Description

The present invention relates to a system for processing cattle feed, comprising a loosening element for loosening feed from a stock of feed, moving means for moving the loosening element in the vicinity of the stock of feed, and conveying means for conveying feed that has been loosened by the loosening element to a processing location.

Schuitema, a Dutch company, markets under the name of Innovado an autonomous mixer feeder provided with a mixing tub and with a pivotable arm that is provided with a silage cutter head at the end thereof. Whilst the autonomous mixer feeder is stationary, the silage cutter head moves along a stock of silage in use in that the arm pivots about a horizontal pivot axis. While doing so, the silage cutter head cuts silage from the stock of silage. The loosened silage is carried over the edge of the mixing tub of the mixer feeder and deposited into the mixing tub by means of a conveyor belt that extends within the interior of the arm. Transponders are provided in the yard and the shed(s), which transponders are used to enable the mixer feeder to drive autonomously across the yard and in the shed(s), for example to various locations where feed components are introduced into the mixing tub, and in the shed for automatically feeding cattle. In practice the autonomous mixer feeder will drive to and fro a number of times, in any case between the stock(s) of silage and the shed(s).

Although far-reaching automation of the feeding of cattle is realised with the known autonomous mixer feeder as described above, it has a few drawbacks. For example, an extensive infrastructure of transponders is required. Furthermore, an autonomous vehicle will always involve some risk to the safety of man and animal on the yard.

The object of the invention is to provide a system as described in the introductory paragraph which is suitable for processing feed, in particular (but not exclusively) silage, in a fully or partially automated manner, but which offers a solution to the aforesaid drawbacks or at least alleviates these drawbacks. In order to achieve that object, the conveying means comprise pressure means comprising a pressure pipe and at least one pressure element, which pressure pipe has a suction nozzle at one end thereof, and which pressure means are configured for conveying feed that has been loosened by the loosening element from the loosening element, via the suction nozzle, through the pressure pipe in the direction of the processing location under the influence of the pressure difference created by the at least one pressure element within the pressure pipe directly after the feed has been loosened, wherein the moving means are also configured for moving the suction nozzle jointly with the loosening element in the vicinity of the stock of feed. The use of the pressure means makes it possible in a very suitable manner to transport loosened feed directly from the loosening element to the processing location, or at least in the direction thereof, as a result of the pressure difference in the pressure pipe. The above words "in the direction of" must not be given an absolute interpretation herein, in particular they do not exclude the possibility that the path of transport between the suction nozzle and the processing location extends in a non-straight line. In an absolute sense, the loosened feed could thus even move in a direction away from the processing location in parts of the path of transport. At the location of the processing location, the system may for example comprise a mixing device provided with a container with a mixing element disposed therein, in which case the conveying system will be configured to transport the feed into the container. In the mixing device, the loosened feed can be mixed with other feed components, which have for example been loosened in a comparable manner from another stock of feed and have been transported to the container. The mixing device may form part of a mixer feeder both of the manned type and of the unmanned, autonomous type. An example of a mixer feeder of the latter type is for example the mixer feeder that forms part of the feeding system as marketed by Lely, a Dutch company, under the name of Vector. The mixing device may also be configured to be suspended or at least capable of being suspended from a crane system or a transport guide in a shed, in which case the mixing device can be moved through the shed in suspended condition, for example above a feed alley therein for delivering feed at the longitudinal edges of the alley for presenting the feed to the cattle in this manner. Such mixing devices form part of feeding systems as marketed by Trioliet, a Dutch company, under the name of Triomatic. The processing location may also be a buffer location where the loosened feed, for example in a buffer container, is stored temporarily, for example in a buffer container, before the loosened feed is fed to the mixing device, as is also known from the Triomatic feeding system. In general, the processing location will be a location that has a specific function in the processing of feed. European patent application EP 2 879 483 describes described with reference to figure 1 1 a feeding system wherein feed loosened from a stock of feed is transported into a hopper by means of an upwardly sloping conveyor belt. The hopper leads to a fan, which blows the feed into a discharge tube. Such a system has the drawback that moving parts of the conveyor belt are present close to the loosening element that is used, so that the conveyor belt is high-maintenance and susceptible to malfunction.

