Patent Description:
During use, crop material can potentially wrap around the sprockets and the sprocket drive shaft. This can lead to mechanical malfunctions and excessive wear, and, when not properly maintained, accumulated crop materials may present a fire hazard.

To address this problem, typical feeder conveyors have an anti-wrap system comprising covers and shields that inhibit the accumulation of crop material on and around the sprockets and top shaft. For example, it is known to provide a system of plastic anti-wrap covers surrounding the conveyor top shaft drive sprockets, and metal shaft covers spanning between the plastic sprocket covers to enclose the top shaft. The covers are rigidly mounted to the feeder house (e.g., to a center structure located within the conveyor loop).

It has been found, however, that the top shaft and sprockets can deflect due to chain tension and crop load. When this happens, the top shaft and sprockets can come into hard contact with the stationary anti-wrap components, causing premature part wear. Furthermore, this deflection can allow gaps to open between the sprocket covers and the shaft covers, allowing for crop ingress into the area around the spinning shaft that is meant to be kept debris-free.

The inventors have determined that the state of the art can still be improved.

This description of the background is provided to assist with an understanding of the following explanations of exemplary embodiments, and is not an admission that any or all of this background information is necessarily prior art.

Document <CIT> discloses a feeder assembly according the preamble of claim <NUM>.

In a first exemplary aspect, there is provided a feeder assembly comprising: a feeder housing; a shaft mounted to rotate relative to the feeder housing about a center axis; a first rotary drive mounted to rotate with the shaft at a first axial position along the shaft; a second rotary drive mounted to rotate with the shaft at a second axial position along the shaft, the second axial position being spaced along the center axis from the first axial position; and an anti-wrap cover assembly extending an entire distance from the first rotary drive to the second rotary drive and at least partially surrounding the first rotary drive, the second rotary drive, and the shaft between the first rotary drive and the second rotary drive. The anti-wrap cover assembly is rotatably mounted to at least one of the first rotary drive, the second rotary drive and the shaft. A connector joins the feeder housing to the anti-wrap cover assembly and is configured to allow the anti-wrap cover assembly to move through a predetermined limited range of motion relative to the feeder housing.

In another exemplary aspect, there is provided an agricultural vehicle comprising: a chassis configured for movement on a surface; a header configured to remove crop material from the surface; and a feeder assembly as described in any one or more of the foregoing aspects and examples.

Embodiments will now be described, strictly by way of example, with reference to the accompanying drawings, in which:.

The drawing figures depict one or more implementations in accordance with the present concepts, by way of example only, not by way of limitations. The examples are shown in conjunction with an agricultural combine harvester, but have applicability in any similar agricultural vehicle, such as a windrower.

<FIG> show an exemplary embodiment of an agricultural vehicle <NUM> in the form of a combine harvester, having an anti-wrap cover assembly. The vehicle <NUM> generally includes a chassis <NUM> and a header <NUM> carried by the chassis <NUM>. The chassis <NUM> is supported on driving wheels <NUM> (e.g., tracked wheels or pneumatic tires), as known in the art. The vehicle <NUM> is configured to move in a forward direction, illustrated as arrow F, during harvesting operations.

The header <NUM> is connected to the chassis <NUM> by a feeder assembly <NUM>, which includes a conveyor <NUM> configured to collect crop material and direct it to a threshing and separating system <NUM> inside the vehicle <NUM>. Such threshing and separating systems <NUM> are known in the art and need not be described in detail herein. The feeder assembly <NUM> may be a simple rigid connection or an articulated connection comprising one or more linkage arms and/or feeder housing actuators (e.g., hydraulic pistons/cylinder actuators) that operate as housing position control mechanisms, as known in the art.

It will be appreciated that the header <NUM> and other parts described and illustrated herein do not necessarily need to be included on a combine harvester, but can be incorporated in other agricultural vehicles such as mowers, or provided as standalone replacement parts.

As shown in <FIG>, the conveyor <NUM> comprises a plurality of chains <NUM> that support a plurality of slats <NUM>. The chains <NUM> and slats <NUM> are contained within a housing <NUM>. The housing <NUM> extends from an inlet opening <NUM> at the header <NUM>, to an outlet opening <NUM> at the chassis <NUM>. The conveyor <NUM> is supported adjacent the inlet opening <NUM> by a front drum <NUM>, and at the rear opening <NUM> by a top shaft <NUM>.

The top shaft <NUM> is configured to rotate about a center axis <NUM>'. A number of sprockets <NUM> are rotationally fixed to the top shaft <NUM> and in toothed engagement with the chains <NUM>. Thus, the sprockets <NUM> are configured to transmit rotational torque from the top shaft <NUM> to the chains <NUM>. The top shaft <NUM> may be driven by a motor and gearbox <NUM> (shown schematically), or it may be an unpowered idler shaft. In either case, the sprockets <NUM> rotate with the top shaft <NUM> to provide a timing function to cause all of the chains <NUM> to rotate in unison. In <FIG>, only one chain <NUM> and sprocket <NUM> are visible, but it will be understood that multiple chains <NUM> and sprockets <NUM> are provided along the width of the feeder assembly <NUM> (i.e., into the depth of the page in <FIG>). For example, <FIG> shows four sprockets <NUM> attached to the top shaft <NUM>, at respective locations spaced along the central axis <NUM>'.

The conveyor <NUM> in this embodiment comprises flexible conveyors in the form of chains <NUM>, and rotary drives in the form of sprockets <NUM>. However, it will be appreciated that other embodiments may use flexible conveyors in the form of belts (e.g., flat, grooved, v-belts, etc.), and rotary drives in the form of flat or grooved pulleys. The conveyor <NUM> defines an operating path that surrounds a central housing frame <NUM>, which is mounted to the housing <NUM>.

Referring now more specifically to <FIG>, a portion of the top shaft <NUM> between at least two adjacent sprockets <NUM> is at least partially surrounded by an anti-wrap cover assembly <NUM> that is configured to inhibit crop material from wrapping around the top shaft <NUM>. More preferably, the anti-wrap cover assembly <NUM> spans the top shaft <NUM> between each adjacent pair of sprockets <NUM>, and at least partially surrounds (and more preferably fully surrounds) the top shaft <NUM> circumferentially about the center axis <NUM>'. The anti-wrap cover assembly <NUM> also preferably surrounds portions of each sprocket <NUM>.

The anti-wrap cover assembly <NUM> may be formed by any suitable number or configuration of parts. In the shown embodiment, the anti-wrap cover assembly <NUM> comprises a separate sub-assembly <NUM>' located between each adjacent pair of sprockets <NUM>. Each sub-assembly <NUM>' comprises a first drive cover <NUM> surrounding a portion of a first sprocket <NUM>, a second drive cover <NUM> surrounding a portion of a second sprocket <NUM>, and a shaft cover <NUM> extending from the first drive cover <NUM> to the second drive cover <NUM>. The first drive cover <NUM> may be assembled from two or more parts 134a, 134b that are secured together to surround the central axis <NUM>'. Similarly, the second drive cover <NUM> may be assembled from two or more parts 136a, 136b that are secured together to surround the central axis <NUM>'. Likewise, the shaft cover <NUM> may comprise opposed housing members 138a, 138b that are attached to each other to surround the portion of the top shaft <NUM> extending from the first sprocket <NUM> to the second sprocket <NUM>.

In some cases, the various parts of the anti-wrap cover assembly <NUM> may be interchangeable to facilitate ease of manufacture and cost savings. For example, the upper first drive cover part 134a may be identical to the lower second drive cover part 136b, and the lower first drive cover part 134b may be identical to the upper second drive cover part 136a. The two shaft cover parts 138a, 138b also may be identical. In addition, all or a portion of each sub-assembly <NUM>' may be identical to one or more other subassemblies <NUM>'. For example, the respective first and second drive covers <NUM>, <NUM> of each sub-assembly <NUM>' may be identical to each other. Similarly, the shaft covers <NUM> of each sub-assembly <NUM>' may be identical to each other, or they may be provided in different lengths to accommodate different spacing between different pairs of adjacent sprockets <NUM>.

Each sub-assembly <NUM>' may be connected to each adjacent sub-assembly <NUM>'. For example, bolts or the like may be used to connect the first drive cover <NUM> of one sub-assembly <NUM>' to the second drive cover <NUM> of an adjacent sub-assembly <NUM>'.

Referring to <FIG>, the anti-wrap cover assembly <NUM> is mounted in a floating manner, such that it moves with the top shaft <NUM> and sprockets <NUM> as those parts might deflect or otherwise shift during use. In the example of <FIG>, the first drive cover <NUM> and second drive cover <NUM> are each mounted in a sliding rotatable manner to a respective sprocket <NUM>. More specifically, a first sprocket 128a has a first groove <NUM> that receives a first protrusion <NUM> extending from the first drive cover <NUM>, and a second sprocket 128b has a second groove <NUM> that receives a second protrusion <NUM> extending from the second drive cover <NUM>.

