Patent Publication Number: US-8527087-B1

Title: Dunnage placer

Description:
TECHNICAL FIELD 
     The disclosures provided herein relate to dunnage placing, and more specifically, to placing dunnage onto stacks of material. 
     BACKGROUND 
     Dunnage is widely used in many industries and in many applications. In many instances, dunnage is used to provide gaps or spaces in groups of stacked items. More specifically, dunnage is often used to provide a space or gap in order to allow the tines of a forklift or other material handing device to move a group of items that make up a stack. For example, consider a stacked group of items that is to be carried by a forklift and then set on a floor. It is often desirable to position several pieces of dunnage on the floor, and then to set the items on the dunnage. In this way, the dunnage provides a space or gap between the floor and the items so that the tines of the forklift can be easily removed from beneath the items after they are set in place on the dunnage. Similarly, the gap or space between the floor and the items allows the items to be more easily picked up with the forklift. 
     Dunnage is often employed in this manner in the lumber industry. For example, in many modern sawmills, and other types of lumber production and/or processing facilities, high-speed automatic lumber stackers or stack formers are used. These automatic stackers collect lumber pieces or boards from a production line and position or arrange the collected pieces into organized stack units. Often, the stacker is setup to form stack units of a given size and/or weight. The given stack unit size or weight can be determined according to one or more various factors. These factors can include, for example, the handling capacity of equipment that may be used to move or transport the stack units, and/or the handling capacity of equipment that may be used for additional processing of the stack units. For example, a common practice in the lumber industry is to employ a forklift to pick up the stack units as they emerge from the automatic stacker. Thus, the stack units must be of a size and/or weight that does not exceed the capacity of the forklift. 
     Typically, as stack units emerge from an automatic stacker, they are picked up by a forklift and then arranged one-on-top-of-another to facilitate efficient use of storage space or processing space. Dunnage pieces are often placed onto stack units as they emerge from the automatic stacker. More specifically, dunnage pieces are placed onto the stack units upon which other stack units will be placed. In many instances, a stockpile of dunnage is maintained near the output location of the automatic stacker. At the time a given stack unit is picked up by a forklift from the automatic stacker, the forklift driver will know whether dunnage is required to be placed on the given stack unit. If dunnage is required, it can be manually picked from the dunnage stockpile, and then placed onto the top of the stack unit that is to be picked up. Often, this manual picking and placement of the dunnage is done by the forklift driver. After the dunnage is placed on top of the stack unit, the forklift carries the stack unit to its destination with the dunnage in place on the top of the stack unit. 
     The identification of problems, deficiencies, potential or actual benefits or advantages described above is not admitted to be prior art. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Preferred forms, configurations, embodiments and/or diagrams relating to and helping to describe preferred aspects and versions of the inventions provided for herein are explained and characterized herein, often with reference to the accompanying drawings. The drawings, and all features shown therein, also serve as part of the disclosure of the inventions encompassed within the current document, whether described in text or merely by graphical disclosure alone. Such drawings are briefly described below. 
         FIG. 1  is an isometric view in which a stack unit is depicted. 
         FIG. 2  is simplified side elevation view in which an apparatus is depicted according to at least one embodiment of the present disclosure. 
         FIG. 3  is a simplified side elevation view in which a magazine of the apparatus of  FIG. 2  is depicted in isolation. 
         FIG. 4  is another simplified side elevation view of the magazine depicted in  FIG. 3 . 
         FIG. 5  is a simplified side elevation view in which a carriage of the apparatus of  FIG. 2  is depicted in isolation. 
         FIG. 6  is another simplified side elevation view of the carriage depicted in  FIG. 5 . 
         FIG. 7  is the first in a series of four simplified side elevation views in which operation of the carriage is depicted. 
         FIG. 8  is the second of the series of views of which  FIG. 7  is the first. 
         FIG. 9  is the third of the series of views of which  FIG. 7  is the first. 
         FIG. 10  is the fourth of the series of views of which  FIG. 7  is the first. 
         FIG. 11  is a schematic view in which is depicted the control system of the apparatus shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     The readers of this document should understand that the embodiments described herein may rely on terminology used in any section of this document and other terms readily apparent from the drawings and the language common therefor as may be known in a particular art, and such as known or indicated and provided by dictionaries. Dictionaries were used in the preparation of this document. Widely known and used in the preparation hereof are Webster&#39;s Third New International Dictionary (© 1993), The Oxford English Dictionary (Second Edition, © 1989), The New Century Dictionary (© 2001-2005), and the online dictionary, www.merriam-webster.com., all of which are hereby referenced for interpretation of terms used herein and for application and use of words defined in such references to more adequately or aptly describe various features, aspects and concepts shown or otherwise described herein using more appropriate words having meanings applicable to such features, aspects and concepts which are depicted or otherwise disclosed herein. 
     This document is premised upon using one or more terms with one embodiment that may also apply to other embodiments for similar structures, functions, features and aspects of the inventions. Wording used in the claims is also descriptive of the inventions, and the text and meaning of the claims and abstract are hereby incorporated by reference into the description in their entirety as originally filed. Terminology used with one, some or all embodiments may be used for describing and defining the technology and exclusive rights associated herewith. 
     The readers of this document should further understand that the embodiments described herein may rely on terminology and features used in any suitable section or other embodiments shown in this document and other terms readily apparent from the drawings and language common or proper therefor. This document is premised upon using one or more terms or features shown in one embodiment that may also apply to or be combined with other embodiments for similar structures, functions, features and aspects of the inventions and provide additional embodiments of the inventions. 
     The invention(s) provided for by this disclosure may include a number of different specific configurations, embodiments, and/or variations, some or all having different advantages or effects relative to features, operation and production. 
     Features shown on some of the illustrated and/or described versions may also be used on other embodiments if aspects of construction and use do not prevent such added configurations from being implemented according to this disclosure. 
     With reference now to the attached drawings,  FIG. 1  is an isometric view in which a stack unit  10  is depicted according to at least one embodiment of the present disclosure. The stack unit  10  has a first end  11  and an opposite second end  12 . The stack unit  10  is made up of individual stacked items  15 . The stacked items  15  can have at least one of a number of possible forms. By way of example, the stacked items  15  can be in the form of elongated elements such as beams, boards, posts or the like. The stacked items  15  can be one or more of a number of materials such as, but not limited to, wood, metal, polymer and composite material. According to one or more embodiments of the present disclosure, the stacked items  15  are newly manufactured bulk products such as lumber, for example, and the stack unit  10  is a product packaging unit and/or a product processing unit. As is seen from a study of  FIG. 1 , the exemplary stacked items  15  are arranged in a plurality of rows and columns to form an array. It is to be understood that the stack unit  10  can be alternatively formed from a single column of sheets or panels according to at least one alternative embodiment of the present disclosure. By way of example only, such sheets or panels can be in the form of wood products such as, but not limited to, plywood, fiberboard, strandboard, waferboard, and sheetrock. 
     With continued reference to  FIG. 1 , a plurality of dunnage pieces  20  are supported on top of the stack unit  10 . The dunnage pieces  20  can be supported on the top of the stack unit  10  in a substantially transverse orientation relative to the individual stacked items  11 , as shown. The exemplary dunnage pieces  20  are placed on the stack unit  10  so as to have a longitudinal orientation that is substantially perpendicular to the longitudinal orientation of the stacked items  11 . As is depicted, a dunnage piece  20  is positioned proximate the first end  11  of the stack unit  10 , while another piece is positioned proximate the second end  12  of the stack unit, and yet another dunnage piece is positioned intermediate the first and second ends of the stack unit. 
