Patent Publication Number: US-2007101897-A1

Title: Axle for radial stacker

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Application No. 60/734,239 filed Nov. 7, 2005. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
      Not Applicable  
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC  
      Not Applicable  
     BACKGROUND OF THE INVENTION  
      (1) Field of the Invention  
      The present invention relates to an axle assembly for use with a portable radial stacker. In particular, the invention relates to an axle assembly having wheel sets which pivot to enable the wheel sets to be used to transport or operate the portable radial stacker.  
      Radial stackers are well known in the art. Radial stackers or radial stacking conveyors are conveyor systems where the off-load end of the conveyor can be pivoted, radially about a pivot point. Radial stackers are used to stockpile material. The ability of a radial stacker to pivot the off-load end allows the radial stacker to off-load the material in an arcuate path which increases the amount of material which can be stockpiled in a specific area.  
      Portable radial stackers are also well known in the art. Portable radial stackers have wheels and can be transported from site to site by another vehicle. The wheels of some portable radial stackers can be converted from transport mode to operational mode. When the wheels are in transport mode, the wheels allow the radial stacker to be transported or towed. In operational mode, the wheels are positioned to allow the off-load end of the radial stacker to move radially. To transport a radial stacker using public roads, the radial stacker must meet certain width restrictions. However, during use of the radial stacker, the wheels must be spaced apart to provide sufficient support to prevent the radial stacker from tipping over. As the length of the radial stacker is increased, the spacing between the wheels and thus the width of the radial stacker is increased. For larger radial stackers, such stability cannot be accomplished with wheels which have a spacing which allows transport on public roads. To solve this problem, some portable radial stackers have two (2) sets of wheels. One (1) set allows for transport of the radial stacker. The other set of wheels allows for radially moving the radial stacker. The addition of a second set of wheels necessarily makes the radial stacker more expensive.  
      (2) Description of the Related Art  
      The related art has shown various types of portable radial stackers having various types of axle assemblies. Illustrative are U.S. Pat. No. 4,135,614 to Penterman et al.; U.S. Pat. No. 4,427,104 to Reid, Jr.; U.S. Pat. No. 5,515,961 to Murphy et al.; U.S. Pat. No. 5,833,043 to Schmidgall et al.; and U.S. Pat. No. 6,186,311 to Conner.  
      Penterman et al. describes an axle assembly for use with a portable radial stacker. The axle assembly has a pair of wheel assemblies which includes two wheels. Each wheel assembly may be rotated between the traveling position and the operating position. A motor assembly is affixed to one wheel of at least one wheel assembly to drive the stacker in the operating position about the arc to produce the radial shaped stack of material.  
      Reid Jr. describes a portable radial stacker having a foldable conveyor and an extendable axle assembly. The axle assembly includes a central horizontal transverse axle member with a swing axle member at each end. Wheels are rotatably mounted on the swing axles. Hydraulic motors are provided to drive the wheels when the stacker is in the operating configuration. A pivotable joint between the central axle member and the swing axle member permits the swing axle member to be pivoted from an operating configuration to a transport configuration. In the operating configuration, the swing axle extends directly in line with the central traverse horizontal axle member providing a wide base to support the radial stacker. In the transport configuration the wheels are located close together behind the central traverse axle member and are oriented for rotation about an axis perpendicular to the length of the conveyor. To move the swing axles from the operating configuration to the travel configuration, each of the ends of the central axle member are lifted in turn and the associated swing axle is swung rearwardly. As each swing axle is rotated rearwardly, the associated wheel remains at essentially the same distance above the ground and the swing axle will rotate from a forwardly tilting orientation to a nearly upright attitude.  
      Murphy et al. and Schmidgall et al. both describe a portable radial stacker having two sets of wheels. One set is a set of transport wheels and the other set is a set of radial travel wheels. When the radial stacker is being transported the radial travel wheels which are mounted to outriggers are retracted or pivoted upward off the ground. When the radial stacker is in operational mode, the radial travel wheels are extended downward.  
      Conner describes a self-transporting conveyor system which includes a pair of stacking conveyors and a pair of transfer conveyors. Each of the stacking conveyors has a separate axle and wheel set for road transport and to enable sideways movement of the stacking conveyor. One of the wheels is mounted on a telescoping portion of the axle. When extended, the telescoping wheels provide stability when the stacker is in the operating position. In the retracted position, the telescoping wheels enable the stacker to meet highway width standards. The wheels are supported on the axles by vertical axis pivots or king pins. In one (1) position, the wheel has its axis parallel to the axis of the axle. In the other position, the wheel has its axis nearly perpendicular to the axis of the axle. To move the wheels from the transport mode to the operational mode, the wheels are jacked up and rotated about the king pin and then locked in position and lowered to the ground. The wheels are jacked up and pivoted one at a time. To extend the wheel, the wheel is jacked up off the ground and then the wheel is extended by operation of the hydraulic cylinder, the wheel is then pivoted into operational mode.  
