Abstract: An electronic balance includes a weighing means for producing digital output signals as a measured value in response to a force induced upon a tray, a first memory for storing the mass of a reference weight, a discriminator for signalizing the existence and non-existence of an object on the tray, a second memory for storing a corrected value obtained by differentiating between a measured value of the reference weight and the mass stored in the first memory when the discriminator signalizes that no object is placed on the tray, an arithmetic unit for correcting a measured value signalized by the weighing means in accordance with the corrected value stored in the second memory when the discriminator signalizes that an object exists on the tray, and an output unit for permitting of visual inspection of the arithmetic results obtained by the arithmetic unit.

Abstract: In the retailing of articles it is necessary to ensure that packages containing a plurality of articles fall within predetermined weight ranges. The invention is particularly but not exclusively concerned with the packing of bacon but applies to other articles in which:(a) predetermined weight of an article i.e. a slice of bacon is variable.The packages aree weighed at a first weigh station to determine whether they fall within a predetermined weight range or whether they fall within predetermined limits either side of said predetermined weight range. If the latter the packages are then fed to a second weigh station at which they are again weighed and according to the weight ascertained there, an operator is given an indication usually by lights as to the exact number of make weight pieces both in number and size which have to be added or subtracted to the package in order that the package shall then fall accurately within the predetermined weight range.

Abstract: A medical patient weighing scale is disclosed which comprises an elongated, flat, rigid pan, a plurality of thin, electronic bending beam load cells mounted in the pan, and a rigid, elongated, flat cover freely supported on the load cells. The cover is of sufficient size to support a patient in a supine position. The weighing scale is extremely thin, and may be conveniently mounted or stored when not in use. Accurate weight measurements are provided almost instantaneously on a digital display on the cover.

Abstract: This disclosure is concerned with a novel digital multi-point recorder that is microprocessor-controlled and enables impact printing from in back of the recorder paper to provide a front visible flat print-out of pages of on-line running summary data suited for operator viewing in industrial and similar locations, and providing a record for direct use in reports and logs.

Abstract: A device for selectively applying a test load to a weight-sensing control mechanism in an enclosed conveyor unit for feeding particulate material at a controlled rate. The weight-sensing mechanism continuously senses the weight of a variable quantity of material such as coal being conveyed through a predetermined reference zone and one or more load cells generate a voltage signal representative of the weight being sensed. The test load may be supported in the conveyor unit in either of two positions including a first position wherein it is supported independently of the weight-sensing mechanism and a second position wherein it is transferred to the weight-sensing mechanism for the purpose of calibration. The device includes a transverse shaft journaled in the conveyor unit and a pair of eccentric hubs mounted at opposite ends of the shaft, each hub being rotatably received in a connecting head portion of one of a pair of support rods adapted to suspend the test load.

Abstract: An improved scale testing cart for selectively positioning scale calibration weights on platform scales is disclosed. The scale testing cart has a weight bed for retaining selected calibration weights and has a tubular frame adjacent one end of the weight bed which is adapted for holding a fluid. A first pair of wheels is attached to the weight bed at a position adjacent the tubular frame and a second pair of wheels is attached at the end of the weight bed which is opposed to the tubular frame. A hollow member is positioned between the second set of wheels and is adapted to retain ballast. A lift bar for engaging a lifting apparatus is positioned substantially at the weight center-line of the cart. Located adjacent the tubular frame is a drive means which generally includes a drive engine, gas tank, and hydraulic drive pump for propelling the cart.

Abstract: An electronic weighing apparatus having a load pan, a load receiver forming part of a parallel construction and supporting the pan, weight compensating means, and at least one force-transmitting lever having a short arm and a longer arm, connected at its short arm to take up the force transmitted by the load pan, and connected at its longer arm with the weight compensating means, wherein a built-in calibrating device includes a calibrating lever having an arm connected via a coupling element in force transmitting relation with the load receiver such that the force-transmitting connection can be selectively established or broken.

Abstract: A combination weighing device, used for grouping a mass of articles having substantial variance in their weights into groups each having a substantially constant total weight, by weighing some of these articles by a plurality of weighing balances having automatic article loading and unloading means, summing up the measured weights successively in accordance with a predetermined set of combinations of the balances and, when the sum falls in a predetermined range of weight, supplying control signals to the unloading means of the corresponding balances to collect the articles from them and when no control signal is supplied to the unloading means due to lack of desired combined weight, the loading means of the weighing balance carrying the least weight is automatically actuated to add some articles to the balance to make it possible to obtain the desired combined weight.

