AU683025B2 - Improvements in or relating to milking equipment - Google Patents

Description

~CIIP~L~BICP 9 I S F Ref: 257855

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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Name and Address of Applicant: Keith Weldon Jeffries 116 Gillespies Line Palmerston North NEW ZEALAND Roger Keith Fisher 8 Lifford Place Palmerston North NEW ZEALAND

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5555 Actual Inventor(s): Address for Service: Invention Title: Keith Weldon Jeffries and Roger Keith Fisher Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Improvements In or Relating to Milking Equipment The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845/3 L qas i L~lI PgWI~PISI~IB~a~B~F~- 3_ II' This invention concerns improvements in or relating to milking equipment.

In milking sheds or parlours it is a common technique to use the so called dry vacuum to carry out functions such as removal of teat cups, operation of certain functions of flow sensing devices and other like operations.

Generally the dry vacuum is used to remotely control valve or switching means.

A major problem associated with the use of dry vacuum for such functions is that contaminants can enter the vacuum system with undesirable consequences such as valves or switches becoming blocked or impaired in operation. While precautions can be taken to preclude these situations arising the very presence of the effect of vacuum at any point where contaminants or moisture can enter the system makes it very difficult to overcome this problem.

Furthermore there is an increasing trend in milking sheds for more electronic equipment to be present. Thus 20 it is important that moisture be kept away from electronic componentry. This can be extremely difficult when the vacuum lines are in the immediate vicinity of such componentry as any leakage can result in moisture and/or contaminants being drawn into the close proximity of the electrics. Also the vacuum line inherently has a level of moisture content which in many circumstances i 4s ~W ~BIBIIII~BBliBils~ AILI~ can interfere with the electronic circuitry, components etc.

The object of the present invention is to auaied4t4the problems associated with the use of negative pressures for carrying out such functions.

To this end the present invention broadly relates to equipment for use in the milking of animals such equipment including switching or valving means which is/are remotely controlled, said equipment being characterized in that remote controlled operation of the switching or valving means is effected by the application of positive air pressure.

More particularly in a second broad aspect of the invention there is provided valve or switching means for 15 equipment to be used for the milking of animals said valve or switching means including a valve element adapted aind arranged to close a negative pressure line said element being normally held in an open position by biasing means, said valve including means for coupling o 20 to a source of positive air pressure such that upon application of said positive pressure the valve eletaent can be closed against the action of said biasing means.

The present invention haslafteilff application for use in conjunction with the valving or switching means of 25 teat cup removal apparatus. Generally such apparatus Isl c a a g~eauF~rs~A-- includes valve or switching means for shutting a milk flow passage to thereby remove negative pressure fro=t the teat cups. Furthermore such apparatus generally includes a vacuum operated linear actuator (ram) which upon negative pressure being removed from the teat cups is operative to draw the teat cup cluster away from the animal which has been milked. It is a known technique to provide a valve arrangement with the ram such that the application of a negative pressure to the ram can be controlled. Furthermore it is preferable to vent the ram to atmosphere to enable free movement of the piston in the ram to occur when the teat cup cluster is taken to the animal to be milked.

Accordingly the present invention has ee application for remote control of the valve or switching means associated with the liquid flow sensor and teat cup removal ram which normally form part of such teat cup removal apparatus.

In the following more detailed description of the invention reference will be made to teat cup removal *.6C V e*n*ocUVLer-\ J apparatus the invention as illustrated in the accompanying drawings in which:- Figure 1 is a cross-sectional elevation view of a known liquid flow sensing device forming part of a 25 teat cup cluster removal apparatus but incorporating a valve or switching means neeedag tLi «®seroo=t'rA ©iu^nAe,, I~lllbaa~PT-R ~~"E~"erraaasr~l~ra~ ~b-Lle~ I- Figure 2 is a cross-sectional elevation view of a valve or switching arrangement ti- g g t which is particularly designed for incorporation with the removal ram used with teat cup removal apparatus, Figure 3 is a circuit block diagram of the main electrical and mechanical componentry of a teat cup removal apparatus incorporating the arrangement as shown in Figure 1, Figure 4 is a schematic illustration of control apparatus for use in conjunction with the aforementioned removal apparatus, and Figure 5 is an exploded view of a teat cup removal apparatus incorporating the flow sensing device.