      Also of some interest is U.S. Pat. No. 3,334,912 to Mauck which describes a vehicle wheel support assembly for trailers and other similar types of vehicles where the sets of wheels of the support assemblies are pivotably mounted to pivot in a generally vertical plane to compensate for unevenness in the road surface. The set of wheels may also be pivotable in a generally horizontal plane to aid in the turning of trailers of excessive lengths.  
      Only of minimal interest is U.S. Pat. No. 6,591,971 to Sheahan which describes a silage cutter and loader apparatus. The apparatus includes one or more drive wheel assemblies which are able to rotate about a vertical axis, have a range of travel of at least ninety degrees and are able to turn parallel or perpendicular to the longitudinal axis of the apparatus which allows for steering the apparatus.  
      There remains a need for an axle assembly for a portable radial stacker which has a pair of wheel sets to transport and operate the radial stacker where the wheel sets of the axle assembly can be easily moved from the transport mode to operational mode and where the wheel sets meet the width restrictions in transport mode and provide support for the radial stacker in operational mode.  
     BRIEF SUMMARY OF THE INVENTION  
      An axle assembly for use with a portable radial stacker which allows a single wheel set on each end of the axle assembly to be used to transport and operate the radial stacker. The wheel sets of the axle assembly can be pivoted and extended so that a width of the axle assembly in the transport mode is less than a width of an axle assembly in the operational mode. The wheel sets can be pivoted and extended without the use of a jack or other device to lift the axle assembly. The axle assembly includes an axle frame having pivot brackets at each end with wheel sets pivotably mounted by connector arms to the pivot brackets. The pivot brackets pivot on a vertical axis about the end of the axle frame. The wheel sets are moved from the transport mode with the axis of rotation of the wheel sets essentially perpendicular to the longitudinal axis of the radial stacker and essentially parallel to the longitudinal axis of the axle frame, to the unextended, pivoted position with the axis of rotation of the wheel sets essentially parallel to the longitudinal axis of the radial stacker and essentially perpendicular to the longitudinal axis of the axle frame by pivoting the pivot brackets about the ends of the axle frame. The connector arms pivot on the pivot brackets about a horizontal axis. Pivoting the connector arms on the pivot brackets enables the wheel sets to be moved from the unextended, pivoted position to the extended, operational position.  
      First piston cylinders can be used between the axle frame and the pivot brackets to pivot the pivot brackets about the vertical axis. In an alternate embodiment, where the wheel sets include a pair of wheels, the wheels of the wheels set have motors which rotate the wheels in opposite directions to rotate the pivot brackets. Second piston cylinders can be used between the first end of the connector arms and the pivot brackets to pivot the wheel sets between the unextended and extended positions. Motors can also be provided on the wheels of the wheel sets to rotate the wheels to move the wheel sets between the unextended and extended positions.  
      To move the wheel sets from the travel mode to the operational mode, the pivot brackets are pivoted so that the axis of rotation of the wheel sets are essentially parallel to the longitudinal axis of the radial stacker. Next the connector arms are pivoted on the pivot brackets to move the wheel sets away from the axle frame and away from the radial stacker to increase the width of the axle assembly to provide additional support for the radial stacker during operation. During extension of the wheel sets, as the wheel sets move below the pivot point of the pivot brackets and the connector arms, the axle frame and the radial stacker are raised upward slightly and then lowered back down as the wheel sets reach the fully extended position. Once the wheel sets are in the extended position, the pivot brackets can then be rotated back slightly so that the axis of rotation of the wheel sets is not parallel to the longitudinal axis of the radial stacker but is at an angle to the longitudinal axis so that when the wheels rotate, the off-load end of the radial stacker moves in an accurate path about the infeed end of the radial stacker. The pivoting ability of the wheel sets on the pivot brackets can also be used to move the radial stacker in the accurate path during operation. To move the radial stacker, the brake on one wheel set is engaged. Next the wheel set is pivoted from the extended position to the unextended position. However, since the wheel set is unable to rotate, the wheel set does not move, rather the remainder of the radial stacker moves toward the braked wheel set. Thus moving the radial stacker in a direction toward the wheel set. Next the brake for the wheel set is disengaged and the brake for the opposite wheel set is engaged. The unbraked wheel set is then moved into the extended position.  
