CA1180084A - Controlling and indicating device for a milking machine - Google Patents
Controlling and indicating device for a milking machineInfo
- Publication number
- CA1180084A CA1180084A CA000390349A CA390349A CA1180084A CA 1180084 A CA1180084 A CA 1180084A CA 000390349 A CA000390349 A CA 000390349A CA 390349 A CA390349 A CA 390349A CA 1180084 A CA1180084 A CA 1180084A
- Authority
- CA
- Canada
- Prior art keywords
- milk
- tube
- coil
- control apparatus
- pulsator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01J—MANUFACTURE OF DAIRY PRODUCTS
- A01J5/00—Milking machines or devices
- A01J5/007—Monitoring milking processes; Control or regulation of milking machines
- A01J5/01—Milkmeters; Milk flow sensing devices
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01J—MANUFACTURE OF DAIRY PRODUCTS
- A01J7/00—Accessories for milking machines or devices
- A01J7/005—Automatic vacuum shutoff at the end of milking
Abstract
ABSTRACT OF THE DISCLOSURE
A CONTROLLING AND INDICATING
DEVICE FOR A MILKING MACHINE
Milk flow sensor consisting of a coil surrounding a dielectric milk flow conduit in communication with a milking teat cup and of sufficiently large dimensions to ensure pulsating milk flow therethrough a high frequency oscillating signal input to the coil and an electronic circuit for comparing the resultant changing amplitude output signal therefrom to a reference voltage representative of minimum milk flow.
A CONTROLLING AND INDICATING
DEVICE FOR A MILKING MACHINE
Milk flow sensor consisting of a coil surrounding a dielectric milk flow conduit in communication with a milking teat cup and of sufficiently large dimensions to ensure pulsating milk flow therethrough a high frequency oscillating signal input to the coil and an electronic circuit for comparing the resultant changing amplitude output signal therefrom to a reference voltage representative of minimum milk flow.
Description
The invention relates to the control of a suction milking machine, more especially to a device designed to terminate the suction operation of the teat cups upon cessation of milk flow from the udder.
The device is further designed to indicate, either optically or acoustically, whether the stoppage of the milk flow is due to an empty udder or due to external causes.
It is a well kno~n fact that a milking machine must stop the pu~sations in the teat cups as soon as the milk starts to flow out of the teats in a trickle only, a sign that the udder is empty. Further milking will cause irritation of the teat with subsequent inflammation which may lead to infection of the udder and to general diseases. This problem has been tackled in many ways, and nowadays all but the most primitive machines are equipped with automaic stopping devices which are monitored by the cessation of the full stream of milk from the udder to the container and its replacement by a thin trickle. The known devices are, wi-th~ut e~ception, built on the principle of a chamber containing a float, electrodes or other means for monitoring the pulsator acting on the teat cups, this chamber is positioned in the line between the teat cups and the collecting vessel and is provided in its bottom portion with an outlet nozzle of a very small diameter, and with a main outflow opening of a large diameter a few centimeters above this nozzle~ As long as a full stream of milk passes through this chamber the liquid level therein is sufficiently high so that the major part of the milk leaves the chamber through its high-positioned main outflow opening, and only a small part through thenarrow nozzle. The high liquid level acts on the monitoring means in a manner so as to keep the pulsator in motion. As soon as the udder is nearly empty, milk flows out in a small batches and the liquid level in the chamber sinks, since now the narrow nozzle is sufficient to permit the passage of all the milk pumped out. This causes the float to sink or the electrodes to stop passing a current, ,.~, .
l~ V~
whereby the pulsator operation is stopped and the teat cups are automatically dropped off the udder, without the assis-tance of human hands.
Although these devices, in whate~er form they may be desig-nated, operate quite satisfactorily while new, they are soon clogged by fatty matter or mineral sediments contained in the milk and many failures have been experienced. Partly clogging will also cause wrong timing, i.e. later stopping of the pulsator than initially intended.
~ It is therefore an object of an aspect of the present invention to do away with control equipment dependent on throttling of the milk flow by a narrow nozæle and to provide a control device designed on a free flow of the milk through a wide pipe or tube. It is an object of an aspect lS of the invention to provide a device which will operate independently of sedimentation on the wall of this tube or pipe as well as independently of the fat contents of the milk.
~topping of the milking operation alone is, however, not advisable i~ the milk flow has stopped before the udder is empty; several reasons may be responsible for a premature stoppage, the most frequent being the accidental strip-ping of the teat cups from the udder, either due to a quick movement of the cow or to external causes. Another cause for premalure stoppage may be the holding-back by a frightened co~i; still another reason for early stopping may be reduced milk yield of the animal~ either due to a disease or to the end of the lactation period of a cow, i.e. 9-10 months after calving.
It should be noted that incomplete milking, leaving milk in the cow's udder, by accidental interruption o the operation, will cause pains and may cause inflammation as well as diminished milk yield. On the other hand, reduced milk yield requires either treating of the diseased animal or release of a cow into the pasture when she is at the end of lactation.
~oo~
In a milking parlour where a large number of cows are milk-ed simultaneously it is very important that the dairyman becomes immediately aware of the cause of the cessation of the milking operation, the more as the teat cups fall off the udder as soon as the suction operation stops, and as they are generally pulled up to the ceiling by a vacuum-operated lifting device, and there is no way of telling whether the cow is fully milked, whether she withholds the milk for on~ of the above reasons, or whether her lactation period is nearing its end.