     The dunnage pieces  20  can be formed from a number of suitable materials. For example, the dunnage pieces  20  can be substantially in the form of sawn lumber. According to one or more embodiments of the present disclosure, each of the dunnage pieces  20  has a substantially square cross sectional shape, as depicted. For example, each of the dunnage pieces  20  can be a standard rough-cut four-by-four (4×4) wood board or timber. It is to be understood that the dunnage pieces  20  can contain and/or can be made from materials other than wood. The dunnage pieces  20  are of a suitable length and generally extend across the entire width of the stack unit  10 , as depicted. The dunnage pieces  20  are placed onto the stack unit by apparatus and methods described hereinbelow according to one or more embodiments of the present disclosure. 
     Turning now to  FIG. 2 , a side elevation view depicts an apparatus  100  according to at least one embodiment of the present disclosure. For purposes of clarity, the apparatus of  FIG. 2  is depicted in extremely simplified form, and certain features, components and/or portions of components not essential to the understanding of the description provided herein have been omitted. The apparatus  100  is adapted to place dunnage pieces  20  onto stack units  10 . The dunnage pieces  20  used in conjunction with operation of the exemplary apparatus  100  are all substantially identical to each other in size and shape. The apparatus  100  can be adapted to operate using dunnage pieces  20  of a particular size and/or shape. According to at least one embodiment of the present disclosure, the apparatus  100  is adapted to be adjustable so as to be set up to operate using dunnage pieces  20  of a given size and/or shape. According to at least one embodiment of the present disclosure, the dunnage pieces  20  are reused until they become worn beyond acceptable limits from normal use. 
     The apparatus  100  includes a support frame or chassis  110 . The chassis  110  is adapted to act as a substantially rigid structural support for other components of the apparatus  100 . The chassis  110  can be constructed, for example, from structural steel members such as, for example, beams, channels, tubes, and the like. The apparatus  100  includes a carriage  120 . The carriage  120  is movably supported on the chassis  110 . More specifically, the carriage  120  is adapted for movement relative to the chassis  110  by way of one or more guides and/or tracks and the like (not shown) that are configured to facilitate movement of the carriage relative to the chassis. The carriage  120  and/or the chassis  110  can be adapted to enable movement of at least a portion of the carriage in a plurality of dimensions relative to the chassis. According to the exemplary embodiment of the present disclosure, at least a portion of the carriage  120  is adapted to move only substantially horizontally relative to the chassis  110 , while another portion of the chassis is adapted to move both substantially horizontally and substantially vertically relative to the chassis. 
     The carriage  120  is adapted to carry a plurality of dunnage pieces  20 , and to place the dunnage pieces on the a stack unit  10 . The apparatus  100  includes a dunnage magazine  130 . The dunnage magazine  130  can be supported by the chassis  110 . Alternatively, the magazine  130  can be supported by a dedicated and/or separate support structure (not shown). The dunnage magazine  130  is adapted to accumulate and/or to contain therein a plurality of dunnage pieces  20  that are destined to be transferred to, or loaded onto, the carriage  120 . The dunnage magazine  130  is configured in a manner wherein the dunnage pieces  20  contained within the magazine can be selectively released therefrom, and to thereby drop or fall therefrom under the force of gravity into the carriage  120  when the carriage is to be loaded. 
     The apparatus  100  can include a magazine feed conveyor  140 . The feed conveyor  140  is adapted to supply and/or convey dunnage pieces  20  to the dunnage magazine  130 . According to one or more embodiments of the present disclosure, the feed conveyor  140  is adapted to selectively feed and/or load dunnage pieces  20  directly into the dunnage magazine  130 . The magazine feed conveyor  140  can be at least partially supported by the chassis  110 . Alternatively, the magazine feed conveyor  140  can be supported by a dedicated and/or separate support structure (not shown). The feed conveyor  140  can include, or can receive the dunnage pieces  20  from, an unscrambler and other related devices (not shown), which are adapted to unscramble and/or substantially align and/or straighten and/or space the dunnage pieces  20  on the feed conveyor as depicted. The unscrambler and other related devices are known to those of skill in the art. 
     The apparatus  100  can include a stack unit conveyor  150 . The stack unit conveyor  150  is adapted to convey thereon one or more stack units  10 . More specifically, the stack unit conveyor  150  is adapted to convey or move a stack unit  10  from an initial position  31  to a receiving position  32 . The initial position  31  is a position at which the stack unit is placed onto the stack unit conveyor  150 . Such placement of the stack unit  10  onto the stack unit conveyor  150  at the initial position  31  can be accomplished by one of a number of means such as, but not limited to, automatic outfeed mechanisms (not shown) associated with an automatic stacker (not shown) that forms the stack units. Alternatively, for example, the stack units  10  can be placed onto the stack unit conveyor  150  at the initial position  31  by a forklift (not shown). 
     The receiving position  32  is a position or range of positions of the stack unit  10  at which the carriage  120  places dunnage pieces  20  onto the stack unit. According to at least one embodiment of the present disclosure, the stack unit conveyor  150  is adapted to convey the stack units  10  beneath the carriage  120  and the chassis  110 , as depicted in  FIG. 2 . According to the exemplary embodiment of the present disclosure, the stack unit is located substantially beneath the chassis  110  when in the receiving position  32 , as depicted. As is described in greater detail herein with reference to additional drawing figures, several dunnage pieces  20  are selectively released from the carriage  120  and placed onto a stack unit  10  that is parked or temporarily stopped at the receiving position  32 , according to one or more embodiments of the present disclosure. It is to be understood, however, that according to alternative embodiments of the present disclosure, the apparatus  100 , including the carriage  120 , is adapted to place dunnage pieces  20  onto a moving stack unit  10 , which does not stop or park as it travels beneath the chassis  110 . 
     The stack unit conveyor  150  is adapted to convey or move a stack unit  10  from the receiving position  32  to a removal position  33 . The removal position  33  is a position at which the stack unit  10  is removed from the stack unit conveyor  150 . The stack unit  10  can be removed from the stack unit conveyor  150  by one of a number of possible removal means. By way of example only, the stack unit  10  can be removed from the stack unit conveyor  150  at the removal position  33  by a forklift or the like (not shown). According to the exemplary embodiment of the present disclosure, dunnage pieces  20  have been placed by the carriage  120  onto at least a portion of the stack units  10 , which are then removed from the stack unit conveyor  150  at the removal position  33  with the dunnage pieces in place on top of the stack units. 
     The apparatus  100  can include a control system  160 , which is described in greater detail hereinbelow with respect to additional drawing figures. With continued reference to  FIG. 2 , the control system  160  includes one or more suitable data links or communication links  169 . The data link  169  is adapted to carry and/or distribute and/or transmit data signals and/or control signals and/or input signals and/or output signals that are generated and/or transmitted and/or received by one or more components of the control system  160 . The control system  160  is adapted to control operation of the apparatus  100  according to an associated control scheme, whereby the apparatus operates to place dunnage pieces  20  onto a stack unit  10 . According to the exemplary embodiment of the present disclosure, the control system  160  includes a plurality of input devices and output devices (not shown). Input devices can include, for example, one or more types of sensors adapted to generate input signals indicative of one or more detected operational parameters of the apparatus  100 . Output devices can include, for example, one or more types of motors and/or actuators adapted to cause movement of various associated portions of the apparatus in response to operational control signals or output signals generated by the control system  160   
     According to one embodiment of the present disclosure, and by way of example only, a description of various operation and/or control functions of the control system  160  and other portions of the exemplary apparatus  100  is provided hereinbelow with reference to  FIG. 2 . Initially, for example, the control system  160  generates a querry to determine whether the dunnage magazine  130  needs to be loaded with dunnage pieces  20 . This determination can be facilitated, for example, by one or more sensors (not shown) adapted to detect whether a predetermined quantity of dunnage pieces  20  are contained within the magazine  130 . The control system  160  causes the magazine feed conveyor  140  to bring dunnage pieces  20  into the dunnage magazine  130  in response to determining that the dunnage magazine needs to be loaded with dunnage pieces. The control system  160  causes the feed conveyor  140  to stop bringing dunnage pieces  20  to the magazine  130  in response to determining that the magazine contains a predetermined quantity of dunnage pieces. 
