regulating functions can be realized with a minimum of electronics or at the highest level of computer control as a function of the product feed or for optimizing the grinding conditions, possibly with externally initiated digital signals for various stage adjustments and with the use of very simple automatic component means. The invention further proposes a corresponding method for grinding with a milling roller mill (1).

Abstract: The invention provides an apparatus for crushing material such as rock and includes a support structure having an inlet and an outlet. A powered rotor shaft rotates with respect to the support structure about a shaft axis, and a rotor mounted eccentrically on shaft describes orbital motion about the shaft axis. The rotor has a rotor wall which moves cyclically and laterally with respect to the axis during the orbital motion. At least one stator is mounted in the support structure to provide a stator wall spaced oppositely from the rotor wall to define therewith opposing walls of a crushing chamber located between the inlet and outlet. Feed direction of material passing between the inlet and outlet is generally perpendicular to the shaft axis, and when the rotor describes the orbital motion, spacing between opposing walls of the chamber varies cyclically. The stator is mounted yieldably so as to move away from the rotor when a pre-determined threshold force is exceeded so as to reduce possible damage.

Abstract: In an apparatus (10,100,300,400) for refining a low consistency fibrous slurry, which includes a plurality of refining zones (38,40; 188,128; 324,334; 411,413) within a casing, the improvement comprises providing a unique discharge flow path from each refining zone to a respective unique discharge line (56,58; 130,142; 308,310; 411,413) out of the casing, and means (57,59; 141,143; 344,346; 432,434) for differentially adjusting the flow rate in each discharge line. In accordance with the preferred embodiment of the invention, a divider (42,132,340) is provided between the casing and the rotor member, thus dividing the discharge between the two refining gaps, into two separate flow streams. The first and second gaps are monitored in any conventional manner. Under operating conditions, the flow control valves are adjusted for combined flow from the refiner casing as required by the production demands.

Abstract: In a forage harvester which has an automatically adjustable shearbar mechanism for adjusting the distance between the shearbar and a rotating cutterhead, rotation of the cutterhead is determined by the use of essentially steady state signals without substantial transient components.

Abstract: An apparatus for fragmenting a block of frozen vegetable tissue such as peat moss, without causing wide-spread damage to the individual vegetable fibers, comprising a pair of planar jaw members movable between opened and closed positions. Each jaw member has a grating-like configuration defining a plurality of discharge apertures in a spaced apart relationship and also comprises projecting crushing teeth. In the closed position, the jaw members are in a mating relationship, whereby the crushing teeth of each jaw member deeply penetrate the discharge apertures of the opposite jaw member. In operation, a block of frozen vegetable tissue is loaded between the jaw members while they are in the opened position. The jaw members are closed for bursting into fragments the block of frozen vegetable tissue under the effect of multiple pressure points created by the crushing teeth on the block surface and for expelling the fragments through the discharge apertures.

Abstract: Relates to the automatic operation and control of a surface treating device having a powered tool and a work wheel for engagement with a work piece, said device being carried on a robotic arm and being adapted to maintain a uniform pressure of engagement of said work wheel with a work piece and a uniform rate of speed of the working surface of said work wheel in its engagement with the work piece, and a balancing pressure applied to said powered tool and work wheel to in effect make them weightless for their precise control.

Abstract: The fineness of bulk material, particularly of material to be ground, is determined by means of a flow measurement (DIN 66126) and by using a calibration correlation between medium particle size and permeability of the sample.The medium fineness of a continuous flow of bulk material determined in such a way at predetermined intervals of time may be used for adjusting roll mill parameters. In the same way, it is possible to calculate the bulk density, so that a compacting procedure subsequently to a milling procedure can be adjusted accordingly.

Abstract: This invention relates to a method of refining pulp stock in which the pulp material to be ground is introduced into a grinding space located between a first rotatable grinding device carried by a shaft and being axially displaceable by a servo motor, and a second non-rotatable grinding device. The servo motor is actuated by pressurized fluid for adjusting and controlling the grinding space, producing a grinding pressure between the first and the second grinding devices and for preventing axial displacement of the first rotatable grinding device relative to the second non-rotatable grinding device in response to fluctuating axial grinding forces. The second non-rotatable grinding device comprises a plurality of concentrically arranged annular grinding members, at least one of which is axially adjustable by a setting device.