For this reason it is an object of an aspect of the present invention to provide the control device with means for indi-cating, by optical or acoustical means, the different ~auses of the cessation of the milking operation: one kind of signal serving to indicate normal stopping, before the udder is sucked completely empty; ano:her kind of signal indicating that the teat cups were forcibly removed ~efore the actual end of the milking; and still another signal indicating that the milking operation was shorter than the minimum milking time of a healthy cow - which is about two minutes or more -, i.e. that the milk flow from the udder has stopped at an interval of less than two minutes after starting.
An aspect of this invention is as follows:
A control apparatus for a milking machine which latter is provided with teat cups operated by an electric pulsator, a milk collecting vessel kept at sub-pressure, a pipeline therehetween through which all of the milk from said teat cups flows to said vessel, comprising in combination a tube of a non-conductive material inserted into the pipe line connecting said teat cups to said milk collecting vessel, said pipe line and said tube being -;
of sufficiently wide dimensions to carry the milk as pulses of milk flowing in separated portions passing o~
-4a-through said line and said tube at the rate of the pulsator pulses, a coil of~wire windings surrounding said tube on its outside, an electronic system including means for applying a high-frequency voltage to said coil, means for detecting the varying amplitude high frequency output signal from said coil indicative of the varying conductivity of the coil interior space due to the milk passing therethrough in pulses, and means for comparing saicL output signal with a predetermined voltage corresponding to a permissible minimum flow o milk, the system being adapted to interrupt the operation of said electric pulsator, as soon as the output signal reaches the value of said predetermined voltage.
Figure l illustrates the arrangement of a controlling and indicating device in the piping of a conventional suction milki~g machine, and Figure 2 is a block diagram of an electronic circuit adapted to terminate the pulsator operation and to produce diiferent signals in accordance with the nature of the milking opera-tion's end.
Before describing the working of the control and indicating device according to the invention and to enable ull under-standing of its design, a short description of a conven-tional milking machine is being given in the following with the aid of Figure 1 of the accompanying schematic draw-ing. Herein two teats l, l' of an udder (out of four) are shown, each of which has a teat cup 2, 2' attached to it by subpressure maintained in the system by a central vacuum pump (not shown). Each teat cup comprises a solid cylin-drical housing and concentric therewith a cylindrical and resilient membrane which form an annular inflatable space 3,3' therebetween. The teat cups are connected, by means of flexible hoses 4, 4' and 5, to an electric pulsator 6 which causes pressure pulses in the annular spaces 3, 3' by alternately connecting them to a central line 14 which is kept at sub-pressu~e by the aforementioned vacuum pump~ and to the at-mosphere; hereby the me~branes are alternately pressedagainst the teat and released, the inner space of the teat cup being kept permanently at sub-pressure through the milk lines 7, 7' and 8, and through a closed milk collector vessel 8 connected to the central line 14 by a line 13.
The action simulates manual milking whereby the milk flows out of the udder through the teats into the teat cups and is sucked out from these through the milk lines into the collector vessel 8. The pulsator is usually built to connect simultaneously all four teats to the sub-pressure and then to the atmosphere, or it actuates alternately two cups on and two cups off. Suitable milking pulses vary from 25 to 120 per minute, a common average being 60 pulses per minute which would - in a 2/2 arrangement, pump 120 portions per minute. A control apparatus (ll~ according to the invention is shown to be inser-tedinto the milk line;
this will be described further on.
The milk travels through the milk line in portions at a rate determined by the pulsator frequency, interrupted by zero supply intervals. A maximum rate of 66 cm3~s would be an excellent yield for a cow. This maximum volume drops gradually to a minimum of 4.75 cm3/s when a milking process should be stopped to avoid damage to the udder.
~8~
- 5a -These pulsating flow conditions are being utilized in the control device according to the invention, by comparing the pulse intensity of the minimum portion - at which the pulsator is required to stop operating with the pulse inten~ity during normal milking opera-tion.
The controlling and indicating device for a conventional milking machine comprises a tube of a non-conducting material, such as glass or plastics, which is inserted into the piping conducting milk from the teat cups to a milk container, this tube being of a sufficiently large diameter so as to carry the milk in discreteJ separated portions as dictated by the rate i~
of the electric pulsator operatj~ng the teat cups. A coil of wire windings surrounds the tube and is connected to a radio frequency oscillator. The coil ou-tput varies in accordance with the change of conductivity in the tube caused by the milk portions passing therethrough and consists of pulses of wildly varying length and intensity depending on the irregular flow of milk through the tube in portions of various length and veloci-ty. This output is smoothed to a d-c voltage in an electronic circuit which comprises means for rectifying, amplifying, filtering, zero level clamping and demodulating the pulses, thus obtaining resultant voltage that is proportional to the milk flow at every moment. This voltage is compared, in a comparator unit, with a reference voltage which corresponds to a predetermined permissible minimum flow of milk, demanding cessation of the milking operation. As soon as the resultant voltage is equal or lower than the reference voltage, the comparator output serves to interrupt the operation of the electric pulsator and to produce a signal, warning the attendant of the end of the milking operation of the specific cow. Additional and optional electronic circuitry is adapted to produce three specific kinds of signals, each one indicating one of the three causes of stoppage of milk flow through the tube. These signals may be optical or acoustical, either in the form of continuous or interrupted light flashes or humming sounds, or the indication may be by three different coloured lamps, by three differently -tuned loudspeakers, or by visual display, all of these methods being known to the art.
Before entering into the nature of the indicating device, it is important to understand the various conditions of the milk flow in the milking machine at the end of the operation :-''`'''' ,: ,.
.
