Embodiments of the present disclosure relate generally to turf maintenance vehicles and, more particularly, to a control system operable to control propulsion of the vehicle.
Self-propelled mid-size mowers (e.g., those having a deck cutting width of approximately 36-60 inches) are commonly used by homeowners and landscape professionals alike. While such mowers may be configured for a riding (including ride-on and ride-behind) or a walk-behind operator, walk-behind mowers have proven popular for many users. For example, walk-behind mowers have proven particularly adept at mowing large lawns with numerous obstacles (e.g., trees, shrubs, flowerbeds, and the like) which necessitate intricate trimming maneuvers, or when mowing lawns which may otherwise be ill-suited to high-speed riding mowers. Moreover, walk-behind mowers are often used when mowing areas with steep slopes.
One type of control system common among mid-size mowers uses two rearwardly extending, horizontal handles each equipped with a scissors-type lever. Each lever operatively controls one of the mower's drive wheels. Where the levers are configured as “normally engaged,” actuating (e.g., squeezing) one of the drive levers causes a proportional slowing of the corresponding drive wheel, permitting the mower to turn about that wheel. Alternatively, the levers may be “normally disengaged” such that actuating (e.g., squeezing) one of the drive levers causes a proportional increase in the rotational speed of the corresponding drive wheel. By independently controlling the drive wheels, forward and reverse speed changes, as well as left and right turning, may be accomplished.
While scissors-type lever control systems are more than adequate for their intended purpose, drawbacks remain. For instance, scissors-type levers, in general, may provide limited mechanical advantage in overcoming lever tension. Accordingly, when cutting a lawn with many trees, shrubs, or other obstacles that necessitate numerous turns, discomfort in the hands, wrists, and arms may occur. Scissors-type lever control systems may also be susceptible to variation in lever tension over the lever travel. Still further, depending on the position of each lever within its throw, the operator may not be able to grasp the respective lever with all fingers.
Other types of control systems are also known, for example, U.S. Pat. No. 5,511,367 to Powers et al. and U.S. Pat. No. 5,809,755 to Velke et al. disclose control systems having a generally transverse hand position. While addressing some of the above-identified problems, other issues with hand position and/or control actuation potentially remain. Further, U.S. Pat. No. 6,557,331 to Busboom et al. discloses a control system having control levers that pivot about an axis parallel to the corresponding hand grip, but the hand grips are positioned to extend upwards and towards the center of the mower, keeping the operator's arms in a bent and/or flexed position.
Embodiments described herein may provide a turf maintenance vehicle control system, and associated methods, that may simplify vehicle operation. For example, in one embodiment, an operator control system for a turf maintenance vehicle may include a handle assembly, a first control lever, and a second control lever. The handle assembly may include a first hand grip defining a first grip axis and a second hand grip defining a second grip axis. Each of the first and second hand grips may extend between an attached end and a free end. The free end of each of the first and second hand grips may be located aft of the attached end of each of the first and second hand grips, respectively. The first control lever may be associated with the first hand grip and may be pivotable about a first pivot axis. The first pivot axis may be parallel to the first grip axis. The second control lever may be associated with the second hand grip and may be pivotable about a second pivot axis. The second pivot axis may be parallel to the second grip axis.
In another embodiment, an operator control system for a turf maintenance vehicle may include a handle assembly, a first control lever, a second control lever, and a first locking device. The handle assembly may include a first hand grip defining a first grip axis and a second hand grip defining a second grip axis. Each of the first and second hand grips may extend at an angle of between 20 and 35 degrees from a horizontal plane when the turf maintenance vehicle is in an operating configuration. The first control lever may be associated with the first hand grip and may be pivotable about a first pivot axis. The first pivot axis may be parallel to the first grip axis. The second control lever may be associated with the second hand grip and may be pivotable about a second pivot axis. The second pivot axis may be parallel to the second grip axis. The first locking device may be pivotally coupled to the first hand grip about a lock pivot axis and adapted to position the first control lever in at least a first position. Either the first locking device or the first control lever may define a first notch and the other of the first locking device and the first control lever may include a protrusion. The protrusion may be positioned in the first notch when in the first position.
In yet another embodiment, a turf maintenance vehicle may include a chassis supported upon a ground surface by a plurality of ground-engaging members, a prime mover supported by the chassis, and an operator control system supported by the chassis and operably connected to the prime mover. The operator control system may be located aft of the prime mover and may include a handle assembly, a first control lever, and a second control lever. The handle assembly may include a first hand grip defining a first grip axis and a second hand grip defining a second grip axis. Each of the first and second hand grips may extend between an attached end and a free end. The free end of each of the first and second hand grips may be located aft of the attached end of each of the first and second hand grips, respectively. The first control lever may be associated with the first hand grip and may be pivotable about a first pivot axis. The first pivot axis may be parallel to the first grip axis. The second control lever may be associated with the second hand grip and may be pivotable about a second pivot axis. The second pivot axis may be parallel to the second grip axis.
