CROP GATHERING APPARATUS FOR A CROP HARVESTER

The invention relates to crop gathering apparatus for harvesting machines such as combine harvesters, the apparatus including a table to receive cut crop, said table defining a gathering width of the apparatus, a crop conveying belt, said belt being mounted on said table and positioned in a gathering width so as to convey cut crop rearwardly, and rotatable end rollers for said crop conveying belt, said end rollers being spaced apart and said belt being trained round the end rollers in an upper run and a lower run.

The Powerflow (registered trade mark) header for combine harvesters was introduced by Massey Ferguson (registered trade mark) in the 1980s and proved successful with farmers particularly in Western Europe where cut cereal crops are particularly dense. The Powerflow header includes a number of rubber conveyor belts between the cutterbar and the cross feed auger. The belts convey the cut crop rearwardly whilst also serving to lay the crop flat before being fed into the cross feed auger. This provided a more even feed for the feed auger thus improving threshing quality and capacity.

United Kingdom patent GB-1 ,501 ,639 describes the arrangement of the Powerflow header and reference to this publication is invited. Each crop conveying belt is supported by two end rollers mounted on the table transversely at the front and rear of the conveyor run. Tensioning mechanisms are also provided to maintain a desired tension in the rubber belt. At least one of the end rollers is driven by power derived from the harvester's engine.

Due to the relatively high width-to-length ratio of the belts, maintaining alignment can be problematic during operation. The aforementioned patent describes guide rollers which act upon the lower run of the belt at the transverse edges and are shaped to discourage the belt from moving out of alignment along the end rollers. Despite this solution to maintain alignment of the conveyor belts there still remains a desire to improve upon the mechanism to maintain alignment of the belts. Even today operators are faced with non-trivial down time to realign the belts during harvesting.

CONFIRMATION COPY It is therefore an object of the invention to simplify the means by which conveying belts in crop gathering apparatus are guided to reduce down time of the machine.

In accordance with the invention there is provided crop gathering apparatus for a harvesting machine comprising a table to receive cut crop, said table defining the gathering width of the apparatus, a crop conveying belt, said belt being mounted on said table and positioned in the gathering width so as to convey cut crop rearwardly, rotatable end rollers for said crop conveying belt, said end rollers being spaced apart and said belt being trained round the end rollers in an upper run and a lower run, and belt guide means comprising a sprocket mounted for rotation to the table and meshing with sprocket engaging means disposed along an edge of the belt. The sprockets provide a superior means of guiding the belt thus dispensing with the need for complex and expensive guide rollers. Furthermore, the amount of downtime is significantly reduced because adjustment is rarely required once set up.

Preferably the sprockets are mounted to roller shafts which carry the end rollers. Advantageously, this dispenses with the need for dedicated shafts to support the sprockets as the roller shafts already exist. By mounting the sprockets on the same shaft as the end rollers, power to drive the belt is also conveyed via the sprockets thus reducing stresses upon the driven end roller.

Preferably each sprocket engaging means engages two sprockets each being carried on a respective roller shaft, for example at the front and rear.

A first of the end rollers may have a driving torque applied thereto wherein a second of the end rollers is passive and rotates through forces delivered by the crop conveying belt. The driving torque is preferably conveyed by a driven sprocket (separate from the guiding sprocket) mounted on a roller shaft which also carries an end roller. However, it is envisaged that alternative means of conveying the driving torque may be employed.

In a first embodiment, the belt guide means comprises two roller chains each attached to a lateral edge of the belt. The sprocket-roller chain combination advantageously provides a robust mechanism to guide the belt. The roller chains are preferably attached to the belt by a plurality of brackets spaced along the edge of the belt, the brackets securing to the belt by means of bolts disposed through the belt material. Alternative means of securing the chains to the belt are, of course, envisaged and may include, by way of example, rivet connections or gluing.

In a second embodiment, the belt guide means comprises a set of perforations disposed along each lateral edge of the belt. In this case, the sprocket(s) meshes directly with the belt through perforations (or holes) formed along the edges of the belt. Advantageously, the provision of perforations in the belt dispenses with the need for roller chains which saves on cost.

The crop conveying belt preferably comprises a releasable seam for enabling removal of the belt, the seam comprising two interleaved sets of loops disposed along respective edges of the belt to be joined, wherein the seam is secured by a rigid bar inserted through the interleaved sets of loops. Advantageously, this provides a simple means to split the belt for maintenance without the need to remove the end rollers. Furthermore, where roller chains are provided, the ends of the rigid bar can be connected to the respective roller chains to better distribute the driving forces upon the conveyor belt.

The crop conveying belt preferably comprises a plurality of transverse ribs on the outer surface thereof. The ribs assist in the conveyance of the crop material. Each rib preferably presents an open-ended channel through which a respective rigid bar is inserted, each rigid bar preferably being secured at its ends to the roller chains (if provided). Each rib preferably comprises a strip of flexible material, such as rubber, bonded to the crop conveying belt along the long edges of the strip.

Rigid bars inserted through the channels presented by the ribs provide an ideal means for connecting the roller chain(s) to the conveyor belt whilst also distributing the driving power across the full area of the belt. Advantageously, this minimises high stress ^' regions which are otherwise susceptible to failure thus improving the robustness of the construction.

The aforementioned seam having interleaved sets of loops preferably provides one of said ribs within a set of evenly spaced ribs.

The crop gathering apparatus may comprise a plurality of crop conveying belts mounted on said table and positioned in the gathering width side-by-side, each crop conveying belt having respective pairs of end rollers and guide means. In this arrangement a first end roller of one belt has a driving torque applied thereto, and a second end roller associated with an adjacent crop conveying belt may derive torque from that first end roller. Therefore, only one input source of torque is required and is distributed in a series manner from one conveyor belt to the next.

Torque may be conveyed from one conveyor belt arrangement to an adjacent conveyor belt arrangement by means of a pair of drive transfer sprockets mounted to respective shafts associated with the conveyor belts, wherein a common torque transfer chain engages both drive transfer sprockets. However, other forms of driving the individual belt arrangements can be employed.

Further advantages of the invention will become apparent from reading the following description of specific embodiments of the invention with reference to the appended drawings in which:-

Figure 1 is an isometric view of part of a harvesting header which includes crop gathering apparatus in accordance with the invention and shown with the reel system removed for clarity;

Figure 2 shows a vertical section through the harvesting header shown in Figure 1 ;

Figure 3 shows a perspective view of part of the crop gathering apparatus included in the header of Figure 1 and in accordance with a first embodiment of the invention;

Figure 4 shows a perspective view of the crop gathering apparatus of Figure 1 in accordance with the first embodiment of the invention and shown with a protective guard and one crop conveying belt removed;

Figure 5 shows a perspective view of part of one crop conveying belt in accordance with the first embodiment of the invention;

Figure 6 shows an isometric view of one crop conveying belt in accordance with a first embodiment of the invention shown with the roller chain removed for clarity and showing a transverse seam; Figure 7 shows a perspective view of part of one crop conveying belt with a roller chain secured thereto in accordance with a second embodiment of the invention; and,

Figure 8 shows an isometric view of one crop conveying belt in accordance with a third embodiment of the invention.

With reference to the drawings, a header for a combine harvester is illustrated which is employed for the harvesting of cereal crops for example. It should be appreciated that the header is shown in isolation from the combine harvester but the attachment thereof is well known in the art and will not be described any further.

The crop gathering apparatus in the form of a harvesting header 10 comprises a leading cutterbar 12 which includes a reciprocating knife as in known harvesting headers. The header 10 includes two end walls 14 (only one end wall shown in Figure 1) and a transverse table 16 which defines the gathering width of the header. A header frame 18 provides a rigid supporting structure for the end walls 14 and table 16 and also provides a rear wall 20.

Mounted upon the table 16 are three crop conveying belts disposed side by side and serving to convey the cut crop rearwardly from the cutterbar 12 to a transverse feed auger 22. Figure 1 shows the left-hand belt 24 and part of the centre belt 25. The right-hand belt is out of view.

The transverse feed auger 22 has a construction known in the art which includes a rotor core 26 with screw flighting 28 mounted thereto. A belt and pulley drive mechanism (not shown) mounted on an end wall 14 drives the feed auger 22. Cut crop delivered to feed auger 22 is conveyed towards the centre of header 10 and fed through an opening 30 disposed in the rear wall 20 and into an elevator section (not shown) of the combine harvester.

