Patent Description:
Power machines, for the purposes of this disclosure, include any type of machine that generates power for the purpose of accomplishing a particular task or a variety of tasks. One type of power machine is a work vehicle. Work vehicles, such as loaders, are generally self-propelled vehicles that have a work device, such as a lift arm (although some work vehicles can have other work devices) that can be manipulated to perform a work function. Work vehicles include loaders, excavators, utility vehicles, tractors, and trenchers, to name a few examples.

Many power machines have operator compartments defined, at least in part, by a cab in which an operator can sit while operating the power machine. Some of these cabs have doors that can be opened to allow access into and out of the cab and can be closed to provide protection from the elements and the like when an operator is located within the cab. Some loaders with front door entry have lift arms that move in front of the cab such that the door must be closed while operating the power machine otherwise the door, in the open position, will interfere with the travel path of the lift arm.

<CIT> discloses a cabin unit for a work machine that comprises a cabin frame including a ceiling frame forming a top portion of the cabin frame, and a door open frame forming a front portion of the cabin frame, a door provided in the door open frame, a door opening/closing mechanism for supporting the door from the door open from to the ceiling frame to be moved rearward and upward from a closed position for closing the door to an open position in which a front surface of the door in the closed position is directed upward, a locking mechanism provided above the door for limiting movement of the door when in the closed position or the open position, and a first unlocking mechanism provided in the door for unlocking the locking mechanism.

<CIT> discloses an operator cab for a skid steer vehicle is equipped with an inwardly folding front access door that can be locked in either a fully closed position or a fully open position. A pair of over-centered cylinders assists with closing and opening of the front access door. A lever, located in the operator cab, may be used to unlock the door from either its fully open position or its fully closed position.

According to the invention, a cab for a power invention as recited in the independent claim is provided. The dependent claims define preferred embodiments.

Disclosed are cabs, and power machines with cabs that have a door that is moveable between opened and closed positions. In some exemplary embodiments, in the opened position, the door is positioned within an operator compartment of the cab above the operator seat and below a top of the cab. Various linkage configurations including a four-bar linkage attaches the door to the cab and defines the travel path of the door between closed and opened positions. The linkage configurations are advantageously designed to minimize interference with operator visibility and maintain sufficient head room when the door is in an opened position.

A cab for a power machine comprises a frame having first and second side walls, a top portion, a front portion having a door opening for cab ingress and egress, and a rear portion. A cab door is configured to be positioned in the door opening when in a fully closed position. An operator seat having a seat back is positioned in the cab, along with a joystick controller positioned forward of the operator seat. A linkage configuration includes portions of the first side wall, the door, and first and second links each pivotally coupled to the first side wall and to the door. The linkage configuration is adapted to support the door and define a path between fully closed and fully opened positions. In the fully opened position, the door may extend beyond a rear wall that defines an operator compartment.

In some embodiments, each of the first and second links comprises two link sections oriented at an obtuse angle relative to each other such that the first and second links are substantially masked by a cab structure when the door is in the fully closed position.

In some embodiments, the pivotal connection of the first link to the first side wall is positioned below the operator seat and rearward of the seat back.

In some embodiments, the pivotal connection of the second link to the first side wall is positioned vertically near a horizontal reinforcing member of the first side wall and below a horizontal center line of the first side wall.

In some embodiments, the linkage and door are configured such that when the door is in the fully opened position, the door is positioned below the top portion of the frame and extends through an opening of the rear portion of the frame and into a cover that is attached to the cab.

These and other features of the disclosed cabs and power machines are described in detail below. The above described and other features of the various disclosed embodiments can be included in differing combinations.

The concepts disclosed in this discussion are described and illustrated by referring to illustrative embodiments. These concepts, however, are not limited in their application to the details of construction and the arrangement of components in the illustrative embodiments and are capable of being practiced or being carried out in various other ways. The terminology in this document is used for description and should not be regarded as limiting. Words such as "including," "comprising," and "having" and variations thereof as used herein are meant to encompass the items listed thereafter, equivalents thereof, as well as additional items.

Disclosed are cabs, and power machines with cabs, having doors that are moveable between opened and closed positions. In some illustrative embodiments, the door is positioned within an operator compartment of the cab above the operator seat and below a top of the cab when in the opened position. In some embodiments, a linkage configuration attaches the door to the cab and defines the travel path of the door between the closed and opened positions. In some of these embodiments, the linkage configuration is a four-bar linkage that includes links that are shaped to minimize interference with operator visibility. These and other features of the disclosed cabs and power machines are described in detail below.

These concepts can be practiced on various power machines, as will be described below. A representative power machine on which the embodiments can be practiced is illustrated in diagram form in <FIG> and one example of such a power machine is illustrated in <FIG> and described below before any embodiments are disclosed. For the sake of brevity, only one power machine is illustrated and discussed as being a representative power machine. However, as mentioned above, the embodiments below can be practiced on any of several power machines, including power machines of different types from the representative power machine shown in <FIG>. Power machines, for the purposes of this discussion, include a frame, at least one work element, and a power source that can provide power to the work element to accomplish a work task. One type of power machine is a self-propelled work vehicle. Self-propelled work vehicles are a class of power machines that include a frame, work element, and a power source that can provide power to the work element. At least one of the work elements is a motive system for moving the power machine under power.

<FIG> is a block diagram that illustrates the basic systems of a power machine <NUM>, which can be any of a number of different types of power machines, upon which the embodiments discussed below can be advantageously incorporated. The block diagram of <FIG> identifies various systems on power machine <NUM> and the relationship between various components and systems. As mentioned above, at the most basic level, power machines for the purposes of this discussion include a frame, a power source, and a work element. The power machine <NUM> has a frame <NUM>, a power source <NUM>, and a work element <NUM>. Because power machine <NUM> shown in <FIG> is a self-propelled work vehicle, it also has tractive elements <NUM>, which are themselves work elements provided to move the power machine over a support surface and an operator station <NUM> that provides an operating position for controlling the work elements of the power machine. A control system <NUM> is provided to interact with the other systems to perform various work tasks at least in part in response to control signals provided by an operator.

