Patent Description:
Portable radial stackers have been used for many years to stack bulk materials such as aggregate for road construction, grain, coal, and mulch. Radial stackers, which swing around in a radius to stack material in an arc, permit substantially more material to be stacked than is possible using a conventional stationary stacker that permits only a conical stack. Telescoping radial stackers permit even more material to be stacked as the stacker is extended or retracted during conveying operations.

Radial stackers typically include a wheeled axle disposed between a hopper and the top of the stacker from which the material is discharged. These wheels permit the stacker to be swung in an arc, with the hopper including a pivot plate on which the stacker pivots.

An additional advantage of having a wheeled radial stacker is that the stacker may be folded over itself and be ready for road transport in relatively little time, as the wheels that are used for radial travel can be displaced into a position aligned with the stacker to support the stacker for travel.

In recent years, tracked drives have been used in quarries, agricultural and mining operations to enable equipment to be moved over harsh terrain for ideal positioning for stacking operations. While tracked vehicles have proven to be of great benefit for such purposes, the use of tracks instead of wheels makes it more difficult to shift a stacker radially to facilitate the stacking of material in an arc instead of a cone. Also, because tracked vehicles are not typically permitted to be driven on road surfaces, they are normally loaded onto flatbed trucks for transit from one work site to another. These two drawbacks with the use of tracks has to a certain extent limited the use of tracked vehicles.

While portable radial stackers are extremely versatile in that they can operated on a wide variety of terrain and in a variety of conditions, certain materials to be stacked create unique problems. Given the requirement that stacking conveyors need to be able to stack in large, high piles, it is necessary that the angle of inclination of the conveyor be relatively steep, often as steep as <NUM> degrees or more. This is also true when the conveyors are being used to load ships that might be riding high in the water.

While the inclination issue may not be a problem with some bulk materials that exhibit a high degree of friction on the conveyor belt, other materials such as river rock and salt do not exhibit such friction. Special conveyor belts bearing ribs or other friction-increasing features may be used to convey such low-friction materials but this may require removal and replacement of the belt, which is not an easy task to complete on site. It is also necessary that conveyors be able to operate in a wide variety of weather conditions, such as rain, snow and ice. Bulk materials that can be conveyed at a steep angle when dry might be more difficult to convey in the presence of moisture or winter conditions. While the angle of inclination is adjustable in most portable radial conveyors, reducing the angle of inclination will often substantially reduce the size or height of the piles into which the stacker can deposit bulk material.

<CIT> is concerned with a mobile radial stacker according to the preamble of claim <NUM>. <CIT> relates to a conveyor system. <CIT> discloses a stacker drive module. <CIT> is concerned with a tracked radial stacker with wheels according to the preamble of claim <NUM> and with a process according to the preamble of claim <NUM>.

Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings and the appended claims. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense.

Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments. However, the order of description should not be construed to imply that these operations are order-dependent.

The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments.

The terms "coupled" and "connected," along with their derivatives, may be used. Rather, in particular embodiments, "connected" may be used to indicate that two or more elements are in direct physical or electrical contact with each other. "Coupled" may mean that two or more elements are in direct physical or electrical contact. However, "coupled" may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

The description may use the terms "embodiment" or "embodiments," which may each refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," and the like, as used with respect to embodiments, are synonymous, and are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.).

With respect to the use of any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application.

Embodiments disclosed herein include a stacker for stockpiling bulk material. The stacker may include a linear conveyor having a rear portion including a hopper, and front portion, the conveyor being designed to carry bulk material along an elevating path from a low position adjacent the rear portion to a higher position adjacent the front portion. At least one leg may be mounted to the frame below the hopper, the at least one leg may include a hydraulic jack for increasing and decreasing the effective length of the leg, thereby raising and lowering the rear portion of the conveyor to increase and decrease a degree of elevation of the path. The hopper may be pivotally mounted to the conveyor, with hydraulic cylinders mounted thereto in order to raise and lower an end of the hopper to alter a degree of inclination of the hopper. Means may also be provided for automatically maintaining the hopper in a horizontal disposition regardless of the degree of elevation of the conveyor.

Embodiments disclosed herein also provide a portable radial stacker for stockpiling bulk material. The stacker may include a linear conveyor having a rear portion and a front portion mounted to a frame and being designed to carry bulk material from a low position adjacent the rear portion to a higher position adjacent the front portion. A hopper may be mounted to the rear portion of the conveyor, with a contact mounted to the frame at the rear portion of the conveyor being designed to contact the ground to facilitate pivoting of the conveyor, the contact being adjustable in length. A pair of mid-wheels may also be mounted to the frame that can be positioned in a radial direction to facilitate radial shifting of the stacker, At least one hydraulic jack may be mounted to the contact for selectively elevating the rear portion of the conveyor to increase the elevation of the low position to reduce an angle of elevation of the conveyor.