8~ 34 1. Sudden removal of the teat cups does not stop the passage of n~lk portions through the above tube at once, owing to the length of piping, but there will be always a few last portions passing through the tube moved by the suction pressure o:f the machine, before the pipe is completely empty. In contradistinction to the regular ending of the milking process wherein the size of the milk portions passing through the tube decreases gradually, the milk portions after acc;dental removal of the teat cups remain of the same large size until the end, when they stop coming at all. However, since ~he cow is a living organism, it may happen that, with a conventional milking machine working at a frequence of 120 pulsations per minute, milk portions -especially near the end of the operation - may p ass through the piping and through the indicating tube at greater intervals, even up to 10 seconds, and may then return to a shorter frequency.
The device is further designed to indicate, either optically or acoustically, whether the stoppage of the milk flow is due to an empty udder or due to external causes.
It is a well kno~n fact that a milking machine must stop the pu~sations in the teat cups as soon as the milk starts to flow out of the teats in a trickle only, a sign that the udder is empty. Further milking will cause irritation of the teat with subsequent inflammation which may lead to infection of the udder and to general diseases. This problem has been tackled in many ways, and nowadays all but the most primitive machines are equipped with automaic stopping devices which are monitored by the cessation of the full stream of milk from the udder to the container and its replacement by a thin trickle. The known devices are, wi-th~ut e~ception, built on the principle of a chamber containing a float, electrodes or other means for monitoring the pulsator acting on the teat cups, this chamber is positioned in the line between the teat cups and the collecting vessel and is provided in its bottom portion with an outlet nozzle of a very small diameter, and with a main outflow opening of a large diameter a few centimeters above this nozzle~ As long as a full stream of milk passes through this chamber the liquid level therein is sufficiently high so that the major part of the milk leaves the chamber through its high-positioned main outflow opening, and only a small part through thenarrow nozzle. The high liquid level acts on the monitoring means in a manner so as to keep the pulsator in motion. As soon as the udder is nearly empty, milk flows out in a small batches and the liquid level in the chamber sinks, since now the narrow nozzle is sufficient to permit the passage of all the milk pumped out. This causes the float to sink or the electrodes to stop passing a current, ,.~, .
l~ V~
whereby the pulsator operation is stopped and the teat cups are automatically dropped off the udder, without the assis-tance of human hands.
Although these devices, in whate~er form they may be desig-nated, operate quite satisfactorily while new, they are soon clogged by fatty matter or mineral sediments contained in the milk and many failures have been experienced. Partly clogging will also cause wrong timing, i.e. later stopping of the pulsator than initially intended.
~ It is therefore an object of an aspect of the present invention to do away with control equipment dependent on throttling of the milk flow by a narrow nozæle and to provide a control device designed on a free flow of the milk through a wide pipe or tube. It is an object of an aspect lS of the invention to provide a device which will operate independently of sedimentation on the wall of this tube or pipe as well as independently of the fat contents of the milk.
~topping of the milking operation alone is, however, not advisable i~ the milk flow has stopped before the udder is empty; several reasons may be responsible for a premature stoppage, the most frequent being the accidental strip-ping of the teat cups from the udder, either due to a quick movement of the cow or to external causes. Another cause for premalure stoppage may be the holding-back by a frightened co~i; still another reason for early stopping may be reduced milk yield of the animal~ either due to a disease or to the end of the lactation period of a cow, i.e. 9-10 months after calving.
It should be noted that incomplete milking, leaving milk in the cow's udder, by accidental interruption o the operation, will cause pains and may cause inflammation as well as diminished milk yield. On the other hand, reduced milk yield requires either treating of the diseased animal or release of a cow into the pasture when she is at the end of lactation.
~oo~
In a milking parlour where a large number of cows are milk-ed simultaneously it is very important that the dairyman becomes immediately aware of the cause of the cessation of the milking operation, the more as the teat cups fall off the udder as soon as the suction operation stops, and as they are generally pulled up to the ceiling by a vacuum-operated lifting device, and there is no way of telling whether the cow is fully milked, whether she withholds the milk for on~ of the above reasons, or whether her lactation period is nearing its end.
For this reason it is an object of an aspect of the present invention to provide the control device with means for indi-cating, by optical or acoustical means, the different ~auses of the cessation of the milking operation: one kind of signal serving to indicate normal stopping, before the udder is sucked completely empty; ano:her kind of signal indicating that the teat cups were forcibly removed ~efore the actual end of the milking; and still another signal indicating that the milking operation was shorter than the minimum milking time of a healthy cow - which is about two minutes or more -, i.e. that the milk flow from the udder has stopped at an interval of less than two minutes after starting.
An aspect of this invention is as follows:
A control apparatus for a milking machine which latter is provided with teat cups operated by an electric pulsator, a milk collecting vessel kept at sub-pressure, a pipeline therehetween through which all of the milk from said teat cups flows to said vessel, comprising in combination a tube of a non-conductive material inserted into the pipe line connecting said teat cups to said milk collecting vessel, said pipe line and said tube being -;
of sufficiently wide dimensions to carry the milk as pulses of milk flowing in separated portions passing o~
-4a-through said line and said tube at the rate of the pulsator pulses, a coil of~wire windings surrounding said tube on its outside, an electronic system including means for applying a high-frequency voltage to said coil, means for detecting the varying amplitude high frequency output signal from said coil indicative of the varying conductivity of the coil interior space due to the milk passing therethrough in pulses, and means for comparing saicL output signal with a predetermined voltage corresponding to a permissible minimum flow o milk, the system being adapted to interrupt the operation of said electric pulsator, as soon as the output signal reaches the value of said predetermined voltage.