Certain work vehicles have work elements that can perform a dedicated task. For example, some work vehicles have a lift arm to which an implement such as a bucket is attached such as by a pinning arrangement. The work element, i.e., the lift arm can be manipulated to position the implement for performing the task. The implement, in some instances can be positioned relative to the work element, such as by rotating a bucket relative to a lift arm, to further position the implement. Under normal operation of such a work vehicle, the bucket is intended to be attached and under use. Such work vehicles may be able to accept other implements by disassembling the implement/work element combination and reassembling another implement in place of the original bucket. Other work vehicles, however, are intended to be used with a wide variety of implements and have an implement interface such as implement interface <NUM> shown in <FIG>. At its most basic, implement interface <NUM> is a connection mechanism between the frame <NUM> or a work element <NUM> and an implement, which can be as simple as a connection point for attaching an implement directly to the frame <NUM> or a work element <NUM> or more complex, as discussed below.

On some power machines, implement interface <NUM> can include an implement carrier, which is a physical structure movably attached to a work element. The implement carrier has engagement features and locking features to accept and secure any of several implements to the work element. One characteristic of such an implement carrier is that once an implement is attached to it, it is fixed to the implement (i.e. not movable with respect to the implement) and when the implement carrier is moved with respect to the work element, the implement moves with the implement carrier. The term implement carrier as used herein is not merely a pivotal connection point, but rather a dedicated device specifically intended to accept and be secured to various implements. The implement carrier itself is mountable to a work element <NUM> such as a lift arm or the frame <NUM>. Implement interface <NUM> can also include one or more power sources for providing power to one or more work elements on an implement. Some power machines can have a plurality of work element with implement interfaces, each of which may, but need not, have an implement carrier for receiving implements. Some other power machines can have a work element with a plurality of implement interfaces so that a single work element can accept a plurality of implements simultaneously. Each of these implement interfaces can, but need not, have an implement carrier.

Frame <NUM> includes a physical structure that can support various other components that are attached thereto or positioned thereon. The frame <NUM> can include any number of individual components. Some power machines have frames that are rigid. That is, no part of the frame is movable with respect to another part of the frame. Other power machines have at least one portion that can move with respect to another portion of the frame. For example, excavators can have an upper frame portion that rotates with respect to a lower frame portion. Other work vehicles have articulated frames such that one portion of the frame pivots with respect to another portion for accomplishing steering functions.

Frame <NUM> supports the power source <NUM>, which is configured to provide power to one or more work elements <NUM> including the one or more tractive elements <NUM>, as well as, in some instances, providing power for use by an attached implement via implement interface <NUM>. Power from the power source <NUM> can be provided directly to any of the work elements <NUM>, tractive elements <NUM>, and implement interfaces <NUM>. Alternatively, power from the power source <NUM> can be provided to a control system <NUM>, which in turn selectively provides power to the elements that capable of using it to perform a work function. Power sources for power machines typically include an engine such as an internal combustion engine and a power conversion system such as a mechanical transmission or a hydraulic system that is configured to convert the output from an engine into a form of power that is usable by a work element. Other types of power sources can be incorporated into power machines, including electrical sources or a combination of power sources, known generally as hybrid power sources.

<FIG> shows a single work element designated as work element <NUM>, but various power machines can have any number of work elements. Work elements are typically attached to the frame of the power machine and movable with respect to the frame when performing a work task. In addition, tractive elements <NUM> are a special case of work element in that their work function is generally to move the power machine <NUM> over a support surface. Tractive elements <NUM> are shown separate from the work element <NUM> because many power machines have additional work elements besides tractive elements, although that is not always the case. Power machines can have any number of tractive elements, some or all of which can receive power from the power source <NUM> to propel the power machine <NUM>. Tractive elements can be, for example, track assemblies, wheels attached to an axle, and the like. Tractive elements can be mounted to the frame such that movement of the tractive element is limited to rotation about an axle (so that steering is accomplished by a skidding action) or, alternatively, pivotally mounted to the frame to accomplish steering by pivoting the tractive element with respect to the frame. Power machine <NUM> includes an operator station <NUM> that includes an operating position from which an operator can control operation of the power machine. In some power machines, the operator station <NUM> is defined by an enclosed or partially enclosed cab.

<FIG> illustrate a loader <NUM>, which is one particular example of a power machine of the type illustrated in <FIG> where the embodiments discussed below can be advantageously employed. Loader <NUM> is a skid-steer loader, which is a loader that has tractive elements (in this case, four wheels) that are mounted to the frame of the loader via rigid axles. Here the phrase "rigid axles" refers to the fact that the skid-steer loader <NUM> does not have any tractive elements that can be rotated or steered to help the loader accomplish a turn. Instead, a skid-steer loader has a drive system that independently powers one or more tractive elements on each side of the loader so that by providing differing tractive signals to each side, the machine will tend to skid over a support surface. These varying signals can even include powering tractive element(s) on one side of the loader to move the loader in a forward direction and powering tractive element(s) on another side of the loader to mode the loader in a reverse direction so that the loader will turn about a radius centered within the footprint of the loader itself. The term "skid-steer" has traditionally referred to loaders that have skid steering as described above with wheels as tractive elements. However, it should be noted that many track loaders also accomplish turns via skidding and are technically skid-steer loaders, even though they do not have wheels. For the purposes of this discussion, unless noted otherwise, the term skid-steer should not be seen as limiting the scope of the discussion to those loaders with wheels as tractive elements.

Loader <NUM> is one particular example of the power machine <NUM> illustrated broadly in <FIG> and discussed above. To that end, features of loader <NUM> described below include reference numbers that are generally similar to those used in <FIG>. For example, loader <NUM> is described as having a frame <NUM>, just as power machine <NUM> has a frame <NUM>. The loader <NUM> should not be considered limiting especially as to the description of features that loader <NUM> may have described herein that are not essential to the disclosed embodiments and thus may or may not be included in power machines other than loader <NUM> upon which the embodiments disclosed below may be advantageously practiced. Unless specifically noted otherwise, embodiments disclosed below can be practiced on a variety of power machines, with the loader <NUM> being only one of those power machines. For example, some or all of the concepts discussed below can be practiced on many other types of work vehicles such as various other loaders, excavators, trenchers, and dozers, to name but a few examples.