The contact may be positioned directly below the hopper, and may be pivotable to permit it to extend substantially vertically regardless of the angle of the conveyor. The contact may include at least one leg mounted to a pivot pad for contacting the ground below the rear portion of the conveyor.

The leg may include a rear wheel mounted thereto, and the rear wheel may be pivotally mounted to move between longitudinally- and laterally-extending positions. The rear wheel may be moveable between a raised position and a lowered position, and in its lowered position, the rear wheel may lift the tracks off the ground to permit movement of the conveyor on the rear wheel. The mid-wheels and the rear wheel can be positioned to extend longitudinally.

The hopper may also be pivotally mounted to the stacker so that it can be maintained in a substantially horizontal position regardless of the angle of elevation of the conveyor.

The stacker may also have: a continuous track system including a pair of driven, parallel tracks designed to contact the ground to convey the stacker from one position to another, and to be lifted off the ground when desired, wherein the mid-wheels are displaceable between a raised position in which they do not contact the ground and a lowered position in which they engage the ground. It may also include a hydraulic wheel displacement system for powering the mid-wheels from a raised position in which the tracks are on the ground to the lowered position in which the tracks are lifted off the ground to facilitate radial movement of the stacker with the tracks raised off of the ground. The hydraulic wheel displacement system may operate each of the mid-wheels independently so the mid-wheels can be at different even lower positions to facilitate the stacker being operable on uneven terrain.

In this embodiment, the hopper may be pivotally mounted to the stacker so that it can be maintained in a substantially horizontal position regardless of the angle of elevation of the conveyor.

Another embodiment of the disclosure may provide a tracked, portable radial stacker for stockpiling bulk material, having the following components: a linear conveyor having a frame, a rear portion and a front portion and being designed to carry bulk material from a low position adjacent the rear portion to a higher position adjacent the front portion; a bogie mounted to the frame; at least one leg mounted below the rear portion of the conveyor and being designed to selectively contact the ground, the leg being adjustable in length to facilitate pivoting of the conveyor; a continuous track system mounted to the bogie, including a pair of driven, parallel tracks designed to contact the ground to convey the stacker from one position to another, and to be lifted off the ground when desired; a pair of mid-wheels mounted to the bogie and a pair of mid-hydraulic cylinders for powering the mid-wheels between raised positions in which the mid-wheels do not contact the ground and lowered positions in which the mid-wheels contact the ground, the mid-hydraulic cylinders facilitating the lifting of the tracks off the ground as the mid-wheels are powered to their lowered positions to permit movement of the conveyor on the mid-wheels; and at least one hydraulic jack mounted to the at least one leg for selectively elevating the rear portion of the stacker to increase the elevation of the low position to reduce an angle of elevation of the stacker.

In this embodiment, the leg may include a rear wheel at one end and wherein the mid-wheels and the rear wheel can be swiveled so the mid-wheels and the rear wheel can all extend either longitudinally or laterally. This embodiment may also include a hopper disposed adjacent the rear portion of the conveyor, the hopper being pivotally mounted to the stacker so that it can be maintained in a substantially horizontal position regardless of an angle of elevation of the conveyor.

Embodiments disclosed herein may also be described as a process for changing the decree of incline of a portable radial stacker, including the following steps, not necessarily in the order recited: selecting a linear conveyor having a frame, a rear portion and a front portion and being designed to carry bulk material from a low position adjacent the rear portion to a higher position adjacent the front portion; mounting at least one leg to the frame, adjacent the rear portion of the conveyor, the leg being designed to support the rear portion of the conveyor and to contact the ground to facilitate the pivoting of the conveyor, the leg further including a hydraulic cylinder for selectively extending and reducing the effective length of the leg; mounting a continuous track system to the frame, the track system including a pair of driven, parallel tracks designed to contact the ground to convey the stacker from one position to another, and to be lifted off the ground when desired; mounting a pair of mid-wheels to the frame forward of the contact; mounted a pair of mid-hydraulic cylinders to the mid-wheels for powering the mid-wheels between raised positions in which the mid-wheels do not contact the ground and lowered positions in which the mid-wheels contact the ground, the mid-hydraulic cylinders facilitating the lifting of the tracks off the ground as the mid-wheels are powered to their lowered positions to permit movement of the conveyor on the mid-wheels; and mounting at least one hydraulic jack to the at least one leg for selectively elevating the rear portion of the conveyor to increase the elevation of the low position to reduce an angle of elevation of the stacker.

