GB2355710A - Cask filling and stoppering - Google Patents

Abstract

Apparatus for automatically racking and shiving casks 2, comprises a seat onto which the cask 2 is positioned with its bunghole 4 pointing upwardly, a racking tube 38 with a racking head 32 at its lower end which is inserted into the cask 2 through its bunghole 4, a means for inserting a shive 22 into the bunghole 4, a detector 18 which checks whether the bunghole 4 is correctly positioned in the bunghole 4 before the cask 2 is removed from the seat and a control unit. As described, the seat onto which the cask 2 is placed is a rumbler 64 comprising wheels 66, 68 which rotates the cask 2 until the presence of the bunghole 4 is located by a non-contact detector 18 which checks the position of the bunghole 4 beneath the detector 18. In the event that the bunghole 4 is not located beneath the detector 18, the cask 2 is rotated at a slower speed and in the reverse direction until the detector 18 locates the presence of the bunghole 4. The detector 18 measures the distance of a surface below it using a laser beam, or preferably a pair of laser beams whose lateral separation is slightly less than the diameter of the cask bunghole 4. The detector 18 used to detect the presence of the bunghole 4 may also be used to check whether the shive 22 is correctly positioned in the bunghole 4. The detector 18 means and the means for inserting the shive 22 are mounted on a rotatable arm 14 to enable them to be located in turn above the bunghole 4. Filling the cask 2 includes firstly pressurising the cask 2, then reducing the pressure in the cask 2 to a desired counterpressure value, slowly pumping beer into the cask 2 until the level of beer is above the racking head 32 and then pumping the beer into the cask 2 at an increased rate until the cask 2 is full. The pressure and conditions in the cask 2 are continually monitored and the rate of pumping beer into the cask 2 is set so as to minimize the formation of fob.

Description

2355710 CASK FILLING AND STOPPERIN The present invention relates to a

method and apparatus for filling and stoppering casks, and more particularly for carrying this process out automatically.

Unpasteurized beer is normally supplied by breweries to pubs and bars in stainless steel or aluminium casks. The casks are not initially pressurized, but internal pressure is generated as the beer continues to ferment inside the cask (a process known as "cask conditioning"). Casks are not to be confused with kegs, in which lager and pasteurised beers are normally supplied, and which are placed under internal pressure during pressure. This pressure is held inside the keg when the keg valves close.

Casks are normally filled through an opening (known as a bunghole) arranged approximately halfway up the body of the cask. Casks are routinely formed with rims projecting upwardly and downwardly from the body of the cask, and these rims serve as handles to allow the casks to be lifted and moved more easily. However, these rims are prone to damage, for example when the cask is dropped.

During filling (or "racking"), the washed cask lies on its side with the bunghole uppermost, in a suitable support arrangement to prevent it from rolling.

A racking tube is inserted into the cask, and fills the cask with beer. The tube is then withdrawn, and a stopper (known as a shive) is inserted into the bunghole. As the shive must remain in place during the build-up of internal pressure caused by fermentation inside the cask, it is essential to ensure that it is firmly seated in the bunghole. This is normally done manually by hitting the shive with a mallet or the like, to drive it fully into the bunghole. Routinely, two or three blows are delivered, to ensure the firm seating of the shive. The stoppering process is known as "shiving". The racked and shived cask is then removed from the support, and is ready for delivery.

It will be appreciated that this process is rather labour-intensive. The washed cask must be put on the support in the correct orientation, so that the filling tube can enter the bunghole. Following filling, the shive must be positioned manually, and then driven home with mallet blows. The filled and closed cask must then be removed from the support, to make way for the next washed cask. It will be appreciated that a considerable amount of effort must be exerted for each cask.

It would be desirable for this process to be automated. It is already known to use automated processes for washing the interiors of casks, and one such method is shown in GB 2180213. In the washing process, a washing device is inserted through the bunghole. The cask is positioned so that the central area, in which the bunghole is formed, is over the washing device. This is done by means of members which contact the end faces of the cask, rather than the rims, as the end faces are less prone to damage. The cask is then rotated so that the bunghole is pointing downwardly. The correct alignment of the cask is sensed by a sprung lever, which is arranged beneath the cask pointing upwardly. The lever is normally pressed against the side of the cask, but pops into the bunghole when the cask is aligned.

However, such a method of sensing the position of the bunghole cannot be used on a washed cask, as there is a chance of contamination of the cask by the sprung lever. Any contamination of the cask, and consequently of the beer which it is filled with, should be avoided.

According to a first aspect of the invention, there is provided a method of automatically racking and shiving casks, comprising the steps of positioning a cask with its bunghole pointing upwardly, inserting a racking tube with a racking head at its lower end into the cask through its bunghole, filling the cask, withdrawing the racking tube, inserting a shive into the bunghole, and checking whether the shive is correctly positioned in the bunghole before the cask is moved from its position, wherein the steps are carried out automatically under the control of a control unit.

The automation of the process allows casks to be filled more efficiently. In particular, the fact that the steps of positioning the cask, filling it, shiving it, and checking that the shive is correctly positioned all happen automatically at the same station allows the efficiency of the process to be improved.

Preferably, the step of positioning the cask is includes the steps of placing the cask on a rumbler beneath a non-contact detector whose position is preset, rotating the cask, detecting the presence of the bunghole beneath the detector, and stopping the rotation of the cask.