Loader <NUM> includes frame <NUM> that supports a power system <NUM>, the power system can generate or otherwise providing power for operating various functions on the power machine. Power system <NUM> is shown in block diagram form, but is located within the frame <NUM>. Frame <NUM> also supports a work element in the form of a lift arm assembly <NUM> that is powered by the power system <NUM> and can perform various work tasks. As loader <NUM> is a work vehicle, frame <NUM> also supports a traction system <NUM>, which is also powered by power system <NUM> and can propel the power machine over a support surface. The lift arm assembly <NUM> in turn supports an implement interface <NUM>, which includes an implement carrier <NUM> that can receive and securing various implements to the loader <NUM> for performing various work tasks and power couplers <NUM>, to which an implement can be coupled for selectively providing power to an implement that might be connected to the loader. Power couplers <NUM> can provide sources of hydraulic or electric power or both. The loader <NUM> includes a cab <NUM> that defines an operator station <NUM> from which an operator can manipulate various control devices <NUM> to cause the power machine to perform various work functions. Cab <NUM> is accessible from an opening in the front of the cab. Although not shown in <FIG>, in many instances, a door is provided to cover the opening and is positionable between a closed and an opened position. Many of these doors are pivotally mounted about a vertical axis so that door pivots outward from the door when in the opened position. When the door is in the opened position, it is necessary for the lift arm <NUM> (as discussed below) to be in in the lowered position because the door would otherwise interfere with the lift arm or components on the lift arm, specifically tilt cylinder actuators. Cab <NUM> can be pivoted back about an axis that extends through mounts <NUM> to provide access to power system components as needed for maintenance and repair. Access to power system components can also be provided by opening a tailgate <NUM> that is pivotally mounted to the frame <NUM> of the power machine at a rear end thereof.

The operator station <NUM> includes an operator seat <NUM> and a plurality of operation input devices, including control levers <NUM> that an operator can manipulate to control various machine functions. Operator input devices can include buttons, switches, levers, sliders, pedals and the like that can be stand-alone devices such as hand operated levers or foot pedals or incorporated into hand grips or display panels, including programmable input devices. Actuation of operator input devices can generate signals in the form of electrical signals, hydraulic signals, and/or mechanical signals. Signals generated in response to operator input devices are provided to various components on the power machine for controlling various functions on the power machine. Among the functions that are controlled via operator input devices on power machine <NUM> include control of the tractive elements <NUM>, the lift arm assembly <NUM>, the implement carrier <NUM>, and providing signals to any implement that may be operably coupled to the implement.

Loaders can include human-machine interfaces including display devices that are provided in the cab <NUM> to give indications of information relatable to the operation of the power machines in a form that can be sensed by an operator, such as, for example audible and/or visual indications. Audible indications can be made in the form of buzzers, bells, and the like or via verbal communication. Visual indications can be made in the form of graphs, lights, icons, gauges, alphanumeric characters, and the like. Displays can be dedicated to provide dedicated indications, such as warning lights or gauges, or dynamic to provide programmable information, including programmable display devices such as monitors of various sizes and capabilities. Display devices can provide diagnostic information, troubleshooting information, instructional information, and various other types of information that assists an operator with operation of the power machine or an implement coupled to the power machine. Other information that may be useful for an operator can also be provided. Other power machines, such walk behind loaders may not have a cab nor an operator compartment, nor a seat. The operator position on such loaders is generally defined relative to a position where an operator is best suited to manipulate operator input devices.

Various power machines that can include and/or interacting with the embodiments discussed below can have various frame components that support various work elements. The elements of frame <NUM> discussed herein are provided for illustrative purposes and frame <NUM> is not the only type of frame that a power machine on which the embodiments can be practiced can employ. Frame <NUM> of loader <NUM> includes an undercarriage or lower portion <NUM> of the frame and a mainframe or upper portion <NUM> of the frame that is supported by the undercarriage. The mainframe <NUM> of loader <NUM>, in some embodiments is attached to the undercarriage <NUM> such as with fasteners or by welding the undercarriage to the mainframe. Alternatively, the mainframe and undercarriage can be integrally formed. Mainframe <NUM> includes a pair of upright portions 214A and 214B located on either side and toward the rear of the mainframe that support lift arm assembly <NUM> and to which the lift arm assembly <NUM> is pivotally attached. The lift arm assembly <NUM> is illustratively pinned to each of the upright portions 214A and 214B. The combination of mounting features on the upright portions 214A and 214B and the lift arm assembly <NUM> and mounting hardware (including pins used to pin the lift arm assembly to the mainframe <NUM>) are collectively referred to as joints 216A and 216B (one is located on each of the upright portions <NUM>) for the purposes of this discussion. Joints 216A and 216B are aligned along an axis <NUM> so that the lift arm assembly is capable of pivoting, as discussed below, with respect to the frame <NUM> about axis <NUM>. Other power machines may not include upright portions on either side of the frame, or may not have a lift arm assembly that is mountable to upright portions on either side and toward the rear of the frame. For example, some power machines may have a single arm, mounted to a single side of the power machine or to a front or rear end of the power machine. Other machines can have a plurality of work elements, including a plurality of lift arms, each of which is mounted to the machine in its own configuration. Frame <NUM> also supports a pair of tractive elements in the form of wheels 219A-D on either side of the loader <NUM>.

The lift arm assembly <NUM> shown in <FIG> is one example of many different types of lift arm assemblies that can be attached to a power machine such as loader <NUM> or other power machines on which embodiments of the present discussion can be practiced. The lift arm assembly <NUM> is what is known as a vertical lift arm, meaning that the lift arm assembly <NUM> is moveable (i.e. the lift arm assembly can be raised and lowered) under control of the loader <NUM> with respect to the frame <NUM> along a lift path <NUM> that forms a generally vertical path. Other lift arm assemblies can have different geometries and can be coupled to the frame of a loader in various ways to provide lift paths that differ from the radial path of lift arm assembly <NUM>. For example, some lift paths on other loaders provide a radial lift path. Other lift arm assemblies can have an extendable or telescoping portion. Other power machines can have a plurality of lift arm assemblies attached to their frames, with each lift arm assembly being independent of the other(s). Unless specifically stated otherwise, none of the inventive concepts set forth in this discussion are limited by the type or number of lift arm assemblies that are coupled to a particular power machine.

