SYSTEM AND METHOD FOR WEIGHING DOUGH PORTIONS BEFORE PROOFING

Abstract

An apparatus and method for automatically weighing dough pieces from the rounding conveyor, dynamically weighing the dough pieces. The weight information is analyzed by a weighing mechanism which can include a weigh conveyor or other means for weighing to determine whether it represents the weight of pieces or the empty weight, and may be used to provide a signal proportional to the weight of a dough portion, or group of dough portions in order to automatically adjust the rate at which dough is fed to the dividing mechanism, thereby increasing or decreasing the dough piece weights to maintain the desired amount of dough per piece.

Claims

1. An apparatus for producing a plurality of portions of semi-solid matter, each portion having a substantially uniform preselected target weight, comprising: a feed mechanism that has an operating rate that is controlled by inputting a control signal; a dividing mechanism configured to receive a continuous flow of the semi-solid matter from the feed mechanism and to divide the semi-solid matter into portions sized in proportion to the operating rate of the feed mechanism; a rounding conveyor downstream from said dividing mechanism configured to receive and transport the portions as the portions are released from the dividing mechanism; a weigh conveyor having a tare weight downstream from said rounding conveyor, the weigh conveyor having a load cell configured for producing indications representative of the weight of a portion resting on the weigh conveyor; a processor in electrical communication with the feed mechanism and the load cell, the processor programmed to: send the operating rate control signal to the feed mechanism, receive a group of a predetermined number of successive weight indications from the load cell, calculate the average weight indication of the group, determine whether all of the weight indications in the group fall within a predetermined standard deviation of the average weight indication of the group, and if so, calculate the difference between the average weight and the sum of the target weight and the tare weight of the weigh conveyor; and if the difference is less than a predetermined tare set point, to use the average weight as the tare weight for subsequent weight indications; and if the difference is greater than the predetermined tare set point, to include the average weight indication of the group in an array of a predetermined number of weight samples, calculate the average of the weight samples in the array, and adjust the operating rate control signal according to the difference between the average sample weight and the sum of the target weight and the tare weight of the weigh conveyor.

2. The apparatus of claim 1 wherein the weigh conveyor is configured to accommodate multiple portions, and the predetermined number of successive weight indications received from the load cell is selected to encompass a time period less than the interval between loadings of successive portions into the weigh conveyor.

3. The apparatus of claim 2 wherein the predetermined number of successive weight indications received from the load cell is selected to encompass a time period less than the interval between the loading and unloading of a single portion.

4. The apparatus of claim 2 wherein the predetermined number of successive weight indications received from the load cell is selected to encompass a time period less than the interval between the unloading of a single portion and the loading of the next successive portion.

5. The apparatus of claim 1 wherein the load cell comprises a force restoration electro magnetic mechanism.

6. The apparatus of claim 1 further comprising a guiding mechanism wherein the guiding mechanism funnels each dough piece to its respective weigh conveyor for orderly transportation to a proofer gate while being weighed.

7. A method of providing a dough proofing system for continuously dividing a mass of semisolid matter into a plurality of portions, each portion having a preselected target weight, comprising the steps of: providing a device that feeds a mass of semi-solid matter to a dividing mechanism and has an operating rate that is controlled by inputting an operating rate control signal; providing the dividing mechanism that divides the matter into portions; providing a rounding conveyor configured to receive and transport the portions from the dividing mechanism; providing a proofer downstream from the conveyor configured to receive and transport the portions of semi-solid matter from the rounding conveyor; providing a weigh conveyor to transport the portions of semi-solid matter from the rounding conveyor to the proofer; providing a load cell to support the weigh conveyor that provides an indication of the weight of the portions of semi-solid matter on the weigh conveyor; providing a processor in electrical communication with the device that feeds the semi-solid matter to the dividing mechanism and the load cell, the processor programmed to: obtain a group of a predetermined number of successive weight indications from the load cell; calculate the average weight indication of the group; determine whether all of the weight indications in the group fall within a predetermined standard deviation of the average weight indication of the group, and if so, calculating the difference between the average weight and the sum of the target weight and the tare weight of the empty weigh bucket; and if the difference is less than a predetermined tare set point, use the average weight as the tare weight for subsequent weight indications; and if the difference is greater than the predetermined tare set point, including the average weight indication of the group in an array of a predetermined number of weight samples, calculate the average of the weight samples in the array, and adjust the operating rate control signal according to the difference between the average sample weight and the sum of the target weight and the tare weight.

