GB2083790A - (Un)stacking of goods e.g. bales - Google Patents

Abstract

A stacking machine comprises a bale receiving station (21) onto which bales are delivered lengthwise end to end. Successive pairs of bales are transferred transversely therefrom onto a layer forming station by a transfer member (32) and when a layer comprising at least a two by two array of bales, has been formed it is transferred, e.g. by a grap (134), to a stack-forming station, selected or alternate layers being rotated through 90 DEG during transfer. Pallets or containers may be provided at the stack-forming station for receipt of the stock. Unstacking comprises receiving a stack at the stack-forming station transferring each layer to the layer-forming station from where bales are transferred to the bale receiving station to be fed from the machine either singly or end to end to, for example, an automated animal feeding system. <IMAGE>

Description

SPECIFICATION improvements in or relating to the stacking of bales The invention relates to the stacking of bales and other rectangularly shaped objects.

It is present day practice to form stacks of bales with a machine fixed or towed behind a baler.

One form of machine to do this is the McConnel Balepacker, which forms stacks of 16 or 20 bales in the form of 4 or 5 piles of 4 bales and ties the stack thus formed with twine or string. The disadvantages of this method include the following: The continuous vertical splits or cleavage planes allows the penetration of rain down through the stack rather than restricting moisture to the outer surface of the stack. The stability of the stack is entirely dependant upon the string or twine surrounding it. Should the string stretch or the content of the bales settle as it cures, the cleavage planes open allowing moisture penetration or, the stack will tend to lean or parallelogram. Should the strings break due to stress during mechanical handling or transport, the stack becomes unstable and will collapse.A mechanical handling device specifically designed for this form of stack has to be used. Once the strings have been cut or have been broken the stack is unstable and can only be moved single bale by bale. It is not possible to pick up a part stack to produce a load or stack inside a building of less than multiples of four bale heights. It is not possible to windrowthe stacks in the field and a 20 bale pack is not large enough to fully exploit the lifting capacity of the rough terrain fork lifts and other mechanical handling devices which are increasingly being used. The weight of the machine and the bales in it can cause traction difficulties on soft, sloping or slippery ground.

Another form of machine to do this is the British Leley Cube 8 Accumulator. This method has the following disadvantages: The bales are all in contact with the ground during part ofthe stack forming process and can become contaminated with soil or their strings are liable to be cut or weakened by stones or flints. The stack size is limited by the inherent stacking method of two bales per layer and the four layered stack of 8 bales is not particularly stable or uneven or sloping ground. The stacks cannot be windrowed and are only of eight bales, which weigh only about 200 kg, so the lifting capacity of conventional tractor loaders and the greater lifting capacity of rough terrain fork lifts and other mechanical handling devices cannot be fully exploited.Because of the number of lifts required and the distance that the mechanical handling device has to travel it is not possible for one mechanical handling device or machine to clear the stacks of bales as fast as current balers can operate. The risk of weather or rain damage to the bales is thus increased.

An object of the present invention is to provide a method of and apparatus for forming bales into stacks comprising of layers which are self tied, these stacks and the method by which they are formed materially overcoming the above-described disadvantages.

According to one aspect of the invention, there is provided a bale stacking implement or machine comprising a chassis with a single axle or a close coupled or tandem axle arrangement that has wheelbase or distance from its axle to its drawbar hitch point that is roughly or as near as is practical to the distance between the baler axle and the baler's rear drawbar or hitch point, a bale receiving device along which the bales travel from the baler's bale chamber to the implements feed path even when the baler and implement are turning a corner, a bale feed path along which the bales are propelled by the balers expelling action end to end, a bale transfer device hereafter referred to as the push-over which transfers one or two or more bales to the layer forming platform or area with a sideways and/or vertical movement relative to the length of the bale or bales and the feed path, a layer forming platfprm or area hereafter refered to as the layer station in which two or more units of one or two or more bales transferred at each cycle of the push-over are accumulated either positioned side face to side face or positioned top face to top face to form a layer of bales, a layer grabbing or holding or clamping device or mechanism hereafter refered to as the grab which enables the complete layer of bales to be to transferred clear of the layer station to the load forming station, a layer transfer mechanism or motion to which the grab is attached and which transfers the layer of bales formed previously in the layer station to the load station where a stack of the required configuration is formed or built, this layer transfer mechanism or motion hereafter refered to as the stack-builder can be provided with a middle station if required at which the grab is held or wait when empty until the next layer of bales has been formed in the layer station and at which a layer of bales can be held or kept waiting until such time as a complete stack or part stack has been unloaded and at which middle station the the grab may be rotated about an axis perpendicular to the stacking face of the layer so that alternate or specific layers may be rotated relative to the layers that are not rotated so that a tied stack is formed or built in the load station and at which middle station the empty grab is de-rotated or rotated back to its primary alignment which coincides with the layers formed in the layer station, the load station already refer ed to above which consists of a framework, a floor or set of rollers upon which the first layer of the stack rests, side supports on two or more of the floor's sides which prevent the part built stack from being shaken apart by the implement or machine's motion over uneven or rough ground, a pivoting or lowering system which enables the load framework complete with its floor and sides to move between its load station whereat the stack is formed or built and its discharge station whereat a discharge mechanism propel Is the stack of bales out of the load compartment on to the ground, the rear of the floor being as close to the ground as is practical and the discharge mechanism having a motion or drive that propel Is the stack backwards with a velocity equal to or slightly greater than and opposite to the forward velocity of the machine or implement so that the stack of bales is deposited onto the ground as gently as possible to minimise the chances of any of the bales in the stack toppling from the stack, the general layout of the machine being such that it is as wide, or as near as it practicable as wide as the baler it is towed behind and because of the machines wheelbase and pivot position relative to the baler with the result that it follows or tracks behind the baler both when the baler is moving in a straight line and when the baler is turning a corner, the general layout of the machine also being such that it is relatively easy for the operator or tractor driver to reverse the tractor, baler and bale stacking machine, the general layout of the bale stacking machine also being such that its centre of gravity is slightly ' in front of its axle or tandem axle pivot point when the machine is empty of bales and when the stack builder or layer transfer mechanism is in its forward position with the result that a small downward force is applied to the baler's rear draw bar, the general layout of the bale stacking machine however being such that as a stack of bales is progressively built or formed in the load station the centre of gravity of the bale stacking machine and the bales therein moves progressively further rearwards and behind the axle with the result that an increasing upwards force is applied to the baler's rear draw bar and with the result that the downward force exerted by the baler's front draw bar upon the tractor's draw bar is increased as a stack of bales is progressively built or formed in the load station so that a weight transfer onto the tractor's rear or drive axle occurs and so that the tractive grip of the tractor's rear wheels is thereby increased, there is also provided a power system to operate the various movements and there is provided a control system either manual or partly automatic or fully automatic to operate the power system that operates the various movements.

According to a second aspect of the invention there is provided a bale stacking implement or machine which is rigidly attached to or forms an integral part of the baling machine, be it tractor drawn or self propelled, the bale stacking part of the combined baler and bale machine being povided with the feed path, layer forming station, stack-building or layertransfering motion, load station and discharge mechanism generally described in the first aspect above.

