Patent Description:
The invention relates to a telescoping boom materials handler, i.e., a telehandler and, more particularly, to a telehandler incorporating a cantilever boom mounting providing an extended reach and added functionality and maneuverability.

Existing high-capacity and ultra-high-capacity telehandlers utilize a fixed frame design with four steerable wheels. The use of large diameter, wide tires limits the space available for the wheels to turn (unless the machine is made excessively wide), resulting in limited steering angles. As a consequence, typical machines of this type have large turning radii, making the machines less maneuverable.

Existing machines with traditional four-wheel steering lack the ability to correct a position of the load in use. If an operator approaches the landing place for the load at the wrong angle, the operator is required to back up the machine to correct its location and orientation and re-approach the landing.

Known articulated telehandlers typically have a short boom mounted in front of the operator cab. The boom pivot pin is positioned in front of the central articulated joint. These machines thus have better steering capabilities but limited reach and functionality. Moreover, articulated telehandlers (and articulated wheel loaders) have variable stability ratings when the frame is in a straight position versus when the frame is in an articulated (steered) position. Existing articulated machines thus typically require a shorter boom to prevent the machine from becoming unstable when carrying a load and rely on operator judgment to establish if the machine can be steered when loaded with the boom extended and/or elevated.

A known telehandler is described in document <CIT>. This telehandler comprises a frame supporting an operator cab; a pair of front wheels and a pair of rear wheels coupled with the frame, wherein the frame comprises a forward frame supporting the operator cab and an aft frame coupled with the forward frame at a coupling point, wherein the pair of front wheels is coupled with the forward frame, wherein the pair of rear wheels is coupled with the aft frame; a cantilever support secured at a fixing point to the forward frame, the cantilever support extending from the fixing point aft beyond the coupling point to a boom support adjacent a distal end of the cantilever support; and a boom pivotably secured to the boom support at a boom pivot, wherein the fixing point is forward of the coupling point, and wherein the boom support is vertically spaced from the aft frame, wherein the coupling point comprises a frame pivot, and wherein the forward frame is pivotable relative to the aft frame via the frame pivot. In this arrangement the boom support extends aft to a position forward the axle of the rear wheels.

The telehandlers described below incorporate a cantilever boom mounting that provides for a fixed frame or articulated frame telehandler with an extended reach boom. The cantilever boom mounting in the fixed frame machine additionally provides for improved service access (for installation, maintenance and service), when compared to typical telehandlers with in-line powertrain layouts. An integrated control and stability management system in the articulated frame machine may provide for improved stability characteristics.

According to the invention, a telehandler includes a frame supporting an operator cab, a pair of front wheels and a pair of rear wheels coupled with the frame, and a cantilever support secured at a fixing point to the frame. The cantilever support extends from the fixing point aft to a boom support adjacent a distal end and aft of an axle of the rear wheels. A boom is pivotably secured to the boom support at a boom pivot.

The frame includes a forward frame supporting the operator cab and an aft frame coupled with the forward frame at a coupling point. In this context, the pair of front wheels is coupled with the forward frame, and the pair of rear wheels is coupled with the aft frame. The cantilever support extends from the fixing point aft beyond the coupling point to the boom support. The coupling point includes a frame pivot, where the forward frame is pivotable relative to the aft frame via the frame pivot. The frame pivot is pivotable on a vertical axis such that the telehandler may be configured for articulated steering.

The boom may include an angled end adjacent the boom pivot. The boom may include a telescoping section or sections. The telehandler may further include an extendable actuator connected between the cantilever support and the boom. Still further, the telehandler may include a controller that receives data input with respect to a position of the forward frame relative to the aft frame, a position of the extendable actuator, an extension amount of the telescoping boom, and a load on the telescoping boom, where the controller may be programmed to control a position of the load based on the data input and manage a relationship between steering angle and boom position/load. The controller may be programmed to restrict at least one of boom displacement and a steering angle based on the load on the boom and a position of the boom.