8. The method of claim 7 wherein the operating rate control signal corresponds to a numerical value, and the device that feeds the mass of semi-solid matter to the dividing mechanism has an upper operating rate corresponding to an upper operating rate control signal, at which rate portions having maximum weight are divided, and a lower operating rate corresponding to a lower operating rate control signal, at which rate minimum weight portions are divided; and the step of adjusting the operating rate control signal according to the difference between the average weight and the sum of the target weight and the tare weight comprises adjusting the numerical value of the operating rate control signal by an amount equal to the difference between the numerical value of the upper operating rate control signal and the numerical value of the lower operating rate control signal, multiplied by the (sum of the target weight and the tare weight less the average weight), multiplied by a predetermined moderating factor.

9. The method of claim 8 wherein the predetermined moderating factor is the reciprocal of the target weight.

10. The method of claim 8 wherein the predetermined number of successive weight indications received from the load cell is selected to encompass a time period less than the interval between the loading and unloading of a single portion in the weigh bucket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention will now be further described in conjunction with the drawings, in which:

[0010] FIG. 1 is a diagram illustrating the system and method of one embodiment of the present invention with a typical arrangement of dough processing equipment in a commercial bakery for buns, rolls, or muffins; and

[0011] FIG. 2A and FIG. 2B is a flow chart diagram illustrating the method of one embodiment of the present invention.

[0012] These drawings are provided for illustrative purposes only and should not be used to unduly limit the scope of the Invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] As shown in FIG. 1, one embodiment of the present invention comprises a dough production mechanism 10, a dough feed mechanism 12, a dividing mechanism 14, a weighing mechanism 16, and a weight signal processor 18 to calculate and transmit appropriate control signals to the dough feed mechanism 12. FIG. 1 illustrates a typical dividing mechanism 14 that is capable of cutting dough pieces at very high production rates. Once portioned, the dough pieces fall to a rounder conveyor 22 that shapes the dough pieces into spheres and delivers them to a flouring area, where the dough pieces may be floured by a flouring mechanism 26 prior to delivery to a weigh conveyors 24.

[0014] The weigh conveyors 24 are configured to receive the dough portions from the rounding conveyor 22 from where the rounded dough balls are guided to their respective weighing conveyors 24. The weighing conveyors 24 are preferably servo driven allowing dough balls to be delivered to a downstream proofer 20 precisely as the proofer gate 32 indexes the next group of dough balls into the proofer 20. The embodiment can include a dough ball guiding and flouring mechanism wherein the mechanism guides the dough piece through a flouring stream from flouring device 26 to the weigh conveyors 24. The weigh conveyors 24 then calculates the required speed to arrive at the proofer indexing gate 32 at the right time for smooth transitioning. As the dough pieces are conveyed by the weigh conveyors 24, the precise weighment is made for each dough balls net weight. The speed of the weigh conveyors 24 and weigh time is variable to accommodate the range of production speeds.

[0015] After passing through the indexing gate 32, the dough pieces are then loaded into the proofer trays on proofer 20. The dough pieces are allowed to rest as they are conveyed through the proofer 20. As the dough pieces are discharged from the proofer 20, they are conveyed to a molder 28 and fed into baking pans on a pan indexing conveyor 30.