The use of a non-contact detector prevents cross contamination, which as mentioned above is highly undesirable.

The rotation of the cask can be stopped as soon as the presence of the bunghole is detected. However, as the casks have substantial rotational inertia, it is not normally possible to stop the cask immediately, and so it is likely that the bunghole will have been carried past the detector.

Thus, it is preferred that, after the rotation of the cask is stopped, the detector is used to check the presence of the bunghole beneath the detector, and in the event that the bunghole is not located beneath the detector, the cask is rotated at a slower speed and in the reverse direction until the detector detects the presence of the bunghole.

Any suitable type of detector can be used. For example, an optical recognition system can be used, which detects the presence or absence of the bunghole by 4 - analysis of a video signal or the like. However, it is preferred that the detector measures the distance of a surface below it. The presence of the bunghole below the detector can then be sensed easily, as the surface directly beneath the detector (whose distance is measured) when the bunghole is directly beneath the detector is the inside of the lower wall of the cask. It will be appreciated that the lower wall of the cask is a considerable distance further below the detector than the upper wall of the cask.

It is preferred that the detector uses a laser beam. In a particularly preferred embodiment, the detector includes two laser beams, whose lateral separation is slightly less than the diameter of a bunghole. This allows the bunghole to be positioned very accurately when both of the lasers give a reading indicating that they are sensing the inside of the lower wall of the cask.

The step of checking whether the shive is correctly positioned in the bunghole can be carried out by any suitable apparatus, such as an optical recognition system as described above. However, it is preferred that the step of checking whether the shive is correctly positioned in the bunghole is carried out by a detector which measures the distance of a surface beneath it.

If the shive is not correctly positioned, it will normally be standing proud of the surface of the cask, as a result of insufficient force being used to insert it, in which case the distance sensed by the detector will be too small. Further, if the shive is not accurately aligned then it cannot be inserted properly, and this will also result in the distance sensed by the detector being too small. It is not normally possible for the shive to be forced entirely through the bunghole, as the shive has a top ring whose diameter is greater than that of the bunghole. The fact that the distance sensed by the detector is not the expected distance shows that the insertion has not been successful.

Of course, separate detectors could be provided to sense the presence of the bunghole and to check whether the shive is correctly positioned in the bunghole.

However, for simplicity, it is preferred that the detector used to detect the presence of the bunghole is also used to check whether the shive is correctly positioned in the bunghole.

When filling the cask, it is very important to ensure that no foam (or "fob") is formed on the beer, as this cannot be removed. It is also of course necessary to ensure that the cask is fluid- tight before filling it.

In a preferred method, the step of filling the cask is includes the steps of pressurizing the cask, reducing the pressure in the cask to a desired counterpressure value, slowly pumping beer into the cask until the level of beer is above a beer valve of the racking head, and then pumping beer into the cask at an increased rate until the cask is full.

The initial pressurizing step ensures that the cask is fluid-tight. If it is not, then the pressurizing gas will simply escape. The steps of filling against a counterpressure and pumping beer in slowly until the level of beer is above the beer valve help to reduce the formation of fob.

Racking heads can normally be switched between the slow initial fill rate and a faster rate. The rate of beer flow is determined by the counterpressure, with a higher counterpressure resulting in a lower beer flow rate. The tendency for fob to be generated varies from beer to beer, and with beers where fob tends to form easily, it is necessary to fill slowly (ie to have a high counterpressure). However, in beers with a low tendency to form fob, the beer can be filled more quickly against a lower counterpressure.

In a preferred method of filling, the conditions inside the cask are continually monitored, and the rate of pumping beer into the cask is set so as to minimize the formation of fob. Preferably, it is the pressure in the cask which is continually monitored.

When fob forms, excess gas is generated inside the cask, and so the pressure inside the cask will change.

This change of pressure can be sensed, for example by a transducer, and the counterpressure in the cask increased to reduce the beer flow. If the pressure sensor shows that fob is not forming, then the counterpressure can be reduced, to increase the beer flow rate. If fob forms as a result, then the counterpressure can be increased again.

This method allows the casks tc be filled at an optimum speed with minimum formation. of fob.

is Indeed, this method is considered to be of independent inventive significance, and so according to a second aspect of the invention, there is provided a method of filling a cask using a racking head including the steps of pressurizing the cask, reducing the pressure in the cask to a desired counterpressure value, slowly pumping beer into the cask until the level of beer is above the racking head, pumping beer into the cask at an increased rate, continually monitoring the conditions inside the cask, and setting the rate of pumping beer into the cask so as to minimize the formation of fob.

According to a third aspect of the invention, there is provided apparatus for automatically racking and shiving casks, comprising a seat on which a cask may be positioned with its bunghole pointing upwardly, a racking tube with a racking head at its lower end which can be inserted into the cask through its bunghole, means for inserting a shive into the bunghole, detector means for checking whether the shive is correctly positioned in the bunghole before the cask is removed from the seat, and a control unit.

This apparatus allows casks to be racked and shived automatically, with a consequent increase in efficiency.

Preferably, the detector means also serves to check that the bunghole of the cask is pointing upwardly. This reduces the complexity of the apparatus.

