GB2081312A - Knotters - Google Patents

Abstract

A knotter (24) particularly for a baler, comprises a twine holder (63) operable to hold, during a knot-tying operation, a primary portion and a secondary portion of twine in which a knot is to be tied and including spaced apart, generally coaxial flanges (90 to 93) rotatable about a first axis (64) and at least one substantially stationary twine retainer finger cooperable with the flanges (90 to 93) to hold the primary and secondary portions of twine, and a rotary billhook (66) rotatable about a further axis (99) to which it is inclined, and operable to tie the knot in the primary and secondary twine portions, the first and the further axes extending parallel to each other. The twine holder is driven intermittently from the bill hook shaft by a Geneva mechanism (67). <IMAGE>

Description

SPECIFICATION Knotters This invention relates to knotters, i.e.

mechanisms for tying knots, for any applications but for convenience, the invention will be discussed in relation to agricultural baling !nachines in which bales of hay or straw, for example are formed and secured by flexible material in which knots are tied by a knotter.

The terms "forward", "rearward", "left" and "right" when used in connection with the baler and/or components thereof are determined with reference to, and by facing in, the direction of operative travel of the baler in the field. The leading and trailing ends of the bales are determined with reference to the direction of movement thereof in the bale chamber. Since during the formation of a bale the latter is advanced in a rearward direction of the machine through the bale chamber, the leading ends of the bales face rearwardly of the machine.

In conventional hay balers, hay, straw and similar crop material that has been previously cut windrowed or swathed, is picked up from the ground by a pick-up unit and fed in successive batches or charges into an elongated bale chamber in timed sequence with a reciprocating plunger. The plunger compresses the material into bales and, at the same time, gradually advances the bales towards the outlet of the bale chamber.

As the bales reach a predetermined length as determined by a metering device, a knotter is actuated which wraps cord, twine or other flexible tie material around the bale and secures the ends of the tie material together.

In a typical baler a knotter is mounted on the bale chamber above a slot therein, the knotter comprising a twine holder from which twine extends to encircle a bale. During the baling operation, the leading strand of twine is held by the twine holder and extends forwardly across a twine retainer finger and a billhook and then in front of the bale. The twine retainer finger supports the strand so that it does not bear forcefully against the billhook. A needle is involved in completing the encirclement of twine around the bale and, when advancing, the needle lays a trailing strand across the twine retainer finger, bill hook and twine holder. A twine finger captures these strands of twine and positively positions the strands against the heel of the billhook.

Thus, there are presented in a certain zone a pair of twine portions or strands lying alongside each other and these portions are twisted into a bight by the billhook and a portion thereof is partially pulled through the bight to form a bow knot. On completion of the operation of the knotter, the twine finger returns to the initial position. The removal of the tied knot from the billhook involves mechanical stripping by a movable member which normally embodies a knife operable to cut the twine from the twine supply so that the tied bale is complete in itself.

The tying mechanism thus includes several components working in a precisely timed relationship so that theoretically the mechanism ties one knot for each bale and prepares the twine for the succeeding bale.

A knotter is inherently a relatively complicated structure, and the precisely timed operation thereof suffers at times from faulty operation. This may be due to the vibrations of the baler, the tension in the twine and the jarring of the baler as it moves through the field. The crop may be tough or resilient causing the strands of twine to jump about. Variations in the bailing twine also effect the knotting operation. Balers are operated outside and often parked in the field, whereby the knotter is exposed to all weather conditions. Also, the knotter is subjected to dirt, crop and debris resulting in abrasion and interference of operation.

At present, balers are capable of reasonably efficient operation at speeds up to a maximum of approximately eighty to ninety strokes per minute of the baling plunger. One reason for this limitation on the operation speed is that the presently available knotter cannot perform the complex tying operation at faster speeds, as the latter operation must be carried out in timed sequence with the strokes of the baling plunger.

Restraint on faster knotter operation is imposed by various cam and cam followers, complicated knotter drive means, and other oscillatory parts employed in a typical knotter which give rise to relatively high inertia forces.

Adjustments of presently available knotters are critical, with field adjustments often necessary to compensate for wear, type of twine, and operating conditions. Such adjustments occasionally require skill beyond that of the average operator, causing expensive harvesting delays.

During the knot tying operation, the billhook normally pulls a predetermined length of twine for the knot to be formed therein, in part from the twine holder and in part from around the bale just formed. In case bales at high density are formed, pulling twine from around the bale just formed is difficult to accomplish. This, in any way results in heavy loads on both the billhook and the twine holder. However, this also results in more twine length being pulled from the twine holder and occasionally it may happen that there is insufficient length of twine to produce a full size bow knot. Instead thereof, the ends of twine are pulled fully through the bight formed on the billhook and as such a double overhand knot is formed, which is not as strong a knot as a bow knot.Occasionally, it may happen that there is an insufficient length of twine in the twine holder to the extent that this twine is pulled loose from the twine holder before the knot is actually formed.

This, of course, results in a mis-tie.

It is an object of-the present invention to overcome or to attenuate one or more of the foregoing disadvantages. More particularly, it is an object of the present invention to provide a knotter mechanism for baling machines which is simple and reliable and which requires only a minimum of attention once it has left the factory.

According to one aspect of the present invention there is provided a knotter comprising a twine holder operable to hold, during a knot-tying operation, a primary portion and a secondary portion of twine in which a knot is to be tied and including spaced apart, generally coaxial flanges rotatable about a first axis and at least one substantially stationary twine retainer finger cooperable with two adjacent flanges to hold the primary and secondary portions of twine, and a rotary billhook rotatable about a further axis to which it is inclined, and operable to tie the knot in the primary and secondary twine portions, the first and the further axes extending parallel to each other.

According to another aspect of the present invention there is provided a knotter comprising a twine holder, operable to hold, during a knot-tying operation, a primary portion and a secondary portion of twine in which a knot is to be tied, the twine holder including rotary means mounted on a shaft of the twine holder for rotation, a rotary billhook attached at an angle to a shaft for rotation and operable to the tie knot in the primary and secondary portions of twine, and intermittent drive means disposed between the billhook shaft and the twine holder shaft and operable such that the billhook shaft intermittently drives the twine holder shaft during the knot-tying operation.

The rotary means of the twine holder may comprise a plurality of spaced coaxial flanges mounted on the twine holder shaft, the twine holder further comprising at least one substantially stationary twine retainer finger cooperable with two adjacent flanges to hold the primary and secondary portions of twine.

In either aspect of the invention the twine holder flanges may have three or more sides, but are preferably generally triangular in shape, and comprise one notch on each side edge, the notches being arranged to receive the primary and secondary twine portions prior to the latter being caught and held between the flanges and the retainer fingers. Each notch in each flange may be generally V-shaped and located adjacent one corner of the flange such that, when seen in the direction of rotation of the twine holder flanges, the notches lead the associated twine holder flange corners.Preferably, the flanges are axially aligned with each other in a manner such that the notches in adjacent flanges define grooves which extend generally parallel to the twine holder shaft with one of the grooves being offset relative to the plane through the axes of rotation of the twine holder and billhook and being movable towards said plane during operation.

The twine holder may comprise four spaced twine holder flanges and three twine retainer fingers each of the fingers being disposed between one pair of adjacent flanges. Each twine retainer finger may comprise a first section and a second section, the first section being cooperable with the associated twine holder flanges to hold twine up to a predetermined tensile load being exerted on the twine, and the second section being cooperable with the flanges to hold the twine under a higher tensile load on the latter.

The first and second sections of each finger may have arcuate working edges, the working edge of the second section having a radius of curvature which is smaller than the radius of curvature of the working edge of the first section.

An agricultural baler embodying the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a top view illustrating a baler including two knotters according to the invention, Figure 2 is a sectional view taken along the line Il-Il of Figure 1, Figure 3 is a partial view taken along the line Ill-Ill of Figure 2, Figure 4 is a sectional view taken along the line IV--IV of Figure 3, Figure 5 is a view of one knotter taken in the direction of the billhook shaft thereof, Figure 6 is a part sectional view taken along the line VI--VI of Figure 5, Figure 7 shows a frame for each knotter viewed in the same direction as Figure 5, Figure 8 is a sectional view taken along the line VIll-VIll of Figure 7, Figures 9 and 11 show portions of the knotter billhook, Figure 10 is a view taken in the direction of line X-X of Figure 9, Figures 12 and 14 show knotter twine holder components, Figure 1 3 is a sectional view taken along the line XIlI-XIll of Figure 12, Figure 15 is a view taken along the line XV XV of Figure 14, Figure 16, shows a further knotter component indicated at XVI in Figure 5, Figure 1 7 is a side view taken in the direction of arrow XVII of Figure 16, Figure 1 8 is a sectional view taken along the line XVlll-XVIlI of Figure 6, Figure 1 9 shows, to a larger scale, the component indicated at XIX in Figure 1 8, Figure 20 is a view taken in the direction of line XX of Figure 19, Figure 21 shows, to a larger scale, the component indicated at XXI in Figure 18, Figure 22 is a side view taken in the direction of line XXII of Figure 21, Figures 23 and 24 show one knotter billhook in two different positions during the knot tying cycle, Figure 25 is a side view taken along the line XXV-XXV of Figure 24, Figure 26 is a top view of a section of the top wall of the baler chamber in the vicinity of one knotter, Figure 27 is a sectional view taken in the direction of line XXVll-XXVII of Figure 26, and Figure 28 is a diagram illustrating the drive for each knotter.

