Patent Description:
Scissor lifts commonly include a vertically movable platform that is supported by a foldable series of linked supports. The linked supports are arranged in an "X" pattern, crisscrossing with one another. A hydraulic cylinder generally controls vertical movement of the platform by engaging and rotating (i.e., unfolding) the lowermost set of linked supports, which in turn unfolds the remainder of the series of linked supports within the system. The platform raises and lowers based upon the degree of actuation by the hydraulic cylinder. A hydraulic cylinder may also control various other vehicle actions, such as, for example, steering or platform tilt functions. Scissor lifts using one or more hydraulic cylinders require an on-board reservoir tank to store hydraulic fluid for the lifting process.

<CIT> discloses a mobile scaffolding which is powered by self-contained electrical storage batteries. The electric drive is mechanically linked to the lift mechanism of the scaffolding by mechanical means comprising screw means and a mating nut means interconnected by rolling means to provide a coupling. The lift mechanism employs compact spring means biased to extend the lift mechanism from its contracted position to provide a force that supplements the electric drive when the mechanism has the most unfavorable lever moment for extension of the scaffolding. The unit has a self-contained power means for mobility and a self-contained directional control means with remote control means whereby the entire unit can be controlled from the scaffolding platform with a single lever that actuates the lift, drive and steering motors.

<CIT> discloses a system and method of controlling a scissors lift vehicle are provided. The system includes a main computer including one or more processors and one or more memory devices communicatively coupled to the one or more processors, a steer controller configured to receive commands from the main computer to control a plurality of independently steerable wheel assemblies, each wheel assembly including a steer angle sensor, a steer angle actuator, and a drive motor, and a scissors lift controller configured to control a hydraulic piston assembly including a hydraulic fluid reservoir internal to a piston rod assembly. The system also includes a tilt sensor configured to determine an angle of incline of the scissors lift vehicle, a variable-speed steer actuator configured to rotate a wheel assembly about the steer axis of rotation at a selectable rate, and a wheel including a respective drive axis of rotation.

<CIT> discloses a vehicle for work at heights having a control device for selecting a first mode to set a workbench in a horizontal state relative to a vehicle body and a second mode to set the workbench in the horizontal state relative to a horizontal surface on the ground by the switching operation. In the first mode, an actuator is operated based on the result of detection of a first angle sensor for detecting the angle θ1 of a boom to the vehicle body and a second angle sensor for detecting the angle θ2 of the workbench relative to a boom, so that the workbench is controlled to be in the horizontal state. In the second mode, the actuator is operated based on the result of detection of an inclination sensor for detecting the horizontal angle difference θ of the workbench to the horizontal surface on the ground to control the workbench to be horizontal.

One exemplary embodiment relates to a fully-electric scissor lift. The fully- electric scissor lift comprises a base, a scissor lift mechanism, a work platform, a linear actuator, and a battery. The base has a plurality of wheels. The scissor lift mechanism has a first end coupled to the base and is moveable between an extended position and a retracted position. The scissor lift mechanism comprises a foldable series of linked support members. The work platform is configured to support a load. The work platform is coupled to and supported by a second end of the scissor lift mechanism. The linear actuator is configured to selectively move the scissor lift mechanism between the extended position and the retracted position. The linear actuator has an electric lift motor. The linear actuator includes a push tube assembly including a protective outer tube and a push tube. The protective outer tube has a trunnion connection portion rotatably coupling the protective outer tube to one support member of the foldable series of linked support members. The push tube has a connection end rotatably coupling the push tube to another support member of the foldable series of linked support members. The battery is configured to apply power to the electric lift motor.

Referring to the figures generally, the various exemplary embodiments disclosed herein relate to systems, apparatuses, and methods for a fully-electric scissor lift. The scissor lift incorporates several electrically-actuated systems to control various functions of the scissor lift. For example, in some embodiments, the scissor lift may incorporate an electrically-actuated steering system and/or an electrically-actuated lift system. Accordingly, in the embodiments incorporating these electrically-actuated systems, leak-prone hydraulic systems can be entirely eliminated from the scissor lift. That is, the fully-electric scissor lift may function without the inclusion of high-pressure, leak-prone hydraulic tanks, hydraulic lines, and hydraulic fluid generally. Thus, the fully-electric scissor lift may allow for reduced maintenance and upkeep as compared to traditional hydraulic scissor lifts.

