Patent Description:
Balers for producing parallelepiped bales in their baling chambers, so-called square balers, are equipped with knotter tables including a plurality of knotter assemblies mounted on a common knotter gear drive shaft. Each knotter assembly ties a twine loop about finished bales formed in bale chambers of the balers. Each knotter assembly includes a knotter gear which slides axially onto the knotter gear drive shaft.

Should the knotter gear need to be replaced the entire knotter assembly must be removed axially from the knotter gear drive shaft along with additional mechanisms such as the tucker finger cam, brake, shaft support, bearing and other components. The time and effort required to remove the knotter gear and other mechanisms is significant.

There is a need for improvements in the construction of such knotter assemblies that will reduce the amount of time and effort required to replace a broken or worn knotter gear. <CIT> discloses a knotter drive apparatus for a baler wherein each knotter assembly comprises a first and a second knotter gear sector.

The present invention is directed to a knotter drive apparatus for a baler as defined by appended claim <NUM>. Preferred aspects are defined by the dependent claims.

Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following disclosure when taken in conjunction with the accompanying drawings.

Preliminarily, it is to be noted that the terms "right" and "left" are in accordance with an observer standing behind and facing in a forward direction of travel of a baler equipped with a tying table constructed in accordance with the present invention.

Referring now to <FIG>, there is shown a large square baler <NUM> including a main frame <NUM> supported on ground wheels <NUM> for being towed across a field containing windrows of crop to be baled. The main frame <NUM> includes a baling chamber <NUM> extending longitudinally from a forward central location of the baler <NUM>. A crop pick-up and conditioning arrangement <NUM> is provided at a front underside location of the main frame <NUM> and feeds gathered crop through a crop delivery chute <NUM> that curves upwardly and rearwardly from the pick-up and conditioning arrangement <NUM> and delivers crop through an opening (not shown) provided in the baling chamber bottom wall from where it is periodically engaged by a reciprocating plunger (not shown) and pushed to the rear to form a compressed bale of crop. A knotter table <NUM> provides a system for tying six loops of twine about a large parallelepiped bale formed in the baling chamber <NUM>. It is noted that for different sizes of balers a knotter table for tying a different number of loops of twine may be used without departing from the principles of the present invention.

Referring now to <FIG>, an enlarged view is shown of the knotter table <NUM> for use with the large square baler <NUM> having a forward direction of travel as indicated by an arrow F. The knotter table <NUM> includes a support frame <NUM> comprising a bottom wall or floor <NUM> including L-shaped right- and left-hand bottom wall segments 14R and <NUM> respectively being formed by inwardly bent, L-shaped portions of right- and left-hand side walls 16R and <NUM>. The bottom wall further includes a plurality central bottom wall segments <NUM> comprising downwardly opening, longitudinally extending channel members that are spaced transversely from each other and from the short legs of the wall segments 14R and <NUM> to define a plurality of longitudinal needle slots <NUM> for respectively permitting a like number of twine-carrying needles (not shown) to swing upwardly through them during a tying cycle for securing a plurality of sets of twine strands together to form loops of twine about a bale formed in a baling chamber having a rear top region including a plurality of channel members <NUM> located within and supporting the knotter table bottom wall segments <NUM>.

A central component of the knotter table <NUM> is a knotter gear drive shaft <NUM> extending transversely to the direction of travel of the baler. Opposite end regions of the drive shaft <NUM> are respectively supported in bearing assemblies (not shown) including right and left bearing housings respectively mounted to the right and left vertical side walls 16R and <NUM>. Six identical knotter assemblies <NUM> are mounted at equally spaced locations across a middle region of the drive shaft <NUM>. The knotter gear drive shaft <NUM> has a drive shaft axis <NUM> and a shaft outside diameter <NUM>.

Referring now to <FIG>, each knotter assembly <NUM> includes a generally circular knotter gear <NUM>. The knotter gear <NUM> of <FIG> is a two piece knotter gear including first and second knotter gear sectors <NUM> and <NUM>.

