GB2232335A - Liquid feeding system - Google Patents

Abstract

A liquid feeding system primarily intended for pigs includes a trough 52 and a vertically displaceable rod 72 having lifting means 76, 78 at a lower end thereof. Lifting of the rod 72 by, for example, a pig's snout, actuates valve means 64 which releases pressure on a diaphragm valve 60 located in a feed pipe 54 dispensing food into the trough 52. The pressure released from the diaphragm valve 60 pressurise an exhaust line and actuates pressure switch 70 to operate a pump (not shown) so as to supply more feed to pipe 54 via pipe line 58. Where the rod 72 drops down the valve means 64 is closed, the diaphragm valve 60 re-pressurised and pump switched off. Thus food is dispensed automatically in response to demand by animals and without the use of electronics within the feeding station. <IMAGE>

Description

LIQUID FEEDING SYSTEM This invention relates to a liquid feeding system especially such a system for dispensing liquid foodstuffs to pigs.

Generally speaking there are two ways in which foodstuffs can be provided to a piggery. In the first place the food can be supplied at predetermined intervals, "feeding times", in response to a timed or manually operated control system. Alternatively, the system may provide for "ad lib" feeding whereby food is dispensed in accordance with demand placed upon it.

Feeding systems using dry foodstuffs are fairly easy to construct for example using a hopper maintained at a predetermined level by a screw conveyor. Wet or liquid feeding presents difficulties. This invention is concerned with "ad lib" liquid feeding systems.

One prior known "ad lib" liquid feeding system, known as the "river system", has been in use for some twenty years. This system can only be used when the piggery is sited on sloping ground, for example on the side of a hill. The foodstuff is mixed at the lowest level and pumped to the highest point of the system. It then flows under the action of gravity via feeding troughs distributed throughout the piggery back to the mixer on a continuous cycle. A disadvantage of this system however is that any fouling of the troughs at intermediate levels is then distributed throughout the system. Thus, diseases may be quickly spread throughout a piggery.

An alternative system which has only been comparatively recently introduced into the market consists of a single feeding station using a short length of trough. A low voltage electrode probe detects high and low levels of liquid within the trough and in conjunction with a solenoid valve controls the introduction of additional feedstuffs to the trough. In this way the trough may be kept topped up as food is consumed by the pigs. One problem with such a system however it that each feeding station requires its own set of electronic components in the control system and furthermore the presence of electronic components in close proximity to a liquid and also in a fairly humid atmosphere leads to excessive failure and breakdown of the control circuitry.

It is an object of the present invention to provide an improved liquid feeding system which will dispense a liquid foodstuff on demand and overcome the disadvantages present in the heretofore known systems.

According to the invention we provide a liquid feeding system including a liquid receptacle and switching means disposed relative to the receptacle so as to be actuable by an animal feeding from the receptacle, the switching means controlling dispensing apparatus operable to dispense liquid foodstuff into the receptacle.

In one embodiment of the invention the switching means is a lever, one end of which is provided with a pad disposed within the liquid receptacle, the other end of the lever being connected to valve means operative to control a liquid flow rate along a feed line into the liquid receptacle. Thus a pressure by an animal on the pad located in the liquid receptacle causes operation of the valve means and the dispensing, into the receptacle, of a quantity of liquid feed.

In a second embodiment of the invention the switching means is a rod, one end of which is provided with lifting means, the other end of the rod being connected to valve means operative to control a liquid flow rate along a feed line into the liquid receptacle.

In this embodiment the animal's snout lifts the rod causing the valve means to operate and dispense a quantity of liquid feed.

A further aspect of the invention is that the liquid receptacle has a cross section which is narrower at its bottom than at the top and the switching means is located substantially towards the bottom of the receptacle. In this configuration it is envisaged that the switching means will be operated by contact with an animal's, for example a pig's, snout, which contact will be released quickly when the bottom of the receptacle is filled with liquid feed. In this way overfilling of the receptacle is prevented and a minimal amount of foodstuff is standing within the receptacle at any one time.

Advantageously the valve means are pneumatic valves attached to an air line such that operation of the switching means releases air from a pneumatic valve disposed to control the dispensing of the feedstuff, the valve remaining open for a period of time dependent upon the time taken to repressurise the air line to the pneumatic valve. This time can, of course, be pre-set to any desired period such that a predetermined quantity of feedstuff may be admitted to the receptacle via one contact with the switching means.

Preferably, the air released from the pneumatic valve operates a pressure switch so as to actuate a feed pump and supply further liquid foodstuff to the dispensing apparatus. In this way a constantly renewed supply of foodstuff is maintained in the dispensing apparatus.

In case of failure of one or more valve means, which would mean that foodstuff would be constantly pumped through the faulty valve and hence lost, it is advantageous to provide a level detector in the receptacle operative to detect an abnormally high level of footstuff in the receptacle and operative to close the feedstuff dispensing pipeline on detection of such a level.