The detector means can be fixed in position, and this has the advantage of simplicity. However, as the detector must be positioned above the bunghole of the cask in order to check that the bunghole is pointing upwardly and that the shive is properly inserted, it can obstruct the racking head, which must also be able to reach the bunghole. Thus, in a preferred embodiment, the detector means can be moved into and out of a position directly above said seat.

The detector means can be moved in any suitable manner. For example, they could be slid along a rail, although it is possible that an arrangement of this nature would lead to the rail obstructing the racking head. Thus, it is preferred for the detector means to be mounted on an end of an arm, whose other end is rotatably attached to a vertical shaft, the arm being driven to rotate around said shaft by a motor controlled by said control unit. This allows the detector means and the apparatus supporting them to be completely removed from the region above the bunghole.

The means for inserting a shive into the bunghole must also be positioned above the bunghole in order to insert the shive. For simplicity of construction, the means for inserting a shive into the bunghole are preferably also mounted on said arm. The main arm can then be rotated to move the detector means away from its position directly above said bunghole and to move the means for inserting a shive into the bunghole to a position directly above the bunghole.

Preferably, the detector can be moved back to its position directly above the bunghole after the means for inserting a shive into the bunghole has inserted the shive, to check whether the shive is correctly positioned in the bunghole.

In a preferred form, the seat for the cask comprises a plurality of wheels on which said cask rests, said wheels being rotatable to rotate said cask and to bring said bunghole into a position directly beneath said detector means when said detector means is positioned directly above said seat. The wheels can then be rotated to rotate the cask while the detector is actuated to sense the bunghole, and the wheels can be stopped when the bunghole is sensed.

Preferably, a pair of centring arms are provided at the seat, said arms being movable towards and away from the ends of the cask when it rests on said seat to centre it. This ensures that the cask is properly centred on the seat, and improves the reliability of the system.

A preferred embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a front view of the apparatus, with the racking heads in their parked positions; Figure 2 is a side view of the apparatus; Figure 3 is a rear view of the apparatus, with one of the racking heads in its racking position; and Figure 4 is a schematic plan view showing the centring apparatus As can be seen from Figure 1, the apparatus 10 includes a central vertical shaft 12. On this shaft 12 is rotatably mounted a main arm 14. This arm can be driven to rotate about the shaft by -means of a servomotor 16 mounted at the top of the shaft, which drives the arm through a gearbox. The gearbox has minimum backlash, generally of less than 3 arc minutes, to ensure that-, the arm 14 can be reliably positioned.

In a particularly preferred form, the servomotor is a Lenze MDSKA 100-22 frame size natural ventilation asynchronous motor, controlled using a Lenze 9325 drive system. The gearbox is a ZF-Servoplan type PG500.

Mounted on the free end of the arm 14 is a detector 18, which can be used to sense the distance of a surface positioned beneath the detector 18. The detector uses two sensors, each of which uses a semiconductor laser to generate an infrared laser beam having a wavelength of 780 nm. The beam is reflected from the surface beneath the sensor, and the reflected beam is detected and analyzed to find the distance of the surface beneath the sensor. Each sensor can be used to measure distances of up to 400 mm, at a resolution of 50 ym. Other types of laser can be used if a very wide range of cask sizes are to be handled by the apparatus. Laser detectors of this nature are more commonly used in gauging electronic equipment, for example by checking the number of pins on an IC package or measuring a thickness.

In a particularly preferred form, each sensor is a type LB-301 detector, manufactured by Keyence Corporation.

The laser beams have a lateral separation of slightly less than the diameter of a bunghole 4 of a cask 2. For example, when the apparatus is used to rack and shive casks having a bunghole with a diameter of 50 mm, the lateral separation of the laser beams can be around 45 mm to 48 mm. With such a small separation, it is possible for the reflected beam emitted by one of the sensors to be detected by the other sensor, and this would mean that the distance beneath the sensor was measured incorrectly. Although the error generated is small, it is preferable to avoid it if possible. One way around this problem is for the sensors to operate alternately, and in a preferred form the operation of the sensors alternates at around 30 Hz.

Also arranged at the free end of the arm is a shiving device or shiver 20, which is used to insert a shive 22 into the bunghole 4. In the preferred embodiment of the apparatus, the shiver 20 includes a pneumatic cylinder 24, which has means for retaining a shive 22 on the lower end of its piston. The lower end of the piston can be positioned above the bunghole 4 of a cask 2 by rotation of the main arm 14 and by raising and lowering of the cylinder 24. The pneumatic cylinder can then be actuated to drive the shive 22 into the bunghole 4.

In the preferred embodiment shown in the Figures, the means for retaining the shive 22 on the lower end of the piston of the pneumatic cylinder 24 is a vacuum gripper. This allows the shive to be retained with a predetermined force.

A shive feeder is also connected to the shaft 12.

The shive feeder is positioned such that the shiver 20 can be rotated to a position directly above it, and lowered to pick up a shive from the feeder using the vacuum gripper. Once a shive has been picked up by the vacuum gripper, a new shive takes its place. The feeder can take any suitable form.

In Figures 2 and 3, the shiver is shown in full lines in the position where it can take a shive 22 from the shive feeder (not shown). In Figure 1, it is shown in that position in dotted lines (as it is obscured by the central shaft 12). It is also shown in dotted lines in its shiving position, where the shive is held above the bunghole of a cask.