According to a third aspect of the invention there is provided a bale or other rectangularly shaped object stacking machine or mechanism comprising the feed path, layer forming station, stack-building or layer transferring motion and load station generally, but not neccessarily exactly, as described in the first aspect above but provided with ground supports such that it can be operated as a stationary machine.

Embodiments of this third aspect may be provided with the facility for integral or independant insertion of pallets or containers in the load station such that it thereby becomes a pallet or container stacking or filling machine, and may be further or alternatively provided with other operations or facilities such as wrapping, banding, product treatment, processing or finishing facilities.

According to a fourth aspect of the invention, there is provided either a bale or other rectangularly shaped object unstacking machine or a combined stacking and unstacking machine comprising generally but not exactly the feed path, the layer station, the layer transfer motion or mechanism and the load station described in the first aspect above and in addition comprising the neccessary reverse direction drive mechanism such that the invention can accept loads or stacks or palletised stacks or stacks in containers or similar and such that this fourth aspect of the invention can feed the bales either singly or in a stream end to end onto a conveyor or direct into a bale grinder, boiler or furnace, an automated animal feeding system or direct into any other processing or bale consumption system.An example of this fourth aspect of the invention is a bale stacking machine generally as described in the first aspect above for use in the harvesting season but with the ability to receive stacks of bales taken from storage by a mechanical handling device such as a rough terrain fork lift truck and with the ability to automatically feed them for consumption by livestock, for processing in a tub mill, hammer mill or similar machine or into a furnace or boiler for heat generation. Such a machine could be provided with the neccessary automatic controls such that it could feed the bales at the rate required by the machine or process chosen. It thus has the advantage of performing more than one operation and allowing the use of a low capacity process without an operator in attendance.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings, in which:- Figure 1 is a side elevation of a single axle trailing bale stacker in accordance with the first aspect of the invention, a number of parts or components being ommitted or simplified for the sake of clarity. In this Figure are shown bales in the feed path including two bales about to be pushed across into the layer forming platform which is behind these two bales and therefore not visible, a layer of bales, the end two being visible, is shown held by the grab in the middle station, the grab and transfer arms also being shown (in dashed lines) in the rear position over the load station.

Figure 2 is plan view of stacker shown in Figure 1, a number of parts or components being ommitted or simplified forthe sake of clarity. In this Figure bales are represented in heavy dashed lines, one having entered the feed path, two being pushed over from the feed path and coming into contact with six bales already in the layer forming station or platform, eight bales have been placed in the load station to form the first or bottom layer of the stack and the grab, shown schematically as a rectangular frame, is shown over the layerforming platform. The heavy dashidot line represents the outside or right hand edge of the layer of eight bales that will be formed when the two bales being pushed from the feed path have been pushed fully ont6the layer forming station or platform.

Figure 3 is a projection view, to a different scale, of a stack of fourty bales formed by the bale stacker as drawn in Figures 1 and 2, comprising five alternately rotated layers of eight bales. These bales having a length approximately equal to two and a quarter bale widths as drawn to give a more positive tie than if the baler had been set to produce bales with a length equal to two bale widths.

Figure 4 is a projection view, to the same scale as Figure 3, of a stack of fifty bales, comprising five alternately rotated layers of ten bales, which could be formed by a bale stacker generally as in Figures 1 and 2 but with a wider layer platform, grab, layer transfer mechanism and load station. Assuming the bales are produced by a baler with an eighteen inch wide bale chamber, which size is commonly used in England, the width of five edge to edge would be ninety inches in theory but is in practice found to be approximately ninety six to ninety eight inches, that is approximately eight feet -the load width commonly used in England for road transport. Assuming the baler is set for a maximum bale length of fourty eight inches, a square stack is produced by this embodiment of the invention.The control system of the stacker is such that the operator can unload alternate stacks of only four layers. The operator of a rough terrain lift truck equipped with a suitable grab or gripping devise could then load a fourtyfoot articulated road trailer with five stacks of four layers and five stacks of five layers to give a nine layer load which is in many instances the optimum load height. The resulting load would require the minimum of roping and would optimise the volumetric capacity of a fourty foot long articulated trailer.

Figure 5 is a projection view, to the same scale as Figure 3, of a stack of fourty eight bales, comprising four alternately rotated layers of twelve bales. Each layer consists of four rows of three bales end to end, the length of the bales being one and one third of a bale width. This stack configuration is shown to illustrate the versatillity of the invention. These stacks could be produced by the stacker shown in Figures 1 and 2, but with a modified grab assuming a hook type grab is used. Assuming the stacker is built to take the weight, silage crops could be baled, transported and ensiled using the same equipment used for hay and straw baling and transporting.

Figure 6 is a side elevation, to a different scale, showing the push over mechanism in greater detail in the raised position and, in dotted lines, are shown the push over bar and arms.

Figure 7 is a plan elevation, to the same scale as Figure 6, of the push over mechanism in the ready-to-push position and; in dash lines, the push over bar is shown in the push-over-completed position.

Figure 8, is a projection view, to a different scale, of a hook type grab for eight bales.

Figure 9 is a schematic sectional view from the front of the bale stacker, showing bales in the feed path and layer platform, the four positions of the push-over bar and its cyclic path, the layer made signal bar and embodiments for controlling the bales.

Figure 10 is a schematic section as in Figure 9 showing two embodiments, a side squeeze grab and a push-over bar system that operates from under the feed path and layer platform.

Figures 11 and 12 are a side elevation and overhead view in the direction 'A' respectively, to the same scale as Figure 1, showing embodiments of the bale stacker in Figures 1 and 2. In Figure 11 bales are shown in the feed path and in the grab which is in the middle position, a stack of fourty bales, drawn dash-dot-dot, is shown in the load station and the position of the layer of eight bales, drawn dash-dash, is shown in the transfered rearwards-ready to lower position. In Figure 12 bales are shown, drawn 'dash-dash', in the feed path, in the layer station and in the first layer of the load station.

In the following description, right hand and left hand references are determined by standing at the rear of the machine and facing in the direction of forward travel. Also, in the following description, it is to be understood that such terms as "forward", "left", "rearwards" "down", etc., are words of convenience and are not to be construed as limiting terms.

In General Referring now to the drawings, and particularly to Figures 1 and 2, there is shown a "single" axle trailer bale stacker, in accordance with the first aspect of the invention. The machine is provided with a mobile chassis consisting of a longitudinal channel 1, a transverse channel 2 (shown dotted as not visible), a triangulting channel 3, a box section 4 extending rearwards from 1 and a similar box section Son the right hand side extending from the junction of 2 and 3, both 4 and 5 terminating at the load station pivot point 6, rearward extensions 7 (left hand) and 7 (right hand) terminating at the secondary swing over arm pivot points 9 and 10, primary swing over arm pivot brackets 11 and 12, a pushover mounting frame consisting of uprights 13 and 14 and a longitudinal member 15, stub axles 16 and 17 attached to 4 and 5 respectively and on which wheels 18 and 19 rotate.

A drawbar hitch 20, attached to the front of 1, is used to tow the stacking machine. It is hitched to a draw bar which is attached to and situated below the rear of the baler's bale chamber, in such alignment that the bales enter the stacker's feed path. The baling machine, assuming that it is a conventional "pick-up" baler, is in turn hitched to an agricultural tractor. The tractor driver's tasks include observing that both baler and bale stacker are functioning correctly and controling any of the stacker's functions or movements that are not controled automatically by its automatic control system.In the prototype machine upon which the first aspect of this invention was based, the operator or tractor driver's only "control" function during normal operation is to decide the most suitable time to "unload" the stack of bales from the load station and then to lower the load station or chamber.