The above summary is not intended to describe each embodiment or every implementation. Rather, a more complete understanding of illustrative embodiments will become apparent and appreciated by reference to the following Detailed Description of Exemplary Embodiments and Claims in view of the accompanying figures of the drawing.
Exemplary embodiments will be further described with reference to the figures of the drawing, wherein:
The figures are rendered primarily for clarity and, as a result, are not necessarily drawn to scale. Moreover, various structure/components, including but not limited to fasteners, electrical components (wiring, cables, etc.), and the like, may be shown diagrammatically or removed from some or all of the views to better illustrate aspects of the depicted embodiments, or where inclusion of such structure/components is not necessary to an understanding of the various exemplary embodiments described herein. The lack of illustration/description of such structure/components in a particular figure is, however, not to be interpreted as limiting the scope of the various embodiments in any way. Still further, “Figure x” and “FIG. x” may be used interchangeably herein to refer to the figure numbered “x.”
In the following detailed description of illustrative embodiments, reference is made to the accompanying figures of the drawing which form a part hereof. It is to be understood that other embodiments, which may not be described and/or illustrated herein, are certainly contemplated. Unless otherwise indicated, all numbers expressing quantities, and all terms expressing direction/orientation (e.g., vertical, horizontal, parallel, perpendicular, etc.) in the specification and claims are to be understood as being modified in all instances by the term “about.”
Generally speaking, embodiments of the present disclosure may be directed to control systems for controlling various aspects of a power turf maintenance vehicle (e.g., a walk-behind lawn mower). The control system may include control levers on left and right sides of the vehicle that operatively control rotational speed and direction of left and right drive wheels, respectively. Each of the left and right control levers may be ergonomically positioned for comfortable use by a walk-behind (or ride-behind, ride-on, etc.) operator. For example, each control lever may move, relative to a corresponding hand grip, such that an entire length of the control lever is parallel with the hand grip throughout the entire range of control lever movement. In other words, when the hand/fingers of the operator are used to actuate the control lever, each finger gripping the control lever travels the same distance because the control lever remains parallel with the hand grip.
Additionally, the control system may include a locking device corresponding to each of the left and right control levers. Each locking device may be used to temporarily lock its corresponding control lever into one of a plurality of positions. For example, the control levers may each actuate between: a full forward position (e.g., when the control lever is farthest from the hand grip) in which the corresponding drive wheel is powered to propel the vehicle in a forward direction (i.e., “normally engaged”); and a full reverse position (e.g., when the control lever is closest to the hand grip) in which the corresponding drive wheel is powered to propel the vehicle in a reverse direction. In one or more embodiments, the locking devices (or any other devices, components, structures, etc.) may restrict the motion of the control lever from moving past the full forward position (e.g., by restricting the distance the control lever may travel away from the hand grip) and the hand grip and/or locking device may restrict the motion of the control lever at the full reverse position (e.g., contacting the hand grip and/or locking device). Between the full forward position and the full reverse position, the locking device may lock the corresponding control lever into a neutral position in which no output is provided at the corresponding drive wheel. Furthermore, the control levers operate independently and, similarly, each corresponding locking device may be used independent of the other.
With reference to the figures of the drawing, wherein like reference numerals designate like parts and assemblies throughout the several views,
It is noted that the term “comprises” (and variations thereof) does not have a limiting meaning where this term appears in the accompanying description and claims. Further, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably herein. Moreover, relative terms such as “left,” “right,” “front,” “fore,” “forward,” “rear,” “aft,” “rearward,” “top,” “bottom,” “side,” “upper,” “lower,” “above,” “below,” “horizontal,” “vertical,” and the like may be used herein and, if so, are from the perspective of one operating the mower 100 while the mower is in an operating configuration, e.g., while the mower 100 is positioned such that wheels 106 and 108 rest upon a generally horizontal ground surface 103 as shown in
Still further, the suffixes “a” and “b” may be used throughout this description to denote various left- and right-side parts/features, respectively. However, in most pertinent respects, the parts/features denoted with “a” and “b” suffixes are substantially identical to, or mirror images of, one another. It is understood that, unless otherwise noted, the description of an individual part/feature (e.g., part/feature identified with an “a” suffix) also applies to the opposing part/feature (e.g., part/feature identified with a “b” suffix). Similarly, the description of a part/feature identified with no suffix may apply, unless noted otherwise, to both the corresponding left and right part/feature.