The invention is in particular (but not exclusively) suitable for use with a stock of feed in the open air, for example if the stock of feed consists of silage. Such stocks can cover relatively large areas. Within this framework it is preferable if the stock of feed is an uncovered stock.

For the joint movement of the suction nozzle and the loosening element it may be advantageous if the loosening element and the suction nozzle are connected.

An effective sucking action effect can be realised if the suction nozzle is provided above the loosening element. In this way a greater freedom of movement for the loosening element is created.

As already indicated before, the invention is suitable in particular for use with silage. For that situation it is advantageous if the system is provided with two parallel longitudinal walls for retaining the stock of feed therebetween.

A reliable embodiment, which can be used advantageously in particular with silage, can be obtained if the moving means comprise a horizontally extending first guide, along which the loosening element is movable in a first horizontal direction of movement, in particular if the moving means are further configured for moving the first guide together with the loosening element in a second horizontal direction of movement perpendicular to the first horizontal direction of movement above the stock of feed. Seen in top view, a complete stock of feed can thus be covered and therefore be accessed.

If use is made of two longitudinal walls with the stock of feed present therebetween, as discussed in the foregoing, it will be advantageous if the second horizontal direction of movement is parallel to the two longitudinal walls.

A reliable and relatively inexpensive way of moving the first guide in the second horizontal direction of movement can be obtained if engaging means are provided on the sides remote from each other of each of the two longitudinal walls, which engaging means are each provided with a row of regularly spaced engaging elements, which rows extend parallel to the second horizontal direction of movement, and wherein the moving means for each of the engaging means are provided with a connecting element that is movably connected to the first guide, being configured to be connected to at least one of the engaging elements of the associated engaging means, wherein the moving means comprise indexing means for repetitively

moving at least one of the connecting elements into engagement with at least one of the engaging elements,

moving the at least one connecting element and the first guide by a stroke length in the second horizontal direction of movement relative to each other for moving the first guide by the stroke length in the second horizontal direction of movement, wherein a force is exerted that acts between the at least one connecting element and the at least one engaging element,

releasing the engagement between the at least one connecting element and the at least one engaging element, and

moving the at least one connecting element by a stroke length in a direction opposite to the second horizontal direction of movement relative to the first guide, wherein the first guide remains stationary.

The stroke length can be selected to suit the desired thickness of a section of a stock of feed that is to be loosened by means of the loosening element. A suitable thickness ranges between 20 cm and 30 cm, for example, to which end the engaging elements are likewise provided at intervals ranging between 20 cm and 30 cm.

The reliability and simplicity of the system can be further improved if the moving means comprise a second guide, along which the first guide is movable in the second horizontal direction of movement.

The second guide may advantageously comprise two second guide means extending parallel to each other, wherein the system comprises two first guide means connected to the first guide at opposite ends of the first guide for guiding cooperation with the two second guide means.

If use is made of two longitudinal walls with the stock of feed present therebetween, as discussed in the foregoing, it may be preferable that the two second guide means are each provided on one of the two longitudinal walls, or that the two second guide means are provided on sides remote from each other of the two longitudinal walls. The moving means may comprise a carrier with running wheels, which carrier comprises the first guide. If use is made of a second guide as discussed in the foregoing, the running wheels may form the first guide means.

If use is made of two longitudinal walls with the stock of feed present therebetween, as discussed in the foregoing, it may be preferable if the carrier has two upright legs, at the lower end of which the running wheels are provided and the upper ends of which are connected to the first guide, wherein the upright legs are provided on the sides remote from each other of the two longitudinal walls. In this way a straddle carrier-like construction which extends over the stock of feed and the longitudinal walls can be obtained. The advantages of such a carrier can also be obtained if use is made of conveying means not configured with pressure means or at least not with pressure means specifically configured for conveying feed loosened by the loosening element from the loosening element through the pressure pipe of the pressure means in the direction of a processing location via the suction nozzle of the pressure means directly the feed has been loosened. In general there is in that case provided a system for processing feed, comprising a loosening element for loosening feed from a stock of feed, two parallel longitudinal walls for retaining the stock of feed therebetween, moving means for moving the loosening element in the vicinity of the stock of feed, conveying means for conveying feed loosened by the loosening element to a processing location, wherein the moving means comprise a horizontally extending first guide, along which the loosening element is movable in a first horizontal direction of movement and wherein the moving means comprise a carrier provided with running wheels, wherein the first guide forms part of the carrier, which carrier has two upright legs, at the lower ends of which the running wheels are provided and the upper ends of which are connected to the first guide, wherein the upright legs are provided on the sides remote from each other of the two longitudinal walls.