According to the exemplary embodiment depicted in <FIG> and <FIG>, a vehicle, shown as vehicle <NUM>, is illustrated. In some embodiments, the vehicle <NUM> may be fully-electric scissor lift, for example, which can be used to perform a variety of different tasks at various elevations. The vehicle <NUM> includes a base <NUM> supported by wheels 14A, 14B positioned about the base <NUM>. The vehicle <NUM> further includes a battery <NUM> positioned on board the base <NUM> of the vehicle <NUM> to supply electrical power to various operating systems present on the vehicle <NUM>.

The battery <NUM> can be a rechargeable lithium-ion battery, for example, which is capable of supplying a direct current (DC) or alternating current (AC) to vehicle <NUM> controls, motors, actuators, and the like. The battery <NUM> can include at least one input <NUM> capable of receiving electrical current to recharge the battery <NUM>. In some embodiments, the input <NUM> is a port capable of receiving a plug in electrical communication with an external power source, like a wall outlet. The battery <NUM> can be configured to receive and store electrical current from one of a traditional <NUM> V outlet, a <NUM> V outlet, a <NUM> V outlet, an electrical power generator, or another suitable electrical power source.

The vehicle <NUM> further includes a retractable lift mechanism, shown as a scissor lift mechanism <NUM>, coupled to the base <NUM>. The scissor lift mechanism <NUM> supports a work platform <NUM> (shown in <FIG>). As depicted, a first end <NUM> of the scissor lift mechanism <NUM> is anchored to the base <NUM>, while a second end <NUM> of the scissor lift mechanism <NUM> supports the work platform <NUM>. As illustrated, the scissor lift mechanism <NUM> is formed of a foldable series of linked support members <NUM>. The scissor lift mechanism <NUM> is selectively movable between a retracted or stowed position (shown in <FIG>) and a deployed or work position (shown in <FIG>) using an actuator, shown as linear actuator <NUM>. The linear actuator <NUM> is an electric actuator. The linear actuator <NUM> controls the orientation of the scissor lift mechanism <NUM> by selectively applying force to the scissor lift mechanism <NUM>. When a sufficient force is applied to the scissor lift mechanism <NUM> by the linear actuator <NUM>, the scissor lift mechanism <NUM> unfolds or otherwise deploys from the stowed, retracted position into the deployed, work position. Because the work platform <NUM> is coupled to the scissor lift mechanism <NUM>, the work platform <NUM> is also raised away from the base <NUM> in response to the deployment of the scissor lift mechanism <NUM>.

As illustrated in the exemplary embodiment provided in <FIG>, the linear actuator <NUM> includes a push tube assembly <NUM>, a gear box <NUM>, and an electric lift motor <NUM>. The push tube assembly <NUM> includes a protective outer tube <NUM> (shown in <FIG>), a push tube <NUM>, and a nut assembly <NUM> (shown in <FIG>). The protective outer tube <NUM> has a trunnion connection portion <NUM> disposed at a proximal end <NUM> thereof. The trunnion connection portion <NUM> is rigidly coupled to the gear box <NUM>, thereby rigidly coupling the protective outer tube <NUM> to the gear box <NUM>. The trunnion connection portion <NUM> is further configured to rotatably couple the protective outer tube <NUM> to one of the support members <NUM> (as shown in <FIG>).

The protective outer tube <NUM> further includes an opening at a distal end <NUM> thereof. The opening of the protective outer tube <NUM> is configured to slidably receive the push tube <NUM>. The push tube <NUM> includes a connection end <NUM> configured to rotatably couple the push tube <NUM> to another one of the support members <NUM> (as shown in <FIG>). As will be discussed below, the push tube <NUM> is slidably movable and selectively actuatable between an extended position (shown in <FIG>) and a retracted position (shown in <FIG>). The connection end <NUM> of the push tube <NUM> may similarly provide a trunnion-type connection between the push tube <NUM> and the support member <NUM>.