As shown in
An implement adapted to perform a maintenance task, e.g., a lawn mower cutting deck 114, may be connected to, or otherwise carried by, the chassis 102 of the mower 100, e.g., generally between the drive wheels 106 and the caster wheels 108. The cutting deck 114 may include a deck housing 117 that defines a downwardly-opening cutting chamber (not shown). The cutting chamber may partially surround one or more rotatable cutting blades (also not shown), each attached to a blade spindle assembly as is known in the art. Of course, other cutting decks (e.g., out-front decks, towed decks, reel units, etc.), as well as other implements, are contemplated within the scope of this disclosure. During operation, power is selectively delivered to the cutting deck 114 (e.g., to the spindle assemblies) and the drive wheels 106, whereby the cutting blades rotate at a speed sufficient to sever grass and other vegetation as the deck passes over the ground surface 103. Typically, the cutting deck 114 includes an operator-selectable height-of-cut control system to allow deck height adjustment relative to the ground surface 103.
With this general overview, an embodiment of an exemplary control system 200 will now be described. As shown in
While not wishing to be bound to any specific configuration, the control panel 201 may include operator-selectable controls (e.g., switches) configured to provide inputs to the control system 200. For example, the control panel 201 may include a key/ignition switch 208 for starting the engine 104 or otherwise activating the vehicle's electrical system. Moreover, the control panel may include a drive wheel speed lever 202 (e.g., to control the maximum speed of each drive wheel at the full forward position) and a throttle 204 (e.g., to control engine speed to the cutting blades of the mower). Further, the mower 100 may include a parking brake handle, e.g., to selectively activate a brake when the vehicle is parked. Other controls not central to this disclosure may also be provided.
As shown in
Each of the first and second hand grips 220 (e.g., grip axes 221) may be positioned in any suitable way such that an operator may grasp the hand grip 220 when the operator's arms are extending downwards (e.g., generally vertical). In other words, the hand grips 220 may extend rearwardly, outwardly, and downwardly when the mower 100 is in an operating configuration (e.g., upright on the ground surface 103 as illustrated in
This position or orientation of the hand grips 220 may provide an ergonomic, comfortable position for the operator's arms and hands when grasping the hand grips 220 and operating the mower 100. For example, the arms of the operator may be positioned in a more relaxed or generally extended position (e.g., a generally vertical orientation). Furthermore, the position or orientation of the hand grips 220 may allow the operator to easily apply his or her bodyweight as a downward force to lift or “float” the cutting deck 114 of the mower 100. For example, a high amount of force may be applied to the hand grips 220 because the operator is in a centered position over the grip axes 221 such that the operator may be able to easily apply a downward force.
Further, each of the first and second hand grips 220a, 220b may be described as extending between an attached end (222a, 222b, respectively) and a free end (224a, 224b, respectively). The attached end 222 of each hand grip 220 may be coupled to (or be formed integral with) a handle tube 116 (e.g., 116a and 116b) connected to, and extending rearwardly and upwardly from, the frame 102. Accordingly, each handle tube 116 connects its respective hand grip 220 to the frame 102.
In one or more embodiments, the free end 224 of each of the hand grips 220 may be located aft of (e.g., behind) the attached end 222. Positioning the free end 224 behind the attached end 222 may help to prevent the hand grips 220 from inadvertent contact, e.g., becoming caught when the mower 100 is traveling in a forward direction. Each of the first and second hand grips 220a, 220b may also be described as extending rearwardly away from each other and away from a longitudinal axis 101 (e.g., as shown in
The control system 200 may also include a first control lever 230a (e.g., associated with the first hand grip 220a) and a second control lever 230b (e.g., associated with the second hand grip 220b). The control levers 230 may be configured to control power delivery (i.e., speed and direction) to the corresponding drive wheels 106. For example, the first control lever 230a may control power delivery to the left drive wheel 106a and the second control lever 230b may control power delivery to the right drive wheel 106b. The first and second control levers 230a, 230b may be operably coupled, e.g., to separate hydraulic pumps, to independently and proportionally vary a velocity of the drive wheels 106a, 106b, respectively. Further, the control levers 230 may be operable to independently control a rotational direction of their respective drive wheels 106 via manipulation of the mower's drive system as is known in the art. Specifically, the control lever 230 may be manipulated (e.g., pivoted about an axis) between a full forward position, a neutral position, and a full reverse position. As each control lever 230 moves between these positions, the drive system may proportionally command the respective drive wheel 106 to rotate at a speed (and direction) corresponding to the position of the particular control lever 230.