      The present invention relates to an axle assembly for use with a radial stacker having opposed ends with a conveyor extending between the ends forming a longitudinal axis of the radial stacker, which comprises an axle frame having opposed ends and configured to be mounted on the radial stacker and a pair of wheel sets pivotably mounted on ends of the axle frame such that each wheel set pivots about one end of the axle frame between a first position with an axis of rotation of the wheel set essentially perpendicular to the longitudinal axis of the radial stacker and a second position with the axis of rotation of the wheel set essentially parallel to the longitudinal axis of the radial stacker and pivots away from and towards the axle frame.  
      Further, the present invention relates to an axle assembly for use with a radial stacker having opposed ends with a conveyor extending between the ends forming a longitudinal axis of the radial stacker, which comprises an axle frame having opposed ends forming a longitudinal axis of the axle frame and configured to be mounted on the radial stacker, a pair of brackets having a first portion and a second portion and pivotably mounted on each of the ends of the axle frame wherein each bracket is able to pivot between a first position with the second portion of the bracket essentially perpendicular to the longitudinal axis of the axle frame and a second position with the second portion of the bracket essentially parallel to the longitudinal axis of the axle frame, and a pair of wheel sets pivotably mounted on the second portion of each of the brackets wherein each wheel set is able to pivot on the second portion of the bracket between an unextended position with the wheel set adjacent the first portion of the bracket and an extended position with the wheel set spaced apart from the first portion of the bracket.  
      Still further, the present invention relates to an axle assembly for use with a radial stacker, which comprises an axle frame having opposed ends forming a longitudinal axis of the axle frame and configured to be mounted on the radial stacker, wheel sets, each wheel set having an axis of rotation and movably mounted on the ends of the axle frame, a means for moving the wheel sets from a first position with the axis of rotation of the wheel sets essentially parallel to the longitudinal axis of the axle frame to a second position with the axis of rotation of the wheel sets essentially perpendicular to the longitudinal axis of the axle frame, and means for moving the wheel sets toward or away from the axle frame.  
      Further still, the present invention relates to a method for moving the wheels of an axle assembly for a radial stacker from a travel mode to an operational mode, the radial stacker having opposed ends forming a longitudinal axis of the radial stacker, the method which comprises the steps of providing the axle assembly including an axle frame having opposed ends with a pair of brackets pivotably mounted on each of the ends of the axle frame, and a pair of wheel sets pivotably mounted on each of the brackets, positioning the pair of wheel sets in the travel mode so that an axis of rotation of each of the wheel sets is essentially perpendicular to the longitudinal axis of the radial stacker, pivoting the brackets such that the axis of rotation of each of the wheel sets is essentially parallel to the longitudinal axis of the radial stacker, and pivoting each of the wheel sets on the brackets such that wheels of each of the wheel sets rotate about the axis of rotation of the wheel sets and the wheel sets are moved from an unextended position adjacent the axle frame outward away from the axle frame to an extended position.  
      Further still, the present invention relates to a method for operating a radial stacker having opposed first and second ends forming a longitudinal axis of the radial stacker which comprises the steps of providing an axle assembly mounted on the radial stacker having an axle frame with opposed first and second ends with first and second wheel sets pivotably mounted on the first and second ends of the axle frame respectfully so that the wheels sets are able to pivot toward and away from the axle frame, positioning the wheel sets in a fully extended position away from the axle frame, engaging a brake of the first wheel set, pivoting the first wheel set such that the first wheel set is moved from the extended position to an unextended position wherein the brake prevents the first wheel set from moving which moves the radial stacker toward the first wheel set to move the first wheel set from the extended position to the unextended position, disengaging the brake of the first wheel set, engaging the brake of the second wheel set, and pivoting the first wheel set so that the first wheel set moves from the unextended position to the extended position.  
      The substance and advantages of the present invention will become increasingly apparent by reference to the following drawings and the description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of the portable radial stacker  100  with the wheel sets  34  in the transport mode.  
       FIG. 2  is a view of the axle assembly  10  with a partial exploded view of the first wheel assembly  20 .  
       FIG. 3  is a perspective view of the axle assembly  10  with the wheel assemblies  20  and  50  in the transport mode.  
       FIG. 4  is a partial perspective view of the portable radial stacker  100  showing the second wheel assembly  50  in the partially, pivoted position.  
