Parking brake for a lawn care vehicle

Abstract

A brake assembly for a riding lawn care vehicle may include a rotor assembly including a rotor plate having a plurality of through-holes extending through the rotor plate, a hub adapter assembly operably coupling the rotor plate to a drive wheel of the vehicle to cause the rotor plate to rotate with the drive wheel, and a caliper assembly including a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly. The pressure plate may include a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the drive wheel responsive to actuation of the actuator assembly.

Description

[0001] PARKING BRAKE FOR A LAWN CARE VEHICLE

[0002] TECHNICAL FIELD

[0003] Example embodiments generally relate to brake systems in lawn care vehicles and, more particularly, to a riding lawn care vehicle with a relatively simple construction, but highly capable parking brake.

[0004] BACKGROUND

[0005] 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.

[0006] 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 and, more recently, lawn mowers with short or near zero turning capabilities have typically employed steering levers. When these 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 drive wheel is then driven forward or backward based on whether the corresponding steering lever is also pushed forward or pulled backward toward the operator.

[0007] Currently, transmissions with internal parking brakes are generally used to provide parking brake functions for these types of vehicles. Additionally, a brake caliper and friction pads are often employed as parking brakes for these types of vehicles. Meanwhile, cost pressures have urged manufacturers toward the use of smaller transmissions. While such transmissions may be generally able to perform needed functions for relatively heavy zero turn mowers, the parking brake functions may not be sufficiently robust. Thus, some example embodiments provide a more robust capacity for parking brake functionality, as described in greater detail below.

[0008] BRIEF SUMMARY OF SOME EXAMPLES

[0009] In one example embodiment, a riding lawn care vehicle with an improved brake assembly may be provided. The 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 including a first steering lever and a second steering lever, where the first and second steering levers are 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, and a brake assembly operably coupled to the first and second drive wheels to enable brakes to be selectively applied to the first and second drive wheels. The brake assembly may include a rotor assembly including a rotor plate having a plurality of through-holes extending through the rotor plate, a hub adapter assembly operably coupling the rotor plate to the first drive wheel or the second drive wheel to cause the rotor plate to rotate with the first drive wheel or the second drive wheel, and a caliper assembly including a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly. The pressure plate may include a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the first drive wheel or the second drive wheel responsive to actuation of the actuator assembly.

[0010] In another example embodiment, a brake assembly for a riding lawn care vehicle is provided. The brake assembly may include a rotor assembly including a rotor plate having a plurality of through-holes extending through the rotor plate, a hub adapter assembly operably coupling the rotor plate to a drive wheel of the vehicle to cause the rotor plate to rotate with the drive wheel, and a caliper assembly including a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly. The pressure plate may include a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the drive wheel responsive to actuation of the actuator assembly.

[0011] Some example embodiments may improve the ability of manufacturers to use smaller transmissions on heavy machines without any sacrifice in the stopping and holding capability of the parking brake. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0012] 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:

[0013] FIG. 1 A illustrates a perspective view of a riding lawn care vehicle according to an example embodiment;

[0014] FIG. IB illustrates a top view of the riding lawn care vehicle according to an example embodiment;

[0015] FIG. 2 illustrates a perspective view of a brake assembly of an example embodiment;

[0016] FIG. 3 A illustrates a perspective view of a brake assembly according to an example embodiment from an inside perspective (looking outwardly);

[0017] FIG. 3B illustrates a perspective view of a rotor assembly according to an example embodiment from an outside perspective (looking inwardly);

[0018] FIG. 4 illustrates a perspective view of a rotor assembly in accordance with an example embodiment;

[0019] FIG. 5 illustrates a perspective view of the rotor assembly and hub adapter assembly from an outside perspective in accordance with an example embodiment;

[0020] FIG. 6 is a perspective view of rotor-to-hub adapter in accordance with an example embodiment;

[0021] FIG. 7 illustrates a perspective view of a hub member in accordance with an example embodiment;

[0022] FIG. 8A is an isolated perspective view of an actuator assembly in accordance with an example embodiment from an inside perspective (looking outwardly);

