Patent Publication Number: US-2022232767-A1

Title: Lawn Care Vehicle Control Lever Adjustment Assembly

Description:
TECHNICAL FIELD 
     Example embodiments generally relate to lawn care vehicles and, more particularly, to such vehicles that use control levers, and a lever adjustment assembly that is configured to enable fine adjustments. 
     BACKGROUND 
     Lawn care tasks are commonly performed using various tools and/or machines that are configured for the performance of corresponding specific tasks. Certain tasks, like grass cutting, are typically performed by lawn mowers. Lawn mowers themselves may have many different configurations to support the needs and budgets of consumers. Walk-behind lawn mowers are typically compact, have comparatively small engines, and are relatively inexpensive. Meanwhile, at the other end of the spectrum, riding lawn mowers, such as lawn tractors, can be quite large. Riding lawn mowers can sometimes also be configured with various functional accessories (e.g., trailers, tillers, and/or the like) in addition to grass cutting components. Riding lawn mowers provide the convenience of a riding vehicle as well as a typically larger cutting deck as compared to a walk-behind model. 
     By their very nature, riding lawn mowers include steering assemblies that are used to direct the movement of the riding lawn mowers. The steering assemblies often take the familiar form of a steering wheel. However, handlebar assemblies have also been used in some cases. More recently, some mowers have been provided with very short (e.g., near zero) turning radiuses. Such mowers have employed separate steering levers that interface with the drive wheels on each respective side of the mower. 
     When these separate steering levers are employed, it is common for a drive wheel on each side of the vehicle to be controlled by a corresponding lever on the same side of the vehicle. The operator therefore sits in the seat of the vehicle (or sometimes stands at an operator station), and has the steering levers disposed in a convenient location for the operator to grasp. The operator then pulls the steering levers back, or pushes them forward, in order to control the direction and magnitude of drive power to be applied to each respective wheel. 
     Within the context described above, it is preferable for the operator to be enabled to adjust the position of the steering levers (sometimes called “sticks”) so that the neutral position of the sticks corresponds to a comfortable position for the operator. To make any necessary adjustments, conventional designs typically employ one of two different adjustment paradigms. First, there is a finite adjustment paradigm in which the steering levers can be adjusted (e.g., via a ratcheting or hole and pin style adjustment) between any of a plurality of different preconfigured locations. Each location corresponds to a separate tooth or hole position. For these designs, the preset locations of the adjustment points can make it very difficult to get the steering levers to line up properly. 
     A second adjustment paradigm may be referred to as an infinite slot adjustment paradigm. This design is aimed at completely eliminating the preconfigured locations, so that the steering levers can be adjusted to an infinite number of locations between the extreme ends of the adjustment range. Although offering a better chance of achieving good alignment of the steering levers in theory, this design tends to provide slip and therefore can move, even after tightening in a particular location. Moreover, imprints tend to be created within the adjustment slot, making minor adjustments very difficult to achieve. 
     Accordingly, it can be appreciated that there is room for improvement in relation to how steering levers are adjusted. 
     BRIEF SUMMARY OF SOME EXAMPLES 
     Some example embodiments of the present invention provide steering levers on a riding lawn care vehicle with an improved adjustment assembly that allows infinite adjustment, but does not suffer from the limitations described above. This arrangement, as will be discussed in greater detail below, tends to provide an improved operator experience during employment of the riding lawn care vehicle. 
     In one example embodiment, a riding lawn care vehicle is provided. The riding lawn care vehicle may include a frame to which at least a first drive wheel and a second drive wheel of the riding lawn care vehicle are attachable, a steering assembly and an adjustment assembly. The steering assembly may include a first steering lever and a second steering lever. The first and second steering levers may be operably coupled to the first and second drive wheels respectively to facilitate turning of the riding lawn care vehicle based on drive speed control of the first and second drive wheels responsive to positioning of the first and second steering levers along a first direction when the first and second steering levers are in an operating position. The adjustment assembly may provide for adjusting a position of one of the first or second steering levers. The adjustment assembly may include a sleeve operably coupled to one of the first steering lever or the second steering lever, a base portion operably coupled to the sleeve via a pivot coupling, and a rotatable adjuster. The pivot coupling may be configured to reposition the sleeve relative to the base portion along the forward and rearward directions responsive to operation of the rotatable adjuster to define non-discrete fixing relationships between the sleeve and the base portion along the forward and rearward directions. 