A reel is shown schematically at 32 and is mounted to the frame 18 by a supporting structure 34. The reel 32 is of a known construction and serves to guide the harvested crop on to the table 16.

Turning attention back to the crop conveying belts 24, 25, each comprises a rectangular sheet of natural or synthetic rubber having one or more layers (not shown) of woven textile material embedded therein. Each sheet is wrapped around a front roller 36 and rear roller 38 best seen in Figures 2, 4 and 6. Each roller 36, 38 is mounted upon the table 16 by front upright brackets 40 and rear upright brackets 42 respectively by bolting or otherwise.

Each bracket 40, 42, supports an appropriate bearing to accept a roller shaft 44, 46 which carries the respective rollers 36, 38.

Also mounted upon the roller shafts 44, 46 are respective sprockets 48, 50 which engage a roller chain 52 attached to respective edges of the belt 24, 25 in accordance with a first embodiment of the invention illustrated by Figures 1 to 6. Best seen in Figure 5, each roller chain 52 has fixed to the side thereof a plurality of angled brackets 54 which are each bolted to respective ends of rigid bars 56 which span the width of each conveyor belt.

Each transverse rigid bar 56 is secured to the associated belt 24 in a longitudinal direction by respective rubber strips which extend across the transverse width of the belt 24 and provide crop conveying ribs 58. The rubber strips are each bonded along their lengthwise edges to form a channel through which the bars 56 are received.

The rectangular sheet of material providing the belt 24 is closed in a loop by a seam 60 shown in Figure 6. Respective edges of the seam 60 each comprise a set of loops 62, 64 formed from the same rubber material as the ribs 58 and disposed along the transverse length of the edges to be joined. The respective pair of loops 62, 64 interleave with one another forming an additional rib 58a. The seam is secured by a rigid bar 56a being inserted through the interleaved loops 62, 64. The additional rigid bar 56a can be secured between the associated roller chains 52 in a similar manner to the other rigid bars 56.

Advantageously, the belt 24 can be easily removed for maintenance by simply disconnecting rigid bar 56a from the roller chains 52 and removing from the seamed edges 60.

Although the above belts 24, 25 include a releasable seam, it is envisaged that this may be omitted and, instead, have an endless, seamless belt without deviating from the scope of the invention. The above description relates to left-hand belt 24 as shown in Figure 1. However it should be appreciated that centre belt 25 and right-hand belt (not shown) adopt a similar construction to that described above.

The conveyor belts 24, 25 are driven via the rear end roller 38 wherein a drive mechanism (not shown) delivers torque to the left-hand rear roller 38. This drive torque is transferred to the centre conveyor belt 25 by means of a pair of drive sprockets 66, 68 (Figure 4) which are coupled by a common chain. Torque is transferred from the centre belt 25 to the right-hand belt in a similar manner.

Figure 7 illustrates an alternative means of securing a roller chain to the transverse edge of a belt. Here, roller chain 152 has attached thereto a plurality of angled brackets 154 which are each bolted to the edge of the belt 124 through holes provided along the edge thereof. A cost saving is provided over the above-described assembly by dispensing with the transverse rigid bars 56, but perhaps at the expense of reduced robustness in the belt construction.

To provide further cost savings the guiding roller chains can be dispensed with entirely with the provision instead of perforations in the belt material which are engaged directly by the guiding sprockets as illustrated in Figure 8. The edge of belt 224 is provided with a set of spaced holes or perforations 270. Each of the front and rear rollers is provided with a sprocket 248,250 each having teeth that engage with the holes 270. In a similar manner to the above-described system, the rear roller is driven via a driven sprocket 266 mounted on the same shaft. In turn, this drives the belt 224.

In summary there is provided crop gathering apparatus for a harvesting machine which comprises a table to receive cut crop. The table defines the gathering width of the apparatus. A crop conveying belt is mounted on the table and positioned in the gathering width so as to convey cut crop rearwardly. Rotatable end rollers are provided and spaced apart wherein the belt is trained round the end rollers in an upper run and a lower run. Belt guide means are provided comprising sprockets each meshing with respective sprocket engaging means in the form of roller chains attached one to each lateral edge of the belt or sets of perforations provided along said belt edges. The belt guide means may comprise two roller chains attached one to each lateral edge of the belt, and sprockets each engaging a respective one of said roller chains and mounted for rotation to the table.