The first knotter gear sector <NUM> includes a first sector hub portion <NUM> and a first sector radial portion <NUM>. A central passage <NUM> of the knotter assembly <NUM> is at least partially defined in the first sector hub portion <NUM> for receiving the knotter gear drive shaft <NUM>. The first sector radial portion <NUM> extends radially outward from the first sector hub portion <NUM> relative to the drive shaft axis <NUM>. A plurality of intermittent gear tooth segments <NUM> and <NUM> are defined on the first sector radial portion <NUM>. A side <NUM> of the knotter gear <NUM> having the gear tooth segments thereon is referred to herein as the drive side <NUM> of the knotter gear <NUM>, with the opposite side <NUM> being referred to herein as a back side of the knotter gear <NUM>. The drive side <NUM> may be described as facing in a first axial direction parallel to shaft axis <NUM>, and the back side <NUM> may be described as facing in a second axial direction opposite from the first axial direction.

The first sector hub portion <NUM> can be described as having a circumferential gap <NUM> (see <FIG>) defined therein greater than the shaft outside diameter <NUM> such that the first knotter gear sector <NUM> is removable radially, relative to the drive shaft axis <NUM>, from the knotter gear drive shaft <NUM>. In the embodiment of <FIG> the circumferential gap <NUM> spans an arc of <NUM> degrees about the shaft axis <NUM>.

The second knotter gear sector <NUM> includes a second sector hub portion <NUM> and a second sector radial portion <NUM>. The second sector hub portion <NUM> defines a further part of the central passage <NUM>. The second sector radial portion <NUM> extends radially outward from the second sector hub portion <NUM> relative to the drive shaft axis <NUM>. The second sector hub portion <NUM> can be described as closing or spanning in the circumferential gap <NUM> of the first sector hub portion <NUM> when the knotter assembly <NUM> is installed on the knotter gear drive shaft <NUM>.

In the embodiment of <FIG> the first and second knotter gear sectors <NUM> and <NUM> each comprise substantially a <NUM> degree portion of the knotter assembly <NUM> relative to the drive shaft axis <NUM> such that the first and second knotter gear sectors <NUM> and <NUM> are divided from each other at a diametrical divide <NUM> extending substantially diametrically relative to the drive shaft axis <NUM>. The first and second sector hub portions <NUM> and <NUM> include hub flanges <NUM> and <NUM>, respectively, extending parallel to each other and parallel to the diametrical divide <NUM>. The hub flanges <NUM> and <NUM> extend from the back side <NUM> of the first and second knotter gear sectors <NUM> and <NUM>. At least one connector <NUM> extends between the hub flanges <NUM> and <NUM> and connects the first and second knotter gear sectors <NUM> and <NUM> when the knotter assembly <NUM> is installed on the knotter gear drive shaft <NUM>.

The first and second sector hub portions <NUM> and <NUM> can be described as being generally semi-cylindrical in shape such that when joined together they define the central passage <NUM> therethrough. The central passage <NUM> has a central axis <NUM> (see <FIG>) which is coincident with the drive shaft axis <NUM>.

In the embodiment of <FIG> the second sector radial portion <NUM> has a second plurality of intermittent gear tooth segments <NUM> and <NUM> defined on its drive side.

In the embodiment of <FIG> the central passage <NUM> is configured to closely receive the knotter gear drive shaft <NUM>, and at least one of the first and second sector hub portions <NUM> and <NUM> includes an internal groove <NUM> which is keyed to the knotter gear drive shaft <NUM> such that the knotter gear <NUM> is rotationally fixed relative to the knotter gear drive shaft <NUM>.

