US 3731286 A
An analog signal representing a continuously measured value is distributed to a plurality of capacitors, by a cyclic closing of a first set of contacts. The signal stored on the capacitors are read out by cyclic closing of another set of contacts which connect the capacitors to a receiver station. Each value of analog signal is delayed by the time interval between the storing in the capacitor and the read out from the same capacitor which occurs during the same cycle.
Description (OCR text may contain errors)
United States Patent 91 Graalmann et al.
[ 1 May 1, 1973  ANALOG SIGNAL DELAY ARRANGEMENT  Inventors: Gerhard Graalmann, Wohltorf;
Dieter Wellach, Hamburg, both of,
Germany  Assignee: Hauni-Werke Korber & Co. K.G.,
Hamburg, Germany  Filed: June 25, 1970  Appl. No.: 49,718
[ 30] Foreign Application Priority Data June 28, 1969 Germany ..P 19 32 906.7
 U.S. Cl. ..340/173 RC, 333/29, 333/30, 320/1,131/21  Int. Cl ..Gllc ll/24, G110 27/00  Field of Search ..340/173 RC; 333/29,
333/30; 320/1; 131/21 A, 21 B, 21 R, 22 A, 22 R; 335/114, 206
 References Cited UNITED STATES PATENTS 3,579,703 5/1971 Schmermund ..131/21 R 3,162,738 12/1964 Abramson et al. ..335/206 3,412,856 11/1968 Esenwein ..131/21 R 2,999,914 9/1961 Stanaway.. .....335/206 3,060,291 10/1962 Clare ..335/206 3,375,812 4/1968 Koda ..335/206 3,172,036 3/1965 Waters ..320/l X 3,441,913 4/1969 Pastoriza ..340/173 RC 3,192,402 6/1965 Sandberg... ..333/29 X 3,142,822 7/1964 Martin ..340/173 3,074,048 1/1963 Turner... ..340/173 RC 2,966,641 12/1960 McCoy ..340/l73 RC X 3,191,158 6/1965 Sherman ..'..320/1 X Primary Examiner-Malcolm A. Morrison Assistant Examiner-James F. Gottman Attorney-Michael S. Striker 57 ABSTRACT An analog signal representing a continuously measured value is distributed to a plurality of capacitors, by a cyclic closing of a first set of contacts. The signal stored on the capacitors are read out by cyclic closing of another set of contacts which connect the capacitors to a receiver station. Each value of analog" signal is delayed by the time interval between the storing in the capacitor and the read out from the same capacitor which occurs during the same cycle.
10 Claims, 2 Drawing Figures Patented May 1, 1973 3,731,286
2 Sheets-Sheet 1 /N VE N TORi) ww a! MQA.
Patented May 1, 1973 2 Sheets-Sheet GYM g jl' 44 46.4
ANALOG SIGNAL DELAY ARRANGEMENT BACKGROUND OF THE INVENTION This invention relates to a delay arrangement for delaying an analog signal between signal furnishing means and a receiver. In particular, it relates to such a delay arrangement when used in a tobacco processing machine.
In tobacco processing arrangements the problem often exists that a signal is furnished for controlling a process at a time prior to the time it should actually be applied for controlling said process. Thus the problem arises of delaying, or storing, an analog signal for a sufficient time and without excessive distortion until it is required in the processing arrangement.
An analog signal can be furnished by signal furnishing means which may, for example, be measuring means for measuring a given quantity or alternatively may be means for furnishing a desired value of a specified quantity. In special cases, such a signal may also be entered manually.
The receiver means, which receive the analog signal after the delay time, may be receiver means for receiving such a measurement signal or desired signal, and may be connected with a control arrangement which, under the control of the analog signal, controls a part of the tobacco processing.
Several examples of this type of problem when associated with tobacco processing arrangements will now be discussed.