Arranged above the central shaft 12, in the shape of a 'IT", is a racking head support bar 30. A racking head 32 is pivotably attached at each end of the support bar 30, and these racking heads 32, which are generally identical, will be described in more detail later. The support bar 30 is supported at its ends by two support frames 34, which are attached to the central shaft 12 by struts 36, to ensure that the overall structure is sufficiently stiff to ensure that the various parts of the apparatus remain in their desired positions.

As mentioned above, the racking heads 32 are pivotably attached to the ends of the support bar 30.

Each racking head is positioned at the lower end of a racking tube '38, which is arranged in a frame. Side bars 40 are arranged parallel to the tube 38, and these side bars 40 are attached to the support bar 30 near their upper ends. As best shown in Figures 1 and 3, the ends of piston rods 42 of pneumatic cylinders 44 are attached to the top ends of the frame side bars 40, and these cylinders 44 can be actuated to pivot the frames.

In the retracted position of the pistons 44, the frames (and thus the racking tubes 38) are substantially vertical, and this is referred to as the racking position (see the left-hand side of Figure 3). Each frame also include pneumatic cylinders 46, which allow the racking head 32 at the lower end of the racking tube 38 to be moved up and down when the frame is vertical.

When the pistons 42 of the cylinders 44 are extended, the frames are rotated about their pivot point, so that the racking tubes 38 are moved out of the vertical, into a parked position, in which they point away from the central shaft 12 (see the right-hand side of Figure 3).

Each racking tube 38 includes a main beer supply line, a line for supply of pressurized air, and a return line for air, fob, and excess beer. The lines can be closed by valves, and the return line has a conductivity probe disposed in it, whose purpose will become clear later. In addition, a seal 48 is disposed around the racking tube.

Arranged below the frames supporting the racking heads 32 are guide means 50 for casks 2, which ensure that the casks which are to be filled follow predetermined paths. Again, each guide means is substantially identical, and so only one will be described. The means 50 comprises two inclined planes 52, 54, each of which is formed by two rails along which the cask 2 can roll. One of the inclined planes (52) leads towards the region beneath the support bar 30, and one (54) leads away from it. At the end of the first inclined plane 52 are two rockers 56, which can be driven to rotate simultaneously by a cylinder. The rockers each have a central recess 58, sized to accommodate a cask 2, between a pair of arms. The arms which the cask hits after rolling down the inclined plane are referred to herein as "catching arms". A similar pair of rockers 62 is positioned at the end of the second inclined plane 54. The rockers act as escapements, only allowing one cask through at a time.

Between each pair of inclined planes is a rumbler 64. This device is designed to rotate the cask to ensure that it is in the correct orientation for the racking and shiving operations. The rumbler 64 includes two pairs of wheels G6, 68. All of the wheels are the same size, and each pair is mounted on a common axle.

The axles are connected by a chain extending around equal-sized sprockets, so that when one of the pairs of wheels is driven to rotate, the other pair also rotates at the same speed and in the same direction The motors for driving the rumblers 64 are preferably mounted some distance above the rumblers, and drive them by means of a belt drive or the like. The reason for mounting the motors above the rumblers is to reduce the risk of spilt beer interfering with them. it will be appreciated that beer can easily be spilt during the filling process, and any such spilt beer should be kept as far away as possible from electrical equipment such as motors and switchgear.

When a cask 2 is placed on the rumbler G4, it rests in the gap between the two pairs of wheels 66, G8. When one pair of the wheels is driven to rotate, for example in an anticlockwise direction with respect to Figure 2, the cask 2 is driven to rotate in a clockwise direction. By controlling the rotation of the rumbler wheels 66, 68, and stopping the wheels in a particular position, the cask 2 can be put into any desired position. The wheels of the rumbler all have rubber tyres, to increase the friction between the wheels and the cask.

Beneath the rumbler 64 is a transfer member 70.

This can be moved upwardly to push the cask 2 up and off the rumbler. When a cask is pushed in this manner, it rolls onto the second inclined plane 54, to the second set of rockers 62.

Associated with each of the rumblers is a centring device 72, best shown in Figure 4. Each centring device 72 consists of a pair of centring arms 74, each of which carries a rotatable buffer 76 at one end. The centring arms 74 are pivotably mounted so that the buffers 76 can be moved towards and away from a cask 2 when one rests on the wheels 66, 68 of the rumblers 64.

Each of the centring arms is connected via a linkage 78 to a pneumatic or hydraulic cylinder 80.

When the cylinder 80 is actuated, each of the arms 74 is moved by the same amount, and so the buffers move 76 through the same distance. Actuation of the cylinder 80 allows the cask 2 to be accurately centred on the rumbler 64, as the buffers 76 contact the rims of the cask 2.

Although the cylinder and the linkage are shown as being arranged below the rumbler, it is preferred that they be arranged above the rumbler, to avoid any problems arising from beer being spilt on them.

Arranged directly above the rumblers 64 on the support bar 30 are photocells or similar sensors. These sense the presence or absence of a cask 2 on each of the rumblers 64.