While the present invention has application to various pieces of milking equipment which may find use in a .oeo milking shed or parlour and require remote control the following description will, as previously mentioned, relate more specifically to a teat cup cluster removal apparatus. Such apparatus can, for example, be of the type described and claimed in Australian patent eO0* specification 585281 the content of which is hereby incorporated by specific reference.

0e The flow sensing device disclosed in Australian patent specification 585281 consists of a flow sensor 10 having an inlet 11 and an outlet 12 formed integrally therewith. A conduit 13 projects from body 14 of sensor I o L U ~k gsee~J ~D~lli~lr~sr~x~i~r~ s -U so as to be diametrically opposed and coaxial with finlet 11. The free end of conduit 13 is formed as or is connected to outlet 12. Body 14 provides a cavity between inlet 11 and conduit 13.

Inlet 11 opens into an annular space 16 formed by a generally annular wall 17 which projects from the back 18 of cavity 15. As described in patent specification 585281 electrodes are provided in the flow passage so as to effectively form a coaxial capacitor.

The outer peripheral edge 19 of body 14 forms a seat on which the peripheral portion of a diaphragm 20 is mounted. Diaphragm 20 seats on the end 21 of wall 17 thereby closing the fluid flow passage between the inlet 11 and outlet 12. Diaphragm 20 is, as illustrated in Figure 1, held in place by a spring 22 (preferably a roll spring as shown) which biases the diaphragm away from seat 21. As illustrated the central portion of diaphragm 20 includes a boss 23 into which is engaged a projection 24 of the central portion of roll spring 22.

Roll spring 22 is preferably integrally formed from a suitable resilient material such as HYTREL (Reg. Trade Mark) produced by DuPont.

a A cap 25 engaged on wall 26 holds roll spring 22 in place which in turn holds diaphragm 20 about its peripheral edge by sandwiching said peripheral edge between the shoulder 27 and edge 19.

i -g ~gle--p~p~e~a ~%BBllrrplw~lu~a~r~P~ araasollll~-- Thus as illustrated by Figure 1 the valve in its "rest" position holds diaphragm 20 away from seat 21. As described in patent specification No 585281 the fluid flow 'passage connecting inlet 11 to outlet 12 is therefore open and as a consequence allows negative pressure vacuum) to draw milk from the teat cups via the milk flow passage.

A chamber 29 within the confines of roll spring 22 is formed by a combination of the profile of roll spring 22 and diaphragm 20 located there across. A small bore extends through the side wall of body 14 to open into chamber 29. This bore 30 opens to a port 31 to which is connectable a compressed air supply via control valves as will hereinafter be more fully described. Thus 15 application of compressed air via bore 30 pressurizes not only chamber 29 but also chamber 28 defined by the other side of roll spring 22 and cap 25. This chamber 28 is accessed via port 32 in roll spring 22.

Thus the compressed air acts against roll spring 22 00 20 and/or diaphragm 20 such that the diaphragm 20 is forced down onto seating 21 thereby closing the fluid flow t passage, Consequently operation of the valve takes place solely by the compressed air supply acting against .o the biasing means of spring 22 and/or diaphragm When the compressed air supply is shut off 'by the -v -C~3L~ ~IP ~$llPPL"" 8 control Yalves the roll spring 22 reverts to its normal position thereby drawing diaphragm 20 off seat 21.

Likewise in Figure 2 there is illustrated a valve arrangement 30 for attachment to the end of the body (not shown) of a vacuum operated ram for teat cup removal apparatus. This valve consists of a body having a port 41 which is attachable to a negative pressure line. A valve element or spool 42 is located within body 40 and includes a seal 43 which is engageable on seat 44. Spool 42 is, however, biased by spring 45 such that seal 43 is, in the normal state of the valve, lifted off seat 44 whereby vacuum can via port 46 be applied to the interior of the ram the body of which engages with skirt 47 of valve body Valve body 40 is coupled to an upper parL or cover 49.

Sandwiched between these two parts is a flexible element 50 which serves as a dust/contaminant seal. In the illustrated form the seal 50 is not attached to spool 42 but rather slides over the peripheral surface of the spool.