[0016] The apparatus can transport a complete proofer tray of dough pieces to the proofer 20, weighing each dough piece individually dynamically as it travels across the weigh conveyors 24. Preferably, the entire dough piece population is weighed for weight sampling. A corrective signal is sent to the feed mechanism 12 from the weight signal processor 18 to continuously produce constant weight portions of dough, whereby variations in the weight of each portion are minimized by automatically adjusting the rate at which the dough is fed to the dividing mechanism.

[0017] The weighing mechanism may consist of weigh conveyors 24 attached to a high precision load cell 16 that causes the dough portions to be transported in an orderly fashion to the proofer feed gate 32. The dough portions travel forward into the process stream without interruption before molding.

[0018] The method can include inputting an initial operating rate control signal into the dividing mechanism 14 or use an optimum saved control signal derived from prior production data of a given variety to the feed device. The initial tare weight includes any flour or particulate to an allowable maximum tare weight. The method can include dividing portions of semi-solid matter from the mass using the dividing mechanism 14, obtaining a group of a predetermined number of successive weight indications from the load cell 16, and calculating the average weight indication of the group. The method can include determining whether all of the weight indications in the group fall within a predetermined standard deviation of the average weight indication of the group, and if so, calculating the difference between the average weight and the sum of the target weight and the tare weight of the weigh conveyor.

[0019] The weight data is processed by an algorithm running on the weight signal processor 18. In the algorithm, the weights of samples are placed into an array of selectable size. These sample weights enter and exit the array first-in first-out order. The standard deviation of the data in the array is recalculated when each new sample weight is processed.

[0020] As the dough portion falls from the dough ball guide to the weigh conveyors 24, the weigh conveyors 24 supported by a load cell 16, which provides an indication of the displacement of a resilient counterforce due to the weight of the portion. Various types of counterforces, such as springs or elastomeric materials, can be used in the load cell 16. The displacement of the counterforce can be measured most readily by devices which exhibit varying electrical properties under physical deformation or displacement, such as strain gages, transducers or forced motor. The analog electrical indications generated by the load cell can be converted by an analog to digital converter ('A/D) to a digital signal compatible for input to the weight signal processor. The load cell 16 used with the weigh conveyors 24 may utilize a load cell body or counter force that is submerged in an engineered high density fluid to provide impact cushioning and limit the post impact oscillation (ringing) of the counter force due to the impact of the dough portion on the weigh conveyors 24.

[0021] The weight signal processor 18 converts the electrical indications generated by the load cell 16 at a sampling rate of up to 1,000 weight samples per second, and uses a computer algorithm to place these sample weight indications in to an array of selectable size for statistical analysis as is known to those skilled in the art.

[0022] The array size is preferably selected to encompass weight indications taken during a timeframe that is less than the interval during which a single portion is at rest on the weighing conveyors 24 at production rates, so that the weight indications can be statistically analyzed to determine an accurate portion weight. Also, because an accurate net portion weight is dependent upon subtraction of an accurate weight of the empty load cell (tare weight) from the total load cell reading, the array size is also preferably selected to encompass a series of weight indications taken during a timeframe that is also less than the interval between the time a portion is fully removed from the load cell and the time the next portion is first deposited in contact with the load cell, so that the weight indications of the empty load cell during production conditions can be statistically analyzed to determine an accurate tare weight.

[0023] Because production rates can be in the range of 180 portions per minute or more, the cycle time for loading and unloading a single portion is one third of a second. Accordingly, the array size for the fully loaded and unloaded time intervals within that cycle will be on the order of 0.1 seconds, or approximately 100 samples each. These intervals represent the time while the single dough portion is at rest on the load cell or alternatively when there is no dough portion on the load cell. The algorithm is thus devised to identify arrays of sequential sample indications which fall within a predetermined standard deviation of the average weight indication of the array. By rejecting arrays having erratic weight indications outside of the standard deviation, only the arrays which do not include weight indications taken while the dough portion is either being placed on the load cell or removed from the load cell will be used to determine the tare weight and the net portion weight and to control the portion size produced by the dividing mechanism or means for dividing. This algorithm eliminates data samples which do not provide valid indications of the load cell with the dough portion in place or alternatively the unloaded load cell.

[0024] These samples enter and exit the array first-in, first-out (FIFO) order. The standard deviation of the data in the array is recalculated upon the entry of every new sample. When the standard deviation of the weight samples is within the predetermined level, indicating that the array represents data taken during the time that a single or multiple dough portions are at rest on the conveyor or alternatively when there is no dough portion on the weigh conveyors 24, an averaged weight is calculated using the array data. If the calculated average weight indication is above the predetermined tare set point, it is determined to be near the prior calculated individual dough piece weight plus the prior calculated tare weight, and a new individual dough piece weight is calculated using the new average individual dough piece weight minus the current calculated tare weight. Alternatively, if the calculated average weight indication is below the predetermined tare set point, it is determined to be near the prior calculated tare weight, and the new calculated average weight indication is used as the new tare weight. When the standard deviation of the weight samples exceed the predetermined level, the weight data in the array includes readings taken when the weigh conveyor or other means for weighing is either loading or unloading a dough piece and is not used. This process is repeated for successive array data to compile a sample group of dough portion weights which can be averaged and filtered and compared to the desired portion weight.

[0025] If the difference between the average weight and the sum of the target weight and the tare weight of the weigh conveyor is greater than a predetermined tare set point, the method can include adjusting the control signal according to the difference between the average weight and the sum of the target weight and the tare weight. In other embodiments, if the difference is greater than the predetermined tare set point, the method can involve including the average weight indication in an array of a predetermined number of weight samples, and calculating the average of the weight samples in the array, and adjusting the control signal according to the difference between the average sample weight and the sum of the target weight and the tare weight. If the difference is less than the predetermined tare set point, the method can include using the average weight as the tare weight for subsequent weight indications.

[0026] In one embodiment, the weight sampling is the entire population, with 100 dough piece portions providing 100 weight samples per minute. This weight sample information is calculated in comparison to the desired dough piece target weight. A corrective signal is sent from the weight signal processor 18 to the feed mechanism 12 to continuously produce constant weight portions of dough, whereby variations in the weight of each portion are minimized by automatically adjusting the rate at which the dough is fed to the dividing mechanism 14. Adjustments to the portion size can thus be made by varying the control input to the servo-controlled dough feed mechanism 12.

[0027] In some embodiments, the weight signal processor 18 is programmed to receive a group of a predetermined number of successive weight indications from the load cell 16, calculate the average weight indication of the group, determine whether all of the weight indications in the group fall within a predetermined standard deviation of the average weight indication of the group, and if so, calculate the difference between the average weight and the sum of the target weight and the tare of the empty means for weighing; and if the difference is less than a predetermined tare set point, to use the average weight as the tare weight for subsequent weight indications; and if the difference is greater than the predetermined tare set point, to include the average weight indication of the group in an array of a predetermined number of weight samples, calculate the average of the weight samples in the array, and adjust the control signal according to the difference between the average sample weight and the sum of the target weight and the tare weight.

[0028] FIG. 2A and FIG. 2B is a flow chart diagram illustrating the method of one embodiment of the present invention. As shown in FIG. 2A and FIG. 2B, at step 100, the tare set point, desired array size, and the predetermined standard deviation are input.

[0029] At step 120, if the new weight sample along with the prior weight samples input are sufficient in number to complete the array, the process proceeds to step 130. If the sample count data points in the array is not sufficient to complete the array, the process reverts to step 110 for input of additional weight sample data.

[0030] If the array was previously full, as each new weight sample data is added, the oldest prior weight sample data entry is deleted from the array.

