AU2010202808A1 - Bale stack machine - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED "BALE STACK MACHINE" This invention is described in the following statement:- -2 BALE STACK MACHINE Field of the Invention 5 The present invention relates to a towable bale stacker, for stacking one large fodder bale on top of another. Background of the Invention 10 Balers are bale making machinery and can produce fodder bales of hay, straw or other fodder. The baler is used to compress and bind a cut crop of, for example, hay, straw or chaff into fodder bales. Square or rectangular bales can be stacked and can be easier to transport than round bales, thus square and rectangular balers can be preferred by farmers who produce export quality hay. Also such bales tend to 15 weather better than round bales. The bales would be produced by the baler and delivered to the field for subsequent collection and storage. Some dedicated large balers incorporate automatic stacking and unloading devices. Such machines tend to be very expensive and are typically not used on small to 20 medium sized farms. More commonly the baler is towed behind a farm tractor. With the increased availability of higher horse power tractors, it was possible to also tow a bale accumulator behind the baler. The accumulator would collect a number of the 25 smaller rectangular bales before delivering the collected bales in a packed group in the field. This arrangement had the advantage of reducing the number of collections and trips required to store all of the produced bales. The bale accumulators also known as bale sledges can deliver eight small rectangular bales together in a group and some accumulators also stack and re-orientate the bales using hydraulic or 30 electrical power from the tractor. 02/07/10jbI8090 cap specification.doc,2 -3 Older balers produced small rectangular bales, which may weigh 20 to 25 kg, which could be managed by hand. More modem balers, and particularly those used for the production of export bales tend to produce what are known as large bales. Large bales can include square and round bales, the former being preferred for ease of 5 transport as round bales can require specialized equipment for safe transport. The square bales are square in cross section but are rectangular in shape. Typically a square bale is 3 x 3 x 6 feet or 4 x 4 x 8 feet and may weigh in the order of 500 to 1000 kg. One square bale may contain 20 - 40 small bales. The use of large bales 10 significantly reduces the number of trips required to collect and store the same mass of fodder but require front end loaders or bale grabber attachments on a tractor. The bale accumulators intended for use with small bales is not suitable for the large square bales. 15 There are benefits in producing twin stacks of square bales. The farmer can save time and money by reducing the number of collections by half. High water content can reduce the value of the bales so that it can be useful to quickly collect and store the bales. 20 The following US patents describe various bale stacking systems, US Patent No. 3,308,971 (Sinden); 2,971,318 (Solem), 3,302,807 (Blair), US 3,443,708 (Blair) and 5,046,918 (Berlivet). It is not known if any of the systems described in these patents has ever been commercially produced. The older systems are directed to small bales, as square balers are a relatively recent development. 25 US 3,308,971 (Sinden) describes a towed hydraulically powered bale stacking device, whereby a delivery chute is hydraulically moved to provide 8 small bales in two layers of four bales. The arranged bales are held within the towed cage and discharged when the restraining arms (69) at the rear of the cage are opened. It uses a 30 complicated mechanical system to control the operation of the arms. 02/07/10,jb18090 cap specification.doc,3 -4 US 2,971,318 (Solem) describes a towed bale stacking device for providing 4 small bales in two layers of two bales. It appears to be a mechanically complex system and uses a mechanical gate (31, 32) to control the discharge of the bales. 5 US 3,302,807 (Blair) describes a towed bale stacking device for providing 4 small bales in two layers of two bales. The first and second bales fall into the body of the sled and the third and fourth bales passes on top. When properly positioned the end of third bale contacts a lever with unlocks a rear gate and thereby discharges the stacked bales. 10 US 3,443,708 (Blair) describes a towed bale accumulator for special field conditions. It is a mechanically actuated bale accumulator of four bales in two layers of two bales. It includes a guide rod (34) which directs the bales downward. A rear gate controls the release of the accumulated bales. It uses chains as hitch links to the 15 accumulator as well as guides for the bale. US 5,046,918 (Berlivet) appears to describe a towed bale stacking device for stacking two medium sized bales. It uses a mechanically complicated arrangement using retractable and tiltable slides for supporting the bales and controlling their 20 discharge. It omits a rear gate and instead uses a perfectly synchronized tilting movement of the slides to discharge the bales. It also omits to describe how the operation of the rear control lever achieves a two step function. It would be advantageous to provide a mechanically simple twin bale accumulator 25 and stacker for small to medium sized farming operations. The stacker should avoid using power including hydraulic systems and reduce mechanical complexity so to simplify maintenance and repairs. The bale retention and release system should be simple. 30 It would be advantageous if the stacker was largely automated and functionally easy to use in common conditions. As large bales can be long and the stacker is towed behind the baler, it is important that any towed stacker is capable of retaining the 02107/Ojb l8090 cap specification.doc,4 -5 bale whilst it is extruded from the baler over a range of field conditions including turning the baler. It would be advantageous to provide a big bale stacker capable of stacking both hay 5 and straw bales. Hay is made from grasses and legumes and is denser and contains more nutrients than straw. Straw bales are lighter than hay bales, do not fall from the baler in the same way as hay bales and may bounce around and off the stacker as the towed stacker bounces around on the uneven or rough surface of paddocks. 10 Summary of the Invention A bale stacker for square or rectangular hay or straw bales comprising: a) a longitudinally elongated frame having a bale receiving front end and a rear end and two sides; 15 b) a hitch at the frame front end for attachment to a rear delivery baler; c) a pivoting bale support platform for supporting bales received by the bale stacker, the platform pivotally connected to the frame about an axis substantially perpendicular to the longitudinal axis of the frame, the axis located forward of the centre of gravity of the unloaded support platform, the platform having a front 20 section toward the front end of the frame and forward of the pivot axis, and a rear section toward the rear end of the frame and rearward of the pivot axis; d) a spring connected to the frame and platform, the spring capable of raising the rear section and lowering the front section of an unloaded support platform about the pivot axis but not capable of doing the same when the support platform carries a bale 25 stacked above another bale; e) a releasable platform restraint connected to the frame and capable of engaging the platform when the rear section of the support platform is raised and, when engaged, the restraint prevents the downward pivoting motion of the raised rear section of the support platform until the restraint is disengaged; 30 f) a stacked bale sensor capable of sensing an end of a stacked bale when the stacked bale end is at or near the rear end of the elongate frame; 02/07/10jb 18090 cap specification.doc,5 -6 g) the stacked bale sensor being operationally associated with the releasable restraint, whereby the restraint is disengaged after the sensor senses a stacked bale end at a desired position in the bale stacker; and h) side bale restraint members at the sides of the frame capable of limiting sidewise 5 movement of received bales. Preferably the frame of the bale stacker has one or more upwardly extending bale engaging spike(s), which upwardly protrude through the front section of the support platform when the front section of the support platform is lowered and do not 10 protrude through the support platform when the front section of the support platform is raised. Preferably the bale stacker includes an upper bale restraint for directing bales received from the baler toward the support platform and restraining received bales 15 from excessive up movement. The above bale stacker avoids complicated mechanical loading systems and does not require powered or hydraulic connectors to operate. The simple mechanical operation automates bale stacking whilst reducing the cost of production and provides ease of 20 maintenance for the end user. It can be used with large square bales to produce twin stacks of bales. The upper bale restraint permits the use of the bale stacker over excessively rough ground and with hay or straw bales. In operation, the bale stacker is hitched to and towed behind a baler. When the bale 25 stacker is in the unloaded state, the spring returns the rear section of the unloaded support platform to a raised position and the platform restraint engages the platform and holds it in position. The first bale from the baler is pushed into the front of the baler stacker towards the 30 rear. The unsupported front portion of the first bale travels in a rearward and downward direction until it contacts the support platform and then continues to move rearward but also upward along the inclined surface of the support platform. The first 02/07/10jbl8090 cap spccification.doc,6 -7 bale is pushed further into the bale stacker by the second bale from the baler and eventually wholly falls onto and is supported by the support platform. When the rear end of the first bale falls onto the support platform it contacts and is speared onto the bale spikes extending through the support platform. These spikes prevent further 5 movement of the first bale. Preferably the pivoting support platform includes a substantially flat support surface fastened to a pivoting frame. The support surface may be formed from any durable sheeting material including metal sheeting or plywood. The support surface may 10 include a higher slip cover such as a polymer sheet, e.g. a nylon cover, to make it easier to slide the bale along the support surface. Once the first bale falls into the bale stacker, the front end of the second bale is above the upper surface of the first bale. The second bale is pushed along the upper 15 surface of the first bale by the next bale from the baler. Eventually the front end of the second bale is located substantially above the front end of the first bale. When the end of second bale appropriately located the sensor triggers the release the platform restraint. As the pivot axis is forward of the centre of gravity and the weight of the loaded bales overcomes the force of the springs, the rear section of the platform 20 moves downward and the front section moves upward. When the front section moves upward it lifts the bale off the bale spikes which permits the stacked bales to slide off the platform onto the field. Once the stacked bales leave the rear of the stacker, the unloaded support platform is 25 returned to its normal position by the springs ready to start the stacking process again. Preferably the spring is connected to the rear section of the support platform. Springs are preferred but could be replaced with an alternative means for returning the rear 30 section of an unloaded platform to a raised position. An alternative is a dead weight and pulley system. 02/07/10jbI8090 cap specification.doc,7 -8 Although more sophisticated sensors for the end of the stacked bale may be used, it is preferred to use a mechanical device in the form of a rotating lever arm with a spring return. The arm is positioned in the path of the stacked bale and is rotated as the end of the stacked bale travels rearward. Such a sensor can be operationally 5 associated with the platform restraint by chain links or rope such that the rotational motion of the arm changes the tension on chain or rope and thereby disengages the platform restraint. Preferably the platform restraint is a spring loaded bar and is positioned such that 10 spring forced extension of the bar is possible when the rear section of the platform is raised. The bar may fit into an aperture in the platform when it is in that position. Alternatively the bar may extend above an upper surface of the lowered front section of the platform or below a lower surface of the raised rear section of the platform. The restraint can be released by withdrawing the extension of the bar by applying 15 sufficient force to overcome the spring. Preferably the sensor assembly which includes the rotating lever arm with a spring return is mounted at an upper rearward side portion of the frame. It can be simply welded or bolted to the frame for use with bales of a standardised size. More 20 preferably, the sensor assembly can be adjustability positioned to all for greater control over when the sensor releases the platform restraint. Preferably the mounted on a shaft affixed to the frame, it may be clamped to the shaft or coupled to a threaded shaft and locked in place with locking nuts on either of the assembly. 25 The bale stacker should be towed behind a rear delivery baler. This normally requires the fitting of baler hitch attachment and a bale ramp to the rear of the baler. Preferably the hitch includes at least one pair of uncrossed chains which connect the front of the stacker with the rear of the baler. The hitch may also include a central 30 hitch. It can be advantageous to have a long draw bar to the hitch. The long draw bar positions the bale support platform further away from the rear of the baler. This enables the use of a long bale ramp and requires a reduced ramp angle to the 02/07/10jbl8090 cap specification.doc,8 -9 horizontal to readily deliver the upper bale on to the lower bale as compared to a short ramp arrangement. A reduced angle places less work on the baler and the upper bale is less likely to be caught up on the leading upper front edge of the lower bale. 5 It is preferred to include bale guide members on the frame of the bale stacker. These guides act to prevent or manage the excessive movement of bales on the bale stacker. It is advantageous to include guide members at the forward sides of the bale stacker near the bale ramp to control the sideways movement of bales leaving the ramp. Also it is advantageous to include a top guide member bridging across the sides of the 10 frame to control upward movement of bales being loaded onto the bale stacker. It can be advantageous to include a bale stopper at or near the rear of the support platform to reduce or prevent a lower bale from sliding out of the bale stacker when going up a hill. Preferably the bale stopper is a simple mechanical system operates 15 when the rear section of the support platform is raised and disengages when the rear section of the support platform is lowered. In a preferred form the bale stopper is an upwardly extending and pivoting member located on an extension shaft, the shaft extending from the rear end of the bale support platform, the member capable of pivoting over centre out of the way of the bale when the support platform is lowered 20 and the bales slide off the bale support platform. Brief Description of the Figures Figure 1 is a side view of an unloaded bale stacker of the present invention behind a 25 tractor towed baler. Figure 2 shows the arrangement of figure 1 with bales loaded on the bale stacker. Figure 3 is a side view of the bale stacker of figure 1 and the rear of the baler, the 30 bale ramp assembly and the baler hitch attachment. 02/07110,jbI8090 cap specification.doc,9 -10 Figures 4 to 9 are side sectional views depicting consecutive stages in the operation of a bale stacker of the invention. The depicted bale stacker is a short ramp and short draw bar variant of the bale stacker of figure 3. 5 Figures 10 and 11 are respectively above and below perspective views of the bale stacker of figure 3. Figure 12 is a plan view of the bale stacker of figure 3 together with a portion of the bale ramp assembly. 10 Figure 13 is a side, section view of the bale ramp assembly and the bale stacker of figure 3. Figure 14 is a cut away above perspective view of the support platform of the bale 15 stacker of figure 3. Figures 15 and 16 are cut away perspective views of a wheel assembly of the bale stacker of the present invention. 20 Figures 17 and 18 are perspective views of the bale sensor assembly of the bale stacker of the present invention. Figure 19 is an exploded perspective view showing the baler attachment for hitching the bale stacker of the invention to the baler, the bale ramp and the front of a baler 25 stacker of the present invention. Figures 20 to 23 are respectively side, plan, and for figures 22 to 23, perspective views of the bale stopper of the baler stacker of the invention, in the blocking configuration. 30 Figure 24 is a perspective view of the bale stopper of figures 20 to 23, in the release configuration. 02/07/]Ojb 18090 cap specification.doc,10 Figures 25 to 29 are cut away side views showing the consecutive steps in the operation of the bale stopper of the bale stacker of the invention. While the invention will be described in connection with the preferred embodiment 5 below, it will be understood that it is not intended to limit this invention to this embodiment or the details of construction or arrangement illustration in the accompanying drawings. As shown in figures 1 and 2 the bale stacker (1) of the present invention is towed 10 behind a large square baler (3) which in turn is towed by the tractor (4). The direction of motion of tractor is shown by arrow (5). Typically the tractor and thus the bale stacker moves up to 20 km per hour. The baler (3) is fitted with a bale ramp assembly (7) and baler hitch attachment (9) 15 having appropriate fittings for fitting the attachment to the baler. The baler hitch attachment has a standard hitch coupling including a towbar. The towbar can be fitted with a ball for use with a complimentary socket connector on the bale stacker or as discussed below, with particular reference to figure 3, it has a shaft and hole joint. 20 The baler (3) travelling in the direction (5) harvests hay or straw which passes into the baling portion of the baler shown by the arrow (11). This is used to form the first bale (13) shown in dotted outline. 25 Figure 2 shows the bale stacking method used in the bale stacker (1) in a general manner. The first bale (13) is shown correctly positioned in the bale stacker (1). The second bale (15) is pushed along by the third bale (17) in the direction of the arrow (19) and on top of the first bale (13). The second bale (15) is pushed towards the rear of the bale stacker (1) until it triggers the sensor assembly (21) which results in the 30 delivery of the stacked bales (23) on the ground. 02/07/10jb 18090 cap specification.doc,I I - 12 Figures 3 to 9 depict in more detail various steps in the process of stacking bales and delivering stacked bales. Figure 3 shows the rear of the baler (3), the bale ramp assembly (7), the baler hitch 5 attachment (9) together with the bale stacker (1). The first bale (13) from the baler (3) is pushed along an upwardly inclined bale platform (25) of the ramp assembly (7) at the rear of the baler and over the front of the bale stacker (1). The ramp assembly (7) comprises the ramp platform (25) which is pivotally attached by bolts (26) to the ramp support (27). The ramp assembly (7) includes a pair of chains (29) attached to 10 fastening points (30) located on both sides of the ramp platform (25) and attached to fastening points (31) on the baler (3). The length of the chains can be adjusted in order to change the pitch of the ramp. The ramp assembly (7) includes a roller (33) at the end of the ramp platform (25). 15 The ramp platform (25) provides underlying support for most of the bale (13). The length of the bale ramp platform (25) allows a low angle relative to the horizontal which facilitates the delivery of bales into the bale stacker (1). The roller (33) at the end of the ramp platform (25) is located above the height of a bale when loaded in the bale stacker. 20 In this arrangement it can be necessary to have a long draw bar (40) as part of the bale stacker. A short draw bar can be used with a short ramp platform (25) configuration, if baler can deliver the bales into bale stacker in that configuration. The draw bar (40) can be a fixed part of the frame of the bale stacker. Alternatively 25 the length of the draw bar may be adjustable by having the draw bar fit within a sleeve and held in a fixed position by bolts or other durable fastening means. The bale stacker (1) is attached to the baler (3) by a central hitch (34). The baler part of the hitch comprises shaft (35) attached to a support member (36) which is fixed to 30 the baler (3) by bolts (38). As shown the hitch support member (36) includes the ramp support (27) at an upper portion of the member. This is done for convenience in 02/07/10jb I8090 cap specificabon.doc,12 -13 fitting, the ramp support (27) can be separate from the baler part of the hitch assembly. The bale stacker part of the hitch includes the tow bar (37) has an aperture through 5 which passes the shaft (35). The bale stacker (1) is also attached by a pair of chains (39) located either side of the central hitch. The bale stacker (1) includes an empty bale support platform (41). The rear section (43) of the platform (41) is raised and the front section (45) is lowered. The stacker 10 includes a releasable platform restraint assembly (47) which has engaged the support platform. The restraint assembly includes a spring (49) which acts on a moveable release bar (51). One end of the spring (49) is contained by a flange attached to the release bar (51). The bar (51) is fully extended above the forward bale barrier (53) located at the front end of platform (41). The forward bale barrier (53) prevents the 15 forward motion of a bale on the platform. The extension of the release bar (51) over the bale barrier (53) prevents the upward movement of front bale restraint and associated platform (41). The releasable platform restraint (47) is operatively connected to the stacked bale 20 sensor assembly (21) by the chain (55). In figure 4 the first bale (13) has travelled further along the ramp platform (25) on the baler (3). It is pushed along by contact with the second bale (15) from the baler. There has been no change in the position of the platform (41) in the bale stacker (1). 25 Figures 4 to 9 depict a bale stacker with a short ramp platform (25) and short draw bar (40). In figure 4 the longitudinal section view of the bale stacker shows the axle (57) about which support platform (41) is capable of pivoting motion. The centre of gravity of 30 the platform is positioned rearward of the pivot axis so that the rear section (43) of the support platform (41) would be down, in absence of other influences. The rear section (43) of the platform (41) was raised by the action of the springs (59). The 02/07/10jb18090 cap specification.doc,13 - 14 springs are attached to the frame of the bale stacker and the platform (41). The springs (49) when extended when the rear section (43) is lowered have sufficient spring force to raise the rear section (43) of the platform (41). 5 The springs could be replaced by a weight and pulley system to achieve the same outcome. The location of the springs can be changed. Also visible in figure 4 are the bale restraint spikes (61). An upper portion of the spikes (62) extend through a portion (63) of the forward section (45) of the support 10 platform (41). The spikes (61) are releasable fitted within mountings (64) attached to the frame of the bale stacker. In figure 5, the front end (67) of the first bale (13) is shown falling down into the bale stacker and will contact the rear section (43) of the support platform (41). The 15 bale (13) is also supported by the ramp roller (33). The rear upper surface (69) of the first bale is prevented from excessive upward movement by contact with the upper bale restraint (71). In the absence of the restraint, straw bales can bounce and flip over and out of the bale stacker (1). The upper bale restraint (71) comprises a contact plate (73) fitted to a cross bar frame (75) attached to upright members (77) on both 20 sides of the frame of the bale stacker. In figure 6, the first bale (13) has completely left the ramp assembly of the baler and is now fully within the bale stacker and on the platform (41). The end of the first bale (13) closest to the bale stacker has fallen with some force onto the upper portion of 25 bale spikes (62). The upper portion of the bale spikes (62) help to hold the first bale in position and prevent movement of the bale toward the end of the bale stacker. The second bale (15) is being pushed out from the baler (3) by the third bale (17), over the ramp platform (25) and on top of the upper surface of the first bale (13). The 30 upper surface (69) of the first bale (13) located towards the front of the bale stacker supports the second bale (15) together with the ramp platform (25). 02/07/10jb18090 cap specification.doc,14 - 15 In figure 7, the second bale (15) has been pushed by the third bale (17) from the baler and off the ramp platform (25) and roller (33), and is completely on top of the first bale (13). The end (81) of the second bale facing towards the rear of the bale stacker has triggered the bale sensor (21) by sufficiently moving the arm (101) of the sensor. 5 The motion of the sensor arm (101) pulls the chain (55) in the direction shown by arrows (83) and (85). This pulls one side of the rocker bar (87) towards the rear which moves the other side of the bar (89) in the direction of the arrow (91). The other side of the rocker bar (89) is operationally connected to the moveable release bar (51). The rearward movement of the chain (55), moves the other side of the 10 rocker bar (89) forward, drawing back the moveable release bar (51) through an aperture in the release support frame (52) and compressing the spring (49) between the release support frame (52) and the release bar flange (50). This movement of the release bar (51) disengages the release bar (51) from the top of the forward bale barrier (53) of the platform (41). 15 In figure 8, the withdrawal of the release bar (51) has permitted gravity to tilt the rear section (43) of the platform (41) downward whilst raising the front section (45) about the axle (57). The springs (59) (not shown in figure 8) are insufficient to keep the rear section (43) of a loaded platform (41) raised against the weight of the bales. 20 As shown in figure 8, the front section (45) has been raised up from the front section support member (44) attached to the frame of the bale stacker. This support member (44) limits the downward motion of the front section (45) of the platform (41) and supports the weight of loaded bales. 25 With the raising of the front section (45) the bale spikes (61) no longer extend though the platform (41) and thus no longer limit the movement of the first bale (13). The lower surface of the end of the first bale at the rear of the bale stacker comes into 30 contact with the ground. This contact between the ground and the bale together with the rearward slope of the platform and the forward motion of the bale stacker will 02/07/10jb18090 cap specification.doc,15 -16 result in depositing of the two stacked bales (13,15) off the bale stacker onto the ground. Figure 9 shows the stacked bales together with the empty bale stacker (1). The 5 springs (59) contract applying a lifting force, as shown by the arrows (93), to the rear section (43) of the platform. The spring force raises the rear section of the platform to the raised position, shown by the arrow (95). Simultaneously the front section (45) of the platform is lowered about axle (57) until limited by the front section support member (44). Once the top of the forward bale barrier (53) moves below the release 10 bar (51) the spring (49) expands and repositions the release bar (51) above the forward bale barrier (53). It also moves the rocker bar and the chain (55). With reference to figures 10 to 14, the depicted bale stacker has an upper bale restraint (71) which includes additional guide members (78, 79). These additional 15 guide member act to resist sideways movement of the bale. In use the guide members (79) extend around the sides of part of the ramp platform (25). The bale support platform (41) includes a substantial flat sheet (42) affixed to framing members. The sheet (42) may be formed from sheet metal or any material 20 capable of supporting the weight of two bales. The sheet (42) can be a plywood sheet. The sheet (42) is covered with a nylon polymer cover (46) to reduce the surface friction of the sheet and make it easier to slip stacked bales from the bale stacker. 25 It is not necessary for the sheet (42) to cover the entire bale support platform (41). As shown in figure 10 the rear section of the bale support platform (41) includes removable extension bars (48) for supporting a bale. These bars permit the size of the bale support platform (41) to be adjusted for use with square bales of different lengths. Also the section of the bale support platform (41) forward of the spikes (62) 30 is not covered. 02/07/10jb18090 cap specification.doc, 16 - 17 The bale stacker includes a front jockey wheel assembly (94) for supporting the weight of the bale stacker when it is not hitched to a baler. The jockey wheel assembly includes mounting fastened to the frame of the bale stacker, a jockey wheel on a threaded shaft in the mounting, the distance between the jockey wheel and the 5 ground being adjustable by turning the jockey wheel handle. Figure 14 also shows the spike support beam (140) to which the spike mounts (64) are affixed to the frame. 10 Figures 15 and 16 show the caster wheel assembly used with the bale stacker. The wheels can be locked in alignment by pin (95) which fits within apertures (97) and (99). The wheels are locked in alignment as shown in figure 16 when the machine is used as a bale stacker, but it can be useful to remove the pin (95) as shown in figure 15, when repositioning the bale stacker around the farm. When removed the pin (95) 15 can be stored in the pin holder (96) affixed to the frame. Figures 17 and 18 show the bale sensor assembly (21). The sensor assembly comprises an arm (101) attached to the frame of the bale stacker by the threaded shaft (103) which in turn fastened to the sensor body (104). The arm is capable of 20 rotation about the shaft (103). The sensor body (104) includes clamp plates (106) and bolts (108) which are used to hold to the body (104) to the frame of the bale stacker. The body (104) is held in place relative to the end of the frame by the threaded shaft (114). The shaft (114) is fastened to a flange (110) attached to the frame of the bale stacker. The shaft (114) passes through an aperture in a lower portion of the body 25 (116) and the body (116) is held in place by the locking nuts (114). Figure 17 shows a cutaway view of the lower body (116). The sensor assembly include a stop (105) to prevent the fixed end of the arm (101) moving past the stop. The free end of the arm is fitted with wheel (107) for contact 30 with the end of a stacked bale. The arm (101) is connected to the chain (55) which in turn is connected with the releasable platform restraint (not shown in these figures). 02/07/10jb[8090 cap specification.doc,17 - 18 The releasable platform restraint includes the spring (49) which also operates as a return spring for the sensor arm via the chain (55). Figure 17 shows the sensor in the normal state. The end of the bale has not moved 5 the arm (101). Figure 18 shows the operation and triggering of the sensor. The rearward motion of the bale has pushed the wheel (107) and with it the arm (101) out of the path of the bale. As the arm (101) is rotated it pulls the chain (55) towards the rear of the bale 10 stacker in the direction of arrow (109). With sufficient motion of the chain, the platform restraint is released. The point at which the sensor triggers the operation of the platform restraint can be finely controlled by adjusting the position of the sensor body (104) along the 15 threaded shaft (112) and relative to the fixed flange (110). The sensor is reset and the arm (101) returned to its normal position after the stacked bales have left the bale stacker. When the spring (49) re-engages the release bar (51) with the top of the bale barrier (53), the other side of the rocker bar (89) is moved 20 toward the front of the bale stacker, and thereby moving the chain (55) and sensor arm (101) towards the front of the bale stacker. Figures 20 to 29 relate to an optional bale stopper (120) for use with the bale stacker of the invention. The bale stopper (120) can replace one of the removable extension 25 bars (48). In figures 10 to 14, the central extension bar has been replaced with the bale stopper (120). Figures 20 to 23 show different views of the bale stopper in the bale stopping configuration. The bale stopper includes a removable extension bar (121) which is 30 fastened to the rest of the bale support platform by bolt (122). As shown in figure 14, the length of the extension bar (121) is shorter than the other extension bars (48). 02107/10jb8090 cap specificadion.doc,18 -19 The bale stopper also includes a U shaped bale block member (123) which is rotational fastened across the arms of the U to the extension bar (121) by the bolt (124). The base (125) of the U shaped block member (123) prevents the rotation of the base (125) past the lower surface of the extension bar (126). 5 The top surface (128) of the U shaped member (123) is the surface which engages with a bale and can resists the motion of a bale towards the free end of the extension bar (121). 10 One arm of U shaped member (123) is rotationally fastened by bolt and fastener (129,130) to a link arm (131) which in turn is fastened to chain (132) by the D shackle (133). The nut fastener (130) limits the rotational motion of the U member (123) by contact with the upper surface of the extension bar (134). The D shackle (133) prevents the rotation of link arm (131) beyond the extension bar (121), by 15 contact with the lower surface of the extension arm (126). The U shaped member (123) includes a spacer (135) which prevents the arm (131) from contacting the bolt (124). The bolt (129) passes through the spacer (135) and the spacer continues down one side of the U member as the spacer guide member 20 (136). Figure 24 show the bale stopper in the release configuration. The bale engaging ends (128) of the U shaped member (123) have rotated upward and then rearward about the bolt (124). The lower rounded edge (137) in figure 20 has been raised and is the 25 leading bale contacting edge. The rounded edge (137) facilitates the motion of the bale over the repositioned U shaped member (123). The link arm (131) is guided by the spacer and guide (135,136) and covers the end of the bolt (124). A side protrusion (127) at the base of the U shaped member engages 30 and lifts the link arm (131) as the base (125) of the U shaped member is raised towards the lower face (126) of the extension bar (121). 02/07/10jb18090 cap speciFication.doc.19 - 20 With reference to figure 13 and 14, the chain (132) passes under most of the bale support platform, passes through the open forward section of the support platform, passes around a guide shaft (138) affixed to the bale stacker frame, and the end of the chain is affixed to the frame at point (139). 5 Figures 25 to 29 are schematic representations which show the configurations of the bale stopper (120) and the method of operation. The link arm (131) is shown, in a cutaway view so as to show the rotation of the U shaped member (123). 10 When the bale stacker is empty (figure 29) or is in the process of being loaded with the bale (140) (figure 25), the bale stopper (120) is in the disengaged, stopping configuration. The bale stopper has the appearance shown in figures 20 to 23. In this configuration the link arm (131) is at rest and the chain (132) should have 15 some slack. In figure 26, the bale is fully on the bale support platform. As the end of the bale (140) facing the end of the bale stacker was pushed rearward, the bale pressed against the bale engaging surface (128) of the U member (123). The rearward motion 20 rotated the bale engaging surface (128) of U member (123) about its axis of rotation. The motion repositions the bale engaging surface of the U member (123) so that it extends into the bale and restricts further rearward motion of bale. Further rearward rotation of the U member (123) is prevented by the link arm (131) 25 and chain (132), which is now taut from the fixture point (139), shaft (138), across the base of the tilted support platform to the end of the link arm (131). The bale stopper (120) is now in the engaged, stopping configuration. The bale stopper remains in this configuration until the bale support platform tilts to release the stacked bales. 30 In figure 27 the bale support platform has tilted so that the rear facing portion of the platform is downward. This is represented by the downward position of the bale. The 02107/10jb18090 cap specification.doc,20 -21 distance between the end of the link arm (131) and the shaft (138) was reduced as the end of the platform was lowered. As a result the slack in chain (132) permitted the bale engaging surface of U member to continue with its rotation towards the rear of the bale stacker. The rotation is assisted by the weight of the bales sliding down the 5 tilted platform. The bale stopper is in the bale release configuration, as shown in figure 24. In figure 28 the stacked bales have been deposited onto the ground and the rear of the support platform has tilted upward. As the platform tilts the distance between the end 10 of the link arm (131) and the shaft (138) increases, pulling the end of the link arm (131) towards the front of the bale stacker. This force rotates the bale engaging end of the U member (123) towards the front of the bale stacker and upright. In figure 29, the weight of the chain (132) has topped over the bale engaging end of 15 the U member (123) towards the front of the bale stacker. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or 20 group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form or suggestion that the prior art forms part of the 25 common general knowledge in Australia. 02/07/10jbI8090 cap specification.doc,21

Claims (17)

1. A bale stacker for square or rectangular hay or straw bales comprising: a) a longitudinally elongated frame having a bale receiving front end and a 5 rear end and two sides; b) a hitch at the frame front end for attachment to a rear delivery baler; c) a pivoting bale support platform for supporting bales received by the bale stacker, the platform pivotally connected to the frame about an axis substantially perpendicular to the longitudinal axis of the frame, the axis 10 located forward of the centre of gravity of the unloaded support platform, the platform having a front section toward the front end of the frame and forward of the pivot axis, and a rear section toward the rear end of the frame and rearward of the pivot axis; d) a spring connected to the frame and platform, the spring capable of raising 15 the rear section and lowering the front section of an unloaded support platform about the pivot axis but not capable of doing the same when the support platform carries a bale stacked above another bale; e) a releasable platform restraint connected to the frame and capable of engaging the platform when the rear section of the support platform is raised 20 and, when engaged, the restraint prevents the downward pivoting motion of the raised rear section of the support platform until the restraint is disengaged; f) a stacked bale sensor capable of sensing an end of a stacked bale when the stacked bale end is at or near the rear end of the elongate frame; g) the stacked bale sensor being operationally associated with the releasable 25 restraint, whereby the restraint is disengaged after the sensor senses a stacked bale end at a desired position in the bale stacker; h) side bale restraint members at the sides of the frame capable of limiting sidewise movement of received bales. 30

2. The bale stacker according to claim 1 wherein the frame includes one or more upwardly extending bale engaging spike(s), which upwardly protrude through the front section of the support platform when the front section of the support platform is 02/07/10jb28090 cap specification.doc,22 -23 lowered and do not protrude through the support platform when the front section of the support platform is raised.

3. The bale stacker according to claim 1 or 2 further including an upper bale 5 restraint for directing bales received from the baler toward the support platform and restraining received bales from excessive up movement.

4. The bale stacker according to any one of claims 1 to 3 wherein the pivoting support platform includes a frame and a substantially flat support surface fastened to 10 the top of a part of the frame.

5. The bale stacker according to claim 4 wherein the support surface is metal sheeting or plywood. 15

6. The bale stacker according to claim 4 or 5 wherein a polymer sheet cover is affixed to the top of the support surface.

7. The bale stacker according to any one of claims 1 to 6 wherein the spring is connected to the rear section of the support platform and to the frame of the bale 20 stacker above the support platform.

8. The bale stacker according to any one of claims 1 to 7 wherein the bale sensor is a mechanical device. 25

9. The bale stacker according to claim 8 wherein the sensor includes a rotating lever arm with an operationally associated return spring, wherein an end of the arm is capable of movement from a position in the path of the stacked bale towards the side of the frame of the bale stacker as an end of a stacked bale travels rearward, the sensor being operationally associated with the platform restraint and capable of 30 disengaging an engaged releasable platform restraint when the arm is in a position associated with having appropriately stacked bales. 02/07/10jb18090 cap specification.doc,23 - 24

10. The bale stacker of claim 9 wherein the arm is operationally associated with the releasable platform restraint by a linking chain or rope and the sensor arm return spring is part of the platform restraint. 5

11. The bale stacker of claim 10 wherein the sensor is capable of being repositioned along a side of the frame of the bale stacker and thereby permits control over the operation of the releasable platform restraint.

12. The bale stacker of any one of claims I to 11 for use a baler fitted with a bale 10 ramp for delivery of bales into the bale stacker, wherein the bale stacker includes bale guide members at the forward sides of the bale stacker near the location of the bale ramp to control the sideways movement of bales leaving the ramp.

13. The bale stacker of any one of claims I to 12 wherein the support platform 15 includes one or more removable extension bars which extend rearward and which are capable of providing support for a bale resting thereon.

14. The bale stacker of any one of claims 1 to 13 further including a bale stopper at or near the rear of the support platform for reducing or preventing a lower bale 20 from sliding out of the bale stacker.

15. The bale stacker of claim 14 wherein the bale stopper operates to restrict bale movement when the rear section of the support platform is raised and disengages when the rear section of the support platform is lowered. 25

16. The bale stacker substantially as hereinbefore described with reference to the figures.

17. The bale stacker of any one of claims 1 to 16 when hitched to and towed 30 behind a baler. 02/07/10jb 18090 cap specification.doc.24