9 The upper end of spool 42 has a cup seal 51 which is slidingly engaged in a peripheral skirt 48 which projects downwardly from the underside of cover 49. A connection 54 enables a compressed air line to be attached such that compressed air can be supplied to the chamber 55 defined by the cup washer 51 and top p ila gars~--~-n I a I portion/peripheral skirt of cover 49. Thus by the application of compressed air, spool 42 is forced downwardly against the biasing effect of spring 45 such that seal 43 engages on seat 44 to cut off negative pressure from the interior of the ram.

Valve body 40 includes an inlet or vent 57 whereby via port 59 (which is uncovered when seal 43 moves onto seating 44) the interior of the ram is fully vented to atmosphere. This enables the piston within the ram to be freely drawn along the body of the ram by a force applied to the tether coupling the piston rod to the teat cup cluster.

To further describe operation of the valves shown in Figures 1 and 2 reference will now be made more particularly to the operation of an improved construction of the liquid flow sensing device as described in patent specification 585281.

0 The sensor in operation detects the amount of liquid 2U flowing through the sensor and as described in patent specification 585281 the electrodes effectively form a capacitor with the dielectric being formed by the liquid a* 0 within the annular space 16.

0 *"oo The electrodes are located on the outside of the walls not in the milk flow). This eliminates a major I RA\ I -k PBFY ~i ePql~--48)3~) PY~ I~ll~l~rP i~l'mY0 cause of trickle voltage from one cow bale to the next or to ground as the electrodes are insulated from the milk. As the liquid is a dynamic flow of milk and air the capacitance between the electrodes varies in proportion to the amount of liquid in the flow, i.e. the more liquid in the flow the higher the capacitance.

This capacitance variation is used to vary the frequency of an oscillator, the variable frequency is then detected with the result that the varying capacitance represents the varying flow rate. By means of a microprocessor and software the variations in the oscillator frequency are translated into a flow rate.

Sensor 10 is connected with oscillator 66. In the preferred form of the invention oscillator 66 is of a high frequency type.

The oscillator 66 is coupled via a divider 67 to a microprocessor 68. An EEPROM 69 for data retention is *0* ,coupled with micronrocessor 68.

The display driver 70 drives a bar graph display 71 *5 20 (formed by a plurality of LED's) and is connected to the microprocessor's I/O port. An actuation air switch is coupled via debounce 76 to microprocessor 68. The switch 75 is preferably an air switch which is coupled :.to a 2lne leading to a resilient bulb located in the vicinity in which the operator works, e.g. adjacent the teat cup cluster which is connected via a milk line to I CLISIIIB~e IC---b-FII I~aB inlet 11. Upon the operatr squeezing the bulb, air pressure in the line leading to switch 75 causes the switch to operate.

The device can operate in either an automatic or a manual mode. In the preferred form of operation a single operation of switch 75 results in automatic mode of operation being selected (this being indicated in the display section by flashing "auto" light 77). Two operations of switch 75 results in selection of the manual mode and illumination of a flashing "manual" light 78 in the display section. The operator can therefore readily select manual or automatic mode of operation and observe whether the device is in the automatic or manual mode of operation by reference to *0 15 indicator light 77 and 78.

0.0.0 In a typical operation the operator will activate switch 75 once to select automatic mode whereupon a solenoid valve 79 driven by solenoid driver 80 is operated so that compressed air can be exhausted from the chambers oe 0° 28 and 29 via valve 79 in order that roll spring 22 can lift diaphragm 20 off seating 21. The flow passage is 00 thus opened. As a consequence negative pressure is present at the teat cups and they can be applied to the •animal.

Simultaneously solenoid driver 81 operates solenoid valve 82 and connects compressed air to chamber 55. The IIB~4lrarPnaeas~sasl~a*s~r~compressed air via a piston 51 forces spool 42 to move against spring 45 and in so doing switches negative pressure from the ram and allows atmospheric air to enter the ram via vent 57, port 59 and port 46.

At the end of milking negative pressure is disconnected from the outlet 12 (and hence the teat cups) prior to negative pressure being connected to the ram. The delay time between switching solenoid valves 79 and 82 can be set by the operator using an infra red hand held controller and the setting stored in the memory chip 69.

This delay permits negative pressure to decay to zero in the teat cup or a level set by the operator before the ram removes the teat cups.

A hand held infra red controller 73 is used by the .e 15 operator to adjust or set the following in memory 69 via the transmitter/receiver 87:- 1. Flow rate setting 2. End point timer 3. Minimum milking time 4. Delay time between switching negative pressure from the sensor and to the ram.