Abstract: The present invention provides a roller mill control method capable of automatically controlling a roller mill which is comparatively difficult to operate for operation in an optimum operating condition, and a roller mill controller for carrying out the roller mill control method. The roller mill controller stores beforehand a roller mill characteristic model representing the relation between changes in the values of the operating condition variables detected by a detecting unit (2) and operating parameters, restrictions on the values of the operating condition variables and the operating parameters, an index of performance for evaluating the values of the operating condition variables and the operating parameters.

Abstract: The invention relates to the comminution of brittle material for grinding in a material bed roll mill with two grinding rolls, in which the material for grinding is comminuted between the cylindrical surfaces of the grinding rolls by the application of a grinding force. In order to prevent damage to the roll surfaces due to excessively high surface pressures but to utilise the maximum capacity without exceeding it, the roll surface pressure is continuously monitored and when an upper limit is exceeded the pressure is reduced to a permissible value by reducing the grinding force.

Abstract: A method is described for controlling the grinding of a dispersion of solid particles in a doughy-pasty mass, such as a chocolate mass, on a roller mill line having at least one preceding and one postponed roller mill (1 or 4), of which at east the postponed roller mill (4) is a roll refiner mill with a plurality of rollers (W1-W5). In this arrangement, the outlet roller gap of the preceding roller mill (1) is changed for decreasing or increasing the layer thickness of the mass in the postponed roller mill (4) having at least three rollers. Additionally and besides changing the outlet roller gap of the preceding roller mill (1) a control of the layer thickness of the postponed roller mill (4) is carried out according to a proportional-integral-differential control system.

Abstract: An apparatus for sorting particles of a bulk material moving on a transport ribbon (38) comprises an electro optical monitoring unit (101) above transport ribbon (38) for detecting the particles to be sorted out. Jet nozzles (45, 46) are controlled by a signal emitted by this electro optical monitoring unit (40), the jet nozzles being provided at the side opposite the bulk material of transport ribbon (38), which consists of an air permeable material. By means of the gas jet passing through transport ribbon (38), the particles to be sorted out are lifted off from the transport ribbon and are thrown into storage containers (47, 48). The bulk material is passed through a gap between rollers or grinding elements to provide flake-shaped particles which are then observed to provide first and second measurements which are subtracted from each other.

Abstract: A high pressure roller press for interparticle crushing of material including opposed crushing rollers with at least one roller being movable, a gate controlled material feed to the nip of the rollers, means measuring the nip width by measuring the distance between bearings of the rollers, means measuring the nip force by measuring the hydraulic pressure applied to the movable roller to obtain nip force, a comparator receiving signals of nip width and nip force and having an output to maintain a linear relationship between nip width and nip force and controlling the feed to the nip and the nip width to maintain the relationship.

Abstract: In an apparatus for producing milled grain products by means of repeated roll grinding and sifting of specific product fractions, the material to be milled is at least partially guided via double-grinding passes without intermediate sifting. An eight-roll mill is used for this purpose, which eight-roll mill is constructed as a double unit with two roll pairs arranged at a distance one above the other and can be used in quantity in a grain milling system or also in combination with single-grinding passes constructed as four-roll mills. Compared with the use of known four-roll mills, the economic efficiency of a mill is accordingly improved while completely retaining the adaptability of the mill to specific grinding tasks, the quality of the material to be milled and/or the ability to monitor the grinding process.

Abstract: The invention proposes a novel automatic product feed in which an analog signal is formed and at least one other digital signal which is adjustable independently of the analog signal is generated and used for the automatic product feed for supervising the product feed functions by a mechanical probe (8) in the product flow. In this way, all previously known controlling and regulating functions can be realized with a minimum of electronics or at the highest level of computer control as a function of the product feed or for optimizing the grinding conditions, possibly with externally initiated digital signals for various stage adjustments and with the use of very simple automatic component means. The invention further proposes a corresponding method for grinding with a milling roller mill (1).

Abstract: A conveyor system for a coffee grinder for taking ground coffee from the grinder to the packing machinery, and a laser test-meter used to analyze the granulometry of ground coffee test samples and compare them with a granulometric reference sample that are known. The system of the invention includes improvements which include a first device which continually receives undisturbed ground coffee samples and delivers these samples to a second device in which a gas stream blows a stream of coffee grains down a tube to the test-meter and a second stream of gas flowing at right-angles to the tube disperses any partially aggregated particles before they reach the test-meter. A third device creates a pressurized safety area around each lens of the laser test-meter. The area is partly closed so that laser beams can freely pass, and gas under pressure enters the area preventing coffee grains from entering the area and disturbing the lens.

