Abstract:
An apparatus for picking up, stacking and bundling lumber, that comprises: a drive means, a conveyor assembly having a receiving bin and a conveyor, a stacking assembly operatively connected to the conveyor assembly, and having an unscrambling hopper, a row conveyor, a stacking bin and a bundling assembly a discharge platform, and a grapple assembly that picks up lumber pieces from the ground and deposits them into the receiving bin, and that also picks up bundles of lumber produced by the stacking assembly, for movement to a secondary location. The apparatus can be used on a variety of different terrains, including inclines and declines and can pick up lumber from a wide radius around the apparatus and from a number of ground conditions including rocky, muddy and wet ground.

Description:
FIELD 
       [0001]    The present invention relates to an all terrain apparatus for collecting and stacking lumber pieces. 
       BACKGROUND 
       [0002]    In laying pipe, such as in gas or oil pipeline, it s conventional that lengths of pipe are supported end to end on stacked lumber pieces known as “skids” so that the pipe lengths can be held at a required height to be supported and aligned end to end for welding of the lengths, prior to feeding of the completed welded length into a trench adjacent to the stacks. After the pipe lengths are welded into a continuous length, the pipe is lifted from the skids and deposited in a continuous action along its length into the trench. 
         [0003]    At some point, usually after the pipe has been laid into the trench, it is necessary to collect the lumber pieces from the skids and to transport them to a new site, preferably to be used again, for example at a further location along the pipeline. 
         [0004]    The lumber pieces, which are conventionally either four or five feet in length and six by four inches in cross section are lifted and handled manually for stacking onto a transport container. This manual process is expensive and time consuming, since it requires a gang of laborers working hard and commanding high wages. In many cases the stack has been disturbed, and the pieces are strewn about, or even compressed in the ground by the tracks of passing vehicles, making the work even more labor intensive. 
         [0005]    While this step is a relatively minor one in the process of laying the pipeline, it constitutes a significant expense and therefore provides a significant opportunity for a manufacturer of an effective machine which will carry out this step while eliminating or reducing the manual labor involved. 
         [0006]    In U.S. Pat. No. 5,934,861 issued Aug. 10, 1999, which corresponds to Canadian patent application no. 2,241,682 published February 1999, discloses an apparatus for picking up pieces of lumber and conveying them to a transport truck. Canadian patent application no. 2,315,046 published Feb. 3, 2002 discloses an apparatus for picking up, stacking and bundling pieces of lumber. 
         [0007]    Both of these prior art apparatuses are limited in application, in that they require smooth, flat and dry ground conditions in order to pick up lumber pieces from the ground. Further, they cannot pick up lumber pieces from a ground surface that is more than 30 cm above or below the tractor that is powering the apparatus. They are also limited in that the area in which lumber can be picked up is restricted to the width of the opening of the pick up section of the apparatus. 
       SUMMARY 
       [0008]    The present apparatus uses a grapple to pick up and deposit lumber pieces from the ground into a conveyor assembly, which cleans and orients the lumber for deposition into a stacking and bundling assembly. The bundled lumber that is prepared by the stacking and bundling assembly can be deposited to the ground, or it can be stored in a storage area on the apparatus itself, where it may be carried to a secondary location for transfer to another vehicle. The grapple may be used to move the bundles of lumber that are prepared by the stacking and bundling assembly, either to the ground or to the storage area on the apparatus. 
         [0009]    One advantage of the apparatus described herein, as compared to prior art apparatus disclosed in Canadian patent application no. 2,315,046, is that it does not have to be moving in a forward direction, in order to pick up lumber pieces from the ground. Therefore it may be used for stationary yard work. Another advantage is that the apparatus can pick up and bundle lumber from many different types of uneven ground surfaces (e.g., muddy, rocky, wet), or from water. Another advantage is that it may pick up lumber over a wide area surrounding the apparatus, for example in front of or on both sides of the apparatus, or on either side of the pipeline or the trench in which the pipeline has been laid. In one embodiment the apparatus comprises leveling means, so that it is able to function on inclines and declines. In one embodiment the apparatus can store bundled lumber for transport to a secondary location, avoiding the need to have a second vehicle pick up and transport the bundled lumber produced by the apparatus. 
         [0010]    In one aspect, the invention is an apparatus for picking up, stacking and bundling lumber, comprising:
       (a) a drive means,   (b) a conveyor assembly that comprises a receiving bin and a conveyor,   (c) a stacking assembly operatively connected to the conveyor assembly, and that comprises an unscrambling hopper, a row conveyor, a stacking bin and a bundling assembly,   (d) a discharge platform, and   (e) a grapple assembly sized to pick up lumber pieces and deposit the lumber pieces into the receiving bin.       