As referred to briefly above, the lift arm assembly <NUM> has a pair of lift arms <NUM> that are disposed on opposing sides of the frame <NUM>. A first end of each of the lift arms <NUM> is pivotally coupled to the power machine at joints <NUM> and a second end 232B of each of the lift arms is positioned forward of the frame <NUM> when in a lowered position as shown in <FIG>. Joints <NUM> are located toward a rear of the loader <NUM> so that the lift arms extend along the sides of the frame <NUM>. The lift path <NUM> is defined by the path of travel of the second end 232B of the lift arms <NUM> as the lift arm assembly <NUM> is moved between a minimum and maximum height.

Each of the lift arms <NUM> has a first portion 234A of each lift arm <NUM> is pivotally coupled to the frame <NUM> at one of the joints <NUM> and the second portion 234B extends from its connection to the first portion 234A to the second end 232B of the lift arm assembly <NUM>. The first portions 234A of the lift arms <NUM> are each coupled to each other via a cross member <NUM>. Cross member <NUM> provides increased structural stability to the lift arm assembly <NUM>. The second portions 234B via a cross member <NUM> that is attached to each of the second portions of the lift arms 234B. Cross member <NUM> provides increased structural stability to the lift arm assembly <NUM>.

A pair of actuators <NUM>, which on loader <NUM> are hydraulic cylinders configured to receive pressurized fluid from power system <NUM>, are pivotally coupled to both the frame <NUM> and the lift arms <NUM> at pivotable joints 238A and 238B, respectively, on either side of the loader <NUM>. The actuators <NUM> are sometimes referred to individually and collectively as lift cylinders. Actuation (i.e., extension and retraction) of the actuators <NUM> cause the lift arm assembly <NUM> to pivot about joints <NUM> and thereby be raised and lowered along a fixed path illustrated by arrow <NUM>. Each of a pair of control links <NUM> are pivotally mounted to the frame <NUM> and one of the lift arms <NUM> on either side of the frame <NUM>. The control links <NUM> help to define the fixed lift path of the lift arm assembly <NUM>.

Some lift arms, most notably lift arms on excavators but also possible on loaders, may have portions that are controllable to pivot with respect to another segment instead of moving in concert (i.e. along a pre-determined path) as is the case in the lift arm assembly <NUM> shown in <FIG>. Some power machines have lift arm assemblies with a single lift arm, such as is known in excavators or even some loaders and other power machines. Other power machines can have a plurality of lift arm assemblies, each being independent of the other(s).

An implement interface <NUM> is provided proximal to a second end 232B of the lift arm assembly <NUM>. The implement interface <NUM> includes an implement carrier <NUM> that can accept and securing a variety of different implements to the lift arm <NUM>. Such implements have a complementary machine interface that is configured to be engaged with the implement carrier <NUM>. The implement carrier <NUM> is pivotally mounted at the second end 232B of the arm <NUM>. Implement carrier actuators <NUM> are operably coupled the lift arm assembly <NUM> and the implement carrier <NUM> and are operable to rotate the implement carrier with respect to the lift arm assembly. Implement carrier actuators <NUM> are illustratively hydraulic cylinders and often known as tilt cylinders.

By having an implement carrier capable of being attached to a plurality of different implements, changing from one implement to another can be accomplished with relative ease. For example, machines with implement carriers can provide an actuator between the implement carrier and the lift arm assembly, so that removing or attaching an implement does not involve removing or attaching an actuator from the implement or removing or attaching the implement from the lift arm assembly. The implement carrier <NUM> provides a mounting structure for easily attaching an implement to the lift arm (or other portion of a power machine) that a lift arm assembly without an implement carrier does not have.

Some power machines can have implements or implement like devices attached to it such as by being pinned to a lift arm with a tilt actuator also coupled directly to the implement or implement type structure. A common example of such an implement that is rotatably pinned to a lift arm is a bucket, with one or more tilt cylinders being attached to a bracket that is fixed directly onto the bucket such as by welding or with fasteners. Such a power machine does not have an implement carrier, but rather has a direct connection between a lift arm and an implement.

The implement interface <NUM> also includes an implement power source <NUM> available for connection to an implement on the lift arm assembly <NUM>. The implement power source <NUM> includes pressurized hydraulic fluid port to which an implement can be removably coupled. The pressurized hydraulic fluid port selectively provides pressurized hydraulic fluid for powering one or more functions or actuators on an implement. The implement power source can also include an electrical power source for powering electrical actuators and/or an electronic controller on an implement. The implement power source <NUM> also exemplarily includes electrical conduits that are in communication with a data bus on the excavator <NUM> to allow communication between a controller on an implement and electronic devices on the loader <NUM>.

The description of power machine <NUM> and loader <NUM> above is provided for illustrative purposes, to provide illustrative environments on which the embodiments discussed below can be practiced. While the embodiments discussed can be practiced on a power machine such as is generally described by the power machine <NUM> shown in the block diagram of <FIG> and more particularly on a loader such as loader <NUM>, unless otherwise noted or recited, the concepts discussed below are not intended to be limited in their application to the environments specifically described above.

<FIG> and <FIG> are side and perspective view illustrations of a cab <NUM> providing an operator compartment or station <NUM> according to one illustrative embodiment. Cab <NUM> is generally similar to the cab <NUM> and provides an operator station such as operator station <NUM> discussed above. Cab <NUM> provides an improved structure which allows a door to be moved between closed and opened positions in a manner which provides an operator better cab ingress and egress, prevents door interference with a lift arm structure, and minimizes interference with operator visibility. Other benefits of some disclosed embodiments will also be apparent in the following disclosure.

Cab <NUM> has a cab frame <NUM> having first and second side walls <NUM> and <NUM>, a front <NUM>, a rear <NUM>, a top <NUM>, and a bottom <NUM>. A seat <NUM> is supported on the bottom of the cab frame. The cab frame <NUM> also defines a lower portion <NUM> where an operator can position feet during machine operation. In <FIG> and <FIG>, a cab door <NUM> is in a closed position at the front of the operator compartment <NUM> covering an opening <NUM> in front portion <NUM> of frame <NUM>. <FIG> and <FIG> illustrate cab door <NUM> in a partially open position, and <FIG> and <FIG> illustrate cab door <NUM> in a fully open position. Cab door <NUM> includes, in some embodiments, a cover portion <NUM> which at least partially covers and/or forms a part of, lower portion <NUM> when door <NUM> is in the illustrated closed position. In some exemplary embodiments, cover <NUM> is raised and lowered with door <NUM>. Thus, when door <NUM> is raised to the open position shown in <FIG> and <FIG>, the opening <NUM> through which the operator moves into and out of the cab is enlarged to provide improved ingress and egress. The cover portion <NUM> is shown as extending beyond top <NUM> in the opened position, but in some embodiments, the cover portion does not extend beyond the top <NUM>.