[0023] FIG. 8B is another isolated perspective view of the actuator assembly in accordance with an example embodiment from an outside perspective (looking inwardly);

[0024] FIG. 9 illustrates an isolated perspective view of an input shaft in accordance with an example embodiment;

[0025] FIG. 10 illustrates an isolated perspective view of an actuation pulley in accordance with an example embodiment;

[0026] FIG. 11 illustrates an isolated perspective view of a lead screw nut in accordance with an example embodiment;

[0027] FIG. 12A illustrates an isolated perspective view of a pressure plate in accordance with an example embodiment from an outside perspective; FIG. 12B illustrates an isolated perspective view of the pressure plate in accordance with an example embodiment from an inside perspective;

[0028] FIG. 13 illustrates an isolated perspective view of a caliper assembly in accordance with an example embodiment;

[0029] FIG. 14A illustrates an isolated perspective view of a caliper housing in accordance with an example embodiment from an inside perspective;

[0030] FIG. 14B illustrates an isolated perspective view of the caliper housing in accordance with an example embodiment from an outside perspective;

[0031] FIG. 15 illustrates an isolated perspective view of a pawl in accordance with an example embodiment;

[0032] FIG. 16A illustrates an isolated perspective view of the pressure plate with pawls and lead screw nut installed in accordance with an example embodiment from an outside perspective;

[0033] FIG. 16B illustrates an isolated perspective view of the pressure plate with pawls and lead screw nut installed in accordance with an example embodiment from an inside perspective;

[0034] FIG. 17A illustrates a first housing plate with compression springs provided thereon in accordance with an example embodiment;

[0035] FIG. 17B illustrates the further addition of the pressure plate of FIG. 16A installed on mounting posts of the caliper housing in accordance with an example embodiment;

[0036] FIG. 18 illustrates a perspective view of the caliper assembly with actuation pulley and mounting poles removed in accordance with an example embodiment; and

[0037] FIG. 19 illustrates an isolated perspective view of the mounting poles in accordance with an example embodiment.

[0038] DETAILED DESCRIPTION

[0039] 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.

[0040] Some example embodiments may improve the ability of a manufacturer to provide a robust parking brake that allows a lighter transmission to be employed in otherwise heavy machines. The parking brake described herein employs some familiarly named components including a caliper, rotor, drive wheel hub, etc. However, even these familiarly named components have modified structures that improve performance in this particular context.

[0041] FIGS. 1A and IB illustrate 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. IB 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.

[0042] The operator may sit on the seat 20, which may be disposed between or 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 shown specifically in FIG. IB.

[0043] 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.

[0044] 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 A and IB, 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. In the depicted example, the wheels 31 are unpowered caster wheels and the engine 50 only provides power to the wheels 32, which are rear wheels in this case. 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.

[0045] 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 toward the wheels 31) and rearward (i.e., in the direction away from the wheels 31) while in the inboard position (shown in both FIGS. 1A and IB).

[0046] When a steering lever 34 is pushed forward (e.g., away from the operator and toward wheels 31), the corresponding hydraulic motor may drive the corresponding wheel forward. When a steering lever 34 is pulled rearward (e.g., toward the operator and away from the wheels 31), 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.

[0047] Although the steering levers 34 are generally moved forward or backward in any desirable combination while they are in the operating positions shown in FIGS. 1A and IB, 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. IB. 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 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.

[0048] 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 set of linkages or other operable coupling to set the brake assembly. Whether the brake assembly is set by movement of a dedicated brake lever, via pushing a button, or via moving steering levers outboard, once set (and particularly so for parking), it is expected that the brake assembly should be able to hold the vehicle stationary even on inclined surfaces. Example embodiments provide a robust structure for doing so.

