Knife arm assembly for a sickle

The knife arm assembly for connecting a sickle drive to the knife of a sickle, has a knife arm including a cavity and an opening at one end that holds a bearing for receiving a knife pin of the sickle, and a shoulder extending at least partially about and defining a second opening at an opposite end of the cavity smaller than the first opening, and a plug disposed in the second end of the cavity adjacent the end of the bearing and enclosing the second opening, the plug being configured to be forceably movable through the cavity toward the first opening and against the bearing for forcing the bearing from the knife arm, providing easy serviceability, protection from dirt, dust, and other contaminants.

TECHNICAL FIELD

This invention relates generally to a knife arm assembly for the sickle of a header of an agricultural cutting machine, such as a combine, windrower or other crop harvesting machine, or a mower, and more particularly, for connecting a sickle knife assembly to a driven element of a drive mechanism, which is easily serviceable, provides protection from dirt, dust, and other contaminants, can be vertically self adjusting, and can reduce downtime for repair and replacement of components expected to wear over time.

BACKGROUND ART

The disclosure of U.S. Provisional Application No. 61/491,072, filed May 27, 2011, is hereby incorporated herein in its entirety by reference.

Sickles typically including cutter bars supporting a row of knives, have been used to cut plants, including, but not limited to, hay, grasses, small grains and the like, for many years.

The knives are composed of a plurality of knife or sickle sections which are mounted in side by side relation forming an elongate metal knife assembly. The elongate knife assembly is normally supported so as to slide longitudinally along an elongate stationary bar that has forwardly projecting, spaced apart guards bolted to a structural beam or knife back. The knife assembly moves back and forth in a reciprocating movement to move the knives relative to the guards so that the leading knife edges of the knives cross over the guards or through slots in the guards. This produces a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards.

In a harvesting machine, such as a combine or windrower, the knife assembly and stationary bar are typically supported in connection with a cutting head or header, and are oriented so as to extend sidewardly along a forward edge portion of structure such as a floor or pan of the header, hereinafter sometimes referred to generally as the floor. The floor or pan defines the lower periphery of a cut crop or plant flow area, which can include conveying apparatus, such as one or more augers or belts, operable in cooperation with a reel in machines so equipped, for conveying the cut plant material and crops, for instance, to a feeder inlet of a combine or windrow forming apparatus of a windrower.

Historically, many known sickle drive mechanisms have been located on the side end of the sickle, and connect to the knife assemblies utilizing connecting rods or Pitman arms, such as illustrated in Wanamaker, U.S. Pat. No. 1,622,299, issued Mar. 29, 1927, and Boyer, U.S. Pat. No. 2,332,840, issued Oct. 26, 1943. An observed shortcoming of these older drives, however, is that the drive rods or arms are obtrusively positioned in the cut plant flow area. The ball joints are advantageous as they accommodate misalignments of the knife assemblies relative to the stationary support structure, but they are inefficient for directing the motive power or drive forces in the desired direction longitudinally along the knife assemblies, that is, sidewardly along the length of the sickle. The referenced constructions also provided little or no protection from infiltration of dirt, dust and the like into interfaces between relatively moving parts, so as to be subject to accelerated wear and reduced service life.

More recent known side located sickle drives are less obtrusive and connect to the end of the knife assembly with a connection that better directs the motive power longitudinally along the knife assemblies. Reference in this regard, Regier et al., U.S. Pat. No. 7,121,074 B1 issued Oct. 17, 2006. An observed advantage of this drive it is that it utilizes epicyclical motion translated to the sideward reciprocating motion by connecting components that allow motion in one plane only, as opposed to the multiple plane motion afforded by the ball joints of the older drives, while allowing for or accommodating slight misalignment of the knife assemblies in the stationary supporting structure, the stationary bar. Also, in the Regier et al. construction, the connecting components most likely to be subject to substantial wear, namely, a pin joint, are replaceable, however, the pin joint appears to lack protection from infiltration of dirt, dust, and the like.