The agricultural baler, generally designated at 8 in Figure 1, is somewhat typical of that in general use and comprises a wheel supported chassis upon which are mounted a pick-up mechanism 11, a feeder mechanism 12 and a bale chamber 13. As cut crop material is picked up from the ground, it is fed in successive batches or charges into the inlet of the bale chamber 13 and the batches of material are compressed into bales 14 by a reciprocating plunger 1 6 which also advances the bales along the chamber 1 3 towards an outlet 17 in the direction of arrow 1 8.

As can perhaps best be seen in Figure 2, a primary portion or length 20 of twine or other flexible tie material 21 extends across the bale chamber 13 in the path of the leading end 1 5 of each bale 14 from a supply reel or container 22 and passes through the eye of a needle 23 with a primary portion 20 of the twine 21 being held in a knotter 24 mounted on a top wall 9 of the bale chamber 13. The baler carries a pair of identical knotters 24, and each knotter is arranged to cooperate with a needle 23, whereby a pair of needles also has to be provided.

A main drive shaft 30 (Figures 2, 3, 4) is rotatably journalled in supports 31 on the upper wall of the bale chamber 13 at a distance thereabove and transversely of the bale chamber.

The main drive shaft 30 is intermittently actuated by a conventional trip mechanism 32 which includes a starwheel 33 arranged to engage the bale of hay or other material as it is being formed, whereby it is rotated about a shaft 34 as the bale 14 moves along the chamber 13. The shaft 34 is operatively coupled to a trip lever 36 which itself is connected to a clutch mechanism 37 mounted on the main shaft 30. One half of the clutch mechanism 37 is driven continuously through a chain or sprocket drive transmission from an intermediate shaft on the baler, only a sprocket 38 thereof being shown in Figures 2 and 3.

The diameter of the starwheel 33 and the transmission ratio between the shaft 34 and the trip lever 36 are such as to allow the formation of a bale of predetermined length before the trip mechanism actuates the clutch mechanism 37, whereupon the main shaft 30 is driven to initiate the tying of a knot by each knotter 24. The main shaft 30 has a crank arm 39 attached thereto at its end opposite to the clutch mechanism 37, the arm 39 being connected by a pitman or link 40 to a needle frame 41 which carries the pair of needles 23. The needle frame 41 is pivotally mounted on the bale chamber 13 by bearings 42.

The bale chamber 13 has a pair of longitudinal slots in its lower and upper walls to accommodate the needles 23 when pivoted to their full throw positions.

No further elaboration will be given concerning the structural details of the trip mechanism 32 and the needle frame and drive mechanism as these details are sufficiently well known in the art.

Suffice it briefly to summarise the operation thereof. Upon actuation of the clutch mechanism 37, the main shaft 30 is driven, and the needles 23 move from the rest position (indicated by full lines in Figure 2) to their full throw position (shown partially in phantom lines in Figure 2) to wrap the respective twines 21 around the bottom and trailing ends 19 and 25, respectively, of the bale 14 and place the secondary portions 43 of the twines in the respective knotters 24. Each twine 21 loops back over the needle 23 to reel 22 in the full throw position, thereby leaving a new primary portion of length of twine 20 across the path of the next bale to be formed.As each needle 23 returns to its rest position, the ends of each primary and secondary portion 20 and 43 are twisted and tied together by the knotter 24, with the primary and secondary portions 21 and 43 being severed at the end of the tying operation.

The entire knotting or tying operation takes place between successive strokes of the baler plunger 16.

The main shaft also has attached thereto a single conical gear segment 50 having teeth 51 over only about 1/3 of its circumference. The gear teeth 51 are arranged to mesh with the teeth of a conical gear 52 which is mounted on one end of a stub shaft 53 dn the other end of which is mounted a sprocket 54. The shaft 53 is journalled in a support 56. A chain 57 engages the sprocket 54 and sprockets 58 and 59 of the respective knotters 24.

As already stated, the two knotters 24 are identical and, therefore, only one will be described in further detail in relation to the associated needle 23 and other components.

By way of general introduction to the knotter structure, attention is directed to the cross sectional view of Figure 6 in which the basic component parts and their interrelationships can be seen.

Each knotter 24 is mounted on the top wall 9 of the bale case 1 3 adjacent an elongate aperture 10 and in the vicinity of twine guide rollers 61 (Figure 6). The knotter 24 includes a base or support frame 62, a twine holder 63 rotatably mounted by a twine holder shaft 64 on the support frame 62, a billhook 66 including a hollow shaft 99 extending parallel to the twine holder shaft 64 and rotatably supported on the support frame 62 and a Geneva mechanism 67 between the billhook shaft 99 and the twine holder shaft 64.

As clearly seen in Figure 6, the twine holder 63 is maintained at an angle v relative to the top wall of the bale chamber 13. Though further discussion will be given below, it should be appreciated at this time that v is an acute angle and allows for a better placement of the twine in the twine gripping area 1 80 of the twine holder 63 by the needle 23. Also, as can be seen in Figure 6, the billhook 66 is oriented at the same acute angle v relative to the top wall of the bale case and is disposed closely adjacent the underside of the twine holder 63. This parallel relationship between the twine holder 63 and the billhook 66 permits the billhook 66 to be better disposed for the knot tying operation.The following is a more detailed description of the structural configuration of the knotter 24 and the important interrelationships of the parts, particular reference being made to Figures 6 to 11.

The support frame 62 includes a generally horizontal bottom plate 70 (Figures 5 and 6) which is adapted to be removably affixed to the top wall 9 of the bale chamber 13. An upright member 71 is welded or otherwise secured to the bottom plate 70 and carries twin cylindrical bearing sleeves 72 and 73, respectively, the one disposed generally vertically above the other and both extending parallel to each other and in a generally fore-and-aft direction although inclined at an angle of about 30 to 35 degrees to the bale chamber top wall 9, with the rear end of the twin bearing sleeves 72, 73 being positioned at a high level above the chamber top wall 9 than the forward end. The twin bearing sleeves 72, 73 comprise forward and rearward sections 44;45 and 68;69, respectively, spaced from each other and defining therebetween a free space 46.A coupling piece 47 connects the forward and rearward sections 44, 45 and 68, 69 of the twin bearing sleeves 72, 73 at a location offset to the right of the sleeves as seen in the fore-and-aft direction of the baler. Bushings are pressed in the bearing sleeve sections 44, 45; 68 and 69.

A further support member 28 is provided at a distance to the left of the forward section 44 of the twin bearing sleeve and is coupled to said forward section 44 by a coupling member 29.

Each knotter comprises an actual knotter mechanism or billhook, indicated generally at 66, with which is associated a hollow billhook or twister shaft 99 rotatably journalled in the sleeve sections 44, 45 of the lower bearing sleeve 72.

The twister shaft 99 supports at one end the associated driving sprocket 58 or 59. The billhook 66 comprises a fixed jaw 75 inclined at about 90 degrees to the end of the twister shaft 99 opposite to the sprocket 58 or 59 and adjacent, on the one hand, the aperture 10 in the top wall 9 of the bale chamber 13 and, on the other hand, a twine holder of the knotter which is generally indicated at 63. In the rest position, the billhook 66 projects downwardly towards and partially through the aperture 10 in the top wall 9 of the bale chamber 13 (as can be seen in Figure 6). The fixed jaw 75 has an elongated body which is wider than it is thick or deep and has a bent tip portion 76 which, in the rest position, extends transversely of the bale chamber 13. The fixed jaw 75 has a length which is in the range of 5 to 6 cms.At the side facing the twister shaft 99, the fixed jaw 75 comprises an elongated groove or recess 77 for receiving a crochet hook 65 of a movable jaw 78 of the billhook 66. At the junction of the fixed jaw 75 and the twister shaft 99, the fixed jaw 75 is provided with an elongated slot 79 through which the movable jaw 78 extends and in which it is pivotally mounted by a pivot pin 80.

The movable jaw 78 has at one end a heel portion 81 which acts as a cam follower with respect to a roller cam 82 (Figures 5 and 6) as the twister shaft is rotated. The roller cam 82 comprises a part-spherical surface and is freely rotatably mounted on the knotter frame 62 at the lower and forward end of the front sleeve section 44 by means of a stub shaft 83.

The movable jaw 78 further omprises a recess for notch 84 in the side opposite to the fixed jaw 75 at a location slightly offset relative to the pivot 80. A mechanism for spring loading the movable jaw 78 is provided inside the hollow twister shaft 99 whereby the jaw is urged to the closed position. Referring to Figure 6, this mechanism comprises a spring 85 inserted in the hollow shaft 99 and abutting at one end against the end of the bore and at the other end against an abutment member 96. The abutment member 86 has an angled end adapted for engagement with the notch or recess 84 in the movable jaw.

It will be noted that the fixed jaw 75 has smooth, rounded surfaces at 55 and at the connection between the billhook and the twister shaft. The movable jaw 78 has rounded edges as well as the heel portion 81 thereof, and at the opposite lip portion 35 as indicated in Figure 11.

The twister shaft 99 carries intermediate the sleeve sections 44, 45 of the twister shaft bearing sleeve 72 one half of the Geneva drive mechanism 67 which is intended for driving the twine holder 63. This Geneva drive mechanism will be described in more detail hereinafter.