     The control system  160  generates a querry to determine whether the carriage  120  needs to be loaded with dunnage pieces  20 . This determination can be facilitated, for example, by one or more sensors (not shown) that are adapted to detect presence of a predetermined quantity of dunnage pieces  20  contained by the carriage  120 . In response to determining that the carriage  120  needs to be loaded, a querry is made to determine whether the carriage  120  is in the loading position. The carriage loading position is a position of the carriage  120  relative to the magazine  130 , at which the carriage is able to receive dunnage pieces  20  that are released from the magazine. A process of determining and/or tracking the position of the carriage  120  relative to the magazine  130  can be facilitated by one or more of a number of means including, but not limited to, employing an encoded stepper motor (not shown) as a prime mover for the carriage relative to the magazine, and/or employing one or more sensors (not shown) adapted to detect the presence of the carriage at respective predetermined locations. 
     The control system  160  causes the carriage  120  to move to the loading position in response to determining that the carriage  120  needs to be loaded with dunnage pieces  20 , and that the carriage is not at the loading position. In response to determining that the carriage  120  is at the loading position, the control system  160  causes the magazine  130  to release therefrom a predetermined number of dunnage pieces  20 . The control system  160  causes the carriage  120  to receive the dunnage pieces  20  from the magazine  130 , and to stow the received dunnage pieces in preparation for placement of the dunnage pieces onto a stack unit  10 . The process of releasing the dunnage pieces  20  from the magazine  130  and receiving the dunnage pieces into the carriage  120 , and stowing the dunnage pieces, is described in greater detail hereinbelow with respect to additional drawing figures. 
     Still referring to  FIG. 2 , the control system  160  generates a querry to determine whether a stack unit  10  is approaching the dunnage placing position  32  from the initial position  31 . A process of determining and/or tracking respective positions of stack units  10  on the stack conveyor  150  can be facilitated by one or more of a number of manners including, but not limited to, employing one or more sensors (not shown) adapted to detect or track relative positions of the stack units. In response to determining that a stack unit  10  is approaching the dunnage placing position  32 , a query is generated to determine whether dunnage  20  is to be placed on the approaching stack unit. Such a determination can be made according to one of a number of criteria. For example, the control system  160  can receive inputs or instructions from a human operator regarding which particular stack units  10  are to have dunnage pieces  20  placed upon them. Alternatively, for example, the control system  160  can make such a determination according to a predetermined scheme or algorithm (not shown). By way of example only, such an algorithm can specify that dunnage pieces  20  are to be placed only on every other stack unit  10  that passes through the receiving position  32 . 
     With continued reference to  FIG. 2 , the control system  160  generates a querry to determine whether a given stack unit  10  that is supported on the stack conveyor  150  is approaching the receiving position  32 . The determination of whether a stack unit  10  is approaching the dunnage placing position  32  can be facilitated by one or more sensors (not shown) adapted to detect whether a stack unit  10  is at a predetermined position on the stack conveyor  150 . In response to determining that the approaching stack unit  10  is not to have dunnage pieces  20  placed thereon, the control system  160  commands the stack conveyor  150  to move the approaching stack unit through the receiving position  32 , and on to the removal position  33  without receiving dunnage pieces. 
     Alternatively, the control system  160  commands the stack unit conveyor  150  to park the approaching stack unit  10  at the dunnage receiving position  32  in response to determining that the approaching stack unit is to have dunnage pieces  20  placed upon it. The control system  160  then generates a querry to determine if the approaching stack unit  10  has arrived at the dunnage receiving position  32 . This determination can be facilitated by use of one or more sensors (not shown) adapted to detect and/or track the position of one or more stack units  10  on the track conveyor  150 . In response to determining that the stack unit  10  has arrived at the receiving position  32 , the control system  160  causes the carriage  120  to place dunnage pieces  20  onto the stack unit. According to at least one embodiment of the present disclosure, the carriage  120  places dunnage pieces  20  onto the stack unit  10  at predetermined positions relative to the stack unit. 
     With continued reference to  FIG. 2 , the control system  160  generates a querry to determine whether the carriage  120  has completed placement of dunnage pieces  20  on the stack unit  10 . In response to determining that the carriage  120  has completed placement of dunnage pieces  20  onto the stack unit  10 , the control system  160  causes the carriage to return to the loading position. The control system  160  also causes the stack conveyor  150  to move the stack unit  10  out of the dunnage receiving position  32  and toward the removal position  33 , in response to determining that the carriage  120  has finished placing dunnage pieces  20  onto the stack unit  10 . When the stack unit  10  arrives at the removal position  33 , the stack unit can be removed from the stack conveyor  150  by a forklift or the like. 
     The process of placing dunnage pieces  20  onto stack units  10  can be performed substantially continually. More specifically, a substantially continuous succession of stack units  10  can be placed, one-after-another, onto the stack conveyor  150  at the initial position  31 . This substantially continuous succession of stack units  10  can be moved by the stack conveyor  150  from the initial position  31  to the dunnage receiving position  32 , and then from the receiving position to the removal position  33 . Dunnage pieces  20  can be placed onto at least a selected number of the substantially continuous succession of stack units  10  at the receiving position  32 . The substantially continuous succession of stack units  10  can be removed, one-after-another, from the stack conveyor  150  at the removal position  33 . 
     Turning now to  FIG. 3 , a side elevation view depicts a dunnage magazine  130  in isolation according to one or more embodiments of the present disclosure. For illustrative purposes and for clarity, the depiction in  FIG. 3  of the magazine  130  is simplified. Moreover, one or more components and/or portions of components of the magazine  130 , which are not necessary for understanding the configuration and/or operational characteristics of the magazine, have been omitted. The magazine  130  includes at least two guides or guide sets. More specifically, the magazine  130  includes at least one first guide  131  and at least one second guide  132 . Each first guide  131  defines thereon a first guide surface  133 . Similarly, each second guide  132  defines thereon a second guide surface  134 . According to the exemplary embodiment of the present disclosure, the magazine  130  includes a plurality of first guides  131  and a plurality of second guides  132 . The first guides  131  of the exemplary magazine  130  are arranged in mutually juxtaposed alignment, wherein only one first guide is visible in the view depicted by  FIG. 3 . Similarly, the second guides  132  of the exemplary magazine  130  are in mutually juxtaposed alignment, wherein only one second guide is visible in the view depicted by  FIG. 3 . 
     Each of the guides  131 ,  132  can be formed form a suitably durable material such as, for example, steel plate. According to the exemplary embodiment of the present disclosure, at least one first guide  131  is associated with at least one second guide  132 . More specifically, the associated first guide  131  and second guide  132  are positioned relative to each other, wherein the first guide surface  133  and the associated second guide surface  134  are opposed or spaced apart so as to define therebetween an elongated path  138 . The path  138  is bounded on each side thereof by the first guide surface  133  and the second guide surface  134 , respectively. The guides  131 ,  132  are tied together in substantially fixed relation to each other by being affixed to one or more braces, frameworks or other such structures, which are omitted for clarity. 
     With continued reference to  FIG. 3 , the magazine  130  defines a lower end  135  and an opposite upper end  139 . According to the exemplary embodiment of the disclosure, the lower end  135  is substantially in the form of a lower opening of the path  138 , while the upper end  139  is substantially in the form of an upper opening of the path. More specifically, the lower end  135  can be described as the magazine exit, while the upper end  139  can be described as the magazine entrance. A study of  FIG. 3  reveals that at least a portion of each of the guide surfaces  133 ,  134  as well as the path  138  are substantially curved or arcuate. According to the exemplary embodiment of the present disclosure, the path  138 , and the guide surfaces  133 ,  134 , transition from a nearly horizontal orientation proximate the upper end  139  to a substantially vertical orientation proximate the lower end  135 . 