       FIG. 5  is a front perspective view of the axle assembly  10  with the first wheel assembly  20  in the transport mode and second wheel assembly  50  in the partially, pivoted position.  
       FIG. 6  is a front perspective view of the axle assembly  10  with the first and second wheel assemblies  20  and  50  in the pivoted, unextended position.  
       FIG. 7  is a partial front perspective view of the portable radial stacker  100  with the second wheel assembly  50  in the pivoted, unextended position.  
       FIG. 8  is a front perspective view of the axle assembly  10  with the first wheel assembly  20  in the pivoted, unextended position and the second wheel assembly  50  in the pivoted, partially extended position.  
       FIG. 9  is a partial front perspective view of the axle assembly showing the second wheel assembly  50  in the pivoted, extended position.  
       FIG. 10  is a partial front view of the axle assembly  10  with the first and second wheel assemblies  20  and  50  in the pivoted, operational mode.  
       FIG. 11  is a perspective view of the axle assembly  10  with the first and second wheel assemblies  20  and  50  in the pivoted, extended operational mode.  
       FIG. 12  is an exploded view of the first wheel set  34  showing the wheels  36 , the motor  44  and brake  46 .  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      All patents, patent applications; government publications, government regulations, and literature references cited in this specification are hereby incorporated herein by reference in their entirety. In case of conflict, the present description, including definitions, will control.  
      The present invention relates to an axle assembly  10  for use with a portable radial stacker  100 . In general, radial stackers or radial stacking conveyors  100  include a frame  102  with an endless conveyor belt  104  mounted over drive rollers and follower rollers along a top of the frame  102 . The radial stacker  100  includes an infeed end  100 A and an off-load end  100 B with the conveyor belt  104  extending therebetween. The ends  100 A and  100 B of the radial stacker  100  form the longitudinal axis B-B of the radial stacker  100  ( FIG. 1 ). During transport, the frame  102  of the radial stacker  100  at the infeed end  100 A is connected to a towing vehicle (not shown). During operation, the infeed end  100 A of the radial stacker  100  is adjacent the ground surface and the off-load end  100 B is spaced above the ground surface. The radial stacker  100  pivots in an arc about the infeed end  100 A to stockpile the material in an arcuate stack. In one (1) embodiment, the frame  102  is telescoping such that the length of the radial stacker  100  can be extended during operation. The length of the radial stacker  100  is reduced to allow for transport. In one (1) embodiment, the frame  102  of the radial stacker  100  adjacent the off-load end  100 B pivots so that the length of the radial stacker  100  can be shortened by pivoting the off-load end  100 B approximately 180° so that the off-load end  100 B is adjacent a center portion of the radial stacker  100 . Various types of portable radial stackers  100  are well known in the art and include telescoping and foldable radial stackers such as described in U.S. Pat. No. 4,427,104 to Reid, Jr.; U.S. Pat. No. 6,056,252 to Johannsen; and U.S. Pat. No. 6,360,876 to Nohl et al. which are incorporated herein by reference in their entirety.  
      The axle assembly  10  is mounted to the bottom of the frame  102  of the radial stacker  100  on a side opposite the conveyor belt  104 . The axle assembly  10  allows for transporting the radial stacker  100  and allows for moving the radial stacker  100  in an arcuate path during operation. The axle assembly  10  of the present invention may be retrofitted onto existing radial stackers  100  or it may be included on newly manufactured radial stackers  100 . The axle assembly  10  is mounted closer to the off-load end  100 B of the radial stacker  100  than the infeed end  100 A of the radial stacker  100 . In one (1) embodiment, the axle assembly  10  is positioned so that approximately 55% of the radial stacker  100  extends between the infeed end  100 A and the axle assembly  10 .  