The apparatus also includes a control device (not shown), which controls the various motors for the main arm 14 and the rumblers 64, the pneumatic cylinders 24, 42, 44, 80, and the valves and pumps for the racking heads. The control device also receives data from the detector 18 and the photocells.

The various dimensions of the apparatus are set to ensure that the casks can correctly positioned for racking and shiving. In particular, the distance from the centre of the vertical shaft 12 to the centre of the rumbler 64 (ie the point which is midway between the axles and midway between the edges of the wheels) is the same as the distance from the centre of the vertical shaft 12 to the detector 18. This is also the distance from the centre of the vertical shaft 12 to the centre of a shive 22 held on the shiver 24 by the vacuum gripper. In addition, when a racking tube 38 is in its vertical position, the distance from the centre of the vertical shaft-, 12 to the centre of the racking tube 38 is also the same as this distance.

The operation of the apparatus 10, and more particularly, the cycle of operations involved in the positioning, racking and shiving of a single cask 2, will now be described.

As a first step, a washed cask is placed on the upper end of the inclined plane 52. This may be done manually, or the casks may be received from an automated washer. The cask 2 rolls down the inclined plane 52, and hits the catching arms 60 of the first pair of rockers 56. The cask 2 comes to rest in the recesses 58 of the first pair of rockers 56.

When the various sensors indicate that the rumbler 64 does not have a cask on it, and the transfer member 70 has been retracted, the rockers 56 are rotated clockwise (as shown in Figure 2) about their axes, so that the catching arms 60 slope downwardly from the recess 58. Once this position is reached, the cask 2 rolls down the catching arms 60 to the rumbler 64. The distance between the first pair of rockers 56 and the rumbler 64 is such that the momentuat of the rolling cask is sufficient for it to roll over the first pair of wheels 66 of -the rumbler 64, but not. the second pair 68. As a result, the cask comes to rest between the pairs 66, 68, supported by both pairs of wheels. The presence of the cask in this position is sensed by the photocell. The cask 2 is shown in this position in Figure 2.

The rumbler 64 is then activated to rotate the cask around its centreline at relatively high speed (approximately one revolution per SE=nd). The cylinder 80 operating the centring arms 74 is then actuated, to bring the centring arms 74 towards the ends of the cask. As a result of the linkage 78 connecting the cylinder 80 and the centring arms 74, each centring arm is moved inwardly by the same amount. The rotatable buffers 76 on the end of the centring arms 74 contact the rims at the ends of the cask 2, and serve to centre it on the rumbler 64.

The main arm 14 is then rotated to bring the detector 18 into its detecting position, directly over the centre of the rumbler 64. As mentioned above, the detector 18 senses the distance between it and a surface below it. After a time sufficient to ensure that the cask 2 has completed a full rotation and is centred on the rumbler 64, the detector is activated to measure the distance of the surface beneath it.

As the cask 2 is generally cylindrical, the distance between the detector 18 and the surface of the cask will not vary greatly as the cask rotates.

Obviously, dents and so on in the cask will affect the distance measured, but they will only change the measured distance by a few centimetres at most. A change in distance of this order is ignored by the detector at this stage.

However, when the rotation of the cask 2 brings the bunghole 4 beneath the detector 18, the change in measured distance is much greater. When the bunghole 4 is directly beneath the detector 18, the distance measured is the distance to the lower wall of the cask 2, as the detector "sees through" the bunghole. Thus, the change in measured distance is approximately the diameter of the cask 2, and so the presence of thebunghole is sensed by the detector.

However, as a result of the rotation of the cask 2, the bunghole 4 is carried past the detector 18 quite quickly. As there is considerable inertia in the rumbler 64 and the cask 2, it is not possible to stop the rotation of the cask immediately the presence of the bunghole 4 is sensed, and have the bunghole positioned directly beneath the detector 18, as is necessary for accurate racking and shiving. Instead, a signal is sent to the rumbler 64, making it reverse the direction of rotation of the wheels 66, 68 and rotate more slowly.

The cask 2 is now rotated back to the position where the bunghole 4 is beneath the detector 18, but at a much slower speed. When the detector 18 senses that the bunghole 4 is beneath it, a signal is sent to the rumbler 64 ordering it to stop rotation altogether. Of course, if the cask overruns again, then the step of reversing rotation and rotating more slowly is carried out again, until the bunghole is located accurately.

In the preferred embodiment described above, where the detector 1.8 includes two laser beams whose separation is slightly less than the diameter of the bunghole, the cask can be positioned very accurately. When the distance sensed by both of the laser beams indicate that they are "seeing through" the bunghole 4 to the lower wall of the cask 2, then the bunghole is correctly located.

After a short delay, to ensure that the rumbler wheels 66, 68 and the cask 2 have stopped moving, the detector readings are checked again, to ensure that the cask has been positioned correctly. If necessary, the cask can be rotated slightly at this point to ensure that it is correctly positioned.

It may be that the detector 18 fails to detect the presence of a bunghole in the cask. For example, if one of the rims of the cask has been badly damaged and is shorter than the other rim, then when the cask is centred by the centring arms 74, the bunghole 4 may be excessively laterally offset from the position of the detector 18. In this case, the detector would not be able to detect the bunghole. If the detector fails to detect the presence of a bunghole, then an alarm can be sounded to alert the operator that the cask cannot be filled automatically, and the cask will be rejected.