     The magazine  130  can include one or more sensors (not shown). At least one of the sensors is adapted to detect the presence of one or more dunnage pieces (not shown) within the magazine  130 . According to one or more embodiments of the present disclosure, at least one sensor is adapted to detect the presence of a dunnage piece (not shown) at a given location or position within the magazine  130 . By way of example only, one or more sensors can be at least one of a proximity sensor, a photoelectric sensor, and a limit switch. The sensors can be supported by the magazine  130 . By way of example only, the sensors can be supported on one or more of the guides  131 ,  132 . It is to be understood however, that the sensors associated with the magazine  130  can be supported on components and/or structure other than the magazine itself, according to one or more alternative embodiments of the present disclosure. 
     Still referring to  FIG. 3 , the magazine  130  is configured so that dunnage pieces (not shown) are introduced or loaded into the magazine through the upper end  139 , and are released from the magazine through the lower end  135 . According to one or more embodiments of the present disclosure, the dunnage pieces are introduced into the upper end  139  from a substantially horizontal direction. For example, dunnage pieces can be introduced into the upper end  139  from a substantially horizontally oriented conveyor  140 , as is seen from a study of  FIG. 2 . Returning to  FIG. 3 , dunnage pieces are released in a substantially vertical direction from the lower end  135  of the magazine  130 . According to the exemplary embodiment of the present disclosure, dunnage pieces are released from the lower end  135  to thereby drop in a substantially vertically downward direction under the force of gravity. 
     With continued reference to  FIG. 3 , the magazine  130  includes at least one gate member. More specifically, the magazine  130  includes at least one first gate member  136 . The exemplary magazine  130  also includes at least one second gate member  137 . The gate members  136 ,  137  are operatively supported by the magazine  130 . According to the exemplary embodiment of the present disclosure, at least one of the first gate members  136  and at least one of the second gate members  137  are be pivotally supported by one of the guides, such as the second guide  132 , as shown. At least one of the first and second gate members  136 ,  137  is adapted to facilitate selective release of dunnage pieces (not shown) from the magazine  130 . According to the exemplary embodiment of the present disclosure, the first and second gate members  136 ,  137  are adapted for mutually complementary operation in facilitating selective release of one or more dunnage pieces (not shown) from the lower end  135  of the magazine  130 . It is to be noted that both the first gate member  136  and the second gate member  137  are depicted in  FIG. 3  to be in respective open positions. 
     Turning now to  FIG. 4 , another side elevation view depicts the magazine  130 , which is depicted in  FIG. 3 . The respective views of the magazine  130  in  FIGS. 3 and 4  are substantially the same, except that  FIG. 4  depicts the first and second gate members  136 ,  137  in respective closed positions, while  FIG. 3  depicts the first and second gate members in respective opened positions. Movement of the gate members  136 ,  137  between the respective opened and closed positions can be facilitated, for example, by use of respective actuators (not shown) operatively connected between the second guide  132  and the associated gate member, for example. An additional difference between  FIGS. 3 and 4  is that  FIG. 4  depicts the magazine  130  in a loaded state, compared with  FIG. 3  which depicts the magazine in an empty state. More specifically,  FIG. 4  depicts a plurality of dunnage pieces  20  contained within the magazine  130 , while  FIG. 3  depicts no dunnage pieces. 
     With continued study of  FIG. 4 , the first gate member  136  can be a blocker gate, while the second gate member  137  can be a gripper gate. The blocker gate, which is exemplified by the first gate member  136 , is adapted to substantially block the path of any dunnage pieces  20  that are located above the first gate member and within the magazine. By contrast, the gripper gate, which is exemplified by the second gate member  137 , is adapted to substantially laterally impinge upon, or grip, a given dunnage piece  20  to thereby substantially immobilize the given dunnage piece. As is evident from further study of  FIG. 4 , the second gate member  137  can have a substantially pointed or sharp profile that is adapted to facilitate gripping and/or immobilization of the dunnage piece  20  against which the second gate member impinges. 
     With reference now to both  FIGS. 3 and 4 , a description of a general operational sequence of the magazine  130  according to the exemplary embodiment of the present disclosure follows. Initially, the magazine  130  is empty, with the first gate  136  and the second gate  137  being in respective open positions (as depicted in  FIG. 3 ). In preparation for loading dunnage pieces  20  into the magazine  130 , the first gate  136  is moved to a closed position (as depicted in  FIG. 4 ) to substantially block the lower end  136 , while the second gate  137  remains open. Dunnage pieces  20  are introduced or loaded into the magazine  130  through the upper end  139 . The dunnage pieces  20  can be introduced into the magazine  130  by one of a number of means. According to the exemplary embodiment of the present disclosure, the dunnage pieces  20  are loaded into the upper end  139  of the magazine  130  by the dunnage feed conveyor  140  (shown in  FIG. 2 ). 
     The magazine  130  can be configured in one of a number of specific dunnage capacities. A study of  FIG. 4  reveals that the exemplary dunnage magazine  130  is configured to have a capacity of five (5) dunnage pieces  20 . According to the exemplary embodiment of the present disclosure, the process of loading dunnage pieces  20  into the magazine  130  is temporarily stopped in response to detecting that the magazine  130  contains a predetermined number dunnage pieces. This predetermined number of dunnage pieces  20  can be, for example, a number of dunnage pieces equal to the capacity of the magazine  130 , which according to the exemplary embodiment of the present disclosure, is five (5) dunnage pieces. The process of loading dunnage pieces  20  into the magazine can be started in response to detecting that the number of dunnage pieces within the magazine  130  has fallen to a predetermined number which is less than the maximum capacity of the magazine. In response to a detecting that a predetermined number of dunnage pieces  20  have been loaded into the magazine  130 , the second gate member  137  is moved from an open position (as shown in  FIG. 3 ) to a closed position (as shown in  FIG. 4 ). By way of example only, the second gate member  137  is closed in response to detecting that five (5) dunnage pieces have been loaded into the magazine  130 . 
     Continued study of  FIG. 4  reveals that the first gate member  136 , when it is in the closed position, is adapted to at least partially support the dunnage pieces  20  that are in the magazine  130 . As is seen, the specific configuration of the magazine  130  causes all of the dunnage pieces  20  within the magazine to be arranged in a “single file” orientation. The first gate member  136 , when in the closed position, is in contact with the lowest of the dunnage pieces  20  within the magazine  130 . The second gate member  137 , when in the closed position, is in contact with the second lowest of the dunnage piece  20  within the magazine  130 . The second lowest of the dunnage pieces within the magazine  130  is immediately above the lowest of the dunnage pieces. The remainder of the dunnage pieces  20  are located substantially above the second lowest of the dunnage pieces. 
     As is explained in greater detail hereinbelow with respect to additional drawing figures, the dunnage pieces  20  within the magazine  130  can be selectively released therefrom. According to the exemplary embodiment of the present disclosure, the dunnage pieces  20  can be selectively released from the magazine  130  one-at-a-time. With reference to both  FIGS. 3 and 4 , the lowermost of the dunnage pieces within the magazine  130  is selectively released therefrom by moving the first gate member  136  from the closed position (as shown in  FIG. 4 ) to the open position (as shown in  FIG. 3 ), while the second gate member  137  remains in the closed position (as shown in  FIG. 4 ). This allows the lowermost of the dunnage pieces  20  within the magazine  130  to fall therefrom under the force of gravity through the lower end  135 , while the remainder of the dunnage pieces within the magazine are retained therein at least in part by action of the second gate member  137  as it remains closed. 
     After the lowermost of the dunnage pieces  20  within the magazine  130  is completely released therefrom, the first gate member  136  is moved from the open position to the closed position, while the second gate member  137  remains closed. After the first gate member  136  is fully closed, the second gate member  137  is opened to thereby allow the remaining dunnage pieces  20  to move downward under the force of gravity so that the lowermost of the dunnage pieces comes into contact with the first gate member  136 . After the lowermost of the dunnage pieces  20  comes into contact with the first gate member  136 , the second gate member  137  is moved to the closed position. The aforementioned process can be repeated as necessary to selectively release each dunnage piece  20  from the magazine  130 . Additional dunnage pieces  20  can be loaded into the magazine  130  through the upper end  139  in response to releasing a given number of dunnage pieces through the lower end  135 , according to at least one embodiment of the present disclosure. 