      The axle assembly  10  can be connected to the frame  102  of the radial stacker  100  using a variety of methods and structures. In one (1) embodiment, the axle assembly  10  is mounted to the frame  102  using an axle frame  12  and a lower frame  14 . The axle frame  12  of the axle assembly  10  is mounted to the frame  102  of the radial stacker  100 . The axle frame  12  has opposed first and second ends  12 A and  12 B forming the longitudinal axis A-A of the axle frame  12  ( FIG. 3 ). The axle frame  12  has a length such that when the axle assembly  10  is mounted on the frame  102  of the radial stacker  100 , the ends  12 A and  12 B of the axle frame  12  extend beyond the sides of the frame  102  of the radial stacker  100 . In one (1) embodiment, the axle frame  12  extends perpendicular to the conveyor belt  104  of the radial stacker  100 . In one (1) embodiment, the lower frame  14  of the axle assembly  10  extends essentially parallel to the axle frame  12  and is connected to the axle frame  12  by vertical connectors that extend essentially perpendicular to the axle frame  12  and the lower frame  14 . In one (1) embodiment, the lower frame  14  is shorter in length than the axle frame  12  such that the lower frame  14  does not interfere with the wheel assemblies  20  and  50  when the wheel assemblies  20  and  50  are rotated from the transport position to the initial, pivoted, unextended position. The frame  102  of the radial stacker  100  is attached to the lower frame  14  of the axle assembly  10  by struts. The struts extend outward from the lower frame  14  at an angle and are connected to the underside of the frame  102  of the radial stacker  100  opposite the conveyor belt  104 . The struts enable the axle assembly  10  to rotate the radial stacker  100  by moving the rotating force outward away from the axle assembly  10  and the wheels  36  and toward the ends  100 A and  100 B of the radial stacker  100 .  
      The axle assembly  10  includes first and second wheel assemblies  20  and  50  which are pivotably mounted on each end  12 A and  12 B of the axle frame  12 . The wheel assemblies  20  and  50  are identical and therefore, only the first wheel assembly  20  will be discussed in detail. The first wheel assembly  20  includes a pivot bracket  22 , a connector arm  30  and a first wheel set  34  ( FIG. 2 ). The pivot bracket  22  is pivotably mounted on the first end  12 A of the axle frame  12  and includes a first portion  24  and a second portion  26 . The first portion  24  of the pivot bracket  22  is pivotably mounted on the axle frame  12 . To mount the pivot bracket  22  on the axle frame  12 , a first pivot pin  28  is inserted through a hole in the first portion  24  and through a hole in the first end  12 A of the axle frame  12  to pivotably mount the pivot bracket  22  to the axle frame  12 . The first pivot pin  28  extends essentially vertical to the ground surface which allows the pivot bracket  22  to rotate about a vertical axis in a plane essentially horizontal to the ground surface. In one (1) embodiment, a spacer (not shown) is positioned between the first portion  24  of the pivot bracket  22  and the axle frame  12  to space the pivot bracket  22  away from the axle frame  12  to reduce friction during pivoting of the pivot bracket  22 . In one (1) embodiment, the spacer is constructed of a lower friction material such as Teflon®. The second portion  26  of the pivot bracket  22  extends outward from the first portion  24  in a direction opposite and below the first portion  24 . The second portion  26  has a pair of spaced apart legs  26 A which extend outward essentially parallel to the first portion  24 . When the first portion  24  is aligned with the axle frame  12 , the legs  26 A of the second portion  26  extend outward essentially parallel to the axis A-A of the axle frame  12 . The first and second portions  24  and  26  of the pivot bracket  22  are positioned with respect to each other such that when the pivot bracket  22  pivots on the axle frame  12 , the second portion  26  is spaced beyond the end  12 A of the axle frame  12  and does not contact the axle frame  12 .  
      The connector arm  30  has a first end  30 A and a second end  30 B and is pivotably mounted between the legs  26 A of the second portion  26  of the pivot bracket  22 . To mount the connector arm  30  to the pivot bracket  22 , a second pivot pin  32  is inserted through the first leg  26 A of the second portion  26  of the pivot bracket  22 , through the connector arm  30  and through the second leg  26 A of the second portion  26  of the pivot bracket  22 . In one (1) embodiment, the pivot pin  32  is constructed as part of the connector arm  30  and extends outward from each side of the connect arm  30 . The connector arm  30  is pivotably mounted to the pivot bracket  22  adjacent to the first end  30 A of the connector arm  30 . In one (1) embodiment, when the connector arm  30  is positioned between the legs  26 A of the second portion  26  of the pivot bracket  22 , the first end  30 A of the connector arm  30  extends upward beyond the legs  26 A of the second portion  26  of the pivot bracket  22  and the second end  30 B of the connector arm  30  extends downward below the legs  26 A. In one (1) embodiment, the first end  30 A of the connector arm  30  extends beyond the first portion  24  of the pivot bracket  22  and the axle frame  12 .  