Referring now to <FIG>, the push tube <NUM> is rigidly coupled to the nut assembly <NUM>, such that motion of the nut assembly <NUM> results in motion of the push tube <NUM>. The push tube <NUM> and the nut assembly <NUM> envelop a central screw rod. The central screw rod is rotatably engaged with the gear box <NUM> and is configured to rotate within the push tube <NUM> and the nut assembly <NUM>, about a central axis of the push tube assembly <NUM>. The nut assembly <NUM> is configured to engage the central screw rod and translate the rotational motion of the central screw rod into translational motion of the push tube <NUM> and the nut assembly <NUM>, with respect to the central screw rod, along the central axis of the push tube assembly <NUM>. In some embodiments, the nut assembly <NUM> may be, for example, a ball screw assembly or a roller screw assembly. In some other embodiments, the nut assembly <NUM> may be any other suitable assembly for translating rotational motion of the central screw rod into translational motion of the push tube <NUM> and the nut assembly <NUM>.

Referring again to <FIG>, the lift motor <NUM> is configured to selectively provide rotational actuation to the gear box <NUM>. The rotational actuation from the lift motor <NUM> is then translated through the gear box <NUM> to selectively rotate the central screw rod of the push tube assembly <NUM>. The rotation of the central screw rod is then translated by the nut assembly <NUM> to selectively translate the push tube <NUM> and the nut assembly <NUM> along the central axis of the push tube assembly <NUM>. Accordingly, the lift motor <NUM> is configured to selectively actuate the push tube <NUM> between the extended position and the retracted position. Thus, with the trunnion connection portion <NUM> of the protective outer tube <NUM> and the connection end <NUM> of the push tube <NUM> each rotatably coupled to their respective support members <NUM>, the lift motor <NUM> is configured to selectively move the scissor lift mechanism <NUM> to various heights between and including the retracted or stowed position and the deployed or work position.

The lift motor <NUM> may be an AC motor (e.g., synchronous, asynchronous, etc.) or a DC motor (shunt, permanent magnet, series, etc.). In some instances, the lift motor <NUM> is in communication with and powered by the battery <NUM>. In some other instances, the lift motor <NUM> may receive electrical power from another electricity source on board the vehicle <NUM>.

Referring again to <FIG> and <FIG>, the battery <NUM> can also supply electrical power to a drive motor <NUM> to propel the vehicle <NUM>. The drive motor <NUM> may similarly be an AC motor (e.g., synchronous, asynchronous, etc.) or a DC motor (shunt, permanent magnet, series, etc.) for example, which receives electrical power from the battery <NUM> or another electricity source on board the vehicle <NUM> and converts the electrical power into rotational energy in a drive shaft. The drive shaft can be used to drive the wheels 14A, 14B of the vehicle <NUM> using a transmission. The transmission can receive torque from the drive shaft and subsequently transmit the received torque to a rear axle <NUM> of the vehicle <NUM>. This torque rotates the rear axle <NUM>, providing rotational motion to the rear wheels 14A and propelling the vehicle <NUM>. In some embodiments, the drive motor <NUM> may be in communication with a controller. The controller may be configured to receive input commands from a user during operation. In some embodiments, the controller may be configured to limit the drive speed of the vehicle <NUM> based on a height of the work platform <NUM>.

The rear wheels 14A of the vehicle <NUM> can be used to drive the vehicle <NUM>, while the front wheels 14B can be used to steer the vehicle <NUM>. In some embodiments, the rear wheels 14A are rigidly coupled to the rear axle <NUM>, and are held in a constant orientation relative to the base <NUM> of the vehicle <NUM> (e.g., approximately aligned with an outer perimeter <NUM> of the vehicle <NUM>). In contrast, the front wheels 14B are pivotally coupled to the base <NUM> of the vehicle <NUM>. The front wheels 14B can be coupled to vertical suspension posts <NUM>, <NUM> that are mounted to a front of the base <NUM>. The wheels 14B can be rotated relative to the base <NUM> about the vertical suspension posts <NUM>, <NUM> to adjust a direction of travel for the vehicle <NUM>.