     Turning now to  FIG. 5 , a side elevation view depicts a carriage  120  in isolation according to one or more embodiments of the present disclosure. For illustrative purposes and/or for clarity, the depiction in  FIG. 5  of the carriage  120  is simplified. Moreover, one or more components and/or portions of components of the carriage  120 , which are not necessary for understanding the configuration and/or operational characteristics of the carriage, have been omitted. The carriage  120  includes at least two guides or guide sets. More specifically, the carriage includes at least one first guide  121  and at least one second guide  122 . Each first guide  121  defines thereon a first guide surface  123 . Similarly, each second guide  122  defines thereon a second guide surface  124 . According to the exemplary embodiment of the present disclosure, the carriage  120  includes a plurality of first guides  121  and a plurality of second guides  122 . The first guides  121  of the exemplary carriage  120  are arranged in mutually juxtaposed alignment, wherein only one first guide is visible in the view depicted by  FIG. 5 . Similarly, the second guides  122  of the exemplary carriage  120  are in mutually juxtaposed alignment, wherein only one second guide is visible in the view depicted by  FIG. 5 . 
     With continued reference to  FIG. 5 , each of the guides  121 ,  122  can be formed form a suitably durable material such as, for example, steel plate. According to the exemplary embodiment of the present disclosure, at least one first guide  121  is associated with at least one second guide  122 . More specifically, the associated first guide  121  and second guide  122  are positioned relative to each other, wherein the first guide surface  123  and the associated second guide surface  124  are opposed or spaced apart in order to at least partially define therebetween a plurality of dunnage positions, which are described hereinbelow. The guides  121 ,  122  are tied together in substantially fixed relation to each other by being affixed to one or more braces, frameworks or other such structures, which are omitted for clarity. 
     The carriage  120  defines a lower end or opening  128  and an opposite upper end or opening  129 . More specifically, the carriage lower end  128  can be described as the carriage exit, while the carriage upper end  129  can be described as the carriage entrance. A study of  FIG. 5  reveals that each of the guide surfaces  123 ,  124  of the exemplary carriage  120  are substantially vertical. The carriage  120  is configured so that dunnage pieces (not shown) are introduced or loaded into the carriage through the upper end  129 , and are released from the carriage through the lower end  128 . 
     The carriage  120  includes at least one gate, or gate member. According to the exemplary embodiment of the present disclosure, the carriage  120  includes at least one of each of a lower gate or gate member  125 , an intermediate gate or gate member  126 , and an upper gate or gate member  127 . The gate members  125 ,  126 ,  127  are operatively supported by the carriage  120 . According to at least one embodiment of the present disclosure, one or more of the gates  125 ,  126 ,  127  is operatively supported, respectively, on one or more of the guides  121 ,  122 . According to the exemplary embodiment, the gate members  125 ,  126 ,  127  are pivotally supported on the first guide  121 , as shown. It is to be understood, however, that other configurations of the gate members  125 ,  126 ,  127  are contemplated according to alternative embodiments of the present disclosure. By way of example only, one or more of the gate members  125 ,  126 ,  127  can have the form of sliding gates rather than pivoting gates. Each of the gate members  125 ,  126 ,  127  is adapted to alternately substantially support and selectively release, a respective dunnage piece (not shown), as is described in greater detail with respect to additional drawing figures hereinbelow. 
     With continued reference to  FIG. 5 , each of the gates  125 ,  126 ,  127  is selectively moveable between respective open positions and closed positions. For purposes of illustrating these open and closed positions, the lower gate  125  and the upper gate  127  are each depicted in respective closed positions, while the intermediate gate  126  is depicted in an open position. According to the exemplary embodiment of the disclosure, each of the gates  125 ,  126 ,  127  is movable between their respective closed positions and open positions by way of a pivoting movement of the gate member relative to the respective first guide member  121 , on which the gate members are supported. Such pivoting movement of the gates  125 ,  126 ,  127  is facilitated by one or more associated actuators (not shown) adapted to cause selective movement of respective gates according to one or more embodiments of the present disclosure. 
     Still referring to  FIG. 5 , each of the exemplary gate members  125 ,  126 ,  127  has a primary surface  98  and a secondary surface  99  defined thereon. The primary surface  98  is substantially straight and elongate. The secondary surface  99  is substantially straight and extends obliquely from the primary surface  98 . A study of  FIG. 5  reveals that when a given gate  125 ,  126 ,  127  is in the respective closed position, the primary surface  98  of the given gate will extend downwardly and toward the second guide surface  124  from the first guide surface  123 . It is also evident that the secondary surface  99  will have a substantially normal orientation relative to the first and second guide surfaces  123 ,  124  when the given gate  125 ,  126 ,  127  is in the closed position. By contrast, no substantial portion of a given gate  125 ,  126 ,  127  will extend past the first guide surface  123  toward the second guide surface  124  when the gate is in the closed position, as is evident from a study of  FIG. 5 . 
     With continued reference to  FIG. 5 , the carriage  120  can include one or more sensors (not shown). At least one sensor is adapted to detect the presence of one or more dunnage pieces (not shown) within the carriage  120 . According to at least one embodiment of the present disclosure, at least one is adapted to detect presence of a dunnage piece (not shown) at a given location or position within the carriage  120 . By way of example only, one or more sensors can be at least one of a proximity sensor, a photoelectric sensor, and a limit switch. The sensors can be supported by the carriage  120 . By way of example only, one or more sensors can be supported on one or more of the guides  121 ,  122 . It is to be understood however, that the sensors associated with the carriage  120  can be supported on components and/or structure other than the carriage itself, according to one or more alternative embodiments of the present disclosure. 
     Turning now to  FIG. 6 , another side elevation view depicts the carriage  120 , which is depicted in  FIG. 5 . The respective views of the carriage  120  in  FIGS. 5 and 6  are substantially the same, except that  FIG. 6  depicts all of the gate members  125 ,  126 ,  127  in respective closed positions, while  FIG. 5  depicts the lower gate member  125  and the upper gate member  127  in respective closed positions, while depicting the intermediate gate member  126  in an open position. An additional difference between  FIGS. 5 and 6  is that  FIG. 6  depicts the carriage  120  in a loaded state, compared with  FIG. 5  which depicts the carriage in an empty state. With reference to  FIG. 6 , a first dunnage piece  21 , a second dunnage piece  22 , and a third dunnage piece  23  are shown to be supported by the carriage  120 . 
     The first, second, and third dunnage pieces  21 ,  22 ,  23  are the same as the dunnage pieces  20  (shown in  FIGS. 1 and 2 ) described herein. However, the first, second, and third dunnage pieces  21 ,  22 ,  23  are described as such in order to facilitate understanding of operational aspects of the exemplary carriage  120 . With reference to  FIG. 6 , the first dunnage piece  21  is depicted in a lower dunnage position, in which the first dunnage piece is at least partially retained by the lower gate  125 . The second dunnage piece  22  is depicted in an intermediate dunnage position, in which the second dunnage piece is at least partially retained by the intermediate gate  126 . Similarly, the third dunnage pieces  23  is depicted in an upper dunnage position, in which the third dunnage piece is at least partially retained by the upper gate  127 . It is to be understood that, during the process of loading the carriage  120  and during the process of placing dunnage pieces, each of the first, second, and third dunnage pieces  21 ,  22 ,  23  will occupy each of the upper, the intermediate, and the lower dunnage positions at various times during those processes. 