The twister holder 63 itself comprises four generally triangularly shaped flanges or discs 90, 91,92 and 93 which are spaced from each other by respective spacers 94, 95 and 96 which define, with the flanges, respective slots or grooves 87, 88 and 89 of varying depth. The flanges or discs 90, 91 92 and 93 are of the same size which, in comparison with known twine discs, are relatively small. Indeed, the flanges 90 to 93 have side edges measuring in the range of 4 to 5 cms. only. The flanges have slightly rounded corners at 98 and comprise, adjacent said corners, V-shaped recesses or notches 100 as best seen in Figure 12. One V-shaped recess 100 is provided adjacent each corner in the side of the triangular shape which, as seen in the direction of rotation 101 of the twine holder 63, leads the associated corner 98. The recesses 100 have a smaller depth than the grooves 87, 88 and 89 between the adjacent flanges 90, 91, 92 and 93 at the location where the recesses 100 are provided. The V-shaped recesses 100 have their open ends facing more or less in the direction of rotation 101. All edges of the recesses 100 are rounded to avoid inadvertznt twine cutting or damage to the twine as, in use, twine is caused to slide therealong.

The flanges or discs 90, 91, 92 and 93 together with the spacers 94, 95 and 96 are welded or otherwise secured to the twine holder shaft 64 in a manner so that they extend parallel to each other with the corners 98 and recesses 100 aligned with each other in the direction of the twine holder shaft 64. Thus the recesses 100 in the adjacent flanges 90 to 93 define three grooves 102,103 and 104 (Figure 12) which are oriented parallel to the twine holder shaft. The twine holder flanges 90 to 93 are positioned forwardly of the front face of the section 68 of the twine holder bearing sleeve 73, on the one hand, and rearwardly of the plane of rotation of the billhook 66, on the other hand.To this end, the forward section 44 of the billhook shaft bearing sleeve 72 is made substantially longer than the forward section 68 of the twine holder shaft bearing sleeve 73, thus providing a free space 105 (Figure 8) above a portion of the billhook bearing sleeve section 44.

The fixed jaw 75 of the billhook 66 is dimensioned and positioned relative to the twine holder flanges 90 to 93 so that upon rotation, the fixed jaw 75 moves in front of the twine holder 63 whereby, as seen in the direction of the bill hook shaft 99, the plane described by the bill hook 66 substantially overlaps the twine holder 63.

A knife arm 106 (Figures 5 and 17) for the twine holder 63 is bolted at 107 to the further support member 28 of the frame 62 and extends upwardly and sidewardly from its fixation point 107 to a location in front of the centre of the twine holder 63, at which location a mounting pin 1 08 is provided which extends coaxially with the twine holder shaft 64 and which fits in a bore 109 (Figures 12, 13) therein. This pin 108 thus together with the bolt 107 helps holding the knife arm 106 in position.

The knife arm 106 is further extended to the right beyond the centre of the twine holder 63 to form at this location a first stationary twine guide 110 in front of the twine holder 63. The first stationary twine guide 110 is positioned so that the tip of the bill hook 66 can pass in front thereof during rotation and comprises forward rounded edges as can be best seen in Figures 1 6 and 17.

A further support member 111 (Figure 17) projects forwardly from the knife arm 106 ata location adjacent the fixation point 107 and carries adjacent its free end a second stationary transverse twine guide 11 2. This second twine guide 11 2 is positioned slightly lower than the first twine guide 110 and also further to the front to the extent that, during operation, the bill hook 66 passes between the first and second twine guides 110 and 112. This second twine guide 112 has a downwardly inclined free end 11 3 which is positioned inwardly of the turning circle of the tip 76 of the billhook 66 (when seen in the direction of the billhook shaft 99). The second twine guide 112 preferably is formed from a rod of circular section.

Attached to the first twine guide 110 and in shearing contact with the underside of the lower twine holder flange 90 is a stationary knife 114 having a cutting edge 11 5 which is inclined at a positive angle relative to a radius of the flange 90 which passes through that edge, when seen in the direction of rotation 101 of the twine holder. This means that twine being cut tends to move radially outwardly of the flange 90.

Twine retainer fingers 11 6, 117 and 118 (Figures 5 and 15), which are integrally connected at one end by a mounting member 119, are pivotally mounted via the member 11 9 at 120 to the further support member 28 of the frame 62.

The mounting member 119 and the twine retainer fingers 116,117 and 118 extend from the pivot 120 in a transverse direction across the twine holder 63 and extend in part into the grooves 87, 88 and 89, respectively. The transverse mounting member 11 9 and the fingers 116 and 11 7 have an inclined edge 121 opposite the pivot, which edge acts as a twine guide, assisting in the positioning of the secondary portion 43 of the twine in the groove 102 as seen in Figure 5. The edge 121 partly defines a generally hooked end 1 22 of each finger 11 6 and 117 which, at least in the lower finger 116, has a straight edge 123 (Figure 14) which also acts as a twine guide.The edges of the fingers 116, 11 7 and 11 8 facing towards the twine holder 63 and extending between the flanges thereof each comprise a straight section 124 and a curved section 125, separated by a curved section 126 of a smaller radius than the section 125 (Figure 14). The fingers 11 6, 11 7, and 118 are resiliently urged into grooves 87, 88 and 89 by a leaf spring 1 27 (Figure 5) which also is pivotally mounted on the pivot 120 and which extends in the direction of the fingers 116, 11 7 and 118 and contacts the mounting member 119 at 128. A spacer 129 is provided between the mounting member 11 9 and the leaf spring 127, being disposed coaxially with the pivot 120.An adjustable, screw 130 mounted on the further support member 28 between the pivot 120 and the contact point 128 provides adjustment of the force exerted by the spring 127 on the twine fingers 116,1 17 and 118.

A third and fourth stationary guide member 131 and 132, respectively, (Figures 5 and 6) are integrally coupled to each other by a connecting piece 133 which is attached to the coupling piece 47 of the frame 62. The third stationary guide member 131 has a curved guiding edge 134 extending generally in a plane parallel to, and closely adjacent, the front edge of the lower twine holder flange 90. Together with the inclined edge 121 on the twine fingers 116 and 117, the guide edge 134 defines a generally V-shaped (when seen in the direction of the bilihook shaft) having its apex generally at the groove 102 in the twine holder 63. This guiding edge 1 34 and the inclined edge 121 cooperate to direct twine inwardly towards the twine gripping area 1 80 defined by the groove 102 and the twine fingers 11 6 and 117.

A set of spaced apart twine disc cleaners 135 (three in total, so that one cleaner is provided in each of the grooves 87, 88 and 89) of a generally spiral shape and extending from the connecting piece 133 gradually into the grooves 87, 88 and 89 have their free ends engaging the spacers 94, 95, 96 in these grooves so as to remove any material therein and direct it away from the knotter.

The fourth stationary guide member 1 32 also has a curved guide edge 136 which is disposed in a plane in the vicinity of the front face of the rearward section 69 of the bearing sleeve 73 and which leads to the free space 46 between the front and rear sections 68, 69 of the bearing sleeve 73.

All twine guide edges of the stationary twine guides 110, 112, 131 and 132, the twine holder flanges 90, 91, 92 and 93 and the twine fingers 116, 117 and 118 which are contacted by the baling twine are rounded so as to avoid twine damage and inadvertent twine cutting.

The Geneva drive mechanism 67 disposed in the free space 46 and drivingly coupling the billhook shaft 99 to the twine holder shaft 64 will now be described in greater detail with particular reference to Figures 1 8 to 22. Such type of drive mechanism is however, generally known in the art of intermittent drive mechanisms.

On the billhook shaft 99 there is keyed a driving component 140 comprising basically a cylindrical body 141 which is part of a lock mechanism 142, and an eccentric driver cam 143 secured thereto. The eccentric driver cam 143 faces in the direction of the billhook 66 and is spaced from the cylindrical body 141 by a spacer body 144 with rounded edges 145 at the side of the driver cam and of a slightly smaller diameter than the cylindrical body 141. At a location forwardly of the driver cam 143, when seen in the direction of rotation 146 of the billhook shaft 99, a section of the cylindrical body 141 and of the spacer body 144 has been cut away (at 147) for a reason which will become clear. The driver cam 143 has a rounded driving surface 148 suitable for driving engagement with a driven part 150 on the twine holder shaft 64.

The driven part 1 50 of the Geneva drive mechanism 67, which is keyed on the twine holder shaft 64, basically comprises two starwheel components spaced apart by a spacer body 151 of reduced diameter The front starwheel component 1 52 is adapted to be drivingly engaged at intervals by the driver cam 143 and comprises, to this end, six equally angularly spaced legs 153 having convex sides 155 engageable by the convex driving surface 148 of said driver cam 143. The sides 154 opposite to the convex sides 155 have a concave shape. Between the legs 153, pockets 1 58a to 158fare formed.The side edges 1 56 of the legs 1 53 facing away from the twine holder 63 are rounded to avoid inadvertent twine cutting and twine damage as baler twine slides therealong (Figures 19, 20). Indeed, and as will be explained in more detail herinafter, the starwheel component 152 not only acts as a drive transmission component, but also acts as a twine guide.