If a given quantity of tobacco is, for example, to be combined with additives such as moisture or casing or flavoring liquid, it is particularly important in determining the quality of the tobacco that a predetermined ratio is maintained between the quantity of tobacco and the quantity of additive. The mixing process may take place at a mixing station. However, the weight of tobacco furnished to the mixing station will not, in general, remain constant. This requires a corresponding variation in the weight of additive to be supplied. Furthermore, the time that the tobacco travels from the place where it is, for example, weighed to the mixing station differs from the time required for a controlled amount of liquid additive to reach said mixing station. Generally, the time required for the tobacco to reach the station is considerably longer. Thus, the signal indicating the varying weight of tobacco must be delayed when this signal is applied to the control of the amount of liquid additive to be used at the mixing station.
The same problem arises when two or more streams of tobacco are to be mixed in such a way that a predetermined relationship exists in the various properties of the streams, such as weight and moisture. In arrangements for effecting such mixing, the individual streams of tobacco are measured and the analog signal corresponding to one of the measured values is used as a control signal for the other streams. That is, the analog signals representing the measured values of the other tobacco streams are compared to the corresponding analog signal representing the stream to be used as a standard. The difference signals resulting from these comparisons are then used to control processing elements at processing stations for the various streams. However, the processing stations are often at a distance from the measurement stations and it is therefore required that the various difference signals be delayed prior to application to the processing elements and that this delay take place without excessive distortion of said signals.
The same problem also arises when tobacco is to be dried. In this case, the heat supplied by a heating source is controlled in dependence on the varying amount of tobacco and/or the moisture content in said tobacco. Here again, a time difference is present between the time the weight of the tobacco or its moisture content is determined, and the time at which the heat source is to be controlled. Again, an analog signal must be stored for a corresponding delay time.
Generally, RC elements are used as time delay elements. However, these elements are not used' for furnishing long delay times becuase the capacitors do not maintain their charge for arbitrary time periods. Furthermore these elements are not adapted to hold analog values, for example in the form of a time varying voltage without considerable distortion.
Another possibility for delaying analog signals is to enter such signals upon a tape and to read out from this tape at a later time. This arrangement has the disadvantage that very costly equipment is required.
SUMMARY OF THE INVENTION It is an object of this invention to store an analog signal in a simple and inexpensive manner for arbitrarily long-time periods without causing excessive distortion.
This invention is an analog signal delay arrangement comprising signal furnishing means which furnish an analog signal. It further comprises a plurality of storage elements each for storing the instantaneous value of an analog signal applied thereto. Further furnished are receiver means. Cyclic transmission means transmit the .analog signal from the signal furnishing means to each of said storage elements in a predetermined sequence, thereby creating a stored signal in each of said storage elements. The cyclic transmission means further transmit the stored signals to the receiver means, each of said stored signals being transmitted to the receiver means at a predetermined time delay following the storing of the signals. Thus the analog signals are actually divided into a plurality of instantaneous values, each of these instantaneous values being stored in a storage element. The instantaneous values are then read out from the storage element within the same cycle of the cyclic transmission means, but after a delay time. In particular, the-storage in the individual elements and the read out from said storage elements may be controlled by an activating means which operates cyclicly and allows simultaneous storing in one element and read out from another storage element. This cyclic activating element thereby controls the frequency with which signals are read into storage, signals are read from storage, and the time delay between storage and read out.
The time delay required of course depends upon the consturction and the operating speed of the tobacco processing arrangement. Therefore the cyclic activating means should operate synchronously with the operation of the tobacco processing arrangement. For example, the cyclic transmission means may comprise a plurality of first contacts, each of said first contacts connecting said signal furnishing means to one of said storage elements when activated. It may further comprise a plurality of second contacts, each of said second contacts connecting said receiver means to oneof said storage elements. Finally, cyclic activating means activate each of said first and second connecting means. If each of the first and second connecting means is a pair of contacts in a Reed relay, then the cyclic activating element may be a rotating element carrying a permanent magnet. The permanent magnet causes closing of the contacts when in the operative vicinity thereof. In this arrangement, contacts are protected against dust, and no contact wear results from the interaction of the rotating elements and the contacts constituting the transmission means.