The boom pivot is arranged aft of an axle of the rear wheels. The cantilever support may be oriented at an angle from a low position at the fixing point to a high position at the distal end. The boom support is arranged vertically spaced from the aft frame.

In an example not part of the claimed invention, an articulating telehandler includes a forward frame supporting an operator cab, front wheels coupled with the forward frame, an aft frame pivotably coupled with the forward frame at a frame pivot having a vertical axis, and rear wheels coupled with the aft frame. A cantilever support is secured at a fixing point to the forward frame and extends from the fixing point aft beyond the frame pivot to a boom support adjacent a distal end. A telescoping boom is pivotably secured at a boom pivot to the boom support.

In yet another an example not part of the claimed invention, an articulating telehandler includes an articulated frame including a front frame segment and a rear frame segment separated by a frame pivot. A cantilever support extends from a fixing point on the front frame segment aft beyond the frame pivot to a boom support adjacent a distal end. A boom is pivotably secured at a boom pivot to the boom support. In this context, the boom may include at least one telescopic segment, and the telehandler further includes a drive system, a controller communicating with the drive system, a load sensor that measures a load on the boom, a boom position sensor that measures at least one of a boom height and a boom length, and a steering sensor that measures an angle between the front frame segment and the rear frame segment. The controller may receive input from the load sensor, the boom position sensor and the steering sensor. The controller may be programmed to restrict operation of the drive system based on the load on the boom, at least one of the boom height and the boom length, and the angle between the front frame segment and the rear frame segment.

These and other aspects and advantages will be described in detail with reference to the accompanying drawings, in which:.

With reference to <FIG> and <FIG>, a telehandler <NUM> includes a forward frame <NUM> supporting an operator cab <NUM>. The forward frame <NUM> is provided with a set of front wheels <NUM> for supporting the forward frame <NUM>. An aft frame <NUM> is coupled with the forward frame <NUM> at a coupling point <NUM>. The aft frame <NUM> is provided with a set of rear wheels <NUM> for supporting the aft frame <NUM>. References to forward and aft directions as well as front and rear wheels are relative to a driving direction of the telehandler <NUM>. A drive system including an engine and transmission drives one or both sets of wheels <NUM>, <NUM>. The drive system also includes control implements for positioning the boom/load and for steering. In the illustrated embodiment, driving components including the engine and transmission drive and the like are housed within an engine casing <NUM> that forms part of the aft frame <NUM>.

The coupling point <NUM> is a frame pivot such that the forward frame <NUM> is pivotable relative to the aft frame <NUM> via the frame pivot. Specifically, the coupling point or frame pivot <NUM> is pivotable on a vertical axis relative to a horizontal ground such that the telehandler <NUM> is configured for articulated steering. The frame pivot <NUM> may comprise a dual axis pivot including a horizontal axis pivot, so the rear frame can rotate in relation to the front frame to accommodate uneven terrain, and a vertical axis pivot for steering. In other embodiments, the center pivot has only a vertical axis pivot for steering, and the rear axle is mounted to the aft frame <NUM> via an axial pivot (oscillating axle design). As with conventional articulated steering vehicles, an actuator (not shown) pivots the forward and aft frames <NUM>, <NUM> relative to one another to steer the telehandler <NUM>. For example, an operator may steer the vehicle by manipulating a steering wheel or steering handle/joystick located in the cab <NUM>. In some arrangements, the operator cab is equipped with both a steering wheel and a steering handle to command speed and direction of travel with an operator selector switch. Providing both gives the operator an option. Often, a steering wheel is preferred for longer, transport drives, whereas handle or joystick operation may be used during loading operations. Various drive arrangements may be employed for propelling the vehicle with the drive system in a two- or four-wheel drive configuration.

A cantilever support <NUM> is secured at a fixing point to the forward frame <NUM>. The antilever support <NUM> is secured to the forward frame and may be integral with the forward frame <NUM>. The cantilever support <NUM> extends from the fixing point aft beyond the coupling point <NUM> to a boom support <NUM> adjacent a distal end. As shown, in some embodiments, the cantilever support <NUM> is oriented at an angle from a low position at the fixing point to a high position at the distal end. Additionally, in some embodiments, the boom support <NUM> is vertically spaced from the aft frame <NUM>.

