CROP HARVESTING MACHINE

Abstract: A pull-type mower conditioner (10) has a support frame (12) on which a floating header (50) is mounted, via upper and lower links (64, 72) for movement between transport and working positions. Upper and lower conditioning rolls (46, 32) receive crop from the header. The upper roll (46) is mounted between a pair of bell-cranks (36) which are swingable on the frame (12) to move the upper roll (46) toward or away from the lower roll (32). A spring (78) is connected between either bell-crank (36) and the corres­ ponding lower link (72), and serves in a simple manner both as a float spring for the header (50) and for biasing the upper conditioning roll (46) toward the lower roll (32).

Description: This invention relates to a crop harvesting machine having a support frame, a floating header, an upper and lower linkage connecting the header to the frame for upward and downward swinging movement between transport and working positions of the header, a pair of conditioning rolls disposed to receive crop therebetween from the header, one said roll being mounted on swingable arm means, and spring means arranged to exert a lifting force on the header and to act on the arm means to bias the said one roll toward the other roll. Such a machine is disclosed in US-A-3797207 in which the spring arrangement is somewhat complex. An upper conditioning roll is mounted between a pair of swingable arms so that it can move toward, or away from, its companion lower roll. The arms are acted on, through a lever system, by a pair of springs which are connected to the frame of the machine and which serve to bias the upper to the lower roll. Further springs act as float springs for the header. The present invention offers a simpler arrangement. According to the invention the spring means is connected at its lower end to the lower linkage and at its upper end to the arm means. In this manner, the structure can be simplified. Preferably the geometric relationship between the spring means, the lower linkage and the arm means is such that the bias on the said roll remains substantially constant at working positions of the header. Thus there is no reduction in the biasing force applied to the shiftable conditioning roll as the header is raised in its working positions. Hence the conditioning effect on the crop remains constant. An embodiment of the invention will now be described with reference to the accompanying diagrammatic drawings in which: Fig. 1 is a left side elevational view of a combined crop harvesting machine and conditioner with a float spring arrangement showing the machine in a lowered working position; and Fig. 2 is a view like Fig. 1 but showing the machine in a raised transport position. The description which follows mentions various components as being in pairs while only the components at the left side of the machine are illustrated. It is to be understood that the unshown component is either identical to or the mirror image of the one shown. Referring now to the drawings, there is shown a pull-type crop harvesting machine 10 commonly referred to as a mower-conditioner. The machine 10 includes a main support frame 12 including a transverse cross beam 14 having downwardly extending legs 16 joined thereto adjacent its opposite ends. Each leg 16 has a wheel-support arm 18 vertically pivotally mounted on its lower end by a pivot 20 and rotatably mounted to each arm 18 is a wheel 22. A U-shaped rearwardly opening cylinder mounting bracket 24 is welded to the rear side of the beam 14 in fore-and-aft alignment with each of the legs 16. Coupled between the bracket 24 and wheel-support arm 18 at each side of the machine is an extensible and retractable hydraulic actuator 26, the actuators 26 being selectively operable for adjusting the vertical position of the frame 12 relative to the wheels. A draft tongue 28 has its distal end horizontally pivotally connected to an upper central location of the beam 14 in a well-known manner, not shown. An extensible and retractable hydraulic actuator, also not shown, would normally be connected between the tongue 28 and frame 12 for adjusting the angular position of the draft tongue relative to the beam for adjusting the path of travel of the machine 10 relative to a towing tractor (not shown) hitched to a forward end of the draft tongue. Fixed to the main frame 12 in the vicinity of each of the frame legs 16 is a fore-and-aft extending side sheet 30. A lower conditioner roll 32 extends between, and is rotatably mounted on lower forward locations of the side sheets 30. A forwardly projecting bracket 34 is fixed to a mid-height location of each of the legs 16 and an L-shaped conditioner roll support arm (i.e. a bell crank) 36 is vertically pivotally mounted to each bracket 34 by a pivot 38 extending through the arm 36 at the juncture of an upstanding leg 40 and a forwardly extending leg 42. An arcuate slot 44 is formed in each side sheet 30 on a radius about a first horizontal pivot axis defined by the pivots 38 and received through the slots 44, and rotatably mounted in the forward ends of the legs 42 are opposite ends of an upper conditioner roll 46. Thus, the uppper conditioner roll 46 is mounted for movement toward and away from the lower conditioner roll 32. Located for forming a windrow of material discharged from the conditioner rolls 32 and 46 is a shield structure 48 which is joined to and extends rearwardly from the frame 12. A header 50 is mounted in front of the conditioner rolls for cutting a crop and delivering it to the rolls to be conditioned. Specifically, the header 50 includes transversely spaced, fore-and-aft extending side panels 52 connected together at their forward ends by a transverse knockdown bar 54. An elongated transverse cutter bar 56 extends between and is supported by lower edges of the panels 52. A reel 58 is rotatably