[0049] In this regard, turning to FIG. 2, a perspective via of a brake assembly 100 of an example embodiment is shown. The brake assembly 100 is disposed at an internal side of one of the drive wheels (i.e., wheel 32) of FIGS. 1A and IB. Thus, the brake assembly 100 is positioned between the wheel 32 and the frame 60. The brake assembly 100 includes a rotor assembly 110 and a caliper assembly 120 that will be described in greater detail below. The rotor assembly 110 is mounted to a hub portion of the wheel 32 via a hub adapter assembly 130. Generally speaking, the caliper assembly 120 is operable responsive to setting of the brake assembly 100 (e.g., via any of the methods described above) to engage the rotor assembly 110 and prevent rotational movement of the wheel 32. The prevention of rotational movement is provided in part due to the fact that the rotor assembly 110 is otherwise generally rotated with the wheel 32 and is rigidly affixed to the hub portion of the wheel 32 via the hub adapter assembly 130. Thus, when the wheel 32 rotates, the rotor assembly 110 also rotates correspondingly, and when the rotor assembly 110 is prevented from rotating by engagement with the caliper assembly 120, neither the rotor assembly 110 nor the wheel 32 may be permitted to rotate.

[0050] While FIG. 2 shows the brake assembly 100 in its operational context, FIGS. 3A and 3B show the brake assembly 100 in isolation from opposing perspective views. In this regard, FIG. 3 A is a perspective view of the brake assembly 100 from inside (i.e., from a position proximate a longitudinal centerline of the riding lawn care vehicle 10) and FIG. 3B is a perspective view of the brake assembly 100 from outside (i.e., looking toward the longitudinal centerline of the riding lawn care vehicle 10).

[0051] Referring primarily to FIGS. 3 A and 3B, the rotor assembly 110 can be seen to include a rotor plate 200 and mounting members 202 that interface with the hub adapter assembly 130. Meanwhile, the caliper assembly 120 may include a caliper housing 400 inside which a portion of the rotor plate 200 extends to interface with various braking components housed inside the caliper housing 400. These various braking components will be discussed in greater detail below. However, at least for now, it should be appreciated that an actuator assembly 220 (which includes an actuation cable 222, an actuation pulley 224, and an input shaft 226) may be operated by the operator of the riding lawn care vehicle 10 to set the brake assembly 100 via a lever, button, or other actuator that is accessible and operable to the operator while seated or otherwise operating the riding lawn care vehicle 10. When set (i.e., when the actuator assembly 220 is actuated), the actuation cable 222 may provide cable tension to rotate the actuation pulley 224, and such rotation may cause movement of the various braking components that are to be discussed in greater detail below to engage the rotor plate 200 and prevent rotation thereof. The prevention of rotation of the rotor plate 200 may in turn prevent rotation of the wheel 32 due to the operable coupling of the rotor plate 200 to the wheel 32 via the hub adapter assembly 130.

[0052] The hub adapter assembly 130 and rotor assembly 110 will each next be discussed in detail in relation to an example embodiment. In this regard, components of the rotor assembly 110 of an example embodiment are shown in isolation FIG. 4. FIG. 4 shows a perspective view (from inside) of the rotor assembly 110.

[0053] The rotor plate 200 may be generally formed as a circular plate, all of which lies in a plane. Meanwhile, the rotor plate 200 may have a plurality of through-holes 230 formed therein, and the through-holes 230 may pass perpendicularly through the plane and the rotor plate 200. The through-holes 230 may be disposed proximate to a periphery of the rotor plate 200 equidistantly spaced apart from each other. The through-holes 230 may also each have an equal (and relatively small) spacing from a peripheral edge 232 of the rotor plate 200, and may also be equidistant from a rotational axis or center of the rotor plate 200.

[0054] The rotor assembly 110 may also include the mounting members 202, which are also equidistantly spaced apart from each other, and from the rotational axis or center of the rotor plate 200. The mounting members 202 (e.g., screws, bolts or other fasteners) may therefore extend through the rotor plate 200 and perpendicularly away from the rotor plate 200 and the plane to engage with a portion of the hub adapter assembly 130. The rotor plate 200 may also include an axial channel 240 that encompasses the rotational axis or center of the rotor plate 200 to allow axle and / or hub components to pass therethrough.

[0055] FIG. 5 shows a perspective view (from outside) of the rotor assembly 110 and the hub adapter assembly 130 in isolation, and engaged with each other. In particular, the hub adapter assembly 130 includes a rotor-to-hub adapter 250 shown in perspective view in isolation in FIG. 6 and a hub member 260 shown in perspective view in isolation in FIG. 7. Referring to FIGS. 5-7, the rotor-to-hub adapter 250 includes a body portion 252, mounting member receivers 254, and a hex shaped aperture 256 that passes through the body portion 252 at an axis thereof. The mounting member receivers 254 also pass through the body portion 252, and are aligned with the mounting members 202 of the rotor assembly 110 to allow the mounting members 202 to pass therethrough to affix the rotor plate 200 to the body portion 252. Thus, the mounting member receivers 254 may be threaded to receive and engage threads of the mounting members 202, or in alternative embodiments, the mounting members 202 may further have a threaded nut or other fastener attached to a distal end thereof to affix the mounting members 202 in place relative to the body portion 252.

[0056] Meanwhile, the hex shaped aperture 256 may be shaped to receive a hex shaped protrusion 262 of the hub member 260 (shown in FIG. 7). The hex shaped protrusion 262 may extend away from a body portion 264 of the hub member 260 and, in some cases, may further extend through the axial channel 240 of the rotor plate 200. The body portion 264 may further be attachable to a rim or other portion of the wheel 32 via fasteners 266 that pass through the body portion 264 to engage the rim or other portion of the wheel 32. An axle nut 268 may also be provided to affix the hub adapter assembly 130 to an axle of the riding lawn care vehicle 10. Thus, the body portion 264 of the hub member 260 may be affixed to the rim or other portion of the wheel 32, and also keyed to drive movement of the rotor-to-hub adapter 250 via engagement of the hex shaped protrusion 262 with the hex shaped aperture 256. Based on the connections described above, it can be appreciated that the rotation of the wheel 32 carries with it corresponding rotation of the rotor plate 200. Therefore, fixing the rotor plate 200 to prevent its rotation (by applying braking forces that will be discussed in reference to components in the caliper assembly 120) will also fix the wheel 32 and prevent its rotation.

[0057] Components of the caliper assembly 120 will now be described in greater detail in reference to FIGS. 8A-19. Turning first to FIGS. 8A and 8B, opposing perspective views are shown of the actuator assembly 220. Meanwhile, FIG. 9 shows the input shaft 226 in isolation and FIG. 10 shows the actuation pulley 224 in isolation. The actuation pulley 224 further includes a grooved channel 225 in which the actuation cable 222 may be routed. The grooved channel 225 may be V-shaped and extend circumferentially around the actuation pulley 224. Moreover, the actuation pulley 224 may be made of plastic or a fiber reinforced composite or plastic material that converts a pulling or linear force on the actuation cable 222 into a rotational force applied to the input shaft 226, which in turn is converted into linear movement parallel to a rotational axis of the rotor plate 200 as described in greater detail below. However, notably, an electronic rotary actuator could be used in place of the actuation cable 222 and actuation pulley 224 in some alternative embodiments.

[0058] As shown in FIGS. 8A-10, the input shaft includes a splined portion 300 and a threaded portion 310. The splined portion 300 is operably coupled to a corresponding splined channel 320 formed at an axial center of the actuation pulley 224. The splined channel 320 and the splined portion 300 mate with each other to ensure that rotation of the actuation pulley 224 (responsive to movement of the actuation cable 222) causes corresponding rotation of the input shaft 226. The threaded portion 310 of the input shaft 226 is exposed relative to the actuation pulley 224, and is available for interface with a lead screw nut 330 shown in FIG. 11. The lead screw nut 330 of FIG. 11 has internal threads 332 that engage with the threaded portion 310 of the input shaft 226, and also has external threads 334. The threaded portion 310 therefore acts as a lead screw on which the lead screw nut 330 translates when rotated. The direction of translation is parallel to an axis of the rotor plate 200. The external threads 334 affix the lead screw nut 330 to a pressure plate 340 having a threaded opening 341 shown in FIGS. 12A and 12B. Meanwhile, the lead screw nut 330 translates along the threaded portion 310 responsive to rotation of the input shaft 226, and the interaction of the threaded portion 310 of the input shaft 226 with the internal threads 332 of the lead screw nut 330. Since the lead screw nut 330 translates along the input shaft 226 (specifically along the threaded portion 310 thereof), it can be appreciated that the pressure plate 340 is carried by the lead screw nut 330 and also translates relative to the input shaft 226 along a direction parallel to the axis of the rotor plate 200.

[0059] The pressure plate 340 is part of an overall structure shown in FIG. 13, which is a perspective view of the caliper assembly 120 in isolation, that applies braking force to hold the rotor plate 200 (and therefore also the wheel 32) stationary, when set or activated. In this regard, the caliper assembly 120 includes a caliper housing 400 (shown in isolation from two perspectives in FIGS. 14A and 14B) formed from a first housing plate 410 and a second housing plate 412. The caliper housing 400 also includes posts 420 (which may be countersunk into the first and / or second housing plates 410 and 412) that operably couple the first and second housing plates 410 and 412 and define an operating space 430 therebetween. In this regard, the posts 420 act as spacers to define an equidistant separation between the first and second housing plates 410 and 412 based on a length of the posts 420. In between the posts 420, the first and second housing plates 410 and 412 may further include mounting pole apertures 440, which may be used for mounting the caliper housing 400 as described in greater detail below.

[0060] Meanwhile, as noted above, when assembled, the rotor plate 200 (or a portion thereof) is disposed inside the operating space 430, and more specifically is disposed proximate to the pressure plate 340. The riding of the lead screw nut 330 on the input shaft 226 responsive to rotation of the lead screw nut 330 based on corresponding rotation of the actuation pulley 224 due to movement of the actuation cable 222 (based on actuation of a lever, button or other operator / actuator by the operator) will cause pawls 450 disposed at the pressure plate 340 to be extended into respective ones of the through-holes 230 to lock the rotor plate 200 in place.

[0061] An example of the pawls 450 is shown in isolation in FIG. 15, and opposing perspective views of the pawls 450 installed in the pressure plate 340 are shown in FIGS. 16A and 16B. The pawls 450 may be screwed into the pressure plate 340 at locations spaced apart to correlate to the distance between through-holes 230. The pawls 450 may have a diameter about equal to a diameter of the through-holes 230, but may have a beveled distal edge in order to allow the pawls 450 to fit into the through-holes 230 when actuated even if there is some small misalignment between the pawls 450 and the through-holes 230. This allows not only for easy insertion of the pawls 450 into the through-holes 230, but may also facilitate easy removal of the pawls 450, which still providing good locking or holding functionality while the pawls 450 are inserted into the through-holes 230. Notably, although this example depicts two pawls 450 provided on the pressure plate 340, the pressure plate 340 could alternatively only have a single instance of the pawl 450, or may have three or more such instances, so long as simultaneous insertion into the through-holes 230 is permissible by the positioning of the pawls 450. Moreover, the pawls 450 may be replaceable if worn or damaged, which may present an advantage over any integrally formed design in which the pawls 450 are a permanent protrusion instead of a removable element. Also, it is noteworthy that the pawls 450 need not have a circular periphery, and other shapes could be employed in some embodiments.

[0062] The pressure plate 340 may also be biased toward engagement with the rotor plate 200 by compression springs 500. In this regard, the compression springs 500 may be compressed between the pressure plate 340 and the first housing plate 410. FIG. 17A shows the compression springs 500 in contact with the first housing plate 410 prior to insertion of the pressure plate 340 onto the posts 420. The pressure plate 340 includes guide apertures 342 that ride along the posts 420 as the pressure plate is translated or carried responsive to rotation of the input shaft 226. When the pressure plate 340 is installed with the guide apertures 342 riding on the posts 420, the compression springs 500 are compressed in an inboard or inward direction (i.e., toward the frame 60 of FIG. 2). The compression springs 500 press or bias the pressure plate 340 away from the first housing plate 410 and toward the second housing plate 412 (and also the rotor plate 200). In an example embodiment, some or all of the openings or apertures formed in the pressure plate 340 may be counter-bored holes in order to support shear load from the pawls 450 when the pawls 450 are inserted into the through-holes 230.

[0063] The assembled caliper housing 400 with internal components therein is shown in FIG. 18 in perspective view. In this regard, the input shaft 226 extends through an aperture 510 formed in the first housing plate 410, and the actuation pulley 224 can be slid over the splined portion 300 of the input shaft 226 during assembly. As noted above, both the first and second housing plates 410 and 412 include mounting pole apertures 440 that align with each other and through which mounting poles 520 may slidably pass. The mounting poles 520 may include fasteners on one end thereof (i.e., the end closest to the actuation pulley 224) to affix the caliper housing 400 directly or indirectly to the frame 60. Notably, although the mounting poles 520 are shown with a circular cross section, they may have any cross sectional shape. The mounting poles 520 may also include biasing springs 530 disposed at the other end thereof (i.e., the end opposite the actuation pulley 224). The biasing springs 530 (shown in isolation in FIG. 19) may bias the caliper housing 400 away from the outboard side and position the second housing plate 412 to be proximate to the rotor plate 200.

[0064] The insertion of the rotor plate 200 into the operating space 430 with corresponding biasing of elements on both sides thereof with springs creates flexibility in design tolerance for assembly. In this regard, for example, the structures described above provide the ability to brake or hold the rotor plate 200 stationary (and therefore also hold the corresponding drive wheel (e.g., wheel 32) stationary) in such a way as to have simultaneous rotation about the axis of rotation (of the rotor plate 200) while allowing the rotor plate 200 to slide along the axis of rotation and thereby allow for tolerance slack in the assembly of parts. The shaped interface (e.g., hex aperture and hex protrusion) of the hub adapter assembly 130, and the splined interface between the input shaft 226 and the actuation pulley 224 further allow simultaneous rotation about the axis to occur, while still enabling freedom of motion of parts along the axis. Thus, the rotor plate 200 and other components can all slide along the axis of rotation without interrupting proper functioning of the components.

[0065] The assembly described above also has the advantage of defining a default situation in which the brake forces generated are normally on or applied. Thus, force application (via the actuator assembly 220) is required in order to allow the rotor plate 200 to rotate. If there is no power, the rotor plate 200 will be locked by this default operation (e.g., due to operation of compression springs 500).

[0066] Assembly of the structures described above may begin with attachment of the posts 420 to the first housing plate 410. Thereafter, the compression springs 500 may be placed at the first housing plate 410 before the pressure plate 340 (with pawls 450 and lead screw nut 330 already affixed thereto) is installed over the posts 420. The second housing plate 412 may then be installed to complete the caliper housing 400. The input shaft 226 may be operably coupled to the internal threads 332 of the lead screw nut 330 and then the actuation pulley 224 may be attached to the input shaft 226 and operably coupled to the actuation cable 222. The mounting poles 520 may then be inserted through the mounting pole apertures 440 in the first and second housing plates 410 and 412, and affixed to the frame 60 to straddle the rotor plate 200 (which may be previously installed with the hub adapter assembly 130. The biasing springs 530 may be placed on the outboard side of the caliper housing 400, and the actuation pulley 224 may be oriented inwardly.

[0067] Accordingly, some example embodiments may provide a riding lawn care vehicle with an improved brake assembly (e.g., for providing a parking brake function), or simply the brake assembly itself. 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 including a first steering lever and a second steering lever, where the first and second steering levers are 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, and a brake assembly operably coupled to the first and second drive wheels to enable brakes to be selectively applied to the first and second drive wheels. The brake assembly may include a rotor assembly including a rotor plate having a plurality of through- holes extending through the rotor plate, a hub adapter assembly operably coupling the rotor plate to the first drive wheel or the second drive wheel to cause the rotor plate to rotate with the first drive wheel or the second drive wheel, and a caliper assembly including a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly. The pressure plate may include a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the first drive wheel or the second drive wheel responsive to actuation of the actuator assembly.

[0068] The riding lawn care vehicle (or brake 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 actuator assembly may include an actuation cable, an actuation pulley and an input shaft, and the actuator assembly may be actuated by repositioning the actuation pulley via the actuation cable. In an example embodiment, the input shaft may include a threaded portion and a splined portion. The splined portion may be operably coupled to the actuation pulley, and a lead screw nut may ride on the threaded portion to carry the pressure plate toward or away from the rotor plate within the caliper housing. In some cases, the caliper housing may include a first housing plate and a second housing plate. The first housing plate may be a fixed distance from the second housing plate, the actuation pulley may be disposed on an opposite side of the first housing plate as the second housing plate, and a portion of the splined portion may pass through the first housing plate to engage the actuation pulley. In an example embodiment, the first and second housing plates may each include mounting pole apertures through which mounting poles slidably pass, and biasing springs may be provided on the mounting poles to bias the caliper housing toward the actuation pulley. In some cases, the pressure plate may be biased away from the first housing plate via a compression spring disposed between the pressure plate and the first housing plate. In an example embodiment, the pressure plate may be translated responsive to rotation of the lead screw nut along one or more posts that pass through the pressure plate to insert the pawl into the one of the through-holes or to withdraw the pawl from the one of the through-holes. In some cases, the hub adapter assembly may include a rotor-to-hub adapter and a hub member, where the rotor-to-hub adapter is operably coupled to the rotor plate via one or more fasteners, the hub member is operably coupled to the first drive wheel or the second drive wheel via one or more fasteners, and the rotor-to-hub adapter and the hub member are operably coupled to each other via a shaped interface. In an example embodiment, the shaped interface may be formed via a hex shaped aperture formed in a body portion of the rotor-to-hub adapter and a hex shaped protrusion formed at a body portion of the hub member. In some cases, the pressure plate may be biased to prevent rotation of the rotor plate, and the actuator assembly may overcome biasing of the pressure plate to allow rotation of the rotor plate responsive to actuation of the actuator assembly. In an example embodiment, the riding lawn care vehicle may be a zero turn mower.

[0069] 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.

Claims

THAT WHICH IS CLAIMED:

1. A riding lawn care vehicle comprising: 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 comprising a first steering lever and a second steering lever, wherein the first and second steering levers are 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; and a brake assembly operably coupled to the first and second drive wheels to enable brakes to be selectively applied to the first and second drive wheels, wherein the brake assembly comprises: a rotor assembly comprising a rotor plate having a plurality of through-holes extending through the rotor plate; a hub adapter assembly operably coupling the rotor plate to the first drive wheel or the second drive wheel to cause the rotor plate to rotate with the first drive wheel or the second drive wheel; and a caliper assembly comprising a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly, wherein the pressure plate comprises a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the first drive wheel or the second drive wheel responsive to actuation of the actuator assembly.

2. The riding lawn care vehicle of claim 1, wherein the actuator assembly comprises an actuation cable, an actuation pulley and an input shaft, and wherein the actuator assembly is actuated by repositioning the actuation pulley via the actuation cable.

3. The riding lawn care vehicle of claim 2, wherein the input shaft comprises a threaded portion and a splined portion, wherein the splined portion is operably coupled to the actuation pulley, andwherein a lead screw nut rides on the threaded portion to carry the pressure plate toward or away from the rotor plate within the caliper housing.

4. The riding lawn care vehicle of claim 3, wherein the caliper housing comprises a first housing plate and a second housing plate, wherein the first housing plate is a fixed distance from the second housing plate, wherein the actuation pulley is disposed on an opposite side of the first housing plate as the second housing plate, and wherein a portion of the splined portion passes through the first housing plate to engage the actuation pulley.

5. The riding lawn care vehicle of claim 4, wherein the first and second housing plates each comprise mounting pole apertures through which mounting poles slidably pass, and wherein biasing springs are provided on the mounting poles to bias the caliper housing toward the actuation pulley.

6. The riding lawn care vehicle of claim 3, wherein the pressure plate is biased away from the first housing plate via a compression spring disposed between the pressure plate and the first housing plate.

7. The riding lawn care vehicle of claim 6, wherein the pressure plate is translated responsive to rotation of the lead screw nut along one or more posts that pass through the pressure plate to insert the pawl into the one of the through-holes or to withdraw the pawl from the one of the through-holes.

8. The riding lawn care vehicle of claim 1, wherein the hub adapter assembly comprises a rotor-to-hub adapter and a hub member, wherein the rotor-to-hub adapter is operably coupled to the rotor plate via one or more fasteners, wherein the hub member is operably coupled to the first drive wheel or the second drive wheel via one or more fasteners, and wherein the rotor-to-hub adapter and the hub member are operably coupled to each other via a shaped interface.

9. The riding lawn care vehicle of claim 8, wherein the shaped interface is formed via a hex shaped aperture formed in a body portion of the rotor-to-hub adapter and a hex shaped protrusion formed at a body portion of the hub member.

10. The riding lawn care vehicle of claim 1, wherein the pressure plate is biased to prevent rotation of the rotor plate, and wherein the actuator assembly overcomes biasing of the pressure plate to allow rotation of the rotor plate responsive to actuation of the actuator assembly.

11. The riding lawn care vehicle of any of claims 1 to 10, wherein the riding lawn care vehicle is a zero turn mower.

12. A brake assembly for a riding lawn care vehicle, the brake assembly comprising: a rotor assembly comprising a rotor plate having a plurality of through-holes extending through the rotor plate; a hub adapter assembly operably coupling the rotor plate to a drive wheel of the vehicle to cause the rotor plate to rotate with the drive wheel; and a caliper assembly comprising a caliper housing, an actuator assembly, and pressure plate movable within the caliper housing responsive to actuation of the actuator assembly, wherein the pressure plate comprises a pawl insertable into one of the through-holes to prevent rotation of the rotor plate and the drive wheel responsive to actuation of the actuator assembly.

13. The brake assembly of claim 12, wherein the actuator assembly comprises an actuation cable, an actuation pulley and an input shaft, and wherein the actuator assembly is actuated by repositioning the actuation pulley via the actuation cable.

14. The brake assembly of claim 13, wherein the input shaft comprises a threaded portion and a splined portion, wherein the splined portion is operably coupled to the actuation pulley, and wherein a lead screw nut rides on the threaded portion to carry the pressure plate toward or away from the rotor plate within the caliper housing.

15. The brake assembly of claim 14, wherein the caliper housing comprises a first housing plate and a second housing plate, wherein the first housing plate is a fixed distance from the second housing plate, wherein the actuation pulley is disposed on an opposite side of the first housing plate as the second housing plate, and wherein a portion of the splined portion passes through the first housing plate to engage the actuation pulley.

16. The brake assembly of claim 15, wherein the first and second housing plates each comprise mounting pole apertures through which mounting poles slidably pass, and wherein biasing springs are provided on the mounting poles to bias the caliper housing toward the actuation pulley.

17. The brake assembly of claim 14, wherein the pressure plate is biased away from the first housing plate via a compression spring disposed between the pressure plate and the first housing plate.

18. The brake assembly of claim 17, wherein the pressure plate is translated responsive to rotation of the lead screw nut along one or more posts that pass through the pressure plate to insert the pawl into the one of the through-holes or to withdraw the pawl from the one of the through-holes.

19. The brake assembly of claim 12, wherein the hub adapter assembly comprises a rotor-to-hub adapter and a hub member, wherein the rotor-to-hub adapter is operably coupled to the rotor plate via one or more fasteners, wherein the hub member is operably coupled to the first drive wheel or the second drive wheel via one or more fasteners, and wherein the rotor-to-hub adapter and the hub member are operably coupled to each other via a shaped interface.

20. The brake assembly of claim 19, wherein the shaped interface is formed via a hex shaped aperture formed in a body portion of the rotor-to-hub adapter and a hex shaped protrusion formed at a body portion of the hub member.

21. The brake assembly of claim 12, wherein the pressure plate is biased to prevent rotation of the rotor plate, and wherein the actuator assembly overcomes biasing of the pressure plate to allow rotation of the rotor plate responsive to actuation of the actuator assembly.

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