This can be done automatically; alternatively, the operator could remove the cask by hand.

once the cask 2 has been positioned, the main arm 14 is rotated to move the detector 1-8 away from its position above the cask 2. When the detector 18 has been moved, the racking tube 38 is pivoted from its parked position to its racking position so that the racking head 32 is directly above the bunghole 4. Of course, as the position of the racking head 32 is fixed relative to the apparatus, it is vital that the cask 2 and the bunghole 4 be correctly positioned, to ensure that the racking head 32 can enter the cask 2. The racking tube 38 is pivoted by means of the pneumatic cylinders 44, and a reed switch senses when the racking tube 38 is in its correct racking position.

The racking head 32 is then lowered into the cask 2 through the bunghole 4, until the head is just above the lower wall of the cask. This is achieved using pneumatic cylinders 46, and a reed switch senses when the head 32 is in its proper position.

As the head 32 is lowered, the seal 48 on the racking tube 38 abuts against the surround of the bunghole 4, and is deformed by downward pressure, to ensure that a good seal is obtained.

Before the cask 2 is filled, it is pressurized up to around 15 psi (103 kPa). The exact pressure to which the cask is pressurized can be preset by the operator.

The pressure in the cask is sensed by a pressure transducer in the fob return line of the racking head, and when the preset pressure is reached a gas back pressure valve is closed. The pressurization is done to check that the cask is sound, and has no cracks or the like. In addition, when a cask is washed, it is necessary to remove a stopper from one of its faces (a so-called "keystone"), and the pressurization allows an automatic check that the keystone has been replaced.

obviously, filling a cask without a keystone in place will result in serious spillage of beer. The pressurization also allows the integrity of the seal between the seal 44 on the filling tube and the surround of the bunghole 4 to be checked.

Once the integrity of the cask and the seal has been checked, the pressure in the cask is reduced to the required counterpressure. The counterpressure determines the rate at which beer flows into the cask, and the lower the rate of beer flow the less tendency there is for fob to form. The counterpressure is set to suit the beer conditions, and will normally be between 6 and 10 psi (41 and 69 kPa). The pressure is reduced by opening the back pressure valve a preset amount to leak excess pressure away. The transducer senses when the desired pressure is reached, and the back pressure valve is then closed.

After a short delay, the beer valve in the racking head is opened, and beer is slowly pumped through the filling tube into the cask. The slow pumping further reduces the formation of fob in the cask.

once the level of beer in the cask is higher than the beer valve at the bottom of the filling head, the speed of beer pumping can be increased. The back pressure valve is opened to a preset amount to allow the excess air in the cask 2 to be vented through the racking tube 38. As an example, a nine-gallon (41 litre) cask can be filled in around 25 seconds.

A conductivity probe in the return line of the racking head senses when the cask is full. The probe is only activated by beer in the return line; air or fob in the return line does not activate it". When the probe is activated, the beer valve and the back pressure valve are closed. Of course, other means of sensing that the cask is full could be used, such as a pressure switch or beer volume metering.

After a short delay, the racking head 32 is withdrawn from the cask 2, and its fully retracted position is sensed by a reed switch. The racking tube 38 is then pivoted to its parked position.

It is then necessary to insert a shive 22 into the bunghole 4 of the filled cask 2. As a first step in the shiving process, the main arm 14 is rotated again to bring the shiver 20 over the shive feeder. The shiver is lowered, using pneumatic cylinders, until the vacuum gripper at the bottom of the shiver contacts the top of the shive 22. The vacuum gripper is then actuated to hold the shive 22 on the shiver 20. This part of the shiving process is done while the racking head 32 is still in the cask 2, and indeed the racking head 32 is not withdrawn from the cask until a shive 22 has been picked up by the vacuum gripper.

After the racking tube 32 has been put into its parked position, the main arm 14 is rotated to bring the shiver 20 directly above the bunghole 4. Once the shiver 20 is in place above the bunghole 4, it is lowered so that the bottom of the shive 22-is close to the bunghole 4. The shiver 20 is then actuated to drive the shive 22 into the bunghole 4.

As mentioned above, when shives are inserted manually, it is normally necessary to drive them home using several blows from mallets or the like. Thus, it is clear that a considerable force is required to drive the shive into the bunghole. In the current embodiment, the speed of approach of the shive must be relatively low to ensure that the shive is accurately positioned.

The insertion force, which is of the order of 500 N (an applied load of around half a ton), is supplied by the pneumatic cylinder 24 in the shiver 20, and this can be achieved using the type of pressurized air supply normally available in breweries. The cylinder 24 is actuated to drive the shive 22 home, and once this is done the vacuum gripper is deactivated.

The shiver 20 is then raised to its rest position, and the main arm 14 is rotated again to bring the detector 18 into its position above the bunghole 4. The detector is then used to measure the distance to the top of the shive 22, and the distance measured is compared to the distance that would be expected if the shive was driven fully home.

If the measured distance differs markedly from the expected distance, then the shive is not properly positioned. It is possible that the force exerted by the shiver 20 was insufficient to drive the shive fully home, and the shive 22 is projecting upwardly from the cask. In this case, the distance measured is slightly larger than that expected, as the top surface of the shive 22 is closer to the detector 18 than it should be, In addition, if the shive is not aligned sufficiently accurately with the burighole, then it will not be properly driven into position, and so the top of the shive will again not be the expected. distance from the sensor. This will again be sensed by the detector. if the shive is riot properly placed, then an alarm can be sounded to alert an operator that the cask 2 needs to be dealt with by hand.