Afeed and layer forming platform or tray 21 is attached to the chassis an could be an integral or load bearing part of the chassis. A bridging plate (not shown) is attached to and below the rear of the bale chamber and is hinged so that it floats on the front upper surface of the feed path hereafter called the receiving section. The purpose of the bridging plate is to support the bales as they pass from the bale chamber to the feed path. Vertical posts 22 and 24 support a guide bar 26 on the left hand side of the bale feed path and a similar guide bar 27 and 29 (Figure 7) is attached to the front post 13 of the push-over mounting frame. These guide bars, and any other required guidance systems, serve to receive the bales from the baler even when a tight turn is being negotiated and to feed the bales down the feed path.To prevent the bales from sliding off line further down the feed path, when the bale stacker is traversing sloping ground, spring loaded hinged flap or flaps 28 (Figure 9) and quide bar 30 (also Figure 9) constrain the bales along the remainder of the feed path. When the required number of bales - 2 in this case - are sufficiently far down the feed path to be clear of fixed quide 29 attached to post 13 on the right hand side of the feed path, the push-over bar 32 moves from position P1 to P2 (see Figure 9) to move the bales from position F to position L1. After pausing in this position the pushover bar is lifted to position P3, swung back to position P4 and lowered to its start position P1 in time for the cycle to be repeated when the next 2 bales are ready to be pushed-over.The guide flap or flaps 28 are forced down by the bale and spring back up as the bales have passed over. During the next push-over cycle the bales in position L1 are pushed to position L by the bales moved from F to L1 and during the next two cycles the first pair of bales are pushed to L3 and then to L4. At this stage when four push-over cycles have been completed a layer of eight bales has been formed in the layer station and the bales in position 14 have forced the layer-made bar 34 from its normal spring held position 34N to the position as drawn in Figure 9. The movement of this bar is used to signal that a layer has been formed.An inherent advantage of the layer forming system is that the bales are held firmly together on their side edges, the rightwards force of the push-over bar being resisted by frictional forces and, on the last part of the fourth cycle, by a relatively strong spring which tries to keep the layer-made bar 32 in position 32N; The push-over mechanism will now be described in greater detail with reference to Figures 6 and 7. A front pivot arm assembly consists of an arm 34, a pivot shaft 36, hinge brackets 38,39,40 and 41, lift cylinder mounting arms 42 and 44, a tie-bar post 46 and tie bar pivot bracket 48. The assembly pivots about bearings 50 and 52 which are mounted on the push over mounting frame member 15.A rear pivot arm assembly consists of an arm 54, a pivot shaft 56, hinge brackets 58,59,60 and 61, a combined tie bar and push cylinder post 62 and, on this post, a tie bar pivot bracket 64 and a push cylinder pivot bracket 66. A tie bar 68 links the front and rear pivot arm assemblies and, as drawn, ensures that the two pivot arms remain parallel. A push-over cylinder 70, is mounted between the bracket 66 and a frame bracket 72 attached to the mounting frame member. A rear lift arm assembly consists of a main arm 74 and a support arm 76, a lift tie-bar post 78 and, on this post, a lift tie-bar pivot bracket 80. This lift arm assembly is mounted on the rear pivot arm assembly by means of pivot pins 82 and 84 and can thus pivot up and down.A similar front lift arm assembly, consisting of a main arm 86 and support arm 88, a post 90 and on this post a lift tie-bar pivot bracket 92 and a lift cylinder mounting bracket 94. The up and down motions of the two lift arm assemblies are syncronised by the lift tie-bar 96 and achieved by means of the lift cylinder 98. The push-over bar, generally 32, consists of a main bar 100, a rear bar 102, end plates 104 and 106 and two pivot bushes (not visible) between the two arms. A front push-over mounting assembly consists of a hinge bracket sub-assembly 108 and a post 110. A similar rear assembly consists of sub-assembly 112 and post 114. These two assemblies a mounted on the front and rear lift arm assemblies by means of pivot pins 116 and 118 respectively and the posts 110 and 114 pass through the push-over pivot bushes and thus mount the push-over bar 32.The push-over bar is prevented from detaching itself from the posts 110 and 114 by collars 120 and 124 respectively. The lift cylinder may or may not be assisted by a lift spring in tension between, say, the bracket 80 and a bracket on top of mounting frame member 13. The push cylinder may or may not be assisted by a tension spring mounted, say, on bracket 66 and a bracket fitted somewhere near the rear end of member 13 (these springs assisting in the lift direction and push directions respectively) Alternatively, single acting cylinders could be specified and the lower and push-over return motions could be achieved by means of springs.The push-over mechanism is sufficiently strong to push eight bales (two from position F and twd each at L1, L2 and L3) across the layer forming tray or station to complete the layer, overcoming friction and the return spring of the layer made bar 34 even when these bales have to be pushed up a slope because the stacking machine is operating on a hill.

Some features or characteristics of the push-over mechanism are not immediately obvious and will therefore be discussed. Bales issuing from a baler usually vary in length both from bale to bale and when the nature or condition of the material changes. The movement of the bales tend to be in a series of jerks, with pauses when no crop material is being picked up by the baler. When the baler is in good condition and properly adjusted the bales are uniform and staight and are not joined to each other with crop material. The mechanisms of a bale packer, however, should be able to cope with less than ideal bales, that is curved bales, ones that are spongy or soft, bales that are partly joined and ones with considerable variation in length. The push-over mechanism has a long push bar 32 to act on most of the length of the bales to be pushed. At the start of its movement it has a rearward component of velocity which is approximately equivalent to the greatest velocity imparted on the bales by the baler. The guides 26 and 27 have a parallel section that is set as near to the width of the bales as is practical to straighten any pronounced curvature. The right hand guide rear section 29 serves to prevent the bale adjacent to those being pushed over from moving out of alignment even if joining crop material resists bale separation. Any bale curvature induced in this adjacent bale during bale separation is countered by the fact that the push over bar pauses in the position P2 until the next bale has moved past its leading edge, and until the sloping left hand front edge 106 of the push bar has served to guide any curved bale back into line.Bale length variation can be accomodated because of the fact that the bale join can be anywhere between the rear corner of guide 29 and the front of the push bar 106. The mechanism as here described and drawn has proved adequate in tests but the following embodiments could if neccessary be included: the push bar could be provided with a extendable front section so that its length can be adjusted to suit field conditions, the push over motion could be initiated by a signal originating from the second bale joint passing the rear corner of guide 29 (this could be achieved by providing a step-down in the feed path tray at this point; as a complete bale passed this step it would drop and depress a signal lever or pad, the signal given by the first bale being blocked by second signal lever approximately three quarters of the way down the push-over section to ensure that the push-over would not be initiated before the required number of bales had entered the push-over section of the feed path).

Another feature of the preferred system is that it could be adjusted to accept bales of different width merely by providing sideways adjustment of guides 26 and 30 and a sufficiently long push-over stroke to accept the widest required design width and, if required, adjustable stroke limit stops for the narrower bales.

Similarly, the mechanism can accept bale height differences subject to sufficient bar lift being incorporated.

Broken bale strings can and do cause problems with existing bale handling devices. Tests to date indicate that this bale stacker will in many instances handle the stack bales with one defective string (in practice an inferior ball of string or a knotter defect will cause occasional bales to be produced. In these circumstances it is desirable to be able to carry on baling while a fitter is being summoned and while his or the operator's attempts to cure the fault are being tested so that the least possible interuption to bale production is incurred). However, it would would be possible to provide a spring loaded guide bar 30 so that a defective bale could be ejected to the left of the machine by returning the push bar directly from position P2 to P1 without lifting it.This reject stroke could be initiated either by the operator who could be standing adjacent to this part of the machine or seated in the Tractor, or could be initiated automatically by a string sensing device mounted over the feed path somewhere by the front upright member 13 of the push-over mounting frame.

Bales in the layer forming tray or station are constrained by the layer made bar 34 and guide bars at the front and rear of this tray, the front bar having an angled lead in section 126 (Figure 7). To date in tests fixed bars have proved satisfactory but the rear bar could be provided with adjustment or a spring loaded action if need be. When the machine is being operated along a slope (downward to the right), the bales first pushed into the layer forming station tend to slide down the tray to the right, to the detriment of the correct operation of the machine. Should the provision of small movement restriction ramps prove inadequate, a system of spikes 128, mounted on hinged arms 130 and actuated by rods 132 connected to the guide flap 28 could be provided (see Figure 9).

It should also be pointed out that by virtue of the design of the stacking machine in general and the layer forming system in particular, that the machine can be so dimensioned that it will be able to form layers (and hence stacks) smaller than the selected design maximum, either in the form of less bales or of bales of smaller width, length and/or height. This can be achieved by making one or more of the guides around the layer platform adjustable and/or by allowing the push-over stroke to be adjusted (position P2 being adjusted rightwards).

The layer transfer system will now be described. A completed layer of bales has to be removed from the layer forming tray before the next push over cycle is initiated. To this end, a grab (generally indicated as 134) is held by the layer transfer motion or mechanism somewhere above the layer station. When the layer made signal is made by the movement of the layer made bar 34, the grab 134 is lowered by means of a cylinder 136, its motion being guided by rods 138 and 140 sliding through guide tubes or bushes 141 and 142 (not visible), or by such alternative mechanism as will achieve the same objective, until the grab comes to rest on tpp of the layer.This movement is provided with more stroke than is required for the smallest bale height specified so that the clamp frame is forced onto the layer to hold it firmly while grab hooks 144, 146, 148, 150 etc. are forced into the bales by the grab cylinder 152 (see Figure 8). (the grab in itself is not considered to be novel).

The "grabbed" layer is then raised to the "middle" station, position M, Figure 1. It is here, according to the first aspect of the invention, that some or alternate layers are rotated to achieve a tied stack. This is achieved by the provision of a bearing housing 154 attached to the grab frame, a bearing shaft 156 (not visible) attached to the head plate or assembly 158 (Figure 1). (Alternatively, the bearing housing could be attached to the head plate 158 and the shaft 156 to the grab frame). The guide rods 138 and 140 are atached to this head plate, as is also the rod of the lift cylinder 136. The head plate's motion is restricted thereby to an up and down motion without any rotation. The grab can rotate relative to the head plate and, according to this aspect, a 900 rotation is achieved by means of a "rotate" cylinder 160 (not drawn) attached to the pivot bracket 162 on the grab frame and a second pivot bracket on the head plate 164 (not drawn), adjustable stops being provided if required.

The guide rod bushes or tubes 141 and 142 and the lift cylinder body 136, are attached to, and comprise part of, the head frame, generally indicted as 166 in Figures 1 and 2. This frame serves as a structural member to locate the guide rod tubes 141 and 142 relative to the pivot points 168 and 170.

The head frame is swung, from its front position over the middle station and over the layer station, to a position 166R over the load station by means of primary and secondary swing-over arm assemblies, generally 172 and 174 respectively. The primary swing-over arm assembly consists of a cross beam 176 and left and right hand double dog legged side beams 178 and 180 respectively, and is rotated about pivots 11 and 12 on the chassis from the front to rear positions shown in Figure 1 by "swing-over" cylinders (not drawn) or similar means. The secondary swing-over assembly consists of a cross beam 182 and left and right hand arms 184 and 186 respectively. By virtue or the geometry of these swing-over arms and their pivot points the head frame moves from 166 to 166R. During this motion the grab is held in its "up" position, and.

may be either straight or rotated 90% The layer of bales are thus carried over the load station. The grab 134 and its head plate are then lowered until either the lift lower cylinder reaches the end of its stoke (according to the first aspect of this invention this occurs for the first and second layer of the stack) or until the layer of bales comes into contact with layers of bales previously transferred to the load station. The hooks are then dis-engaged and the layer of bales released, the grab is raised and then swung back over to the middle station to await the signal that another layer has been formed in the layer station. In the case where a rotated layer has been placed in the load station the grab is rotated back straight when it reaches the middle station.

As mentioned above, the first or lower two layers of the stack are dropped rather than lowered all the way down by the cylinder 136, according to the first aspect of the invention. This method has the advantage that the cylinder 136 and its associated guide rods 138 and 140 need not be as tall as would be required for the first layer to be lowered all the way down to the base of the load station. As a result the overall height of the machine is not as great as it would otherwise have to be. Test have indicated that a stack so formed is not compromised by this indeed some advantage results, namely the first two layers of the stack are of a slightly open layout, allowing air circulation while the stack is standing in the field and thus improving the curing process that naturally occurs with hay and other crops.

The top three layers of the stack, however tend to retain the lateral tightness imparted by the push-over action.

The load station will now be described in greater detail, according to the first aspect of the invention. It is basically a box or container with one open side at the rear and with an open top. It is hinged at or near to its front lower corner. It is normally supported at a forward inclined angle to prevent any bales falling out of the rear from the complete or partly formed stack. It is lowered about its hinge or pivot points 9 and 10 until the rear lower corner touches the ground to enable the stack of bales to be discharged onto the ground.

Rollers 190,191,192, 193, 194 and 195 are mounted on bearings in the side members 196 (left hand) and 198 (right hand, not visible) and these rollers serve as supports for the first layer of bales of the stack. The left hand side or face of the load station consists of the side member 196, front post 200, rear post 202, a top side member 204, a side sheet or smooth inner surface which extends between the members 196, 200, 202 and 204 and such supporting and bracing members as are needed set between these members and on the outside of the side sheet. There is provided a similar right hand side or face member, also with a smooth or uninterupted inner surface, its rear post 212 and top side member 214 being visible on Figure 2.The front edge of the load station consists of upright members 220,221, 222 and 223 which serve to prevent bales in the load station from toppling forward and such cross members and diagonal bracing members as are needed to make the structure rigid. (not shown) The load station is also provided with cross members 224 and 226 between the side members 196 and 198 and with a cross member 228 between the top corners of the rear posts 204 and 214. The load station is raised and lowered by means of a pair of cylinders (not drawn) whose mounting pivot brackets are situated approximatly one third of the way up the front posts 200 and 210 (right hand, not visible) and on the front upper surfaces of the chassis rearward extensions 6 and 7.

According to the first aspect of this invention, the completed stack of bales, or a part completed stack if so desired, is unloaded at the operators discretion. The load chamber is lowered until the lower rear corner touches the ground and the stacker is then driven forward. A roller drive system rotates the rollers 190 to 195 in a clockwise direction (seen from the left hand side of the machine) and with a surface or periferal velocity equal to or slightly greater than the periferal velocity of the wheels 18 and 19. Relative to the ground, the stack being unloaded has no forward velocity or a slight rearward velocity. The drive system consists of a universally jointed drive shaft from the right hand land wheel 19 driving the input half of a clutch which is automatically engaged by a linkage to the load station when the load station is approximately halfway lowered.The output half of this clutch drives a chain sprocker, the chain of which drives a smallersproket.

This second sproket is connected to a gear wheel and both rotate freely on a stub shaft. The above mentioned gear wheel meshes with a smaller pinion gear wheel which is mounted on a shaft which is situated on the same centre line as the load station pivot point. This part of the roller drive system is located in the area between the chassis extension 7 and the land wheel 19. A chain and sprocket drive drive train takes the drive from the shaft and lies on the load station pivot line to each of the rollers 190 to 195. This final part of the drive is situated immediately outside the left hand lower side member 196. The left hand pivot mounting of the load chamber is situated to the outside of this, bridging members between this pivot mounting and the load chamber members 196 and 200 being provided such that they allow clearance for the roller drive chains and sprockets.

In an embodiment of the roller drive system, the drive is taken from the left hand land wheel. Alternatively the drive could be taken from both land wheels through a differential or by using over-run or sprag clutches.

Other embodiments of the discharge systems are as follows: land wheel (both or either) driven pumps driving a hydraulic motor attached to one of the rolles or operating a hydraulic cylinder that pushes the load out. Alternatively the motive power used to push the load out could originate from the main hydraulic system and the feed or push-out speed could be regulated by a land wheel driven metering valve. In the embodiment using one or a pair of push-off cylinders the front bale guides 220 to 223 could be mounted on a framework that could slide from its front position to the rear of the load station to push the load or stack of bales out of the load station. Alternatively both the front of the load station and the sides of the load station could be constructed as a single assembly that could slide backwards .relative to the floor of the load chamber.This sliding assembly, in either of the above mentioned forms could be driven backwards by push-off cylinder or cylinders. As an alternative to using a hydraulic flow rate proportional to the forward speed of the machine, it is proposed to use hydraulic oil flow from the main hydraulic system. In this case the stack would be propelled backwards out of the load station and tend to slide backwards over the ground until such time as the increasing frictional resistance between the ground and the parts of the stack bearing on the ground increased the total force required to move the stack relative to the load station to a point at which the hydraulic cylinder pressure reaches a relief or blow-off level.Once this pressure had been reached the push off cylinder or cylinders would move the stack out of the load station at a velocity equal and opposite to the forward velocity of the stacking machine. In this embodiment the "floor" of the load station could consist either of free running rollers or of a smooth tray or platform.

An embodiment of the push-off cylinder stack unloading system consists of a cylinder or pair of cylinders that serve the dual function of raising and lowering the load station and of pushing the completed stack out of the load station.

Reference will now be made, by way of example, to the power and control system employed in the prototype bale stacker. Motive power is provided by the tractor's hydraulic system and by a tractor mounted air compressor. Electrical power is provided by 24 volt batteries and a 24 volt alternator mounted on, and driven by, the baler. The push-over, push-over-lift and grab-rotate cylinders are pneumatic. The grab lift/lower, swing-over or layer transfer cylinders, the grab cylinder 152 and the load station lower/raise cylinders are hydraulic cylinders. The stack unload system derives its power from the right hand land wheel 19.Proximity switches provide the following "input" signals to the control system 11 - two bales nearly ready to be pushed over 12 - two bales ready to be pushed-over 13 - push bar either fully in or fully out 14 - push bar eitherfully up or fully down 15 - layer made (signal when layer made bar 34 is moved) 16 - grab lift cylinder 136 fully up 17 - swing over fully forward 18 - swing overfully back 19 - load station fully raised The following input signal are provided by manually operated switches: 110 - control system switch on (to automatic) 111 - emergency stop or safety switches not activated 112 - lower load station (activated when operator requires to discharge stack.

The automatic control system gives the following "output" signals: 01 - raise push-over bar (bar lowers with NOT signal) 02 - return push-over bar (bar pushes-over with NOTsignal) 03 - lower lift cylinder 136 04 - raise lift cylinder 136 (cylinder 'holds' in neutral valve position) 05 - engage grab hooks 06 - disengage grab hooks (cylinder 'holds' in neutral valve position) t7 - rotate swing-over arm 72 to rear (over load station) 08 - rotate swing-over arm to front (over layer station) (cylinder 'holds' in neutral valve position) 09 - raise load station 010 - rotate grab 90' 011 - de-rotate grab (i.e. back straight) (cylinder 'holds' in neutral valve position) 012 - sound horn (warning signal for operator) The control system consists, in the physical sense, of a electrical cabinet 230 in which is contained an electronic controller complete with input and output modules, fuse and terminal blocks and indicator lights, a pneumatic control cabinet 232 in which is contained pilot solenoid valves and the pneumatic cylinder control valves, a hydraulic control valve area 234 in which is situated air operated hydraulic control valves, a static inverter 236 which provides the stable electrical supply required by the particular electronic controller and solenoids used, a battery cabinet 238, a remote switch unit (not drawn) with such switches and indicator lights as the operator/tractor driver needs adjacent to his driving position.In embodiments of the control and power system, different power or control media could be used. It could be practical for the automatic control to be carried out by fluid logic, alternatively the control system could operate on 12 volt direct current eliminating the requirement for the static inverter.

The functions of the controller are as follows: To cycle the push-over. When signal or input 11 is received, to cycle the push-over bar from P2 to P3 to P4 to P1 with an inhibit delaying this if the grab is in the front position and lowered. When 12 is received, to cycle push over from P1 to P2 (to push over two bales).

To cycle the layer transfer. At signal "layer made",15, to lower grab from cycle start position (swing forward, grab up, rotated straight, claws or hooks "out" or diengaged), after time delay to engage hooks, after time delay to raise grab, examine memory to determine if layer has to be rotated, rotate grab 90 if required, swing grab to back position (with motion inhibit if load station not in raised position), lower grab, after time delay disengage hooks (to release layer), after time delay raise grab, examine memory - sound horn one blast if five layers have been stacked (i.e., signal full stack can now be unloaded), at same time swing to front position, de-rotate grab if not straight, await next 15 signal.If memory states full stack has not been lowered when next layer has been raised to the front swing-over position, this layer (which is the first layer of the next stack) is held until the load chamber has been lowered and raised again after unloading the stack. In addition to holding the above mentioned layer, the control system is programmed to sound the horn with three blasts. Should the operator not have lowered the load chamber and unloaded the stack when a further layer has been completed in the layer station, the horn will be sounded continuously until the operator unloads. Upon the load station returning to the up position the swing-over to start the next stack will commence. It can happen that the operator lowers and unloads a part height stack at a time when the next layer is part rotated in the 'middle' station, or is being swung over to the back.In such cases the controller is programmed to swing the layer to the forward position (if required) and to de-rotate the layer as the first layer of a stack should be straight.

If the operator throws the "automatic on/off" switch to "off" during the cycle the controller will hold the cycle at the end of the stroke until the switch is thrown back to "on". The cycle will then continue. (This facillity is intended to allow the operator to remove a broken bale, for example). When the automaic switch is at "off" the operator can over-ride any valve but must return any mechanism to the position at which the automatic cycle was stopped. If not the controller will sound the horn continuously when the automatic switch is returned to "on" (to indicate a "fault" situation) and will not allow the cycle to proceed. If the operator then switches to "off", puts the offending mechanism to its correct position and switches to automatic "on" the cycle will continue.

In addition the controller scans all input signals at each time base (one hundreth of a second) and if an "out of normal" combination of inputs exists it is programmed to either "top-up" any motion that is likely to creep from end to stroke due to seal leakage (i.e. the grab may creep down or the load chamber may creep down (to "top-up" is to signal the appropriate valve to raise the offending mechanism to its end of stroke position) or, in the case of any other "out of normal" signal, the controller blows the horn (to signal "fault") and stops the cycle. The input and output indicator lights indicate the signals being given and are thus of assistance to the operator when he wishes to find out why a "fault" has been signalled. (For example, a proximity switch may have been forced out of position or a electrical wiring fault may have occured).

If the power is switched "off" the controller's memory of the cycle state is lost. In such cases the operator must manually cycle any movements to the cycle start position and then the controller will, when switched to "automatic on" be ready to start a cycle with a clean memory.

The control programme described above can be entered either on a "soft" (magnetic) programme or on a permanent "etched" programme. In the case of the former, programme changes can be made with a programme entry unit or terminal. For example, a time delay could be reduced or extended. In the case of a permanent programme, a new programme would have to be entered on to a different programme memory element and the programme entry element would have to be changed or swapped by the physical removal of the one and the replacement of the new programme element. The removed programme could, of course, be retained for re-installation at a later date if required. It can thus be seen that the control system can be reprogrammed to allow the control parameters listed above to be re-specified.In the embodiment according to the fourth aspect of this invention, a stacking and unstacking machine could be provided with a double programme for its alternate uses. The control function can be extended to handle more input or output signals if required.

The bale stacker as illustrated in Figures 11 and 12 will now be described in some detail to demonstrate various aspects, by way of example, of embodiments of the bale stacker according to the first aspect of this invention. Refering to Figure 11 it will be seen that the push-over and layer forming tray are inclined at the same angle as the load station to reduce the height the layers have to be raised, to allow the overall length of the stacker to be reduced and its wheel base (from hitch point to axle line) to be reduced, to allow a layer transfer from above the layer station to above the load station to be achieved by a motion or mechanism that does alter the angle or the inclination of the layer, to allow space under the push-over and layer forming tray for such embodiments as the "under-mounted" push-over shown schematically in Figure 10 or the load push-off cylinder or cylinders as described earlier.

The clamp 240 is generally as that in Figure 8 except that it is provided with bearing housing 242 that is attached to the grab frame by means of spring loaded bolts 244 to allow the grab frame to "rock" on the bearing housing should an uneven layer or obstruction occur and except that a different rotate cylinder pivot bracket 246 is provided attached to the bearing housing 242. The layer transfer system is however different and consists of a swinging arm 248 that pivots on a carriage assembly, generally indicated as 250, which carnage moves up and down the mast channels 252 and 254 in the manner that a fork lift trucks carriage plate travels up and down its mast.

In the following description the various members of the carriage, mast and swinging arm will be described as vertical or horizontal, etc. as if the transfer mechanism as a whole were mounted vertically and not inclined forwards at an angle of approximately 10% The carriage 250 consists of an upper 'horizontal' plate 256 and a lower horizontal plate 258 attached to a vertical plate 260 with vertical webbs 262 and 264. The carriage is provided with eight guide rollers 270 to 277 which locate the carriage assembly in the mast channels 252 and 254 and allow its movement up and down these mast channels. A lift and lower cylinder (not drawn) is located between the mast channels and powers the carriage up and down the mast channels hereafter refered to as the mast.The mast is suitably braced and attached to the chassis The swinging arm 248 pivots horizontally about pivot bearings attached to, or mounted on, the horizontal carriage plates 256 and 258 and its motion from its forward position (as drawn) to its rear position (drawn dash dash) is achieved by means of a swing cylinder 260 mounted in pivot brackets on the carriage plates 256 and 258 and pivot brackets 262 attached to the swinging arm. The grab can rotate relative to the swinging arm and this rotation is controlled by a cylinder 264 with an extended rod 266.This rotate cylinder is mounted at pivots 246 on grab bearing housing 242 and pivots 268 on the carriage plates 256 and 258, the geometry of these pivots being such that the grab is positioned "straight" over the load chamber when rotate cylinder 264 is extended and is positioned "rotated 90 " over the load chamber and is positioned "straight" over the layer station when the rotate cylinder 264 is retracted.

To enable the carriage and swinging arm to lower to the formed layer in the layer-tray and to lower to place the first layer in the load chamber or station, the pushover support member 270 is "dog-legged" and attached to the mast at its rear end and the front left hand corner of the load station sides are 'cut-away' or left open.

CLAIMS (filed on 17.4.81) 1. A stack-forming machine for serially receiving rectangularly shaped bales or other objects (hereinafter referred to as "bales") having in plan view a longitudinal dimension (the length) differing substantially from the transverse dimension (the width) or an exact multiple thereof and for forming said bales into multi-layer stacks thereof, wherein when the machine is in operation receiving bales (a) said bales are transferred from a receiving station to and arranged side by side and end to end in a layer-forming station to form there a single layer of said bales comprising an array of at least two by two such bales; and - (b) each such layer is transferred in turn from said layer-forming station to a stack-forming station and deposited there to constitute one layer of a stack beng formed there, selected or alternate such layers (i) being rotated during the course of such transfer to said stack-forming station through an angle of ninety degrees so that in selected pairs of alternate layers of the stack being formed the longitudinal directions of the bales lie at right angles to one another, and (ii) being positioned so that in each or selected layers, junctions of adjacent bales are offset from those in the adjacent layers.

2. A machine according to Claim 1, including (2) means constituting said receiving station; (b) means constituting said layer-forming station; (c) bale transfer means for effecting transfer of said bales from said receiving station to said layer-forming station; '(d) means constituting said stack-forming station; (e) layer transfer means for effecting transfer of said layers from said layer-forming station to said stack-forming station, and including rotation effecting means for effecting rotation as aforesaid of said selected or alternate layers, the transfer means being arranged to achieve said offset of said junctions; and (f) sequence control means effective when in operation to control said bale transfer means, said layer transfer means and said rotation effecting means in a manner such that bales receive serially at said bale receiving station are assembled into successive layers at said layer-forming station, and such that such layers arethen assembled into stacks at said stack-forming station.

3. A machine according to Claim 2, wherein said receiving station means includes a track for receiving bales travelling in their lengthwise direction, and said layer-forming station includes a table disposed alongside said track, and said bale transfer means includes means for displacing bales on said track in a direction transverse to said direction whereby to assemble bales into a said layer on said table.

4. A machine according to Claim 3, wherein said bale transfer means is arranged and is controllable so as to simultaneously displace in said transverse direction at least two bales standing end to end on said track, whereby to transfer such plurality of bales as a bale set on to said table of said layer-forming station.

5. A machine according to Claim 4, wherein said bale transfer means includes a bale propelling or pushing member and an associated actuating means, said pushing member being supported and positioned

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (36)

**WARNING** start of CLMS field may overlap end of DESC **. bearing housing should an uneven layer or obstruction occur and except that a different rotate cylinder pivot bracket 246 is provided attached to the bearing housing 242. The layer transfer system is however different and consists of a swinging arm 248 that pivots on a carriage assembly, generally indicated as 250, which carnage moves up and down the mast channels 252 and 254 in the manner that a fork lift trucks carriage plate travels up and down its mast. In the following description the various members of the carriage, mast and swinging arm will be described as vertical or horizontal, etc. as if the transfer mechanism as a whole were mounted vertically and not inclined forwards at an angle of approximately 10% The carriage 250 consists of an upper 'horizontal' plate 256 and a lower horizontal plate 258 attached to a vertical plate 260 with vertical webbs 262 and 264. The carriage is provided with eight guide rollers 270 to 277 which locate the carriage assembly in the mast channels 252 and 254 and allow its movement up and down these mast channels. A lift and lower cylinder (not drawn) is located between the mast channels and powers the carriage up and down the mast channels hereafter refered to as the mast.The mast is suitably braced and attached to the chassis The swinging arm 248 pivots horizontally about pivot bearings attached to, or mounted on, the horizontal carriage plates 256 and 258 and its motion from its forward position (as drawn) to its rear position (drawn dash dash) is achieved by means of a swing cylinder 260 mounted in pivot brackets on the carriage plates 256 and 258 and pivot brackets 262 attached to the swinging arm. The grab can rotate relative to the swinging arm and this rotation is controlled by a cylinder 264 with an extended rod 266.This rotate cylinder is mounted at pivots 246 on grab bearing housing 242 and pivots 268 on the carriage plates 256 and 258, the geometry of these pivots being such that the grab is positioned "straight" over the load chamber when rotate cylinder 264 is extended and is positioned "rotated 90 " over the load chamber and is positioned "straight" over the layer station when the rotate cylinder 264 is retracted. To enable the carriage and swinging arm to lower to the formed layer in the layer-tray and to lower to place the first layer in the load chamber or station, the pushover support member 270 is "dog-legged" and attached to the mast at its rear end and the front left hand corner of the load station sides are 'cut-away' or left open. CLAIMS (filed on 17.4.81)

1. A stack-forming machine for serially receiving rectangularly shaped bales or other objects (hereinafter referred to as "bales") having in plan view a longitudinal dimension (the length) differing substantially from the transverse dimension (the width) or an exact multiple thereof and for forming said bales into multi-layer stacks thereof, wherein when the machine is in operation receiving bales (a) said bales are transferred from a receiving station to and arranged side by side and end to end in a layer-forming station to form there a single layer of said bales comprising an array of at least two by two such bales; and - (b) each such layer is transferred in turn from said layer-forming station to a stack-forming station and deposited there to constitute one layer of a stack beng formed there, selected or alternate such layers (i) being rotated during the course of such transfer to said stack-forming station through an angle of ninety degrees so that in selected pairs of alternate layers of the stack being formed the longitudinal directions of the bales lie at right angles to one another, and (ii) being positioned so that in each or selected layers, junctions of adjacent bales are offset from those in the adjacent layers.

2. A machine according to Claim 1, including (2) means constituting said receiving station; (b) means constituting said layer-forming station; (c) bale transfer means for effecting transfer of said bales from said receiving station to said layer-forming station; '(d) means constituting said stack-forming station; (e) layer transfer means for effecting transfer of said layers from said layer-forming station to said stack-forming station, and including rotation effecting means for effecting rotation as aforesaid of said selected or alternate layers, the transfer means being arranged to achieve said offset of said junctions; and (f) sequence control means effective when in operation to control said bale transfer means, said layer transfer means and said rotation effecting means in a manner such that bales receive serially at said bale receiving station are assembled into successive layers at said layer-forming station, and such that such layers arethen assembled into stacks at said stack-forming station.

3. A machine according to Claim 2, wherein said receiving station means includes a track for receiving bales travelling in their lengthwise direction, and said layer-forming station includes a table disposed alongside said track, and said bale transfer means includes means for displacing bales on said track in a direction transverse to said direction whereby to assemble bales into a said layer on said table.

4. A machine according to Claim 3, wherein said bale transfer means is arranged and is controllable so as to simultaneously displace in said transverse direction at least two bales standing end to end on said track, whereby to transfer such plurality of bales as a bale set on to said table of said layer-forming station.

5. A machine according to Claim 4, wherein said bale transfer means includes a bale propelling or pushing member and an associated actuating means, said pushing member being supported and positioned so as when actuated by said associated actuating means to push the aligned bales constituting a bale set in said transverse direction from said receiving station track on to said layer-forming station table, and retracting means for temporarily retracting said bale pushing member during its withdrawal to a starting position, so as to avoid during such withdrawal interference with any next bale set (or with a part thereof) then standing on said receiving station track.

6. A machine according to Claim 4 or Claim 5, including firstly auxiliary control means for supplying to said sequence control means a signal indicative that a predetermined number of bales constituting a bale set are standing in position on said receiving station track ready for transfer to said layer-forming station table, said sequence control means being responsive to such a signal to initiate operation of said bale transfer means.

7. A machine according to Claim 6, including second auxiliary control means for suppying to said sequence control means a signal indicative that a predetermined number of bale sets constituting a layer of bales are aligned lengthwise side by side on the said table, said sequence control means being responsive to such a control signal to initiate operation of said layer transfer means.

8. A machine according to any one of the Claims 2 to 7, wherein said layer transfer means includes a layer-grabbing means (hereafter referred to as the grab) comprising means for physically engaging with and gripping a said layer of bales standing at said layer-forming station, and an associated grab actuating means for causing said grap to grip and subsequently release a said layer of bales, and a grab translating means carrying said grab and having an associated actuating means for causing translation of said grab from a position over a layer of bales standing at said layer-forming station to a position over said stack-forming station, said rotation effecting means being associated with said grab and said grab translating means and being operable to achieve relative rotation of said grab and grab translating means.

9. A machine according to Claim 8, wherein said layer transfer means also includes a grab lowering/lifting means interposed between said grab and said grab translating means, and operable when said grab is positioned above said layer-forming station or said stack-forming station to move said grab towards and subsequently away from such a station so as to effect the raising of a layer of bales from the layer-forming station and the subsequent lowering of such a layer of bales at said stack-forming station.

10. A machine according to Claim 8 or Claim 9, wherein said grab translating means comprises a frame for supporting directly or indirectly said grab, which frame is pivotally carried on at least one supporting side link which is itself pivotable about a fixed axis disposed parallel to a layer-forming table constituting said layer-forming station for the purpose of effecting translation of said grab from and to a position above said layer-forming station.

11. A machine according to Claim 10, wherein said frame is also pivotally carried on at least one auxiliary side link, which is pivotable about an axis parallel with but displaced from said fixed axis of said supporting side link, and which auxiliary side link controls the attitude of said frame and grab during translation thereof.

12. A machine according to Claim 11, wherein said stack-forming station includes a stack-forming table which is inclined at a small angle to the plane of a layer-forming table constituting said layer-forming station, and wherein said auxiliary side link is different in length from said supporting side link whereby said frame is translatable between a position above and parallel to said layer-forming table to a position above and parallel to said stack-forming table.

13. A machine according to Claim 8, wherein said stack-forming station includes a stack-forming table which is parallel with a layer-forming table constituting said layer-forming station, and wherein said grab translating means comprises an arm pivoted for angular motion about an axis normal to said layer-forming and stack-forming tables, an associated actuating means for causing angular motion of said arm about said axis, and lifting/lowering means for displacing said arm relative to said tables along said axis whereby to enable said grab to be moved towards and away from the said table at the relevant station.

14. A machine according to Claim 13, wherein said grab translating means also includes a parallel motion link pivoted at one end of said grab, and at the other end about an axis parallel to but displaced from' said axis normal to said tables, whereby during angular displacement of said grab by said associated actuating means the alignment of said grab relative to said tables is maintained constant, and wherein said rotation effecting means comprises means for adjusting the effective length of said parallel motion link.

15. A machine according to Claim 14, wherein said means for adjusting the effective length of said parallel-motion link comprises a cylinder and piston arrangement, and fluid control means for adjusting the relative positions of said cylinder and piston.

16. A machine according to any one of the Claims 2 to 15, including third auxiliary control means responsive to the completion of a stack being formed at said stack-forming station, for giving warning to said sequence control means or to a machine operator of the completion of a stack.

17. A machine according to any one of the Claims 2 to 16, including stack expulsion means for effecting expulsion of a newly formed stack from said stack-forming position, said stack expulsion means being controllable automatically by said sequence control means, or by a machine operator.

18. A machine according to Claim 17, wherein a table at said stack-forming station for receiving and carrying said layers of bales during the formation of a stack is pivotally mounted at one end thereof and provided with actuating means for lowering the opposite end thereof whereby to enable a newly formed stack to slide off or otherwise be expelled from that table.

19. A machine according to Claim 18, wherein said stack expulsion means includes means for urging a newly formed stack in the direction of said opposite end of said table after the lowering of that end by said actuating means.

20. A machine according to Claim 18 or Claim 19, wherein said table at said stack-forming station includes a set of parallel rollers for enabling a newly formed stack standing thereon to roll or be rolled from said stack-forming station upon the lowering of said opposite end of the table.

21. A machine according to Claim 20, wherein said stack expulsion means includes means for driving said rollers whereby to rotate said rollers and thereby expel said newly formed stack standing on said rollers.

22. A machine according to any one of Claims 2 to 21, including a base frame on which at least said means constituting said layer-forming and stack-forming stations are carried, said base frame being mounted on road wheels whereby said machine may be readily moved over the ground to deposit newly formed stacks at different locations.

23. A machine according to Claim 22 as dependent on any one of the Claims 18 to 21, wherein said machine is arranged for being towed or driven over the ground on said road wheels, and said stack-forming station is disposed for depositing each newly formed stack on the ground to the rear of the machine as the latter is moving forwardly over the ground, said stack-forming table being pivotally mounted at its forward (i.e. in the direction of travel of the machine) end, and at least the opposite, rear end of said table being capable of being lowered by the associated actuating means below said forward, pivoted end whereby to enable a newly formed stack standing on said table to roll or be rolled from that table on to the ground.

24. A machine according to Claim 21, or to Claim 22 or Claim 23 a dependent on Claim 21, wherein said rollers of said stack-forming table are driven from at least one of said road wheels.

25. A machine according to any one of the Claims 22 to 24, wherein each said newly formed stack is expelled from said stack-forming table at a velocity substantially equal to and opposite the forward velocity of the machine over the ground, so that the velocity of each such stack relative to the ground on meeting the ground is of zero or low value.

26. A machine according to any one of the Claims 22 to 25, wherein said layer-forming station is disposed in line in the intended direction of travel of the machine over the ground and forward of said stack-forming station, so that said layer transfer means transfers each said layer of bales in a rearward direction to said stack-forming station.

27. A machine according to Claim 26, wherein said receiving station is disposed alongside said layer-forming station, and said bale transfer means is arranged to move bales standing at said receiving station to said layer-forming station in a direction transverse to the intended direction of travel of the machine over the ground.

28. A machine according to Claim 27, wherein said receiving station is arranged to receive bales moving in the rearward direction from a source disposed forwardly of said receiving station.

29. A machine according to any one of the Claims 22 to 28, wherein said road wheels comprise wheels mounted for rotation about a single axis which is so positioned in relation to said layer-forming and stack-forming stations that in operation when the machine is being towed along coupled to a towing hitch at the rear end of a baling machine, an upward thrust exerted by the stack-forming machine on the towing hitch of the baling machine increases progressively as successive layers of bales are placed on the stack-forming station.

30. A machine according to any one of the Claims 22 to 29, wherein said road wheels comprise wheels mounted for rotation about a single axis, wherein the machine is provided with a towing hitch for coupling with a complementary towing hitch at the rear end of a predetermined baling machine, and wherein said towing hitch of said stack-forming machine is positioned relative to said wheels and said receiving, layer-forming, and stack-forming stations thereof such that when said stack-forming machine is being towed by said baling machine the stack-forming machine trails within the path bounded by the spaced, parallel loci of the transverse extremities of the baling machine.

31. A machine according to any one of the Claims 2 to 30, wherein said layer transfer means and said sequence control means are arranged so that transfer of a layer of bales to said stack-forming station after being removed from said layer-forming station may be temporarily interrupted so as to enable the expulsion of a newly formed stack to be delayed temporarily whilst still allowing a next layer of bales to be formed at said layer-forming station, whereby to enable expulsion of a stack to be effected at a convenient time or place and without unnecessarily interrupting the layer-forming process.

32. A machine according to Claim 17, wherein a table at said stack-forming station for receiving and carrying said layers of bales during the formation of a stack is provided with actuating means for lowering to ground level at least the edge of said stack-forming table remote from said layer-forming station, whereby to enable a newly formed stack to slide off or otherwise be expelled from that table onto the ground without causing any substantial change in the upright attitude of the stack.

33. A machine according to any one of the Claims 2 to 32, wherein said layer transfer means is arranged to transfer each said layer of bales from said layer-forming station to said stack-forming station via a bale treatment station at which said bales are provided with a predetermined bale treatment.

34. A machine according to any preceding claim, wherein the sequence of operation can be reversed at will so as to receive stacks at said stack-forming station, to transfer the successive layers of a stack to said layer-forming station, and to transfer the successive bales of a layer to said receiving station for delivery and use elsewhere.

35. A machine according to any preceding claim, substantially as hereinbefore described with reference to and as illustrated by Figures 1 and 2 taken in conjunction with any of the Figures 3 to 10.

36. A machine according to any one of the Claims 1 to 34, substantially as hereinbefore described with reference to and as illustrated by Figures 11 and 12 taken in conjunction with any relevant one or group of the earlier figures.