      The second end  30 B of the connector arm  30  is connected to the first wheel set  34 . In one (1) embodiment, the first wheel set  34  includes a pair of wheels  36  connected together by an axle  38 . However, it is understood that the first wheel set  34  could include a single wheel or a plurality of wheels connected together by one (1) or more axles  38 . The wheels  36  can be similar to wheels well known in the art. In one (1) embodiment, the wheels  36  are rotatably mounted on the axle  38  and the axle  38  is fixably mounted on the second end  30 B of the connector arm  30 . In another embodiment, the wheels  36  are fixably mounted on the axle  38  and the axle  38  is rotatably mounted to the second end  30 B of the connector arm  30 . The axle  38  can be mounted to the connector arm  30  by any well known means. In one (1) embodiment, the axle  38  has opposed ends and includes a gear drive at each end. The gear drive allows for securing the wheels  36  onto the axle  38 . In one (1) embodiment, one (1) of the wheels  36  of the first wheel set  34  has a motor  44  for moving the wheel  36 . In one (1) embodiment, both of the wheels  36  of each of the wheel sets  34  are provided with a motor  44  to allow the axle assembly  10  to have four wheel drive. In one (1) embodiment, each wheel  36  of the wheel sets  34  of the radial stacker  100  is equipped with a brake  46  ( FIG. 12 .) In one (1) embodiment, the brake  46  is a hydraulic brake. In another embodiment, the brake is an air brake.  
      In one (1) embodiment, the first wheel assembly  20  is provided with a first piston cylinder  40  for pivoting the pivot bracket  22  of the wheel assembly  20  on the axle frame  12  about the first pivot pin  28  to change the orientation of the first wheel set  34  from the transport position or transport mode to the radial movement position or operational mode (FIGS.  4  to  6 ). The first piston cylinder  40  is mounted between the axle frame  12  and the second portion  26  of the pivot bracket  22  ( FIG. 2 ). In one (1) embodiment, the first piston cylinder  40  is a hydraulic piston. In another embodiment where the first wheel set  34  has at least two (2) wheels  36 , the pivot bracket  22  is pivoted by rotation of the wheels  36  of the wheel set  34 . In this embodiment, motors  44  are connected to each of the wheels  36  of the first wheel set  34  ( FIG. 12 ). The motors  44  rotate the wheels  36  in different directions which pivots the pivot bracket  22  on the axle frame  12 . In one (1) embodiment, the motors  44  are hydraulic motors. In one (1) embodiment, each wheel  36  has a separate motor  44 . It is understood that a variety of mechanisms well known in the art such as a linear motor or screw drive can be used to pivot the pivot bracket  22  and the first wheel set  34  about the first pivot pin  28 .  
      In one (1) embodiment, the wheel assembly  20  includes a second piston cylinder  42  for pivoting the first end  30 A of the connector arm  30  on the second pivot pin  32  toward and away from the axle frame  12  to move the first wheel set  34  on the second end  30 B of the connector arm  30  away from and toward the axle frame  12  and the frame  102  of the radial stacker  100 . The second piston cylinder  42  is connected at one (1) end to the first portion  24  of the pivot bracket  22  and at the other end to the first end  30 A of the connector arm  30  ( FIG. 3 ). In one (1) embodiment, the second piston cylinder  42  is a hydraulic piston. In another embodiment, where the first wheel set  34  has motors  44 , rotation of the wheels  36  of the wheel set  34  can be used to move the wheel set  34  from the unextended to the extended position. It is understood that any type of mechanism such as a screw drive or a linear motor well known in the art could be used to pivot the connector arm  30  to move the first wheel set  34  away from and toward the frame  102  of the radial stacker  100 .  
      In one (1) embodiment, where the wheels  36  of the wheel set  34  have motors  44 , the motor  44  is used to rotate the first wheel set  34  to position the radial stacker  100  and to rotate the off-load end  100 B of the radial stacker  100  in an arcuate path during operation. Any type of motor well known in the art can be used to rotate the wheels  36 . In one (1) embodiment, the motors used to pivot the first wheel set  34  and the motor  44  used to rotate the wheels  36  of the first wheel set  34  is the same motor  44 .  