If at least some, preferably all, of the running wheels are of the steerable type, it becomes possible in a relatively simple manner to move the carrier in a desired direction, for example to another stock of feed.

If use is made of a first guide as discussed in the foregoing, it may be very advantageous if the moving means are further configured for moving the loosening element in a vertical direction of movement relative to the first guide. During movement of the loosening element in the vertical direction of movement along a stock of feed, a section of feed can be loosened from said stock.

A reliable embodiment can be obtained if the moving means comprise a third guide along which the loosening element is movable in the vertical direction, which third guide is movable in the first horizontal direction of movement along the first guide. Such a third guide can be realised in the form of a telescope construction, for example.

According to a suitable embodiment, the loosening element is a milling element for milling off feed from the stock of feed.

Alternatively, or even in combination with the preceding embodiment, the loosening element may also be a cutting element or a sawing element for cutting or sawing feed from the stock of feed.

The loosening element is preferably configured for loosening a section of feed having a width ranging between 20 cm and 75 cm from the stock of feed. Such a width is relatively small, so that the diameter of the pressure pipe and the capacity of the pressure element can remain within bounds, which will keep the cost price of the system within bounds.

In particular if the system according to the invention is used with silage and if the system comprises a first guide as discussed in the foregoing, it may be advantageous if the system is provided with winding means comprising a roller for a tarpaulin for the stock of feed, which roller is rotatable about an axis of rotation which extends parallel to the first guide and which is connected to the first guide for being jointly moved above the stock of feed by the moving means of the first guide and of the roller. In practice, silage is as a rule covered with a tarpaulin. The use of the winding means obviates the need for separate operations for removing the tarpaulin from a stock of feed prior to the loosening of feed in the region of the stock of feed where the tarpaulin has been removed. The system furthermore makes it possible to initially cover the stock of feed with the tarpaulin.

The pressure pipe may advantageously comprise a pressure pipe portion that extends vertically upward from the suction nozzle, and as well as an at least substantially horizontal pressure pipe portion that extends from the upper end of the vertical pressure pipe portion. The horizontal pressure pipe portion may in that case extend at a level higher than the upper side of the stock of feed or of an adjacent stock of feed. The pressure element may in that case be provided in the angle between the vertical pressure pipe portion and the horizontal pressure pipe portion. This embodiment may be advantageous in particular if the pressure element is configured as a spiral fan, in which the direction of suction and the direction of blowing are oriented perpendicular to each other.

If the horizontal pressure pipe portion comprises two rigid, at least substantially horizontal sub-pressure pipe portions which are hinged together via a flexible sub-pressure pipe portion, the horizontal pressure pipe portion is enabled to follow the movements of the loosening element or of the vertical pressure pipe portion whilst the horizontal pressure pipe portion will nevertheless terminate at the same position, for example at the processing location, at the end opposite the vertical pressure pipe portion.

In order to prevent the horizontal pressure pipe portion from moving downward under the influence of the force of gravity, it may be preferable if the horizontal pressure pipe portion is maintained at the same level by bracing means or tie means, which bracing means or tie means are supported on a base member disposed beside the stock of feed.

If the horizontal pressure pipe portion comprises two rigid, at least substantially horizontal sub-pressure pipe portions which are hinged together via a flexible sub-pressure pipe portion as has been discussed in the foregoing, the bracing means or the tie means can engage the horizontal sub-pressure pipe portion on or at least near a flexible sub-pressure pipe portion.