The front wheels 14B can be oriented using a steering system <NUM>, as depicted in additional detail in <FIG>. The steering system <NUM> is an actively adjustable system that similarly operates using an electrically-powered linear actuator <NUM> in lieu of a hydraulic cylinder. The steering system <NUM> can be mounted to the underside of the base <NUM> of the vehicle <NUM>, for example, and mechanically coupled to each of the two front wheels 14B (e.g., using fasteners <NUM>). In some embodiments, the steering system <NUM> is completely contained within the outer perimeter <NUM> of the base <NUM> of the vehicle <NUM>. Accordingly, the linear actuator <NUM> can be moved to various different positions to orient the front wheels 14B of the vehicle <NUM> in a desired direction of vehicle <NUM> travel.

The linear actuator <NUM> includes a piston <NUM> movable about an axis X-X (shown in <FIG>) using a motor <NUM>. The motor <NUM> can be received within a housing <NUM> that is coupled to an underside of the base <NUM> of the vehicle <NUM>. Like the motors <NUM>, <NUM>, the motor <NUM> of the linear actuator <NUM> may be supplied with electrical power from the battery <NUM>. The motor <NUM> rotates a drive shaft contained within housing <NUM>, which in turn drives a belt or gear(s). The belt or gear can be used to transmit torque from the drive shaft to a lead screw, which rotates. Rotational motion of the lead screw drives a lead screw nut coupled to the piston <NUM>, which translates linearly about the lead screw, along the axis X-X, as the lead screw rotates. As such, the piston <NUM> can move into or out of the housing <NUM>.

The linear actuator <NUM> is coupled to a drag link <NUM> that moves in concert with the piston <NUM> of the linear actuator <NUM>. The drag link <NUM> can be an elongate bar or tube, for example, that is mounted to the piston <NUM> using a linkage <NUM>. The linkage <NUM> can be pivotally coupled to the piston <NUM> and rigidly mounted to the drag link <NUM>. In some embodiments, the linkage <NUM> is welded to the drag link <NUM> and pin-mounted to the piston <NUM>. A pin <NUM> can extend through both the linkage <NUM> and a distal end <NUM> of the piston <NUM> to secure the linkage <NUM> to the piston <NUM>.

The allowable motion of the drag link <NUM> can be governed by the piston <NUM> of the linear actuator <NUM> along with a bearing housing <NUM>. The bearing housing <NUM> can include a mounting flange <NUM> and a sleeve <NUM> extending away from the mounting flange <NUM>. The mounting flange <NUM> can include a flat surface designed to sit flush upon the underside of the base <NUM>. The mounting sleeve <NUM> can define a cylindrical passage through the bearing housing <NUM> that can receive the drag link <NUM>.

In some embodiments, the cylindrical passage is designed to form a clearance fit with the drag link <NUM>. The bearing housing <NUM> can include one or more bearings to help promote sliding movement of the drag link <NUM> through the sleeve <NUM>. Alternatively, the mounting sleeve <NUM> of the bearing housing <NUM> can include a lubricant (e.g., oil) to help promote sliding motion between the drag link <NUM> and the mounting sleeve <NUM>. One or more seals can be positioned between the drag link <NUM> and the bearing housing <NUM> to avoid lubricant leaking. In some embodiments, the drag link <NUM> and mounting sleeve <NUM> are arranged so that the drag link <NUM> translates along a second axis Y-Y (shown in <FIG>), which can be parallel to the axis X-X. The drag link <NUM> and mounting sleeve <NUM> can be approximately centered between the front wheels 14B of the vehicle <NUM>.