For special cases where it is desired to keep the number of moving parts to a minimum, an electronic circuit may be used as cyclic activating means. For example, a shift register may be used.
Since the analog signal requires amplification both before storage and during read out, due in part to the energy loss arising at the contacts, an operational amplifier is furnished between the signal furnishing means and the storage means and also between the storage elements and the receiver means. Since the transmission into the storage elements should be effected rapidly, while read out from the storage elements should take place without excessive power loss, the operational amplifiers have high input impedances and low output impedances.
Since the analog signal furnished by the signal furnishing means may undergo rapid variations within a storage interval and these rapid variations may lead to a distortion of the stored value, averaging means may be connected to the operational amplifier means in order to smooth the instantaneous values of the signals.
Mechanical, pneumatic or electrical components may be used as storage elements. Electrical elements as, for example, magnetic cores are particularly suitable because of their simple construction and relatively short response time. Capacitors may also be used.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the'accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows an arrangement for delaying an analog signal using electromechanical circuit activating means; and
FIG. 2 shows an arrangement for delaying an analog signal using an electronic circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will now be discussed with reference to the drawing.-
In FIG. 1, the signal furnishing means are denoted by reference number 38, while the receiver means comprise a power amplifier 22 in conjunction with a motor 17 driving a pump 16. The pump pumps an additive such as a casing liquid to be mixed with the tobacco in a mixing station 2. Tobacco 43 is supplied by a tobacco supply arrangement 3 which comprises a conveyor belt 4, an inclined conveyor 6 with smoothing 7 from which the tobacco moves to a conveyor-weighing roller mechanism 8 and a further conveyor belt 9. The drum 11 wherein the mixing is carried out, conveyor belt 9 and the conveyor belt of the weighing arrangement 8 I are all driven by means of a common drive 12. A conveyor belt 13 serves to remove the tobacco after treatment, that is after mixing with the additive. The container 18 contains the liquid casing or flavoring and is connected to a pump 16 by means of a line 19. The liquid is pumped to a spray arrangement 14 via a pipe 21. Pump 16 is driven by a variable speed motor 17. The mixing arrangement for the tobacco and the liquid is denoted by 44.
The plurality of storage elements in the embodiment of FIG. 1 is a plurality of capacitors denoted by reference numerals 23a through 23f. Cyclic transmission means, 1, comprise a plurality of first connecting means, namely contact pairs labelled 24a through 24f which, when activated, (closed) each connect the signal furnishing means 38 to one of the storage elements 23a through 23f. The second connecting means, namely contact pairs 26a through 26f serve to connect each storage element with the receiver means when activated. A switching element which rotates in the direction of the arrow 28 is denoted by reference numeral 27. This element rotates about an axis 29 and comprises an arm 31 on which is mounted a permanent magnet 32. Line 31 indicates that the rotating switching element 27 is driven by drive 12 via gearing 34. Rotation of arm 27 causes sequential closure of contact pairs 24:: through 24f and 26a through 26f. It is seen that in the present arrangement one of the pairs of contacts 24 is always activated substantially simultaneously with one of the pairs of contacts 26. Thus a signal is stored and the value of a previously stored signal is read out substantially simultaneously. The rotational speed of arm 31 determines the frequency with which signals are stored, the frequency with which signals are read out, as well as the delay time between storing and read out.