[0031] At step 130, the average and standard deviation of the data in the array are calculated. At step 140, if the standard deviation is less than the predetermined standard deviation limit, the process continues to step 150. If the standard deviation exceeds the predetermined limit, the process reverts to step 110 for the input of additional weight sample data until the data in the array is sufficiently consistent to meet the standard deviation limitation.

[0032] At step 150, the average of the array weight samples is compared to the predetermined tare set point. If the average weight is less than the tare set point, the array comprises weight sample data from the unloaded load cell, and is used to update the tare weight variable at step 160. This updated tare weight variable is subsequently used to calculate the net weight of the dough portions. Upon completion of this updating of the tare weight variable, the process reverts to step 110 for the input of additional weight sample data.

[0033] Alternatively, if the average weight of the array data is greater than the tare set point, the data represents load cell indications taken while a dough portion is at rest on the load cell, and the tare weight variable is subtracted from this average load cell reading to calculate the dough piece net weight at step 170. This dough piece net weight data is also included in the dough piece sample set at step 170.

[0034] The dough piece sample group is of a user selected size, normally comprising a group of 8 to 12 dough piece weights. This group of weights is averaged and compared to the desired dough piece weight to determine if a corrective signal is required.

[0035] As shown in step 180, if the number of dough piece sample data points is less than the predetermined number of dough piece samples in the group, the process reverts back to step 110 for the input of further data. Alternatively, if the dough piece sample group size is sufficient, at step 190 the average of the dough piece weight data in the dough sample group is calculated.

[0036] Various methods of filtering the data in the dough sample group may be used. For example, as illustrated in step 200, any weight sample data varying more than 1% from the average dough piece weight can be eliminated from the dough sample group, and then the average dough piece weight to is recalculated using the more restrictive sample group data, to provide an average which is unaffected by erratic sample weight data. Other methods to filter data include eliminating the two data points in each sample group having the greatest deviation from the average dough piece weight data and to then recalculate the average dough piece weight using the more restrictive sample group data.

[0037] As shown in step 210, if the average weight of the dough pieces in the filtered sample group is greater than the target weight, at step 220, a corrective signal proportional to the deviation from the target weight is sent to the dividing mechanism to reduce the size of the dough piece. After the corrective signal is sent to the dividing mechanism, the process reverts back to step 110.

[0038] Conversely if the average weight of the dough pieces is not greater than the target portion weight, at step 230 if the average of the sample group is less than the desired portion weight, at step 240, a corrective signal proportional to the deviation from the target weight is sent to the dividing mechanism to increase the size of the dough piece. After the corrective signal is sent to the dividing mechanism, the process reverts back to step 110.

[0039] If the sample group average weight is equal to the target weight, no corrective signal is sent to the dividing mechanism, and the process reverts to step 110.

[0040] In one embodiment, the present invention comprises a mechanism that produces semi-solid dough, a dividing mechanism that divides the semi-solid matter into portions and a device that feeds the semi-solid matter to the dividing mechanism and has an operating rate that is controlled by inputting a control signal. The control signal corresponds to a numerical value, and the feed device has an upper operating rate corresponding to an upper operating rate control signal, at which rate portions having maximum weight are divided, and a lower operating rate corresponding to a lower operating rate control signal, at which rate minimum weight portions are divided. The step of adjusting the control signal according to the difference between the average weight and the sum of the target weight and the tare weight comprises adjusting the numerical value of the operating rate control signal by an amount equal to the difference between the numerical value of the upper operating rate control signal and the numerical value of the lower operating rate control signal, multiplied by the (sum of the target weight and the tare weight less the average weight), multiplied by a predetermined moderating factor. The predetermined moderating factor is preferably the reciprocal of the target weight, or some fractional part of the reciprocal of the target weight.