5. On-Off switch for remote take-off transmitter 6. Bale number 7. Entering a pin number to deactivate security system after a pre-set number of milkings 8. Cow identification number.

i 4 ly -L ~LL pl 1 ~4~ ICIP"CIIWI~W II 1-~rU r 13 Thus a driver 88 coupled to microprocessor 68 enables transmissions to the controller to take place while signals from the controller are received by microprocessor 68 via filter amp 89 and detector 87.

Notwithstanding the pre-set flow rate setting (i.e.

take-off flow rate), which is operator adjustable and set in memory 69, the microprocessor 68 operates to ensure the cups are not removed for the minimum milking time even if the flow never reaches or remains below the take-off flow rate setting. The unit operates thereafter in manual mode and will not become flow controlled. This operational phase ensures that allowance is made for animals whose actual let down follows some time after an initial flow of milk occurs 15 when the teat cups are first placed on the animal.

4* a .i When the pre-set flow rate setting has been exceeded and when milking is nearly completed and the flow rate falls below the flow rate setting the microprocessor 68 establishes a time delay that is set by the user with hand held remote 73 so that there is a delay between the S: flow being reached and the solenoids 79 and 82 being operated. Cup removal can, however, be achieved at any time (after selection and a small delay time) by S. operating the switch 75. If during the time delay sequence, however, flow exceeds the pre-set flow rate setting the microprocessor 68 will count back up to the end point timer setting set by the user for the time I~es LIIM slg~Bll~s~BIW~ra~-q 'I C ILIIIIBarrr~rr~3 ~s 14 that the flow rate remains above the flow rate setting if the flow continues for a sufficient length of time otherwise it will count back up for a period commensurate with the time the flow rate is above the preset flow rate setting.

Activation of solenoid valve 79 causes compressed air to pressurize chambers 28 and 29 and force diaphragm onto seating 21 and thereby disconnect negative pressure from outlet 12. Deactivation of solenoid valve 82 causes compressed air to be exhausted from chamber which consequently results in negative pressure being applied to the ram body to cause the ram to operate and draw the teat cups away from the animal. The time delay between switching solenoid 79 and 82 has been previously 15 described so that the operator can determine the vacuum delay level required.

The manual mode of operation is selected by the operator using switch 75 twice but within the delay time mentioned above. In this manual mode of operation cup *o S 20 removal is initiated by operating switch 75. Whilst the o bar graph display 71 will still indicate flow during manual operation cup removal is no longer dependant on the actual flow rate. It is envisaged that the main got• application for the manual mode of operation would be r during a wash cycle where the unit can be left in this mode until the wash cycle is completed or for problem cows.

IpP~e~rP-~ I- Rerote take-off or cluster remove override feature provides for instantaneous removal of the cluster from an animal irrespective of milk flow or mode. This section is intended primarily for use in rotary milking parlours where operators may wish the clusters to be removed at a certain position of the platform independent of milk flow or mode. Remote take-off conveniently consists of the receiver 87 which senses an infra red signal from an infra red transmitter 74 mounted at the position of the platform at which an operator wishes the clusters to be removed. The receiver 87 is thus coupled to the microprocessor 68 via filter amp 89 when actuated by the microprocessor 68.

Solenoid driver 80 powers up solenoid valve 79 and t 15 driver 81 turns power off to solenoid 82.

S. As shown in Figure 5 a typical arrangement of teat cup 0 S* removal apparatus can comprise first and second housing sections 100 and 101 in which sensor 10 locates into irecesses 102 and 103 providing apertures through which inlet 11 and outlet 12 can engage. Located within the housing is a circuit board 104 which incorporates the

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main electronic circuitry as herein described as well as S..LED display 71. A transparent cover 105 is located external of housing section 101 an, through which LED's 71 are visible.

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bwaaDmna~op Illustrated in Figure 5 are fittings 106 and 107 for coupling of a compressed air supply line to nipple 108 of solenoid block 109 and an air line between nipple 110 and the removal cylinder. The short tube 111 couples nipple 112 to sensor The air switch line (not shown) from the activating bulb is coupled via fitting 116 to air switch In a preferred arrangement of the foregoing remote takeoff embodiment the sensing device is constructed and programmed such that upon the teat cup cluster being removed by the remote take-off the LED's showing the flow rate at the time of removal start to flash. Thus if the flow rate at the point of removal was indicated by say three LED's being lit these three LED's will 6 15 start to flash. The flashing LED's thus indicate to the S. farmer that the cups were removed from by the previous cow by the remote take-off and the flow rate at the time of removal.