Other more recent sickle drives are adapted to be located in or below the floor or pan of a header or plant cutting machine, as shown in Priepke U.S. Pat. Nos. 7,810,304; 7,805,919; 7,730,709; 7,520,118; and 7,401,458, and Bich U.S. Pat. No. 8,011,272. These drives are compact, and provide an efficient manner of translating epicyclic motion to side to side sickle motion such that the motive forces are directed substantially longitudinally along the knife assemblies. However, these drives utilize knife arms that attach to the sickle knife assemblies with a rigid connection, which does not accommodate or adjust for variances in the vertical distance between the knife assemblies and the drive that can be present as a result of wear, manufacturing and assembly tolerances, and the like. The knife arms of these drives also lack accommodations for misalignments of the knife assembly relative to the fixed support structure, e.g., the stationary bar or knife back.

Reference also Bich et al. U.S. Pat. No. 8,151,547 which discloses a knife arm assembly, configured for attachment to a center drive, which suffers from some of the above referenced shortcomings, include an upwardly facing seal, and a knife head requiring an intermediary member for attachment to the knife, and removal and replacement of the knife pin of which connecting the knife head to the knife arm requires removal of the knife head.

Additionally, in the instances of both the Regier et al. and Priepke types of drives, and the knife head and arm assembly of Bich et al. U.S. Pat. No. 8,151,547, vertical misalignment between the output elements of the drive and the knife assemblies can occur, and if not eliminated or compensated for, can result in accelerated wear, excessive binding, rubbing, and increased power consumption. For instance, as the knife assemblies and supporting structure wear as a result of use, particularly the underside of the knife assemblies and associated support structure, the knives will have a tendency to gradually lower within the stationary support structure, but if they are not allowed to do so in the vicinity of the connection to the driving knife arm, additional stress will be created in the knife arm and head assembly. A known remedy for this problem is to shim or otherwise adjust or compensate for the wear, and if this in not properly done, it can result in the binding and increased wear and power consumption. Also, when a worn knife assembly is replaced by a new one, the new knife assembly may be thicker or otherwise different, and require new adjustment or shimming. Such height compensations, shimming, etc., as well as replacement of components, are time and productivity consuming, and thus can be particularly undesirable during plant cutting and harvesting operations when time is of the essence.

Thus, what is sought is apparatus for connection of a sickle drive to the knife assembly of a sickle which provides good power transmission, ease of removal, service and replacement, can have a vertical self-adjusting capability, and one or more of the other features, while overcoming one or more of the shortcomings and limitations, set forth above.

SUMMARY OF THE INVENTION

What is disclosed is a knife arm assembly for connection of a sickle drive to the knife assembly of a sickle which provides efficient power transmission, ease of removal, service and replacement, vertically self-adjustability, and one or more of the other features, while overcoming one or more of the shortcomings and limitations, set forth above.

According to a preferred aspect of the invention, the knife arm assembly includes a knife arm having a mounting end configured for attachment to the sickle drive mechanism for reciprocating sideward movement therewith and a distal end opposite the mounting end disposed to be supported in cantilever relation to the drive mechanism. The distal end has an inner surface bounding and defining a cavity and a first opening at a first end of the cavity, the first opening and the cavity having a substantially uniform first transverse extent. A bearing element is retained in and occupies at least a substantial portion of the cavity, and has an inner bearing interface surface bounding and defining a receptacle therein and including an open end generally proximate to the first opening. The bearing is configured for cooperatively receiving a knife pin of a knife head of a sickle for relative rotation of the knife arm and the knife head. The knife arm has a shoulder extending at least partially about and defining a second opening at a second end of the cavity opposite the first end, the second opening having a second transverse extent smaller than the first transverse extent. A plug is disposed in the second end of the cavity in sealed relation to the second opening. To achieve the sealed condition, the plug has a third transverse extent marginally larger or smaller than the first transverse extent and larger than the second transverse extent so as to be capable of being press fit into the second end of the cavity in sealed relation to the second opening or so as to sealably engage the shoulder about the second opening, while being restrained from passage therethrough by the shoulder. The plug is configured to be movable toward the first end of the cavity and driven against the bearing element for pressing the bearing element from the cavity through the first opening during service.

As an attendant advantage, the bearing element is removable from the arm through the first opening by application of mild force, such as can be delivered by using a mallet or hammer against a mechanic's socket, or a section of pipe or other element insertable through the second opening and positionable against the plug. The bearing element can be installed through the first opening using a press or interference fit, and this enables quick and easy removal with common tools available in a field service environment.