     With reference now to  FIGS. 3-6 , a description is provided of a general operational sequence of releasing dunnage pieces from the magazine  130  and receiving the dunnage pieces into the carriage  120 , and stowing the dunnage pieces on the carriage. Initially, the carriage  120  is empty, with no dunnage pieces supported by the carriage, and with the gates  125 ,  126 ,  127  closed. During the process of loading the carriage  120 , the carriage is positioned below the magazine  130  (shown in  FIGS. 3 and 4 ). More specifically, during the process of loading the carriage  120  (shown in  FIGS. 5 and 6 ), the carriage is positioned (shown in  FIGS. 3 and 4 ) so that the carriage entrance  129  is below and in substantial alignment with the magazine exit  135 . This is because dunnage pieces  20 ,  21 ,  22 ,  23  are released, one-at-a-time, under the force of gravity from the magazine  130  through the magazine exit  135 , whereupon the dunnage pieces are received into the carriage  120  by way of the carriage entrance  129 . 
     During the carriage loading process, the magazine  130  can be operated in the manner generally described hereinabove with respect to  FIGS. 3 and 4 , wherein dunnage pieces are released from the magazine one-at-a-time, and are allowed to drop under the force of gravity through the magazine exit  135 . With reference to  FIGS. 3-6 , the exemplary carriage loading process begins when the first dunnage piece  21  is released from the magazine  130  and is allowed to drop under the force of gravity through the magazine exit  135  and into the carriage  120  through the carriage entrance  129 . The first dunnage piece  21  then comes to rest in the upper dunnage position where it is supported, at least partially, by the upper gate  127 , which is in the closed position. The upper gate  127  then opens to allow the first dunnage piece  21  to drop under the force of gravity into the intermediate dunnage position where it is supported, at least partially, by the intermediate gate  126 . After the first dunnage piece  21  is released from the upper dunnage position, the upper gate  127  moves back to the closed position. 
     In response to the upper gate  127  attaining a closed position, the magazine  130  releases the second dunnage piece  22  through the magazine exit  135 . From the magazine  130 , the second dunnage piece  22  drops under to force of gravity through the carriage entrance  129 , and comes to rest in the upper dunnage position in which it is at least partially supported by the upper gate  127 , which is in the closed position. Meanwhile, in response to the first dunnage piece  21  coming to rest in the intermediate dunnage position, the intermediate gate  126  opens to allow the first dunnage piece  21  to drop under the force of gravity to the lower dunnage position in which it is at least partially supported by the lower gate  125 . After the first dunnage piece  21  is released from the intermediate position, the intermediate gate  126  moves back to the closed position. 
     In response to the second dunnage piece  22  coming to rest in the upper dunnage position, the upper gate  127  opens to allow the second dunnage piece to drop under the force of gravity to the intermediate dunnage position in which it is at least partially supported by the intermediate gate  126 . After the second dunnage piece  22  is released from the upper position, the upper gate  127  is moved back into the closed position. In response to the upper gate  127  attaining a closed position, the magazine  130  releases the third dunnage piece  23  through the magazine exit  135 . From the magazine  130 , the third dunnage piece  23  drops under to force of gravity through the carriage entrance  129 , and comes to rest in the upper dunnage position in which it is at least partially supported by the upper gate  127 , which is in the closed position. The carriage  120  is now in a loaded state as depicted in  FIG. 6 , wherein the first dunnage piece  21  is stowed in the lower dunnage position proximate the lower gate  125 , and the second dunnage piece  22  is stowed in the intermediate dunnage position proximate the intermediate gate  126 , and the third dunnage piece  23  is stowed in the upper dunnage position proximate the upper gate  127 . 
     A description of an exemplary procedure for releasing dunnage pieces  21 ,  22 ,  23  from the carriage  120  now follows. Such dunnage releasing procedure can be employed during placement of the dunnage pieces onto a stack unit (shown in  FIG. 1 ), for example. With reference to  FIG. 6 , the carriage  120  is moved into a first placement position. The procedure for moving the carriage  120  into one or more various dunnage placement positions is described hereinbelow with reference to additional drawing figures. Still referring to  FIG. 6 , the first dunnage piece  21  is released from the carriage  120  in response to the carriage attaining the placement position for the first dunnage piece. The first dunnage piece  21  is released from the carriage  120  by causing the lower gate  125  to move from the closed position to the open position. Movement of the lower gate member  125  to the open position will allow the first dunnage piece  21  to drop downward under the force of gravity so as to be released from the lower dunnage position. In response to complete release of the first dunnage piece  21  from the lower dunnage position, the lower gate  125  is closed. 
     In response to the lower gate  125  attaining the closed position, the intermediate gate  126  is caused to move to the open position. Moving the intermediate gate  126  to the open position allows the second dunnage piece  22  to drop downward under the force of gravity from the intermediate dunnage position. The second dunnage piece  22  drops from the intermediate dunnage position into the lower dunnage position proximate the lower gate  125 , which is in the closed position. In response to the second dunnage piece  22  coming to rest in the lower dunnage position, the intermediate gate  126  is caused to move to the closed position. In response to the intermediate gate  126  attaining the closed position, the upper gate  127  is caused to move to the open position. Movement of the upper gate  127  to the open position allows the third dunnage piece  23  to drop downward under the force of gravity from the upper dunnage position. The third dunnage piece  23  drops from the upper dunnage position into the intermediate dunnage position proximate the intermediate gate  126 , which is in the closed position. At this point in the dunnage release procedure, the first dunnage piece  21  has been released from the carriage  120 , while the second dunnage piece  22  has moved from the intermediate dunnage position to the lower dunnage position proximate the lower gate  125 , and the third dunnage piece  23  has moved from the upper dunnage position to the intermediate dunnage position proximate the intermediate gate  126 . 
     In response to releasing the first dunnage piece  21  from the carriage  120 , the carriage  120  is caused to move toward the placement position for the second dunnage piece  22 . During movement of the carriage  120  to the placement position for the second dunnage piece  22 , the second dunnage piece  22  and the third dunnage piece  23  can be dropped to the lower dunnage position and the intermediate dunnage position, respectively, as described hereinabove. In response to the arrival of the carriage  120  at the placement position for the second dunnage piece  22 , the lower gate  125  is caused to move to the open position. Movement of the lower gate  125  to the open position allows the second dunnage piece  22  to drop downward from the lower dunnage position so as to be released from the carriage  120 . In response to complete release of the second dunnage piece  22  from the carriage  120 , the lower gate  125  is caused to move back to the closed position. 
     In response to the lower gate  125  attaining the closed position, the intermediate gate is caused to move to the open position. Movement of the intermediate gate  126  to the open position allows the third dunnage piece  23  to drop downward from the intermediate dunnage position to the lower dunnage position proximate the lower gate  125 . In response to the third dunnage piece  23  arriving at the lower dunnage position, the intermediate gate  126  is moved back to the closed position. In response to release of the second dunnage piece  22  from the carriage  120 , the carriage is caused to begin moving toward the placement position for the third dunnage piece. Repositioning of the third dunnage piece  23  from the intermediate position to the lower position can be performed during movement of the carriage  120  toward the placement position for the third dunnage piece. 
     In response to arrival of the carriage  120  at the placement position for the third dunnage piece  23 , the lower gate  125  is caused to move to the open position. Movement of the lower gate  125  to the open position allows the third dunnage piece  23  to drop downward from the lower dunnage position so as to be released from the carriage  120 . In response to complete release of the third dunnage piece  23  from the carriage  120 , the lower gate  125  is caused to move back to the closed position. Also, in response to release of the third dunnage piece  23  from the carriage  120 , the carriage is caused to move back toward the magazine  130  (shown in  FIG. 2 ) to the loading position at which additional dunnage pieces are loaded into the carriage as described hereinabove. 
     With reference now to  FIGS. 7-10 , a series of four side elevation views depicts the apparatus  100 . The depiction of the apparatus  100  in  FIGS. 7-10  is simplified and various components and/or portions of components have been omitted for clarity. All of the views of  FIGS. 7-10  are substantially similar, except that the carriage  120  and each of the dunnage pieces  21 ,  22 ,  23  are shown in different respective positions in each of the four views. The series of views depicted by  FIGS. 7-10  illustrates an operational sequence of the carriage as it places dunnage pieces on a stack unit  10 . More specifically, the view of  FIG. 7  depicts the carriage  120  in a loading position, while the view of  FIG. 8  depicts the carriage in a first dunnage placing position. The view of  FIG. 9  depicts the carriage  120  in a second dunnage placing position, while the view of  FIG. 10  depicts the carriage in a third dunnage placing position. 