Between signal furnishing means 38, which furnish an analog signal corresponding to the weight of tobacco passing over the conveyor weighing arrangement 8, and the storage element is connected on operational amplifier 36 whichhas a high input impedance denoted by h and a low output impedance denoted by n. Similarly, additional operational amplifier means, namely operational amplifier 37, is connected between the storage elements and the receiver means. The second operational amplifier also has a high input impedance and a low output impedance. Power amplifier 22 serves not only for power amplification, but also to determine the speed of motor 17. Lines 39 and 41 connect contacts 24 .and 26, respectively, with the operational amplifiers 36 and 37. Lines 42a through 42f connect contacts 24 through 26 with copacitors 23.
The above-described arrangement operates as follows:
The tobacco is fed into the arrangement via conveyor belt 4 and transported via the inclined conveyor belt 6 in the direction of the arrow. Rollers 7 serve to equalize roughly the quantity of tobacco being transported. The tobacco 43 then reaches the conveyorweighing arrangement 8 where it is weighed and at which time an analog electrical signal corresponding to the weight of the tobacco is furnished by signal furnishing means 38. The tobacco then arrives at a conveyor belt 9 which conveys it to the drum 11. Pump 16 pumps liquid from container 18 and pushes it through line 21 into the spraying arrangement 14. There the liquid is sprayed onto the tobacco at the mixing stage 44. After treatment, tobacco 43 moves onto conveyor belt 13 for the further processing. In order that a good quality of tobacco, for example in cigarettes, may be obtained, the percentage relationship between the liquid additive and the tobacco 43 is to be exactly maintained. This can only be achieved if the supply of liquid is constantly regulated in accordance with the weight of the tobacco. However, the tobacco is weighed not at the mixing station, but at a station preceding said mixing station. Therefore a time delay exists between the furnishing of the measurement signal and the arrival of the tobacoo 43 at the mixing station 44. This time delay may vary in each installation. The liquid of course travels in a relatively short time period from the container 18 to the mixing stage 44. Thus the analog signal representing the measurement value must be delayed by a time interval corresponding to the time required for the tobacco to move from stage 8 to stage 44 minus the time required for the liquid to be pumped through line 21. This is achieved as follows: The analog signal furnished by signal furnishing means 38 is applied to operational amplifier 36. The operational amplifier 36 has, as stated above, a high input impedance. The output of operational amplifier 36, which is a low impedance output, is connected via line 41 to contacts 24a through 24f. Switching element 27 is driven in the direction of the arrow by means of drive 12 via gearing 34. The time required for one operating cycle, that is one complete rotation of switching element 27, corresponds to the time required for tobacco 43 to move from weighing stage 8 to the mixing stage 44 decreased by the amount required to pump the liquid through pipe 21.
Each of the contacts 24 and 26 is operated in sequence during each operating cycle for a short time period. In the position shown in the Figure, contacts 24a and 26a are being activated by permanent magnet 32 and are therefore closed. Thus, the output it of operational amplifier 36 is connected via contact 24a with condenser 2311. Since the output of the operational amplifier 36 is a low impedance output, the capacitor is charged to the correct value almost without delay. Thus, while the permanent magnet 32 passes the contacts, the measurement value is stored in capacitor 23a. Simultaneously, contact 26a is closed, therefore capacitor 23fis connected to the high impedance input h of operational amplifier 37 via this pair of contacts 260. Thus in the same time in which a signal is stored in capacitor 23a, a signal is read out from capacitor 23f. This signal read out is the same signal which was stored at the beginning of the time delay period. This signal is applied to the high impedance input h of amplifier 37. Almost no power is required because of the high impedance. The output of operational amplifier 37 is furnished to power amplifier 22 without distortion and without time delay because of the low impedance output n. Power amplifier 22 amplifies the signal and adjusts the speed of motor 17 as a function thereof. Thus the amount of liquid being pumped by pump 6 is varied in dependence upon the signal furnished by operational amplifier 37. It is thus adjusted to correspond to the amount of tobacco weighed at the beginning of the delay time interval and is thus in direct correspondence to the amount of tobacco being mixed at the time the signal is received at amplifier 22. Further turning of arm 31 causes a short overlapping of the closing times of contacts 26a and 24f. This overlap serves to prevent interruption of the signal at the input of amplifier 22 and removes the necessity for averaging or filtering elements between contacts 26 and operational amplifier 37.
