Automatic height control for a harvester header

In a crop harvester having a body and a source of electrical power and carrying a forward mounted gatherer including a crop handling portion having a frame and pivotally connected to the body for relative vertical movement and including a forward mounted crop engaging portion floatably connected to the frame of the crop handling portion, the floatable connection providing a range of vertical floating movement of the crop engaging portion relative to the crop handling portion and including a movable sensor element carried by the frame of the crop handling portion, the disposition of said element relative to the frame being responsive to said floating movement and representative of the position of at least a portion of the crop engaging portion within its range of relative vertical movement, an improved automatic height control system for the gatherer comprising:

• power lift means having raise and lower portions respectively operable, responsive to an electrical signal, to raise and lower the crop handling portion of the gatherer relative to the body of the harvester;
• a position sensor switch module including:
• a wiper arm carrying a connecting brush assembly and coupled directly to the sensor element for movement with it;
• a switch body journalled on the wiper and held against rotation by the frame of the crop handling portion;
• a contact assembly mounted in the body and carrying a plurality of contacts including a common input contact connectable with the electric power source and, spaced from it, a group of side-by-side output contacts, the contacts being disposed so as to be slidingly engageable by the connecting brush assembly with the brush assembly spanning and electronically connecting the common contact with one or more of the output contacts;
• and
• selector switching means including a manual selector switch operable to make a first output contact connectable with the raise portion of the power lift means and a second output contact connectable with the lower portion of the lift means, the disposition of said contacts thus establishing an operating height set point on either side of which the lift means is electrically signaled to raise or lower the gatherer crop handling portion responsive to vertical floating displacement of at least a portion of the crop engaging portion within a limited float range selectively established by means of the selector switching means and the relative disposition of the output contacts made connectable by manipulation of said selector switch.

In an automatic header height control system for a mobile harvester having a body and including an electric power source and carrying a pivotally mounted harvesting header having a frame and including power lift means having raise and lower portions for pivoting the header to control its operating height and a forward transversely extending crop engaging structure floatingly connected to the frame of the header for relative vertical movement, the crop engaging structure including at least one ground following feeler element for engaging and following the ground surface, a sensor transducer combination comprising:

• a rotatable sensor element carried by the header frame and connected to the crop engaging structure so that its rotational position relative to the header frame represents the relative vertical relationship of the crop engaging structure to the header frame responsive to the feeler element;
• a position sensor switch including:
• a switch body carried in a fixed relationship to the header frame;
• a plurality of contacts carried by the body and lying substantially in a common plane and including a common contact connectable with the electric power source and, spaced from it, an array of side-by-side uncommitted output contacts;
• a wiper arm assembly operatively associated with the body and coupled to the sensor element for rotational movement therewith and carrying a connecting brush assembly disposed so that movement of the wiper arm assembly moves the brush assembly in sliding engagement with the contacts, making an electrical connection between the common contact and at least one of the output contacts;
• and
• selector switching means including a selector switch for selectively associating respective first and second uncommitted contacts with the raise and lower portions respectively of the power lift means whereby a third uncommitted contact intermediate between said first and second contacts remains unconnectable with the power lift means, thus establishing a dead band corresponding to an intermediate portion of a selected range of operating height of the header measured in terms of the vertical relationship between the floating crop engaging structure and the header frame.

In an automatic crop harvesting header height control system in which a sensor shaft is rotatably mounted on a header, its rotational position representative of the height of a portion of the header above a field surface and including electro-hydraulic power means for raising and lowering the header, a sensor switch comprising:

• a wiper arm assembly directly coupled to the sensor shaft for rotational movement therewith and carrying a generally radially extending connecting brush assembly, the coupling with the shaft including a cylindrical bearing journal portion engaging and concentric with the shaft;
• a switch body having an inner wall including a bearing bore for journalling the wiper arm bearing journal portion and a connector socket opening and a continuous side wall extending outwards from the inner wall and including means for engaging the header frame so as to maintain the body in a fixed rotational relationship with the header frame;
• a contact assembly carried on the inner wall and spanning the socket connector opening and including an array of spaced side-by-side output contacts and a common input contact radially spaced from the array of output contacts, all the contacts being disposed so that as the rotational position of the wiper arm assembly changes, responsive to movement of the sensor shaft, the connecting brush assembly moves in sliding engagement with the contacts so as to maintain an electrical connection between the common contact and at least one of the output contacts, the plurality of position-related discrete connection combinations provided by the sensor switch facilitating the provision of selective automatic control of header operating height in any one of a corresponding plurality of selected ranges.

In an automatic gatherer height control system for a mobile harvester having an operator station and a source of electrical power and carrying a forward gathering unit pivotally attached to the harvester body and including power lift means having respective raise and lower portions operable responsive to an electrical signal to raise or lower the gatherer unit to change its operating height, the combination comprising:

• a movable sensor element carried by the gatherer unit;
• ground following mechanical means connected to the sensor element and operatively associated with the gatherer unit so that the position of said element is responsive to the height of the gatherer unit above the ground at least within a floating range defined by the ground following means;
• a first range indicator element movably carried by the gatherer unit;
• linkage means connected between the sensor element and the first range indicator element so that movement of said element relative to the gatherer unit is responsive to movement of the sensor element;
• a second range indicator element fixed to the gatherer unit adjacent the first range indicator element so that the relative positions of said indicator elements provides a visual indication of the disposition of the gatherer unit within the floating range as long as the gatherer unit is operating within that range;
• a position sensor switch including an input element coupled directly to the sensor element and a body carried in a fixed relationship to the gatherer unit and including a plurality of electrical contacts, including at least one input contact connected to the electrical power source and a plurality of output contacts, the input element including means for selectively electrically connecting the input contact to the output contacts so that the movement of the input element in unison with the sensor element results in the electrical connection of the input contact to any one or more of the output contacts;
• and
• selector switching means for variously and selectively connecting the output contacts to the respective raise and lower portions of the power lift system so as to signal those lift portions to raise or lower the gatherer unit as appropriate in response to movement of the sensor element whereby the gatherer unit is selectively operable in any one of a plurality of operating height ranges each range having a nominal range having an upper and a lower limit, the upper limit of the uppermost range and the lower limit of the lowermost range establishing an overall aggregate automatic height control range.