     With reference to  FIG. 7 , the carriage  120  is depicted in a dunnage loading position. As is seen from a study of  FIG. 7 , the carriage  120  is positioned below the magazine  130 . The carriage  120  is also shown to be in substantial alignment with the magazine  130  to facilitate loading of dunnage pieces into the carriage from the magazine. As is depicted in  FIG. 7 , the carriage  120  is in a loaded state and contains a first dunnage piece  21  in the lower dunnage position proximate the lower gate  125 . The carriage  120  also contains a second dunnage piece  22  in the intermediate dunnage position proximate the intermediate gate  126 , and a third dunnage piece  23  in the upper dunnage position proximate the upper gate  127 . The dunnage pieces  21 ,  22 ,  23  can be loaded into the carriage  120  from the magazine  130  as described hereinabove with reference to  FIGS. 3-6 . As is depicted in  FIG. 7 , a stack unit  10  is in the receiving position, and the carriage  120  is ready to begin a placing dunnage pieces onto the stack unit. 
     Turning now to  FIG. 8 , the carriage  120  is depicted in a first dunnage placing position. That is, the carriage  120  has moved, or to has been repositioned relative to the chassis  110 , from the dunnage loading position (depicted in  FIG. 7 ) to a first dunnage placement position (depicted in  FIG. 8 ). According to the exemplary embodiment of the present disclosure, movement of the carriage  120  from the loading position to the first dunnage placement position includes an initial movement in a substantially horizontal direction followed by movement in a substantially vertical downward direction. As is evident from a study of  FIG. 8 , the carriage  120  has extended substantially vertically downward from the chassis  110 . This vertical extension capability of the carriage is accomplished by way of one or more mechanical components such as, for example, tracks, guides, telescoping rails, followers, etc. (not shown). 
     The exemplary carriage  120  is caused to move relative to the chassis  110  both vertically and horizontally by way of one or more various devices including, but not limited to, actuators, motors, mechanical transmissions, and the like (not shown). The carriage  120  can reach the first dunnage placement position with the aid of one or more sensors (not shown) adapted to detect the position of the carriage relative to the stack unit  10 . For example, according to the exemplary embodiment of the present disclosure, one or more sensors (not shown) are adapted to detect when the carriage  120  arrives at a predetermined vertical distance from the top of the stack unit  10 . When this predetermined vertical distance is detected, the carriage  120  can be caused to stop at a given vertical distance from the top of the stack unit  10  that is associated with the first placement position. As is depicted in  FIG. 8 , the lower gate  125  has opened to release the first dunnage piece  21  from the lower dunnage position of the carriage  120 , wherein the first dunnage piece has been placed onto the stack unit  10 . 
     Turning now to  FIG. 9 , the carriage  120  is depicted in a second dunnage position. That is, in response to releasing the first dunnage piece  21 , the carriage  120  has moved, or to has been repositioned, from the first dunnage placement position (depicted in  FIG. 8 ) to a second dunnage placement position (depicted in  FIG. 9 ). According to the exemplary embodiment of the present disclosure, movement of the carriage  120  from the first dunnage placement position to the second dunnage placement position includes an initial movement in a substantially vertically upward direction followed by movement in a substantially horizontal direction followed by movement in a substantially vertically downward direction. As is depicted in  FIG. 9 , the first dunnage piece  21  has remained at the position in which it was placed by the carriage  120  before the carriage moved to the second dunnage placement position. 
     It is to be understood that, during movement of the carriage  120  from the first dunnage placement position to the second dunnage placement position, the second dunnage piece  22  is repositioned from the intermediate dunnage position proximate the intermediate gate  126  to the lower dunnage position proximate the lower gate  125 . Additionally, during this movement of the carriage  120 , the third dunnage piece  23  is repositioned from the upper dunnage position proximate the upper gate  127  to the intermediate dunnage position proximate the intermediate gate  126 . Further study of  FIG. 9  reveals that the lower gate  125  has opened to release the second dunnage piece  22  from the lower dunnage position of the carriage  120 , wherein the second dunnage piece has been placed onto the stack unit  10 . 
     Turning now to  FIG. 10 , the carriage  120  is depicted in a third dunnage placement position. That is, in response to releasing the second dunnage piece  22 , the carriage  120  has moved, or has been repositioned, from the second dunnage placement position (depicted in  FIG. 9 ) to a third dunnage placement position (depicted in  FIG. 10 ). According to the exemplary embodiment of the present disclosure, movement of the carriage  120  from the second dunnage placement position to the third dunnage placement position includes an initial movement in a substantially vertically upward direction followed by movement in a substantially horizontal direction followed by movement in a substantially vertically downward direction. 
     As is depicted in  FIG. 10 , the second dunnage piece  22  has remained at the position on the stack unit  10  in which it was placed by the carriage  120  before the carriage moved to the third dunnage placement position. It is to be understood that, during movement of the carriage  120  from the second dunnage placement position to the third dunnage placement position, the third dunnage piece  23  is repositioned from the intermediate dunnage position proximate the intermediate gate  126  to the lower dunnage position proximate the lower gate  125 . Further study of  FIG. 10  reveals that the lower gate  125  has opened to release the third dunnage piece  23  from the lower dunnage position of the carriage  120 , wherein the third dunnage piece has been placed onto the stack unit  10 . 
     With reference now to  FIGS. 7 and 10 , the carriage  120  is empty after releasing the third dunnage piece  23  at the third dunnage placement position. That is, as described hereinabove, the first, second, and third dunnage pieces  21 ,  22 ,  23  have been released from the carriage  120 , and have been placed onto the stack unit  10 , as depicted in  FIG. 10 . In response to releasing the third dunnage piece  23 , the carriage  120  is caused to return, or move back, to the carriage loading position beneath the magazine  130 , which position is depicted in  FIG. 7 . Also, in response to release of the third dunnage piece  23  from the carriage  120 , the stack unit  10  is moved from beneath the chassis  110 . More specifically, for example, the stack unit  10  can be moved to the stack unit removal position  33  as is described hereinabove, and which position is depicted in  FIG. 2 . 
     Upon arrival of the carriage  120  at the carriage loading position (depicted in  FIG. 7 ), the carriage is again loaded with dunnage pieces  20  from the magazine  130  as is described hereinabove. While the carriage  120  is returning to the carriage loading position and/or while the carriage is receiving dunnage pieces  20  from the magazine  130 , another stack unit  10 , which is to have dunnage pieces placed upon it, is moved into the receiving position  32  (as is depicted in  FIG. 2 ). The above-described procedure of causing the carriage  120  to move to the first, second, and third dunnage placing positions, to thereby place the first second and third dunnage pieces  21 ,  22 ,  23  onto the stack unit  10 , can be repeated in response to detecting that the carriage  120  is fully loaded with the first, second, and third dunnage pieces, and in response to detecting that the stack unit  10  is in the receiving position substantially beneath the chassis  10 . The above-described procedure can be repeated as desired to place dunnage pieces  20 ,  21 ,  22 ,  23  onto respective stack units  10 . 
     Turning now to  FIG. 11 , a schematic view depicts the control system  160  in isolation, according to at least one embodiment of the present disclosure. The exemplary control system  160  includes a processor  161  and a memory device  162 . The control system  160  includes a set of computer-executable instructions  163  that are stored on the memory device  162 . The set of computer-executable instructions  163  can be in the form of a computer program, for example. The computer-executable instructions  163  are accessible by the processor  161 , whereby the processor can execute the computer executable instructions to facilitate operation of the apparatus  100  (shown in  FIG. 2 ). The computer executable instructions  163  can contain one or more algorithms in accordance with which one or more components of the apparatus  100  are operated or moved. 