Each knotter assembly <NUM> further includes a knotter frame <NUM> having an upper end defined by a two-piece cylindrical head frame assembly <NUM> received on the left end of the first and second sector hub portions <NUM> and <NUM> so as to permit the knotter gear <NUM> to rotate relative to the knotter frame <NUM>. The head frame assembly <NUM> includes a main head frame portion <NUM> and a head frame cap <NUM> configured such that when the head frame cap <NUM> is bolted to the main head frame portion <NUM> the head frame assembly <NUM> circumscribes the knotter gear drive shaft <NUM> and the first and second sector hub portions <NUM> and <NUM>. The head frame assembly <NUM> is configured such that the head frame cap <NUM> must be removed from the main head frame portion <NUM> to allow the first and second knotter gear sectors <NUM> and <NUM> to be removed radially, relative to the drive shaft axis <NUM> from the knotter gear drive shaft <NUM>.

Referring now to <FIG>, an alternative embodiment of a knotter assembly is designated as <NUM> and includes a generally circular knotter gear <NUM>. The knotter gear <NUM> of <FIG> is also a two piece knotter gear including first and second knotter gear sectors <NUM> and <NUM>. In this case the first knotter gear sector <NUM> includes a first sector radial portion <NUM> which circumscribes greater than <NUM> degrees relative to the drive shaft axis. The second sector radial portion <NUM> circumscribes less than <NUM> degrees relative to the drive shaft axis <NUM>. Each of the first and second sector hub portions <NUM> and <NUM>, however, still circumscribe substantially <NUM> degrees relative to the drive shaft axis.

The first knotter gear sector <NUM> has a gap <NUM> defined therein which is larger than the shaft outside diameter <NUM> and thus permits the first knotter gear sector <NUM> to be removed radially relative to the knotter gear drive shaft <NUM> when the second knotter gear sector <NUM> is disconnected from the first knotter gear sector <NUM>.

As best shown in <FIG>, the first knotter gear sector <NUM> may include a cast in boss <NUM> having a connector passage <NUM> defined therethrough transverse to the drive shaft axis <NUM>. The second sector radial portion <NUM> of the second knotter gear sector <NUM> may have a threaded connector receptacle <NUM> defined therein and aligned with the connector passage <NUM>. At least one connector <NUM> may extend through the connector passage <NUM> into the threaded connector receptacle <NUM> to connect the first and second sector radial portions <NUM> and <NUM>. Alternatively, the boss <NUM> could be formed in the second knotter gear sector <NUM> and the threaded connector receptacle <NUM> could be formed in the first knotter gear sector <NUM>.

Also, in the knotter gear <NUM> all of the intermittent gear tooth segments <NUM>, <NUM>, <NUM> and <NUM> are located on the first sector radial portion <NUM>. In this embodiment there are no intermittent gear tooth segments on the second sector radial portion <NUM>.

<FIG> shows selected portions of another knotter assembly <NUM> including a two-piece knotter gear <NUM> including first and second substantially semi-circular knotter gear sectors <NUM> and <NUM>, similar in many respects to the knotter gear <NUM> of <FIG>. The frame assembly <NUM> has been deleted in <FIG> for ease of illustration. The difference in the knotter assembly <NUM> of <FIG> lies in the manner in which the two knotter gear sectors are held together, and in the manner in which they are mounted on the drive shaft <NUM>.

The knotter assembly <NUM> of <FIG> further includes a circumferentially continuous inner hub <NUM> having an inner hub passage <NUM> which closely receives the knotter gear drive shaft <NUM> therein. The inner hub <NUM> is not radially removable from the knotter gear drive shaft <NUM>. The inner hub <NUM> is received in the central passage of the first and second sector hub portions <NUM> and <NUM>. The first and second sector hub portions <NUM> and <NUM> include radially extending sector hub flange portions <NUM> and <NUM>, respectively. The inner hub includes a radially extending inner hub flange <NUM> which engages and is bolted to the radially extending sector hub flange portions <NUM> and <NUM> of the first and second sector hub portions <NUM> and <NUM>, respectively, such that the first and second knotter gear sectors <NUM> and <NUM> are rotationally fixed relative to the inner hub <NUM>.