This information enables the farmer to determine that 20 the speed of the platform is either too slow or too 'V fast. Thus the farmer can speed up or slow dowi the platform. This can be carried out manually, however, it is envisaged that with a more sophisticated control system automatic sensing can determine whether the platform speed should be automatically adjusted' by the central control. In this way it will be possible to ISISy;Epr~-~ I- c* 17 optimise the flow rate at which the remote take-off removes the cups.

In a further arrangement the sensing device can be arranged to have an array of LED's (say every second LED) flash if no milk has passed through the sensing device during the milking of the previous cow.

As illustrated in Figure 4 a power line modum can be employed for data transmission and reception. In the drawing a master controller 90 is hard wired via bidirectional line 91 to a plurality of sensor units Sl Sn. The power supply is indicated by "PS" and the modum by Thus the sensor units are all supplied with power from the master controller 90, however, data can be transmitted along line 91 from one, some or all of the sensor units when requested by controller Thus the controller 90 can record relevant data transmitted from sensor units S1 Sn.

*9 By using positive air pressure to operate the flow sensor valve and the venting/switching arrangement for 20 the removal ram there is a considerable reduction in the possibility of contaminants/liquids being drawn into the casing of the teat cup removal apparatus. Thus mechanical and/or electrical failure is reduced and hence reliability of the whole unit increased. The source of positive air pressure can be positioned in a L B ~BI~Y~Rlrmaaa~ss separate environment to the milking environment and thus away from possible contaminants.

In a preferred form of the invention air is, during each operation, vented into the interior of housing 100/101 to help keep the interior and hence electrical circuitry dry. To this end a drier (not shown) can be incorporated to dry the compressed air flowing in the removal apparatus.

The foregoing can be achieved by different means.

According to one preferred embodiment one of the valves 79 and 83 vents into the interior of the housing. For example, the exhaust port of valve 79 can be coupled to an exterior chamber formed in housing part 100 and .covered by cover plate 113. This chamber is vented to 15 atmosphere. By contrast the exhaust port of valve 82

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can vent directly into the interior of the housing. An aperture (not shown) in wall 114 of housing port 100 opens into the aforesaid chamber but is covered by a filter 115 which is preferably made of a material (such as Wettex) which has a capillary action. Filter 115 is preferably L shaped as shown so that the foot thereof lies on the floor of the interior of the housing.

*4 Accordingly, moisture build up in the interior tends to too$ accumulate on the floor and becomes absorbed by the foot of filter 115. The moisture then migrates up the' leg of filter 115. Thus when valve 92 vents it flushes the I, -~sr Pawa~Pasl r;1~411 interior with air and forces moisture in filter 115 through the aperture into the chamber covered by cover 113 whereupon it drains away through a suitably positioned opening.

As a result of the cyclic air flush the electronics within the housing are kept dry. Hence a sealed housing to prevent ingress of moisture is not required.

The invention is not confined solely to teat cup removal apparatus but can apply to other milking shed equipment.

For example, the use of positive air pressure to carry out switching functions for valves or switching means can equally be applied to milk flow measuring apparatus.

i" A further advantage with the present invention is that air drying apparatus can be used to dry the air being 15 used for control of the servos. This drying apparatus could be located at the source of the compressed air and thus away from possible contaminants.

a C A yet further advantage over conventional systems is that the known system using dry vacuum for control g.

20 purposes is that at start up of the milking system a certain number of teat cup clusters need to be closed in order to get vacuum operated valves to actuate. With the present system the positive air pressure closes all valves at start up.

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Claims (15)

1. Equipment for e&=ia- the milking of animals such equipment including switching or valving means which is/are remotely controlled, said equipment being characterized in that remote controlled operation of the switching or valving means is effected by the application of positive air pressure.