Figure l illustrates the arrangement of a controlling and indicating device in the piping of a conventional suction milki~g machine, and Figure 2 is a block diagram of an electronic circuit adapted to terminate the pulsator operation and to produce diiferent signals in accordance with the nature of the milking opera-tion's end.
Before describing the working of the control and indicating device according to the invention and to enable ull under-standing of its design, a short description of a conven-tional milking machine is being given in the following with the aid of Figure 1 of the accompanying schematic draw-ing. Herein two teats l, l' of an udder (out of four) are shown, each of which has a teat cup 2, 2' attached to it by subpressure maintained in the system by a central vacuum pump (not shown). Each teat cup comprises a solid cylin-drical housing and concentric therewith a cylindrical and resilient membrane which form an annular inflatable space 3,3' therebetween. The teat cups are connected, by means of flexible hoses 4, 4' and 5, to an electric pulsator 6 which causes pressure pulses in the annular spaces 3, 3' by alternately connecting them to a central line 14 which is kept at sub-pressu~e by the aforementioned vacuum pump~ and to the at-mosphere; hereby the me~branes are alternately pressedagainst the teat and released, the inner space of the teat cup being kept permanently at sub-pressure through the milk lines 7, 7' and 8, and through a closed milk collector vessel 8 connected to the central line 14 by a line 13.
The action simulates manual milking whereby the milk flows out of the udder through the teats into the teat cups and is sucked out from these through the milk lines into the collector vessel 8. The pulsator is usually built to connect simultaneously all four teats to the sub-pressure and then to the atmosphere, or it actuates alternately two cups on and two cups off. Suitable milking pulses vary from 25 to 120 per minute, a common average being 60 pulses per minute which would - in a 2/2 arrangement, pump 120 portions per minute. A control apparatus (ll~ according to the invention is shown to be inser-tedinto the milk line;
this will be described further on.
The milk travels through the milk line in portions at a rate determined by the pulsator frequency, interrupted by zero supply intervals. A maximum rate of 66 cm3~s would be an excellent yield for a cow. This maximum volume drops gradually to a minimum of 4.75 cm3/s when a milking process should be stopped to avoid damage to the udder.
~8~
- 5a -These pulsating flow conditions are being utilized in the control device according to the invention, by comparing the pulse intensity of the minimum portion - at which the pulsator is required to stop operating with the pulse inten~ity during normal milking opera-tion.
The controlling and indicating device for a conventional milking machine comprises a tube of a non-conducting material, such as glass or plastics, which is inserted into the piping conducting milk from the teat cups to a milk container, this tube being of a sufficiently large diameter so as to carry the milk in discreteJ separated portions as dictated by the rate i~
of the electric pulsator operatj~ng the teat cups. A coil of wire windings surrounds the tube and is connected to a radio frequency oscillator. The coil ou-tput varies in accordance with the change of conductivity in the tube caused by the milk portions passing therethrough and consists of pulses of wildly varying length and intensity depending on the irregular flow of milk through the tube in portions of various length and veloci-ty. This output is smoothed to a d-c voltage in an electronic circuit which comprises means for rectifying, amplifying, filtering, zero level clamping and demodulating the pulses, thus obtaining resultant voltage that is proportional to the milk flow at every moment. This voltage is compared, in a comparator unit, with a reference voltage which corresponds to a predetermined permissible minimum flow of milk, demanding cessation of the milking operation. As soon as the resultant voltage is equal or lower than the reference voltage, the comparator output serves to interrupt the operation of the electric pulsator and to produce a signal, warning the attendant of the end of the milking operation of the specific cow. Additional and optional electronic circuitry is adapted to produce three specific kinds of signals, each one indicating one of the three causes of stoppage of milk flow through the tube. These signals may be optical or acoustical, either in the form of continuous or interrupted light flashes or humming sounds, or the indication may be by three different coloured lamps, by three differently -tuned loudspeakers, or by visual display, all of these methods being known to the art.
Before entering into the nature of the indicating device, it is important to understand the various conditions of the milk flow in the milking machine at the end of the operation :-''`'''' ,: ,.
.
8~ 34 1. Sudden removal of the teat cups does not stop the passage of n~lk portions through the above tube at once, owing to the length of piping, but there will be always a few last portions passing through the tube moved by the suction pressure o:f the machine, before the pipe is completely empty. In contradistinction to the regular ending of the milking process wherein the size of the milk portions passing through the tube decreases gradually, the milk portions after acc;dental removal of the teat cups remain of the same large size until the end, when they stop coming at all. However, since ~he cow is a living organism, it may happen that, with a conventional milking machine working at a frequence of 120 pulsations per minute, milk portions -especially near the end of the operation - may p ass through the piping and through the indicating tube at greater intervals, even up to 10 seconds, and may then return to a shorter frequency.
2. Normal milking of a healthy cow in lactation lasts ~or a minimum of two minutes; and in case the milking operation lasts for less than 2 minutes, this ls a sure sign that the cow is either at the end of her lactation period, or that she is diseased, or that she, for some reason or other, withholds her milk in her udder.
These facts are being employed to indicate either of the three causes for s toppage of the elec~ric pulsator; for the purpose of terminating the pulsator action and to indicate the cause of the end of the nilk ~low an operation and indicating circuit is provided which is adapted to be triggered either by the comparator output or by the pulses created in the coil by the passing milk portions. The operation circuit is preferably connected to the respecti~e input and output side of the comparator by ~wo parallel circuits, each circuit comprising a timer switch (hereinafter called "timer" for short~ which is set-to delay the inrpulses from reachin~
the operation circuit by a pre~etermined interval. The two timers are interconnected, and the first timer to reach the end of its set time ,.~
~ . .