In some exemplary embodiments, a linkage <NUM> is provided on each of first and second sides <NUM> and <NUM> to couple door <NUM> to frame <NUM> and to control movement of the door between closed and open positions along a configured path. The linkage <NUM> shown in <FIG> is a four-bar linkage arrangement that includes a first link <NUM> and a second link <NUM> each of which are pivotally attached to the frame <NUM> and the door <NUM>. Portions of the frame <NUM> between attachment points of links <NUM> and <NUM> to the frame acts as the third link of the four-bar linkage. The portion of the door <NUM> between the connection points provides the fourth link of the four-bar linkage <NUM>. In exemplary embodiments, four-bar linkage <NUM> includes features which provide a movement path for door <NUM> such that, when moved to a fully open position (shown in <FIG> and <FIG>), door <NUM> is positioned horizontally above the operator's head, but inside of the cab. Thus, in the fully opened position, door <NUM> extends at least partially horizontally beneath top frame portion <NUM> as is discussed below in greater detail. While raising door <NUM> along the movement path provided by four-bar linkage <NUM>, door <NUM> extends beyond a front plane (represented by dashed line <NUM>) of cab <NUM> as shown <FIG>, but does not interfere with any lift arm of the power machine. Alternatively, the door can be positioned so that it does not extend beyond a front plane of the cab <NUM>.

In the illustrated embodiment, first link <NUM> of the four-bar linkage has a first pivot connection <NUM> to the frame <NUM> configured to allow link <NUM> to rotate relative to frame <NUM>. Link <NUM> also has a second pivot connection <NUM>, to door <NUM>, which is better shown in the partially open-door position of <FIG> and <FIG>. Second pivot connection <NUM> is configured to allow link <NUM> and door <NUM> to pivot relative to one another. In some exemplary embodiments, first link <NUM> includes at least a first link section <NUM> and a second link section <NUM>, which are best shown in <FIG>. Link sections <NUM> and <NUM> of first link <NUM> are rigidly connected or continuously formed such that sections <NUM> and <NUM> do not pivot or rotate relative to each other. In some embodiments, link sections <NUM> and <NUM> are oriented or arranged such that the link sections form an obtuse angle relative to one another. Forming an obtuse angle between link sections <NUM> and <NUM> of first link <NUM> can, in various embodiments, serve several purposes. For example, such a configuration provides the range of motion over which door <NUM> movement is constrained between the closed and open positions. Further, while providing that door movement, the obtuse angle between link sections <NUM> and <NUM> allows link section <NUM> to be positioned along a horizontally extending reinforcement <NUM> of the cab side wall <NUM> when door <NUM> is in the closed position. This prevents or reduces obstruction of the operator's view by first link <NUM>, and thereby improves visibility.

Similar to first link <NUM>, second link <NUM> of the four-bar linkage has a first pivot connection <NUM> to the frame <NUM> configured to allow link <NUM> to rotate relative to frame <NUM>. For example, pivot connection <NUM> can be on or near horizontally extending reinforcement <NUM>, or elsewhere on side wall <NUM>. As shown in the simplified illustration of <FIG>, portions of horizontally extending reinforcement <NUM> or of side wall <NUM> are removed to better show a location of pivot connection <NUM>. Second link <NUM> also has a second pivot connection <NUM>, to door <NUM>, which is again better shown in <FIG> and <FIG>. Second pivot connection <NUM> is configured to allow link <NUM> and door <NUM> to pivot relative to one another.

Like first link <NUM>, in some exemplary embodiments, second link <NUM> includes at least a first link section <NUM> and a second link section <NUM>, which are best shown in <FIG>. Link sections <NUM> and <NUM> of second link <NUM> are rigidly connected or continuously formed such that sections <NUM> and <NUM> do not pivot or rotate relative to each other. Also like first link <NUM>, in some embodiments of second link <NUM>, link sections <NUM> and <NUM> are oriented or arranged such that the link sections form an obtuse angle relative to one another in order to move door <NUM> along the desired path, and in order to allow link section <NUM> to be positioned along horizontally extending reinforcement <NUM> when door <NUM> is in the closed position. The obtuse angle formed by sections of link <NUM> need not be the same as the obtuse angle formed by sections of link <NUM>. This masking of the links <NUM> and <NUM> by the cab structure when the door is in the closed position can provide significant improvement in side visibility by an operator of the power machine. Also, providing the links <NUM> and <NUM> as shown for each four-bar linkage allows coupling of the door <NUM> to the cab without hindering or interfering with forward visibility of the operator when the door is in the fully opened position shown in <FIG> and <FIG>. In other embodiments, the linkage is positioned in alternative positions so as to remain as unobtrusive to the operator as possible. One advantageous feature of the linkage configuration shown in FIGs. is that as the door moves from a closed position to an open position, a bottom portion of the door extends out of the operator compartment space. As a result, the door moves along a path that allows for maximum headroom while the door is moving. In addition, the portion of the door that extends out of the cab also clears the lift arm no matter where the lift arm is positioned along its travel path.

In exemplary embodiments, placement of pivot connections <NUM> and <NUM> has been found to allow for improved or optimized operation of the four-bar linkage <NUM> in moving door <NUM> along its configured path, while also allowing impact on visibility to be reduced. For example, in some exemplary embodiments, it has been found that placement of lower pivot connection <NUM>, from a side view perspective, rearward of an operator seatback <NUM> and below an operator seat <NUM> provides improved results. Also, in some exemplary embodiments, it has been found that placement of upper pivot connection <NUM> vertically near the horizontal reinforcing member <NUM> is beneficial. In some alternative or more specific embodiments, placement of upper pivot connection <NUM> below a horizontally extending center line <NUM> (centered vertically) of the cab side wall <NUM> provides improved results. In some embodiments, upper pivot connection <NUM> can be in a position forward of seat back <NUM> but rearward of joystick <NUM>. For example, upper pivot connection <NUM> can be positioned at or adjacent to the Seat Index Point (SIP) for the operator seat, as defined by the seat manufacturer according to a standard such as the European Standard EN ISO <NUM>:<NUM>.