 
         [0016]    In one embodiment, the grapple assembly is further sized to pick up a bundle of lumber produced by the stacking assembly, for movement to a secondary location. In another embodiment, the drive means is a vehicle and the grapple assembly is mounted to the vehicle. In another embodiment the conveyor assembly, stacking assembly and discharge platform are on a trailer that is pulled by the vehicle. In another embodiment the grapple assembly is mounted to the trailer. In another embodiment, the apparatus further comprises a storage area. In yet another embodiment, the apparatus further comprises a means of raising and lowering the conveyor assembly. 
         [0017]    In another aspect, the invention is a method of picking up, stacking and bundling lumber, comprising:
       (a) providing an apparatus that comprises:
           (i) a conveyor assembly that comprises a receiving bin and a conveyor;   (ii) a stacking assembly operatively connected to the conveyor assembly, and that comprises an unscrambling hopper, a row conveyor, a stacking bin and a bundling assembly;   (iii) a discharge platform, and   (vi) a grapple assembly,   
           (b) picking up loose lumber with the grapple and depositing it into the receiving bin, and   (c) conveying the loose lumber along the conveyor to the stacking assembly, where the lumber is stacked and bundled into a bundle of lumber and deposited onto the discharge platform.       
 
         [0025]    The method may further comprise the step of picking up the bundle of lumber from the discharge platform with the grapple and transferring it to a secondary location, such as a storage area provided on the apparatus. 
         [0026]    In yet another aspect, the invention is an apparatus for picking up, stacking and bundling lumber, comprising:
       (a) a drive vehicle comprising a grapple assembly,   (b) a trailer pulled by the drive vehicle that comprises:
           (i) a conveyor assembly further comprising a receiving bin and a conveyor,   (ii) a stacking assembly operatively connected to the conveyor assembly, further comprising an unscrambling hopper, a row conveyor, a stacking bin and a bundling assembly, and   (iii) a discharge platform,   
           wherein the grapple assembly comprises a grapple that is sized to pick up lumber and a bundle of lumber,   and wherein the grapple assembly is sized to pick up lumber from a ground surface, to deposit said lumber into the receiving bin, and to pick up a bundle of lumber deposited onto the discharge platform.       
 
         [0034]    The apparatus may further comprise a storage area on the trailer, and the grapple assembly may further be sized to pick up a bundle of lumber from the discharge platform and deposit the bundle of lumber in the storage area. The apparatus may further comprise a mast assembly for raising and lowering the conveyor assembly. 
         [0035]    The apparatus may further comprise a means for adjusting the length of the unscrambling hopper or the stacking bin. The apparatus may further comprise a means for adjusting the width of the stacking bin. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0036]      FIG. 1  is a top plan view of one embodiment of the apparatus of the invention. 
           [0037]      FIG. 2  is a side elevation view of one embodiment of the apparatus of the invention. 
           [0038]      FIG. 3  is a side perspective view of one embodiment of the grapple. 
           [0039]      FIG. 4  is a side elevation view of one embodiment of the grapple. 
           [0040]      FIG. 5  is a side perspective view of one embodiment of the elevating chain assembly and row conveyor. 
           [0041]      FIG. 6  is a side elevation view of one embodiment of the row conveyor. 
           [0042]      FIG. 7  is a side perspective view of one embodiment of the unscrambling hopper and row conveyor. 
           [0043]      FIG. 8  is a sectional view taken along line I-I of the apparatus shown in  FIG. 1 . 
           [0044]      FIGS. 9A-E  is side perspective views of one embodiment of the stacking bin, bundling assembly and discharge platform.  FIGS. 9A-D  demonstrates the process of moving the stack through the bundling assembly to the discharge platform.  FIG. 9E  shows various features of the stacking bin. 
           [0045]      FIGS. 10A-C  is side elevation views of an embodiment of the apparatus of this invention traveling up a hill with a 27 degree incline (A), on relatively level ground (B) and down a hill with a 27 degree decline. 
           [0046]      FIG. 11A  is an end elevation view of an embodiment of the apparatus of the invention showing the position of the mast assembly and conveyor assembly relative to the trailer, when the apparatus is on an incline (C), level ground (B) or decline (A).  FIG. 11B  is a side elevation view of an embodiment of the apparatus of the invention showing the position of the conveyor assembly relative to the stacking assembly, when the apparatus is on an incline (C), level ground (B) or decline (A). 
           [0047]      FIG. 12  is an end elevation view of an embodiment of the apparatus of the invention demonstrating how the mast assembly is positioned, after removal of the conveyor assembly, for transport. 