Abstract: A bearing system in a refiner for making pulp, where the raw material is refined in a refining gap between at least one pair of refining members (22, 24) rotating relative to one another, where at least one of said refining members (24) is supported by an axially movable and rotary shaft (26 ). The bearing system comprises a combined hydrostatic/hydrodynamic axial bearing arrangement and consists of a cylindric housing (32) with at least one rotary cylindric piston (30), which is mounted on the rotary shaft (26) for rotating together with the same. At least one outer and one inner concentric ring cylinder (200, 202 and, respectively, 210, 212) are arranged to abut one of the end surfaces of the rotary piston (30), so that a sealing gap is formed.

Abstract: The fineness of bulk material, particularly of material to be ground, is determined by means of a flow measurement (DIN 66126) and by using a calibration correlation between medium particle size and permeability of the sample.The medium fineness of a continuous flow of bulk material determined in such a way at predetermined intervals of time may be used for adjusting roll mill parameters. In the same way, it is possible to calculate the bulk density, so that a compacting procedure subsequently to a milling procedure can be adjusted accordingly.

Abstract: The invention relates to an air flow rolling mill for comminuting hard minerals such as slag or cement clinker. The discontinuities in operation occurring with high fineness levels are overcome in that with the grinding rollers are associated compression rollers for making the grinding bed uniform.

Abstract: The width of the clearance between a rotor with orbiting beaters and a pivotable impact plate of a machine for comminuting coal, rock, and like materials is adjusted by a computer which controls a reversible motor serving to pivot the impact plate relative to the path of orbital movement of the beaters. The computer causes the plate to pivot toward the path of the beaters when it receives a signal that the admission of material into the housing of the comminuting machine is interrupted and a converted acoustic signal denoting that the machine generates sounds which are indicative of completed evacuation of material from the housing. The direction of pivotal movement of the plate is reversed when the computer receives a series of converted acoustic signals or a single converted acoustic signal denoting that the width of the clearance has been reduced to zero, i.e., that the beaters actually strike the adjacent portion of the plate.

Abstract: A grinding clearance adjustment device for milling roller frames is disclosed, in which a casing contains two grinding rollers, one of which is constructed as a pivotable loose roller. Adjustment members, for the rollers are provided, as well as a device for the automatic setting of the grinding clearance by means of a remotely controllable drive motor, the latter being coupled to the adjustment members via transmission means. The motor operates through a clutch. In the preferred embodiment, the adjustment members are constructed as a first closed standard component, which has a lever-transmitted setting part with a longer and a shorter lever arm and which is laterally positioned in the vicinity of the grinding rollers. The drive motor and clutch are constructed as a second closed standard component, which is spaced from the first standard component, and the adjustment forces derived from the drive motor are coupled to the longer lever arm of setting part.

Abstract: A device for processing materials such as rock, ore, clay, bulk materials and agglomerated pulverized materials includes at least two tools having working surfaces thereon of at least partially circular cylindrical cross section. The tools are oriented such that the working surfaces thereof are in opposed horizontally spaced relation, and the device includes a mechanism for moving at least one of the tools with an up and down pendulum motion about the respective axis thereof. The tools include upper surface portions and lower surface portions, and the upper surface portion of at least one of the tools has a plurality of comminuting projections thereon for preprocessing relatively large sized materials. The lower surface portions of the tools are substantially smooth, and they are positioned in closely spaced relation for processing materials therebetween to form a finely milled and product.

Abstract: Disclosed is a device for automatically adjusting the roll gap between the rolls of a roll mill including simultaneously operated screw jacks which adjust the gap and a shaft mounted geared box drive to accomplish the drive of the secondary roll from the primary roll further including a drive tensioning device which permits automatic adjustment of the roll gap while maintaining tension between the drive belts utilized for driving the shaft mounted gear box. The combination permits the automatic selection and adjustment of roll gap without further adjustment to accommodate the drive to the different roll gap settings.

Abstract: The present invention provides a regulator for a refiner or grinding apparatus having opposed relatively rotatable grinding discs. Each grinding disc carries a grinding segment, and a predetermined gap or grinding space is defined between the grinding segments. The regulator, which is provided to compensate for axial variations in the predetermined grinding space due to variations of the load, includes a piston axially movable in a cylinder and a calibrated resilient element acting on the piston. The regulator is coupled to a hydraulic servo motor for the grinding discs, and the dimensions of the piston and cylinder of the regulator are selected to correspond to that of the servo motor, but in reduced scale. By calibrating the resilient element of the regulator to correspond to the axial load applied to the grinding discs, the displacement of the regulator piston corresponds to the relative displacement of the grinding disc and thus to a variation in the grinding space between the grinding discs.