The step of mounting the at least one leg to the frame may include selecting a leg that includes a pivotable rear wheel adjacent one end of the leg. It may also include the step of mounting a hopper adjacent the rear portion of the frame, and the step of mounting at least one leg to the frame may comprise mounting the leg below the hopper. This step of mounting a hopper adjacent the rear portion of the frame may include pivotally mounting the hopper with a hydraulic system for raising and lowering a rear end of the hopper to change a degree of elevation of the hopper.

Another way to define the disclosed embodiments is as a portable radial stacker for stockpiling bulk material, including a linear conveyor having a rear portion including a hopper, and front portion, the conveyor being designed to carry bulk material along an elevating path from a low position adjacent the rear portion to a higher position adjacent the front portion, wherein the hopper is pivotally mounted to the conveyor with hydraulic cylinders mounted there between to raise and lower an end of the hopper to modify a degree of elevation of the hopper. This embodiment may include means for maintaining the hopper in a horizontal disposition regardless of the degree of elevation of the elevating path.

A tracked stacker is identified generally at <NUM> in the figures. <FIG> show stacker <NUM> to be ready to be radially shifted (sometimes referred to herein as "lateral movement" or "laterally"). Stacker <NUM> includes a conveyor, indicated generally at <NUM>, a track system, indicated generally at <NUM>, and a wheel system, indicated generally in <FIG>. A system for elevating and lowering stacker <NUM>, indicated generally at <NUM>, is shown in <FIG>, taken along line <NUM>-<NUM> of <FIG>.

More specifically, conveyor <NUM> may include a hopper <NUM>, a main conveyor portion <NUM> and a discharge end <NUM>. The depicted conveyor includes a joint <NUM>, which may permit the conveyor to double back over itself as shown in <FIG> to facilitate road travel. Hydraulic cylinders <NUM> may be provided at either side of conveyor <NUM> to facilitate the pivot action and control the position of discharge end <NUM> relative to main conveyor portion <NUM>. Rollers <NUM> are typically included to guide a belt, which has been deleted from the figures to better show the features of the conveyor. A pivot point <NUM> may be provided under hopper <NUM> to facilitate the radial shifting of the conveyor. Pivot point <NUM> is typically designed to be readily replaced with a fifth wheel king pin mount <NUM> (see <FIG>) to be mounted to a tractor for transport to another site, as will be explained more fully as this discussion continues.

Conveyor <NUM> is designed to be disposed in various angular positions for various levels of stacking and for transit. This capability may be facilitated by a pair of support frames disposed at each end of main portion <NUM> of the conveyor. These support frames also help raise and lower track system <NUM>, as will be explained more fully below. Rear support frames <NUM> extend from track system <NUM> to the underside of rearward aspect of main portion <NUM> of the conveyor. Normally, rear support frames <NUM> will be of telescoping construction. One of the rear support frames <NUM> may be disposed on each lateral side of conveyor <NUM> to provide sufficient support and balance to the conveyor. A pair of rear intermediate support frames <NUM> may also be included, and in the depicted embodiment extend from a track system mounting frame <NUM> to the underside rear aspect of main portion <NUM> of the conveyor. Rear intermediate support frames <NUM> may also be telescoping, but typically are not.

Rear support frames <NUM> may be provided with hydraulic rams <NUM> to provide power to reposition the rear support frames and to raise and lower the rear end of conveyor <NUM> to permit stacker <NUM> to be repositioned to lower the tracks to the ground and to facilitate mounting of king pin <NUM> to a fifth wheel of a tractor. Rear support frames <NUM> may also be provided with pegs and complementing holes (not shown) to fix the support frame in position during operations when the hydraulic rams are not changing the position of the rear support frames.

A pair of front support frames <NUM> may also be provided to extend from track system <NUM> to the underside of a forward aspect of main portion <NUM> of the conveyor. Front support frames <NUM> are normally telescoping in configuration. One of the front support frames <NUM> may be disposed on each lateral side of conveyor <NUM> to provide sufficient support and balance to the conveyor. Front support frames <NUM> are normally provided with hydraulic rams <NUM> to provide power to reposition the support frames, and may be provided with pegs and complementing holes (not shown) to fix the support frame in position during operations when the hydraulic rams are not changing the position of the front support frame.

Track system <NUM> is conventional in that it includes a pair of continuous tracks <NUM> mounted to track system mounting frame <NUM>. Tracks <NUM> are driven by an engine through either a mechanical transmission or hydraulic drive. The drive typically provides the capability of reversibility to maximize the maneuverability of the unit.

A bogie <NUM> for wheel system <NUM> is shown best in <FIG>. Wheel system <NUM> typically includes a pair of wheels <NUM>, although in <FIG>, in a slightly different embodiment, a pair of coaxial wheels <NUM> are depicted. However, coaxial wheels <NUM> will be sometimes described herein as though they are a single wheel. Wheels <NUM> and <NUM> will sometimes be referred to herein as mid-wheels since they are generally at a mid-point of the conveyor. Because the embodiment of <FIG> is slightly different in the arrangement of the wheels but the rest of the stacker is the same, the numbers for this slightly different embodiment have are not different from the numbers in embodiment <NUM>-<NUM>.