2. Valve or switching means for equipment be-ei*uc"a for the milking of animals said valve or switching means including a valve element adapted and arranged to close a negative pressure line said element being normally held in an open position by biasing means, said valve including means for coupling to a source of positive air pressure such that upon application of said positive 15 pressure the valve element can be closed against the a. action of said biasing means. g .:a

3. The valve or switching means of Claim 2 wherein a seating is associated with said negative pressure line and said valve element includes a seal arranged to SO* o 20 sealingly engage with the seating upon said application C of the positive pressure. C

4. The valve or switching means of Claim 3 wherein the S.oo seal is a diaphragm and said biasing means is a roll spring coupled with the diaphragm. p IIIP ~PII~YC~I The valve or switching means of Claim 4 wherein the diaphragm and roll spring define a chamber to which the positive pressure can be applied to cause the diaphragm to move out of the seating.

6. The valve or switching means of Claim 5 wherein the roll spring at least in part defines a further chamber to which said positive pressure can be appljed to at least reduce the biasing effect on the diaphragm.

7. The valve or switching means of Claim 3 wherein the valve element includes second seal which at least in part defines a chamber to which said positive pressure can be applied, the biasing means being a spring, said valve element being mounted for movement along an axis against the biasing force established by said spring 15 such as to move said seal onto said seating when e positive pressure is applied to said chamber.

8. The valve or switching means of Claim 7 wherein said second seal is a cup seal located in a bore the axis of said bore being coaxial or parallel to the axis 20 of movement of said valve element.

9. The valve or switching means of any one of Claims 2 to 6 in combination with a flow passageway of a liquid flow sensor. I I 22 The valve or switching means of any one of Claims 2,3, 7 and 8 in combination with a body of a vacuum operable ram.

11. An electronic milk flow sensor including a valve or switching means as claimed in any one of Claims 2 to wherein a housing contains electronic componentry of the flow sensor, there being means whereby air derived from said positive air pressure is, during an operation of the flow sensor, vented into the housing.

12. An electronic milk flow sensor as claimed in Claim 11 wherein a solenoid valve for control of said positive air pressure to the valve or switching means has a vent port which vents into said housing.

13. An electronic milk flow sensor as claimed in aim 15 11 or 12 wherein the housing includes a moisture acc,3mulator and an absorbent element for absorbing moisture in said accumulator, said venting air forcing absorbed moisture from said housing through a moisture S release opening provided in said housing.

14. An electronic milk flow sensor including a valve or switching means as claimed in any one of Claims 2 to said milk flow sensor including a microprocessor control unit and a remote controller whereby operation and adjustment of the operation of the flow sensor can be carried out remotely. A teat cup removal device incorporating a milk flow sensor as claimed in Claim 11 or 12 and a ram for removal of teat cups from an animal, said ram incorporating a valve or switching means as claimed in any one of Claims 2, 3, 7, 8 and

16. A teat cup removal device as claimed in Claim further including solenoid valves adapted to be coupleable to a source of compressed air, said solenoid valves being operable by control means to direct a compressed air flow to the valve or switching means in said flow sensor and after a time delay established by the control means disconnect fluw of compressed air to the valve or switching means of the ram. 9. *O

17. A teat cup removal device as claimed in Claim 16 15 wherein the control means is formed by a microprocessor, said microprocessor establishing a minimum flow rate at which the teat cups are removed from an animal, the microprocessor also establishing a time delay after said .9 minimum flow rate is reached prior to activating said 20 solenoid valves. 9* S18. A teat cup removal device as claimed in Claim 17 wherein the microprocessor includes means for delaying operation of the solenoid valves in the event of the flow rate as sensed by the flow sensor exceeding the minimum flow rate before the said time delay expires. I I AIY 24

19. Valve or switcihing substantially as herein described with reference to Figures .1 or 2 of the accompanying drawings. A teat cup removal device substantially as herein described with reference to the accompanying drawings. DATED this SIXTH day of DECEMBERZ 1993 Keith Weldon Jeffries Roger Keith Fisher Patent Attorneys for the Applicant SPRUSON &FERGUSON *fee 0 *goo ABSTRACT s"VALVE OR SWITCHING MEANS FOR MILKING EOUIPMENT" a. Vale or switching means for equipment to be used for the milking of animals. The valve or switching means 5 includes a valve element (42) adapted and arranged to close a negative pressure line Valve element (42) is normally held in an open position by a biasing spring A source of positive pressure can be coupled via a a coupling (54) so that positive r iessure to a chamber l0 (55) causes the valve element (42) to move against the action of the spring (45) and via a seal (43) close the vacuum line (41). (Figure 2)