      To transport the radial stacker  100 , the wheel sets  34  are positioned in the initial unpivoted, unextended transport mode ( FIGS. 1 and 3 ). Since the first and second wheel assemblies  20  and  50  are similarly positioned, only the positioning of the first axle assembly  20  will be described in detail. In one embodiment, the position with the wheel assemblies  20  and  50  are changed simultaneously. In one (1) embodiment, in the initial unpivoted, unextended transport mode, the second portion  26  of the pivot bracket  22  is perpendicular to the longitudinal axis A-A of the axle frame  12  and the second portion  26  of the pivot bracket  22  extends outward from the axle frame  12  toward the infeed end  100 A or towing end of the radial stacker  100 . In this position, the axis of rotation C-C of the wheels  36  is essentially aligned with the longitudinal axis A-A of the axle frame  12  and is essentially perpendicular to the longitudinal axis B-B of the radial stacker  100 . In one (1) embodiment, in the transport mode, the wheel sets  34  extend partially below the axle frame  12 . In one (1) embodiment, the side of the support arm  30  adjacent the axle frame  12  has a brace. When the wheel set  34  is in the unextended position, the axle frame  12  contacts and rests on the brace which transfers the load of the radial stacker  100  from the axle frame  12  to the support arm  30  and the wheel set  34  and away from the second pivot pin  32 . In the transport mode, the total width of the axle assembly  10  is such that the radial stacker  100  can be transported on public roads. In one (1) embodiment, the total width of the axle assembly  10  is the transport mode is less than 12 feet (3667 mm). To transport the radial stacker  100 , the front end or infeed end  100 A is connected to a towing vehicle such as a fifth wheel vehicle. When the radial stacker  100  is being transported, the wheels  36  of the first wheel set  34  are able to rotate fully. To operate the radial stacker  100  to move or stockpile material, the off-load end  100 B of the radial stacker  100  is positioned adjacent the stacking area and the infeed end  100 A is positioned adjacent the material to be moved. In one (1) embodiment, the motors  44  on the wheels  36  are used when the first wheel set  34  is in the initial unpivoted, unextended transport position to adjust or fine tune the position of the radial stacker  100 . Once the radial stacker  100  is correctly positioned, the wheel sets  34  are rotated into the unextended, pivoted position or pivoted mode ( FIG. 6 ).  
      To move the first wheel set  34  to the unextended, pivoted position, the pivot bracket  22  is rotated on the first pivot pin  28 . In one (1) embodiment, the pivot bracket  22  is moved so that the legs  26 A of the second portion  26  of the pivot bracket  22  are essentially aligned with the longitudinal axis A-A of the axle frame  12  and the axis of rotation C-C of the wheels  36  is perpendicular to the longitudinal axis A-A of the axle frame  12  and essentially parallel to the longitudinal axis B-B of the radial stacker  100 . In this position, the wheels  36  are located partially below the axle frame  12  and partially below the pivot bracket  22  ( FIG. 6 ). However, the pivot bracket  22  can be pivoted such that the legs  26 A of the second portion  26  of the pivot bracket  22  are at an angle to the longitudinal axis A-A of the axle frame  12 . In one (1) embodiment, the first piston cylinder  40  is extended to pivot the pivot bracket  22 . In another embodiment, where motors  44  are connected to each of the wheels  36 , to change the orientation of the first wheel set  34 , the wheels  36  of the first wheel set  34  are rotated in different directions as necessary to move the wheel assembly  20  on the first pivot pin  28 . In one (1) embodiment, as the pivot bracket  22  and first wheel set  34  are pivoted, the wheels  36  rotate freely to make movement easier. In one (1) embodiment, the wheels  36  slide along the ground surface during pivoting of the pivot bracket  22  and the first wheel set  34 . Once in the correct position, the pivot bracket  22  is locked in place.  