When in their lowered, lateral position (ready for either radial or <NUM> degree displacement of stacker <NUM>) shown in <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG>, wheels <NUM> or <NUM> support tracks <NUM> in an elevated position. With the wheels in the radial, lateral position, stacker <NUM> can be driven in a radial direction to provide a second conical stack of bulk material, or to provide additional stacks in an arc. With the wheels in a <NUM> degree lateral position, and pivot point <NUM> or king pin <NUM> mounted to a tracked bogie, such as that shown in <FIG> and <FIG>, the stacks can take the form on a long pile, or the stacker can be used to fill one or more barges, trucks or rail cars. The additional tracked bogie <NUM> may be used to reposition a stacker for longitudinal displacement by shifting the additional bogie and wheels <NUM> by <NUM> degrees if for some reason that is preferable to operating the stacker through longitudinal movement of the tracks <NUM> of bogie <NUM>.

To provide power drive to wheels <NUM> or <NUM>, a chain drive <NUM> may be included as shown schematically in <FIG> or a hydraulic planetary drive motor <NUM> as shown in <FIG>.

After stacker <NUM> is properly positioned, wheels <NUM> can be translated to a raised position in which they no longer contact the ground, one of such positions being shown in <FIG> (in phantom) and <NUM>. In this raised position, wheels <NUM> also may rotate approximately <NUM> degrees, to the depicted position such that the axes of the wheels extend laterally of stacker <NUM>. This rotation may be effected using hydraulics or some other power means or may be performed manually with pegs and complementing holes (not show).

The raised position of wheels <NUM> is shown in <FIG>, although they may alternatively be raised from one of their lateral (radial or <NUM> degree) positions.

When wheels <NUM> are in their raised positions, tracks <NUM> contact the ground to ensure maximum maneuverability around the job site. With wheels <NUM> well up and out of the way as depicted in <FIG>, there is little risk of the wheels and their tires being damaged despite the rough environment in which the stacker is operating. Wheels <NUM> are each supported by a leg <NUM>, and are outfitted with a web <NUM>. A hydraulic cylinder <NUM> extends between each of the two webs <NUM> of wheels <NUM> and bogie <NUM>. The pair of hydraulic cylinders <NUM> maintain the two wheels in their lowered and raised positions, although pegs with complementing apertures (not shown) or other support means may also be included. Hydraulic cylinders <NUM> may sometimes be referred to herein as a mid-system.

As shown in <FIG>, an additional set of hydraulic cylinders <NUM> may be included to pivot wheels <NUM> clockwise from the position shown in <FIG> to one in which the wheels contact the ground to raise tracks <NUM> off the ground. This longitudinal disposition of wheels <NUM> would to permit stacker <NUM> to be pulled down the road from one site to another. Shown in phantom in <FIG> is an alternate longitudinal position of one of the mid-wheels 46b, which might be appropriate if the stacker was being operated on uneven or inclined terrain.

<FIG> is similar to <FIG> except that, like <FIG>, shows that in some embodiments the wheels 46a and 46b may be positioned at different lowered positions to facilitate the operation of stacker <NUM> in uneven terrains. As with the depiction in <FIG>, this capability means that the conveyor <NUM> itself can be positioned with the belt substantially horizontal even those the terrain may be slanted in one direction or the other.

The arrangement shown in <FIG> is slightly different in that each wheel <NUM> includes a slightly different leg <NUM> that may be mounted to a vertical post <NUM>. Post <NUM> may be rotatably mounted to bogie <NUM> so that wheels <NUM> may be swiveled from the longitudinal positions shown, for example, in <FIG>, to the radial, lateral position shown in <FIG>, or the <NUM> degree, lateral position. This swiveling may be performed manually or may be provided by a hydraulic motor or hydraulic cylinder drive. Wheels <NUM>, legs <NUM> and posts <NUM> may also be provided with a hydraulic cylinders <NUM> for raising and lowering wheels <NUM>.

Thus, with wheels <NUM> elevated off the ground as shown in <FIG>, post <NUM> may be swiveled to a <NUM> degree lateral position or to a radial position such as that shown in <FIG>. Wheels <NUM> may then be lowered to the ground and, powered by hydraulic cylinders <NUM>, can then raise tracks <NUM> off the ground. Stacker <NUM> then is ready to be maneuvered around the job site if wheels <NUM> are in a lateral position as shown in <FIG> or <FIG> or can be pulled to another site if wheels <NUM> are in a longitudinal position as shown in <FIG> and <FIG>. As described earlier, pegs and complementing apertures (not shown), or other fixation systems, might be included to lock the wheels in their lowered or raised positions.

Once the stacker has reached its destination, in order to prepare the stacker for operations, king pin mount <NUM> would first be disconnected from the fifth wheel of the tractor and would be replaced with pivot point <NUM>. Any positioning pegs or other fixation means in hydraulic cylinders <NUM> would be removed and wheels <NUM> would be raised to their position shown in <FIG> or <FIG>. This permits tracks <NUM> to be lowered to the ground so they now support stacker <NUM>. Hydraulic cylinders <NUM> may then be operated to cause conveyor discharge end <NUM> to be pivoted from the position shown in <FIG>, and hydraulic cylinder <NUM> in front support frames <NUM> is extended so conveyor <NUM> takes the position shown in <FIG>, <FIG> and <FIG>.

If it is desired to move stacker <NUM> radially, either before, after or during this operation to raise the front of the conveyor, wheels <NUM> may be lowered from the raised position to the lowered position shown in <FIG>. This may be done by extending hydraulic cylinders <NUM> until they reach the position depicted in solid lines in <FIG>. This will raise tracks <NUM> off the ground as shown in <FIG>. Or, if the radial position of stacker <NUM> is where it is desired, wheels <NUM> may be maintained in their raised position.

During operations, it is up to the operator to decide if the tracks or the wheels are in contact with the ground; that is, whether the wheels are in their raised position with the tracks in contact with the ground or in their lowered position, with the tracks elevated from contact with the ground. It is also up to the operator to decide, if the wheels are down, whether they be in a radial or longitudinal position. In any event, the operator is provided with a number of options.

As mentioned earlier and as shown in <FIG>, wheels <NUM> or <NUM> may also be at somewhat different lowered positions so that stacker <NUM> will be in a level disposition even if the terrain on which the stacker is operating is not level or perfectly horizontal. In certain circumstances it may even be desired to have one of the wheels <NUM> or <NUM> in a lowered position with the other wheel(s) in a raised position off of the ground. The wheels <NUM> or <NUM> may take these different positions when they are in either their radial or lateral dispositions or if they are extending longitudinally.

With the embodiment of <FIG>, to move stacker radially, either before, after or during the unfolding operation of the conveyor, wheels <NUM> and their legs <NUM> can be swiveled on posts <NUM> and then lowered by hydraulic cylinders <NUM>. This will raise tracks <NUM> off the ground as shown in <FIG>. Or, if the radial position of stacker <NUM> is where it is desired, wheels <NUM> may be maintained in their raised position, depending upon whether the operator wants to perform conveying operations with tracks <NUM> or wheels <NUM> on the ground supporting the stacker. When operations are completed and stacker <NUM> is to be moved to another site, hydraulic cylinders <NUM> raise legs <NUM> and wheels <NUM>, posts <NUM> are swiveled to position wheels <NUM> longitudinally, and the cylinders can then lower the wheels to the position shown in <FIG> and <FIG>. Conveyor discharge end <NUM> is then pivoted through the operation of cylinders <NUM> to the position shown in <FIG> while cylinder <NUM> lowers that front end of the conveyor. In some instances, cylinders <NUM> may need to be operated to raise the rear end of conveyor <NUM> as necessary to facilitate the replacement of pivot point <NUM> with king pin mount <NUM>, and position stacker <NUM> on the fifth wheel of the tractor as shown in <FIG>.

<FIG> depict another embodiment that is different in that it includes a rear wheel <NUM> and associated support structure. Other than the addition of rear wheel <NUM>, the structure of this embodiment may be the same as the other embodiments. Therefore, the numbers used with the other embodiments have been carried over into <FIG>.

Rear wheel <NUM> may be mounted to adjacent the rear portion of stacker <NUM> by a pair of angularly-extending supports <NUM>, which are pivotally mounted to the stacker so that a hydraulic cylinder <NUM> can pivot the rear wheel upwardly and downwardly. In its raised position, depicted in <FIG>, it is up and out of the way. With rear wheel <NUM> in this position, the stacker may be moved about the work site on tracks <NUM>.

Hydraulic cylinder <NUM>, sometimes called a "rear system," is designed to selectively shift rear wheel <NUM> to a lowered position depicted in <FIG>. As rear wheel <NUM> is being lowered into this position by hydraulic cylinder <NUM>, pivot point <NUM> (sometimes called a "foot") is lifted off the ground. Thus, with rear wheel <NUM> in this lowered position, the stacker <NUM> may be moved about in a longitudinal direction, with either the tracks <NUM> or on mid-wheels <NUM> if they are in their longitudinal disposition shown in <FIG>, <FIG>, or <FIG>.