Abstract: This invention relates to a method and apparatus for the automatic checkweighing of containers during the process of their manufacture, and particularly relates to the checkweighing of hot glass bottles during their transmit from a molding machine to a lehr where they are annealed.

Abstract: Disclosed herein is an automatically controlled weigh feeding apparatus including a container for prefilling with a substance, a device for discharging the substance from the container at a controllable rate, apparatus for weighing the substance being discharged and for producing an electrical signal proportional to that weight, a voltage to frequency converter connected to receive the electrical signals, a digital computer, apparatus coupled to an output of the voltage to frequency converter for inputting data signals to the digital computer, the computer being adapted to compute a corrective signal based on the input data signals received, and coupling apparatus coupled between the computer and the device for discharging the substance from the container for controlling the rate of discharge responsive to the corrective signal.

Abstract: A stabilization of the zero point of a digital display in a periodically operating weighing scale is accomplished by obtaining the difference between the then-present weight signal S and a stored reference signal, for example the tare value. Resulting differences less than a predetermined threshold value are stored. If the next following difference signal is again smaller than the threshold value and has the same sign, the reference value is corrected by the stored difference. If the signs are different, the tare or reference value remains the same and the value of the stored difference signal is changed to the newly-generated value.

Abstract: To achieve an automatic stabilization of the zero point in a scale having a digital display, any difference between the load proportional signal and the stored reference signal (for example, the tare value) is compared to a threshold value. Differences which are less than the threshold value are halved in a divider. The halved difference signal is then used when the next subsequent one of the load proportional signal is compared to the reference signal, preferably by algebraic addition of the halved difference signal to the reference signal.

Abstract: An ice cream making and packaging machine is provided having an automatic overrun controller for controlling the amount of air mixed with the ice cream mix prior to freezing. The overrun controller includes a mix pump and a regulator for adjusting the amount of air to be mixed with the ice cream mix in the mix pump. The ice cream making and packaging machine continuously packages predetermined quantities of ice cream in containers and includes a conveyor system for continuously carrying the containers of ice cream through a weighing station. Measuring equipment associated with the conveyor measures the relative amounts of air and ice cream mix in the containers of ice cream. Automatic controls connected to the measuring equipment adjust the regulator for the mix pump to change the amount of air mixed with the ice cream mix in response to measurements taken by the measuring equipment.

Abstract: When the difference between the weight proportional signal and the tare value is less than a predetermined threshold value, it is assumed that the zero point is changing. Main difference signals less than the threshold signal are stored and subsequently generated ones algebraically added to the first one. The so-created cumulative difference signal is compared to a predetermined limiting value. When it exceeds the limiting value the cumulative difference signal is divided by the number of differences which together created the cumulative difference signal. The so-formed average difference signal is added to the tare value prior to generation of the next main difference signal.

Abstract: Weighing apparatus for measuring loads and/or calculating the value of loads which includes a weighing device and an evaluating device. The weighing device is provided with a movement responding to the load being weighed and producing a corresponding electrical measurement signal, while the evaluating device translates the electrical measurement signal into a digital readout and also is capable of calculating the value of the load in accordance with a scheduled value for the load being weighed. An electrical cable connects the evaluating device with the weighing device for the purpose of transmitting electrical signals from the weighing device to the evaluating device. A data storage unit is permanently connected to the weighing device for storing constants that modify the output of the movement to compensate for errors inherent in the movement when it is manufactured.

Abstract: A vehicle with a vertically adjustable auxiliary axle and having its center of gravity located behind the auxiliary axle so that when said axle is moved down to a testing position where its wheels engage the ground, the front wheels of the vehicle are raised off the ground and the entire vehicle weight is supported by the rear wheels and the auxiliary wheels. When the auxiliary axle is in a testing position, the distance between the outer edges of the contact surfaces of the auxiliary and rear wheels is on the order of but not greater than 10 feet. The vehicle may be rolled over a scale platform while in the testing position so that a known weight is applied in an infinite number of 10 foot sections. The scale may be calibrated to accurately reflect the known weight under all different applications of that weight.