[0041] Thus, in one embodiment, the present invention comprises a method of providing a dough proofing system for continuously dividing a mass of semisolid matter into a plurality of portions, each portion having a preselected target weight, including the steps of: providing a device that feeds a mass of semi-solid matter to a dividing mechanism and has an operating rate that is controlled by inputting an operating rate control signal; providing the dividing mechanism that divides the matter into portions; providing a conveyor configured to receive and transport the portions from the dividing mechanism; providing a proofer downstream from the conveyor configured to receive and transport the portions of semi-solid matter from the conveyor to a weigh bucket; providing a load cell to support the weigh bucket that provides an indication of the weight of the empty weigh bucket and the weight of the dough portions inside the weigh bucket; providing a processor in electrical communication with the device that feeds the semi-solid matter to the dividing mechanism and the load cell. In some embodiments, the method can include providing a tipper for tipping the proofer to deliver the matter in the proofer to the weigh bucket, or mechanism for weighing.

[0042] In another embodiment, the present invention includes a method of continuously dividing a mass of semisolid matter into a plurality of portions, each portion having a preselected target weight, comprising the steps of: feeding a mass of semi-solid matter to a dividing mechanism, or means for dividing, with a feed rate that is controlled by inputting an operating rate control signal; dividing the mass of semi-solid matter into portions using the dividing mechanism, or means for dividing; transporting the portions from the dividing mechanism, or means for dividing, on a conveyor; receiving the portions from the conveyor on a proofer, or means for proofing, downstream from the conveyor configured to transport the portions from the conveyor to a weigh bucket, or means for weighing; measuring the weight of the empty weigh bucket, or means for weighing, and the weight of the portions inside the weigh bucket, or means for weighing, using a load cell that supports the weigh bucket, or means for weighing; inputting the operating rate control signal to the device that feeds the semi-solid matter to the dividing mechanism, or mans for feeding; inputting an initial tare weight for the weigh bucket, or means for weighing; obtaining a group of predetermined number of successive weight indications from the load cell; calculating the average weight indication of the group; determining whether all of the weight indications in the group fall within a predetermined standard deviation of the average weight indication of the group, and if so, calculating the difference between the average weight and the sum of the target weight and the tare weight of the empty weigh bucket, or means for weighing; and if the difference is less than a predetermined tare set point, using the average weight as the tare weight for subsequent weight indications; and if the difference is greater than the predetermined tare set point, including the average weight indication of the group in an array of a predetermined number of weight samples, calculating the average of the weight samples in the array, and adjusting the operating rate control signal according to the difference between the average sample weight and the sum of the target weight and the tare weight.

[0043] In another embodiment, the present invention comprises a method of providing a dough proofing system continuously dividing a mass of semisolid matter into a plurality of portions, each portion having a preselected target weigh, including the steps of: providing a means for feeding a semi-solid matter to a means for dividing at a rate which varies in response to an operating rate control signal; providing a means for dividing that divides the matter into portions; providing a conveyor configured to receive and transport the portions from the means for dividing; providing a means for proofing downstream from the conveyor configured to receive and transport the portions of semi-solid matter from the conveyor to a means for weighing; providing a load cell to support the means for weighing that provides an indication of the weight of the empty means for weighing and the weight of the portions in the means for weighing; providing a processor in electrical communication with the means for feeding and the load cell.

[0044] The method of one embodiment of the present invention can be utilized with multiple weigh buckets or means for weighing to accommodate a proofer designed for multiple lanes of dough piece processing. The support structure can be made wide enough for multiple weigh buckets in one or more lanes of dough piece processing.

[0045] Although the subject invention has been described in use primarily with respect to dough, the invention is applicable to many other production processes involving controlled weight portions of semi-solid matter, including but not limited to agricultural and food products, polymers, plastics, resins, cellulose, gelatins, refractory products, ceramics and the like. Many changes, modifications, variations, combinations, sub combinations and other uses and applications of the subject invention will be and become apparent to those skilled in the art after considering this specification and the accompanying drawings, which disclose a preferred embodiment thereof. All such changes, modifications, variations, and other uses and applications that do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.