The invention is in particular suitable for being configured as a multiple system, wherein parts of the system can be utilised more efficiently. Within that scope the system may comprise at least one further loosening element for loosening feed from the stock of feed or from another stock of feed, wherein the pressure means comprise at least one further pressure pipe, each of which at least one further pressure pipe(s) has a further end that connects to the at least one further loosening element.

The efficiency can be increased in particular if the pressure pipe and at least one of the at least one further pressure pipe(s) converge and have a common pressure pipe portion.

If a pressure element is provided downstream of the position or at the position where the pressure pipe and at least one of the at least one further pressure pipe(s) converge, the pressure element in question can be utilised for conveying loosened feed from the loosening elements associated with the pressure pipe and the respective at least one further pressure pipe.

A very practical embodiment can be obtained if the system comprises, at the processing location, a device for mixing feed loosened by the loosening element and conveyed by the conveying means, which mixing device is provided with a container with a mixing element disposed therein, wherein the pressure means are configured to transport the feed into the container.

In particular with a view to obtaining a fully automated system, the system may comprise a buffer container at the processing location, in which the loosened feed is temporarily stored, wherein the system further comprises metering means for the metered supply of the loosened feed from the buffer container to a mixing device.

The invention does not require that the transport of the loosened feed from the loosening element up to the mixing device takes place entirely under the influence of the pressure means, although this may certainly be advantageous. It is also possible, for example, for the last part of the transport of the loosened feed to take place by means of a conveying system of a different type, for example by means of a belt conveyor. Within this framework a further embodiment of a system according to the invention is characterised in that the conveying means comprise at least one further conveyor downstream of the pressure pipe for conveying the loosened feed to the processing location, which further conveyor comprises a conveyor belt, for example, and/or a screw conveyor for conveying the loosened feed thereon/therewith.

The invention further provides a method for operating a system according to the invention as discussed in the foregoing. The method comprises the steps of

the moving means moving the loosening element along a stock of feed, during which movement feed is loosened from the stock of feed by the loosening element,

the pressure means sucking up the loosened feed and transporting it to a processing location via the pressure pipe.

If the system is configured with winding means, as discussed in the foregoing, the method may further comprise the steps of the moving means moving the loosening element along the stock of feed in such a manner that the loosening element loosens a vertical section of feed from the stock of feed,

the moving means moving the loosening element by a stroke length in the direction of the stock of feed and perpendicular to the vertical section of feed, during which movement the winding means wind up a tarpaulin that lies on the stock of feed,

the moving means moving the loosening element along the stock of feed in such a manner that the loosening element loosens a next vertical section of feed from the stock of feed.

If the system is configured with a mixing device, as discussed in the foregoing, the method may further comprise the successive steps of

the conveying means conveying the loosened feed into the container,

- the mixing element mixing the loosened feed in the container,

moving the mixing device to the location of cattle,

feeding the mixed feed to the cattle from the container.

In order to decrease the manpower that is required it may be preferable if the moving of the mixing device to the location of the cattle takes place in an automated manner.

For process reasons it may furthermore be advantageous if the conveying of the loosened feed to within the container by the conveying means takes place in two stages, wherein the loosened feed is temporarily stored at a buffer location between the two stages.

The invention will now be explained in more detail by means of a description of possible embodiments of the invention, in which reference is made to the following figures:

Figure 1 is an isometric view of an embodiment of a system according to the invention;

Figure 2 is a front view of the system of figure 1 ;

Figure 3 is a side view of the loosening unit as forms part of the system shown in figure 1 ;

Figure 4 is a side view of a carrier of the system; Figures 5a and 5b show a part of the system of figure 1 configured with an alternative loosening unit in vertical longitudinal section at two successive moments during use of the system;

Figure 6 is a side view of the alternative loosening unit;

Figures 7a and 7b show the detail VI I in figure 6 in two successive positions during use of the system;

Figures 8a and 8b are a top view and a side view, respectively, of an alternative embodiment of the system according to the invention;

Figures 9a and 9b are side views of another alternative embodiment of the system according to the invention during different stages of the use thereof.