Abstract: This invention relates to an improved digital scale arrangement which employs apparatus for generating an electrical analog signal representing the weight on the scale mechanism. The analog signal is then converted to a digital representation of the weight on the scale under control of a microprocessor or microcomputer. The microcomputer then further processes the digital representation and causes it to be displayed. In accordance with the present invention, a fully automatically operating arrangement is provided for verifying the correct operation of the analog portion, the converting portion, and the digital portion of the arrangement. In addition, the arrangement is also employed to automatically correct the span of the scale under control of the results of the verification operation.

Abstract: To control the completeness of the content which is not fixed in a package, the package is brought in an inclined position. In the case of incomplete packing, the content slides in the package whereby the distribution of weight changes, which change is measured.For safety, the package can then be inclined in opposite direction, whereupon the distribution of weight is measured again and the two values obtained are compared.

Abstract: Control for a multiple batch process for preparing product from a plurality of constituent ingredients, in which an error in one batch from the multiple batch is equally divided over the subsequent batches so that all of the remaining portion of the multiple batch can be used and the resulting product is uniform. In the process of preparing product from a plurality of constituent ingredients, a batch of certain of such ingredients is mixed in a receptacle, sequentially divided into substantially equal portions and transported to an apparatus for combination with certain other of such ingredients for preparing the product. The error compensating control comprises an intermediate chamber in flow communication with the receptacle and the apparatus. A predetermined portion of the mixed batch is transferred from the receptacle to the intermediate chamber, where it is weighed, and then delivered to the apparatus.

Abstract: A combination weighing device for individually weighing a plurality of articles and selecting individual articles having a predetermined combined weight which includes an intended weight register, a plurality of weighing balances, an arithmetic unit for calculating the sum of the weights of selected articles and calculating the difference between the sum and the intended weight, a combination generator including switches for feeding predetermined combinations of article weights to said arithmetic unit, a comparator for determining the deviation of a combined weight with the intended weight for each combination of articles and a memory for recording the various computations so that the combination of article weights within prescribed limits and most nearly equal to the intended weight can be selected.

Abstract: Device to determine the weight of an object by moving the object at a predetermined velocity into a probe, a sensor associated with the probe to indicate the change in momentum to determine the weight.

Abstract: This relates to a load spring indicator for a railway car truck for indicating the load condition of springs supporting the bolster on the truck side frame. A reference is carried by the bolster and an indicator is carried by the truck side frame. The bolster reference is preferably the lower edge of the bolster gib or side rib while the indicator is an added plate or casting portion having an upper edge alignable with the lower edge of the bolster gib in the light condition of the car and a lower edge alignable with the bolster gib lower edge in the loaded condition of the car when the spring sets are of the proper strength and the car is not overloaded.

Abstract: In a scale wherein the signal signifying the weight is generated by counting of clock pulses over a weight-dependent part of a predetermined time interval, a second counter counts clock pulses in the remaining part of the predetermined time interval. These are added to the clock pulses counted during the weight-dependent part of the predetermined time interval and compared to a reference number which represents the total number of clock pulses in the predetermined time interval. An error signal is furnished if the two numbers do not correspond.

Abstract: This invention concerns a weighing device to measure the weight of a sample of powder supplied by a suitable feed-mechanism.This weighing device comprises at least one sample-holder vessel and a taring vessel, connected to a transfer mechanism which moves the sample-holder vessel from a filling position where it is directly under the feed-mechanism, to receive the sample, to an emptying position, and which also sets the taring vessel and the vessel containing the sample on a weighing mechanism in turn, to measure their weight.The invention concerns this weighing device and an installation comprising such a device, used in particular for volumetric analysis of a sample of powder, such as raw material for cement-making.

Abstract: The weighing apparatus is of the conveyor type and is supplied by a forwarding conveyor from which products are transferred, by a transfer conveyor to the weighing conveyor and from there to a discharge conveyor. The apparatus weighs only selected ones of the products arriving on the forwarding conveyor; and, for this purpose, comprises a support conveyor to support the selected articles while in transfer to prevent their coming into contact with the weighing conveyor.

Abstract: A high speed weighing machine, for determining the weight of a package "on-the-fly", with respect to a predetermined weight range, as the package travels across a weigh cell weighing platter, incorporates apparatus for interpreting multiple samplings of the weight bearing on the weighing platter for determining the interval during which the package is fully on this weighing platter and for calculating the average weight registered by the weighing platter during that interval wherein three periods are defined for each weighing operation.