'' ~
interval triggers the operation circuit to the efect of stopping the pulsator action, however each timer produces a diferent visual or acoustical sign with a view to in~orm the-attendant o-f the normal course, or of a sudden interruption, of the milking operation. The circuit connecting the operation circuit to the comparator OlltpUt is provided with a timer A which is set to an interval slightly longer than the interval of a second timer tB) in the parallel circuit. A second comparator ~II) s~pplied with a low reerence ~oltage, is provided in the circuit connecting the operation circuit to the input side of the main comparator (hereinater called Comparator I) and p ermits only pulse of a certain magnitude to reach the timer B and to reset it every time, i.e. at the pulsator frequency. This timer B transmits a pulse to the operation circuit only after having run through its complete set interval which is preferably 14 seconds, i.e. a~ter the mîlk flow has practically stopped reaching the tube.
Both timers, A and B, are set to a longer interval than ten seconds, preerably between 14 and 16 seconds, to make allowance or the last, widely spaced milk portions arrivingj the interval of the timer A being a few s econds longer than that of timer B. A third timer ~C) is placed in a circuit connecting the output o timer A with the operation circuit. This timer is set to an interval of less than two minutes and is adapted to issue a signal to the operation circuit to the efect that the milking operation was stopped at a shorter time than normal.
The operation circuit is furthermore adapted to trigger rinsing and/or desin~ecting operations o the milk passages.
~le operation of the device is as follows: With normal ending o the milking operation, i.e. with the milk flow decreasing gradually, time A
is reset as soon as the comparator output starts, timer B having been constantly reset by the pulses right rom the beginning of the operation.
~q~ , This timer (B) is adapted to be reset only by a pulse of a predetermined intensity, as determined by the abovementioned comparator II which is fed a much lower reference voltage than comparator I; therefore, with decreasing milk flow, this timer (B) will be reset a few times by the last pulses passing through the tube. It will, accordingly, stop later than timer A which will transmit -the comparator output pulse to the operation circuit after 16 seconds, with the result that the pulsator action is stopped and, simultaneously, a visual or optical sign is given, indicating a NORMAL run.
In the case that the milking operation was stopped shor-t off the minimum time of 2 minutes, the same signal is transmitted to the operation circuit by -timer A, but at the same time the timer C
received an impulse from this timer (A) before having r~m through - 15 its interval. The timer C, in its turn, is adapted -to produce a signal to the operation circuit to the effect that it gives a SHORT
sign instead of the NO~MAL sign.
.
The third possibility that the tea-t cups have been inadvertently removed, will reset the timer B which will continue to receive strong pulses by the large milk portions still passing through the tube, since these were moving along the piping at the moment the cups fell off. ~ith the rest of the milk passing through the tlibe both timers, A and B, will be reset at the same moment and since timer A has a longer interval than timer B, the latter will be the first to actuate the operation circuit, causing the pulsator to be stopped c~nd a sign "OFF"' to be produced, warning the at-tendant.
L8~8~
:
- lQ
With reference -to Figure 1 of the drawing which has been partly described in the foregoing, the con-trol device consists of a tube 9 of a non-conductive material such as glass or a plastic material which is inserted into the piping conducting milk from the teat cups to a container and is surrounded by coil windings 10 of an insulated wire. A R-F oscillator connected to the coil terminals applies thereto a voltage of high frequency. The milk flowing in pulses through the tube and the coil interior causes a pulsating change of conductivity therein, which results in a varying coil induction and an output wave of changing amplitude as a function of the milk portlons passing through.
This signal is passed through an electronic analysing system and is compared with a standard pre-selected voltage which corresponds to the permissible mimimum milk flow. As soon as this minimum value is reachecl an output signal stops the pulsator 6 through an electric line 16 and prc~uces a warning light 15.
~The dimensions of the tuke and coil as well as the frequency may vary over a large range, but an apparatus built to the following dimensions has proved itself satisfactory in all respects. The tube was made of "Perspex" and had an inner diameter of 16 mm and a length of 250 mm. The coil wound around the outer tube diameter of 19.8 mm had a lenc~th of 85 mm, about 75 windings of a 1.0 mm wire. m e oscillator fre~uency was between 1 and 7 MHz.
Nevertheless, taking into account available space and electric conditions, it is proposed that the coil may have as little as 4 win~ings and a length of 5 mm or as many as 1000 windings at a length of 200 mm,while the ~8~
frequency may vary between 250 kHz and 20 ~lz. The minimum diameter o~
the tube may be 8 mrn and the maximum 40 mrn. ~le pulsator frequency may likewise vary between 25 and 120 milking pulses per minute.
Any non-conducting material that is not detrimental to milk may be used in the manufacture of ~he tube such as e.g. glass, provided it is wide enough to have the milk portions separated from each other, a continuous flow giving no signal at all.
Figure 2 shows an electronic circuit adapted to terminate tlle pulsator action and to procluce three different kinds of signals. l~e Figure shows the tube 9 of a non-conducting material surrounded by a wire coil 10.
A radio frequency oscillator is connected to the coil, and the resulting changing pulses are rectified, amplified, filtered and demodulated, before being fed into a comparator ~ which issues a signal as 500n as the input voltage reaches the value of the reference voltage. The signal is fed into an output and operation circuit through a timer A which is set, in the present case~ to an interval of 16 seconds, and produces a NO~lAL signal.