Each of the first and second control levers 230a, 230b may include a connection portion 234a, 234b pivotally coupled to a portion of the mower 100 and a handle portion 236a, 236b extending therefrom (e.g., as shown in
The handle portions 236a, 236b of the first and second control levers 230a, 230b may also define (e.g., extend along) first and second lever axes 231a, 231b, respectively. Furthermore, in some embodiments, the first lever axis 231a may be parallel to the first grip axis 221a and the second lever axis 231b may be parallel to the second grip axis 221b. In other words, the first control lever 230a (e.g., the handle portion 236a) may extend parallel to the first hand grip 220a and the second control lever 230b (e.g., the handle portion 236b) may extend parallel to the second hand grip 220b. Because of the parallel orientation of the corresponding grip axes 221, pivot axes 233, and lever axes 231, the control lever 230 may remain generally parallel to the respective hand grip 220 as the control lever 230 is actuated relative to the hand grip 220. As a result, the force required to manipulate each control lever 230 (e.g., the lever tension) may be uniform along the control lever 230 throughout the travel of the control lever 230. Moreover, because each lever axis 231a, 231b is parallel to the respective grip axis 221a, 221b, the operator may be able to grasp the control lever 230 with most, if not all, fingers regardless of the specific position of the control lever 230 relative to the hand grip 220. In contrast, if the control lever 230 were at an angle to the hand grip 220 (e.g., a scissor-type arrangement), the distance (between the control lever 230 and hand grip 220), as well as the force required (to manipulate the control lever 230) may vary depending on the position of a specific finger along the hand grip 220. For example, with respect to a scissor-type control lever, in order for each finger to create an even torque applied across the entire scissor-type control lever, a larger force on the control lever is required closer to the control lever pivot axis than farther away from the control lever pivot axis (e.g., fingers closer to the control lever pivot axis may experience a greater required force than the fingers farther from the control lever pivot axis).
In one or more embodiments, the first control lever 230a may be positioned or located below the first hand grip 220a and the second control lever 230b may be positioned or located below the second hand grip 220b (e.g., when the mower 100 is in the operating configuration). In such embodiments, the control lever 230 is positioned below the hand grip 220 such that the fingers of the operator engage the control lever 230 while the base of the hand abuts the hand grip 220 (e.g., when the mower 100 is in the normal operating configuration). This orientation may allow the operator to manipulate the control lever 230 by simply moving his or her fingers.
The hand grip 220 and the control lever 230 may be shaped in any suitable manner that permits the control lever 230 to be moved relative to the hand grip 220. For example, the control lever 230 may define a shape that is complementary to the hand grip 220 such that when the control lever 230 and the hand grip 220 are adjacent or abut, the combined shape does not present large discontinuities or protrusions that may fatigue the hands over time. In some embodiments, the control lever 230 may include a concave surface that conforms to the circular shape of the hand grip 220.
As described herein, the control lever 230 may pivot relative to the hand grip 220 into different positions (e.g., full forward position, neutral position, full reverse position). For example, as shown in
As shown in
As shown in
The control system 200 may also include a first locking device 240a associated with the first control lever 230a and a second locking device 240b associated with the second control lever 230b, as illustrated in
The locking device 240 may be coupled to the hand grip 220 proximate the control lever 230. Each of the first and second locking devices 240a, 240b may be adapted to pivot about first and second lock pivot axes 243a, 243b, respectively. Each of the first and second lock pivot axes 243a, 243b may be oriented perpendicular to the first and second grip axes 221a, 221b. The locking device 240 may be biased in any suitable way to configure the control lever 230 into a “default” position. For example, the locking device 240 may be biased to pivot in such a way that positions its respective control lever 230 in the neutral position (or, e.g., the full forward position) when the control lever 240 is released by the operator.
As illustrated in
The locking device 240 may be pivotally coupled to the hand grip 220 (e.g., about the lock pivot axis 243) such that the locking device 240 may be adapted to pivot and position the protrusion 235 of the control lever 230 in either one of the first notch 252 (e.g., to configure the control lever 230 in the neutral position) or the second notch 254 (e.g., to configure the control lever 230 in the full forward position). Because the control lever 230 is biased to extend away from the hand grip 220, the operator may force the control lever 230 towards the hand grip 220 and the locking device 240 may be rotated such that upon release of the control lever 230, the protrusion 235 of the control lever 230 may be positioned into the first notch 252 or the second notch 254.
The locking device 240 may further include a first extended portion 242 and a second extended portion 244 that are configured to assist in rotating the locking device 240 about the lock pivot axis 243. For example, a force applied to the first extended portion 242 (e.g., via the operator's thumb) results in a rotation of the locking device 240 in a direction 248 that aligns the protrusion 235 to be positioned in the first notch 252 (e.g., the neutral position as illustrated in
The control system 200 may also include one or more secondary levers 260 (e.g., operator presence levers) associated with one or both of the first hand grip 220a and the second hand grip 220b as illustrated in
The one or more secondary levers 260 may be positioned proximate the respective hand grip 220 and opposite the control lever 230. The one or more secondary levers 260 may be pivotable about a secondary lever axis 263 (e.g., as shown in
Illustrative embodiments are described and reference has been made to possible variations of the same. These and other variations, combinations, and modifications will be apparent to those skilled in the art, and it should be understood that the claims are not limited to the illustrative embodiments set forth herein.