Abstract:
The container handling device may include features useful for supporting a container (e.g., an open top rectangular bin) while the container is being filled, and supporting the container when tipping the container to empty contents of the container. The container handling device includes features that improve safe handling of the container when emptying. The container handling device also includes features that provide improved assembly and disassembly of various features for the purposes of, for example, manufacturing, shipping, replacing parts, and conducting maintenance.

Description:
BACKGROUND 
   1. Technical Field 
   The present invention generally relates to container handling devices, and more specifically relates to container handling devices for front-end loaders. 
   2. Related Art 
   Front-end loaders are commonly used to transport containers. Containers often need to be emptied while carried by the front-end loader. Attachment devices for front-end loaders are a convenient manner of emptying a container while the container is still carried by the front-end loader. There have been substantial efforts directed at improving various aspects of such attachment devices. 
   It is often advantageous to empty large, open-topped containers by tipping the container using the attachment device to let the contents fall out. While this is an effective means of emptying the container, this type of emptying may result in problems arising from operator error, non-uniform size containers, or erratic handling of the container if the container is not properly handled by the attachment device. If the container is not properly handled, operators in close proximity to the front-end loader are endangered and there is a potential for damage to surrounding equipment and the contents of the container if the container falls off the attachment device. The likelihood of a container falling off an attachment device is increased if the handling operation of the attachment device is not smooth and consistent. 
   Furthermore, the need for an attachment device to be capable of handling different sized containers necessitates the attachment device contain a number of components, many of which are sizable. Some attachment devices integrate components with permanent connections, such as welding, that can result in disadvantages related to manufacturing, transport, and maintenance of the attachment device. For example, a permanently integrated attachment device must be painted or finished as a single unit, which requires a large facility. Transporting a permanently integrated attachment device provides similar challenges since large structures are unwieldy to handle and require a vehicle with a large cargo capacity. Even after manufacturing and transporting a permanently integrated attachment device, maintaining the attachment device can be difficult because replacing a component will either require a difficult process or necessitate acquiring an entirely new attachment device. 
   SUMMARY 
   The present invention generally relates to container handling devices, and more specifically relates to container handling devices for front-end loaders. The container handling device may include features useful for supporting a container (e.g., an open top rectangular bin) while the container is being filled, and supporting the container when tipping the container to empty contents of the container. The container handling device includes features that improve safe handling of the container when emptying. The container handling device also includes features that provide improved assembly and disassembly of various features for the purposes of, for example, manufacturing, shipping, replacing parts, and conducting maintenance. 
   One aspect of the invention relates to a container holding device for use with a front-end loader, wherein the device includes a base, a container frame, first and second actuators, and first and second bottom container retainers. The base frame includes first and second rails, a cross-support coupled between the first ends of the first and second rails. The base frame is configured for attachment to the front-end loader. The container frame includes first and second horizontal arms, first and second vertical arms, and first and second top container retainers. The top container retainers extend from the vertical arms in a direction generally parallel to the horizontal arms. The horizontal arms are pivotally coupled to the base frame at second ends of the first and second rails with first and second coupling members. The coupling members are adjustable to provide detachment of the container frame from the base frame, and the top bin retainers extend from ends of the vertical arms in a direction parallel to the horizontal arms. The first actuator is coupled between the base frame and the container frame and is configured to move the container frame relative to the base frame a first distance. The second actuator is coupled between the base frame and the container frame and is configured to move the container frame relative to the base frame a second distance. The first and second bottom container retainers are adjustable between extended and retracted position, wherein in the extended position the container retainers restrict horizontal movement of a container supported on the first and second rails. 
   Another aspect of the invention relates to a container holding device for use with a front-end loader, wherein the device includes a base frame, a container frame, first and second actuators, and a bottom container retainer. The base frame includes first and second rails, a cross-support coupled between the first ends of the first and second rails, and an actuator support extending in a generally normal direction from cross-support. The base frame is configured for attachment to the front-end loader. The container frame includes first and second horizontal arms, first and second vertical arms extending from the horizontal arms, a top container retainer, and an actuator engagement member. The actuator engagement member includes a track structure and the horizontal arms is pivotally coupled to the base frame at second ends of the first and second rails with first and second coupling members. The top container retainer extends from one of the vertical arms in a direction parallel to the horizontal arms and is arranged to resist movement of a container supported on the horizontal arms in a direction perpendicular to the horizontal arms. The first actuator is coupled to and extends parallel with the actuator support. The first actuator includes a roller positioned on a free end thereof that is configured to fit within the track structure, wherein extension of the first actuator moves the container frame through pivotal motion relative to the base frame. The second actuator is coupled between the base frame and the container frame and configured to move the container frame through further pivotal motion relative to the base frame. The bottom container retainer includes an elongate actuating arm and an engagement arm coupled to the actuating arm. The actuating arm is mounted to the container frame and configured to rotatably adjust the engagement arm into an engagement position to resist movement of the container relative to the horizontal arms in a direction parallel to the horizontal arms. 
   A further aspect of the invention relates to a method of unloading a container using a container holding device that is attached to a front-end loader. The holding device includes a base frame, a container frame, first and second actuators, at least one bottom container retainer, and at least one top container retainer. The base frame includes first and second rails and is configured for attachment to the front-end loader. The container frame includes first and second horizontal arms and at least one vertical arm. The method includes supporting the container on the first and second horizontal rails, rotating the bottom container retainer into a raised position to engage a bottom front edge of the container, and coupling the at least one top container retainer to the at least one vertical arm and adjusting a position of the at least one top container retainer to engage a top rear edge of the container. The method further includes coupling the first and second horizontal arms to respective first and second rails with a pivot connection, the pivot connection being removable to provide detachment of the horizontal arms from the rails, actuating the first actuator to initiate rotation of the container frame relative to the base frame, and actuating the second actuator after actuating the first actuator to further rotate the container frame relative to the base frame until contents of the container unload from the container by gravity forces. 
   The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The detailed description that follow more particularly exemplified embodiments of the invention. While certain embodiments will be illustrated and described, the invention is not limited to use in such embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may be more completely understood in consideration of the following detailed description of various embodiments in the invention and in connection with accompanying drawings, in which: 
       FIG. 1  is a top rear perspective view of an example attachment device according to the invention, wherein the device is in a lowered position; 
       FIG. 2  is a side view of the attachment device shown in  FIG. 1 ; 
       FIG. 3  is a rear view of the attachment device shown in  FIG. 1 ; 
       FIG. 4  is a top rear perspective view of the attachment device shown in  FIG. 1 , wherein the device is in a raised position; 
       FIG. 5  is a side view of the attachment device shown in  FIG. 4 ; 
       FIG. 6  is an exploded perspective view of one of the container retainers shown in  FIGS. 1-5 ; 
       FIG. 7  is an exploded perspective view of portions of the container frame and base frame shown in  FIGS. 1-5  and the pivotal attachment of those frame members to each other; and 
       FIG. 8  is a perspective view of the attachment device shown in  FIG. 1  in use with a front-end loader. 
   

   While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
   DETAILED DESCRIPTION 
   The present invention relates to attachment devices for handling containers. The attachment devices are particularly useful for carrying containers using a front-end loader. The attachment devices include a first frame member that is mounted to the horizontal arms of a front-end loader, and a second frame member that can rotate with respect to the first frame member. As will be described below, the attachment devices further include mechanisms for rotating the second frame member relative to the first frame member, and mechanisms for securing the container to the attachment device before, during, and after rotation of the second frame member relative to the first frame member. The following detailed description, with reference to  FIGS. 1-8 , describes example container handling devices for a front-end loader. 
     FIGS. 1-3  illustrate a container handling device  10  in a closed, non-rotated position.  FIGS. 4 and 5  illustrate the device  10  in an open, rotated position. Container handling device  10  includes a base frame  12 , which is configured to engage the lift arms of a front-end loader that extend generally horizontally from the front side of the front-end loader (e.g., see lift arms  202  of loader  200  shown in  FIG. 8 ). A container frame  14  is connected to base frame  12  and can rotate with respect to base frame  12 . The device  10  can hold and support a container such as, for example, box B shown in  FIGS. 2 and 5 . 
   A first actuator  16  is shown connected to base frame  12  in a retracted state. The first actuator  16  is positioned between the base frame  12  and the container frame  14  so that extension of the first actuator  16  initiates rotation of the container frame  14  with respect to the base frame  12 . The first actuator  16  may be, for example, a mechanical actuator, hydraulic actuator, pneumatic actuator, or of any other type of actuator capable of supplying sufficient force to initiate rotation of container frame  14  with respect to base frame  12 . The first actuator  16  is arranged at an angle β relative to a plane that is arranged perpendicular to the base frame  12 . The angle beta is typically in the range of about 5° to about 15°. 
   A second actuator  18  and a third actuator  20  are shown positioned between the base frame  12  and the container frame  14  in a retracted state. The second and third actuators  18 ,  20  can be extended to further rotate the container frame  14  with respect to the base frame  12 . The second and third actuators  18 ,  20  may be, for example, mechanical actuators, electric actuators, hydraulic actuators, pneumatic actuators, or of any other type of actuators capable of supplying sufficient force to rotate container frame  14  with respect to base frame  12 . 
   A first bottom container retainer  22  and a second bottom container retainer  23  are connected to container frame  14 . A container is generally supported on the container frame  14 . As the container frame  14  rotates with respect to the base frame  12 , a container generally supported by the container frame  14  is motivated by gravity to slide off of the container frame  14 . The first and second bottom container retainers  22 ,  23  help prevent a container from sliding off the container frame  14  as the container frame  14  rotates with respect to the base frame  12 . 
   A first top container retainer  24  is connected to the container frame  14 . A first insert container retainer  120  is connected to the first top container retainer  24  and includes a retaining peg  124  that extends substantially perpendicular to the first top container retainer  24 . A second top container retainer  26  is connected to the container frame  14 . A second insert container retainer  122  is connected to the second top container retainer  26  and includes a retaining peg  126  that extends substantially perpendicular to the second top container retainer  26 . 
   A container is generally supported by the container frame  14 . As the container frame  14  rotates with respect to the base frame  12 , the first and second bottom container retainers  22 ,  23  help prevent a container from sliding off of the container frame  14 . As the container frame  14  continues to rotate with respect to the base frame  12 , a container will be motivated by gravity to tip off the container frame  14 . The first and second top container retainers  24 ,  26  help prevent a container from tipping off of the container frame  14  as the container frame  14  rotates with respect to the base frame  12 . 
   Container handling device  10  is capable of handling open-top containers. The retaining pegs  124 ,  126  of the first and second insert container retainers,  120 ,  122  can extend into the open top of an open-top container to help prevent a container from both sliding and tipping off of the container frame  14  as the container frame  14  rotates with respect to the base frame  12 . 
   An actuator controller  28  is attached to the base frame  12 . The actuator controller  28  is capable of controlling the first actuator  16 , the second actuator  18 , the third actuator  20 , or any combination thereof. More than one actuator controller  28  may be used to control the actuators  16 ,  18 ,  20 ,  22 , separately or in any combination thereof. The actuator controller  28  may be of any type such as, for example, a hydraulic controller, a pneumatic controller, or an electronic controller. 
   The base frame  12  includes a first rail  30 , a second rail  32 , first and second ends  33 ,  35 , a cross-support  34 , and an actuator support  36 . The first and second rails  30 ,  32  are substantially parallel to each other and spaced apart to allow the base frame  12  to be engaged by the lifting arms of a front-end loader (e.g., see lift arms  202  of loader  200  shown in  FIG. 8 ). The arms of the front-end loader engage the rails  30 ,  32  via fork channels  38  defined at the first end  33  of each of the rails  30 ,  32 . 
   The cross-support  34  connects the first rail  30  and the second rail  32  near the first end  33 . The actuator support  36  is connected to the base frame  12  and supports the first actuator  16 . The actuator support  36  extends from the base frame  12  at an angle of about 75° to about 90°. 