In this example, the first and second grooves <NUM>, <NUM> each define a respective bearing face, and the first and second protrusions <NUM>, <NUM> each define a respective bearing counterface that is in sliding contact with the respective bearing face. The bearing faces and counterfaces preferably comprise materials selected to provide long service life. For example, the bearing faces may be formed of smooth steel, and the counterfaces may be formed of durable plastic, and lubricating oil or grease may be provided to reduce friction. The bearing faces and counterfaces also may comprise sleeves of low-friction material (e.g., ultrahigh molecular weight polyethylene or polytetrafluoroethylene), self-lubricating plastic, or a material such as sintered bronze or the like to help retain lubricating oil.

In this example, the first and second grooves <NUM>, <NUM> are each defined as a respective annular groove (i.e., a circular groove that is centered on the center axis <NUM>', and extends into a side of the sprocket <NUM> along the direction of the center axis <NUM>'). Other examples may have different arrangements of bearing faces and counterfaces to provide relative rotation between the anti-wrap cover assembly and the top shaft <NUM> and sprockets <NUM>. For example, the annular grooves may be replaced with circumferential grooves or the like. As another example, the annular grooves may be replaced with notches (i.e., a groove that is open on one side). Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

In this embodiment, the shaft cover <NUM> is mounted to the first drive cover <NUM> and the adjacent second drive cover <NUM>, extends the entire distance from the first drive cover <NUM> and the second drive cover <NUM>, and is not in contact with the top shaft <NUM>. The shaft cover <NUM> may completely enclose the top shaft <NUM>, or it may include openings for service or draining liquid, or openings where ingress of crop materials is not likely to occur.

The anti-wrap cover assembly <NUM> also may include features such as seals or the like to help prevent ingress of crop materials or moisture. For example, the sprockets <NUM> and first and second drive covers <NUM>, <NUM> may include interleaved portions that form a labyrinth seal <NUM> to help prevent material passage.

<FIG> show alternative examples of an anti-wrap cover assembly <NUM> mounted in a floating manner to the top shaft <NUM> and sprockets <NUM>.

In <FIG>, the first and second drive covers <NUM>, <NUM> are mounted on the sprocket <NUM> by bearings <NUM>. In this case, the grooves <NUM>, <NUM> and protrusions <NUM>, <NUM> may be omitted, or included as labyrinth seals.

In <FIG>, the first and second drive covers <NUM>, <NUM> are mounted to the top shaft <NUM> by bearings <NUM>. Here again, the grooves <NUM>, <NUM> and protrusions <NUM>, <NUM> may be omitted, or included as labyrinth seals.

In <FIG>, the shaft cover <NUM> is mounted to the top shaft <NUM> by bearings <NUM>, and the first and second drive covers <NUM>, <NUM> are mounted to the shaft cover <NUM>. It would also be possible to mount the shaft cover <NUM> to the sprockets <NUM> by bearings.

<FIG> also shows an alternative construction of the sprocket <NUM> and top shaft <NUM> assembly. Namely, top shaft <NUM> is formed as a tube, and the sprockets <NUM> are welded or otherwise directly to the top shaft <NUM>. In this case, the lateral spacing of the sprockets <NUM> is permanently fixed. The tubular top shaft <NUM> may be driven directly by the motor <NUM>, or it may be mounted by splines or the like on a driveshaft <NUM> that is driven by the motor <NUM>. The top shaft <NUM> also may be an idler shaft that is not directly driven about its axis. In this case, the drive covers <NUM>, <NUM> and shaft cover <NUM> may float laterally with the sprockets <NUM> within the width of the housing, and the shaft <NUM> may be constrained laterally by bearings, shim washers, and the like. This variation can also be applied to other embodiments, such as those described herein.

In each of the foregoing examples, any kind of bearing or bushing can be used to provide a relatively low-friction connection between the parts.

In operation, the anti-wrap cover assembly <NUM> moves along with the top shaft <NUM> and sprockets <NUM> as they might deflect during use. However, the anti-wrap cover assembly <NUM> must be restrained from freely rotating with the top shaft <NUM> and sprockets <NUM>. Thus, a connector is provided to allow the anti-wrap cover assembly <NUM> to float with the top shaft <NUM> and sprockets <NUM>, while limiting rotation with the top shaft <NUM> and sprockets <NUM>. <FIG> illustrate various examples of connectors <NUM> that may be used with embodiments.