The rear starwheel member 160, which is part of the lock mechanism 142, is differently shaped and comprises six concave sides 161 which are shaped and dimensioned so that each of these sides may engage the cylindrical body 141 on the billhook shaft 99 whereby rotation of the twine holder shaft 64 is made impossible. Thus, in other words, when any of the concave sides 161 engages the cylindrical body 141, the twine holder flanges 90 to 93 are firmly locked and can only be rotated after the billhook 66 and the cylindrical body 141 on the billhookshaft 99 have been rotated to the extent that the release surface 147 of the locking member 141 faces the starwheel member 160, as in this position, the points of the starwheel member 1 60 are free to move beyond said surface.

As seen in Figure 19, the rear starwheel member 1 60 is slightly angularly offset with respect to the front starwheel member 1 52. It will be clear from what precedes that rotation of the driver cam 143 in the direction 146 will cause rotation of the twine holder shaft 64 in the opposite direction 101.

Finally, a fifth stationary guide member 1 65 is attached to the rearward section 69 of the bearing sleeve 73 and extends in a direction generally parallel to the twine holder shaft 64 into the vicinity of the rear side 1 56 of the front starwheel member 152, thus overlying the rear starwheel member 160 and the spacer body 1 51.

At its forward edge, this guide member 165 is arcuate in shape and has a width, and is positioned, so that said forward edge extends from behind the top leg 1 53 (when the knotter is in its rest position) of the forward starwheel 1 52 to a location behind'the next preceding leg 153 of the same.

A straw deflector 1 70 is provided on the inner side of the bale chamber topwall 9 in the vicinity of each knotter 24 and at the section of the elongate aperture 10 rearwardly of the point where the associated needle 23 is intended to project through. The deflector 170 comprises generally elongate and vertical wall sections 1 71 provided at opposite sides of the elongate aperture 10 and extending a predetermined depth into the bale case. One of these vertical wall sections 1 71 rotatably carries the twine guide roller 61 mentioned previously.A generally horizontal wall section 1 72 is attached to the lower edge of the vertical wall section 171 carrying the roller 61 and extends to the vicinity of the other vertical wall section 1 71, leaving only an elongate aperture 1 73 of reduced width therebetween. This horizontal wall section 1 72 thus shields the twine guide roller 61 from the bale chamber and prevents baled crop material from fouling that roller.

The horizontal wall section 1 72 has a tapered and upwardly curved leading end 1 74 which is positioned slightly rearwardly of the location in the aperture 10 where the needle 23 is intended to project through. The edge 175 of this tapered end portion 174 acts as a stationary twine guide, leading twine into the space defined by the vertical and horizontal wall sections 171 and 172 in a manner to be described. This leading edge 1 75, together with the edges of the wall sections 1 71 and 1 72 defining the elongate aperture, has been rounded to avoid twine damage and twine cutting when twine is caused to slide therealong.

Upon rotation of the main shaft 30, the needles 23 move from their rest position to their full throw position during the first 1 80 degrees of rotation of the main shaft. During the next 1 80 degrees the needles are fully retracted. The conical gear segment 50 on the main shaft 30 is dimensioned and positioned so that during the first 120 and the last 120 degrees of rotation of the main shaft 30, the knotters 24 are not actuated. The knotters are driven only during the second 120 degrees of rotation of the main shaft 30, that is from the moment the needles 23 have reached the vicinity of the knotters over their full stroke position to the point where they move away from the vicinity of the knotters. Figure 28 schematically shows the cycle of 360 degrees of the main shaft 30.At 181, the needles 23 are in the rest position and at 183, the needles 23 are in the full throw position.

At 1 82 the knotter drive is started while at 1 84 said drive is already terminated.

The transmission ratio between the main shaft 30 and the billhook shafts 99 is such that during the second 120 degrees of rotation of the main shaft 30, the bill hooks 66 make two complete revolutions or thus rotate through 720 degrees.

Finally, the Geneva mechanism 67 of each knotter 24 is arranged so that each billhook shaft 99 drives the twine holder shaft 64 over 60 degrees during the last quarter of each full revolution of the billhook. Thus, during one complete knotting cycle, the twine holder 63 is rotated twice through 60 degrees, i.e. in total through 120 degrees. This intermittent rotation of the twine holder 63 is thus obtained during the last 1 5 degrees of rotation of the main shaft 30 before the needles 23 reach their maximum stroke position and during the last 1 5 degrees of rotation of the main shaft 30 before the drive to the billhook 66 is interrupted.

During operation, the baler is moved across a field and crop material, such as hay to be baled is picked up from the ground with the pick-up mechanism 11 and is delivered thereby to the feeder mechanism 1 2 which in turn feeds the crop material in successive batches or charges into the bale chamber 13 in timed sequence with the reciprocating baler plunger 1 6. The plunger 16 compresses the crop material into a bale 14 and at the same time gradually advances the bale towards the outlet 1 7 of the baling chamber in the direction of arrow 1 8. As material is compressed in the bale chamber, the deflector members 1 70 form grooves in the bale 14 being formed for placement of the twine therein.The horizontal wall section 1 72 and the curved leading end 1 74 prevent crop material fouling the twine guide roller 61 and the billhook 66 as well as shifting the primary portion 20 of twine 21 in the one or other direction.

As long as the clutch mechanism 37 is not actuated, all components of each knotter 24 are in their rest positions. This means that the needles 23 are in their lowermost dwell position, as shown in full lines in Figure 2, while the billhooks 66 project downwardly as seen in Figures 2, 5, 6 and 1 8. As already mentioned a primary portion 20 of twine 21 extends across the bale chamber 13 in the path of the leading end 1 5 of the bale 14 being formed and passes through the eye of a needle 23, with the free end of the primary portion being supported in the twine holder 63 of the associated knotter 24, bearing in mind that two knotters are employed, whereby each bale 1 4 is bound by two pieces of twine.The free end of the primary portion 20 of the twine 21 is received in the groove 103 of the twine holder 63 at which point it is firmly held in position by the twine retainer fingers 116,117 and 118 between the curved sections 1 26 thereof with the smaller radius and the twine holder flanges 90 to 93.

From the groove 103 the primary twine portion 20 extends away from the billhook 66 through the pocket 158c, around and behind the legs 1 53b and 1 53a and through the pocket 1 58a of the forward starwheel member 1 52. As such, it is clear that the primary twine portion 20 extends below the fifth stationary twine guide 1 65. From there, the primary twine portion 20 extends downwardly in a forward direction into the next groove 102 of the twine holder 63, down across the first and second stationary twine guides 110 and 11 2 respectively, and finally down and around the twine guide roller 61 into the bale chamber 1 3. This free end of the primary portion 20 of the twine 21 is tensioned and thus forcefully bears against all the components listed above, whereby it is properly positioned relative to the billhook 66.

As a bale 14 is being formed and moved along the bale chamber 13, the starwheel 33 is rotated thereby and as the bale reaches a predetermined length, the wheel 33 actuates the clutch mechanism 37, whereupon the main shaft 30 is rotated through 360 degrees by the chain and sprocket drive mechanism. During the first 1 80 degrees of rotation of the shaft 30, the crank arm 39, the pitman arm 40 and the needle frame 41 are pivoted whereby the needles 23 move from their lowermost rest positions to their highest, full throw, positions (phantom lines in Figure 2) along a path closely adjacent the first and second stationary guide members 110 and 11 2, through the twine gripping area 1 80 defined in part by the guide edge 134 of the third guide member 131, on the one hand, and the inclined surface 121, on the other hand, and substantially parallel to the twine holder shaft 64.

Simultaneously, as is known in the art, the baler plunger 1 6 is moving towards its extreme material compressing position and, as the needles 23 move upwardly through the bale chamber 13, they pass through slots (not shown) in the face of the plunger 16, whereby the plunger holds the crop material to be baled, away from the needles 23 and thus provides a smooth and unobstructed passage for the needles 23 through the bale chamber 13 and prevents bending and/or breakage of the needles 23.

During the next 1 80 degrees of rotation of the main shaft 30, the needles 23 are retracted and returned to their rest or dwell positions. At the same time, the plunger 1 6 is retracted. During the initial movement over 120 degrees of the main shaft 30, the teeth 51 of the gear segment 50 are not in mesh with the teeth of the conical gear 52, whereby neither knotter 24 is operated.

During the initial movement of the shaft 30, each needle 23 carries the end of the secondary twine portion 43 from the position shown in full lines in Figure 2 around the bottom and trailing ends 19 and 25 of the bale 14 to the position shown in phantom lines in Figure 2. At that moment, the needle 23 places the secondary twine portion 43 alongside the related primary twine portion 20 against the first and second stationary guide members 110 and 112 and in the groove 102 in the twine holder 63 and in the pocket 1 58a of the starwheel member 152. The third stationary twine guide 1 31, together with the inclined edge 121, helps to locate the secondary twine portion 43 in the twine gripping area 1 80 of the twine holder 63 and finally the groove 102.The fourth stationary guide member 132 helps in leading the secondary twine portion 43 into the pocket 1 58a. At this point in the cycle, the groove 102 and the pocket 1 58a are positioned transversely offset to the right relative to the plane through the billhook 66 and twine holder shaft 64, when seen in the fore-and-aft direction of the baler.

As the bale 14 being formed moves along the bale chamber 13, the secondary twine portion 43 (and also the primary portion 20 for the next bale) is caused to move along the curved leading end 174 of the horizontal wall section 1 72 in the bale chamber, whereby ultimately the secondary twine portion 43 is located within the elongate aperture 173. The primary twine portion 20 of the next bale ultimately is located in the same manner through the aperture 1 73 and still later, the primary twine portion starts bearing against the twine guide roller 61 as the bale is moved along the bale chamber 13 to the outlet 1 7.

At the point 1 82 (Figure 28) in the cycle of the main shaft 30, the gear segment 50 meshes with the conical gear 52 whereby the billhook 66 starts rotating. The billhook 66 completes a full cycle of 360 degrees as the main shaft 30 reaches the position 1 83. During the first 3/4 of the billhook cycle, that is until the main shaft 30 reaches the position 185, the twine holder 63 remains unactuated. During the first half of the first cycle of the billhook 66 (main shaft 30 moving from the position 182 to position 187), the billhook is moved to a position in which it projects between the first and second stationary guides 110 and 112. At this point, the heel 81 of the movable jaw 78 engages the roller cam 82, whereby the billhook 66 is opened against the spring load of the coil spring 85 in the hollow twister shaft 99.However, at this point in the first cycle of the billhook no strands of twine are presented in a manner to be caught between the fixed and movable jaws 75 and 78, respectively, and thus opening of the billhook 66 is without effect.

During the third quarter of the first billhook cycle, that is when the main shaft 30 moves from position 1 87 to 1 85, the path of the billhook 66 intersects both twine portions 20 and 43 which, at this point in the cycle, forcefully bear against the first and second twine guides 110 and 11 2, whereby said portions are brought together unless they are already in this relative position.

Also during this third quarter of the first billhook cycle the billhook 66 is closed again.

Simultaneously, the billhook 66 pushes both twine portions 20 and 43 to the right to the extent that they jump off the bent end 113 of the second twine guide 112. The bent tip portion 76 of the fixed billhook jaw 75 ensures that both twine portions are positively caught and that neither escapes from the grip of the billhook 66.

As the twine portions 20, 43 jump off the bent end 113 of the second twine guide 112, they then project from the first twine guide 110, against the leading edge 74 and in the path of the fixed jaw 75, directly to the twine guide roller 61.

The twine portion 20, 43 are thus brought closer to the forward end of the knotter mechanism.

During the fourth quarter of the binhook cycle, that is when the main shaft 30 is moved from position 185 to position 183, the billhook 66 starts looping the twine portions 20 and 43 around its fixed and movable jaws 75 and 78, on the one hand, and the twine holder 63 is rotated over 60 degrees in the direction 101, on the other hand. In order to form this loop, additional twine length is required and this is obtained after the twine holder has completed the first 60 degrees rotation, in a manner to be described.

As far as the loop formation is concerned, continued rotation of the billhook 66 from its 270 degrees position to its 360 degrees position causes both twine portions 20, 43 to slide along the billhook components in a manner such that, as the billhook reaches its 360 degrees position, the twine portions extend from within the bale chamber 13 (twine portion 20 bears against the twine guide roller 61 and twine portion 43 bears against the rear end 25 of the bale 14 just formed), across the leading edge 74 ofthe fixed jaw 75, behind the movable jaw 78 and against the forward end of the twister shaft 99 at the right hand,side thereof (as seen in the fore-and-aft direction of the machine) to the first stationary guide 11 0. This situation is shown in Figure 23.

As mentioned above, during the fourth quarter of the bilihook cycle, the twine holder 63 is rotated over 60 degrees, as a result of which the primary and secondary twine portions 20, 43 positioned in the groove 102 of the twine holder are caused to move in the same direction and towards the twine retainer fingers 116, 11 7 and 11 8. The guide edges 123 on the twine retainer fingers 116,117 117and 118 wedge the twine portions between the fingers and the associated flanges 90, 91, 92 and 93. As the twine holder 63 approaches its intermediate position (after 60 degrees rotation) the twine portions 20, 43 are firmly caught and held between the low force arcuate sections 1 25 of the twine retainer fingers and the flanges and can only slide therebetween under a substantial tensile load.

Actual sliding of the primary twine portion 20 is possible only after the end thereof which previously was firmly held between the high pressure arcuate sections 126 of the twine retainer fingers 116,117 and 11 8 and the flanges 90, 91, 92 and 93 is released. However, this is accomplished shortly after both twine portions 20, 43 get caught between the low force sections 125 of the fingers 116, 117and 118 and the flanges 90, 91, 92 and 93, as at that moment the end of the primary portion is moved in the direction of the straight section 124 of the twine retainer fingers.Thus, as the loop formation around the billhook requires additional twine length, the primary and secondary twine portions 20 and 43 are caused to slide through the twine holder 63 as the billhook 66 exerts a substantial tensile load thereon. This condition is maintained until the twine holder 63 is rotated over a further 60 degrees which does not occur until the last quarter of the second billhook revolution. In other words, the further twine holder rotation only occurs when the main shaft 30 is rotated from the position 1 86 to the position 1 84.

As the primary twine porticn is looped around the legs 1 53a and 1 53b of the forward starwheel 1 52 of the Geneva drive mechanism 67 which, as can be seen from the drawings is provided at a distance from the twine holder 63, a substantial twine length is available. As the second twine portion 43 is not yet cut at this point in the cycle, sufficient twine length for the secondary twine portion 43 is also available.

As the twine holder 63 is rotated in the direction 101,the leg 153 of the forward starwheel member 1 52 of the Geneva drive mechanism 67 makes the same angular displacement thus taking with it the secondary twine portion 43 which at that time in the cycle is located in the pocket 1 58a. After the 60 degrees cycle of the starwheel 1 52 is completed, the leg 1 53f is positioned in front of the fifth twine guide 1 65 (position 1 53a in Figure 18), whereby the secondary twine portion 43 is thus trapped in the pocket 1 58a and below the guide 165.

Furthermore, as the twine holder 63 completes its first 60 degree cycle, both the primary and secondary twine portions 20, 43 are caused to slide transversely along the first twine guide 110 in the direction of the bill hook 66, whereby, at the end of the cycle the twine portions are positioned against the heel portion 81 of the movable jaw 78 at the right-hand side thereof in the position shown in Figure 23. This facilitates the completion of the loop formation during the next 1 80 degrees of rotation of the billhook 66 and as will be described.

The Geneva drive mechanism 67 will now be described in further detail. Figure 1 8 shows this mechanism in its rest position, i.e. the position taken when the main shaft 30 is at the position 182 (Figure 28). It will be noted that in this position, one of the concave sides 1 61 of the second starwheel member 1 60 of the lock mechanism 142 is positioned closely adjacent the cylindrical body 141, whereby the lock mechanism 142 is rendered operative and the twine holder shaft 64 is positively prevented from being angularly displaced, even when the twine portions 20, 43 exert a substantial turning torque thereon. It will be noted, however, that rotation of the billhook 66 in the direction 146 remains possible.

As the billhook 66 is rotated from its 0 degree position to its 270 degrees position, the cylindrical body 141 of the lock mechanism 142 remains operative and the driver cam 143 remains inoperative.- During the last quarter of the billhook cycle, the cut away section 147 of the lock mechanism cylindrical body 141 is presented to the second starwheel member 160, whereby the lock mechanism 1 42 is unlatched, thus permitting the twine holder shaft 64 to rotate.

Also during this fourth quarter of the billhook cycle, the eccentric driver cam 143 enters the pocket 158dand engages the leg 153dof the forward starwheel member 1 52 thus causing the latter to rotate over 60 degrees in the direction 101. Thereafter the lock mechanism 142 assumes again a locked position, whereby rotation of the twine holder is again prevented.

At the end of the first cycle of the billhook 66 each needle 23 has reached its full throw position and is at the point of returning to its fully retracted or dwell position. The needles 23 reach their dwell positions when the main shaft 30 returns to its position 1 81. During this movement, each needle 23 carries a further portion of twine 43 down the trailing end 25 of the formed bale 14 and this twine portion becomes primary twine portion for the next bale to be formed.

When the main shaft 30 has reached the position 184, the gear segment 51 passes beyond the conical gear 52, whereby drive to the knotters 24 is interrupted. Thus, further rotation of the main shaft 30 from the position 1 84 to the position 1 81 merely completes the retraction of the needles 23 to their dwell positions.

As the main shaft 30 moves from the position 1 83 to the position 186, the twister shaft 99 is rotated over 3/4 of the second revolution of 360 degrees. During this portion of the cycle, the twine holder 63 remains unactuated. As the main shaft 30 moves from the position 186 to the position 184, the twister shaft 99 completes the last revolution of the knotter cycle and the twine holder shaft 64 is rotated over a further 60 degrees. Thereafter the knotter components are positioned so that a further knotting cycle can be initiated as the next bale in the bale chamber is completed.

As the main shaft 30 moves from the position 1 83 to the position 188, the twister shaft 99 is rotated over the first 1 80 degrees of its second revolution. During the first 90 degrees, the lower parts of the twine portions 20, 43 begin to slide over the leading edge 74 of the bill hook 66 towards the base thereof. Simultaneously, the heel portion 81 of the movable jaw 78 hooks behind the upper parts of the twine portions 20 and 43 thus causing them to slide in the direction of the base of the billhook over the curved section 97 of the movable jaw 78. Continued rotation of the billhook shaft 99 towards 1 80 degrees position results in a loop being completed around the billhook 66.

As this loop is being completed, the heel portion 81 of the movable jaw 78 contacts the roller cam 82 for the second time which opens the jaws 75 and 78 and the twine portions 20 and 43 are now in a position relative to the billhook 66 in which they can enter the open jaws as seen in Figure 24. This is because the twine portions 20 and 43 no longer bear against the second stationary twine guide 11 2 but instead only bear against the first stationary twine guide 110.