Each end <NUM>, <NUM> of the drag link <NUM> can include a mounting tab <NUM>, <NUM>. The mounting tabs <NUM>, <NUM> can each provide a generally flat surface surrounding a through hole <NUM>, <NUM>. The through hole <NUM>, <NUM> is adapted to receive a fastener or pin, for example, which can join the drag link <NUM> to additional components. The mounting tabs <NUM>, <NUM> can be formed integrally with the drag link <NUM> or otherwise rigidly mounted to the drag link <NUM>. In some embodiments, the mounting tabs <NUM>, <NUM> are welded to each end <NUM>, <NUM> of the drag link <NUM>. Alternatively, through holes can be formed in the drag link <NUM> near each end <NUM>, <NUM> of the drag link <NUM>, and mounting tabs <NUM>, <NUM> can be omitted.

As depicted in <FIG>, the mounting tabs <NUM>, <NUM> of the drag link <NUM> can each support a tie rod <NUM>, <NUM>. A first tie rod <NUM> is pivotally mounted to the mounting tab <NUM> on the first end <NUM> of the drag link <NUM>, while a second tie rod <NUM> is pivotally mounted to the mounting tab <NUM> on the second end <NUM> of the drag link <NUM>. Pins <NUM>, <NUM> can be used to rotatably mount a first end <NUM>, <NUM> of each of the tie rods <NUM>, <NUM> to a corresponding end <NUM>, <NUM> of the drag link <NUM>. The tie rods <NUM>, <NUM> can each be suspended below the base <NUM> of the vehicle <NUM>.

The second, opposite end <NUM>, <NUM> of each tie rod <NUM>, <NUM> can be coupled to one of the front wheels 14B of the vehicle <NUM>. Like the first end <NUM>, <NUM>, the second end <NUM>, <NUM> of the tie rod <NUM>, <NUM> can also receive a pin <NUM>, <NUM> to couple the tie rods <NUM>, <NUM> to the front wheels 14B. The pin coupling securely links the tie rod <NUM>, <NUM> to the wheel 14B, while allowing some limited rotatable motion between the front wheel 14B and the tie rod <NUM>, <NUM> it is mounted to. In some embodiments, the wheels 14B are coupled to the tie rods <NUM>, <NUM> using wheel knuckles <NUM>, <NUM>. The wheel knuckles <NUM>, <NUM> each support a front wheel 14B and are rotatably mounted to the base <NUM> of the vehicle <NUM>. The orientation of the wheel knuckles <NUM>, <NUM> controls the orientation of the front wheels 14B and, consequently, the steering of the vehicle <NUM>.

The tie rods <NUM>, <NUM> can have an arcuate shape designed to handle tensile loading. For example, each tie rod <NUM>, <NUM> can be defined by a rigid, arcing member extending angularly between about <NUM> and <NUM> degrees. As best depicted in <FIG>, each tie rod <NUM>, <NUM> is defined by an arc extending approximately <NUM> degrees between the first end <NUM>, <NUM> and the second end <NUM>, <NUM>. The arc can be defined by a constant radius or, alternatively, a variable radius. Similarly, the tie rods <NUM>, <NUM> can be defined by a uniform thickness throughout, or can vary. For example, the thickness of the tie rods <NUM>, <NUM> can increase as the distance away from each of the ends <NUM>, <NUM>, <NUM>, <NUM> increases (e.g., a point of maximum material thickness occurs near the center of each tie rod <NUM>, <NUM>). In some embodiments, the tie rods <NUM>, <NUM> have identical sizes.

The orientation of the front wheels 14B and the steering of the vehicle <NUM>, more broadly, can be controlled using the steering mechanism <NUM>. As depicted in <FIG>, the mechanical linkage formed between the linear actuator <NUM>, the drag link <NUM>, the tie bars <NUM>, <NUM>, and the wheel knuckles <NUM>, <NUM> creates an Ackerman geometry steering system <NUM> that is controlled by the linear actuator <NUM>. Specifically, the position of the piston <NUM> determines the orientation of the front wheels 14B of the vehicle <NUM>.