<FIG> depicts rear wheel <NUM> in its lowered, longitudinally disposed position to enable longitudinal movement of the stacker. However, rear wheel <NUM> may be mounted to swivel with respect to the conveyor <NUM> to permit it to be translated to a lateral or radial disposition such as is shown in <FIG>. In this lateral disposition, and with wheels <NUM> (subsequently called mid-wheels to differentiate the rear wheel) in their lateral or radial disposition shown in <FIG>, the stacker may be moved laterally or in a radial arc, depending on the disposition of the mid-wheels. The swiveling capability may be powered by an appropriate hydraulic motor or other means, but the swiveling will normally be manually effected but releasing a lock (not shown) and re-engaging the lock when the swiveling is completed.

As with the earlier embodiments, mid-wheels <NUM> or <NUM> may take somewhat different positions if the stacker is on terrain that is not level. This is true whether or not rear wheel <NUM> is included. As noted earlier, <FIG> show one of the pair of wheels 46b in a somewhat raised position and the other one of the pair of wheels 46a in a lowered position.

It is preferable that the rear wheel <NUM> and mid-wheels <NUM> be provided with means for powering them. This is normally done through hydraulic motors, which are schematically shown at <NUM> (for the rear wheel) and at <NUM> (for the mid-wheels). Depending on whether the rear wheel is being driven at the same speed as the mid-wheels, the stacker may be driven strictly to the side (if the wheels are driven at the same speed) or may be moved in a curved path (if the rear wheel is driven more slowly than the mid-wheels). This provides maximum flexibility to the operator in forming piles of bulk material with the stacker.

<FIG> depict another embodiment of the disclosure that provides a system for elevating the rear end of a portable radial stacker. Because most of the components of this conveyor are the same as those of the previously discussed stacker <NUM>, the same numbers will be used for the components of this conveyor except that they will be in the <NUM> series. The discussion relating to conveyor <NUM> should be considered incorporated into this discussion since many of the components may be used in each system. So, for example, the stacker has been identified generally with the number <NUM>, the conveyor at <NUM>, and the system for raising and lowering the wheels is identified at <NUM>. The hopper is indicated at <NUM>, the main conveyor portion at <NUM>, the discharge end at <NUM>, and the conveyor joint at <NUM>. The centrally disposed pivot pad is shown at <NUM>. A counter-weight <NUM> may be mounted at the rear end of stacker <NUM>.

The pairs of rear, intermediate and front support frames for raising and lowering the main portion <NUM> of the conveyor are shown at <NUM>, <NUM>, and <NUM>, respectively, extending from bogie <NUM>. One of each of the support frames <NUM>, <NUM>, and <NUM> may be disposed on each lateral side of conveyor <NUM> to provide sufficient support and balance, even though only one of each of the support frames is show in the side elevation views. The pair of rear support frames <NUM> may be provided with hydraulic rams <NUM>, and may include pegs and complementing holes (not shown) to fix the support frame in position during operations when the hydraulic rams are not changing the position of the rear support frames. Front support frames <NUM> typically include hydraulic rams <NUM> and may also be provided with pegs and complementing holes (not shown).

A pair of continuous tracks <NUM> and a pair of wheels <NUM> may also be provided. Wheels <NUM> will sometimes be referred to herein as mid-wheels since they are generally at a mid-point of the stacker. Wheels <NUM> are each supported by a leg <NUM>, and a hydraulic cylinder <NUM> (see <FIG>) extends between each of the legs and bogie <NUM>. The hydraulic cylinders <NUM> for changing the position of legs <NUM> may sometimes be referred to herein as a mid-system.

Stacker <NUM> performs in the same fashion as stacker <NUM> except that stacker <NUM> includes features adjacent the rear, hopper end that may not be present in stacker <NUM>. These features facilitate the elevation and support of the rear portion of conveyor <NUM>. This elevation of the rear portion may permit a reduction in the angle of elevation of the stacker to facilitate the stacker being used to stack river rocks, salt and other low-friction bulk material that might slide down a more steeply inclined conveyor. This elevation of the rear portion of the conveyor will enable the stacker to stack low friction material in a relatively high stack without involving a steep angle of elevation; or at least the angle will be shallower than if the rear portion was in a lower position or was resting on the ground.

<FIG> shows a stacker <NUM> being positioned with tracks <NUM> on the ground and wheels <NUM> being elevated. Pivot pad <NUM> includes a pair of extendable, hydraulically actuated legs <NUM> in a lowered position, with conveyor <NUM> extending at an angle of <NUM> degrees. Legs <NUM> may be interconnected by a laterally extending bar <NUM>, the end of which shows in <FIG>. Pivot pad <NUM> is mounted to a central portion of bar <NUM> so that the pair of legs <NUM> provide support from both sides of conveyor <NUM> but the stacker is provided with a single, centrally-disposed pivot pad <NUM>. Hydraulic cylinders <NUM> provide extension and retraction power to legs <NUM>. With a standard-length conveyor <NUM>, the stacker can stack bulk material to a height of <NUM> feet.