As the heel portion 81 moves off the roller cam 82 during movement of the twister shaft 99 from the 1 80 degrees position to the 270 degrees position, the jaw 78 is closed due to the action of the spring 85, whereupon the twine portions 20 and 43 are firmly clamped between the billhook jaws 75 and 78.

During the loop-forming part of the cycle, a substantial tensile force is exerted on the twine portions 20 and 43 causing them gradually to slip a limited amount between the flanges 90, 91,92 and 93 and the associated twine retaining fingers 11 6, 11 7 and 118. This is possible, as at this point in the cycle, the twine portions 20 and 43 are held at the low force sections 125 of the twine fingers 116, 117 and 118. This slipping is necessary in order to provide a certain additional twine length with which to form the knot, the appropriate length being determined by the curvature of the surface 97 of the movable jaw 78 and being sufficient not only to enable the knot to be tied but also for the knot to be loose enough (but not too loose) for it to be pulled from the billhook 66.

During the movement of the main shaft 30 from the position 188 to the position 184, the billhook 66 is rotated from its 180 degrees position to its 360 degrees position of the second revolution during which movement the loop of twine slides towards the tip of the billhook 66 with the ends of the twine portions 20 and 43 still clamped between the jaws 75 and 78.

As the main shaft 30 moves from the position 1 86 to the position 184, that is as the billhook shaft 99 completes the fourth quarter of its second revolution, the driver cam 143 of the Geneva drive mechanism 67 engages the leg 153c of the forward starwheel member 152 and simultaneously the cut away section 147 of the cylindrical body 141 of the lock mechanism 142 is again moved in the vicinity of the rear starwheel member 160, whereby the billhook shaft 99 causes the twine holder shaft 64 to rotate over another 60 degrees in the direction 101. As a result thereof a number of functions are accomplished simultaneously.First, the twine portions 20 and 43 in the groove 102 of the twine holder 63 are moved further in the direction 101 to the high force arcuate sections 126 of the retainer fingers 11 6, 11 7 and 118 so that, as already explained, the grasp on the twine portions is increased substantially to the extent that the ends are no longer allowed to slide between the various components, even under an increased tensile load.

As the twine holder 63 moves on to its next following rest position (which is reached when the groove 102 assumes the position of groove 103 in Figure 5), the groove 102 holding the twine portions 20 and 43 moves past the fixed knife blade 114, whereby both portions of twine are severed, leaving the formed bale independent as such although the looped ends of the twine portions are still retained on the biilhook 66. The cutting of the primary twine portion 20 gives rise to a short piece of waste twine and if it does not fall from between the flanges 90, 91, 92 and 93 during the formation of subsequent bales, the twine disc cleaners 135 will remove it.A clean cut of the twine portions 20 and 43 is obtained as at the moment of cutting, these portions are firmly held in the twine holder 63 by the finger sections 126 as described above, on the one hand, and as the pull on the twine portions is increased due to the downward pivotal movement of the billhook 66, on the other hand.

The billhook 66 thus moves to its rest position in timed sequence with the tail ends of the twine portions 20 and 43 being cut. In this position, the jaws 75 and 78 extend generally downwardly and rearwardly towards and partially through the aperture 10 in the bale chamber top wall 9. At this point in the tying cycle, the billhook 66 assumes an angle v to the horizontal which is in the range to 50 to 60 degrees. As stated, the loop just formed is still retained in the billhook 66 with the severed tail ends still clamped between the jaws 75 and 78.

The subsequent strokes of the bale plunger 1 6 cause the wrapped bale 14 to mover further rearwardly along the bale chamber 13, thereby also causing the loop to be pulled off the billhook 66 over the severed tail ends of the twine portions 20 and 43 and to tighten the loop around the tail ends. At this moment, the knot is actually completed. The tail ends of the twine portions 20 and 43 are finally released under the increasing tensile load exerted thereon by the rearward movement of the bale in the bale chamber 13.

Depending on the shape, dimensions and adjustments of the billhook 66, as is generally known in the art, the knot so formed will be an overhand knot or a bow knot.

During the second 60 degrees rotation of the twine holder shaft 64, the forward starwheel member 1 52 and the twine holder flanges 90 to 93 are rotated in unison therewith, so that, as this rotation is completed, the leg 1 53 of the starwheel member 1 52 assumes the position of the leg 1 53b, and the pocket 158a, with the secondary twine portion 43 received therein prior to the first 60 degrees cycle of the twine holder shaft 64, assumes the position of the pocket 1 58c as shown in Figure 1 8. Thus the secondary twine portion 43 is trapped underneath the fifth twine guide 165 and is held thereby behind the face 1 56 of the starwheel member 152.This strand of twine becomes the primary twine portion 20 of the next bale to be formed amd thus sufficient twine length is provided in the knotter for the following knot to be formed therein by looping the twine strand around the legs of the starwheel member 1 52.

As the needle 23 is further retracted, the pocket 1 58e in the starwheel member 1 52 and the groove 104 in the twine holder 63 are brought in position for receiving the primary twine portion 20 for the next bale. The twine portion looping back over the needle 23 is then placed in pocket 1 58e and in the groove 104 and again, the fourth and fifth guides 1 32, 1 65 help in leading the twine portion to the pocket 158e, and the third guide 131 and the inclined surface 121 help in locating the twine portion in the twine gripping area 180 of the twine holder 63.As the needle 23 further retracts, the twine portion is also placed against the first and second guides 110 and 112 from which it extends down into the bale case in front of the leading end 1 5 of a newly formed bale 14, and down through the eye of the needle 23 and then to the reel 22. This twine portion at this point in the cycle is firmly clamped in groove 102 between the flanges 90 and 93 of the twine holder 63 and the high force sections 126 of the twine fingers 11 6, 11 7 and 118, so that, as already explained, the twine cannot slip through said components. As the new bale is being formed, the twine portion is caused to slide along the curved leading end 1 74 of the deflector member 170 in the bale chamber 13, whereby it will enter the elongate aperture and ultimateJy forcefully bear against the guide roller 61.

In typical prior art knotters a twine finger is required to place the twine in the correct position to engage the billhook and a stripping finger or the like is required to strip the loop of twine off the billhook jaws. With the present arrangement, however, the twine finger and twine stripper and drive means therefore are not necessary due to the particular arrangement of the twine holder relative to the billhook, due to the provision of one or more stationary twine guides disposed in the vicinity of the path of the bilihook, and due to the fact that the billhook has a twine "assembling" and positioning cycle (more precisely the second half of the first billhook revolution) in addition to a knotting cycle.Furthermore, the normal movable knife blade for cutting the twine after a knot has been tied, has been replaced by a simple stationary knife with the relative movement required for the cutting operation being provided by the rotation of the twine holder. This further simplifies the structure.

Because of the small dimensions of the twine holder, because of the orientation of the twine holder shaft generally parallel to the path of the needle as it is moved in the vicinity of the knotter, and because of the needle moving rather closely along the stationary twine guide positioned just forwardly of the path of the billhook, and also along the twine gripping area of the twine holder, the secondary twine portion is always correctly positioned relative to the path of the bill hook so that the risk of the secondary twine portion escaping from the grasp of the billhook is completely eliminated irrespective of whether or not the crop to be baled is tough or resilient and irrespective of the density at which the material is being baled. Thus, the likelihood of mis-ties is much reduced.Also, the very small dimensions of the twine holder (in comparison to existing twine holders) and the positioning of the twine holder shaft closely adjacent, and parallel to, the billhook shaft, enables the billhook to move parallel to, and closely adjacent, the lower and forward face of the twine holder in a manner so that the billhook path overlaps the major portion of the twine holder face. This again helps the billhook positively to grasp both twine portions held in the twine holder and thus reduce the risk of mis-ties.

Notwithstanding the fact that the twine holder is of an exceptionally small size, sufficient twine length is provided for the knot to be made without giving rise to any problems. This length is in part obtained by the fact that the primary twine portion extends from the twine holder in a direction away from the billhook to loop around a further member of the knotter at a distance from the billhook before it extends down to the billhook. The further member conveniently is formed by a drive component of the twine holder.

Sufficient twine length is also in part obtained from the fact that, at the beginning of each knotting cycle, both twine portions extend from the twine holder around a stationary twine guide at a distance from the twine holder and down to the bale chamber. As the billhook, during the first revolution, pushes both twine portions off the stationary guide, the twine portions extend directly down from the twine holder to the bale chamber so that additional twine length is thus obtained. Thus, the risk of pulling the twine portions out of the twine holder before a knot is completed is minimised, if not avoided.

Also notwithstanding the fact that the twine holder is exceptionally small in size, the twine portions are firmly held and prevented from slipping when this is required, and yet are allowed gradually to slip through the twine holder components at other points in the cycle. Also, because of its small dimensions, reduced power is required to drive the twine holder.

The Geneva drive mechanism between the billhook shaft and the twine holder shaft is relatively simple in design and enables the billhook to be driven continuously during each cycle whilst driving the twine holder at intervals.

When not driven, the twine holder is automatically latched in position so that any pull on the twine portions cannot distrub the timing of the twine holder. Furthermore, because of its intermittent drive, the twine holder is rotated during the knotting cycle only when it should assume another operating condition. Known twine holders are rotated gradually in timed relation with the bilihook rotation during the entire cycle of the latter. As a result, in changing from one operating condition to another, known twine holders are positioned during proportionally relatively long periods of time in intermediate positions. With the illustrated knotter, the relative time lapse for pivoting the twine holder from one operating condition to another, during the knotting cycle, is reduced. This is a considerable factor in the good performance of the knotter.