     Still referring to  FIG. 11 , the control system  160  includes at least one operator input device  164 . The operator input device  164  is adapted to facilitate input of control parameters from a human operator to the processor  161  and/or to the memory device  162  and/or to the computer-executable instructions  163 . The operator input device  164  can have at least one of a number of configurations such as, for example, that of a keyboard or a touch screen. The control system  160  also includes at least one machine input device  165 . The machine input device  165  is adapted to generate and/or collect one or more various types of data that is sent to the processor  161 . The input device  165  can have at least one of a number of configurations such as, for example, that of a sensor, an encoder, or a counter. 
     The control system  160  includes at least one actuator and/or motor  166 . The actuator and/or motor  166  is adapted to facilitate movement of one or more components of the apparatus  100  (shown in  FIG. 2 ) through application of mechanical force and/or power to cause such movement. The actuator and/or motor  166  can include various components and/or subsystems required for operation, which can include, for example, relays, power supplies (e.g. electrical, pneumatic, hydraulic), mechanical linkages, and mechanical transmissions. The actuator and/or motor  166  can have at least one of a number of configurations such as, for example, linear motors, stepper motors, pneumatic cylinders, hydraulic cylinders, and solenoids. The actuator and/or motor  166  is an output device and is adapted to carry out commands generated by the processor  161 . The commands can be in the form of output signals, for example. 
     With continued reference to  FIG. 11 , the control system  160  can include one or more data links  169 . The data links  169  are adapted to transmit or carry data signals between two or more components of the control system  160 . Each data link  169  is connected between two or more components of the control system  160  to facilitate transmission therebetween of one or more types of data in the form of data signals. The data transmitted and/or carried by the data links  169  can be in the form of output or control signals, and input signals, for example. 
     With reference now to  FIGS. 2-11 , the exemplary apparatus  100  includes a plurality of machine input devices  165  (shown in  FIG. 11 ) that are positioned relative to one or more components of the apparatus to thereby facilitate substantial automatic operation of the apparatus. It is to be understood that the machine input devices  165  are shown schematically only in  FIG. 11 , and that the machine input devices have been omitted from other views in the interest of clarity. By way of example only, one or more machine input devices  165  that are in the form of sensors can be positioned to detect whether a predetermined number of dunnage pieces  20  are within the magazine  130 . By way of further example, one or more machine input devices  165  that are in the form of sensors can be positioned to detect whether one or more dunnage pieces  20 ,  21 ,  22 ,  23  is in one or more dunnage positions within the carriage  120 . More specifically, one or more machine input devices  165  that are in the form of sensors can be positioned to determine whether a respective dunnage piece  20 ,  21 ,  22 ,  23  is in each of the lower dunnage position proximate the lower gate  125 , the intermediate dunnage position proximate the intermediate gate  126 , and the upper position proximate the upper gate  127 . 
     According to at the exemplary embodiment of the present disclosure, one or more machine input devices  165  can be positioned to determine the elevation and/or vertical position of the carriage relative to a stack unit  10  at the receiving position  32 . At least one machine input device  165  can be positioned to determine a location or position of a stack unit  10  on the stack unit conveyor  150 . By way of example, only, one or more matching input devices  165  can be positioned to determine whether a stack unit  10  is in the dunnage placement position  32 , as depicted in  FIG. 2 . Each of the machine input devices  165  of the control system  160  is adapted to initiate generation of a data signal and transmission of that data signal to the processor  161 . Such data signals from the machine input devices  165  contain data indicative of one or more operational parameters that are usable by the processor  169  in making operational decisions. It is to be understood that additional and/or alternative implementations of the input devices  165  are within the scope of respective alternative embodiments of the present disclosure. 
     With continued reference to  FIGS. 2-11 , the apparatus  100  includes a plurality of actuators and/or motors  166  (shown in  FIG. 11 ) that are connected to one or more components of the apparatus to thereby facilitate substantial operation of the apparatus. It is to be understood that the actuators and/or motors  166  are shown schematically only in  FIG. 11 , and that the actuators and/or motors have been omitted from other views in the interest of clarity. By way of example only, one or more actuators and/or motors  166  can be adapted to cause selective movement and/or actuation and/or operation of one or more of: the carriage  120  relative to the chassis  110 ; the carriage gates  125 ,  126 ,  127  relative to the carriage; the magazine gates  136 ,  137  relative to the magazine; the magazine feed conveyor  140 ; and the stack conveyor  150 . Each of the actuators and/or motors  166  are adapted to receive control signals initiated by the processor  161 , and to cause movement of one or more associated components of the apparatus  100  in accordance with the control signals. It is to be understood that the control system  160  can include components and/or devices in addition to those that are specifically depicted and described herein. It is to be understood that additional and/or alternative implementations of the actuators and/or motors  166  are within the scope of respective alternative embodiments of the present disclosure. 
     According to at least one embodiment of the present disclosure, a method of placing dunnage pieces is provided. It is to be understood that the methods of placing dunnage pieces are commensurate with the description of the operation of the apparatus provided herein with reference to the drawing figures. For example, according to at least one embodiment of the present disclosure, a method of placing dunnage pieces includes providing an apparatus  100  that includes a chassis  110 , a carriage  120 , a dunnage magazine  130 , and a control system  160 . The carriage  120  is movably supported by the chassis  110  and is adapted to receive dunnage pieces  20 ,  21 ,  22 ,  23  from the magazine  130 . The carriage  120  includes a lower gate  125 , an intermediate gate  126  substantially above the lower gate, and an upper gate  127  substantially above the intermediate gate. The control system  160  is adapted to control operation of the apparatus  100 , and includes a memory device  162  and a set of computer-executable instructions  163  stored on the memory device and adapted to cause the control system to operate the apparatus. The dunnage magazine  130  is adapted to contain therein a plurality of dunnage pieces  20 ,  21 ,  22 ,  23 , and is further adapted to selectively release the contained dunnage pieces. 
     The method includes causing the magazine  130  to release a first dunnage piece  21  into an upper dunnage position in the carriage  120  proximate the upper gate  127 , and causing the upper gate  127  to open to release the first dunnage piece  21  from the upper dunnage position into an intermediate dunnage position in the carriage  120  proximate the intermediate gate  126 . The method includes causing the intermediate gate  126  to open to release the first dunnage piece  21  from the intermediate dunnage position into a lower dunnage position in the carriage  120  proximate the lower gate  125 , and causing the magazine  130  to release a second dunnage piece  22  into the upper dunnage position proximate the upper gate  127 . 
     The method further includes causing the upper gate  127  to open to release the second dunnage piece  22  from the upper dunnage position into the intermediate dunnage position proximate the intermediate gate  126 , and causing the magazine  130  to release a third dunnage piece  23  into the upper dunnage position proximate the upper gate  127 . The method includes causing the lower gate  125  to open to release the first dunnage piece  21  from the lower dunnage position, thereby placing the first dunnage piece. The method can includes placing the first dunnage piece  21  onto a stack unit  10 . 
     The method also includes causing the intermediate gate  126  to open to release the second dunnage piece  22  from the intermediate dunnage position into the lower dunnage position proximate the lower gate  125 , and causing the upper gate  127  to open to release the third dunnage piece  23  from the upper dunnage position into the intermediate dunnage position proximate the intermediate gate  126 . The method further includes causing the lower gate  125  to open to release the second dunnage piece  22  from the lower dunnage position, thereby placing the second dunnage piece. The method can include placing the second dunnage piece  22  onto the stack unit  10 . 
     The method includes causing the intermediate gate  126  to open to release the third dunnage piece  23  from the intermediate dunnage position into the lower dunnage position proximate the lower gate  125 , and causing the lower gate  125  to open to release the third dunnage piece  23  from the lower dunnage position, thereby placing the third dunnage piece. The method can include placing the third dunnage piece  23  onto the stack unit  10 .