FIG. 2 shows a second embodiment of the present invention. The main difference between the arrangement of FIG. 2 and that of FIG. 1, is that in FIG. 2 the cyclic activating means comprise an electronic circuit. The tobacco processing arrangement which may be identical to that of FIG. 1 is omitted in FIG. 2. Otherwise those components in FIG. 2 which correspond to components in FIG. 1, have the same reference numbers but increased by 100.
The cyclic activating means in FIG. 2 are a shift register 161 which has stages 1620 through 162i. A magnet 163a through 163i is connected to each shift register stage. Contacts 164a through 164i and 166a through 166i are each associated with one of the capacitors 167a through 167i which serve as storage elements. The contacts are activated by magnets 163a through 163i. The mixing arrangement which is not shown is driven by a drive 112. This drive motor 112 also drives pulse furnishing means 156 as indicated by line 154.
The pulse furnishing means 156 comprise a cam disk 157 which rotates synchronously with motor 112. Cams 168 induce pulses in a coil 158 which are shaped by a pulse former 159 which may, for example, be a monostable multivibrator.
A switch 152 which has contacts a and b connected to one side of a current source 151 serves to activate relay 153, thus in turn energizing motor 112. Closing of switch 152 also serves to energize shift register 161.
The input h of an operational amplifier 137 can be connected with capacitors 167a through 167i via contacts 164a through 164i. A power amplifier 122 is connected to the output n of operational amplifier 137. Amplifier 122 also serves to determine the speed of motor 117 which activates a pump for pumping liquid additive. Operational amplifier 136 has connected to it averaging means, namely a capacitor 171 in parallel with a resistance 172. The parallel combination of capacitor 171 and resistance 172 is connected from the output of amplifier 136 to its input. The output of signal furnishing means 138 is connected to the input h of operational amplifier 136. The output it of operational amplifier 136 can be connected with capacitors 1670 through 167i via contacts 166a through 166i.
This arrangement operates as follows: Switch 152 energizes relay 133 and thus driving motor 112 which operates the tobacco processing arrangement. Simultaneously, the shift register 161 is activated via contact a of switch 152. Cam disk 157 is driven synchronously with drive motor 112, causing cams 168 to induce pulses in coil 158 during rotation of said disk. These pulses are applied to pulse former 159 and there transformed, for example, into rectangular pulses. The pulse repetition rate at the output of pulse former 159 is the same as the repetition rate of the pulses applied to the pulse former. These vpulses are applied to the individual stages 162a through 162i of shift register 161 cuasing a pulse to be shifted through to this register at a rate determined by the repetition rate of the so-applied pulses. The time required for a pulse to travel through all the stages of shift register 161 corresponds to the time required for the tobacco to travel from the measuring station 138 to the mixing station 44 (FIG. 1 decreased by the time required to pump the liquid from pump 117 to the mixing stage 44 of FIG. 1. Relays 16311 through 163i are activated synchronously and cause closing of contacts 164 and 166 in a corresponding sequence. Thus while the analog signal furnished by signal furnishing means 138 is applied to a capacitor 167 via operational amplifier 136 and one of the contacts 166, the value stored in capacitor 167 is transmitted via contact 164 to the high impedance input of operational amplifier 137 and causes the output of power amplifier 122 to vary the speed of motor 117, and thus the quan tity of liquid pumped in accordance with the quantity of tobacco currently arriving at the mixing station.
The averaging means 169, comprising a capacitor 171 in parallel with a resistance 172, are connected from the output to the input of operational amplifier 136. This causes short time variations in the measurement signal which may lead to a distortion of the stored measuring value to be smoothed.
The above description indicates that shift register 161 in this case controls both the time delay and the frequency of signal storage and signal read out.