A boom <NUM> is pivotably secured to the boom support <NUM> at a boom pivot <NUM>. The boom pivot <NUM> is aft of the coupling point/frame pivot <NUM> and in a preferred construction is aft of an axle <NUM> of the rear wheels <NUM>. In this context, the distal end of the cantilever support <NUM> is positioned aft of the rear wheel axle <NUM> as shown. The forward frame <NUM> forms part of a forward section of the machine, which includes the forward frame <NUM>, operator cab <NUM>, front axle <NUM> and cantilever support <NUM>. The aft frame <NUM> forms part of a rear section of the machine, which includes the aft frame <NUM>, the engine (not shown), engine casing <NUM>, engine hood, etc..

The boom <NUM> is preferably a telescoping boom that is extendable and retractable by a suitable actuator. A lifting actuator <NUM> is connected between the cantilever support <NUM> and/or the forward frame <NUM> and the boom <NUM>. Extension of the lifting actuator <NUM> raises the boom <NUM> by pivoting the boom <NUM> on the boom pivot <NUM>. A work implement <NUM> such as the fork carriage shown in the drawings is attached at a distal end of the boom <NUM>. The manner of connecting the work implement <NUM> and controlling the work implement <NUM> during use are known and will not be further described.

In some embodiments, as shown in the drawings, the boom <NUM> includes an angled end <NUM> adjacent the boom pivot <NUM>. As shown in <FIG>, the angled end <NUM> serves to provide the boom <NUM> with an effective length that is beyond the boom pivot point <NUM>. The angled end <NUM> enables the boom <NUM> to be raised without impacting the components mounted under the boom <NUM> or cantilever support <NUM> (see <FIG>).

The stability of the telehandler <NUM> may be managed by an electronic Integrated Control System (ICS) or Master Machine Controller (MMC). An exemplary ICS <NUM> is shown schematically in <FIG>. The ICS <NUM> communicates with a load management indicator system (LMIS) module <NUM>. Together, the ICS <NUM> and LMIS module <NUM> receive input from various sensors and signals from operator controls <NUM> that include steering wheel (or steering joystick) position information. The ICS <NUM> drives a display <NUM> that displays information to the operator, and the ICS <NUM> provides commands to vehicle controls <NUM> that include electrical controllers of hydraulic valves and the like.

The LMIS module <NUM> receives input from sensors that measure various structural characteristics and operating parameters of the machine related to loading conditions. For example, sensors may include a boom angle (indicating height) sensor <NUM>, a boom length sensor <NUM>, a load <NUM> on the boom, which can be established by measuring pressure in the hydraulic cylinders or measured directly. Knowing the load <NUM> and the position of the load via sensors <NUM> and <NUM>, the LMIS module <NUM> can determine a load moment of the machine in relation to the boom pivot point <NUM>. The LMIS module <NUM> and ICS <NUM> can be separate hardware devices or can be functional blocks of software incorporated into one hardware controller. Reference to a "controller" in the present specification is intended to encompass all control hardware and functionality including, without limitation, the ICS (or MMC) <NUM> and the LMIS module <NUM>.

For an articulated frame telehandler, the stabilizing moment of the machine depends on the position of the frame pivot (steering angle). A steering angle sensor <NUM> provides this information. Also, the position/manipulation of the operator controls <NUM> and the like is communicated to ICS <NUM>, which processes the data from the various sensors <NUM>-<NUM> to control a position of the load and/or steering (frame pivot positions) by communicating with the vehicle controls <NUM>. For example, with reference to <FIG>, with the boom <NUM> in a raised and extended position, based on a relative angle of the front frame <NUM> to the aft frame <NUM> (steering angle), certain positions of the load <NUM> supported on the work implement <NUM> may cause the telehandler to become unstable, e.g., approaching a tipping condition. In the configuration shown in <FIG>, if the operator attempts to move the load by steering function to the left (down in the figure), the position of the load <NUM> may cause the telehandler to become unstable. The controller prevents the operator from steering to move the load <NUM> to a position that could cause instability. In the orientation shown in <FIG>, further steering to the left can be prohibited. The operator can resolve this situation by retracting the boom, lowering the boom and moving the machine closer to the building.