supported by the panels 52 forwardly of the cutter bar 56 so that crop engaging elements thereof sweep adjacent the cutter bar 56 and deliver crop to a cross auger 62, also having opposite ends rotatably carried by the side panels 52. The auger 62 operates to deliver the cut crop into a nip area of the conditioner rolls 32 and 46. The cutter bar, reel, auger and conditioner rolls are all driven in a conventional manner (not shown), a portion of the drive for some of these elements being located within housings 63 which extend outwardly from the side panels 52. The header 50 is suspended for vertical floating movement by a linkage including either a pair of upper links 64 with one being provided at each side of the header or a single centrally located upper link. Each upper link 64 has its forward end coupled to an upper rear location of the adjacent side panel 52 by a pivot 66 and has its rearward end coupled to a cross beam borne bracket 68 by a pivot 70. Disposed in general parallel relationship to each upper link 64 is a lower link 72 having its forward end coupled to the lower edge of the side panel 52 by a pivot 74 located below a forward portion of the auger 62 and having its rearward end coupled to the adjacent wheel support arm 18 by a pivot 76. Thus the lower links 72 and wheel support arms 18 constitute a lower linkage connecting the header 50 to the frame 12. A coil extension spring 78 is connected between the conditioner roll support arm 36 and lower link 72 at each side of the machine 10 for simultaneously biasing the upper conditioner roll 46 toward the lower conditioner roll 32 toward a normal closed position (Fig. 1) and exerting a lifting force on the header 50. Specifically, joined to, and projecting outwardly from, each of the links 72 at a location approximately one-third of the length of the link from its forward end is a peg 80. Joined to, and projecting outwardly from, the top of the upwardly extending leg 40 of each support arm 36 is a flange 82. The springs 78 each have a lower end defined by a hook 84 engaged with an adjacent one of the pegs 80 and have a threaded plug (not visible) carried at its upper end and receiving a threaded adjustment bolt 86 extending through an adjacent one of the flanges 82. It can be seen then, as viewed in the drawing, the springs 78 bias the arms 36 anti-clockwise about the pivots 38 and, hence, bias the upper roll 46 towards the lower roll 32. A desired minimum spacing between the upper and lower conditioner rolls is maintained by an adjustable down stop 88 coupled between the arm 36 and the cylinder mounting bracket 24 at each side of the machine 10. Specifically, the upwardly extending leg 40 of each arm 36 is provided with a rearwardly projecting tab 90 disposed in fore-and-aft alignment with an upper end of an adjacent one of the brackets 24. As can best be seen in Fig. 1, the down stop 88 is defined by an adjustment bolt 92 and a clevis 94, the bolt being reciprocably received in the bracket and adjustably threaded into a hole provided in the closed end of the clevis. The clevis 94 has its legs connected to the tab 90 by a pin 96. A stop nut 98 is provided on a rearward part of the bolt threads so as to prevent the latter from being damaged by slipping back and forth through the bracket 24. When cutting in adverse conditions, the machine 10 may plug due to a build-up of material in front of the conditioner rolls 32 and 46. Provided for automatically effecting opening of the gap between the conditioner rolls, in response to the header being raised to its transport position (Fig. 2) by extension of the hydraulic actuators 26, for permitting the passage of built-up crop, is a flexible, lost-motion connection linkage, here shown as a chain 100 coupled between the wheel support arm 18 and roll support arm 36 at each side of the machine. A cable could be used instead of the chain. Specifically, an elongate bracket 102 is secured to and projects rearwardly from the upstanding leg 40 of each arm 36 to a location rearwardly of the arms 18 which are each provided with a connection tab 104. The opposite ends of the chain 100 are respectively coupled to the distal end of the bracket 102 and the tab 104 by bolts 106 and 108. Because it is desired that the conditioner rolls be closed over a range of header working heights so as to properly condition crop fed thereto, the length of the chains 100 is chosen so that the chains remain slack until the header 10 has been raised to within about 50 mm. of its transport position shown in Fig. 2. The tightened chains 100 then act during this last 50 mm. of lift of the header 10 to rotate the roll support arms 36 clockwise and open the gap between the rolls 32 and 46 from a normal operating gap of, for example, about 1,5 mm to a maximum gap of about 87 mm. Further contributing to the rolls 32 and 46 operating to condition crop properly over the working range of the header 50 is the geometrical relationship between the roll support arms 36, wheel support arms 18 and float springs 78 which results in the springs 78 exerting a substantially constant closing force on the conditioner roll 46 throughout the majority of the working height range of the header 50. It is here noted an additional biasing force operating solely for urging the upper roll 46 toward the lower roll 32, may be provided by optionally mounting a tension spring 110, at each side of the vehicle, between a respective horizontal flange 112 fixed to the top of each cylinder mounting bracket 24 and a respective one of the conditioner roll arm brackets 94, optional springs 110 being shown only in Fig. 2. The operation of the harvesting machine 10 follows. Assuming the machine 10 to be located in a field from which it is desired to harvest a crop, the header 50 and hence the cutter bar 56 will be lowered to a desired cutting height by effecting retraction of the