           [0048]      FIG. 13  is a side elevation view of the bundling assembly and discharge platform. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0049]    Reference will now be made to  FIGS. 1-13 , which show exemplary embodiments of the apparatus of the invention. 
         [0050]    The apparatus  1 , as shown in  FIG. 1 and 2 , comprises a drive means  10 , a grapple assembly generally indicated at  14 , a conveyor assembly generally indicated at  18 , a stacking assembly generally indicated at  20 , a discharge platform  22  and optionally, a storage area  24 . The grapple assembly  14  comprises a working arm  26 , a grapple  30 , and an optional extension arm  28 . The conveyor assembly  18  comprises a receiving bin  32  and a conveyor  34 . The stacking assembly  20  comprises an unscrambling hopper  36 , a row conveyor  38 , a stacking bin  40  and a bundling assembly  42 . 
         [0051]    The apparatus is moved by drive means  10 , such as a vehicle (i.e., excavator), which may be operated by a driver who may sit in a cab  12 . The driver may also operate grapple assembly  14  and conveyor assembly  18 . The apparatus is used to pick up, stack and bundle, lumber or timber. In one embodiment the lumber has been used to make skids for supporting a pipeline, but other types of lumber, such as that used in railway operations, could be picked up by this apparatus. A rear operator standing near the stacking assembly generally at position  43 , controls the stacking operation and various other aspects of the stacking and bundling process, as will be described in more detail below. 
         [0052]    In one embodiment, shown in  FIGS. 1 and 2 , conveyor assembly  18 , stacking assembly  20 , discharge platform  22  and storage area  24  may be mounted to a trailer or frame  16  that may be attached to and pulled by drive means  10 . In another embodiment, drive means  10 , conveyor assembly  18 , stacking assembly  20 , discharge platform  22  and optional storage area  24  may be of unitary construction (i.e., the drive means may not be a separate entity from the remainder of the apparatus). 
         [0053]    The grapple assembly  14  comprises working arm  26  and grapple  30 , and optionally an extension arm  28 , the movement of which may be controlled by hydraulic cylinders, as is known in the art. Working arm  26  may be pivotally mounted to drive means  10  in such a manner that it may be capable of rotating vertically through a range of 360 degrees. In an alternative embodiment, working arm  26  may be mounted to trailer  16  in such a manner that it may be capable of rotating vertically through a range of 360 degrees. The driver is able to view grapple  30  in all of its orientations, in order to control the picking up of lumber pieces  44 . 
         [0054]    In one embodiment, shown in  FIG. 2 , working arm  26  may be mounted onto cab  12 , which may be pivotally mounted to drive means  10 . Cab  12  and therefore working arm  26 , may rotate vertically around axis  27  through a range of 360 degrees rotation. Extension arm  28  may be pivotally mounted and extend between working arm  26  and grapple  30 . Grapple  30  may be capable of rotating vertically around axis  31  through a range of 360 degrees and therefore may be rotated fully to pick up lumber pieces  44 , regardless of the orientation of the lumber on the ground. In another embodiment, grapple  30  may be attached to working arm  26  at end  29 , and may be able to rotate vertically through a range of 360 degrees. 
         [0055]    Grapple  30  may be used to grasp one, two or several pieces of lumber  44 . As shown in  FIGS. 3 and 4 , grapple  30  has two grapple arms  48 , each of which may be curved. The curvature causes loose lumber pieces to slide down into the grasp of the grapple as the grapple is being closed, to be carried therein. The grapple arms may also pivot upwards towards top section  50 , to hold the lumber pieces between the arms  48 , or between the top section  50  and grapple arms  48 . 
         [0056]    Grapple  30  may also be used to pick up a bundle  46  of lumber, which may in some embodiments be rectangular (e.g., square) in cross section. To this end, the curvature of each of the grapple arms  48  may taper gently from the tip  52  to pivot point  54 , where there may then be a sharp turn towards top section  50 . Top section  50  may be sized to accommodate the full width of a side of the bundle of lumber that is to be picked up, and may be relatively flat. This enables top section  50  of grapple  30  to engage the full side of the bundle  46  of lumber. The grapple arms  48  may then close around the bundle to squeeze the bundle from the bottom and push it up against top section  50 . By gripping the bundle  46  in this way, the corner edges of the bundle and the sides of the bundle may not be distorted, and the shape of the bundle of lumber may be maintained. Grapple  30  may be opened and closed using a hydraulic cylinder assembly, as is known in the art. 