From the foregoing it will be understood by those skilled in the art that each knotter in the illustrated arrangement is of comparatively simple design, whereby it is easy to manufacture, assemble and adjust. The structure is very reliable and requires only a minimum of attention once it has left the factory. Field adjustments, if required at all, are readily accomplished and can be made by the average operator, whereby expensive harvesting delays are avoided. Variations in twine and the use of different types of twine only require minimum adjustments, if any at all. As a matter of fact, only the spring loading of the twine retainer fingers is made adjustable, as all other adjustment possibilities have been eliminated.

The number of oscillating and complicated parts and complicated drive means such as cams and cam followers, has been reduced to a minimum and most of the moving parts have rotational movement only. The remaining oscillatory components are small in size and have only small displacements. For this and other reasons, the inertia forces are less critical and hence the speed of operation of the knotter, and hence of the baler, can be increased substantially. Increased knotter speed does not adversely affect the quality of the knot tied.

Conventional knotters normally have a main drive arrangement for each knotter installed on the baler. As a baler usually employs two knotters, the two main drive means are required.

However, two or more knotters according to the present invention can be driven by a simple, single main drive arrangement.

Due to the simple design and the reduced number of moving parts, it is possible significantly to reduce the number of greasing nipples per knotter. Conventional knotters normally have six or seven greasing nipples but a knotter according to the present invention only requires one greasing nipple for both the twine holder shaft and the billhook shaft.

Also, due to the design of the knotter, the operation thereof will be affected to a lesser extent, if at all, by the vibrations of the baler, the tension in the twine, the jarring of the baler as it moves through a field, variations in the crop condition, such as tough or resilient crops causing the baler twine to jump about, moisture, dirt, crop debris and the like all subjecting the components to abrasion.

The angle of the billhook shaft relative to the bale chamber is advantageous for the reason that the billhook is positioned extremely close to the bale. Thus, a shorter loop of twine around the bale and thus also a higher bale density is obtained in that the bale is bound tighter and does not expand to take up slack in the twine band. The chosen inclination of the billhook shaft, and also of the billhook, relative to the bale chamber is also advantageous in that the load on the twine as the knot is pulled off the billhook is reduced.

Finally, it will also be understood by those skilled in the art that the cost of a knotter according to the invention and the cost of field delays and servicing are reduced substantially in comparison with similar costs of a conventional knotter.

Claims (76)

Claims

1. A knotter comprising a twine holder operable to hold, during a knot-tying operation, a primary portion and a secondary portion of twine in which a knot is to be tied and including spaced apart, generally coaxial flanges rotatable about a first axis and at least one substantially stationary twine retainer finger cooperable with two adjacent flanges to hold the primary and secondary portions of twine, and a rotary billhook rotatable about a further axis to which it is inclined, and operable to tie the knot in the primary and secondary twine portions, the first and the further axes extending parallel to each other.

2. A knotter comprising a twine holder operable to hold, during a knot-tying operating, a primary portion and a secondary portion of twine in which a knot is to be tied, the twine holder including rotary means mounted on a shaft of the twine holder for rotation, a rotary billhook attached at an angle to a shaft for rotation and operable to tie the knot in the primary and secondary portions of twine and intermittent drive means disposed between the bill hook shaft and the twine holder shaft and operable such that the bilihook shaft intermittently drives the twine holder shaft during the knot-tying operation.

3. A knotter according to claim 2, wherein the rotary means of the twine holder comprise a plurality of spaced coaxial flanges mounted on the twine holder shaft, the twine holder further comprising at least one substantially stationary twine retainer finger cooperable with two adjacent flanges to hold the primary and secondary portions of twine.

4. A knotter according to claim 1, wherein each twine holder flange has at least three sides and comprise one notch in each side edge, the notches being arranged to receive the primary and secondary twine portions prior to the latter being caught and held between the flanges and the retainer fingers.

5. A knotter according to claim 4, wherein eacK notch in each flange is generally V-shaped and is provided adjacent one corner of the flange such that, when seen in the direction of rotation of the twine holder flanges, the notches lead the associated twine holder flange corners.

6. A knotter according to claim 4 or 5, wherein the flanges are axially aligned with each other in a manner such that the notches in adjacent flanges define grooves which extend generally parallel to the twine holder shaft.

7. A knotter according to claim 6, wherein, when the twine holder is in the rest position, one of said grooves is positioned offset relative to the plane through the axes of rotation of the twine holder and billhook and is movable towards said plane during operation.

8. A knotter according to any of claims 4 to 7, wherein each twine holder flange is generally triangular in shape.

9. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the twine holder comprises four spaced twine holder flanges and three twine retainer fingers, each of the fingers being disposed between one pair of adjacent flanges.

10. A knotter according to claim 4 and any claim appended thereto, wherein a stationary knife is provided adjacent one twine holder flange in the circumscribing path of the notches therein, with the cutting edge of the knife facing in a direction opposite to the direction of rotation of the flange.

11. A knotter according to claim 10, wherein the knife blade is positioned so that the primary and secondary twine portions are cut by the rotational movement of the twine holder towards the end of the knot tying cycle of the billhook.

12. A knotter according to claim 10 or 11, wherein the cutting edge of the knife defines with a radius through the centre of the twine holder flange which passes through a point on the cutting edge a positive angle, when seen in the direction of rotation of the billhook, whereby the primary and secondary twine portions move radially outwardly of the associated flange as they slide along the knife edge during the cutting operation.

13. A knotter according to any of the claims 10 to 11, wherein the twine holder flanges and the bill hook are positioned relative to the knife blade and in use are rotated relative to each other and to the knife blade in a manner such that at the instant of twine cutting, the billhook is rotated away from the twine holder flanges and the knife blade.

14. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the twine retainer fingers comprise a first section and a second section, the first section being cooperable with the associated twine holder flanges to hold twine up to a predetermined tensile load being exerted on the twine, and the second section being cooperable with the flanges to hold the twine under a higher tensile load on the latter.

1 5. A knotter according to claim 14, wherein the first and second sections of each finger have arcuate working edges, the working edge of the second section having a radius of curvature which is smaller than the radius of curvature of the working edge of the first section.

16. A knotter according to claim 1 or 3, or any claim appended thereto, and further comprising resilient means associated with the twine retainer fingers for resiliently urging the latter between the twine holder flanges.

17. A knotter according to claim 16 and further comprising adjustment means for adjusting the force with which the twine retainer fingers areurged between the twine holder flanges.

18. A knotter according to claim 7, or any claim appended thereto, wherein at least one retainer finger comprises a hooked end positioned relative to said offset groove, when the twine holder flanges are in a rest position, in a manner such that when the twine holder flanges are rotated from the rest position with twine portions positioned in the offset groove, the hooked end wedges the twine portions between the twine retainer fingers and the associated twine holder flanges.

1 9. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the bilihook comprises a fixed jaw attached at substantially a right angle to a billhook shaft, and a movable jaw pivotable relativeto the fixed jaw, the fixed and movable jaws being rotatable in a plane parallel to and in the vicinity of the twine holder flanges.

20. A knotter according to claim 19, wherein the path of the fixed jaw substantially overlaps the twine holder flanges, when seen in the direction of the twine holder shaft.

21. A knotter according to claim 19 or 20, wherein the fixed jaw of the billhook has a length greater than that of the sides of the generally triangularly shaped twine holder flanges.

22. A knotter according to claim 21, wherein the fixed jaw has a length in the range of 5 to 6 cms., and wherein the sides of the twine holder flanges have a length in the range of 4 to 5 cms.

23. A knotter according to any of claims 1 9 to 21, wherein the twine holder flanges and the billhook are rotatable in planes inclined at an angle in the range of 50 to 60 degrees relative to the horizontal.

24. A knotter according to any of the claims 1 9 to 23, wherein the fixed jaw has a bent tip portion extending in the direction of rotation of the billhook.

25. A knotter according to any of the claims 19 to 24, wherein the movable jaw has a heel portion arranged to cooperate with actuation means so as to open the movable jaw relative to the fixed jaw during part of the rotary movement of the billhook.

26. A knotter according to claim 25, wherein the actuation means ase in the form of a cam engageable by the heel portion of the movable jaw.

27. A knotter according to claim 26, wherein the cam is a roller having a part-spherical surface.

28. A knotter according to any of the claims 1 9 to 27, wherein resilient means are provided to urge the movable jaw to the closed position.

29. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the bill hook is rotatable through a first and second cycle during a knot-tying operation, and operable during the first cycle to position the primary and secondary portions of twine in preparation for the knot-tying operation, and operable during the second cycle to tie the knot in the primary and secondary portions.

30. A knotter according to claim 29, wherein the first and second cycles each comprise a 360 degrees movement of the billhook.

31. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the billhook.and twine holder flanges are rotatable in opposite directions.

32. A knotter according to claim 29 or 30, when appended to claims 14 or 15, wherein the twine holder is mounted for rotary movement and arranged to rotate through less than 360 degrees in timed sequence with the rotational movement of the billhook so as to move the primary and secondary twine portions relative to the twine retainer fingers, the arrangement being such that during the first cycle of the bill hook, the primary twine portion is held between the twine holder flanges and the second sections of the twine retainer fingers, and the primary and secondary twine portions are wedged between the twine holder flanges and the first portions of the twine retainer fingers towards the end of the first billhook cycle, and such that, during the second cycle of the billhook, the primary and secondary twine portions are held between the twine holder flanges and the first sections of the twine retainer fingers and moved to the second sections of the twine retainer fingers towards the end of the second bill hook cycle.