Referring to <FIG>, in one example, the connector <NUM> may comprise a pin 156a that fits into a slot 156b. The pin 156a could have any cross-sectional shape (e.g., circular, square, rectangular, etc.) In <FIG>, the pin 156a is shaped as a tab having a rectangular cross-section, with a larger height than width, but the pin 156a could have any number of dimensions or orientations. The pin 156a is fixed to one of the anti-wrap cover assembly <NUM> and the housing <NUM>, and the slot 156b is provided on the other of the anti-wrap cover assembly <NUM> and the housing <NUM>. In this case, the pin 156a is fixed to the housing <NUM>, such as by being attached to the central housing frame <NUM>, and the slot 156b is formed in the anti-wrap cover assembly <NUM>, such as by being formed as a pocket between two adjacent drive covers <NUM>, <NUM> (see, e.g., <FIG>). The slot 156b is larger than the pin 156a, so as to form a gap <NUM>. The gap <NUM> allows the anti-wrap cover assembly <NUM> to move through a predetermined range of movement relative to the housing <NUM>. The range of movement preferably is sufficient to accommodate expected deflection of the top shaft <NUM> during operation. For example, the gap <NUM> may be sized to allow movement up and down, forwards and backwards, and left and right (all with respect to the forward direction F). The gap <NUM> also may allow the anti-wrap cover assembly <NUM> to rotate somewhat relative to the housing <NUM> (i.e., rotate along with the top shaft <NUM> through a limited range).

The connector <NUM> also may include other useful features. For example, the pin 156a or slot 156b may include or be formed as an elastic or shock-absorbing material, to reduce impact shock loads. As another example, the connector <NUM> may be surrounded by a flexible boot <NUM> to help prevent the ingress of crop materials. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

<FIG> shows another exemplary embodiment, in which the connector <NUM> comprises a pin 156a mounted to the anti-wrap cover assembly <NUM>, and a slot 156b provided in the housing <NUM>. In this case, one or more springs <NUM> are provided between the pin 156a and the walls of the slot 156b, to provide force attenuation and a positional biasing (e.g., self-centering) function. Such springs <NUM> could, of course, also be used with other embodiments of connectors <NUM>.

<FIG> shows another exemplary embodiment, in which the connector <NUM> is provided in the form of one or more straps <NUM> that join the anti-wrap cover assembly <NUM> to the housing <NUM>. Such straps <NUM> may comprise fabric or elastomer materials, metal (e.g., metal weave or chains), plastic materials, or the like.

<FIG> shows another exemplary embodiment, in which the connector <NUM> is provided in the form of a lost-motion linkage. The linkage is formed by a rod 166a that is rotationally fixed at one end to the housing <NUM> (e.g., at the central housing frame <NUM> or elsewhere), and slidingly received in a slot 166b on the anti-wrap cover assembly <NUM> (the opposite arrangement can also be used). As with the other examples, the linkage allows the anti-wrap cover assembly <NUM> to move through a limited range of motion relative to the housing <NUM>, while floating along with deflections in the top shaft <NUM>.

Embodiments such as those described herein are expected to provide a significant benefit over known anti-wrap assemblies. The floating anti-wrap cover assembly moves freely with the top shaft and sprockets as the top shaft deflects, thereby preventing hard contact between the anti-wrap cover and the sprockets and/or top shaft. This allows a tight fit between the anti-wrap cover and the rotating components, leading to improved isolation from crop materials. This also reduces wear of the anti-wrap cover.

Claim 1:
A feeder assembly (<NUM>) comprising:
a feeder housing (<NUM>);
a shaft (<NUM>) mounted to rotate relative to the feeder housing about a center axis (<NUM>');
a first rotary drive (<NUM>) mounted to rotate with the shaft at a first axial position along the shaft;
a second rotary drive (<NUM>) mounted to rotate with the shaft at a second axial position along the shaft, the second axial position being spaced along the center axis from the first axial position;
an anti-wrap cover assembly (<NUM>) extending an entire distance from the first rotary drive to the second rotary drive and at least partially surrounding the first rotary drive, the second rotary drive, and the shaft between the first rotary drive and the second rotary drive, the anti-wrap cover assembly being rotatably mounted to at least one of the first rotary drive, the second rotary drive and the shaft; and
a connector (<NUM>) joining the feeder housing to the anti-wrap cover assembly characterized in that the connector (<NUM>) is configured to allow the anti-wrap cover assembly (<NUM>) to move through a predetermined limited range of motion relative to the feeder housing (<NUM>).