         [0057]    The conveyor assembly  18  receives the lumber pieces from the grapple and transports the pieces to unscrambling hopper  36 . The conveyor assembly comprises receiving bin  32  to receive the lumber pieces that are deposited therein by grapple  30  and conveyor  34 , which transports the lumber pieces to unscrambling hopper  36 , as best seen in  FIG. 1 . In one embodiment, receiving bin  32  may comprise a series of rollers  56  along its bottom. These rollers may each comprise a shaft and a plurality of disks—i.e., they may be “knobbed”. Knobbed rollers  56  remove and filter mud and other debris from the lumber pieces. Conveyor  34  conveys lumber pieces from receiving bin  32  to unscrambling hopper  36 . Conveyor  34  may also function to orient the lumber pieces, because it may be narrower in width than the length of the lumber pieces being conveyed, and therefore the lumber pieces would generally be oriented longitudinal of the conveyor  34  before deposition into unscrambling hopper  36 . In one embodiment conveyor  34  may comprise a conveyor belt  58  mounted on a plurality of rollers (not shown) so that an upper run of the belt carries the lumber pieces towards unscrambling hopper  36 . In another embodiment conveyor  34  may comprise a series of rollers, in addition to the rollers  56  along the bottom of bin  32 , that transport lumber pieces from bin  32  into hopper  36 . In yet another embodiment, these additional rollers may be knobbed, for further cleaning of the lumber pieces. Conveyor  34  may be a part of, or integral to, bin  32 . 
         [0058]    The lumber pieces are discharged from conveyor  34  into unscrambling hopper  36 , which is the first component of stacking assembly  20 . Stacking assembly  20  functions to assemble the loose lumber pieces into a stack of predetermined shape and size, and to bundle the pieces of that stack securely together. Stacking assembly  20  need not be mounted in a subframe. 
         [0059]    Unscrambling hopper  36  functions to receive the scrambled lumber pieces from conveyor  34 , and to orient them all into the same direction, for formation of the stack. Unscrambling hopper  36  comprises a front wall  60 , a back wall  62  and two side walls  64  and  66  that form at their base an apex  68  longitudinal of unscrambling hopper  36  and thus longitudinal of conveyor  34 . Side wall  64  may be inclined and may comprise an elevating chain assembly  70  that may be made of three parts, a center chain  72  and two side chains  74 . 
         [0060]    At apex  68  may be a roller assembly  76  comprising a plurality of unscrambling rollers  78  that may be spaced apart to permit debris to fall therebetween onto the ground surface. Unscrambling rollers  78  may be oriented at approximately right angles to the direction from which the lumber is received (i.e., approximately parallel to the front and back walls  60  and  62 ), and they may be sloped so that the ends closest to side wall  64  may be lower than the ends closest to side wall  66 . Rollers  78  rotate in unison and in the same direction, which rotation may be controlled by the rear operator, using a variable hydraulic valve. In a preferred embodiment, rollers  78  rotate in a direction that causes the lumber pieces to be moved towards back wall  62 . The rotation and sloping of the unscrambling rollers  78  displaces lumber pieces  44  towards elevating chain assembly  70 , and in a preferred embodiment towards back wall  62 . Spiral flighting  80  on one or more of the unscrambling rollers  78  may also be used, to facilitate the movement of lumber pieces  44  towards elevating chain assembly  70 . 
         [0061]    The roller assembly  76  may be lowered by the driver or rear operator, for example by unlatching the assembly and activating one or more hydraulic cylinders, to lower the roller assembly.  FIG. 8  shows the roller assembly  76  at lowered position  79  (which is a partially opened position). This will permit, for example, the removal of large rocks or debris from unscrambling hopper  36 . 
         [0062]    Front wall  60  may further comprise an additional panel  82  that enables the driver or rear operator to make adjustments to vary the length of the apex  68 , as shown in  FIG. 2 . The top edge of panel  82  may be attached to front wall  60 , for example to a slotted track, to permit the top edge to slide vertically when the bottom edge of panel  82  is moved towards and away from back wall  62 . Arrow  83  in  FIG. 2  shows how the bottom edge of panel  82  may be moved towards and away from front wall  60 . At the bottom edge of panel  82 , tubular supports may be used to secure the bottom edge in a selected position. This panel feature facilitates the use of unscrambling hopper  36  with lumber pieces of varying lengths—for example 4 feet or 5 feet in length. 
         [0063]    Disposed inside back wall  62  may be an adjustable panel  84  that may be moved towards and away from front wall  60 , as seen in  FIG. 2 . The position of panel  84  may be determined by adjustment, in increments, of telescoping tubular supports  86  mounted to stationary back wall  62 . This permits the driver or rear operator to adjust the length of apex  68  or hopper  36 , to facilitate use with lumber pieces of varying lengths—for example 4 feet or 5 feet in length. 