A second timer B, set to a shorter interval (14 seconds) is triggered by pulses before the comparator I, the connection being via a second comparator II which is supplied with~a reference voltage of low ma~nitude, preventing the timer to be triggered by very weak pulses. The timer B is likewise connected to the output and operation circuit~ besides of feeding its output into timer A and into a third ~imer C. Likewise the output of timer A is fed into timer B. The timer C is set *o an interval of about 100 seconds and its output ~ed into the operation circuit. This circuit is provided with three lamps (in the present case) only one lamp each being lighted at the end of the milking operation dependent on the action of the difEerent timers. The circuit further operates a switch 20 when actuated by either timer ~ or B. Another operation circuit causes rinsing and/or disinfecting of the milking machine to be initiated after the end oE the milking process.
, .
- , The operation of the circuitry will be described again lYith reerence to Figure 2: rne timer B is reset by each pulse issued by the zero level clanper, since its interval is much larger than the pulsator freqllency, however the timer C runs off after 100 seconds, if the milking operation lasts longer tilan that, i.e. is of normal length. As soon as the milk flow decreases below the stipulated minimum level, the timer A is actuated and runs down in 16 seconds~
The weak pulses Yhich have triggered the con~arator, are still strong enough to reset the timer B, as the reference voltage oi` its con~arator II is much lower than that of con~arator I. For this reason timer A will run down before timer B and will trigger the operation circuit, to the e~ect of stopping the pulsator action c~nd to light a "NORMAL" sign. In case the milk Elow has decreased below standard while the timer C is still running, it will receive a sic~nal fro~ the timer A, and will cause a lamp SHORT to be lighted, while the pulsator operation is being terminated as before.
However, in case the milking is suddenly interl~pted while the milk flow is still high, the timer B will be actuated by the last, large n~lk portions remaining in the long pipe line, and both timers will be reeet simultaneously when the last portion has passed through the tube. Now timer B will be the first to actuate the operation circuit, cut the pulsator action and give an "OFF" sign, denoting that the cups have dropped ofE by accident.
It is reiterated that any kind of signal can be given, either visual or acoustical, and that the circuitry may be changed, as long as the principle of the three timers is maintained.
The advantage of giving ready information to the dairyman is evident, and since all components of the electronic circuit are standard and commercially availableJ the cost of a device of this kind will be compensated in a very ç ~
, ~ , . ~, , ., , :
:- :
:: - .
, , Q~L
_ 13 s hort time by en~bling the personnel to attend in time to cows that require treatmellt or removal from the millcing parlour.
:
::
.~ .
.
, ,
These facts are being employed to indicate either of the three causes for s toppage of the elec~ric pulsator; for the purpose of terminating the pulsator action and to indicate the cause of the end of the nilk ~low an operation and indicating circuit is provided which is adapted to be triggered either by the comparator output or by the pulses created in the coil by the passing milk portions. The operation circuit is preferably connected to the respecti~e input and output side of the comparator by ~wo parallel circuits, each circuit comprising a timer switch (hereinafter called "timer" for short~ which is set-to delay the inrpulses from reachin~
the operation circuit by a pre~etermined interval. The two timers are interconnected, and the first timer to reach the end of its set time ,.~
~ . .
'' ~
interval triggers the operation circuit to the efect of stopping the pulsator action, however each timer produces a diferent visual or acoustical sign with a view to in~orm the-attendant o-f the normal course, or of a sudden interruption, of the milking operation. The circuit connecting the operation circuit to the comparator OlltpUt is provided with a timer A which is set to an interval slightly longer than the interval of a second timer tB) in the parallel circuit. A second comparator ~II) s~pplied with a low reerence ~oltage, is provided in the circuit connecting the operation circuit to the input side of the main comparator (hereinater called Comparator I) and p ermits only pulse of a certain magnitude to reach the timer B and to reset it every time, i.e. at the pulsator frequency. This timer B transmits a pulse to the operation circuit only after having run through its complete set interval which is preferably 14 seconds, i.e. a~ter the mîlk flow has practically stopped reaching the tube.
Both timers, A and B, are set to a longer interval than ten seconds, preerably between 14 and 16 seconds, to make allowance or the last, widely spaced milk portions arrivingj the interval of the timer A being a few s econds longer than that of timer B. A third timer ~C) is placed in a circuit connecting the output o timer A with the operation circuit. This timer is set to an interval of less than two minutes and is adapted to issue a signal to the operation circuit to the efect that the milking operation was stopped at a shorter time than normal.
The operation circuit is furthermore adapted to trigger rinsing and/or desin~ecting operations o the milk passages.
~le operation of the device is as follows: With normal ending o the milking operation, i.e. with the milk flow decreasing gradually, time A
is reset as soon as the comparator output starts, timer B having been constantly reset by the pulses right rom the beginning of the operation.
~q~ , This timer (B) is adapted to be reset only by a pulse of a predetermined intensity, as determined by the abovementioned comparator II which is fed a much lower reference voltage than comparator I; therefore, with decreasing milk flow, this timer (B) will be reset a few times by the last pulses passing through the tube. It will, accordingly, stop later than timer A which will transmit -the comparator output pulse to the operation circuit after 16 seconds, with the result that the pulsator action is stopped and, simultaneously, a visual or optical sign is given, indicating a NORMAL run.
In the case that the milking operation was stopped shor-t off the minimum time of 2 minutes, the same signal is transmitted to the operation circuit by -timer A, but at the same time the timer C
received an impulse from this timer (A) before having r~m through - 15 its interval. The timer C, in its turn, is adapted -to produce a signal to the operation circuit to the effect that it gives a SHORT
sign instead of the NO~MAL sign.
.