In the embodiment of <FIG> the radially extending sector hub flange portions <NUM> and <NUM> are located on the drive side of the knotter gear <NUM>. A plurality of fasteners <NUM> may attach the radially extending inner hub flange <NUM> to the radially extending sector hub flange portions <NUM> and <NUM>.

<FIG> and <FIG> show another embodiment portions of a knotter assembly <NUM> similar to the knotter assembly of <FIG>, except in this case the radial flanges connecting the continuous inner hub and the first and second gear sectors are located on the back side of the knotter gear.

In <FIG> and <FIG> the knotter assembly <NUM> includes first and second gear sectors <NUM> and <NUM>. First gear sector <NUM> includes a first sector hub portion <NUM> and a first sector radial portion <NUM>. Second gear sector <NUM> includes a second sector hub portion <NUM> and a second sector radial portion <NUM>. On the back side of the first and second sector hub portions <NUM> and <NUM> are defined radially outwardly extending hub flanges, only the second radially outward extending hub flange <NUM> being visible in <FIG>.

A circumferentially continuous inner hub <NUM> is received through the first and second sector hub portions <NUM> and <NUM> and includes radially extending inner hub flange <NUM> which may be bolted to the radially outwardly extending hub flanges such as <NUM>.

<FIG> shows a further knotter assembly <NUM> which includes a one piece knotter gear <NUM>, which may be described as including one and only one knotter gear sector <NUM>.

The knotter gear sector <NUM> may be similar in construction to the first knotter gear sector <NUM> of the two piece knotter gear <NUM> of <FIG>, but in this case there is no second knotter gear sector to fill the gap in the first knotter gear sector.

Claim 1:
A knotter drive apparatus for a baler, comprising: a knotter gear drive shaft (<NUM>) having a drive shaft axis (<NUM>) and a shaft outside diameter (<NUM>); and a plurality of knotter assemblies (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) mounted on the knotter gear drive shaft (<NUM>), each knotter assembly including a first knotter gear sector (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) including a first sector hub portion (<NUM>, <NUM>, <NUM>, <NUM>) and a first sector radial portion (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein: a central passage (<NUM>) of the knotter assembly is at least partly defined in the first sector hub portion (<NUM>) for receiving the knotter gear drive shaft (<NUM>); the first sector radial portion (<NUM>) extends radially outward from the first sector hub portion (<NUM>) relative to the drive shaft axis (<NUM>), and has defined thereon a plurality of intermittent gear tooth segments (<NUM>, <NUM>); and the first knotter gear sector (<NUM>) has a circumferential gap (<NUM>) defined therein greater than the shaft outside diameter (<NUM>) such that the first knotter gear sector (<NUM>) is removable radially, relative to the drive shaft axis (<NUM>), from the knotter gear drive shaft (<NUM>), wherein each knotter assembly further comprises: a second knotter gear sector (<NUM>) including a second sector hub portion (<NUM>) and a second sector radial portion (<NUM>), wherein: the second sector hub portion (<NUM>) defines a further part of the central passage (<NUM>); the second sector radial portion (<NUM>) extends radially outward from the second sector hub portion (<NUM>) relative to the drive shaft axis (<NUM>); the second knotter gear sector (<NUM>) closes the circumferential gap (<NUM>) of the first knotter gear sector (<NUM>) when the knotter assembly is installed on the knotter gear drive shaft (<NUM>); and at least one connector (<NUM>) connects the first and second knotter gear sectors when the knotter assembly is installed on the knotter gear drive shaft, characterized in that, the first and second knotter gear sectors (<NUM>, <NUM>) each comprise substantially a <NUM> degree portion of the knotter assembly relative to the drive shaft axis (<NUM>) such that the first and second knotter gear sectors are divided from each other at a diametrical divide (<NUM>) extending substantially diametrically relative to the drive shaft axis.