         [0064]    Supports  86  may be independently adjustable. Therefore, panel  84  may be adjusted to tilt from top to bottom, so that the top edge of the panel may be closer to front wall  60  than the bottom edge of the panel. By tilting panel  84  in this way the lumber pieces, as they are raised upwards by elevating chain assembly  70 , may be forced flush at one end for bundling. When combined with a preferred embodiment, mentioned above, in which rollers  78  rotate in a direction that causes the lumber pieces to be moved towards back wall  62 , this feature eliminates the need for an end alignment belt to align the lumber pieces in the stack. 
         [0065]    Panel  84  may also be adjusted to tilt from side to side, so that one side edge may be closer to front wall  60  than the other side edge, more specifically, so that the edge running along side wall  64  may be further from front wall  60  than the edge running along side wall  66 . By tilting panel  84  in this way, lumber pieces  44  may move with less friction towards elevating chain assembly  70 , located on side wall  64 . 
         [0066]    The top portion of adjustable panel  84 , or of back wall  62 , may comprise an additional plate  88  that may be attached to panel  84  or to back wall  62 , at the bottom edge, for example with a hinge or by a slotted track. Thus, the top edge of plate  88  may be moved toward and away from back wall  62 . The top edge of plate  88  may be secured by a horizontal sliding and locking pin assembly that inserts into spaced vertical slots  67  on wall  66 . Arrow  89  in  FIG. 2  shows how the top edge of plate  88  may be moved towards and away from back wall  86 . When plate  88  is in a lowered position, as shown in  FIG. 2 , the alignment of lumber pieces onto elevating chain assembly  70  may be assisted by causing a piece of lumber that may be vertically oriented at the back wall  62 , when it contacts plate  88 , to be forced to fall back into the unscrambling hopper  36  in a horizontal orientation. 
         [0067]    Elevating chain assembly  70  comprises, in this embodiment, center chain  72  and two side chains  74 , one on either side of the center chain  72 . A plurality of substantially horizontal abutment bars  90  project outwardly, in order to engage lumber pieces  44 . The elevating chain assembly and abutment bars preferably extend across the entire width of side wall  64  rather than only part of side wall  64  as known in the prior art, and therefore debris build up in the bottom of unscrambling hopper  36  may be avoided. The abutment bars also facilitate unscrambling of lumber pieces as they are received in unscrambling hopper  36 , as lumber pieces that become positioned vertically in the unscrambling bin may be dislodged by the abutment bars. As is apparent, elevating chain assembly  70  may also be made of one or two elevating chains, or more than three elevating chains. The same advantages (i.e., avoiding build up of debris and dislodging lumber pieces) can be achieved using any assembly of elevating chains wherein the abutment bars extend substantially from side to side of wall  64 . 
         [0068]    Elevating chain assembly drive sprockets  92  may be mounted on an upper shaft  94  and idler sprockets  96  may be mounted on shaft  98 , with chains  100  carried thereon. As shafts  94  and  98  rotate, lumber pieces in unscrambling hopper  36  are engaged by abutment bars  90 , lifted upwards along inclined side wall  64  over the top edge of the side wall and deposited onto row conveyor  38 . 
         [0069]    Row conveyor  38  functions to assemble a row of lumber pieces  44  and to transfer that row into stacking bin  40 , to form a stack of lumber pieces. Row conveyor  38  may comprise idler sprockets  102 , drive sprockets  104  and chains  106 . Idler sprockets  102  may be mounted on upper shaft  94 . The use of upper shaft  94  with both elevating chain assembly drive sprockets  92  and idler sprockets  102  provides for a smooth transition of lumber pieces  44  from the elevating chain assembly  70  to the row conveyor  38 . The lumber pieces may be deposited onto chains  106 , and may be moved on chains  106  towards stacking bin  40 . Row conveyor  38  may additionally comprise an adjustable alignment fence  108 , to help ensure that the ends of the lumber pieces are flush with one another for bundling. 
         [0070]    Lumber pieces  44  are fed up the elevating chain assembly  70  generally side by side onto conveyor chains  106 . If more than one lumber piece is carried on any particular abutment bar  90 , the pieces may end up on top of one another on the row conveyor and this problem may be overcome manually by the rear operator standing on the apparatus near the row conveyor  38 , generally at area  43 , to ensure that the stacking process proceeds effectively. 