Figures 1 and 2 show two identical trench silos 1 , 2, which are arranged beside and parallel to each other. The trench silos 1 , 2 each have a concrete floor 3, two concrete longitudinal walls 4 with a length of typically 40 m and a transverse end wall 5 with a length of typically 12 m. The floor 3 continues at the outer side of the longitudinal walls 4, for example over a width b of 0.5 m. In the silos 1 , 2, silage 6, 7 is stored. The silage 6 may be grass, for example, and the silage 7 may be silage maize. The filling of the trench silos 1 , 2 has taken place at a previous stage by means of vehicles that were driven into the trench silos 1 , 2 via the open front side opposite the end walls 5.

The system comprises a straddle carrier 1 1 for each trench silo 1 , 2.

The straddle carriers 1 1 each have two legs 12, which are connected at their upper ends via two steel sections 14, 15 which extend spaced from and parallel to each other. Seen in cross-sectional view, the sections 14, 15 have a horizontal H-shape, with two flanges which are centrally interconnected via a web. The two legs 12 of each straddle carrier 1 1 extend on the outer sides, or in other words, on the sides facing away from each other, of the longitudinal walls 4 of the associated trench silo 1 , 2. The legs 12 each have a girder 16. The girders 16 each support three uprights 17, 18, 19. The sections 14, 15 are supported on the uprights 18, 19. Each one of the girders 16 is itself supported by two running wheels 20, 21 , which are connected to bearing units 22, 23 for rotation about their central axis, which bearing units are in turn connected to the associated girders 16 at opposite ends thereof for pivoting about vertical pivot axes 24, 25. Driving means (not shown) are provided for pivoting at least two of the bearing units 22, 23 about the associated pivot axes 24, 25, so that the associated running wheels 20, 21 are of the steerable type. The running wheels 20, 21 are supported on the floor 3 of the associated trench silo 1 , 2 insofar as said floor 3 extends on the outer side of the associated longitudinal walls 4. I n order to ensure that the straddle carriers 1 1 will run parallel to the longitudinal walls 4 during use of the system, a guide (for example a gutter-shaped guide) may be provided in or on the floor 3, in which guide the running wheels 20, 21 can roll.

Each straddle carrier 1 1 comprises a winding body 81 which is supported at the ends thereof on two uprights 17 associated with the two legs 12 of each straddle carrier 1 1. The winding body 81 is provided on the side of the guide 14, 15 that faces the end wall. Wound around the winding body 81 is a tarpaulin 82, insofar as said tarpaulin 82 does not lie on the associated silage 6, 7. The winding body 81 can be rotated about its own central axis by drive means (not shown). On its upper side, the tarpaulin 82 is provided with channels 83 extending in the longitudinal direction of the trench silos 1 , 2, which channels can be filled with a liquid, such as typically water, for increasing the weight of the tarpaulin 82 and thus ensuring a good contact between the tarpaulin 82 and the silage 6, 7.

On their outer sides, the longitudinal walls 4 are provided with horizontally extending angle sections 90 along the entire length of the longitudinal walls 4. In the horizontal part 91 (see figures 7a and 7b) of these angle sections 90, which extend away from the associated longitudinal walls 4, engaging holes 92 are provided at regular intervals of 25 cm. Each girder 16 of the straddle carriers 1 1 comprises a shark-fin-shaped engaging means 93, which is capable of engaging in one of the engaging holes 92, as shown in figure 7a. Each engaging means 93 is provided for pivoting about the pivot axis 94 relative to the slide body 95. The slide body 95 is provided at the end of the piston rod 96 of the cylinder 97. The cylinder housing 98 of the cylinder 97 is rigidly connected to the girder 16. Operation of the cylinder 97 makes forward and backward movement of the slide body 95 in the longitudinal direction of the associated girder 16 possible. The slide body 95 is provided with a tension spring 99, which is fixedly connected to the slide body 95 itself at one end and, at the opposite end, to an arm 100 which is rigidly connected to the engaging means 93 and which can thus only pivot jointly with the engaging means 93 about the pivot axis 94.