The third possibility that the tea-t cups have been inadvertently removed, will reset the timer B which will continue to receive strong pulses by the large milk portions still passing through the tube, since these were moving along the piping at the moment the cups fell off. ~ith the rest of the milk passing through the tlibe both timers, A and B, will be reset at the same moment and since timer A has a longer interval than timer B, the latter will be the first to actuate the operation circuit, causing the pulsator to be stopped c~nd a sign "OFF"' to be produced, warning the at-tendant.
L8~8~
:
- lQ
With reference -to Figure 1 of the drawing which has been partly described in the foregoing, the con-trol device consists of a tube 9 of a non-conductive material such as glass or a plastic material which is inserted into the piping conducting milk from the teat cups to a container and is surrounded by coil windings 10 of an insulated wire. A R-F oscillator connected to the coil terminals applies thereto a voltage of high frequency. The milk flowing in pulses through the tube and the coil interior causes a pulsating change of conductivity therein, which results in a varying coil induction and an output wave of changing amplitude as a function of the milk portlons passing through.
This signal is passed through an electronic analysing system and is compared with a standard pre-selected voltage which corresponds to the permissible mimimum milk flow. As soon as this minimum value is reachecl an output signal stops the pulsator 6 through an electric line 16 and prc~uces a warning light 15.
~The dimensions of the tuke and coil as well as the frequency may vary over a large range, but an apparatus built to the following dimensions has proved itself satisfactory in all respects. The tube was made of "Perspex" and had an inner diameter of 16 mm and a length of 250 mm. The coil wound around the outer tube diameter of 19.8 mm had a lenc~th of 85 mm, about 75 windings of a 1.0 mm wire. m e oscillator fre~uency was between 1 and 7 MHz.
Nevertheless, taking into account available space and electric conditions, it is proposed that the coil may have as little as 4 win~ings and a length of 5 mm or as many as 1000 windings at a length of 200 mm,while the ~8~
frequency may vary between 250 kHz and 20 ~lz. The minimum diameter o~
the tube may be 8 mrn and the maximum 40 mrn. ~le pulsator frequency may likewise vary between 25 and 120 milking pulses per minute.
Any non-conducting material that is not detrimental to milk may be used in the manufacture of ~he tube such as e.g. glass, provided it is wide enough to have the milk portions separated from each other, a continuous flow giving no signal at all.
Figure 2 shows an electronic circuit adapted to terminate tlle pulsator action and to procluce three different kinds of signals. l~e Figure shows the tube 9 of a non-conducting material surrounded by a wire coil 10.
A radio frequency oscillator is connected to the coil, and the resulting changing pulses are rectified, amplified, filtered and demodulated, before being fed into a comparator ~ which issues a signal as 500n as the input voltage reaches the value of the reference voltage. The signal is fed into an output and operation circuit through a timer A which is set, in the present case~ to an interval of 16 seconds, and produces a NO~lAL signal.
A second timer B, set to a shorter interval (14 seconds) is triggered by pulses before the comparator I, the connection being via a second comparator II which is supplied with~a reference voltage of low ma~nitude, preventing the timer to be triggered by very weak pulses. The timer B is likewise connected to the output and operation circuit~ besides of feeding its output into timer A and into a third ~imer C. Likewise the output of timer A is fed into timer B. The timer C is set *o an interval of about 100 seconds and its output ~ed into the operation circuit. This circuit is provided with three lamps (in the present case) only one lamp each being lighted at the end of the milking operation dependent on the action of the difEerent timers. The circuit further operates a switch 20 when actuated by either timer ~ or B. Another operation circuit causes rinsing and/or disinfecting of the milking machine to be initiated after the end oE the milking process.
, .
- , The operation of the circuitry will be described again lYith reerence to Figure 2: rne timer B is reset by each pulse issued by the zero level clanper, since its interval is much larger than the pulsator freqllency, however the timer C runs off after 100 seconds, if the milking operation lasts longer tilan that, i.e. is of normal length. As soon as the milk flow decreases below the stipulated minimum level, the timer A is actuated and runs down in 16 seconds~
The weak pulses Yhich have triggered the con~arator, are still strong enough to reset the timer B, as the reference voltage oi` its con~arator II is much lower than that of con~arator I. For this reason timer A will run down before timer B and will trigger the operation circuit, to the e~ect of stopping the pulsator action c~nd to light a "NORMAL" sign. In case the milk Elow has decreased below standard while the timer C is still running, it will receive a sic~nal fro~ the timer A, and will cause a lamp SHORT to be lighted, while the pulsator operation is being terminated as before.
However, in case the milking is suddenly interl~pted while the milk flow is still high, the timer B will be actuated by the last, large n~lk portions remaining in the long pipe line, and both timers will be reeet simultaneously when the last portion has passed through the tube. Now timer B will be the first to actuate the operation circuit, cut the pulsator action and give an "OFF" sign, denoting that the cups have dropped ofE by accident.
It is reiterated that any kind of signal can be given, either visual or acoustical, and that the circuitry may be changed, as long as the principle of the three timers is maintained.
The advantage of giving ready information to the dairyman is evident, and since all components of the electronic circuit are standard and commercially availableJ the cost of a device of this kind will be compensated in a very ç ~
, ~ , . ~, , ., , :
:- :
:: - .
, , Q~L
_ 13 s hort time by en~bling the personnel to attend in time to cows that require treatmellt or removal from the millcing parlour.
:
::
.~ .
.