Different restrictions/permissions can be effected by the ICS <NUM> if the operator is travelling with the boom fully retracted and lowered and steers the machine to the high steering angle. In this case, the ICS <NUM> may prohibit (cut out) vehicle controls <NUM> allowing boom lift or extension based on information from the LMIS <NUM>.

<FIG> shows that the machine can pick up the maximum rated load when the boom is fully retracted and the operating implement (such as the fork carriage shown) is close to the ground. The position shown in <FIG> is the position of load causing minimum instability moment. Maximum (rated) load is selected to allow full steering functionality (i.e., the ability to achieve any steering angle up to and including a maximum steering angle allowed by the articulated frame steering mechanism). Typically, the operator keeps the machine in this position for travel. When the operator moves the load from this transport position, several restrictions may occur - for example, if the machine is steered as shown schematically in <FIG>, boom movement up/down or extension/retraction can be prohibited at a given, actual load measured by LMIS <NUM>. If the boom is elevated and extended with a particular load, steering beyond an angle determined by ICS <NUM> can be restricted (prohibited) as shown in <FIG>. Situations described above and illustrated in <FIG> and <FIG> can happen only at low speeds, thereby providing the operator time to adjust to given restrictions and find a way to resolve them.

The system can provide the operator with a warning or other graphic or the like to indicate why the vehicle is not responding to operator control requests. The graphics displayed on display <NUM> installed in the cab <NUM> can be similar to information shown in <FIG> or can be designed in alternative ways to indicate which functions are allowed and which are prohibited.

<FIG> shows an example not part of the claimed invention for a fixed frame telehandler <NUM> with a cantilevered boom mount extending from the frame with a boom pivot point beyond rear axle and above the engine compartment. The fixed frame embodiment incorporates similar design features as the articulating frame embodiment(s) described above. The machine build along these lines would have better engine positioning than existing fixed frame designs where the engine is nested between frame sides and below the boom. The cantilevered boom support starts in front of the rear axle and extends to an area behind the rear axle and above the engine compartment. As shown, the engine is mounted below the cantilevered section angled end of the boom.

The described embodiments utilize a cantilever boom mounting to provide a stable telehandler with an extended reach. The cantilever boom mounting additionally provides for a telehandler with an articulated frame to facilitate vehicle and load positioning and to reduce a turning radius of the telehandler.

Claim 1:
A telehandler comprising:
a frame (<NUM>, <NUM>) supporting an operator cab (<NUM>);
a pair of front wheels (<NUM>) and a pair of rear wheels (<NUM>) coupled with the frame, wherein the frame comprises a forward frame (<NUM>) supporting the operator cab (<NUM>) and an aft frame (<NUM>) coupled with the forward frame (<NUM>) at a coupling point (<NUM>), wherein the pair of front wheels (<NUM>) is coupled with the forward frame, wherein the pair of rear wheels (<NUM>) is coupled with the aft frame;
a cantilever support (<NUM>) secured at a fixing point to the forward frame, the cantilever support (<NUM>) extending from the fixing point aft beyond the coupling point (<NUM>) to a boom support (<NUM>) adjacent a distal end of the cantilever support (<NUM>) and the boom support (<NUM>) is extending aft of an axle (<NUM>) of the rear wheels; and
a boom (<NUM>) pivotably secured to the boom support (<NUM>) at a boom pivot (<NUM>), the boom pivot (<NUM>) being aft of the axle (<NUM>) of the rear wheels,
wherein the fixing point is forward of the coupling point (<NUM>), and wherein the boom support (<NUM>) is vertically spaced from the aft frame (<NUM>),
wherein the coupling point (<NUM>) comprises a frame pivot (<NUM>), and wherein the forward frame (<NUM>) is pivotable relative to the aft frame (<NUM>) via the frame pivot (<NUM>).