Abstract: In a milling apparatus for milling granular material into milled particles, a roll mill includes a pair of rolls which are rotatably arranged in facing relation to each other. At least one of the rolls is movable toward and away from the other. A gap adjusting unit is associated with the at least one roll for moving the same toward and away from the other roll to adjust a gap between the rolls thereby adjusting a milling degree of the milled particles. A measuring unit is arranged downstream of the roll mill and is connected to the gap adjusting unit thereof for measuring the milling degree of the milled particles. The gap adjusting unit is operative in response to an output signal from the measuring unit to move the at least one roll toward and away from the other roll, thereby automatically adjusting the milling degree of the milled particles. A milling system is provided which includes at least two roll mills described above.

Abstract: In a forage harvester, a shear bar is adjusted relative to the knives of a rotating cutterhead by selectively energizing first and second motors to move one or the other end of the shear bar toward the cutterhead. A vibration sensor senses vibration of the shear bar and controls a circuit to deenergize an energized motor when vibration is induced in the shear bar. The vibration may be caused by impact of the cutterhead knives on the shear bar (a true hit) or by random noise (detected as a false hit). To discriminate between false hits and true hits, an energized motor is stopped when a first hit (true or false) is detected. A timer is set to time an interval at least as great as the time it takes the cutterhead to make one revolution, and during this interval the vibration sensor is repeatedly sampled to determine if a second hit has occurred. If a second hit is detected during the interval the first hit is assumed to be a true hit.

Abstract: A scrap metal crusher includes a tapered chamber having a relatively large inlet at one end and a relatively small outlet at the opposite end of the chamber. A rotary crusher arm is axially mounted for rotation in the tapered chamber. A plurality of vanes are disposed along the inner surface of the tapered chamber, which vanes in cooperation with the rotary crusher arm convey scrap inserted into the inlet of the tapered chamber toward the outlet of the chamber while simultaneously crushing the scrap. A throat disposed adjacent the outlet of the chamber allows passage of crushed scrap therethrough to a discharge chute. The throat is automatically enlarged upon jamming of the crusher to permit any material causing the jamming to pass through the throat to the discharge chute.

Abstract: Mechanical cellulosic fibrous material pulp (mechanical pulp to produce paper products) having lower freeness, and enhanced light scattering properties, tensile and tear strengths, for a given energy input, is produced by force feeding a refiner. Using a progressive compacting plugscrew, cellulosic material (e.g. wood chips) is fed to the refiner inlet at a rate greater than the transporting capacity of the refiner (e.g. about 10-40% greater). The refiner preferably is a low frequency conical refiner with steam removal at the grinding area between the conical refiner elements. The production rate is regulated by sensing the axial force on the refiner rotor and controlling the spacing between the refiner elements in response to the sensed axial force. The screw has a compaction ratio of at least 3/1 for wood chips and 6/1 for pulp, and is rotated at about 6-10% the speed of rotation of the refiner rotor.

Abstract: There is disclosed a vertical mill comprising a rotatable table and rotatable grinding rollers disposed on the upper surface of the table near the outer periphery of the table. Raw material is supplied to the central portion of the table. A given grinding pressure is applied to each grinding roller to crush the raw material between the upper surface of the table and the outer surface of each grinding roller. Rotatable auxiliary rollers are arranged alternately with the grinding rollers on the upper surface of the table near the outer periphery of the table. The layer of the material caught by the grinding rollers are compacted by the outer surfaces of the auxiliary rollers. There is also disclosed a method of operating the vertical mill. The method consists in separating controlling the grinding pressures applied to the grinding rollers according to the loads on the grinding rollers.

Abstract: An improved cone crusher wherein raw material is crushed between a gyrating mantle and a bowl liner above the mantle. Space between the mantle and the bowl liner is adjusted by moving the bowl liner upward, and the adjusting movement is automatically performed by hydraulic pressure applied evenly to the entire circumference, successfully meeting fluctuation of load and abnormal overload.

Abstract: Methods for determining the contact position between a pair of relatively rotating refining surfaces are disclosed including detecting the heat radiating from the initial contact between the pair of refining surfaces during relative rotation therebetween in order to generate an output signal and utilizing the output signal to determine the contact position. Apparatus for determining the contact position is also disclosed.