The linear actuator <NUM> of the steering system <NUM> is in electrical communication with both the battery <NUM> and a vehicle controller <NUM> configured to receive and execute steering commands. In some embodiments, the linear actuator <NUM> is hardwired to both the battery <NUM> and the vehicle controller <NUM>. In some other embodiments, the linear actuator <NUM> may be in wireless communication (e.g., Bluetooth, internet, cloud-based communication system, etc.). When the vehicle controller <NUM> receives a steering command (e.g., a desired steering orientation from a user through a steering wheel or joystick), the vehicle controller <NUM> can first determine the current orientation of the front wheels 14B. The current orientation of the front wheels 14B is determined by detecting (e.g., using a sensor or encoder) or otherwise knowing the current position of the piston <NUM> of the linear actuator <NUM>. If the desired steering orientation does not match the current orientation of the front wheels 14B, the vehicle controller <NUM> can issue a command to the motor <NUM> of the linear actuator <NUM> to either retract or further advance the piston <NUM> relative to the housing <NUM>. In some other embodiments, the steering system <NUM> and vehicle controller <NUM> respond to a command from a user (e.g., through a steering wheel or joystick) by adjusting the linear actuator <NUM> without using or needing current front wheel 14B orientation information.

The rotatable coupling formed between the wheel knuckles <NUM>, <NUM>, the tie rods <NUM>, <NUM>, and the drag link <NUM> rotates the front wheels 14B in response to lateral movement by the drag link <NUM>. As shown in <FIG>, the second end <NUM>, <NUM> of each tie rod <NUM>, <NUM> is eccentrically coupled to a wheel knuckle <NUM>, <NUM>, offset from a rotation point <NUM>, <NUM> for the wheel knuckle <NUM>, <NUM>. The tie rods <NUM>, <NUM> can be pivotally coupled to a flange <NUM>, <NUM> of the wheel knuckle <NUM>, <NUM> that extends forward from the rotation point <NUM>, <NUM> (when the front wheels 14B are oriented straight forward).

Due to the eccentric mounting of the tie rods <NUM>, <NUM> to the flanges <NUM>, <NUM>, movement of the drag link <NUM> creates a torque on each wheel knuckle <NUM>, <NUM> sufficient to rotate the wheel knuckles <NUM>, <NUM> about their respective rotation points <NUM>, <NUM>. Rotation of the wheel knuckle <NUM>, <NUM> about the rotation points <NUM>, <NUM> rotates the front wheels 14B about the vertical suspension posts <NUM>, <NUM>, and changes the steering orientation of the vehicle <NUM>. Since the rear wheels 14A are fixed in a forward-aligned orientation relative to the base <NUM> of the vehicle <NUM>, rotating the front wheels 14B causes the vehicle <NUM> to turn in the direction the front wheels 14B are pointed.

In some embodiments, the steering system <NUM> can be alternatively incorporated into the rear wheels 14A of the vehicle <NUM>, rather than the front wheels 14B. In some other embodiments, a steering system similar to the steering system <NUM> may be incorporated into both the front wheels 14B and the rear wheels 14A to provide additional vehicle movement capabilities, as desired for a given application.

As shown in <FIG>, the vehicle controller <NUM> is in further communication with a lift motor controller <NUM>. The lift motor controller <NUM> is in communication with the linear actuator <NUM> (e.g., the lift motor <NUM>) to control the movement of the scissor lift mechanism <NUM>. Communication between the lift motor controller <NUM> and the linear actuator <NUM> and/or between the vehicle controller <NUM> and the lift motor controller <NUM> can be provided through a hardwired connection, or through a wireless connection (e.g., Bluetooth, Internet, cloud-based communication system, etc.). It should be understood that each of the vehicle controller <NUM> and the lift controller <NUM> includes various processing and memory components configured to perform the various activities and methods described herein. For example, in some instances, each of the vehicle controller <NUM> and the lift controller <NUM> includes a processing circuit having a processor and a memory. The memory is configured to store various instructions configured to, when executed by the processor, cause the vehicle <NUM> to perform the various activities and methods described herein.

In some embodiments, the vehicle controller <NUM> may be configured to limit the drive speed of the vehicle <NUM> depending on a height of the work platform <NUM>. That is, the lift motor controller <NUM> may be in communication with a support member angle sensor, such as scissor angle sensor <NUM> (shown in <FIG>), configured to monitor a lift angle of the bottom-most support member <NUM> with respect to the base <NUM>. Based on the lift angle and the configuration of the scissor lift mechanism <NUM>, the lift controller <NUM> may determine the current height of the work platform <NUM>. Using this height, the vehicle controller <NUM> may be configured to limit or proportionally reduce the drive speed of the vehicle <NUM> as the work platform <NUM> is raised.

It should be appreciated that, while the retractable lift mechanism included on vehicle <NUM> is a scissor lift mechanism, in some instances, a vehicle may be provided that alternatively includes a retractable lift mechanism in the form of a boom lift mechanism. For example, in the exemplary embodiment depicted in <FIG>, a vehicle, shown as vehicle <NUM>, is illustrated. The vehicle <NUM> includes a retractable lift mechanism, shown as boom lift mechanism <NUM>. The boom lift mechanism <NUM> is similarly formed of a foldable series of linked support members <NUM>. The boom lift mechanism <NUM> is selectively movable between a retracted or stowed position and a deployed or work position using a plurality of actuators <NUM>. Each of the plurality of actuators <NUM> is similarly an electric actuator.

It should be further appreciated that the electric actuators used in the lift mechanisms <NUM>, <NUM>, as well as in the steering system <NUM>, may be incorporated into nearly any type of electric vehicle. For example, the electric systems described herein can be incorporated into, for example, a scissor lift, an articulated boom, a telescopic boom, or any other type of aerial work platform vehicle.

Advantageously, vehicles <NUM>, <NUM> are fully-electric lift devices. All of the electric actuators and electric motors of vehicles <NUM>, <NUM> can be configured to perform their respective operations without requiring any hydraulic systems, hydraulic reservoir tanks, hydraulic fluids, engine systems, etc. That is, both vehicles <NUM>, <NUM> are completely devoid of any hydraulic systems and/or hydraulic fluids generally. Said differently, both vehicles <NUM>, <NUM> are devoid of any moving fluids. Traditional lift devices do not use a fully-electric system and require regular maintenance to ensure that the various hydraulic systems are operating properly. As such, the vehicles <NUM>, <NUM> use electric motors and electric actuators, which allows for the absence of combustible fuels (e.g., gasoline, diesel) and/or hydraulic fluids. The vehicles <NUM>, <NUM> are powered by batteries, such as battery <NUM>, that can be re-charged when necessary.

Although this description may discuss a specific order of method steps, the order of the steps may differ from what is outlined. Also two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.

As utilized herein, the terms "approximately", "about", "substantially", and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

The terms "coupled," "connected," and the like, as used herein, mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent, etc.) or moveable (e.g., removable, releasable, etc.). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

References herein to the positions of elements (e.g., "top," "bottom," "above," "below," "between," etc.) are merely used to describe the orientation of various elements in the figures.

Claim 1:
A fully-electric scissor lift (<NUM>) comprising:
a base (<NUM>) having a plurality of wheels (14A, 14B);
a scissor lift mechanism (<NUM>) having a first end (<NUM>) coupled to the base (<NUM>) and being moveable between an extended position and a retracted position, the scissor lift mechanism (<NUM>) comprising a foldable series of linked support members (<NUM>);
a work platform (<NUM>) configured to support a load, the work platform (<NUM>) being coupled to and supported by a second end (<NUM>) of the scissor lift mechanism (<NUM>);
a linear actuator (<NUM>) configured to selectively move the scissor lift mechanism (<NUM>) between the extended position and the retracted position, the linear actuator (<NUM>) having an electric lift motor (<NUM>), the linear actuator (<NUM>) including a push tube assembly (<NUM>) including a protective outer tube (<NUM>) and a push tube (<NUM>), the protective outer tube (<NUM>) having a trunnion connection portion (<NUM>) rotatably coupling the protective outer tube (<NUM>) to one support member of the foldable series of linked support members (<NUM>), the push tube (<NUM>) having a connection end (<NUM>) rotatably coupling the push tube (<NUM>) to another support member of the foldable series of linked support members (<NUM>); and
a battery (<NUM>) configured to apply power to the electric lift motor (<NUM>).