Figure 7b shows the situation in which, starting from the situation shown in figures 7a, the slide body 95 has been extended along part of a maximum stroke length. Because of the convex side of the shark-fin-shape of the engaging means 93, the engaging means 93 has pivoted downward about the pivot axis 94, as a result of which it is now positioned underneath the horizontal part 91 of the angle section 90 in its entirety. The tension spring 99 is thereby loaded in tension, as a result of which the engaging means 93 will continue to press against the underside of the horizontal part 91. Once the engaging means 93 reaches the next engaging hole 92 upon further extension of the piston rod 96, the engaging means 93 will pivot back up again as a result of the action of the tension spring 99, causing the engaging means 93 to engage in the respective next engaging hole 92. Upon subsequent retraction of the piston rod 96, the associated straddle carrier 1 1 will be pulled in the direction of movement 101 over a distance equal to the stroke length of the cylinder 97, or more specifically, over the pitch distance between the two adjacent engaging holes 92. The process in question can then repeat itself. The straddle carriers 1 1 can thus be moved in steps along practically the entire length of the trench silos 1 , 2.

The sections 14, 15 on the straddle carriers 1 1 function as a guide 13 for a guide member 31. The guide member 31 extends between the two facing sides of the webs of the sections 14 and also between the flanges of the respective sections 14, 15 insofar as they extend between the two webs of the two sections 14, 15. To obtain an optimum guidance of the guide member 31 by the guide 13 as formed by the sections 14, 15, the guide member 31 may be provided with running elements and guide means, such as running wheels and guide wheels. The running elements may be supported on the upper sides of the lower flanges of the sections 14, 15, whilst the guide means are capable of guiding cooperation, for example under spring bias, with the webs or with the undersides of the flanges of the sections 14, 15. At least some of the number of running elements may be driveable in that case for moving the guide member 31 along with the guide 14, 15 over the entire width of the associated trench silo 1 , 2.

The guide member 31 supports a telescopic tube 29. The telescopic tube 29 comprises a fixed tube portion 32, which is fixedly connected to the guide member 31 and which extends at least in large part above the guide member 31 , and a movable tube portion 32 which can move up and down within the fixed tube portion 31 between a lower position, in which the movable tube portion 33 extends for the greater part underneath the guide member 31 , as shown in figure 5b, and an upper position as shown in figure 5a. To effect said up and down movement of the movable tube portion 33, two cylinders 34 are provided for each movable tube portion 33, the piston rod 36 of which engages the lower end of the movable tube portion 33 via a connecting element 38 and the cylinder housing 39 of which is connected to the fixed tube portion 32, near the upper end thereof, via a connecting element 41.

Provided at the lower end of the movable tube portion 33 is a loosening unit 51 (see also figure 3), which is connected to the tube portion 33 via a quick-action clamp coupling 60. The loosening unit 51 comprises a U-shaped saw blade 80. The legs of the U-shape have a length I of 25 cm, which length determines the thickness of the section of feed that can be cut from the stock of feed 6, 7 by the saw blade 80 during operation of the saw blade 80. The web of the U-shape, which connects the two legs of the U-shape, has a length of 75 cm. This length determines the width of the aforesaid section. Within the scope of the invention it may be advantageous if the length is less, for example also 25 cm, so as to thus reduce the risk of clogging. The loosening unit 51 also comprises drive means (not shown) for driving the saw blade 80. The loosening unit also comprises a suction nozzle 89 above the saw blade 80.

Depending on the nature of the feed 6, 7 it is also possible to use a different type of loosening unit, for example a loosening unit that is fitted with a cylindrical milling head 52 rather than with a saw blade. The loosening unit 51 ' shown in figures 5a, 5b and 6 comprises such a milling head 52, which is known per se and which is rotatable in the direction of rotation 54 about the axis 53. The axis 53 extends parallel to the longitudinal direction of the sections 14, 15. The rotation of the milling head 52 takes place via a driving motor (not shown). The milling head 52 is provided with milling teeth 56. The milling head 52 has a cutting half 52', whose milling teeth 56 move downward during rotation of the milling head 52 in the direction of rotation 54 about the axis 53 in use, and a displacing half 52", whose milling teeth 56 move upward in use. The loosening unit 51 ' further comprises a suction nozzle 55 between the movable tube portion 33 and the milling head 52, which nozzle is in communication with the interior of the movable tube portion 33. Precisely on the outer side of the milling teeth 56 in the lower half of the non-operative half 52', the loosening unit 51 comprises a curved shielding edge 57, which merges into a wall of the suction nozzle 55 at the upper side thereof.