Abstract: The invention relates to a material bed roller mill with a fixed roller and a floating roller which between them form a grinding gap and a hydraulic-pneumatic spring system which presses the floating roller in the direction of the fixed roller and contains at least one hydraulic working cylinder and a working pneumatic spring which cooperates therewith for each side of the floating roller. The spring container of each working pneumatic spring is divided by two movable pistons into a central gas filling chamber and two opposing hydraulic fluid chambers, and a stroke measuring device is associated with one piston for the preliminary filling pressure of the hydraulic fluid. In this way it is possible to reset the grinding force during operation by means of the hydraulic pressure with the same pneumatic spring characteristic on both sides of the floating roller.

Abstract: A method of conical crushing to achieve the grinding of feed material includes narrowing the crusher setting beyond the specified minimum limit to enable the head to periodically exert high levels of compressive crushing force, interspersed with low pressure relief periods for mixing of the particles, the cycle of crushing periods corresponding with the gyrational cycle of the head. The method also includes increasing the releasing force exerted upon the crusher bowl to promote the grinding action of the crusher at its narrowed setting.

Abstract: A method of refining fibrous material under predetermined conditions by the help of relatively rotating refining means. The material is during refining passed from the inner circumference of the refining means to their outer circumference and is thereby exposed to bending forces and axial forces. At least two variables of the refining process, such as power and gap width are measured. The measured values of the variables and their relation are used to compare them with the set point values of the predetermined refining conditions for these variables to create control signals for positioning devices for the refining means, thereby returning the refining process to the aforementioned predetermined conditions and keeping these dependent variables constantly at these conditions.

Abstract: An automatic forage harvester shearbar-cutterhead clearance adjusting system includes motors connected to conventional left and right shearbar adjusting mechanisms. A knock sensor senses contact between the shearbar and the rotating knives of the cutterhead. A control unit including a programmed microprocessor controls the motors and, responding to signals from the knock sensors, automatically adjusts the shearbar-cutterhead clearance. The control unit prevents machine damage by responding to various fault conditions.

Abstract: In a method for setting the spacings of grinding rollers (2, 2') in roller frames (1) of a cereal milling plant, the roller frames are in each case followed by a screening system (14), from which a test signal is tapped and supplied to a computer (7), which compares it with a stored desired value and in the case of a variation brings about an automatic adjustment of the spacings of the grinding rollers by means of a control signal and adjusting means (4, 5). The test signal is only derived from the screen reject material (17) or screenings (18) of screening system (14) and is only supplied from certain selected key passages to computer (7). In a cereal milling plant for performing this method, a momentum weight measuring system (24, 29, 30, 31) for the continuous determination of the sifting work is associated with the gyratory sifter or sifters (14).

Abstract: A grinder refinement mechanism for use with a conventional coffee or peanut grinder is disclosed. The grinder includes the usual screw conveyor having a rotary grinding burr attached to a forward end thereof, a stationary grinding burr connected to a wall of the grinder housing and a main spring which biases the screw conveyor toward the forward end of the grinder housing against an adjustment screw projecting through an end wall. The mechanism includes a lever arm pivotally attached to an outside surface of the end wall and an electrical solenoid connected to the arm. The usual adjustment screw is replaced with a plunger element which slidably projects both into and out of the end wall and is confined between a forward end of the screw conveyor and the arm. In one condition of the solenoid, the main spring forces the screw conveyor and plunger forwardly to hold the arm against a stop screw which thus determines the desired coarse grinding condition of the grinder burrs.

Abstract: This invention is related to a method and device for measuring the distance (.delta.) between the discs of a refiner, in which method a magnetic field is generated by means of a coil (5) placed at one disc (4), which magnetic field is allowed to run at least partly through the other disc (3). According to the invention the measuring is carried out by using the actual distance between the refiner discs as the object of measuring in that the magnetic flux over the distance between the discs caused by the coil (5), which is formed at least at one refiner-disc tooth (7) or comparable element, is measured such that the flux running over the distance between two opposite teeth (7,8) is detected by means of another coil (6), such as is formed round at least either of said teeth, the signal induced in the coil being interpreted as a quantity that expresses the distance (.delta.) between the teeth.