As noted above, with door <NUM> in the raised position shown in <FIG> and <FIG>, the door is positioned at least partially interior to the cab, below roof or cab top <NUM> and above a seated operator's head. To accommodate door <NUM> within cab <NUM>, in some embodiments, cab <NUM> includes an opening, at the rear of the cab, through which a portion of the door can extend when in the fully opened or raised position. For example, referring now to <FIG>, shown is a rear view of cab <NUM> illustrating an opening <NUM> in the rear frame portion <NUM> of the cab. Opening <NUM> can also be formed between rear frame portion <NUM> and cab top <NUM>. In some embodiments, to accommodate a taller door needed to provide a taller cab opening <NUM>, four-bar linkage <NUM> is configured to move door <NUM> to a position which extends the top of the door through opening <NUM> when the door is fully raised.

A cover <NUM>, shown in <FIG>, can be welded or otherwise fixedly attached to rear frame portion <NUM> to cover opening <NUM>, for example in order to enclose the operator compartment, in order to separate the door from a tailpipe of the power machine, or for other reasons. Cover <NUM> includes an upper horizontally extending channel <NUM> which covers opening <NUM>. When the top of the door <NUM> extends through opening <NUM>, the top of the door also extends into channel <NUM> of cover <NUM>. In some embodiments cover <NUM> includes an additional feature to aid in maintaining or improving visibility for the operator. As shown in <FIG>, cover <NUM> includes a flared opening <NUM> which tapers outward from a perimeter <NUM> of a rear window <NUM> of the cab. This prevents cover <NUM> from obstructing the operator's view through the rear window. Although shown as a separate piece, in some embodiments, cover <NUM> can be integrated into the cab frame.

<FIG> illustrate a cab <NUM> or portions of cab <NUM> that can be coupled to the frame of a power machine with a door <NUM> that is moveable between an open and closed position according to another illustrative embodiment. The door <NUM> is shown in the closed position in <FIG>, in a partially open position in <FIG>, and in a fully opened position in <FIG>. Like the door <NUM> discussed above, door <NUM> moves from the closed position to the opened position primarily within the cab. Unlike the door <NUM>, however, door <NUM> moves laterally rather than to a position above an operator when moving from the closed position to the open position.

Cab <NUM> defines an operator compartment <NUM> from which an operator can operate a power machine. The cab <NUM> has a frame <NUM> that includes sides <NUM> and <NUM>, top <NUM> and back <NUM>. A lower portion <NUM> is provided for space for an operator to place feet during operation of the power machine. The cab <NUM> has an opening <NUM> through which an operator can enter or exit the operator compartment <NUM> when the door <NUM> is in the open position. When the door <NUM> is in the closed position, the door will cover all or substantially all of the opening <NUM>.

In the embodiment shown in <FIG>, the door has a plurality of hangers <NUM>, <NUM>, and <NUM> that are mounted at or near edges of the door. The hangers <NUM>, <NUM>, and <NUM> are configured to engage the frame <NUM> so that the door is attached to the frame <NUM>. In addition, the hangers have features, described below, that allow the door to move relative to the frame <NUM> while at the same time remaining attached to the frame. In the embodiments shown and discussed herein, three hangers are disclosed. In other embodiments, a different number of hangers may be used to movably attached the door to the frame. As shown, hangers <NUM> and <NUM> are mounted along a top edge of the door <NUM>, while hanger <NUM> is mounted along a bottom edge of the door. Hangers <NUM><NUM> engage with a top door mounting structure <NUM> and a bottom mounting structure <NUM> to movably mount the door to the frame <NUM>. The door <NUM> includes a pair of handle assemblies <NUM> that include latching mechanisms and handles on each side of the door (i.e. the left and right sides of the door). The handle assemblies <NUM> are operable from inside and outside of the cab <NUM> to open and close the door <NUM>.

<FIG> illustrate top door mounting structure <NUM> and bottom mounting structure <NUM> in more detail. Each of the top door mounting structure <NUM> and the bottom door mounting structures have channels that are provided for engagement with the hangers. The channels collectively define a path of movement for the door <NUM> between the open and closed positions. In some embodiments, at least one of the top door mounting structure and the bottom door mounting structure has a plurality of channels. For example, the top door mounting structure <NUM> has a first channel <NUM> and a second channel <NUM>. The first channel <NUM> extends between a front position <NUM> and a back position <NUM>. The second channel <NUM> extends between a front position <NUM> and a back position <NUM>. As seen in <FIG>, the hanger <NUM> engages first channel <NUM>. As hanger <NUM> is located near the left-hand side - from the perspective of an operator sitting in the seat - and the door <NUM> is positioned on the left-hand side of the operator compartment, the first channel <NUM> extends generally in a front to back direction. Hanger <NUM> is positioned generally toward the right-hand side of the door <NUM> in the closed position and generally on the left-hand side when in the opened position. Hanger <NUM> engages the second channel <NUM>. The second channel <NUM> has a portion <NUM> that moves the hanger <NUM> leftward and then back. The second channel <NUM> also has a portion <NUM> near the front position <NUM> that moves from front to back so that the door, when moving from the closed position to the open position is first drawn back into the cab a distance before it is moved leftward.

<FIG> illustrates hangers <NUM> and <NUM> in more detail according to one illustrative embodiment. Hangers <NUM> and <NUM> are representative of hangers generally. The hangers <NUM> and <NUM> each have a main structure <NUM> and <NUM>, respectively and a plurality of rollers. The main structures each includes fastening mechanisms such as screws or bolts to attach the hanger to the door <NUM>. The main structures <NUM> and <NUM> also position rollers to engage the channels <NUM> and <NUM> and are not identical because the positioning needs of the rollers of hangers <NUM> and <NUM> are not identical. In various embodiments, the rollers can have various positioning. In the embodiment shown, hangers <NUM> and <NUM> each have a pair of generally horizontally positioned rollers <NUM> and a vertically oriented roller <NUM>. The horizontally positioned rollers <NUM> are intended to be positioned within the channels and the vertically oriented roller <NUM> is intended to be positioned on top of the top door mounting structure <NUM>. The door <NUM>, then, hangs from the vertically oriented rollers <NUM>.

<FIG> illustrate a cab <NUM> that can be coupled to the frame of a power machine with a door <NUM> that is moveable between an open and closed position according to another illustrative embodiment. Cab <NUM> is similar to the cabs <NUM> and <NUM> discussed above and has a frame <NUM> which defines, at least in part, an operator compartment <NUM>. Door <NUM> is configured to move between a closed position, as shown in <FIG> and an opened position, as shown in <FIG>. In the closed position door <NUM> covers an opening <NUM> (shown in <FIG>). <FIG> shows door <NUM> in a partially opened position. Like door <NUM>, when door <NUM> is in the opened position, the door is positioned above the operator seat <NUM> and inside the cab structure. Door <NUM>, however, discloses a different linkage structure from that of door <NUM>. <FIG> illustrates a perspective view of door <NUM> and linkage <NUM>. Linkage <NUM> includes a first link <NUM> and a second link <NUM>. First link <NUM> is mounted to the door <NUM> via a bracket <NUM> on one end <NUM> and to the cab frame at another end <NUM>. Similarly, second link <NUM> is mounted to the door <NUM> on one end <NUM> via a bracket <NUM> and to the cab frame on another end <NUM>. The door is capable of pivoting about the links <NUM> and <NUM> at each of their respective ends (and about axes <NUM> and <NUM>) to move the door between the opened and closed positions.

Also shown in <FIG> are a pair of supports <NUM> and <NUM> that are mounted to the cab <NUM> (not shown in <FIG>) and are operably coupled to the door <NUM>. The supports as shown in this embodiment are cylindrical rods (although in other embodiments, other types and shapes of supports can be used) that extend along a top of the cab. A pair of mounts <NUM> and <NUM> are slidably mounted to the supports <NUM> and <NUM>, respectively. The mounts <NUM> and <NUM> are pivotally mounted to brackets <NUM> and <NUM> and each pivotable with respect to their respective brackets along axis <NUM> as the door moves between the opened and closed positions.

<FIG> illustrates an upper rear corner of the cab <NUM> illustrating how support <NUM> is mounted to the cab, according to one illustrative embodiment. Support <NUM> extends through an aperture (not shown) in the cab <NUM> and is attached to the cab via mounting hardware <NUM>. Any suitable hardware can be used, including those that are welded or otherwise permanently fixed to the cab. Support <NUM> is also attached a front of the cab using any suitable means (not shown).

<FIG> illustrates bracket <NUM> in more detail. Mount <NUM> is pivotally mounted to the bracket <NUM> and support <NUM> extends through mount <NUM>. Mount <NUM> is shown as having a generally cylindrical shape in this embodiment, but in other embodiments can have other shapes. The bracket <NUM> is configured to be attached to the door and is shaped to properly position the mount <NUM>.

<FIG> illustrate a cab <NUM> that can be coupled to the frame of a power machine with a door <NUM> that is moveable between an open and closed position according to another illustrative embodiment. Cab <NUM> is similar to the cabs <NUM>, <NUM> and <NUM> discussed above and has a frame <NUM> which defines, at least in part, an operator compartment <NUM>. Door <NUM> is configured to move between a closed position, as shown in <FIG> and an opened position, as shown in <FIG>. In the closed position door <NUM> covers an opening <NUM> (shown in <FIG>). <FIG> shows door <NUM> in a partially opened position. Like doors <NUM> and <NUM>, when door <NUM> is in the opened position, the door is positioned above the operator seat <NUM> and inside the cab structure. Door <NUM>, however, utilizes a different linkage structure from that of doors <NUM> and <NUM>. <FIG> illustrates a perspective view of door <NUM> and linkage <NUM>. Linkage <NUM> includes a first link <NUM> and a second link <NUM>. First link <NUM> is mounted to the door <NUM> via a bracket <NUM> on one end and to the cab frame <NUM> at another end. Similarly, second link <NUM> is mounted to the door <NUM> on one end via a bracket <NUM> and to the cab frame on another end. The door is configured to pivot about the links <NUM> and <NUM> at each of their respective ends to move the door between the opened and closed positions.

In an exemplary embodiment, first link <NUM> includes a first link section <NUM>-<NUM> and a second link section <NUM>-<NUM> rigidly connected to one another, or continuously formed, such that the first and second link sections of the first link do not pivot relative to each other. The first and second link sections of the first link are oriented at an angle relative to one another such that the first link is not straight between the distal ends of the two link sections. By not utilizing a straight link, visibility for an operator of the power machine can be improved. Similar to first link <NUM>, second link <NUM> includes a first link section <NUM>-<NUM> and a second link section <NUM>-<NUM> disposed at an angle relative to one another.

Also shown in <FIG> are a pair of supports <NUM> and <NUM> that are mounted to the frame of the cab <NUM> (not shown in <FIG>) and are operably coupled to the door <NUM>. The supports as shown in this embodiment are cylindrical rods (although in other embodiments, other types and shapes of supports can be used) that extend along a top of the cab. A pair of mounts <NUM> and <NUM> are slidably mounted to the supports <NUM> and <NUM>, respectively. The mounts <NUM> and <NUM> are pivotally mounted to brackets <NUM> and <NUM> and each is pivotable with respect to their respective brackets as the door moves between the opened and closed positions.

<FIG> illustrates bracket mount <NUM> and bracket <NUM> in more detail. Mount <NUM> is pivotally mounted to the bracket <NUM>, and support <NUM> extends through mount <NUM>. Mount <NUM> can have a generally cylindrical or tubular shape which allows it to slide over a rod-shaped support <NUM>. However, in other embodiments, mounts <NUM> and <NUM>, as well as supports <NUM> and <NUM>, can have other shapes. The bracket <NUM> is configured to be attached to the door <NUM> and is shaped to properly position the mount <NUM>.

Referring back to <FIG> and <FIG>, shown are operator input device <NUM> operable from outside of the cab and handles <NUM> and <NUM>, each having operator input devices operable from inside of the cab. A first latch <NUM> is positioned on a first side of the cab door <NUM>, and a second latch <NUM> is positioned on a second side of the cab door. As will be described in greater detail with reference to <FIG>, a first complementary mechanism <NUM> is coupled to the cab frame and configured to engage the first latch <NUM> when the cab door is in the closed position (e.g., the position of <FIG>), and a second complementary mechanism <NUM> is coupled to the cab frame and configured to engage the first latch <NUM> when the cab door in in the open position (e.g., the position of <FIG>). Similarly, a third complimentary mechanism <NUM> is coupled to the cab frame and configured to engage the second latch <NUM> when the cab door is in the closed position, and a fourth complementary mechanism <NUM> is coupled to the cab frame and configured to engage the second latch <NUM> when the cab door in in the open position.