If, on the other hand, the distance measured corresponds to the distance expected, then the shive 22 has been driven home properly. The filled cask 2 can then be moved from the rumbler 64. The centring arms 74 are retracted, and the transfer member 70 beneath the cask is raised to lift the cask frorv between the rumbler wheels 66, 68. After the transfer nt,,ember 70 has been raised past horizontal, the cask rolls down it and down the second inclined plane 54, and hits the catching arms of the second pair of rockers 62. The cask comes to rest in the recesses of the second pair of rockers, from where it can be removed by hand. Alternatively, the rockers can be rotated, like the first pair, to allow the cask to roll on to a further station.

The photocell is then used to check that the cask 2 has been moved from the rumbler 64. If the rumbler 64 is clear, then the next cask can be processed.

In the above description, the steps have been described sequentially. However, it. will be appreciated that some of 'the steps can be carried out simultaneously, to reduce the overall cycle time involved in racking and shiving a cask. For example, as mentioned, the step of picking up a shive 22 with the vacuum gripper can take place at the same time as the cask 2 is being filled, and indeed it is preferred that this is done, to ensure that a shive 22 is ready to be inserted as soon as the racking head 32 is withdrawn from the cask. This reduces the time during which airborne contaminants can enter the filled cask.

Further, it is preferred for a new cask to enter the apparatus, and be retained in the first pair of rockers 56, while an earlier cask is being filled. Then the new cask can be moved from the first pair of rockers 56 to the rumbler 64 as soon as the earlier cask is moved from the rumbler 64.

Further, the process was described with respect to a single rumbler and racking head. As is apparent from the drawings, one form of the apparatus includes two filling lines, each having a rumbler and a racking head, arranged on opposite sides of the main shaft. The operation of the second line is identical to that of the first.

However, as the apparatus only includes a single detector and a single shiver, mounted on the same arm, the lines must operate out of phase with each other. it is not possible for casks on both lines to be shived simultaneously, as there is only one shiver, and so a cask on one of the lines is shived (or positioned with its bunghole pointing upwardly, as this also requires the use of the arm) while the cask on the other line is moved to the rumbler, filled, or moved from the rumbler.

In practice, the routine is as follows. For clarity, the lines will be referred to as line A and line B, although it will be appreciated that there is no difference between the lines, and they are interchangeable.

Firstly, a cask is placed at the top of the first inclined plane of line A, and is transferred to the rumbler as described above. When on the rumbler, the cask is rotated, and the rumbler is controlled in combination with the detector to ensure that the bunghole is correctly positioned. Meanwhile, a cask is placed on the top of the inclined plane of line B, and is transferred to the rumbler.

The arm is then rotated so that the detector is positioned above line B. With the area above the cask on line A now free, the racking head is moved from its parked position to its racking position, and the racking process commences. At the same time, the cask on line B is rotated so that its bunghole is uppermost.

When the cask on line B is positioned, the main arm is rotated to bring the shiver over the shive feeder, and the vacuum gripper picks up a shiveThe racking head on line B is moved to its racking position, and the racking process commences. On line A, the racking head is removed from the cask and moved to its parked is position. The shiver is then brought over the bunghole, and the shive is inserted. The detector checks that the shive is fully home, and the cask is then moved by the transfer member onto the second inclined plane of line A.

The main arm is rotated to allow the shiver to pick up another shive. When the racking head of line B is moved to its parked position after the cask is full, the shiver is brought over the bunghole, and the cask is shived and checked as before. Meanwhile, a second cask is put onto the first inclined plane of line A, and transferred onto the rumbler. Once the filled cask on line B has been moved off the rumbler, the detector is brought over the new cask on line A, to position it, a new cask is put into line B, and the process continues as before.

In the embodiment described, there are two parallel filling lines, disposed on opposite sides of a central shaft which carries the detector and the shiver.

However, it is possible to use more than two filling lines, and this may be desirable in practice, as a greater number of filling lines allows more casks to be filled. A shaft as described above could be positioned between each pair of filling lines. Of course, other arrangements can also be used; for example, the detector and shiver can be supported on rails running above and perpendicular to the filling lines. Further, as the number of lines which can be served by a single detector and a single shiver is limited, more than one detector and shiver can be provided as necessary.

The racking head 32 used in the apparatus and process described above is a standard racking head, with a slow speed and a faster speed for pumping beer into the cask 2. The speed at which beer is pumped into the cask is determined by the counterpressure in the cask, and is dependent on the tendency for fob to form. As mentioned above, a nine-gallon cask can be filled by the racking head in around 25 seconds. However, a larger cask, such as an eighteen gallon cask, requires a longer time to fill, and thus slows down the overall cycle time. It is thus desirable for the casks to be filled as fast as possible while still avoiding fob formation.