Abstract: The method comprises the steps of sequentially taking containers filled in a multi-station filling machine, of weighing each of said taken containers, of comparing said weighing to a preset value for the filling devices of the filling machine and of establishing a correlation between each taken and weighed filled container and the corresponding filling station of the filling machine. In a filling machine comprising a rotation filling apparatus having n filling stations, the control device comprises at least a rotating transfer apparatus arranged in series with the rotating filling apparatus with interposition of at least an intermediary transfer wheel. The rotating transfer apparatus comprises n.sub.1 stations among which n.sub.1 -1 passive stations and a control weighing station provided with a balance, numbers n and n.sub.1 being incommensurable numbers.

Abstract: A dielectric tube, such as glass or plastic, having a square cross section extends between the two plates of a capacitance-sensing transducer. The opposite sides of the tube have a spacing only slightly greater than the diameter of the capsules to be checked. The capsules to be classified are oriented prior to their introduction into the tube so that they enter in an end-to-end relationship. The requisite spacing between the capsules is accomplished by an air jet device that rapidly accelerates the leading capsule as it enters the tube to such a velocity that it leaves the transducer before the next capsule enters, thereby assuring that only one capsule is in the transducer at any given moment. The capacitance-sensing transducer is repeatedly charged and discharged by means of a high frequency oscillator circuit.

Abstract: The present invention relates to a novel and improved apparatus for controlling or obtaining the actual weight of materials which are charged to a receptacle or other receiving means such as a shipping container. The present invention also resides in a novel apparatus for simultaneously determining the weight and moisture content of such materials.

Abstract: A method and apparatus are provided for controlling the minimum and average weights of a product prior to packaging so as to assure that no charges are below a given minimum weight and to assure that the average weight of the charges is maintained at a predetermined level over the entire operating period of the machine producing the charges. After weighing, any charges under the minimum weight are brought up to weight by adding product. The deviation of the final weight of the charges from the average is then determined and an indication provided of the amount and direction of each deviation. All of these indications of the deviation from the average are summed to produce a running tally representative of the total net deviation from the average. The production of charges is correctively controlled when the summation exceeds a preselected level in either direction. An alarm may be energized and the system shut down when a further higher level is exceeded.

Abstract: A scale with a digital computing device and a digital display, in particular for weighing bulk goods, in which the weighing result is determined as a mean value over a measuring cycle, comprising means for assessing the difference between the results of two consecutive measuring cycles, means for comparing this difference with a pre-determined value and means for controlling the length of the measuring cycles in function of this comparison.

Abstract: An improved scale, and particularly an electronic postage scale, wherein a parcel is weighed and postage is computed automatically in accordance with the weight of the parcel and the particular class of shipment and destination zone therefor. It is one feature of this scale to determine a corrected reference level against which the parcel is weighed, notwithstanding changes in this reference level over a period of time due to, for example, parameter changes, electrical "drift," a build-up of particles, such as dirt or other residue, or the like. Another feature of this scale is improved, simplified automatic calibration. The scale is provided with a keyboard which, during a calibration operation, is selectively operated so as to key-in numerical data representing a standard weight. The keyed-in data is compared to the standard weight as actually measured by the scale, and a calibration factor is generated by dividing the keyed-in data by the measured standard weight.

Abstract: A checkweigher uses a strain gauge load cell to provide a digital count which in turn is utilized to provide for automatic rezeroing and simplified referencing. The "grey zone" is taken into account for 100% rejection. Give away weight and standard deviation are also automatically determined.

Abstract: The total weight of fibrous material delivered to a packaging device, such as staple textile fiber delivered to a baling press, is controlled so as to facilitate achieving more uniform package weight in accordance with a method and through the use of an apparatus in which material is successively accumulated into batches, each of which is a fractional portion of a desired package weight. Batches are accumulated and released as the actual weight of each delivered batch is determined and registered and the registered actual weights of the successive batches are totaled. The weight of at least certain batches in the succession is then adjusted in such a manner as to closely control the total weight. A weigh container having an inlet and an outlet is interposed between and operatively communicates with a source of supply of fibrous material, such as a tow cutter, and a packaging device, such as a baling press. A load cell is provided which signals the weight of material supported by the weigh container.