     In another example embodiment, an adjustment assembly for adjusting a position of one of a pair of steering levers of a riding lawn care vehicle that has first and second drive wheels is provided. The adjustment assembly may include a sleeve, a base portion and a rotatable adjuster. The steering levers may be operably coupled to respective ones of the first and second drive wheels to selectively control the riding lawn care vehicle based on drive speed control of the first and second drive wheels responsive to positioning of the steering levers along forward and rearward directions. The sleeve may be operably coupled to one of the steering levers and the base portion may be operably coupled to the sleeve via a pivot coupling. The pivot coupling is configured to reposition the sleeve relative to the base portion along the forward and rearward directions responsive to operation of the rotatable adjuster to define non-discrete fixing relationships between the sleeve and the base portion along the forward and rearward directions. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Having thus described some embodiments of the present invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1A  illustrates a perspective view of a riding lawn care vehicle according to an example embodiment; 
         FIG. 1B  illustrates a top view of the riding lawn care vehicle according to an example embodiment; 
         FIG. 2  illustrates a perspective view of a steering assembly with steering levers positioned to be pulled back for rearward propulsion according to an example embodiment; 
         FIG. 3  illustrates a block diagram of some steering assembly components according to an example embodiment; 
         FIG. 4  illustrates a block diagram of a lever mount of a steering assembly in accordance with an example embodiment; 
         FIG. 5  illustrates a perspective view of an adjustment assembly in accordance with an example embodiment; 
         FIG. 6  illustrates a perspective view of the other side of the adjustment assembly of  FIG. 5  in accordance with an example embodiment; 
         FIG. 7  is a perspective view of the adjustment assembly in greater detail in accordance with an example embodiment; 
         FIG. 8  illustrates a perspective view of the other side of the adjustment assembly of  FIG. 7  in accordance with an example embodiment; 
         FIG. 9  is a cross section view of the adjustment assembly with a sectioning plane bisecting a pivot block of the adjustment assembly along a longitudinal axis of the pivot block in accordance with an example embodiment; and 
         FIG. 10  is a cross section view of the adjustment assembly with a sectioning plane bisecting an adjustment channel along a longitudinal axis of the adjustment channel in accordance with an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability, or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term “or” is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, the phrase “operable coupling” and variants thereof should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection of components that are operably coupled to each other. 
     Some example embodiments may improve the ability of an operator to precisely set or adjust (including fine adjustment) the position of the steering levers of lawn care vehicles such as, for example, zero-turning radius lawn mowers. This further enables the operator to get exact alignment between the right and left steering levers at the neutral position. In this regard, some example embodiments may provide a steering assembly that employs a rotatable adjuster (e.g., a lead screw) to finely set the adjustment of the control levers. A pivot block or similar structure may be provided in a center portion of a connection part of the lever mount (e.g., a tube end of a socket to which the tube can be affixed) to enable the rotatable adjuster to be turned for positioning of the steering levers. The rotatable adjuster may pass through an adjustment channel and the pivot block, and will be allowed to move up and down as the handle adjustment sweeps on an arc around the adjustment pivot location. The rotatable adjuster can employ a knob end, or some other relatively easy-to-grip structure, so that the adjustments can be made completely without tools. However, if tool use is desired, the rotatable adjuster could instead be configured to interface with a tool (e.g., having a hex head, or a slot arrangement that mates with a screw driver or other tool. Such a design may further enable the user to adjust the position of the control levers without having to loosen and/or tighten a fastener at the pivot joint of the control levers. Moreover, the design could also be amenable to modification by adding motorized or electrified operation. 
       FIG. 1 , which includes  FIGS. 1A and 1B , illustrates a riding lawn care vehicle  10  according to an example embodiment.  FIG. 1A  illustrates a perspective view of the riding lawn care vehicle  10 , and  FIG. 1B  illustrates a top view of the riding lawn care vehicle  10  according to an example embodiment. In some embodiments, the riding lawn care vehicle  10  may include a seat  20  that may be disposed at a center, rear, or front portion of the riding lawn care vehicle  10 . The riding lawn care vehicle  10  may also include a steering assembly  30  (e.g., a set of steering levers or the like) functionally connected to wheels  31  and/or  32  of the riding lawn care vehicle  10  to allow the operator to steer the riding lawn care vehicle  10 . 