hydraulic actuators 26 to lower the frame 12 relative to the wheel support arms 18 and attached wheels 22. At the same time, the chains 100 will go slack and the conditioner roll support arm 36 will be pivoted anti-clockwise by the force of the float springs 78 until it is stopped by the adjustable down stop 88. The upper conditioner roll 46 will then be yieldably biased toward the lower conditioner roll but stopped short of contacting the latter so that a preselected gap, which may for example be in the neighbourhood of 1,5 mm, exists therebetween when no crop material is passing between the rolls. The drives for the various driven components of the machine 10 are then engaged and the machine towed across the field for harvesting the crop. As the machine 10 advances across the field, the cutter bar 56 will sever the crop which is then swept into the auger 62 by the reel 58, the auger acting to feed the crop into the gap or nip of the rolls 32 and 46 which condition the crop and expel it rearwardly to be formed into windrows by the shield structure 48. During such operation, the float springs 78 will be exerting a lifting force on the header 50 so that the latter may easily follow the terrain. The springs 78 will also be functioning to keep the upper conditioner roll 46 in biased yieldable engagement with a mat of crop material passing between the rolls. In the event that the slug of crop material should arrive at the conditioner rolls and plug the machine, the operator will stop the machine and raise it to its transport position by effecting extension of the hydraulic actuators 26. As the header 50 approaches within about 50 mm. of its transport position, the chains 100 will tighten and effect clockwise movement of the roll support arm 36 so as to widen the gap between the rolls 32 and 46 about 87 mm. so as to permit the slug of crop material to pass therebetween. Once the machine is cleaned, the actuators 26 are once again retracted to position the header 50 in its operating position. The gap between the rolls 32 and 46 may be adjusted to produce a desired amount of conditioning, so as to accommodate for varying crop conditions or crops, by adjusting the down stop 88; and, for the same purpose, more or less biasing force may respectively be applied to, or removed from, the roll support arm 36 by adding or subtracting the optional tension springs 110. Of course, changes in both the float and biasing force exerted on the roll support arms can be made by turning the adjustment bolts 86 in the appropriate directions for increasing or decreasing the force exerted by the float springs 78.

Claims: 1. A crop harvesting machine having a support frame (12), a floating header (50), an upper and lower linkage (64, 72, 18) connecting the header (50) to the frame (12) for upward and downward swinging movement between transport and working positions of the header (50), a pair of conditioning rolls (46, 32) disposed to receive crop therebetween from the header (50), one said roll (46) being mounted on swingable arm means (36), spring means (78) arranged to exert a lifting force on the header (50) and to act on the arm means (36) to bias the said one roll (46) toward the other roll (32) characterised in that the spring means (78) is connected at its lower end to the lower linkage (72) and at its upper end to the arm means (36). 2. A crop harvesting machine according to claim 1 characterised in that the arm means comprises a pair of bell cranks (36) between legs (42) of which the said one roll (46) is mounted and which are swingable on the support frame (12), and the spring means (78) is connected at its upper end to the remaining legs (40) of the bell cranks (36). 3. A crop harvesting machine according to claim 1 or 2 characterised in that the geometric relationship between the spring means (78), the lower linkage (72) and the arm means (36) is such that the bias on the said roll (46) remains substantially constant at working positions of the header (50). 4. A crop harvesting machine according to any preceeding claim in which the machine (10) is mounted on a pair of wheels (22) via wheel support arms (18) swingable about the wheel axis, and the lower linkage comprises a pair of lower links (72) and the wheel support arms (18), the lower links (72) being pivotally attached to the wheel support arms (18) characterised in that the support frame (12) is pivotally attached to the wheel support arms (18). 5. A crop harvesting machine according to claim 4 characterised in that the spring means comprise a single spring (78) on either side of the machine connected at the lower ends respectively to the lower links (72). 6. A crop harvesting machine according to claim 4 or 5 characterised in that a lost-motion linkage (100) is connected between the arm means (36) and the wheel support arms (18) so as to transmit movement of the wheel support arms (18) to the arm means (36), only on the wheel support arms (18) being raised, and thereby move the said one roll (46) away from the said other roll (32). 7. A crop harvesting machine according to claim 6 characterised in that the lost-motion linkage comprises chain means (100). 8. A crop harvesting machine according to claims 2 and 7 characterised in that a bracket (102) is rigidly attached to each said leg (42) on which the said one roll (46) is mounted and a chain (100) is connected between each bracket (102) and corresponding wheel support arm (18). 9. A crop harvesting machine according to any preceeding claim characterised in that an adjustable stop (88) is coupled between the arm means (36) and the support frame (12) so as to limit movement of the said one roll (46) toward the said other roll (32) to provide a minimum crop-receiving gap therebetween.

Inventors: WELLMAN, STANLEY PAUL
Applicants: DEERE & COMPANY
Application year: 1989
Main classification: A01D43
IPC codes: A01D43