Abstract: A machine for cutting up lumps of crude rubber (synthetic or natural) and weighing out an accurate quantity to be fed to a mixer in accordance with a selected formula, comprising two band saws having special blades with teeth having no "set" and lying entirely within the plane of the blades; crude rubber blocks are fed to a first of two band saws on two conveyor belts which pass one to either side thereof, one of the two conveyors being laterally displaceable and able to convey one of the portions into which the block of crude rubber is cut by the first band saw to be cut by the second band saw, the lateral position to which this portion is conveyed determining the relative size and therefore weight of the two pieces into which this portion is cut; all the cut portions and pieces are fed to an output conveyor which feeds them selectively to a hopper under the control of an automatic weighing machine.

Abstract: An improved method for automatically producing a selected weight draft of sliced product from a workpiece in substantially uniform weight slices and in an integral number of slices.

Abstract: Weighing apparatus is disclosed including an operating device for displacing a weighing beam arresting assembly to its arresting position, and for simultaneously effecting illumination of all of the segments of a multi-segment display device. In one embodiment, a manually operable rotatable shaft is provided having a pair of cams thereon for operating the beam arresting assembly and for operating a switch to cause illumination of all of the display segments, respectively. In a second embodiment, closing of a switch to effect illumination of all of the display segments is accompanied by the energization of a motor to displace the arresting assembly to its arresting position.

Abstract: An apparatus for the weighing of mass produced articles, especially highly-tempered glass products shortly after their formation, which are transferred with the interposing of a balancing device, by means of a weighing conveyor belt from a delivery conveyor belt on to a removal conveyor belt which runs at an angle to the delivery conveyor belt. The apparatus aids quality control by monitoring article weight. It operates dependably even in dirty, turbulent, high temperature environments.

Abstract: Disclosed herein is an automatically controlled weigh feeding apparatus including a container for prefilling with a substance, a device for discharging the substance from the container at a controllable rate, apparatus for weighing the substance being discharged and for producing an electrical signal proportional to that weight, a voltage to frequency converter connected to receive the electrical signals, a digital computer, apparatus coupled to an output of the voltage to frequency converter for inputting data signals to the digital computer, the computer being adapted to compute a corrective signal based on the input data signals received, and coupling apparatus coupled between the computer and the device for discharging the substance from the container for controlling the rate of discharge responsive to the corrective signal.

Abstract: Apparatus for controlling the weight of product charges fed to a receptacle, such as a weigh bucket associated, for example, with a packaging machine, in order to minimize product giveaway, is disclosed, wherein there is but a single receptacle to which the product is fed, and the product is check-weighed one or more times before being discharged from the receptacle. Flow of product to the receptacle is stopped when a predetermined feed cut-off weight is sensed by weighing means, and the product is then checkweighed. If the weight being sensed is less than the minimum package weight allowed or desired, one or more additional charges of product may be fed to the receptacle, and when the desired weight is reached, which may be equal to or above the minimum package weight, product is discharged. The additional charges of product fed to the receptacle after a checkweighing operation may comprise either a pulsed feed or a continuous feed until minimum package weight is reached.

Abstract: The invention discloses a weight sorting system wherein a single weighing station controls a plurality of weight-range article removal stations. These removal stations are disposed downstream of the weighing station and sorting information is synchronously passed with the articles on route to discharge. The rate at which articles are selected for removal at a given station is controlled by varying the weight range for that station. The weighing system is constantly re-calibrated by employing a plurality of test weights, one for each sorting weight range, carried by the conveyor system and an electronic compensating unit.

Abstract: Apparatus for controlling and adjusting the weight of doses of a loose product in a rotating metering head having telescoping volumetric members distributed therearound. The apparatus includes a rotating control head having a set of sample telescoping volumetric members. A main duct feeds the product to the metering head. A secondary duct is branched off the main duct to feed the control head. A scale is operative to receive individual sample doses as provided by the telescoping members of the control head and to discharge them, after the weighing thereof has been completed, to the metering head. A control assembly adjusts in a concurrent proportional mode the volume of the telescoping members of the metering and control heads according to the weight variations of the weighed product versus the scale reference value.