       FIG. 2  illustrates a perspective view of a steering assembly with steering levers positioned to be pulled back for rearward propulsion according to an example embodiment. Referring to  FIGS. 1 and 2 , the operator may sit on the seat  20 , which may be disposed to the rear of the steering assembly  30  to provide input for steering of the riding lawn care vehicle  10  via the steering assembly  30 . However, some models may be stand-up models that eliminate the seat  20 . If the seat  20  is eliminated, the operator may stand at an operator station proximate to the steering assembly  30 . In an example embodiment, the steering assembly  30  may include separately operable steering levers  34  (which may be alternatively referred to as “control sticks,” “control levers,” or simply “sticks”) shown specifically in  FIG. 1B  and  FIG. 2 . 
     The riding lawn care vehicle  10  may also include a cutting deck  40  having at least one cutting blade (e.g., three cutting blades) mounted therein. The cutting deck  40  may be positioned substantially rearward of a pair of front wheels  31  and substantially forward of a pair of rear wheels  32  in a position to enable the operator to cut grass using the cutting blade(s) when the cutting blade(s) are rotated below the cutting deck  40  when the cutting deck  40  is in a cutting position. However, in some alternative examples, the cutting deck  40  may be positioned in front of the front wheels  31 . In some embodiments, a footrest  42  may also be positioned above the cutting deck  40  forward of the seat  20  to enable the operator to rest his or her feet thereon while seated in the seat  20 . In embodiments that do not include the seat  20 , the footrest  42  may form the operator station from which a standing operator controls the riding lawn care vehicle  10 . When operating to cut grass, the grass clippings may be captured by a collection system, mulched, or expelled from the cutting deck  40  via either a side discharge or a rear discharge. 
     In the pictured example embodiment, an engine  50  of the riding lawn care vehicle  10  is disposed to the rear of a seated operator. However, in other example embodiments, the engine  50  could be in different positions such as in front of or below the operator. As shown in  FIG. 1 , the engine  50  may be operably coupled to one or more of the wheels  31  and/or  32  to provide drive power for the riding lawn care vehicle  10 . The engine  50 , the steering assembly  30 , the cutting deck  40 , the seat  20 , and other components of the riding lawn care vehicle  10  may be operably connected (directly or indirectly) to a frame  60  of the riding lawn care vehicle  10 . The frame  60  may be a rigid structure configured to provide support, connectivity, and/or interoperability functions for various ones of the components of the riding lawn care vehicle  10 . 
     In some example embodiments, the steering assembly  30  may be embodied as an assembly of metallic and/or other rigid components that may be welded, bolted, and/or otherwise attached to each other and operably coupled to the wheels of the riding lawn care vehicle  10  to which steering inputs are provided (e.g., rear wheels  32 ). For example, the steering assembly  30  may include or otherwise be coupled with hydraulic motors that independently power one or more drive wheels (e.g., rear wheels  32 ) on each respective side of the riding lawn care vehicle  10 . The steering levers  34  may be operable to move forward (i.e., in a direction opposite arrow  68  in  FIG. 2 ) and rearward (i.e., in the direction shown by arrow  68  in  FIG. 2 ) while in the inboard position (shown in both  FIGS. 1 and 2 ). 
     When a steering lever  34  is pushed forward (e.g., away from the operator an opposite the direction of arrow  68 ), the corresponding hydraulic motor may drive the corresponding wheel forward. When a steering lever  34  is pulled rearward (e.g., toward the operator as shown by the direction of arrows  68  in  FIG. 2 ), the corresponding hydraulic motor may drive the corresponding wheel backward. Thus, when both steering levers  34  are pushed forward the same amount, the riding lawn care vehicle  10  travels forward in substantially a straight line because approximately the same amount of forward drive input is provided to each drive wheel. When both steering levers  34  are pulled back the same amount, the riding lawn care vehicle  10  travels backward (e.g., rearward) in substantially a straight line because approximately the same amount of rearward drive input is provided to each drive wheel. When one steering lever  34  is pushed forward and the other steering lever  34  is pulled back, the riding lawn care vehicle  10  begins to turn in a circle and/or spin. Steering right and left may be accomplished by providing uneven amounts of input to the steering levers  34 . Other steering control systems may be employed in some alternative embodiments such as, for example, electric motor control. 