In a preferred modification of the filling head, the faster speed at which beer is pumped into the cask is continuously variable. The pressure inside the cask is continuously monitored using the pressure transducer. Formation of fob inside the cask is accompanied by the breakout of gas from the beer, and so the pressure in the cask changes when this takes place. This change is detected by the transducer, and so the counterpressure is increased to reduce the speed of beer pumping, until a rate at which fob formation ceases is reached. Of course, if fob is not forming, then the speed of beer pumping can be increased. This can allow casks to be filled more quickly than with two speed (slow fill or faster fill) method discussed above.

Of course, it will be appreciated that various details of the apparatus used can vary without affecting the invention. For example, various means of supplying shives to the shiver can be used. Further, the casks can be transported in any suitable manner, and the guide means described above could be replaced by a walking beam or an indexing conveyor. In addition, the number of filling lines can vary, depending on the rate at which casks must be filled. The scope of the invention is thus not limited to the particular apparatus described above.

Claims (23)

1. A method of automatically racking and shiving casks, comprising the steps of:

positioning a cask with its bunghole pointing upwardly; inserting a racking tube with a racking head at its lower end into the cask through its bunghole; filling the cask; withdrawing the racking tube; inserting a shive into the bunghole; and checking whether the shive is correctly positioned in the bunghole before the cask is moved from its position; wherein the steps are carried out automatically under the control of a control unit.

2. A method as claimed in claim 1, wherein the step of positioning the cask includes the steps of:

placing the cask on a rumbler beneath a non-contact detector whose position is preset; rotating the cask; detecting the presence of the bunghole beneath the detector; and stopping the rotation of the cask.

3. A method as claimed in claim 2, wherein after the rotation of the cask is stopped, the detector is used to check the presence of the bunghole beneath the detector, and in the event that the bunghole is not located beneath the detector, the cask is rotated at a slower speed and in the reverse direction until the detector detects the presence of the bunghole.

4. A method as claimed in claim 2 or claim 3, wherein the detector measures the distance of a surface below it.

5. A method as claimed in claim 4, wherein the detector uses a laser beam.

G. A method as claimed in claim 5, wherein the detector includes two laser beams, whose lateral separation is slightly less than the diameter of a bunghole.

6. A method as claimed in any preceding claim, wherein the step of checking whether the shive is correctly positioned in the bunghole is carried out by a detector which measures the distance of a surface beneath it.

7. A method as claimed in claim 6 when dependent on any of claims 4 to 6, wherein the detector used to detect the presence of the bunghole is also used to check whether the shive is correctly positioned in the bunghole.

8. A method as claimed in any preceding claim, wherein the step of filling the cask includes:

pressurizing the cask; reducing the pressure in the cask to a desired counterpressure value; slowly pumping beer into the cask until the level of beer is above the racking head; and pumping beer into the cask at an increased rate until the cask is full.

9. A method as claimed in claim 8, wherein the conditions inside the cask are continually monitored, and the rate of pumping beer into the cask is set so as to minimize the formation of fob.

10. A method as claimed in claim 9, wherein the pressure inside the cask is continually monitored-

11. A method of filling a cask using a racking head, including the steps of:

pressurizing the cask; reducing the pressure in the cask to a desired counterpressure value; slowly pumping beer into the cask until the level of beer is above the racking head; pumping beer into the cask at an increased rate; continually monitoring the conditions inside the cask; and setting the rate of pumping beer into the cask so as to minimize the formation of fob.

12. A method as claimed in claim 10, wherein the pressure inside the cask is continually monitored.

13. Apparatus for automatically racking and shiving casks, comprising:

a seat on which a cask may be positioned with its bunghole pointing upwardly; a racking tube with a racking head at its lower end which can be inserted into the cask through its bunghole; means for inserting a shive into the bunghole; detector means for checking whether the shive is correctly positioned in the bunghole before the cask is removed from the seat; and a control unit.

14. Apparatus as claimed in claim 13, in which said detector means also serves to check that the bunghole of the cask is pointing upwardly.

15. Apparatus as claimed in claim 14, in which said detector means can be moved into and out of a position directly above said seat.

16. Apparatus as claimed in claim 15, wherein said detector means are mounted on an end of an arm, whose other end is rotatably attached to a. vertical shaft, the arm being driven to rotate around said shaft by a motor controlled by said control unit. 5

17. Apparatus as claimed in claim 16, in which said means for inserting a shive into the bunghole are also mounted on said arm.

18. Apparatus as claimed in claim 1.7, wherein said main arm can be rotated to move said detector means away from its position directly above said bunghole and to move said means for inserting a shive into the bunghole to a position directly above said bunghole.

is

19. Apparatus as claimed in claim -1.8, wherein said detector can be moved back to its position directly above said bunghole after said means for inserting a shive into the bunghole has inserted said shive, to check whether the shive is correctly positioned in the bunghole.

20. Apparatus as claimed in any of claims 15 to 19, wherein said seat comprises a plurality of wheels on which said cask rests, said wheels being rotatable to rotate said cask and to bring said bunghole into a position directly beneath said detector means when said detector means is positioned directly above said seat.

21. Apparatus as claimed in claim 20, wherein a pair of centring arms are provided at the Seat, said arms being movable towards and away from the ends of the cask when it rests on said seat to centre it.

22. A method of automatically racking and shiving casks substantially as described herein with reference to the accompanying drawings.

23. Apparatus for automatically racking and shiving casks substantially as described herein with reference to the accompanying drawings.