Abstract: In electronic measuring systems the accuracy of measurement is affected by drift not only of the zero but of the gain due to temperature changes, aging and supply conditions. The invention provides an automatic gain correction means so as to maintain an accurate relationship between the magnitude of the characteristic being measured and the value displayed or recorded. The measuring system is such that a train of pulses is counted over a predetermined time interval with a train of pulses representing, by its pulse repetition rate, the magnitude of the characteristic. A reference count is provided and means are provided for generating a pulse train simulating a predetermined magnitude of the characteristic being measured. Means are provided for counting the pulses of the generated pulse train and means are provided for comparing the reference count with the count of the generated pulse train to determine any error in the gain.

Abstract: A weighing system is described in which a weighing platform is operatively coupled to a transducer arrangement included in an electrical bridge circuit having connected therein a tare resistor arrangement for balancing out the tare weight of the platform. Means are provided for selectively isolating the effect of the tare resistor arrangement from the bridge circuit so that the system output indicates the sum of the tare weight of the platform and the weight of any load on the platform, thereby enabling the weighing system to be checked using the weight of the platform.

Abstract: In a container filling apparatus having a plurality of revolving charging cylinders and respective pistons by which a fluid material supplied into the cylinders with their pistons at the limit end of their intake strokes is subsequently pushed out of the cylinders to fill respective containers, an adjusting screw is provided to set by its one end the limit of the intake stroke of the piston rod of each piston and has a sprocket-like wheel fixed to its other end and actuated in incremental rotation by the piston rods of stationary air cylinders fixed to the apparatus frame when the wheel, revolving with its cylinder, is engaged by the piston rods. The activation of the air cylinders is controlled by electrical control means by which the limit of the intake stroke of any piston and, therefore, the filling quantity of the corresponding cylinder can be adjusted without danger and without stopping the operation of the apparatus.

Abstract: A method of and apparatus for determining and displaying the postal rate for a parcel to be shipped to a destination zone by a selected class of shipment in accordance with the weight of the parcel. A memory is provided with plural sections, each section being substantially associated with a particular class of shipment, and each section storing postal rate data for predetermined weight increments at addressable locations. The address of a location is determined by the parcel weight and the destination zone. Digital weight data is produced as a function of the weight of a parcel placed on the scale and the particular class of shipment and destination zone are selected as desired. The addressed memory location preferably is comprised of first and second parts for storing first and second portions of the composite postal rate data; these first and second parts being read out on a time sharing basis to a display device.

Abstract: A system for obtaining N slices of substantially uniform thickness from a solid to provide a batch having a desired weight, where N is an integer which may have a value between predefined limits. A partial batch weight is taken in response to weighing a number of slices less than N. A terminal value of N is estimated on the basis of the number of slices in the partial batch and the ratio of the desired batch weight and the partial batch weight. A predicted terminal deviation from the desired batch weight is calculated based on the partial batch weight and the ratio of the estimated value of N and the number of slices in the partial batch. In one embodiment the feed rate of the solid into a slicing device, and accordingly the slice thickness and terminal batch weight, is controlled as a function of the value of the predicted terminal deviation.

Abstract: A method of and device for feeding into the charging funnel of a worm machine strip-shaped or irregularly formed partial pieces of material, especially rubber, dosed by weight as components of a mixture, according to which the pieces are weighed individually and are conveyed to the worm machine in a cycle sequence time compensating for the difference of the rated value or preselected weight and the actual value of the weight of the individual piece. The device for practicing the method according to the invention has an electric scale preferably connected to an analog converter, which scale feeds a starting voltage proportional to the actual weight of the partial pieces to a rated value -- actual value comparator and to an electric calculator which latter determines the change in the cycle sequence time in conformity with the deviation from the preselected weight of the respective partial piece.

Abstract: An analog electrical system utilizes a signal from a coke weighing system and a signal from a coke moisture gauge to correct for prior errors in hopper weighings due to delivery overshoot as well as moisture variations in prior batches of coke.

Abstract: A scale position compensation means for a conveyor belt material transport system, the system including a conveyor belt having a tail end and a discharge end, belt drive means, and a weight signal generating means. Belt travel signal generating means produce a belt travel signal representing the change of belt position. The weight signal generating means produce a first digital weight signal representing a weight of material associated with a portion of the belt adjacent to a first reference point located between the tail and discharge ends. The scale position compensation means are responsive to the first digital weight signal and the belt travel signal to produce a second digital weight signal representing a weight of material associated with the above-mentioned portion of the belt when it is adjacent to a second reference point located between the first reference point and the discharge end.