An important advantage of the feeding system according to the invention is that foodstuff is only dispensed on actuation of the switching means thus if the system is closed down, for example at night time, an unusually high demand would not be made on the system on its start up. It will be appreciated that with a system controlled only by the level of the foodstuff in a receptacle only on start up all feeding stations would simultaneously call for a quantity of food at the same time and it is necessary therefore to provide further electronics to prevent such a demand overloading the system.

A further advantage of the invention is that it can be installed to existing manually operated systems with a minimum of disruption to operation and can also utilise all existing pipework with the addition of the necessary valve means.

A specific embodiment of the invention will be described further, by way of example, with reference to the accompanying drawing in which: Fig. 1 is a simplified view of a first embodiment of the invention; and Fig. 2 is a similar view of a second embodiment of the invention.

Referring to Figure 1, a first embodiment of a liquid feeding system includes a liquid receptacle in the form of a trough 12 which is provided in a piggery or animal enclosure (not shown). The trough 12 has a cross-section which is narrower at its bottom 14 than at its open top 16. A feed line 18, commonly of 2 inch diameter pipe, is provided with an open end disposed within the trough 12. Thus a liquid feed dispensed from the feed line 18 will be contained within the trough 12.

The feed line 18 is connected to pipework 20 which is eventually connected to a feedstuff supply (not shown) which may include a mixer and a pump or other processing machinery.

A plate 22 is disposed within the trough 12 so as to create a gap 24 between a lower edge of the plate 22 and the bottom 14 of the trough 12. A support 26 is secured to one side of the plate 22 and a lever 28 is pivotally connected at its mid point to the support 26.

One end of the lever 28 is provided with a pad 30 and the lever is configured such that the pad 30 projects through the gap 24 below the plate 22. Thus the pad 30 is substantially close to the bottom 14 of the trough 12. The lever's other end 32 is disposed so as to actuate an exhaust valve 34 which is connected to an air supply line and a pneumatic valve 38. The valve 38 is disposed to control the flow of a liquid feed (not shown) along the feed pipe 18.

An adjustable flow valve 40 is provided on the connection between the pneumatic valve and the air supply line 36. An isolation valve 42 and an air chamber 44 are also provided between the exhaust valve 34 and the pneumatic valve 38. A hand operation valve 46 is also provided operable to manually override the system and control the pneumatic valve manually if so desired.

In use the feeding system functions as follows.

An animal, for example a pig, pushes its snout against the pad 30 causing the lever 28 to move about its pivot.

The end 32 of the lever pushes against the exhaust valve 34 opening an exhaust port in the valve and releasing pressure from the pneumatic valve 38. The pneumatic valve 38 on opening permits a liquid foodstuff to flow from the pipework 20 along the feedline 18 into the trough 12.

As the level of the liquid feed within the trough rises the pig is forced to remove its snout from the pad 30 causing it to return to its original position under the influence of a spring 29. This removes contact of the lever 32 on the exhaust valve 34 closing same and permitting air from the air supply line 36 to re-pressure the system. The rate at which the system is re-pressurised is determined by the rate at which air is permitted through the flow valve 40 and the size of the air chamber 44. On re-pressurisation the pneumatic valve 38 is closed and the flow of liquid feed along the feedline is once more interrupted. Thus the quantity of liquid feed dispensed by one push of the pad 30 may be predetermined by sizing of the needle valve 40 and the air chamber 44.

As the pig feeds on the liquid foodstuff its level in the trough 12 decreases and thereby permits the pig's snout access to the pad once more. Thus the supply of liquid within the trough 12 may be replenished at intervals until the pig has had enough to eat. The isolation valve 42 may be closed to prevent further dispensing of liquid feed in response to control of the exhaust valve 34. Furthermore the hand operation valve 46 may be operated to release pressure from the system and hence open the pneumatic valve if it is desired to permit foodstuff into the trough when not demanded by a pig.

In the preferred embodiment a probe 48 in the form of an electrode is provided for the detection of an abnormally high level of foodstuff within the trough 12.

Such an abnormally high level may occur either due to a faulty exhaust valve 34, a fault in the pneumatic valve 38 or in the hand operation valve 46. On the detection of an abnormally high level the electrode 48 is operative to at least sound an alarm or preferably close the pump supplying feed stuff to the pipework 20.

Alternatively a ball float mechanism may be substitued for the electrode to detect an abnormally high level of feedstuff in the trough. However, such a mechanism may be rendered inoperative due to the semi-solid nature of the liquid feedstuff present in the trough 12.

Although the preferred embodiment operates using a pneumatic control system this is not necessary and a microswitch may be substituted for the exhaust valve 34.

The microswitch could then either control a pneumatic valve as previously or a solenoid valve could be provided at position 38 on the feedline 18. However, a dependence on electrical and electronic circuits is not advantageous in the environment in which the invention is intended to be used and hence the pneumatic system described is preferred.