Abstract: A method for controlling a crushing gap width of a gyratory crusher of the kind including a crusher head is disclosed. The crusher head of the crusher is driven by a power unit and is positionally adjustable in relation to a crusher shell by a hydraulic motor. The hydraulic motor moves the crusher head of the crusher, thereby adjusting the crushing gap width. A power consumption of the crusher, pressure load on the crusher head, and the width of the crushing gap are determined continuously. The crushing gap width is controlled by being adjusted when the gap width is, above a pre-determined minimum gap width value, substantially in accordance with a control function which depends on both the power consumption and the pressure load, and which is so selected as to provide an intended crushing effect the material being crushed.

Abstract: An apparatus and method for measuring the gap, tram, deflection, and wear of rotating grinding plates wherein inductive sensors are mounted in a recessed manner inset from the surface of a first grinding plate and located opposite recessed non-wear surfaces of a second grinding plate, thereby providing data by which plate gap and plate wear may be derived. A plurality of such sensors provide data by which plate tram and/or deflection may be deduced.

Abstract: A method and apparatus for measuring the spacing between a pair of surfaces, at least one of which is of electrically conductive and/or ferromagnetic material, so that the wear of one of the surfaces can be determined. A measuring transducer having a core with coils, and a reference transducer substantially identical to the measuring transducer, are the basic elements. The measuring transducer is mounted close to an opposing surface of conductive and/or ferromagnetic material with a gap between them, and the reference transducer is mounted with a constant gap spacing between it and a reference surface of the same material as the opposing surface.

Abstract: A pulverizing mill for reducing mineral samples includes a cowl arranged about pulverizing anvils and respective sample and air inlets pass through the cowl to the anvils. The cowl forms a confinement about the anvils so that during pulverizing operations the pulverized samples is directed thereby to a suitable receiver. During subsequent clean operations the cowl encloses the anvils so that an air blast may be introduced thrugh the air inlet to scour the anvils and clean the interior of the cowl.

Abstract: Under the control of a microprocessor first and second motors alternately drive first and second ends of a shear bar for adjusting the position of the shear bar relative to cutter head. The shear bar is adjusted so that it is substantially parallel to the cutter head even though the cutter head and shear bar may not be parallel at the time the adjustment is initiated. A knock sensor is provided for sensing impacts between the cutter head and shear bar, the knock sensor output signal being converted to a digital value for controlling the adjusting sequence. A knocker is provided for inducing vibrations in the shear bar to thereby test the operability of the knock sensor and its output circuitry. The sensitivity of the adjustment system to the output of the knock sensor is set automatically before an adjustment sequence begins to account for variations in the knock sensor, its output circuitry, and "noise" vibrations induced in the shear bar by normal machine operation.

Abstract: A method of controlling a bowl-mill crusher that has cylinders that remain in one position and roll over a rotating bowl with a predetermined force. Raw coal and primary air are supplied to the crusher and the crushed coal is removed from the crusher along with the primary air through a separator and supplied to burners through a pulverized-coal line. The pressure of the primary air where it enters the bowl-mill crusher is controlled in accordance with load and in a manner so that the pressure of the crushing cylinders against the bowl is decreased in a predetermined manner when the desired load-dependent level is not attained and is increased when the level is exceeded.

Abstract: A method and apparatus for adjusting the gap width between a rotatable crusher cone and a crusher housing includes determining a reference position of the crusher cone relative to the crusher housing, storing a first quantity representative of the reference position, rotating the crusher cone, moving the crusher cone to the reference position, moving the crusher cone from the reference position toward the crusher housing until a limit is reached and measuring the distance of the crusher cone from the reference position, storing a second quantity representative of the distance, repeating the preceding three steps a plurality of times while separately storing each of the second quantities, obtaining a new reference position based on each of the second quantities, and determining an operating position of the cone crusher based on the new reference position.

Abstract: Under the control of a microprocessor first and second motors alternately drive first and second ends of a shear bar for adjusting the position of the shear bar relative to cutter head. The shear bar is adjusted so that it is substantially parallel to the cutter head even though the cutter head and shear bar may not be parallel at the time the adjustment is initiated. A knock sensor is provided for sensing impacts between the cutter head and shear bar, the knock sensor output signal being converted to a digital value for controlling the adjusting sequence. A knocker is provided for inducing vibrations in the shear bar to thereby test the operability of the knock sensor and its output circuitry. The sensitivity of the adjustment system to the output of the knock sensor is set automatically before an adjustment sequence begins to account for variations in the knock sensor, its output circuitry, and "noise" vibrations induced in the shear bar by normal machine operation.