<FIG> provides a good comparison, with <FIG>, of the stacking capability of the various positions. <FIG> depicts legs <NUM> after the legs have been adjusted to an extended position, with wheels <NUM> being in a lowered position in which tracks <NUM> are elevated off the ground. In this position, with conveyor <NUM> again at an angle of <NUM> degrees, stacker <NUM> can stack bulk material to a height of <NUM> feet. While this one-foot difference may not seem significant, the additional amount of bulk material that can be in a <NUM>-foot stack as compared to a <NUM>-foot stack is significant.

<FIG> shows the discharge end <NUM> having been lowered through the hydraulic retraction of the front pair of frame members <NUM>. Legs <NUM> are retained in the extended position, with wheels <NUM> being elevated through the action of cylinders <NUM> (see <FIG>), lowering tracks <NUM> to the ground. The resulting angle of inclination is only about <NUM> degree. Because of the extension of legs <NUM> and the resulting elevation of the rear end of conveyor <NUM>, a stack of bulk material about <NUM>½ feet high can be created.

<FIG> shows the discharge end <NUM> having been elevated slightly through the action of front frame members <NUM> to an angle of <NUM> degrees. Again, legs <NUM> are retained in the extended position, except that in this depiction wheels <NUM> have been lowered by cylinders <NUM> to raise tracks <NUM> off the ground. Because of the extension of legs <NUM> and the resulting reduced elevation of the rear end of conveyor <NUM>, a stack of bulk material about <NUM>½ feet high can be created.

<FIG> depicts a variation of stacker <NUM> at <NUM>. Stacker <NUM> includes modified legs <NUM>, which are therefore labeled at <NUM>, being mounted adjacent the rear end of the conveyor. The hopper is shown at <NUM>, and a counter-weight is shown at <NUM>. Legs <NUM> include hydraulic cylinders <NUM> to power the extension and retraction of the legs, only one of the cylinders showing in <FIG> and the other side elevation views. A laterally extending bar <NUM> extends between legs <NUM>, with a central pivot pad <NUM> mounted to it. Cylinders <NUM> and associated components may be designed to be strong enough to permit the rear end of stacker <NUM> to be raised and lowered with hopper <NUM> fully loaded with bulk material. Legs <NUM> pivot at pivot points <NUM> on a stacker frame <NUM> (one pivot point associated with each leg). The pivoting on pivot points <NUM> can be seen by comparing the position of legs <NUM> in <FIG> and <FIG>. While this pivoting is not a necessary feature of the disclosed embodiments (see the absence of the pivoting feature in legs <NUM> in <FIG>), it is a desirable feature. The remaining portions of this embodiment of the stacker may be similar to stacker <NUM>.

<FIG> depict another embodiment of the stacker, with many components that are the same as in stacker <NUM> and <NUM> but have been identified in the <NUM> series: stacker <NUM>; conveyor <NUM>; system for raising and lowering the wheels <NUM>; hopper <NUM>; counterweight <NUM>; main conveyor portion <NUM>; discharge end <NUM>; rear, intermediate and front support frames <NUM>, <NUM>, and <NUM>, respectively; legs <NUM>; leg hydraulic cylinders <NUM>; tracks <NUM>; bogie <NUM>; and pair of mid-wheels <NUM>. A laterally extending bar also may extend between legs <NUM> but that bar does not show in the figures.

Stacker <NUM> is different from stacker <NUM> and <NUM> in that instead of a centrally-disposed pivot pad <NUM>, stacker <NUM> includes a centrally-disposed pivotable rear wheel <NUM>. This rear wheel may be mounted to a laterally-extending bar, which, again, is not shown in the figures. Rear wheel <NUM> is typically rotatably and pivotally mounted adjacent the rear portion of the conveyor <NUM>, under hopper <NUM>. Legs <NUM> are designed to pivot on a pivot point <NUM> so that they may be vertically disposed when extended, as shown in <FIG>. An arced pivot securement member <NUM> may be provide to assist in securing each of the legs <NUM> in a variety of pivoted positions. One or more pegs (not shown) may be mounted into one of a plurality of holes in pivot securement member <NUM>. Legs <NUM> may be set up for manual pivoting, or power means may be provided.