In Fig. 2 a second embodiment is illustrated which provides for an improved dispensation of liquid feed. In this second embodiment a trough 52 of substantially U-shaped cross-section has a liquid food pipe 54 attached to a reat wall 56 thereof. The pipe 54 is connected to a pipe line 58 leading to a feedstuff supply (not shown). A pneumatic diaphragm valve 60 is placed within the pipe 54 so as to block the pipe when the valve 60 is pressurised. An adjustable control valve 62 regulates the rate at which pressure is applied to the valve 60 and hence the amount of food dispensed during one operation of the system.

The valve 60 has an exhaust line which connects to valve means 64 which is normally closed thus maitaining pressure in the diaphragm valve 60. The exhaust line also includes a relief valve 66 to prevent over pressurisation of the line in use and a flow control valve 68 to regulate the rate at which the exhaust line pressure returns to zero after use. The exhaust time also contains a pressure switch 70 which is connected to and controls a pump (not shown) in the pipe line 58.

The valve means 64 is operated by a rod 72 which is attached to a back plate 74 which is preferably tilted directly onto the trough 52. The rod 72 is secured so that it may be moved in a vertical direction only. To facilitate such lifting a plate 76 is attached to the rod's lower end along with a played bar arrangement 78.

In use a pig will lift the rod 72 by placing its snout under the plate 76 and bar arrangement 78. The lifting of the rod 72 will operate valve 64 releasing pressure from the diaphragm valve 60 to the exhaust line. The diaphragm valve 60 is then opened dispensing food from the pipe 54 to the trough 52.

The pressurisation of the exhaust line actuates the pressure switch 70 wqhich starts the pump to force further food into the pipe 54. The excess pressure is released via the relief valve 66 or the flow control valve 68. When the rod 72 is allowed to fall the valve 64 is closed and the diaphragm valve 60 re-pressurised.

The pressure in the exhaust line is released by leakage through the relief valve 66 and the control valve 68 until the pressure switch 70 is closed and the pump switched off. If a longer pump running time is required wither the control valve 68 may be adjusted to reduce the leakage rate or an electronic timer may be provided in conjunction with the pressure switch 70 and the pump.

A stop 80 is attached to the back plate 74 so as to limit the amount of movement available to the rod 72.

The bar arrangement 78 may be modified so as to be higher and further forward to permit use by smaller animals.

The embodiments described are intended to be illustrative of the invention and variations may be made thereto. For example the air chamber 44 and isolation valve 42 are not strictly necessary to the invention and may be omitted. Alternatively the isolation valve 42 may be in the form of a jack plug.

The hand operation valve 46 may also be omitted if desired. The probe 48 may be any convenient level detecting apparatus such as a proximity switch or moisture sensitive operative to control a valve or pump on the feedline 18 so as to prevent the ingress of any further liquid to the trough 12. The pivot point of the lever 28 is not necessarily at the mid point and may be adjustable or alterable to provide different leverage forces which is especially useful for young or small pigs. The method of controlling actuation of the foodstuff pump by use of the exhausted diaphragm valve.

air may also be used in the first embodiment. In this case the air released from the exhaust valve 34 is supplied to a pressure switch as described in the second embodiment. Other variations are also possible.

Claims (8)

1. A liquid feeding system including a liquid receptacle and switching means disposed relative to the receptacle so as to be actuable by an animal feeding from the receptacle, the switching means controlling dispensing apparatus operable to dispense liquid foodstuff into the receptacle.

2. A feeding system as claimed in Claim 1 in which the switching means is a lever, one end of which is provided with a pad disposed within the liquid receptacle, the other end of the lever being connected to valve means operative to control a liquid flow rate along a feed line into the liquid receptacle.

3. A system as claimed in Claim 1 in which the switching means is a rod arranged to be displaceable in a vertical direction, one end of the rod being provided with lifting means and being disposed substantially within the liquid receptacle, the other end of the rod being connected to valve means operative to control a liquid flow rate along a feed line into the liquid receptacle.

4. A system as claimed in Claim 1, 2 or 3 in which the liquid receptacle has a cross-section which is narrower at its bottom than at the top and the switching means is located substantially towards the bottom of the receptacle.

5. A system as claimed in any preceding claim in which the valve means are pneumatic valves attached to an air line such that operation of the switching means releases air from a pneumatic valve disposed to control the dispensing of the feedstuff, the valve remaining open for a period of time dependent upon the time taken to repressurise the air line to the pneumatic valve.

6. A system as claimed in claim 5 in which the air released from the pneumatic valve operates a pressure switch so as to actuate a feed pump and supply further liquid foodstuff to the dispensing apparatus.

7. A system as claimed in any preceding claim in which a level detector is provided in the receptacle so as to detect an abnormally high level of foodstuff in the receptacle and operative to close the feedstuff dispensing pipeline on detection of such a level.

8. A system susbstantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.