Abstract: The hydraulic flotation circuit for the header of a windrower or other harvester utilizes a pair of precharged gas accumulators that are always in open communication with the flotation cylinders of the circuit. One of the accumulators is set at a relatively high precharge pressure, while the other is set at a much lower precharge pressure. If the header chosen for attachment to the harvester is relatively heavy, the accumulator with the higher precharge pressure provides the flotation bias, while if the header is relatively light, the accumulator having the lower precharge pressure comes into play.

Abstract: A self-propelled farm machine includes a rotatable air inlet screen assembly having a rotatable member and a surrounding contact surface with a positive seal therebetween. The preferred seal is composed of flexible, resilient material and includes a body portion circumscribing the rotatable member and in sealing engagement therewith, a disk-shaped skirt circumscribing the body portion and flexed into wiping engagement with the contact surface, and a transition section therebetween.

Abstract: The windrower or other harvester has a hydraulic lift circuit for its header that includes a pair of double-acting cylinders which operate in concert to raise the header and provide a solid, lower limit for downward swinging of the header. The two cylinders are connected to one another in a master-slave relationship, and the slave cylinder has its return line normally blocked by a one-way check valve so that a body of fluid is trapped against the piston of the slave cylinder during field operations. This stabilizes the two cylinders to reduce header bounce.

Abstract: A harvester having hydraulically shiftable draper sections for left, right or center crop discharge has a pair of movement limiting tangs which are carried by the draper sections at either of one of two selected locations in order to enable the lateral dimension or width of the discharge opening to be varied in accordance with crop conditions. When the standing crop is relatively dense, the tangs are positioned in an inboard location on the draper carriages so that the width of the discharge opening is maximized. Alternately, the tangs can be positioned in outward locations on the carriages for limiting lateral movement of the latter and reducing the width of the discharge opening so that the crop materials under relatively light crop conditions are formed into a dense, interlaced windrow having a central snow and ice shedding ridge.

Abstract: Sprockets of a toothed belt drive for a double sickle harvesting header are carefully aligned relative to each other and to the toothed belt so that the belt can be twisted about its longitudinal axis during advancement along a closed loop path of travel in order to translate rotary motion about a first axis to rotary motion about a second axis which is inclined relative to the first axis. The toothed belt has semicylindrical teeth, and two idler pulleys contact a return portion of the belt to insure that the same are maintained in parallelism with grooves formed in sprockets of the mechanism in order to avoid imposition of side thrusts on the belt or undue wear on the teeth. The toothed belt reciprocates both sickles of the harvesting header in synchronous, timed fashion along directions opposite to each other so that vibrations which would otherwise be established by non-synchronous movement of the sickles are significantly dampened.

Abstract: An eccentric drive mechanism includes two shafts that are coupled to a wheel-like drive member such as a pulley, with one of the shafts being in offset relation to the other shaft and the central axis of the drive member. Each shaft represents inclined, flat wall portions in mutual inter-engagement, and the wall sections are releasably brought into a position of wedging contact with each other and to the drive member in order that the rotative position of one of the shafts is retained in a certain, predefined orientation relative to the rotative position of the other shaft and to the drive member. The drive member is supported on both sides to avoid imposition of cantilever-type loadings, and the mechanism can be readily disassembled and re-assembled when desired to realign and reposition the rotative orientation of the two shafts relative to the drive member. The eccentric shaft is coupled to a sway bar of the header for oscillation of the sickle.

Abstract: The discharge hood of an agricultural combine has a housing suspended from the bottom thereof in disposition for receiving straw from straw walkers of the combine into a rotary chopper which impacts the straw and propels it rearwardly out through a spreader, while at the same time creating a current of air flowing through the housing. A second inlet positioned forwardly adjacent the straw inlet of the housing is located to receive a stream of chaff from a forwardly disposed chaff discharge of the combine so that both the chaff and the straw are passed through the chopper, admixed into a single stream, and propelled upwardly and rearwardly from the combine to be strewn and scattered across the ground behind the advancing machine. A booster fan adjacent the chaff discharge augments the air suction created at the chaff inlet of the housing by the high-speed chopping rotor to assure conveyance of the light chaff particles across the free space between the chaff just discharged and the chopper housing.

Abstract: The cutter box which houses a cutting cylinder on a harvester has an access opening in its top wall through which an abrasive, full-length sharpening stone may be alternately inserted and removed to engage and sharpen the peripherally located knives of the cylinder as the latter is rotated. Each time the stone is rocked down into the opening for a sharpening operation, it is indexed slightly further into the opening than during the previous operation in order to accommodate the slightly reduced diameter of the cylinder due to material which has been removed from the knives and the stone during the previous sharpening operation. A cover coupled with the stone is caused to move into closing relationship with the opening as the stone is rocked out of the same and, conversely, to pull away from and expose the opening as the stone is subsequently reinserted. All of the mechanical movements involved, including indexing of the stone, may be accomplished remotely through the use of an electric motor.

Abstract: The knife is normally clamped tightly against a supporting arm by a retaining bolt, but when the bolt is sufficiently loosened, the bolt itself and the knife through which it passes may be forced radially inwardly or outwardly by shifting a transversely reciprocable slide plate in the appropriate direction along its path of travel. An oblique slot in the slide plate receives the bolt and pushes it in the selected adjusting direction as the slot is displaced transversely by shifting of the plate. A pair of counter-acting set screws serve as means for shifting the plate and for releasably retaining the same in a selected position. A long key on the slide plate slidably fits into a mating key way on the supporting arm to guide the plate in its transverse movement, and because the key extends transversely of the path of in-and-out adjusting travel of the knife, it helps absorb and resist radial loading on the knife which occurs during the cutting operation.

Abstract: The chopping cylinder has knives that extend longitudinally of the axis of rotation of the cylinder and which are twisted in such a way that their longitudinal cutting edges wind generally helically around the periphery of the cylinder so that a scissor-like shearing cut is obtained as the knives move past a cooperating shearbar. Special crop flow directors are bolted to the inner faces of the knives between supporting spiders for the knives so as to intercept the crop flow headed toward the interior of the cylinder following severance and to maintain the same adjacent the outer periphery of the cylinder during the movement of the crop material around and with the cylinder to a point of discharge. Special mounting hardware permits the individual directors to be attached directly to the knives in a manner to increase the efficiency and performance of the cylinder.

Abstract: The windrow pickup header of a forage harvester is supported at least in part by gauging means that senses rises and falls in the terrain in front of the header to swing the latter up and down to accommodate such unevenness in the terrain. Long, generally fore-and-aft extending arms on opposite sides of the header have caster wheels at the forwardmost, free ends thereof and have inturned sections at their opposite ends which are fixed to the header adjacent the top of the latter and spaced substantially above the swinging axis of the header so that any rearwardly directed force applied to the caster wheels is transmitted through the arms to the top of the header to swing the same upwardly to overcome the force, rather than causing the header to buckle downwardly under as a result of the force application.