         [0071]    Lumber pieces  44  may be fed along row conveyor  38  over top of a pair of lifting arms  110 , which may normally be positioned below the level of chains  106  (in “home position”), so that lumber pieces  44  will clear rear dog  115  as they move on the row conveyor. The lumber pieces progress towards stacking bin  40  until they abut stops  112 , which halt the forward movement of the lumber pieces. The pieces that follow back up against the previously stopped pieces to form a row of lumber pieces arranged side-by-side and extending back towards unscrambling hopper  36 . When a lumber piece is positioned and stopped overtop of sensor  114 , the approximate location of which is shown in  FIG. 6 , lifting arms  110  may be lifted up by an actuating mechanism  111 , activated for example by a hydraulic cylinder, that simultaneously lowers stops  112 . The lifting arms  110  lift up the row of lumber and rear dog  115  on each of the arms engages the rearmost lumber piece of the accumulated row. The row is carried forward on a carriage system  116  driven by chains  118 , to bundle elevator in stacking bin  40 , which may comprise horizontal spaced supports  122  mounted onto a carriage  123 , that may be an independent roller assembly that moves vertically in a track (not shown). When lifting arms  110  are extended over the horizontal spaced supports, actuating mechanism  111  retracts, thus lowering arms  110  to home position and simultaneously raising stops  112 . The lumber pieces abut end  120  ( FIG. 5 ), as the lifting arms  110  being to retract towards hopper  36 , and may thus be deposited onto supports  122 . 
         [0072]    The bundle elevator may already have one or more rows of lumber loaded thereon, and/or the rear operator may have manually adjusted a tier of lumber in order to later assist with the handling and transfer of bundle  46 , for example with a forklift.  FIGS. 9A-D  shows a stack of lumber in which lumber in the second from bottom tier has been reoriented manually to facilitate future movement and storage of bundle  46 . The stacking of additional rows of lumber continues until horizontal spaced supports  122  are lowered to a point where they are below stacking rollers  124 , thus leaving the stack of lumber sitting on the stacking rollers  124  at the bottom of the stacking bin  40 . The rollers  124  may then be driven by a chain  125 , connected across chain wheels  119 , so as to forward the stack into bundling assembly  42 . 
         [0073]    Stacking bin  40  assembles the rows of lumber pieces into a stack and transmits that stack to bundling assembly  42 . The stacking bin has a front  126 , a back  128  and sides  130  and  132 . Rollers  134  extend vertically on the front of the stacking bin. In one embodiment, rollers  134  extend from the ends of rollers  124  and may be driven by a gear assembly from the end of rollers  124 . These rollers reduce the probability that the stack of lumber pieces will snag the stacking bin  40 , as the bundle moves horizontally into bundling assembly  42 . 
         [0074]    Several other features of stacking bin  40  represent improvements over the stacking bin disclosed in CA patent application no. 2,315,046. Back  128  may comprise a plate  127  that may be adjustable to move substantially horizontally towards and away from front  126 , to accommodate lumber of varying widths. For example, a standard width of lumber is six inches, however this width may be more or less than six inches. If plate  127  does not fit snugly up against the lumber stack, the outer lumber pieces  44  may fall into the gap between the wall and the stack, and therefore distort the shape of the stack before it moves horizontally into bundling assembly  42 . The position of plate  127  may be determined by adjustment, in increments, for example by a threaded rod inside tubular supports  129  mounted to the frame of stacking bin  40 . 
         [0075]    Plate  127  may also be hinged at the bottom to allow the wall to fold inwards and downwards, which may be accomplished, for example, with hydraulic cylinders. This feature may be used during transport of the apparatus, as the stacking bin and bundling assembly may be rotated 180 degrees for transport, to rest over top of row conveyor  38 . 
         [0076]    Side  130  may comprise a plate  136  that may be adjustable to move towards and away from side  130 , in order that the stacking bin  40  may accommodate lumber pieces of varying length, such as 4 feet or 5 feet. In one embodiment plate  136  may be adjusted by six inches. Adjustment of plate  136  may be accomplished by a wheel and pulley mechanism  138 , as shown in  FIG. 9 . 
         [0077]    Bundling assembly  42  comprises a substantially rectangular frame  140  sized to receive the stack of lumber therein, even in the event that the stack may be slightly loose or expanded in dimension by distorted or slightly twisted pieces. The bottom rail  142  of frame  140  may comprise a horizontal drive roller  144  disposed in the frame, to reduce the probability that the bottom row of lumber in the stack will become snagged by bottom rail  142  as it is advanced through the opening in the frame, and thereby hinder bundling of the stack. 