, ,
Claims (7)
1. A control apparatus for a milking machine which latter is provided with teat cups operated by an electric pulsator, a milk collecting vessel kept at sub-pressure, a pipeline therebetween through which all of the milk from said teat cups flows to said vessel, comprising in combination a tube of a non-conductive material inserted into the pipe line connecting said teat cups to said milk collecting vessel, said pipe line and said tube being of sufficiently wide dimensions to carry the milk as pulses of milk flowing in separated portions passing through said line and said tube at the rate of the pulsator pulses, a coil of wire windings surrounding said tube on its outside, an electronic system including means for applying a high-frequency voltage to said coil, means for detecting the varying amplitude high frequency output signal from said coil indicative of the varying conductivity of the coil interior space due to the milk passing therethrough in pulses, and means for comparing said output signal with a predetermined voltage corresponding to a permissible minimum flow of milk, the system being adapted to interrupt the operation of said electric pulsator, as soon as the output signal reaches the value of said predetermined voltage.
2. A control apparatus as defined in claim 1, provided with a signal lamp which is adapted to light up upon inter-ruption of the pulsator operation.
3. A control apparatus as defined in claim 1, comprising a tube made of glass.
4. A control apparatus as defined in claim 1, com-prising a tube made of a plastic material.
5. A control apparatus as defined in claim 1, wherein the frequency used is approximately 5 mHz.
6. A control apparatus as defined in claim 5, wherein the coil comprises approximately 90 windings of a 0.67 mm wire, has a length of 100 mm and an inner diameter of 19.8 mm.
7. A control apparatus as defined in claim 1, wherein the frequency used is in the range 250 kHz-20mHz.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IL61516A IL61516A (en) | 1978-08-15 | 1980-11-19 | Controlling and indicating device for a milking machine |
| IL61516 | 1980-11-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1180084A true CA1180084A (en) | 1984-12-27 |
Family
ID=11052223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000390349A Expired CA1180084A (en) | 1980-11-19 | 1981-11-18 | Controlling and indicating device for a milking machine |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU550268B2 (en) |
| CA (1) | CA1180084A (en) |
| DE (1) | DE3145888A1 (en) |
| FR (1) | FR2494084A1 (en) |
| GB (1) | GB2090431B (en) |
| NL (1) | NL8105230A (en) |
| ZA (1) | ZA817526B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1272156A (en) * | 1985-11-01 | 1990-07-31 | Maltec, Llc | Optical milk flow detector and vacuum shutoff for milker |
| DE59002343D1 (en) * | 1990-01-19 | 1993-09-16 | Latvijskaja Sel Skochozjajstve | DEVICE FOR DETERMINING THE MILKING PERFORMANCE OF A MILKING SYSTEM. |
| US5583432A (en) * | 1994-04-11 | 1996-12-10 | Sci-Nostics Limited | Electrical method and apparatus for non-contact determination of physical and/or chemical properties of a sample, particularly of blood |
| US7926449B2 (en) * | 2007-06-25 | 2011-04-19 | Delaval Holding Ab | Fluid application systems and methods and milking systems and methods |
| US8757091B2 (en) * | 2009-09-18 | 2014-06-24 | Delaval Holding Ab | Arrangement and method for indicating undesired detachment of a milking member from an animal |
-
1981
- 1981-10-30 ZA ZA817526A patent/ZA817526B/en unknown
- 1981-11-02 GB GB8132972A patent/GB2090431B/en not_active Expired
- 1981-11-16 AU AU77525/81A patent/AU550268B2/en not_active Ceased
- 1981-11-18 CA CA000390349A patent/CA1180084A/en not_active Expired
- 1981-11-18 NL NL8105230A patent/NL8105230A/en not_active Application Discontinuation
- 1981-11-19 DE DE19813145888 patent/DE3145888A1/en not_active Withdrawn
- 1981-11-19 FR FR8121707A patent/FR2494084A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| AU550268B2 (en) | 1986-03-13 |
| FR2494084A1 (en) | 1982-05-21 |
| GB2090431A (en) | 1982-07-07 |
| FR2494084B3 (en) | 1983-09-16 |
| DE3145888A1 (en) | 1982-08-05 |
| NL8105230A (en) | 1982-06-16 |
| ZA817526B (en) | 1982-11-24 |
| AU7752581A (en) | 1982-05-27 |
| GB2090431B (en) | 1984-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8646411B2 (en) | Method and apparatus for milking animals having four teats | |
| EP0510779B1 (en) | A milking plant | |
| CA1051366A (en) | Electronic milker | |
| US3878819A (en) | Milking machinery control apparatus | |
| US4924809A (en) | Method for cleaning a teat of a female animal, milking method and cup for use with above mentioned methods | |
| EP0534565B1 (en) | An implement for and a method of milking animals automatically | |
| US6308655B1 (en) | Device and method for milking animals | |
| EP0954962B1 (en) | A method of and an implement for automatically milking animals | |
| US4190020A (en) | Process and equipment for machine milking to provide sterile milk free from blood and pus | |
| CA1180084A (en) | Controlling and indicating device for a milking machine | |
| US4112758A (en) | Milk monitoring method and apparatus | |
| US4190021A (en) | Automatic stimulation apparatus for milking machines | |
| US4348984A (en) | Control apparatus for milking machines | |
| US2513627A (en) | Flow indicator for milking machines | |
| US3754532A (en) | Milking machine | |
| JP2007267734A (en) | Adaptive milking system | |
| US3469596A (en) | Liquid transfer apparatus | |
| EP0759690B1 (en) | Method of milking animals | |
| US2549231A (en) | Alarm device for milking machines | |
| CN106614003B (en) | Milking controller and control method thereof | |
| EP1138192B1 (en) | Automatic milking | |
| WO2008051137A1 (en) | Method and arrangement for controlling the milking by a milking machine | |
| US6957625B2 (en) | Method and device for the improved milking of an animal, in particular of a cow | |
| GB2029029A (en) | Flowmeters | |
| JPS6146093B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |