"BACKGROUND ART Open top balers offer many benefits when compacting fibrous materials, where materials are compacted into a bale for storage, transport and handling. Such baling operations are performed by a variety of press types. Most press types are of a vertical nature where a pressing plate moving in a vertical plane where materials are placed in a fixed sized hopper"a door closed". The pressing plate then forces the materials into a lower hopper for compaction. Many open top balers have a rotary wheel where materials are rolled and munched to form a compacted bale. Many open top balers make poorly shaped bales which create transport difficulties.

Open top balers have experienced exceptance problems in many places on account of possible accidental entry from overhead and possible associated injuries.

"DISCLOSURE OF THE INVENTION" It is therefore an object of the present invention top provide a pressing system which will go towards obviating or minimising the foregoing disadvantages in a simple yet effective manner.

The present invention therefore provides a baling press comprising of an enclosure into which material is to be compressed. A hopper located above the mouth of the enclosure and positioned to feed material to be baled into the enclosure, a plurality of pressing fingers extending into the hopper through vertical slots in the hopper walls. Actuation means arranged to move the fingers downwardly from an elevated position in the hopper to a lower position adjacent to the mouth of the enclosure, then to return the fingers to an elevated position.

The pressing mechanism consists of pressing fingers pivotally attached outside hopper walls to main arms which in turn are pivotally attached to extensions of the pressing enclosure.

The said actuation means is linked to the pressing fingers in such a manner as to cause them to stand rigidly outwards into the hopper when they are moved downwardly.

The said actuating means is so linked to the pressing fingers to cause them to retract from the hopper when moved upwardly. The mechanical geometry is so arranged to ensure that the fingers withdraw through the slotted wall with

minimal disturbance to materials in the upper holding chamber.

The utility of this pressing action allows many useful control functions to be integrated into the electronic control package. Further there is scope to incorporate sophisticated safety procedures and detection systems. During a pressing cycle the pressing fingers follow a path inside the hopper. The pressing fingers withdraw from the hopper on the upward path. Presses are equipped with an upper and lower door for bale removal. The pressing fingers are in a staggered formation to give full bale top coverage yet maintaining generous clearance between the opposing finger tips.

The press is fully electronically controlled with a PLC controller. Situated in the upper holding chamber are infra red sensors which detect material initiating a cycle each time the infra red beam is broken. To protect the open top system by accidental entry by a person and possible injury as a result of activating the machine via the infra red beam. A PIR detector situated above the open hopper. Situated in such a manner as not to interfere with the loading of the hopper. The PIR detector is linked to the PLC controller to protect by closing the machine down when entered by a person or part thereof.

"BRIEF DESCRIPTION OF DRAWINGS" Fig. 1 elevation view of press showing finger in several positions and the path of the fingers during one pressing cycle.

Fig. 2 elevation view of press showing fingers up and retracted.

Fig. 3 elevation view of press showing fingers up and extended.

Fig. 4 elevation view of press showing finger part way down.

Fig. 5 elevation view of press showing fingers down.

Fig. 6 elevation view of finger assembly unit.

Fig. 7 part perspective view of press showing fingers entering the upper chamber through the slotted press wall.

Fig. 8 over head view of the staggered arrangement with the fingers down.

Fig. 9 press sketch.

Fig. 10 passive infra red mounting Fig. 11 abstract drawing

"MODE FOR CARRYING OUT THE INVENTION" The compactor consists of a base and two sides of the pressing compartment constructed as an integral unit, the other two sides of the pressing compartment are pivotally attached. The left and right sides are provided with abutments onto which the pressing assembles pivot. The left and right sides and the back have a structure attached to their upper edge which forms a hopper, a secondary door is hinged above the pivotally attached front side.

The compactor is powered by a hydraulic system with all functions monitored and controlled by electronics. Two hydraulic cylinders are supplied which power the pressing assemblies, a third cylinder which powers the bale ejection mechanism.

All compressible materials require some form of retention system when compacted and removed from the compactor. In many applications ropes, strings, strap or wire placed in a plurality of places around the bale is sufficient.

The press has been designed particularly, though not solely for applying string ties around the bale. The string is supplied on rolls and placed in a holder on the side of the press, the end of the string is then threaded through the string lock unit, sufficient string is drawn through to allow it to be placed under a clip situated on the floor of the baler. The string lock is situated on the top right hand side of the baler hopper and is actuated by the top door. When the top door is opened the twine lock releases the twine allowing it to be drawn through for restringing. When the top door is closed, the twine lock locks fastening the twine preventing it being drawn into the baler with the material flow. In fig. 1 the compactor consists of a hopper 1, front door 2 and a upper secondary front door (not shown), compressible materials can be loaded into the hopper 1 for compaction by either opening the secondary front door or placing the material over the top directly into the hopper 1.

When the power is switched on, the electronics disable all detection systems that cause the compactor to automatically initiate a pressing cycle. The electronic controller has up, down and eject switches. If we assume the compactor is positioned as shown in figure 3, then the down button must be pressed to commence operation. The electric motor immediately starts but all movement of the press is disabled for 4 seconds, thus giving an audible warning period. The motor continues to run for 16 seconds after the completion of

any operation and during this time the 4 seconds operation delay is disabled. Once the motor has stopped the 4 second delay is enabled again. The compactor is equipped with a keyed ignition.

In the preferred form of the invention the passive infra red detector is incorporated into the open top baler and positioned, situated and directed in such a manner so as to provide an electronic curtain for the open top of the baler.

Referring to fig. 10 the baler is equipped with detachable framework (13) attached to this frame work is a special shaped adjustable shield (15), mounted in this shield is a passive infra red detector. The shield (14) is so constructed so as to direct the activity of the PIR into the balers upper hopper only with no activity from the Passive Infra Red device outside the baler confines. The entry of material into the baler hopper will have no effect not registering with the PIR. Many standard electronic curtains respond to movement only and as such are unsuitable for this particular application.

The PIR unit responds to a combination of movement and body heat making it ideal for detection of a person or part thereof. The PIR system is coupled via an electrical lead to the baler PLC controller so that when the PIR is activated the controller closes the function of the baler down irrespective of the position of the balers pressing mechanism may be at the time. The PIR curtain on account of its particular means of application creates a very safe system for open top machines.

If the PIR system were to fail or be removed this will render the baler electronic system inactive. The director shield (15) is adjustable to suit the various sized openings on different size and shaped machines.

The pressing means are the finger assembly units situated on either side of the press structure fig's. 1, 2,3, 4,5.

The finger assembles are attached to the baler structure via four pivot bearing (6 A). The finger assemblies are connected to the double acting hydraulic cylinders (7) at the top by a pivot lug (9) situated on the finger cluster unit (3) and attached the bottom end to the press structure (13). The hydraulic cylinders are in turn plumbed into a singular hydraulic system and are controlled by the above mentioned PLC control system. The finger assembly unit fig. 6 consists of a finger cluster unit (3) and a carrier frame (4) and a full length pivot pin (5). The finger cluster unit (3) has a plurality of staggered fingers. The two outer fingers on the finger cluster unit protrude to the rear of the cluster unit to

form the stopper contract points. The finger cluster unit is coupled together as a singular unit by a substantial hollow bar section which has on its underside (of the finger cluster unit 3) the anchor point on which the above mentioned hydraulic cylinders anchor (9).

The finger cluster unit (3) is attached to the carrier frame (4) by a full length pivot pin (5), pivot pin (5) being restrained by a split pin both ends. Welded to the carrier frame (4) are the stopper lugs (6), the stopper lugs (6) contact with the two outer finger rear protrusions. The stopper lugs (6) govern the rotational amount of the finger cluster unit (3) in both directions. On the pressing stroke the stopper contacts the finger cluster unit as in fig. 6. On the retraction or the up stroke the finger cluster unit rotates to contact the stopper (6) as in fig. 1. Fig. 3 shows the position of the finger assembly unit with the hydraulic cylinders (7) fully extended. The fingers are vertical and completely clear of the loading hopper chamber (1). At this fully extended point the spring loaded locking device (not shown) engages locking the finger cluster unit (3) and the carrier frame (4) into a rigid unit for the descending stroke, fig. 3.

When the down button is activated the double acting hydraulic cylinders begin to close drawing the rigid finger assembly fingers through the slotted walls of the loading chamber (i) fig. 7 and proceeding on the downward path sweeping well into the upper chamber fig. 4, proceeding all the way down on their compaction stroke. As the fingers travel down, they move closer together from each side until they achieve full travel on the compression stroke fig. 5. The staggered finger arrangement spanning to cover the whole bale top fig. 8. As the fingers approach each other on the compaction stroke some material is forced into the centre between the finger points which requires generous clearance between the finger points to prevent machine damage. The staggered finger arrangement fig. 8 giving both coverage and clearance.

The pressing assembly remains in the down position (fig. 5) until further materials are thrown into the loading chamber (i), the deposited materials are then detected by the infra red sensor unit situated in the loading chamber (1). The infra red sensor unit then activates the control system reversing the direction of the double acting hydraulic cylinders (7) as the hydraulic cylinders (7) commence to open on the

return (up) stroke the spring loaded latch which kept the pressing assembly rigid on their descending stroke is released causing the assembly to relax and pivot as in fig's. 1 and 2.

The assemblies remain relaxed and unlocked until fully extended as in fig. 3. Because of the relaxed action of the pressing finger assembly fig. i on account of the finger retraction path fig. 1, finally withdrawing through the slotted hopper wall (stage 2), fig. 1. Situated on both sides of the baler and attached at one end to the press structure and the other end to the finger assembly unit are position control struts 11, fig. 2. These strut units are a sealed oil charged unit which govern the function of the fingers and finger assemblies on the return (up) stroke. Internally the resistance struts have a piston unit with a value which allows the oil to flow without restriction on the descending pressing stroke offering no resistance in this direction. On the return stroke of the pressing finger assembly (up) the strut is forced closed closing off the free flow value and forcing the oil flow through another path in the piston. This pathway applying a predetermined amount of resistance, this resistance being governed by the oil flow speed.

As the finger assembly units begin to rise from a position as in fig. 5 the position control struts (lu) which are attached to the finger assembly units by a pair of anchor lugs 10, fig. 6 begin to close slowly applying only a small amount of resistance at this point of the return stroke. On account of the geometry of the finger assembly unit, the speed of return or layback of the collapsed finger assembly unit greatly increases. The greatest amount of speed being when the assembly is as in fig. 2 and correspondently the greatest amount of resistance is offered by the position control strut at this point. The increased resistance at this point fig. 2 coupled with the fact that pivot 9 having the optimum leverage point in relation to centre pivot 5. The combination of pivot location, the force applied by the hydraulic cylinder and the resistance applied in the other direction by the position control strut combine to create a rotation effect of the finger cluster unit rotating the finger cluster unit 3 to stand vertical as in fig. 2 and fig. 1. When the rotation of the finger cluster unit is complete the spring loaded lock as previously mentioned but not illustrated engages. At this point as in fig. 2 the hydraulic cylinders continue to apply force on the extended finger assembly unit overcoming the force applied by the position

control strut, which at this point has relaxed its grip on account of the decrease in its closing speed. The finger assembly is then gently pushed back until they come into contact with polymer bumpers 12, fig. 3.

The combination of the function of the position control strut and the baler geometry ensure a smooth bump free return giving the unit location stability. Fitted into the hydraulic system are pressure switches which are linked into the electronic control system, these are sensitive and adversely effected by pressure spikes in the hydraulic system. The double acting hydraulic cylinder (7) are regenerated on the return stroke to speed up their return and as such can create severe pressure spikes in the hydraulic system when the pressing finger assembly reaches the position as in fig. 2. The position control struts ensure a smooth spike free return on account of positioning and timing.