         [0078]    Bundling of the stack occurs essentially as described in CA patent application no. 2,315,046, which is incorporated by reference herein, and which is best shown in  FIGS. 8 and 9 . In addition to bottom rail  142 , frame  140  comprises a top rail  145  and two side rails  146  and  148 . A first clamping arm  147  may be disposed substantially parallel to a first rail, preferably retracted into a slot of the rail. The first clamping arm is preferably retracted into top rail  145 . A second clamping arm  149  may be disposed substantially parallel to another rail that is substantially perpendicular to the first rail, preferably retracted into a slot in the rail. The second clamping arm is preferably retracted into side rail  146 . Each of these clamping arms may be actuated with a pair of hydraulic cylinders  150  or  152  (see  FIG. 8 ), into engagement with a surface of the stack of lumber, to thereby squeeze the lumber pieces within the stack so that they may be pressed together to eliminate spaces between the pieces and the ensure that they are fully aligned and in contact. 
         [0079]    With the stack thus clamped, a length of strapping material  154  may be used to hold the lumber pieces in the stack securely together. Strapping material  154  may be carried around the stack by a chain  156 , which extends around four sprockets  158  each mounted at a corner of frame  140 . One of the sprockets may be driven and the others may be idlers, so that the chain can be rotated around the frame so as to complete a single loop around the frame. The chain  156  and sprockets  158  may be mounted on either the front or rear face of frame  140 , so that they are alongside the frame and do not interfere with the movement of the stack through the frame  140 . The chain carries, at one end, a gripping member (not shown) around which an end of strapping material  154  can be engaged so that the end may be carried with the chain as it moves around the frame, thus carrying the end completely around the stack to a position where it may be crimped manually with another end of the strapping material. The two ends of the loop of strapping material  154  may be crimped by a manually operable strapping system known in the art. For example, a crimping head that acts to tighten the loop and simultaneously crimp or lock the two ends of the loop together so the strapping is maintained fixed around the stack, may be used. 
         [0080]    Clamping arms may then be released and the bundle  46  may then be advanced by stacking rollers  124  and/or discharge platform  22 , and positioned to apply one more strap thereabout. When the desired number of straps is applied, the stacking rollers  124  and/or discharge platform  22 , may be activated to move the stack from its position in bundling assembly  42  onto discharge platform  22 . 
         [0081]    Discharge platform  22  is an area where bundle  46  may be deposited, so that it can be picked up by grapple assembly  14 . Alternatively, discharge platform may be designed to deposit bundle  46  directly onto the ground. In one embodiment, the discharge platform includes a conveyor belt  160  and rollers  161   a  and  161   b  to advance bundle  46  out of the bundling assembly  42  on an upper run of the belt. Grapple assembly  14  may then pick up bundle  46  and deposit it in storage area  24 , onto another vehicle nearby or onto the ground. 
         [0082]    Discharge platform  22  may be fixed to trailer  16  with shear bolts  135  which may be attached to support frame  137  that rests on a bracing member  139 , as shown in  FIG. 13 . The shear bolt is a safety mechanism to protect the stacking assembly from damage that might result from operator error when attempting to lift bundle  46  with grapple assembly  14 . If, for example, the entire weight of the grapple is placed onto platform  22 , shear bolts  135  will break and platform  22  will pivot at point  141 , and swing downwards. 
         [0083]    Storage area  24  may be sized to accommodate several bundles  46  of lumber, beside one another and/or stacked on top of one another. Bundles of lumber may be deposited in storage area  24  and transported to a second location, avoiding the need for a second vehicle, such as a Skidsteer, to follow the apparatus and pick up the bundles. In one embodiment the apparatus can carry 10 bundles of lumber. The bundles of lumber thus stored may be picked up by the grapple assembly  30  and moved to a secondary location, such as a storage yard or a second vehicle. 
         [0084]    The apparatus of the present invention may be used on terrain that is not level, as indicated in  FIG. 10A-C . Therefore, in some embodiments, also provided is a means of maintaining stacking assembly  20  level which may be coupled with a means of leveling conveyor assembly  18 , in response to varying terrains, so that it will efficiently deposit lumber pieces into unscrambling hopper  36 . This feature, in addition to the use of a grapple, provides even greater flexibility with regard to terrain, than the prior art device disclosed in Canadian patent application no. 2,315,046, or the use of a grapple alone.  FIG. 10  demonstrates the relative movement of conveyor assembly  18  and stacking assembly  20 , when an embodiment of the apparatus comprising both a means for leveling the conveyor assembly  18  and stacking assembly  20 , is proceeding up a hill with an incline of 27 degrees ( 10 A), on a level surface ( 10 B), and down a hill with a decline of 27 degrees ( 10 C). As noted, stacking assembly  20  remains relatively level in all situations. This may be accomplished by pivoting stacking assembly  20  about pivot point  163  by actuating hydraulic cylinders  162 . As stacking assembly  20  pivots about  163 , the end of conveyor assembly  18  may also pivot about pivot point  165 . 