According to another preferred aspect of the invention, the plug includes a protuberance disposed in closing relation to the second opening which can be configured to further seal that opening, and the bearing element can bear against the plug to hold the plug against the shoulder for maintaining the sealed condition thereabout.

According to another preferred aspect of the invention, the knife arm is removably mounted on a driven element of the reciprocating sickle drive mechanism such that the distal end is disposed in cantilever relation thereto over a knife head of the sickle knife assembly, with an upstanding knife pin of the knife head cooperatively received in the receptacle of the bearing element to allow relative rotation and limited vertical movement of the knife arm and knife head.

According to still another preferred aspect of the invention, the knife pin is mounted in upstanding relation on an elongate, low profile member comprising the knife head attached by an array of fasteners, directly to an elongate structural beam or knife back of the sickle cutter. The sickle knife assembly further preferably comprises a longitudinally extending, side by side array of sickle knife sections disposed between the knife head and the beam or knife back, so as to be securely clamped or captured therebetween. The knife head preferably has holes therein or therethrough, which are aligned with standard mounting holes of the knife sections and beam, and accommodate standard fasteners, so as to eliminate any need for adapters or additional members or fasteners.

According to still another preferred aspect of the invention, the knife pin has an outer surface therearound, e.g., of a cylindrical or other suitable shape, to facilitate disassembly and service, and for allowing limited relative vertical movements of the knife head and knife arm if desired. Thus, for example, this relative vertical movement capability, and the capture or containment of the knife pin, provides an amount of self-adjustment in the relative positions of the knife arm and knife head, essentially to allow the knife head to lower as it and its supporting structure wears, to reduce possible occurrence of stress on components, binding, accelerated wear, power consumption, and the like. If used with a flexible sickle, the capability of the knife head to move vertically relative to the knife arm will allow and facilitate flexing of the sickle in the immediate vicinity of the knife head, which will also reduce binding, wear and power consumption.

According to another preferred aspect of the invention, the distal end of the knife arm has opposite sides that taper divergingly in the rearward direction from the distal end about the receptacle to the mounting end, to provide a streamlined shape for facilitating flow of plant material therepast and reducing plowing and other undesirable effects. This is preferably embodied in the knife arm having a V- or narrow U-shape about the receptacle that tapers sidewardly outwardly to about the width of the element of the driving mechanism to which the knife arm is attached.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings wherein a preferred embodiment of the invention is shown, inFIGS. 1 through 5, a conventional, well known agricultural cutting machine, which is a combine20, is shown including a header22. Header22is shown supported in the conventional, well-known manner on a forward end24of combine20, and is operable for cutting or severing crops such as, but not limited to, small grains such as wheat and soybeans, and inducting the severed crops into a feeder26for conveyance into combine20for threshing and cleaning, in the well known manner, as combine20moves forwardly over a field.

Header22includes a pan or floor28which is supported in desired proximity to the surface of the field during the harvesting operation, and an elongate, sidewardly extending sickle30along a forward edge portion32of floor28, sickle30being operable for severing the plants or crop for induction into header22, as will be explained. Header22additionally includes an elongate, sidewardly extending reel34disposed above sickle30and rotatable in a direction for facilitating induction of the severed plant material or crops into header22. Here, header22is configured as a draper type, having a system of elongate, flat, sidewardly moving draper belts36and38having upwardly facing surfaces disposed just rearwardly of forward edge portion32, operable in cooperation with reel34for conveying the severed plant material or crops toward an inlet opening of feeder26for induction into combine20, in the well-known manner.

Referring more particularly toFIG. 3, sickle30extends in a sideward direction along the width of floor28, between a first side edge portion40of the floor, and an opposite second side edge portion42. Sickle30includes an elongate, sidewardly extending first cutter bar assembly44, and an elongate, sidewardly extending second cutter bar assembly46extending in end to end relation to cutter bar assembly44, cutter bar assemblies44and46being supported in substantially longitudinally aligned relation adjacent to forward edge portion32of floor28.

Referring more particularly toFIGS. 4 and 5, cutter bar assemblies44and46each include a plurality of sidewardly facing aligned slots48through a sidewardly extending array of guards50which project forwardly from a stationary bar52at sidewardly spaced intervals therealong. Stationary bar52extends the length of sickle30just forwardly of forward edge portion32of floor28, and guards50are mounted to bar52with fasteners54. Bar52, in turn, is mounted to a frame56of header22adjacent to forward edge portion32by fasteners54, as best illustrated inFIG. 5. Each of cutter bar assemblies44and46supports an elongate knife assembly58for reciprocating longitudinal movement within slots48, each knife assembly58having a row of knife sections60including oppositely facing, angularly related knife edges which, in conjunction with adjacent guards50, effects a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards as the knife sections are reciprocatingly moved sidewardly, as denoted by arrow A inFIG. 4.

Knife assemblies58are reciprocatingly driven utilizing first and second sickle drives62A and62B. First and second sickle drives62A and62B are illustrated inFIGS. 3 and 4at a center location on header22between side edge portions40and42at the opposite ends of the header, although it should be noted that it is contemplated that sickle drives62A and62B could alternatively be utilized at other locations on a header, and that multiple sickle drives62could be used at multiple locations on a header. Sickle drives62A and62B are preferably located completely within or beneath floor28as best shown inFIG. 5, to reduce interruption of flow of cut plant material thereover and thereabout. Drives62A and62B can comprise a variety of mechanisms, such as, but not limited to, epicyclical drives that impart purely linear sideward motion, or pivoting sideward motion, to the knife head assemblies, as desired or required for a particular application. The disclosures and teachings of Priepke U.S. Pat. Nos. 7,810,304; 7,805,919; 7,730,709; 7,520,118; and 7,401,458, are hereby incorporated by reference herein in their entireties, as representative non-limiting examples of drives that can be utilized with the present invention.

Sickle drives62A and62B include drive elements102that project forwardly through slots104or other openings in or in the vicinity of forward edge portion32of floor28, for connection to the respective knife assemblies58, and which are moved in a side to side reciprocating motion by the respective drive, for effecting the cutting action. Header22includes knife heads64and knife arms66cooperatively arranged in knife head and arm assemblies68constructed and operable according to the present invention, connecting drives62A and62B in driving relation with respective knife assemblies58. As is evident from the location of knife head and arm assemblies68, they will be located directly in the path of the rearward flow of cut plant material over forward edge32and onto the upper surface of floor28during plant cutting operations. As a result, if assemblies68are large and/or obtrusive, they can have a plowing effect, causing the plant material to build up forwardly thereof, and/or be split or interrupted, so as to not flow smoothly onto the floor. It is therefore desired to minimize such flow disruptions.

Additionally, as noted above under the Background Art heading, from time to time, the knife sections60will be damaged, e.g., broken, chipped, become worn, or for other reasons require removal and replacement. Sometimes, this will be during plant cutting or harvesting, and thus in the field, and it will be desired to accomplish the removal and replacement as quickly as possible, with minimal removal/disassembly of components. It has also been found that a limited amount of relative vertical movement between the drive62A or62B and the knife assemblies58is desirable to facilitate free reciprocating movement of the knife assemblies, both to accommodate knife wear and flexing if so configured, as illustrated by the flexed cutter bar assemblies46and48, inFIG. 3A.

Referring also toFIGS. 6 through 13, knife head and arm assemblies68each comprise an elongate member70attached by an array of threaded fasteners72to an elongate structural beam74(FIGS. 5, 10, 11, and 12) underlying the respective knife head assembly58of the sickle cutter. Several of knife sections60of the respective knife assembly58are disposed between beam74and member70, so as to be clamped or captured by this attachment, while the other knife sections60of the knife assembly are mounted in the well known manner using additional fasteners72for direct attachment to beam74. Features of knife head64include controlled or limited vertical flexibility, which provides an ability to bend or flex to a limited extent with portions of a sickle attached thereto. This capability is preferably achieved by reducing the vertical height or extent of at least one longitudinal end76of member70relative to a middle or opposite end, as denoted by heights H1 and H2 inFIG. 12, resulting in a stepped shape, although it should be recognized that a tapered or other shape that imparts desired flexibility can alternatively be used. Fasteners72here comprise bolts which are inserted from below and extend upwardly through mating holes in beam74, knife sections60and knife head64, at the top of which they threadedly engage nuts78. On end76, nuts78are located on top of member70. On the thicker region, nuts78are located in upwardly facing sockets80recessed into the top surface of member70, such that the same length fasteners72can be used at both locations if desired. Fasteners72are arranged in a spaced apart longitudinally extending array, and are provided in sufficient number, e.g., eight or more, to provide secure attachment to beam74for clamping or capturing knife sections60, and for withstanding shear loads generated by the side to side cutting motion and reciprocating action, which will be longitudinal with respect to member70.

To provide added shear strength and a means to better align the holes of knife head64, knife sections60and beam74, knife head64preferably carries at least one and preferably two downwardly extending pins82positioned to be received in aligned holes in one or more of the knife sections and the beam, as shown inFIG. 12. Pins82are preferably disposed at a predetermined location corresponding or in close proximity to a knife pin84which is positioned for connection to knife arm66. Knife pin84is preferably mounted on the top surface of knife head64, by a threaded fastener86threadedly received in a threaded hole88in the upper surface of knife head64. When fastener86is tightened, its head is brought to bear against a shoulder90extending about the upper end of a hole92through the pin which receives fastener86. This arrangement allows removal of knife pin84from knife head64merely by removing fastener86, without accessing the underside of the knife head or removing it from the sickle.

Knife pin84is configured to be cooperatively received in a downwardly open receptacle94in a distal end96of knife arm66for connection to the respective drive62A or62B. Here, knife pin84has a smooth straight outer bearing surface98therearound which is preferably cylindrical shaped and sized to be matingly received in receptacle94for up and down movement therein, to facilitate relative up and down movement of knife head64and knife arm66, as denoted by arrows VM inFIG. 11.

Knife arm66has a mounting end100opposite distal end96, configured for attachment to a drive element102of drive62A or62B for reciprocating sideward movement therewith, as denoted by arrow A inFIG. 7(andFIG. 4). Recall here that the movement can be straight side to side or sideward pivoting movement, which will be a function of the type of drive used. Here also, it can be observed that the connection with drive element102includes a vertical key106which is cooperatively received in vertical keyway108in the drive element102to provide ease of alignment and strength under side to side shear loading conditions generated by the plant cutting action. Knife arm66is held in position on the end of element102by threaded fasteners110received in holes112in arm66and threadedly engaged with threaded holes114in drive element102, as illustrated inFIG. 8.

Addressing receptacle94of knife arm66, it is preferably bounded and defined by an inner bearing surface116which bounds and defines receptacle94, and which here is also cylindrical shaped, and sized for receiving knife pin84. The fit between inner surface116and outer surface98of the knife pin can be configured to allow relatively free vertical movement between knife arm66and knife pin84, but virtually no lateral play, which vertical movement will be limited to a maximum distance VM (FIG. 11) by the fixed vertical location of knife arm66by virtue of its attachment to element102of drive62A or62B, and the retention of knife head64, by virtue of attachment to knife assembly58and its containment in slot48of cutter bar44or46. Both the knife pin and receptacle should be sufficiently robust to handle the repetitive lateral forces that will be generated by prolonged cutting operation of the sickle. It should be noted however, that alternative shapes for outer surface98and bearing surface116can be used, such as but not limited to, rectangular, square, hexagonal, octagonal, and other polygons. An advantage of the cylindrical shape is that it also allows rotation of the knife head and knife assembly relative to the knife arm about a vertical axis through the knife pin, without tilting of the knife head and knife arm one relative to another.

Thus, for example, if a flexible sickle is employed, it will be able to smoothly flex up and down by virtue of freedom of knife pin84to move upwardly and downwardly within receptacle94, but the knife pin will be restrained against tilting or rocking movements, so as to reduce possible occurrences of binding and resultant increase in power consumption and wear. However, it should be noted that if some relative pivotal or rocking motion is desired or required in the horizontal plane, e.g., to accommodate a flexible cutter, a spherical or partial spherical type bearing or bushing can be employed.

To facilitate the ability of knife pin84and receptacle94to move freely upwardly and downwardly one relative to the other, and also rotate one relative to the other, knife arm66optionally includes an internal grease reservoir118configured for holding a quantity of grease for distribution within receptacle94, and a connecting grease fitting120usable for resupplying the grease as required. Alternatively, a grease or lubricant impregnated bushing or the like can be used in receptacle94for reducing friction at the interface between the knife pin and knife arm, and within a bearing at that location if used. The lower end and upper end of receptacle94is preferably enclosed to prevent entry of contaminants such as dust, dirt and the like into the interface between bearing surface116and outer surface98and into a bearing if used, a lower opening140being sealed with a conventional annular or ring seal142, and the upper end in a manner discussed below.

It is anticipated that with use, bearing surface116of a bearing that includes this surface, and/or the bearing itself, and/or the knife pin, will wear to such an extent as to require replacement. To facilitate replacement, bearing surface116of receptacle94comprises an inner peripheral surface of a removable bearing element122, which can comprise for instance a solid or impregnated sleeve or bushing, or a ball, needle, or spherical type bearing, press fit into a cavity124through lower opening140, and the upper end of receptacle94is shown enclosed by a removable plug126which is also usable for removing the bearing element122. The ability easily and quickly remove and replace bearing element122with tools available in the field is highly desired when harvesting and time is of the essence. In one preferred configuration, plug126is located in sealed abutment with a lower surface of a shoulder128extending at least partially about and defining an upper opening130(FIG. 13) of cavity124, above bearing element122and forming the desired sealed condition against entry of contaminants, moisture, etc. When removal and replacement of bearing element122is required, plug126can be pressed downwardly, using a press, or, if one is unavailable, e.g., service occurs in the field, suitable tools such as a hammer and a socket132or other suitable item of similar diameter to the bearing element and length, can be used to push or tap the plug downwardly through cavity124, and will also remove the ring seal142if used. In both instances, the downward movement of plug126will push bearing element122downwardly from cavity124through lower opening140. Replacement then entails simply replacing plug126in cavity124against shoulder128, and pressing or tapping the bearing element or a new one into position.

Here, it can be observed that cavity124and lower opening140have a first transverse extent or diameter, that is larger than that of upper opening130, and that plug126has a transverse extent or diameter that is marginally smaller than that of the cavity124and lower opening, to facilitate passage of the plug therethrough, but which prevents passage through upper opening130. Plug126can include a protuberance132extending upwardly therefrom and configured to sealably mate with and engage shoulder128to form the upper sealed condition. The protuberance132also strengthens plug126.

Here, plug126is illustrated as having a round disk shape, including protuberance132, although it should be understood that other shapes that provide the desired advantages can also be used. As non-limiting examples, protuberance132and shoulder128can have an oval, rectangular, star, or other polygonal shape, as desired or required for a particular application.

Thus, with the knife head and arm assembly of the invention, most of the knife sections60clamped to the sickle by knife head64can be removed and replaced by removal of just two fasteners78and nuts80, and knife pin84can be removed and replaced by removing knife arm66(requiring removing just two fasteners110) and one fastener86.

In another preferred configuration, as shown in various of the Figures, distal end96of knife arm66has opposite sides136and138that taper divergingly toward mounting end100. This imparts a streamlined shape to each of the knife arms for facilitating flow of plant material thereabout. This taper is preferably embodied in a V-shape or U-shape when viewed from above, extending about distal end96, and additionally serves to deflect the cut plant material to some extent away from the slots in forward end32of floor28of the header through which the driven elements of drives62A and62B extend.

Here, it should be noted that the knife arm assembly is illustrated and depicted with the cavity and receptacle for receiving the knife pin oriented so as to face downwardly. Although this is the preferred orientation, it should be understood that an upwardly facing orientation can alternatively be used, if desired or required for a particular application.

In light of all the foregoing, it should thus be apparent to those skilled in the art that there has been shown and described a novel knife arm assembly for connecting a sickle knife to a reciprocating drive mechanism. However, it should also be apparent that, within the principles and scope of the invention, many changes are possible and contemplated, including in the details, materials, and arrangements of parts which have been described and illustrated to explain the nature of the invention. Thus, while the foregoing description and discussion addresses certain preferred embodiments or elements of the invention, it should further be understood that concepts of the invention, as based upon the foregoing description and discussion, may be readily incorporated into or employed in other embodiments and constructions without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown, and all changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.