At the upper end of the fixed tube portion 32, the system comprises a pressure element configured as a spiral fan 61 with an associated driving motor 62 for driving the blades in the fan 61 . The central suction side of the fan 61 connects to the upper end of the fixed tube portion 32. The fan 61 can thus create an underpressure in the suction nozzle 55 via the tube portions 32, 33.

A horizontal pressure pipe 59 consisting of two rigid, at least substantially horizontal sub-pressure pipe portions 63, 64, which are connected for hinging movement about a hinge 66 via a flexible sub-pressure pipe portion 65, connects to the pressure side of the fan 61 . The sub-pressure pipe portion 64 opens into a vertical collector pipe portion 67 and is also pivotally connected thereto for movement about the central axis thereof. The vertical collector pipe portion 67 is concentrically supported on the upper end of a mast 68 that is provided between the two trench silos 1 , 2, more specifically between the respective floors 3 thereof, in any case in such a manner that the facing legs 12 of the straddle carriers 1 1 associated with the two trench silos 1 , 2 can pass the tube 58 without impediment. To keep the pressure pipes 59 in a substantially horizontal orientation, the hinge 66 (in the case of the trench silo 1 ) is supported by a bracing rod 69, which itself is supported on the mast 68 at the end opposite the hinge 66. The connection between the bracing rod 69 and the mast 68 is such that the bracing rod 69 can pivot about the central axis of the mast 68. In the case of the trench silo 2, the hinge 66 is mounted to a tie rod 70, which, at the end opposite the hinge 66, engages the vertical collector pipe portion 67 at the upper end thereof and which is pivotally connected thereto for movement about the central axis thereof.

The suction side of a central fan 71 connects to the upper end of the vertical collector line portion 67, by means of which central fan 71 a relative underpressure can be created, via the vertical collector line portion 67, in the pressure pipes 59 associated with the two trench silos 1 , 2. A slightly downwardly sloping collector line portion 72 connects to the pressure side of the central fan 71 , which collector line portion extends over the trench silo 1 and which is supported by the support 79 on the side of the trench silo 1 remote from the trench silo 2 and which terminates at the suction side of a second central fan 73. Provided on the pressure side of the second central fan 73 is a discharge tube 74 that has an open bottom end. In figures 1 and 2 a conventional mixer feeder 75 provided with a tub 76 with rotatable vertical augers disposed therein is shown to be positioned under the open bottom end of the discharge tube 74.

The system as described in the foregoing, for example configured with a loosening unit 51 ', can be operated as follows. Because the straddle carriers 1 1 , 12 are movable and the guide members 31 with the loosening unit 51 ' provided thereunder are capable of being guided, it is possible to position the milling heads 52 directly above a section of the feed 6, 7 that is be milled off. Said section is located on the side of the feed stocks 6, 7 remote from the end wall 5. When subsequently the loosening unit 51 ' is moved downward whilst the associated milling heads 52 are rotated, the milling half 52' of the milling heads 52 (in particular the lower half thereof) will mill off feed from the stock of feed 6, 7 in question within said section. The loosened feed will subsequently be forced up into the suction nozzle 55 by the displacing half 52". From the suction nozzle 55, the loosened feed is transported through the successive pipes 29, 59, 67, 72 and 74 by the operation of the successive fans 61 , 71 and 73 and be deposited into the tub 76 of the mixer feeder 75. The mixer feeder will then mix and reduce the feed and move it to the cattle, where the feed can be presented to the cattle from the mixing tub by the mixer feeder.

In an alternative embodiment of the invention, the discharge tube 74 may not terminate above the mixer feeder 75 but above a further conveying system, for example a conveyor belt or a screw conveyor that extends into a cowshed or a feed kitchen.