33. A knotter according to claim 1 or 3, or any claim appended thereto, wherein during the rotational movement of the billhook, the twine holder flanges are rotated through 120 degrees.

34. A knotter according to claim 1 or 3, or any claim appended thereto, wherein the twine holder flanges are rotated during only a portion of the rotational movement of the billhook.

35. A knotter according to claim 34, wherein the twine holder flanges are intermittently driven during the rotational movement of the billhook.

36. A knotter according to claim 35, when appended to claim 32, wherein the twine holder flanges are rotated over a first angular displacement at the end of the first billhook cycle and over a further angular displacement at the end of the second billhook cycle.

37. A knotter according to claim 36, wherein the twine holder flanges are angularly displaced during substantially tke last quarter of the first and the second bill hook cycles.

38. A knotter according to claim 36 or 37, wherein the twine holder flanges are rotated through substantially 60 degrees during each of the first and further angular displacements.

39. A knotter according to claim 19, or any claim appended thereto, and further comprising a first stationary twine guide extending in a transverse direction between the twine holder flanges and the path of the billhook fixed jaw, and arranged for twine portions, held in the twine holder, to bear thereagainst, and also arranged so that twine portions extending downwardly therefrom extend in the path of the billhook and are captured between the jaws of the bill hook upon rotation of the latter.

40. A knotter according to claim 39, wherein the first twine guide is disposed generally at the level of the twine holder shaft and parallel to, and in the vicinity of, the twine holder flange closest to the billhook.

41. A knotter according to claim 19, or any claim appended thereto, and further comprising a second stationary twine guide extending in a transverse direction in the vicinity of the billhook and at a level such that, during operation, the bill hook path extends between the second twine guide and the twine holder flanges, the arrangement being such that twine portions held in the twine holder may bear against the second twine guide and extend in the path of the bilihook.

42. A knotter according to claim 41, wherein the second twine guide is disposed at the side of the bill hook shaft opposite to the billhook when the latter is in the rest position, and wherein the second twine guide is positioned generally parallel to the twine holder flanges.

43. A knotter according to claim 41 or 42, wherein the second stationary twine guide comprises a free end offset relative to the billhook shaft, but still at a location within the path of the fixed jaw of the bill hook, when seen in the direction of the billhook shaft, the arrangement being such that, in operation, the billhook shifts the twine portions held in the twine holder and bearing against the second twine guide, transversely away from the bill hook shaft and over said free end in a manner to position the twine portions together and relative to the billhook in preparation for the knot to be tied therein.

44. A knotter according to claim 43, wherein at, its free end the second twine guide is bent in the direction of the billhook when the latter is in the rest position.

45. A knotter according to claim 7, or any claim appended thereto, a further comprising a third stationary twine guide positioned relative to the offset twine holder groove when the twine holder is in the rsst position in a manner to direct a twine portion towards said groove as it is being placed in the twine holder.

46. A knotter according to claim 7, or any claim appended thereto wherein the twine retainer fingers comprise a twine guide surface which, when the twine holder is in the rest position, is positioned relative to the offset twine holder groove in a manner to direct a twine portion towards said groove as it is being placed in the twine holder.

47. A knotter according to claim 1 or 3, or any claim appended thereto, and further comprising twine holder cleaners extending spirally outwardly from between the adjacent twine holder flanges in the direction of rotation of the twine holder flanges.

48. A knotter according to claim 19, or any claim appended thereto, and further comprising drive means between the bill hook and twine holder shafts for the billhook shaft to drive the twine holder shaft.

49. A knotter according to claim 48, when appended to claim 35, wherein the drive means comprise an eccentric driver cam on the bilihook shaft and a starwheel shaped driven member on the twine holder shaft engageable at intervals by the driver cam.

50. A knotter according to claim 49, wherein the starwheel shaped driven member comprises six legs equispaced around the periphery thereof.

51. A knotter according to claim 49 or 50 and further comprising locking means operable to lock the twine holder shaft in position except when driven by the driver cam.

52. A knotter according to claim 51, wherein the locking means comprise a generally cylindrical body secured on the billhook shaft and having a cut-away section at a predetermined part of its periphery defining a release surface, and starwheel type locking member secured on the twine holder shaft and having a plurality of concave sides engageable with the cylindrical body, the arrangement being such that, when any of the concave sides of the starwheel type locking member engages the cylindrical body, the twine holder shaft is locked in position, and when the release surface faces the starwheel type locking member, the twine holder shaft is unlocked.

53. A knotter according to claim 52, wherein the starwheel type locking member comprises six concave sides equispaced around the periphery thereof.

54. A knotter according to claim 52 or 53, wherein the release surface, when seen in the direction or rotation of the billhook shaft, generally leads the driver cam.

55. A knotter according to claim 48, wherein the drive means are in the form of a Geneva drive mechanism.

56. A knotter according to claim 6 or any claim appended thereto, wherein the twine holder is arranged for the primary portion of twine to extend from one groove in the twine holder flanges to an adjacent groove therein during part of the knot-tying operation, and further comprises looper means at a distance from the twine holder flanges and rotatable in unison therewith, the looper means being operable to form a loop in the primary portion of twine between the free end thereof held in said first twine holder groove and the point at which the primary twine portion is held in the adjacent twine holder groove, so as to provide a sufficient length of primary twine portion for the knot tying operation.

57. A knotter according to claim 56, wherein the looper means are provided at the side of the twine holder facing away from the billhook.

58. A knotter according to claim 56 or 57, wherein the looper means are of the starwheel type comprising at least as many legs as there are grooves in the twine holder flanges.

59. A knotter according to claim 58, wherein adjacent legs of the starwheel type looper means form twine receiving pockets therebetween which are generally aligned with the grooves in the twine holder flanges.

60. A knotter according to claim 59, and further comprising a fourth stationary twine guide positioned relative to one of the pockets in the looper means when the twine holder is in the rest position in a manner to direct a twine portion towards said pocket as it is being placed in the twine holder.

61. A knotter according to any of the claims 58 to 60, and further comprising a fifth stationary twine guide cooperable with the legs of the looper means to trap twine therebehind after placement in one of said pockets and after subsequent rotation of the twine holder and looper means.

62. A knotter according to claim 61, wherein the fifth stationary twine guide is provided at the side of the looper means facing away from the twine holder and extends generally parallel to the rotary axis of the twine holder and the looper means.

63. A knotter according to any of the claims 58 to 62, wherein the looper means comprise twice as many legs as there are twine holder grooves, pairs of adjacent legs cooperating to form the loop in the primary portion of twine.

64. A knotter according to any of the claims 56 to 63, when appended to any of claims 49 to 54, wherein the looper means are formed by the starwheel shaped driven member on the twine holder shaft.

65. A knotter according to claim 64, when appended to claim 58 or 59, wherein the starwheel shaped driven member comprises twice as many legs as there are twine holder grooves, and wherein the fifth stationary twine guide is arcuate in shape at its end facing the starwheel shaped member and has a width at this end such that it overlaps two adjacent legs of the starwheel shaped member when the latter is in the rest position.

66. An agricultural baler embodying a knotter in accordance with any of the preceding claims, the knotter being mounted on the top wall of a bale chamber with the billhook extending through an aperture in said top wall and rotatable in a plane inclined relative to the horizontal in the range of 50 to 60 degrees.

67. A baler according to claim 66, and embodying two knotters which are driven by common drive means comprising a single main shaft with a single gear segment thereon operable intermittently to mesh with a single gear which itself is drivingly coupled to each knotter through a single flexible drive transmission means.

68. A baler according to claim 67, wherein the single flexible drive transmission means comprises a chain arranged to mesh with sprockets associated with the respective knotters.

69. A baler according to any of the claims 66 to 68 when appended to claim 39 or 40, and further comprising a twine carrying needle movable through the bale chamber to place a twine portion in the twine holder, the needle being arranged to pass closely adjacent said first stationary twine guide to place the twine portion thereagainst.

70. A baler according to claim 66 or 67, when appended to any of claims 41 to 44, and further comprising a twine carrying needle movable through the bale chamber to place a twine portion in the twine holder, the needle being arranged to pass closely adjacent said second stationary twine guide to place the twine portion thereagainst.

71. A baler according to any of the claims 63 to 65, when appended to claim 5, and further comprising a twine carrying needle movable through the bale chamber to place a twine portion in the twine holder, the needle being arranged to be movable closely adjacent said offset groove in a direction generally parallel to the twine holder shaft.

72. A baler according to any of the claims 63 to 68, and further comprising a twine guide disposed within the bale chamber at a location below the aperture therein and generally below the knotter billhook so that the primary twine portion, as it is held in the twine holder, bears thereagainst during the knot-tying operation.

73. A baler according to claim 72, wherein the twine guide in the bale chamber is in the form of a.

guide roller.

74. A baler according to claim 72 or 73, and further comprising shield means in the bale chamber for shielding the twine guide therein from material to be baled.

75. A knotter substantially as herein particularly described with reference to the accompanying drawings.

76. An agricultural baler substantially as herein particularly described with reference to the accompanying drawings.