         [0085]    The apparatus may also comprise a mast assembly  164 , to raise and lower the conveyor assembly  18 , to accommodate for the slope of the land on which the apparatus is being used. Therefore, conveyor assembly  18  may be moved up or down along mast assembly  164 , which may comprise an inner mast  166  and an outer mast  168 , each of which may comprise a hydraulic cylinder disposed therein to provide means of moving the mast vertically.  FIGS. 11A  and B shows the position of outer mast  168  and inner mast  166  at three different positions or heights, A, B and C, of conveyor assembly  18 , corresponding to  FIG. 10C ,  FIG. 10B  and  FIG. 10A , respectively. 
         [0086]    Inner mast  166  may be mounted relatively perpendicular to the chassis of the trailer  16 , as shown in  FIG. 11A , and may be pivotally connected to outer mast  168  at pivot point  170 . Conveyor assembly  18  may be attached to outer mast  168  at pivot point  172 , and moves up and down with outer mast  168 . Inner mast  166  telescopes upwardly to achieve position A in  FIG. 10C . Outer mast  168  pivots about point  170  on inner mast  166 , as conveyor assembly  18  moves up and down pivoting about point  172 . The angular displacement of outer mast  168  relative to inner mast  166  can best be seen in  FIG. 11B  at arrows  174 . As the mast assembly  164  is raised and lowered, the other end of conveyor assembly  18  may also pivot about pivot point  165 . 
         [0087]    In preparation for transport of the apparatus, conveyor assembly  18  may be removed from mast  168 , and mast assembly  164  may be lowered into a prone position for transport, by pivoting about point  173 , in the direction of arrow  175 , as shown in  FIG. 12 . Additionally, unscrambling hopper  36  may be pivoted about shaft  94  by 180 degrees, to rest on top of row conveyor  38 . At the other end of row conveyor  38 , plate  127  of stacking bin  40  may be lowered onto stacking rollers  124 , and discharge platform  22  may be pivoted upwards by about 90 degrees about the shaft  169  of roller  161   a,  and latched to bundling assembly  42  (see  FIG. 13 ). The stacking bin  40 , bundling assembly  42  and discharge platform may then be rotated 180 degrees about axis  176  (see  FIG. 9E ), to rest on top of the unscrambling hopper  38 . The stacking bin and attached bundling assembly/discharge platform may be lifted and flipped over by using grapple assembly  14  to grasp a sling that may be connected to a lifting lug  178 , shown in  FIG. 13 . A similar lug/sling assembly may be used to lift and flip over unscrambling hopper  36 . In this manner, the width of the apparatus may be reduced to facilitate transport. 
         [0088]    The driver of drive means  10 , therefore, preferably controls the picking up and feeding of lumber pieces  44  into conveyor assembly  18 , the conveyor assembly  18 , and the removal of bundle  46  from discharge platform  22 . The rear operator standing near the stacking assembly  20  preferably controls the stacking action by controlling the feeding of the row of lumber pieces, ensuring that the pieces are properly oriented and carried onto the bundle elevator, and controlling the feeding of the bundling through the bundling assembly and bundling thereof. 
         [0089]    Having thus described apparatus  1  of the present invention, a method of picking up and bundling lumber pieces  44 , will now be described. A driver, who preferably also controls the drive means  10  of the apparatus, operates grapple assembly  14 , to pick up one or more pieces of lumber  44  from the ground. The lumber piece or pieces are deposited into receiving bin  32  by positioning grapple  30  above the receiving bin, and opening grapple arms  48  to drop the lumber pieces into the bin. Rollers  56  turn, to move the lumber pieces towards conveyor  34 , which transports the lumber pieces into unscrambling hopper  36 . In unscrambling hopper  36  the elevating chain assembly sequentially lifts the lumber pieces  44  up and deposits them one at a time onto row conveyor  38 . On row conveyor  38  the lumber pieces  44  are assembled into rows, and the rows are assembled one on top of another into a stack of lumber, in stacking bin  40 . The stack may then be moved into bundling assembly  42 , where it is bundled into a bundle  46 , and deposited onto discharge platform  22 . A rear operator, preferably standing near the stacking assembly ensures that the stacking and bundling process proceeds smoothly. 
         [0090]    Bundle  46  may then be picked up by grapple assembly  14  and deposited in storage area  24 , onto a waiting vehicle, or onto the ground. Alternatively, the discharge platform  22  may deposit the bundle directly onto the ground. 
         [0091]    While the apparatus has been described in conjunction with the disclosed embodiments, it will be understood that the apparatus is not intended to be limited to these embodiments. On the contrary, the apparatus is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Various modifications will remain readily apparent to those skilled in the art.