     Although the steering levers  34  are generally moved forward (i.e., opposite the direction of the arrows  68  shown in  FIG. 2 ) or backward (i.e., in the direction of the arrows  68  shown in  FIG. 2 ) in any desirable combination while they are in the operating positions shown in  FIGS. 1 and 2 , it should be appreciated that the steering levers  34  may also be moved to an outboard position (e.g., in a non-operational state) by moving the steering levers  34  outwardly in the direction shown by arrows  70  in  FIG. 1B . In this regard, although the steering levers  34  are shown in the inboard (or operational) position in  FIGS. 1 and 2 , the steering levers  34  may be moved in the direction of arrows  70  (i.e., outboard) relative to their inboard position and into a non-operational position. In some cases, each of the steering levers  34  may be operably coupled to respective lever mounts  80  that may pivot to enable the steering levers  34  to move outwardly (e.g., to the outboard position) or inwardly (e.g., to an inboard and/or operating position). In some embodiments, when at least one (and sometimes both) of the steering levers  34  is pivoted outwardly, brakes may be applied and the operator may easily mount or dismount the riding lawn care vehicle  10  and sit in or leave the seat  20 . 
     In some conventional riding lawn care vehicles, a brake lever separate and distinct from the steering assembly is provided to interface with the brake assembly of the vehicle. In others, as noted above, the steering levers  34  are moved outwardly to the outboard position, and the outward movement to the outboard position is used to operate a let of linkages or other operable coupling to set the brake assembly. 
       FIG. 3  illustrates a block diagram of some steering and braking components of an example embodiment. As shown in  FIG. 3 , each one of the steering levers  34  may be operably coupled to a corresponding one of the lever mounts  80 . The lever mounts  80  may be operably coupled to corresponding hydraulic motors  100  that power respective ones of the drive wheels (e.g., the rear wheels  32 ). A brake system including a brake assembly  110  is also provided in which, for example, the brake assembly  110  is activated via outboard movement of the steering levers  34 . To accomplish this, a mechanical brake linkage assembly  120  may be provided to operably coupled each respective steering lever  34  and/or lever mount  80  to the brake assembly  110  to activate brakes (electrically or mechanically) on the rear wheels  32  based on moving a position of the steering lever  34  and/or lever mount  80  to the outboard position. 
     As shown in  FIG. 3 , the mechanical brake linkage assembly  120  is provided to operably couple the lever mounts  80  to the brake assembly  110 . In some cases, the mechanical brake linkage assembly  120  can be split into right side and left side linkages that are independent of each other. However, in other cases, the right and left side linkages may also be tied together so that they operate in tandem, or movement of one steering lever  34  carries the other. In either case, if the lever mount  80  on either side may be pivoted to the outboard position, the mechanical brake linkage assembly  120  may operate to activate the brake assembly  110  so that brakes are applied at the rear wheels  32 . 
     The lever mounts  80  may further include (or be operably coupled to) an adjustment assembly  200  of an example embodiment. The adjustment assembly  200  may provide for infinite adjustment of the neutral position of the steering levers  34  (i.e., the position when no force is applied thereto in either the forward or rearward direction) between the opposing limits of a range of adjustable setpoints for the neutral position. Moreover, the adjustment assembly  200  may be configured to enable such adjustment without need for tools, and in a way that permits fine adjustments of both steering levers  34  so that the neutral positions thereof are aligned or matching. 
     The adjustment assembly  200  could take a number of different forms. One such form is shown in the examples of  FIGS. 4-10 . In this regard,  FIG. 4  illustrates a perspective view of the adjustment assembly  200  along with other components of the lever mount  80  in accordance with an example embodiment.  FIGS. 5 and 6  illustrate opposing perspective views showing the adjustment assembly  200  in greater detail. Similarly,  FIGS. 7 and 8  show opposing perspective views of the adjustment assembly  200  in isolation and in still greater detail. Meanwhile,  FIGS. 9 and 10  are each cross section views of the adjustment assembly  200  with the sectioning plane of  FIG. 9  bisecting a pivot block (along its longitudinal axis) of the adjustment assembly  200  and  FIG. 10  bisecting an adjustment channel (again, along its longitudinal axis) of the adjustment assembly  200 . 
     Referring now to  FIGS. 4-10 , the adjustment assembly  200  comprises a sleeve  210  that is operably coupled to a base portion  212  via a pivot coupling  214 . Movement of the sleeve  210  relative to the base portion  212 , and therefore adjustment of the pivot coupling  214 , may be accomplished by rotation of a rotatable adjuster  220 . The rotatable adjuster  220  comprises a threaded member (e.g., lead screw  222 ) that is operable via turning of a knob  224 . A retaining nut  226  is provided at a distal end of the lead screw  222  to retain the rotatable adjuster  220  on the base portion  212 . 
     The base portion  212  of the adjustment assembly  200  is operably coupled to a mount base  190  of the lever mount  80  via inboard/outboard pivot  192 . As noted above, the steering levers  34  may be rotated outboard (shown by arrow  194 ) for applying a parking brake and/or for facilitating exit from the seat  20  for the operator. The steering levers  34  may also (when in the inboard position shown in  FIG. 4 ) be pulled rearward or forward as shown by double arrow  196 . When pivoted either forward or rearward, the lever mount  80  may also be biased to return back to a neutral position. Meanwhile, the adjustment assembly  200  may be used to locate the steering levers  34  in a desirable position for the user by enabling fine adjustment in the forward or rearward directions. 
     The base portion  212  may include a back plate  216 , and opposing arms  218  that extend perpendicularly away from the back plate  216  and face each other to define an adjustment space therebetween. The pivot coupling  214  may be formed by passing a sleeve base  230  formed at a proximal end of the sleeve  210  (relative to the pivot coupling  214 ) between the arms  218  and operably coupling the sleeve base  230  to the back plate  216  at a pivot point  232 . The pivot point  232  may be formed via a screw and nut combination, where the screw and nut combination rotatably retain the sleeve base  230  to the back plate  216  of the base portion  212  at the pivot point  232 . 
     The back plate  216  may also include a movement limiting slot  234  formed spaced apart from the pivot point  232 . A limit screw  236  may be operably coupled to a pivot block  240  of the adjustment assembly  200 , and may be passed through the movement limiting slot  234 . As described in greater detail below, the adjustment assembly  200  may be operated to adjust a position of the sleeve  210  about the pivot point  232  by operation of the rotatable adjuster  220 . By doing so, the sleeve  210  may move from a first end of an operable range (where the limit screw  236  is at one end of the movement limiting slot  234  and the sleeve base  230  is closest to one of the arms  218 ) to a second end of the operable range (where the limit screw  236  is at the opposite end of the movement limiting slot  234  and the sleeve base  230  is closest to the other one of the arms  218 ). As can be appreciated from the description above, the pivot coupling  214  may be defined at least in part by the pivot point  232 , the movement limiting slot  234  and the limit screw  236 , along with the rotatable adjuster  220  and the interaction between the lead screw  222  thereof and the pivot block  240 , which carries the sleeve base  230  along the lead screw  222  to reposition the sleeve base  230  relative to the base portion  212 . 
     The pivot block  240  may be retained within the base portion  230  such that the pivot block  240  rotates or pivots therein responsive to operation of the rotatable adjuster  220 . The pivot block  240  may include a threaded adjustment channel  250  passing therethrough. The pivot block  240  may be substantially cylindrical (or a hollow cylinder) with an axis that is coaxial with the limit screw  236 . The axis of the pivot block  240  may be substantially perpendicular to the axis of the sleeve  210 . The pivot channel  230  may extend substantially perpendicularly through the pivot block  240  relative to the axis of the pivot block  240  as well. The axis of the pivot channel  230  may also be substantially perpendicular to the axis of the sleeve  210 . The pivot block  240  may be enabled to rotate or pivot within the base portion  230  as the rotatable adjuster  220  is turned or rotated. However, due to the threaded engagement between the lead screw  222  and adjustment channel  250 , the rotation of the rotatable adjuster  220  will cause the pivot block  240  to be carried along a length of the lead screw  222  and thereby adjust the orientation of the sleeve  210  (and more particularly the sleeve base  230 ) relative to the base  212  (by pivoting the sleeve  210  about the pivot point  232 ). 
     In an example embodiment, rotation of the knob  224  in a first direction (shown by arrow  260  in  FIGS. 5-7 ) will cause corresponding rotation of the lead screw  222  to draw the pivot block  240  toward the knob  224  in a direction shown by arrow  262  in  FIGS. 5-7 . Meanwhile, rotation of the knob  224  in a second direction (shown by arrow  264  in  FIGS. 5-7 ) will cause corresponding rotation of the lead screw  222  to push the pivot block  240  away from the knob  224  in a direction shown by arrow  266  in  FIGS. 5-7 . The corresponding pivoting of the sleeve  210  will carry the corresponding steering lever  34  (which is inserted into the sleeve  210 ) accordingly either forward or rearward. The operator can therefore adjust the neutral position of each of the steering levers  34  using the corresponding adjustment assembly  200  on its side and obtain a comfortable setting (while also matching right and left sides exactly). Moreover, as noted above, the knob  224  could be replaced by an electric motor in some cases, and the electric motor may reposition the lead screw  222  by rotation in the directions shown in  FIGS. 5-7 . 
     Accordingly, some example embodiments may provide an adjustment assembly that may enable movement of a steering lever in a reverse (or forward) direction to alter a neutral position of the steering lever. In particular, some examples may employ one instance on each lever for a riding lawn care vehicle. The riding lawn care vehicle may include a frame to which at least a first drive wheel and a second drive wheel of the riding lawn care vehicle are attachable, a steering assembly and an adjustment assembly. The steering assembly may include a first steering lever and a second steering lever. The first and second steering levers may be operably coupled to the first and second drive wheels respectively to facilitate turning of the riding lawn care vehicle based on drive speed control of the first and second drive wheels responsive to positioning of the first and second steering levers along a first direction when the first and second steering levers are in an operating position. The adjustment assembly may provide for adjusting a position of one of the first or second steering levers. The adjustment assembly may include a sleeve operably coupled to one of the first steering lever or the second steering lever, a base portion operably coupled to the sleeve via a pivot coupling, and a rotatable adjuster. The pivot coupling may be configured to reposition the sleeve relative to the base portion along the forward and rearward directions responsive to operation of the rotatable adjuster to define non-discrete fixing relationships between the sleeve and the base portion along the forward and rearward directions. 
     The riding lawn care vehicle (or adjustment assembly) of some embodiments may include additional, optional features, and/or the features described above may be modified or augmented. Some examples of modifications, optional features and augmentations are described below. It should be appreciated that the modifications, optional features and augmentations listed below may each be added alone, or they may be added cumulatively in any desirable combination. For example, in some embodiments, the pivot coupling may include a pivot block disposed in a sleeve base of the sleeve. The pivot block may be pivotable with respect to the sleeve base responsive to operation of the rotatable adjuster. In an example embodiment, the pivot coupling may include a pivot point defining a point at which the sleeve pivots with respect to the base portion. The pivot coupling may include a movement limiting slot formed in the base portion, and a limit screw operably coupled to the pivot block. The limit screw may pass through the movement limiting slot to limit a range of movement of the sleeve base relative to the base portion. In some cases, the movement limiting slot may be formed in the base portion spaced apart from the pivot point. An axis of the pivot point may be substantially perpendicular to a longitudinal axis of the sleeve. In an example embodiment, the pivot block may define a threaded adjustment channel passing therethrough substantially perpendicular to an axis of the pivot block. In some cases, the rotatable adjuster comprises a knob and a lead screw, the lead screw may be in threaded engagement with the adjustment channel such that rotation of the rotatable adjuster carries the pivot block along the lead screw thereby adjusting a position of the sleeve base relative to the base portion. In an example embodiment, the base portion may include a back plate and arms extending substantially perpendicularly away from the back plate on opposing lateral sides of the back plate. The lead screw may pass through the arms, and adjusting the position of the sleeve base relative to the base portion may move the sleeve base closer to one of the arms and farther away from the other one of the arms. In some cases, the pivot coupling may include a pivot block disposed in a sleeve base of the sleeve, and the pivot block may have an axis about which the pivot block rotates or pivots within the sleeve base. The axis may be substantially perpendicular to a direction of lateral movement of the pivot block responsive to rotation of the rotatable adjuster. In an example embodiment, the rotatable adjuster may be adjustable by an operator without tools. In some cases, the adjustment assembly may include a first adjustment assembly for adjusting a position of the first steering lever, and a second adjustment assembly for adjusting a position of the second steering lever. In an example embodiment, the riding lawn care vehicle may be a zero-turn radius lawn mower. 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits, or solutions to problems are described herein, it should be appreciated that such advantages, benefits, and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits, or solutions described herein should not be thought of as being critical, required, or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.