It is also possible to make use of autonomous vehicles, possibly of the unmanned type, which drive across the floor 3 of a trench silo 1 , 2 in use. The vehicles may in that case be fitted with a loosening unit such as the loosening unit 51 or 51 ', to which a flexible pipe connects, which pipe terminates at a fan, such as the fan 73. The vehicles will in that case also comprise moving means by which the loosening element, such as the milling head 52 or the saw blade 80, of the loosening unit in question can be moved along the stock of feed 6, 7 for loosening feed therefrom. The loosened feed is then sucked in by the fan 73 and any intermediate fans. With such a system it is possible not to make use of the carriers 1 1 and the means needed for moving the carriers 1 1 .

Figures 8a and 8b show another alternative embodiment. In this case, too, two side-by-side trench silos 201 , 202 are provided. A first guide 203 extends transversely to the longitudinal direction of the two trench silos 201 , 202, which guide itself is movable in the longitudinal direction of the trench silos 201 , 202 and which to that end is supported at the ends thereof on the outer longitudinal walls 204 of the trench silos 201 , 202 via driven running wheels. A vertical pressure pipe portion 205, comparable to the pressure pipe 29, at the bottom end of which a loosening unit 206, for example comparable to the loosening unit 51 or 51 ', is provided, which loosening unit is movable in a direction transversely to the longitudinal direction of the trench silos 201 , 202 along the guide 203. The loosening unit 206 can operate both for silage 207 in the trench silo 201 and for silage 208 in the trench silo 202, wherein the bottom side of the loosening unit 206 must be movable to a height such that it will be positioned above the upper side of the two inner longitudinal walls 209 associated with the two trench silos 201 , 202.

A flexible pressure pipe 210 that terminates at the suction side of the fan 21 1 connects to the upper end of the pressure pipe 205. Provided on the pressure side of the fan 21 1 is a vertical discharge tube 212. The fan 21 1 is provided in the point of a symmetrical roof 213 of a cowshed 214 located beside the two trench silos 201 , 202. The flexible pressure pipe 210 extends in part over the roof 213 of the cowshed 214 so as to reach the fan 21 1 . The cowshed 214 has a central alley 215 with accommodations 216 for cattle 217 on either side thereof, which accommodations 216 are separated from the central alley by feeding fences 219. A mixer feeder 218 is provided in the alley 215. Feed as may come directly from the trench silos 201 , 202 after being loosened by means of the loosening element of the loosening unit 206 can be deposited into the tub of the mixer feeder as a result of the suction generated by the fan 21 1 via the discharge tube 212. The augers in the tub can subsequently mix the feed and, insofar as necessary, reduce it and subsequently spread it in the alley 215 along the feeding fences 219 in a manner that is known per se, so that it will come within reach of the cattle 217.

Figures 9a and 9b show another alternative system, which comprises two trench silos 301 , 302 oriented perpendicular to each other, near which trench silos a cowshed 303 comparable to the cowshed 214 is provided. A loosening unit 304 is provided for each of the trench silos 301 , 302, which loosening units are movable both in the longitudinal direction and in the transverse direction of the associated trench silos 301 , 302 and which are also movable in vertical direction, for example in a manner that will be apparent to the person skilled in the art after reading the above description. A flexible pressure pipe portion 305 is provided for each of the two loosening units 304, which pressure pipe portions converge in a common pressure pipe 306, which terminates at the pressure side of a fan 307 that is provided in the point of the roof 314 of the cowshed 303. The discharge tube 308 that connects to the pressure side of the fan 307 terminates directly above a mixing device 309. The mixing device 309 is suspended from a hoisting cable 310 that is passed over a winding drum 31 1 . During the filling of the mixing device 309, which is provided with a tub and with a vertical auger, the mixing device 309 has been lifted to a relatively high position just below the open end of the pressure pipe 306. The winding drum 31 1 is movable both in the longitudinal direction and in the transverse direction of the central alley 312 of the cowshed 303 by means of a guide system 313 that is suspended from the roof 314 of the cowshed 303. The mixing device 309 can be moved to the lower level of the cattle 315 in the cowshed 303 by operating the winding drum 31 1 , where it can release the feed mixed by the mixing device 309, which feed at least in part comes from the trench silos 301 , 302, to the cattle 315 in the immediate vicinity thereof.