When legs <NUM> and rear wheel <NUM> are in their raised, longitudinally extended position depicted in <FIG>, the wheel may be used to roll the rear end of stacker <NUM> in a longitudinal direction such as when tracks <NUM> are on the ground and wheels <NUM> are in their raised position. Or, a longitudinal disposition of rear wheel <NUM> will also permit such longitudinal movement when mid-wheels <NUM> are in their lowered, longitudinal positions. With legs <NUM> retracted as shown in <FIG>, conveyor <NUM> typically extends at an angle in the range of <NUM>-<NUM> degrees.

<FIG> shows stacker <NUM> in a slightly elevated position, after leg hydraulic cylinder <NUM> has extended leg <NUM>, with tracks <NUM> elevated, and wheel <NUM> on the ground in a longitudinal disposition. As with stacker <NUM> depicted in <FIG>, the elevation of the rear end of conveyor <NUM> means that the conveyor can extend at a lower degree of elevation than if the rear end were in the lowered position depicted in <FIG>.

<FIG> depicts rear wheel <NUM> in a lateral position so that with mid-wheels <NUM> in the depicted lowered position with tracks <NUM> in a raised position, the entire stacker <NUM> can be rolled in a lateral direction.

<FIG> depict another embodiment of the stacker, with many components that are the same as in stacker <NUM> and <NUM> but have been identified in the <NUM> series: stacker <NUM>; conveyor <NUM>; system for raising and lowering mid-wheels <NUM>; hopper <NUM>; counterweight <NUM>; discharge end <NUM>; pivot pad <NUM>; rear, intermediate and front support frames <NUM>, <NUM>, and <NUM>, respectively; legs <NUM>; pivot points <NUM>; leg hydraulic cylinders <NUM>; tracks <NUM>; laterally-extending bar <NUM>; bogie <NUM>; pair of mid-wheels <NUM>; mid-wheel support legs <NUM>; and hydraulic cylinders for controlling the position of the mid-wheels <NUM>. Legs <NUM> may be mounted to the frame of conveyor <NUM> via pivot points so the legs can remain vertical but that capability has not been included in the embodiment depicted in <FIG>.

Stacker <NUM> includes the capability of elevating the rear end of hopper <NUM> so that the hopper may be maintained at a predetermined degree of inclination regardless of the degree of inclination of the conveyor. That predetermined degree of inclination is typically horizontal, that is, with no inclination angle. However, there may be instances where some inclination is desirable. There may be other instances, such as when mulch is being conveyed, that the hopper is tilted downwardly by, say, <NUM>-<NUM> degrees. This downward inclination is intended to be within the definition of "inclination" or "incline" as used herein.

The angle maintenance may in some instances be set up to be automatic so that when the elevation of conveyor <NUM> is changed, the inclination of hopper <NUM> will be changed with respect to the conveyor inclination. This can be done through installation of a level sensor, which could control a pair of hopper hydraulic cylinders designed to control the elevation of the rear end of the hopper. This could be the same type of valve currently used to maintain the true vertical position of the stacker while operating the stacker on a side of a sloping hill. However, the adjustment of elevation of the hopper is normally performed manually by the operator. Raising and lowering of the angle may be controlled remotely via a remotely-controlled solenoid valve.

As with the prior embodiments of stacker <NUM>, <NUM>, and <NUM>, stacker <NUM> may include, and typically does include, the capability of leg <NUM> being extendable through the action of hydraulic cylinder <NUM>.

The depicted system for adjusting the inclination of hopper <NUM> includes a pair of hopper hydraulic cylinders <NUM>, one on each side of the hopper. Hopper hydraulic cylinders <NUM> may include a plurality of holes <NUM> in which pegs (not shown) may be placed to lock the position of a pair of hopper legs <NUM> at a given length. Hopper legs <NUM> are pivotally mounted to the underside of hopper <NUM> at <NUM>, and pivotally mounted to the underside of the rear of stacker <NUM> at <NUM>. Hopper <NUM> is pivotally mounted to the upper side of stacker <NUM> at <NUM>. Hopper <NUM> may be conventional in other respects.

Claim 1:
A portable radial stacker (<NUM>) for stockpiling bulk material, comprising:
a linear conveyor (<NUM>) having a rear portion and a front portion mounted to a frame and being designed to carry bulk material from a low position adjacent the rear portion to a higher position adjacent the front portion;
a hopper (<NUM>) mounted to the rear portion of the conveyor;
a contact (<NUM>) mounted to the frame at the rear portion of the conveyor and being designed to contact the ground to facilitate pivoting of the conveyor; and
a pair of mid-wheels (<NUM>) mounted to the frame that can be positioned in a radial direction to facilitate radial shifting of the stacker;
characterized in that:
the contact is adjustable in length; and
at least one hydraulic jack (<NUM>) is mounted to the contact for selectively elevating the rear portion of the conveyor to increase the elevation of the low position to reduce an angle of elevation of the conveyor.