      Next, the wheel assemblies  20  and  50  are pivoted into the extended position or operational mode ( FIG. 10 ). The connector arm  30  is pivoted about the second pivot pin  32  to move the first wheel set  34  away from the frame  102  of the radial stacker  100 . In one (1) embodiment, the second piston cylinder  42  is retracted to pull the first end  30 A of the connector arm  30  toward the first portion  24  of the pivot bracket  22  and to move the wheel set  34  on the second end  30 B of the connector arm  30  away from the first portion  24  of the pivot bracket  24 . In another embodiment, the motors  44  are used to rotate the wheels  36  of the wheel set  34  to move the wheel set  34  between the unextended and extended position. As the first wheel set  34  moves from the initial, unextended position with the axis of rotation C-C of the wheels  36  essentially perpendicular to the longitudinal axis A-A of the axle frame  12 , the length of the connector arm  30  from the pivot point to the wheel set  34  and the diameter of the wheels  36  may cause the radial stacker  100  to be raised slightly away from the ground surface as the wheel set  34  moves directly underneath the second pivot pin  32  and the connector arm  30  is perpendicular to the longitudinal axis A-A of the axle frame  12 . As the first wheel set  34  continues to move toward the extended position, the radial stacker  100  lowers to the “at rest” position. The positioning of the pivot bracket  24  such that the axis of rotation C-C of the wheels  36  is essentially perpendicular to the longitudinal axis A-A of the axle frame  12 , enables the wheels  36  to easily rotate during movement of the first wheel set  34  to the extended position. In the embodiment where the pivot bracket  24  is pivoted to so that the axis of rotation C-C is at an angle not perpendicular to the axis A-A of the axle frame  12 , the amount of force needed to move the first wheel set  34  to the extended position is greater since the wheels  36  create friction with the ground surface. When the first wheel set  34  is in the extended position, the first wheel set  34  is spaced apart from the frame  102  of the radial stacker  100  and provides additional support or stabilization to the radial stacker  100  as outriggers ( FIG. 10 ). The spacing between the wheel sets  34  during radial movement must be sufficient to prevent the radial stacker  100  from tipping laterally when it is in its fully extended position in length and height. In one (1) embodiment, the connector arm  30  is of such a length that when the wheel sets  34  are in the fully extended, operational position, the wheel sets  34  are spaced apart from the ends  12 A and  12 B of the axle frame  12  approximately 3 ft. (914 mm). Once the wheel sets  34  are in the fully, extended position, the wheel sets  34  are rotated back slightly about the first pivot pin  28  so that the axis of rotation C-C of the wheels  36  is no longer perpendicular to the axis A-A of the axle frame  12  ( FIG. 10 ). Pivoting the wheel sets  34  backwards enables the radial stacker  100  to move in an arcuate path about the infeed end  100 A of the radial stacker  100 . In one (1) embodiment, the wheel sets  34  are moved backwards between about 5 and 10 degrees. However, it is understood that the amount the wheels sets  34  are pivoted back depends on the position of the axle assembly  10  between the ends  100 A and  100 B of the radial stacker  100 . The shorter the distance between the axle assembly  10  and the off-load end  100 B of the radial stacker  100 , the smaller the pivot back angle.  
      To use the radial stacker  100  to move and stack material along an arcuate or radial path once the radial stacker  100  is in the operational mode with the wheel sets  34  in the extended, operational position, the conveyor belt  104  of the radial stacker  100  is activated and material is loaded on the infeed end  100 A of the radial stacker  100 . As the material is off-loaded at the off-load end  100 B of the radial stacker  100 , the wheels  36  of the wheel assemblies  20  and  50  of the axle assembly  10  can be rotated to move the back or off-load end  100 B of the radial stacker  100  which changes the off-load position. In one (1) embodiment, the motors  44  of the first wheel set  34  are activated to move the radial stacker  100 . In one (1) embodiment, only the motors  44  in one of the wheel sets  34  are activated while the wheels of the opposite wheel set are allowed to rotate freely. In another embodiment, where the wheel sets  34  have brakes  46 , the brakes  46  of the first wheel set  34  located in the direction of the desired movement are engaged. Therefore, to move the radial stacker  100  in a counterclockwise direction, the brakes  46  of the first wheel set  34  on the left side of the radial stacker  100  as viewed from the infeed end  100 A of the radial stacker  100  are engaged. Next the second piston cylinder  42  of the first wheel assembly  20  is extended to attempt to move the first wheel set  34  into the unextended position. As the second piston cylinder  42  applies a pushing force on the first end  30 A of the connector arm  30 , the brakes  46  prevent the wheels  36  from rotating which resists the movement of the first wheel set  34  to the unextended position. The friction between the wheels  36  and the ground surface may also prevent the wheels  36  from moving. Failure of the wheels  36  to move causes the connector arm  30  which is connected to the second piston cylinder  42  to pull the remainder of the radial stacker  100  in a direction toward the braked first wheel set  34 . The first wheel set  34  is moved into the unextended position by moving the radial stacker toward the first wheel set  34 . When the first wheel set  34  is in the unextended position, the brakes of the second wheel set are engaged and the brakes  46  of the first wheel set  34  are disengaged. The second piston cylinder  42  for the first wheel set  34  is retracted to move the first wheel set  34  back into the extended position. The brakes of the second wheel set prevent the radial stacker  100  from moving as the first wheel set  34  is moved to the extended position. In one (1) embodiment, to reposition the radial stacker  100 , the wheel sets  34  are rotated forward so that the axis of rotation C-C of the wheel sets  34  is perpendicular to the longitudinal axis B-B of the radial stacker  100 . The position of the axis of rotation of the wheel sets  34  enables the radial stacker  100  to be moved laterally.  
      It is intended that the foregoing description be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims.