Patent Description:
Fuel costs and an increased awareness of pollution and other byproducts of fossil fuel have generated much interest in the development of cleaner energy sources. Battery powered vehicles have a potential for reducing dependence on fossil fuels. However, it should be appreciated that many new design considerations that were not issues previously may come into play when battery powered vehicles are employed.

<CIT> discloses a transmission device between a primary motor shaft and a drive shaft for the wheels of self-propelled lawn mowers having a driving member connectabl to a motor shaft, an output shaft, and a helically threaded driven gear rotatably mounted and movable axially on the output shaft.

Some example embodiments may provide for a drive assembly for a lawn care vehicle according to the invention. In this regard, the drive assembly may be configured to accomplish a large gear reduction ratio in a compact space while also eliminating a need for a parking brake system on the lawn care vehicle according to the invention. Furthermore, the drive assembly may be configured to move between a plurality of configurations which allows a mobility assembly of the lawn care vehicle according to the invention to be manually pushed or towed or powered by an electric motor.

According to the invention, a lawn care vehicle is provided. The lawn care vehicle includes a motor; a mobility assembly to provide mobility to the lawn care vehicle; a working assembly operably coupled to the motor to perform a working function responsive at least in part to operation of the motor; and a drive assembly for selectively coupling the motor of the vehicle to the mobility assembly of the vehicle to provide mobility to the vehicle responsive at least in part to operation of the motor. The drive assembly includes a worm gear assembly having a worm engaged with a worm gear. The worm is operably coupled to the motor of the vehicle, and the worm gear is selectively coupled to a shaft of the mobility assembly. The drive assembly is configured to move between a first configuration and a second configuration. In response to the drive assembly being in the first configuration, the worm gear assembly and the shaft of the mobility assembly are operably coupled, and the worm gear assembly is configured to selectively transfer power from the motor to the mobility assembly to provide mobility to the vehicle. In response to the drive assembly being in a second configuration, the worm gear assembly and the shaft of the mobility assembly are decoupled, and the worm gear assembly is prevented from transferring the power from the motor to the mobility assembly.

A lawn care vehicle according to the invention is defined in claim <NUM>.

In an exemplary embodiment, a drive assembly for the lawn care vehicle is provided. The drive assembly for the vehicle may selectively couple a motor of the vehicle to a mobility assembly of the vehicle to provide mobility to the vehicle responsive at least in part to operation of the motor. The drive assembly may include a worm gear assembly having a worm engaged with a worm gear. The worm may be operably coupled to the motor of the vehicle, and the worm gear may be selectively coupled to a shaft of the mobility assembly. The drive assembly may be configured to move between a first configuration and a second configuration. In response to the drive assembly being in the first configuration, the worm gear assembly and the shaft of the mobility assembly may be operably coupled, and the worm gear assembly may be configured to selectively transfer power from the motor to the mobility assembly to provide mobility to the vehicle. In response to the drive assembly being in a second configuration, the worm gear assembly and the shaft of the mobility assembly may be decoupled, and the worm gear assembly may be prevented from transferring the power from the motor to the mobility assembly.

Having thus described embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:.

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 invention.

Rather, these example embodiments are provided so that this invention will satisfy applicable legal requirements. 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, operable coupling 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 provide for a drive assembly for a lawn care vehicle according to the invention. As noted above, the drive assembly may accomplish a large gear reduction ratio in a compact space with minimal components while also eliminating a need for a parking brake system on the vehicle. Furthermore, the drive assembly may be configured to move between a plurality of configurations which allows a mobility assembly of the vehicle to be manually pushed or towed or powered by a motor.

<FIG> illustrate a riding lawn care vehicle <NUM> according to an example embodiment. <FIG> illustrates a perspective view of the riding lawn care vehicle <NUM> and <FIG> illustrates a top view of the riding lawn care vehicle <NUM> according to an example embodiment. Furthermore, <FIG> illustrates a block diagram of various components of the riding lawn care vehicle <NUM> to illustrate operable coupling provided between various of such components and to facilitate description of an example embodiment. While example embodiments described herein relate to a battery-powered riding lawn care vehicle, it should be understood that a drive assembly according to example embodiments herein may be employed on other vehicles. In this regard, in accordance with other example embodiments, the vehicle may be a gasoline-powered vehicle.

As shown in <FIG> and <FIG>, the riding lawn care vehicle <NUM> may include a seat <NUM> that may be disposed at a center, rear, or front portion of the riding lawn care vehicle <NUM>. The riding lawn care vehicle <NUM> may also include a steering assembly <NUM> (e.g., a set of zero turn mower steering levers <NUM> with shaft <NUM> or the like) functionally connected to a mobility assembly <NUM> (e.g., wheels <NUM> and <NUM>) of the riding lawn care vehicle <NUM> to allow the operator to steer the riding lawn care vehicle <NUM>. For example, the operator may sit on the seat <NUM>, which may be disposed to the rear of the steering assembly <NUM>, to provide input for steering of the riding lawn care vehicle <NUM> via the steering assembly <NUM>. However, some models may be stand-up models that eliminate the seat <NUM>. If the seat <NUM> is eliminated, the operator typically stands at an operator station proximate to the steering assembly <NUM>.

The steering assembly <NUM> may include steering levers <NUM> and a shaft <NUM>. In some example embodiments, the steering assembly <NUM> may be embodied as an assembly of metallic or other rigid components that may be welded, bolted or otherwise attached to each other and operably coupled to the wheels <NUM> of the riding lawn care vehicle <NUM> to which steering inputs are provided. When a steering lever <NUM> is pushed forward (e.g., away from the operator towards the front of the vehicle), a corresponding wheel <NUM>, <NUM> may move forward. When a steering lever <NUM> is pulled backward, the corresponding wheel <NUM>, <NUM> may drive backward or rearward. Thus, when both steering levers <NUM> are pushed forward the same amount, the riding lawn care vehicle <NUM> may travel forward in substantially a straight line since approximately the same amount of forward drive input is provided to each drive wheel <NUM>, <NUM>. When both steering levers are pulled back the same amount, the riding lawn care vehicle <NUM> may travel backward in substantially a straight line since approximately the same amount of rearward drive input is provided to each drive wheel <NUM>, <NUM>. When one steering lever <NUM> is pushed forward and the other steering lever <NUM> is pulled back, the riding lawn care vehicle <NUM> may begin to turn in a circle. Steering right and left may be accomplished by providing uneven amounts of input to the steering levers <NUM>. Other steering control systems may be employed in some alternative embodiments.

As noted above, the riding lawn care vehicle <NUM> may also include the mobility assembly <NUM>. The mobility assembly <NUM> may include drivable components such as the wheels <NUM>, <NUM> (e.g., a pair of rear wheels <NUM> being disposed at a rear of the riding lawn care vehicle <NUM> and a pair of front wheels <NUM> being disposed at a front of the riding lawn care vehicle <NUM>). However, in accordance with other example embodiments, the drivable components may be continuous tracks or any other suitable component that may be powered to cause the riding lawn care vehicle <NUM> to move over a ground or surface. In an example embodiment, the rear wheels <NUM> may be provided on a drive or output shaft on opposing sides of the lawn care vehicle <NUM>.

In the example embodiments of <FIG> and <FIG>, the riding lawn care vehicle <NUM> may also include a drive motor compartment <NUM>. The drive motor compartment <NUM> may be disposed to the rear of the operator's seat <NUM> to house various components of the riding lawn care vehicle <NUM> including an electric drive motor <NUM>. However, in other example embodiments, the drive motor compartment <NUM> could be in different positions such as in front of the seat <NUM> or below the seat <NUM>. It should be understood that in accordance with other example embodiments the motor referred to herein may be a hydraulic, air, or other types of motors known in the art.

In some embodiments, the electric drive motor <NUM> may be operably coupled to the mobility assembly <NUM> (e.g., the rear wheels <NUM>) in order to provide drive power for the riding lawn care vehicle <NUM>, as further described below. Although the electric drive motor <NUM> described herein relates to powering the rear wheels <NUM>, in other alternative embodiments, the electric drive motor <NUM> may power all four wheels <NUM>, <NUM> of the riding lawn care vehicle <NUM>. Moreover, in some cases, the electric drive motor <NUM> may manually or automatically shift between powering either two wheels <NUM>, <NUM> or all four wheels <NUM>, <NUM> of the riding lawn care vehicle <NUM>.

The riding lawn care vehicle <NUM> may also include a working assembly <NUM>. The working assembly <NUM> may be operably coupled to the electric drive motor <NUM> to perform a working function responsive at least in part to operation of the electric drive motor <NUM>. The working assembly <NUM> in this example embodiment may be a cutting deck <NUM> (see <FIG>) having at least one cutting blade mounted therein. The cutting deck <NUM> may be positioned behind the front pair of wheels <NUM> in a position to enable the operator to cut grass using the cutting blade when the cutting blade is rotated below the cutting deck <NUM> when the cutting deck <NUM> is in a cutting position. However, in some alternative examples, the cutting deck <NUM> may be positioned in front of the front pair of wheels <NUM>. In some embodiments, a footrest <NUM> may also be positioned above the cutting deck <NUM> forward of the seat <NUM> to enable the operator to rest his or her feet thereon while seated in the seat <NUM>. In embodiments that do not include the seat <NUM>, the footrest <NUM> may be the operator station from which a standing operator controls the riding lawn care vehicle <NUM>. When operating to cut grass, the grass clippings may be captured by a collection system, mulched, or expelled from the cutting deck <NUM> via either a side discharge or a rear discharge. In accordance with other example embodiments, the working assembly <NUM> could perform working functions such as snow removal, edging, tilling and/or the like.

In embodiments, where the riding lawn care vehicle <NUM> is electric powered, the riding lawn care vehicle <NUM> may also include a battery power source (not shown). The battery power source may include one or more batteries that may provide power for all electrical components of the lawn care vehicle <NUM>. In cases in which multiple batteries are combined to form the battery power source, the batteries may be distributed or located near one another. For example, three twelve volt batteries may be employed connected in series and their locations may be distributed throughout the riding lawn care vehicle <NUM>.

In an example embodiment, the electric drive motor <NUM>, the mobility assembly <NUM>, the steering assembly <NUM>, the working assembly <NUM>, the seat <NUM>, and other components of the riding lawn care vehicle <NUM> may be operably connected (directly or indirectly) to a frame <NUM> of the riding lawn care vehicle <NUM>. In this regard, the frame <NUM> may be a rigid structure configured to provide support, connectivity, and interoperability functions for various ones of the components of the riding lawn care vehicle <NUM>.

As shown in <FIG> and <FIG>, the riding lawn care vehicle <NUM> may further include a drive assembly <NUM> to provide operable coupling between the motor <NUM> and the mobility assembly <NUM>. <FIG> illustrates a perspective view of the drive assembly <NUM> in accordance with example embodiments. In this regard, the drive assembly <NUM> may transfer power from the motor <NUM> to the mobility assembly <NUM>. The drive assembly <NUM> may be or include a transmission for transferring power from the motor <NUM> to the mobility assembly <NUM>. As such, the drive assembly <NUM> may selectively provide forward drive power or reverse drive power to the mobility assembly <NUM>. More specifically, the drive assembly <NUM> may transfer rotary power from the motor <NUM> through a series of gears, frictionally engaged components, and/or the like to the wheel <NUM> to turn the wheel <NUM> in a desired direction (i.e., forward or reverse).

The drive assembly <NUM> described herein may be configured to move between a first configuration and a second configuration. In this regard, the drive assembly <NUM> may be changeable from the first configuration where the drive assembly <NUM> is in an engaged position and the second configuration where the drive assembly <NUM> is in a disengaged position.

In the first configuration when the drive assembly <NUM> is in the engaged position, the motor <NUM> may selectively provide power to the mobility assembly <NUM> (i.e., wheel <NUM>). In this regard, when the drive assembly <NUM> is in the first configuration, the drive assembly <NUM> is configured to selectively and independently provide power to the wheels <NUM> via the motor <NUM>. Furthermore, when the drive assembly <NUM> is in the first configuration, the drive assembly <NUM> may be configured to prevent the mobility assembly <NUM> or wheels <NUM> from moving when no power is being transferred from the motor <NUM> to the mobility assembly <NUM> thereby eliminating the need for a parking brake system on the riding lawn care vehicle <NUM>.

When the drive assembly <NUM> is in the second configuration, the drive assembly <NUM> may be in a disengaged position. When the drive assembly <NUM> is in the disengaged position, the motor <NUM> may be prevented from providing power to the mobility assembly <NUM>, and the mobility assembly <NUM> is configured to move or rotate in response to the user or operator pushing or towing the lawn care vehicle <NUM>. In other words, when the drive assembly <NUM> is in the first configuration, the riding lawn care vehicle <NUM> is prevented from moving, via the operator or user or otherwise, unless the motor <NUM> is providing the drive power to the mobility assembly <NUM> via the drive assembly <NUM>. However, when the drive assembly <NUM> is in the second configuration, drive power from the motor <NUM> is prevented from being transferred to the mobility assembly <NUM> and rather the operator may manually push or tow the riding lawn care vehicle <NUM>.

As noted above, the drive assembly <NUM> may be configured to receive input torque and rotational speed from the motor <NUM> for transferring to the mobility assembly <NUM> when the drive assembly <NUM> is in the first configuration (i.e., engaged position). In accordance with example embodiments, the motor <NUM> may be operably coupled or mounted directly to the drive assembly <NUM>. Furthermore, components of the mobility assembly <NUM> (e.g., wheel mounting hub <NUM>) may be operably coupled or mounted directly to the drive assembly <NUM> via an output or drive shaft <NUM>. In this regard, a length of the output shaft <NUM> may extend through the drive assembly <NUM> substantially perpendicular to a longitudinal axis <NUM> of the of the motor <NUM>. In this regard, a first end of the output shaft <NUM> may be disposed on a first side of the drive assembly <NUM> with a second, opposite end of the output shaft <NUM> being disposed on a second, opposite side of the drive assembly <NUM>. <FIG> demonstrates the output shaft <NUM> having a wheel mounting hub <NUM> for one of the rear wheels <NUM> at the first end of the output shaft <NUM> with the second end of the output shaft <NUM> being capped off via cap <NUM> and thus controlling only one of the wheels <NUM>. However, in accordance with other example embodiments, each of the first and the second end of the output shaft <NUM> may have corresponding wheel mounting hubs <NUM> for operably coupling each of the rear wheels <NUM>. Thus, references to mobility assembly <NUM> may include one or both of rear wheels <NUM>.

<FIG> illustrates a side view of the drive assembly <NUM> with a housing of the drive assembly <NUM> removed. <FIG> illustrates a perspective view of a first side of the drive assembly <NUM> with a housing of the drive assembly <NUM> removed, and <FIG> illustrate a perspective view of a second side of the drive assembly <NUM> with the housing of the driving assembly <NUM> removed. As shown in <FIG>, the drive assembly <NUM> may include a worm gear assembly <NUM> to facilitate the transfer of power from the motor <NUM> to the mobility assembly <NUM> when the drive assembly <NUM> is in the first configuration. In this regard, the worm gear assembly <NUM> may allow for single gear reduction from the motor <NUM> to the mobility assembly <NUM> to accomplish a large reduction ratio provided in the riding lawn care vehicle <NUM>.

As shown in <FIG>, the worm gear assembly <NUM> may include a worm <NUM> and a worm gear <NUM>. The worm <NUM> may be operably coupled to the motor <NUM>. In particular, the motor <NUM> may selectively transfer rotational power to the worm <NUM> in order to facilitate rotation of the worm gear <NUM> by the worm <NUM> and thereby cause rotation of the output shaft <NUM> operably coupled to components of the mobility assembly <NUM>. In this regard, when the drive assembly <NUM> is in the first configuration, the worm <NUM> and the worm gear <NUM> may be engaged. In this case, spherical threads <NUM> disposed on an exterior surface of the worm <NUM> may be configured to engage with and cause rotation of the worm gear <NUM> in response to the transfer of power from the motor <NUM>. In response to rotation of the worm gear <NUM>, the output shaft <NUM> may also rotate causing the rotational power to be transferred to respective components of the mobility assembly <NUM> (i.e., wheels <NUM>). Because a single worm gear is being used to accomplish the large reduction ratio, the drive assembly <NUM> may be used in spaces where space is limited or compact.

Even in response to the motor <NUM> not transferring power to the worm <NUM> (e.g., motor is at zero RPM), engagement of the worm <NUM> and the worm gear <NUM> may prevent any back driving of the riding lawn care vehicle <NUM> when the drive assembly <NUM> is in the first configuration. In this regard, the worm <NUM> and the worm gear <NUM> may be self-locking in that the engagement of the worm <NUM> and the worm gear <NUM> prevents the worm gear <NUM> from driving the worm <NUM>. Thus, the engagement of the worm <NUM> and the worm <NUM> effectively enables braking of the riding lawn care vehicle <NUM> without the need for the addition of a parking brake system.

The drive assembly <NUM> may also include an engagement assembly <NUM>. As noted above, the drive assembly <NUM> is moveable between a first configuration (i.e., engaged position, <FIG> and <FIG>) and a second configuration (i.e., disengaged position, <FIG>). To facilitate the drive assembly <NUM> moving between these configurations, the engagement assembly <NUM> may be provided. When the drive assembly <NUM> is in the first configuration, the engagement assembly <NUM> may be configured to lock or engage the worm gear assembly <NUM> to the output shaft <NUM> allowing the motor <NUM> to selectively provide power to the mobility assembly <NUM>. However, as noted above, when the output shaft <NUM> is engaged or locked with the worm gear assembly <NUM>, the output shaft <NUM> may be prevented from spinning freely, and thus due to the self-locking of the worm gear assembly <NUM>, movement of the mobility assembly <NUM> may be prevented unless the motor <NUM> is providing rotational power to the mobility assembly <NUM> via the drive assembly <NUM>.

The engagement assembly <NUM> may also be configured to unlock or disengage the worm gear assembly <NUM> from the output shaft <NUM>. When the worm gear assembly <NUM> is unlocked from the output shaft <NUM> as shown in <FIG>, the drive assembly <NUM> is in the second configuration (i.e., disengaged position). When the drive assembly <NUM> is in this second configuration, the output shaft <NUM> may freely spin or rotate (i.e., rotate independently) within the worm gear assembly <NUM>. Thus, when the drive assembly <NUM> is in the second configuration, the drive assembly <NUM> is prevented from providing rotational power or braking to the mobility assembly <NUM> and thus the riding lawn care vehicle <NUM> may be moved in response to being pushed or towed.

<FIG> and <FIG> illustrate a perspective view of the drive assembly <NUM> with further components of the housing of the drive assembly <NUM> removed to illustrate the components of the engagement assembly <NUM>. As shown in <FIG> and <FIG>, the engagement assembly <NUM> may include a dog clutch <NUM> and a selection lever <NUM>. The selection lever <NUM> may be pivotable or rotatable between an engaged position (<FIG>) and a disengaged position (<FIG>) to cause the unlocking or locking of the worm gear assembly <NUM> with the output shaft <NUM>. Furthermore, the position of the selection lever <NUM> may cause the engagement and disengagement of the dog clutch <NUM> with the worm gear assembly <NUM> to facilitate the unlocking or locking of the worm gear assembly <NUM> with the output shaft <NUM>.

In this regard, when the drive assembly <NUM> is in a first configuration, the dog clutch <NUM> may be engaged with or operably coupled to a side of the worm gear <NUM> (position shown in <FIG>), and when the drive assembly <NUM> is in the second configuration, the dog clutch <NUM> may be disengaged from the side of the worm gear <NUM> (position shown in <FIG>). In this regard, the dog clutch <NUM> may move between positions in response to positioning of the selection lever <NUM>. In other words, the position of the selection lever <NUM> may control the position of the dog clutch <NUM> relative to the worm gear <NUM> and thereby may cause the coupling of the worm gear assembly <NUM> to the output shaft <NUM>.

When the selection lever <NUM> is in the engaged position (position shown in <FIG>), the dog clutch <NUM> may be engaged with the worm gear <NUM> and the drive assembly <NUM> may be in the first configuration (i.e., the drive assembly <NUM> being configured to selectively transfer power from the motor <NUM> to the mobility assembly <NUM>). When the selection lever <NUM> is in the disengaged position (position shown in <FIG>), the dog clutch <NUM> may be disengaged with the worm gear <NUM> and the drive assembly <NUM> may be in the second configuration (i.e., the drive assembly <NUM> being prevented from transferring power from the motor <NUM> to the mobility assembly <NUM>).

<FIG> illustrates the dog clutch <NUM> being operably coupled to the worm gear <NUM> and thus the drive assembly <NUM> being in the first configuration. To facilitate the operably coupling of the dog clutch <NUM> to the side of the worm gear <NUM>, the engagement assembly <NUM> may also include a control fork <NUM>. As shown in <FIG>, the control fork <NUM> may enable or assist in the coupling of the dog clutch <NUM> with the worm gear <NUM>. In this regard, the control fork <NUM> may be coupled at first end <NUM> to the selection lever <NUM> and at a second end <NUM> to the dog clutch <NUM>. Thus, in response to movement of the selection lever <NUM> to the engaged position (shown in <FIG>), the control fork <NUM> may hold the dog clutch <NUM> in engagement with the worm gear <NUM> and thus the drive assembly <NUM> may be in the first configuration. However, when the selection lever <NUM> moves to the disengaged position (e.g., to a position more proximate to the worm gear <NUM> shown in <FIG>), the selection lever <NUM> may cause the shifting or movement of the control fork <NUM> toward the wheel mounting hub <NUM> and thus the dog clutch <NUM> out of engagement with the worm gear <NUM>.

In some cases, as shown in <FIG> and <FIG>, the selection lever <NUM> may include a biasing mechanism <NUM>. The biasing mechanism <NUM> may assist in urging or moving the control fork <NUM> (and thus the dog clutch <NUM>) to a position in engagement with the worm gear <NUM> (see <FIG>). In this regard, the biasing mechanism <NUM> may be operably coupled between the selection lever <NUM> and the first end <NUM> of the control fork <NUM> and may be operable to exert a biasing force on the control fork <NUM> to assist in urging the dog clutch <NUM> into engagement with the worm gear <NUM>. In an example embodiment, the biasing mechanism <NUM> may be a spring. In some cases, the spring may be a coiled spring. It should be understood, however, that in other example embodiments the biasing mechanism <NUM> may be configured to assist in urging the dog clutch <NUM> out of engagement with the worm gear <NUM>.

In some cases, the selection lever <NUM> may be manually moved by a user/operator of the riding lawn care vehicle <NUM> between the engaged and disengaged position. However, in some cases, the selection lever <NUM> may be configured to move in response to a push of a button or other some mechanism disposed at a control panel of the riding lawn care vehicle <NUM>.

In some embodiments, additional optional structures or features may be included or the structures/features described above may be modified or augmented. Each of the additional features, structures, modifications, or augmentations may be practiced in combination with the structures/features above or in combination with each other. Thus, some, all or none of the additional features, structures, modifications, or augmentations may be utilized in some embodiments, some of which may not be within the scope of the appended claims. Some example additional optional features, structures, modifications, or augmentations are described below. According to the invention, in response to the drive assembly being in the first configuration, the worm gear assembly is further configured to prevent any mobility of the mobility assembly of the vehicle in response to no power being transferred from the motor. Additionally, the drive assembly may further include an engagement assembly configured to be selectively engaged with the worm gear assembly, and the drive assembly may be movable from the first configuration to the second configuration in response to disengagement of the engagement assembly from the worm gear assembly. Alternatively or additionally, the engagement assembly may include a selection lever configured to rotate between an engaged position and a disengaged position, and the engaged position may correspond to the first configuration of the drive assembly and the disengaged position may correspond to the second configuration of the drive assembly. Alternatively or additionally, the engagement assembly may include a dog clutch. In response to the selection lever being in the engaged position, the dog clutch may be configured to engage the worm gear assembly thereby operably coupling the worm gear assembly to the shaft of the mobility assembly. In response to the selection lever being in the disengaged position, the dog clutch may be configured to be disengaged from the worm gear assembly, and the worm gear assembly may be decoupled from the shaft of the mobility assembly. Alternatively or additionally, the dog clutch may be configured to engage a side of the worm gear in response to the selection lever being in the engaged position. Alternatively or additionally, the engagement assembly may include a control fork. A first end of the control fork may be operably coupled to the selection lever, and a second end of the control fork may be operably coupled to the dog clutch. The control fork may enable the engagement of the dog clutch to the worm gear assembly in response to the selection lever being in the engaged position. Alternatively or additionally, in response to the selection lever moving to the disengaged position, the control fork may be configured to move to a position away from the worm gear assembly thereby causing the dog clutch to disengage from the worm gear assembly. Alternatively or additionally, the selection lever may include a biasing mechanism, and the biasing mechanism may be configured bias the control fork to a position toward the worm gear assembly in response to the selection lever moving to the engaged position. The lawn care vehicle may be a battery-powered lawn care vehicle.

Claim 1:
A lawn care vehicle (<NUM>) comprising:
a motor (<NUM>);
a mobility assembly (<NUM>) to provide mobility of the lawn care vehicle (<NUM>);
a working assembly (<NUM>) operably coupled to the motor (<NUM>) to perform a working function responsive at least in part to operation of the motor(<NUM>); and
a drive assembly (<NUM>) selectively coupling the motor (<NUM>) to the mobility assembly (<NUM>) to provide the mobility to the lawn care vehicle (<NUM>) responsive at least in part to operation of the motor (<NUM>), the drive assembly (<NUM>) comprising:
a worm gear assembly (<NUM>) comprising a worm (<NUM>) engaged with a worm gear (<NUM>), the worm (<NUM>) being operably coupled to the motor (<NUM>) and the worm gear (<NUM>) being selectively coupled to a shaft (<NUM>) of the mobility assembly (<NUM>);
wherein the drive assembly (<NUM>) is configured to move between a first configuration and a second configuration, wherein in response to the drive assembly (<NUM>) being in the first configuration, the worm gear assembly (<NUM>) and the shaft (<NUM>) of the mobility assembly (<NUM>) are operably coupled and the worm gear assembly (<NUM>) is configured to selectively transfer power from the motor (<NUM>) to the mobility assembly (<NUM>) to provide mobility to the lawn care vehicle (<NUM>),
wherein in response to the drive assembly (<NUM>) being in a second configuration, the worm gear assembly (<NUM>) and the shaft (<NUM>) of the mobility assembly (<NUM>) are decoupled and the worm gear assembly (<NUM>) is prevented from transferring the power from the motor (<NUM>) to the mobility assembly (<NUM>), characterized in that, in response to the drive assembly (<NUM>) being in the first configuration, the worm gear assembly (<NUM>) is further configured to prevent any mobility of the mobility assembly (<NUM>) in response to no power being transferred from the motor (<NUM>), wherein, in response to the motor (<NUM>) not transferring power to the worm (<NUM>), engagement of the worm (<NUM>) and the worm gear (<NUM>) prevent any back driving of the lawn care vehicle (<NUM>) when the drive assembly (<NUM>) is in the first configuration, wherein the worm (<NUM>) and the worm gear (<NUM>) are self-locking in that the engagement of the worm (<NUM>) and the worm gear (<NUM>) prevents the worm gear (<NUM>) from driving the worm (<NUM>).