The particular advantage of the present invention consists of the simple construction of the transmission and storage arrangement, By dividing the analog signal into a predetermined plurality of individual values, it is possible to store analog signals for relatively long time periods and thus to delay said analog signals. A further advantage of the present invention is that an arbitrary number of storage elements may be used. Thus, the individual values of the analog signal may follow so closely one upon the other that upon read out, a true representation without distortion of the initial analog signal results. 7.
While the invention has been illustrated and described as embodied in electromechanical electronic transmission arrangements, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. Analog signal delay arrangement, comprising, in combination, signal furnishing means for furnishing an analog signal; first operational amplifier means connected to said signal furnishing means, said first operational amplifier means having a high input impedance and a low output impedance; averaging means connected to said first operational amplifier means; a plurality of storage elements each for storing the instantaneous value of an analog signal applied thereto; additional operational amplifier means having a high input impedance and a low output impedance; receiver means connected to said additional operational amplifier means; a plurality of first normally open pairs of contacts each connecting one of said storage elements to said first operational amplifier means when closed; a plurality of second normally open pairs of contacts each connecting one of said storage elements to the input of said additional amplifier means when closed; and cyclic activating means having an operating cycle, for closing each of said first and second pairs of contacts in a predetermined sequence within each of said operating cycles in such a manner that each of said first pairs of contacts is activated substantially simultaneously with a corresponding one of said second pairs of contacts and in such a manner that each of said second pairs of contacts is closed prior to the termination of the closure of the preceding second pair of contacts in said predetermined sequence, thereby furnishing a substantially uninterrupted signal to said receiver means.
2. Signal delay arrangement as set forth in claim 1, wherein said operational amplifier means comprise an operational amplifier having an input and an output; and wherein said averaging means comprise a feedback resistor, a feedback capacitor connected in parallel with said feedback resistor and connected from said output to said input of said operational amplifier.
3. Signal delay arrangement as set forth in claim 1, wherein said pairs of contacts are pairs of reed relay contacts; and wherein said rotating switching element comprises a permanent magnet for activating said contacts.
4; An arrangement for processing tobacco at a processing station in dependence with the weight of tobacco at said processing station, comprising, in combination, transport means transporting said tobacco along a predetermined path to said processing station; control means at said processing station for adding quantities of additives to said tobacco, said quantities of additives varying as a function of the amplitude of a control signal; measuring means located at a measuring station along said predetermined path preceding said processing station in the direction of transport of said tobacco, for continually measuring the quantity of tobacco transported per unit time and furnishing measurement signals having amplitudes corresponding to said so-measured quantity of tobacco; electric signal furnishing the means for converting said measurement signals into elecJric signals; a plurality of storage elements for storing the instantaneous value of an electrical signal applied thereto; and cyclic transmission means operating in synchronization with said transport means for transmitting said electrical signal from said signal furnishing means in a predetermined sequence to each of said storage elements, thereby creating a stored signal in each of said storage elements, and for transmitting each of said stored signals to said control means after a predetermined time delay following the creation of said stored signal, said so-transmitted stored signal constituting said control signal.
5. Signal delay arrangement as set forth in claim 4, further comprising operational amplifier means connected between said signal furnishing means and said storage elements.
6. Signal delay arrangement as set forth in claim 5, further comprising additional operational amplifier means connected between said storage elements and said control means; and wherein said operational amplifier means'and said additional operational amplifier means each have a high input impedance and a low output impedance.
7. Signal delay arrangement as set forth in claim 4, further comprising additional operational amplifier means connected between said storage elements and said control means.
8. Signal delay arrangement as set forth in claim 4,
wherein said cyclic activating means comprise an electronic circuit.
9. Signal delay arrangement as set forth in claim 8, wherein said electronic circuit is a shift register.
10. Signal delay arrangement as set forth in claim 4, wherein each of said storage elements comprise a capacitor.