As shown for example in <FIG>, cab door <NUM> also includes a first handle <NUM> and a second handle <NUM> on an interior of the door, positioned respectively near the first latch <NUM> and the second latch <NUM>. Each of the handles <NUM> and <NUM> has an operator input <NUM> (shown for handle <NUM> in <FIG> and <FIG>) which is configured to release two latch release mechanisms. For instance, <FIG> illustrates first complimentary mechanism <NUM> configured to engage the first latch <NUM> when the cab door is in the closed position. A first latch release mechanism <NUM> is positioned adjacent the first complementary mechanism <NUM> and is configured to release the first latch <NUM> from engagement with the first complementary mechanism. First latch release mechanism <NUM> can be actuated through a push-pull cable <NUM>. <FIG> and <FIG> illustrate first latch <NUM>, first complimentary mechanism <NUM> and first latch release mechanism <NUM> in relation to handle <NUM> and operator input <NUM>. Actuation of operator input <NUM> causes first latch release mechanism <NUM> to release the first latch <NUM> from engagement with first complimentary mechanism <NUM>, allowing the door to be moved. In response, push-pull cable <NUM> also actuates a second latch release mechanism <NUM> (shown in <FIG>).

As shown in <FIG>, a second latch release mechanism <NUM> is positioned adjacent the second complementary mechanism <NUM> which engages the first latch <NUM> when the cab door in in the open position. In an exemplary embodiment, the second complementary mechanism <NUM> and second latch release mechanism <NUM> are positioned toward a rear of the cab. The second latch release mechanism <NUM> is configured to release the first latch <NUM> from engagement with the second complementary feature <NUM>. As can be seen in <FIG>, second latch release mechanism <NUM> is coupled to and can be actuated by push-pull cable <NUM>. As actuation of either of first latch release mechanism <NUM> or second latch release mechanism <NUM> by operator input <NUM> causes actuation of the other latch release mechanism due to their coupling by push-pull cable <NUM>, actuation of a single operator input <NUM> causes actuation of both the first latch release mechanism <NUM> and the second latch release mechanism <NUM>.

Although not separately illustrated or numbered, a third latch release mechanism (similar to latch release mechanism <NUM>) is positioned adjacent the third complementary mechanism <NUM> and configured to release the second latch <NUM> from engagement with the third complementary feature, and a fourth latch release mechanism (similar to latch release mechanism <NUM>) is positioned adjacent the fourth complementary mechanism <NUM> and configured to release the second latch <NUM> from engagement with the fourth complementary mechanism. Being coupled together by a second push-pull cable (similar to push-pull cable <NUM>), the actuation of either of the third and fourth latch release mechanisms by a second operator input (similar to operator input <NUM>) on handle <NUM> causes actuation of the other latch release mechanism. Thus, actuation of a single operator input on the handle <NUM> (or elsewhere in other embodiments) causes actuation of both the third latch release mechanism and the fourth latch release mechanism. In exemplary embodiments, single operator input device <NUM> (shown in <FIG>) that is operable from outside of the cab is configured to actuate all of the first latch release mechanism, the second latch release mechanism, the third latch release mechanism, and the fourth latch release mechanism to release the first and second latches <NUM> and <NUM> from the corresponding complimentary mechanisms <NUM>, <NUM>, <NUM> and <NUM>. As shown in the interior view of a front portion of cab frame <NUM> provided in <FIG>, single operator input device <NUM> is coupled to the latch release mechanisms through a push-pull cable arrangement originating from push pull cables <NUM> and <NUM> connected to the single operator input device <NUM>.

Referring now to <FIG>, shown is a portion of cab frame <NUM> defining an opening <NUM> and cab door <NUM> with a seal configuration. A shown, a first seal <NUM> is positioned on a first portion <NUM> of the cab door and configured to engage a first portion <NUM> of the cab frame when the door is in the closed position. In one exemplary embodiment, the first portion <NUM> of the cab door is a bottom portion of the cab door and the first portion <NUM> of the cab frame defines a bottom portion of the opening <NUM>. The first portion <NUM> of the cab frame defining the bottom portion can be a lip (as shown in <FIG>) that the door seal engages when the door is in the closed position. A second portion <NUM> of the cab door is a top portion of the cab door, and a second portion <NUM> of the cab frame defines a top portion of the opening (<NUM>). The seal configuration further includes a second seal <NUM> on the second portion <NUM> of the cab frame configured to engage the second portion <NUM> of the cab door when the door is in the closed position.

When closing the cab door <NUM> in opening <NUM>, as the door moves from the open position (e.g., as shown in <FIG>) to the closed position (e.g., as shown in <FIG>), the first portion <NUM> of the cab door moves the first seal <NUM> into engagement with the first portion <NUM> of the cab frame from outside of the cab. This progression of door positions can be seen <FIG>, <FIG> and <FIG>. Also, as the door moves from the open position to the closed position, the second portion <NUM> of the cab door moves into engagement with the second seal <NUM> from inside of the cab.

Claim 1:
A cab (<NUM>) for a power machine, the cab comprising:
a cab frame (<NUM>) forming an operator compartment (<NUM>) and having a first side wall (<NUM>), a second sidewall (<NUM>), a front (<NUM>), a rear (<NUM>), a top (<NUM>) and a bottom (<NUM>);
a cab door (<NUM>) configured to cover an opening (<NUM>) in the front of the cab frame when in a closed position; and
a first four-bar linkage (<NUM>) coupled to the cab frame and the cab door, wherein the first four-bar linkage includes first and second links (<NUM>, <NUM>), each of which is pivotally mounted to the cab frame (<NUM>) and the cab door (<NUM>), and wherein the first four-bar linkage (<NUM>) is configured to define a path of movement for and support the cab door as the cab door moves between the closed position and an open position, wherein in the open position the cab door is positioned overhead of an operator seat (<NUM>) beneath the cab top;
characterized by:
the first four-bar linkage (<NUM>) being positioned within the operator compartment adjacent the first side wall (<NUM>).