   A fork attachment bracket  40  is attached to the base frame  12  near the first end  33 . Fork attachment  40  is substantially parallel to the first and second rails  30 ,  32  and extends past the first end  33 . Fork attachment bracket  40  provides a structure for anchoring container handling device  10  to a front-end loader to help prevent container handling device  10  from sliding of the lift arms of the front-end loader. A pair of anchoring bolts  131  may be used to secure the brackets  40  to the front-end loader. Securing pins  130  may be secured to the bolts  131  after they have been inserted into the brackets  40  to help retain the bolts  131  in place. 
   The first and second rails  30 ,  32  have a base frame aperture  42  near the second end  35 . The aperture  42  may be defined in the rails  30 ,  32  (e.g., through sidewalls of the rails—not shown), or defined by a cylindrical sleeve  43  mounted to the rails  30 ,  32  using, for example, a mounting plate  45  (see the exploded view shown in  FIG. 7 ). Additional sleeve sections (e.g., sleeve  51 ) may be used depending on the size and type of connector used to couple the rails  30 ,  32  to the container frame  14 . Typically, the base frame aperture  42  coincides with a axis about which the container frame  14  rotates with respect to the base frame  12 . The pivotal connection of the rails  30 ,  32  to the container frame  14  via the frame apertures  42  is discussed below. 
   Each rails  30 ,  32  includes an engagement arm recess  44  formed in a top primary surface thereof near the second end  35 . The recess  44  is sized to retain engagement arms of the first and second bottom container retainers  22 ,  23  in a retracted position that is flush mounted with the top primary surface of the rails  30 ,  32 . A similar recess  44  may be formed in container frame  14  alone or in or both the base and container frames  12 ,  14 . 
   The container frame  14  includes a first and second horizontal arms  50 ,  52 , a first and second vertical arms  54 ,  56 , a first, second and third container frame cross-supports  58 ,  60 ,  62 , and an actuator engagement member  64 . The first and second horizontal arms  50 ,  52  are substantially parallel to each other and configured to engage the top primary surface of the first and second rails  30 ,  32 , respectively. The arms  50 ,  52  also define a top primary surface upon which a container retained by the container handling device  10  is supported. 
   The first and second vertical arms  54 ,  56  are extend vertically in a perpendicular direction from the first and second horizontal arms  50 ,  52 , respectively. The first and second verticals arms  54 ,  56  also extend substantially parallel to each other and are configured to mount the first and second top container retainers  24 ,  26  in a position across a top of a container held by the container handling device  10 . 
   The first container frame cross-support  58  extends horizontally between the first and second vertical arms  54 ,  56 . The first container frame cross-support  58  is positioned at a distance spaced vertically from base frame cross-support  34  (e.g., a spaced distance slightly greater than the retracted length of first actuator  16 ). The second container frame cross-support  60  extends horizontally between the first and second vertical arms  54 ,  56  near the attachment point of first and second vertical arms  54 ,  56  with the respective first and second horizontal arms  50 ,  52 . The third container frame cross-support  62  extends horizontally between the first and second horizontal arms  50 ,  52 . The third container frame cross-support  62  is positioned at a distance spaced horizontally from the base frame cross-support  34  (e.g., a distance slightly greater than the retracted length of second and third actuators  18 ,  20 ). 
   The actuator engagement member  64  extends horizontally from the first container frame cross-support  58  in a direction towards the first actuator  16 . The actuator engagement member  64  extends into a position generally vertically above the first actuator  16  and is in a path of extension of the first actuator  16 . The engagement member  64  includes a track  65  attached to a bottom side thereof for engagement with the first actuator  16  when the first actuator  16  extends. The track  65  helps the first actuator  16  maintain contact with the engagement member  64  as the first actuator  16  extends, thereby rotating the container frame  14  relative to the base frame  12 . 
   The first and second horizontal arms  50 ,  52  each include a container frame aperture  66  positioned, for example, between opposing ends of the arms  50 ,  52 . The container frame aperture  66  is arranged coaxially with the base frame aperture  42 . The apertures  42 ,  66  are sized to receive a coupling member  67 . The coupling member  67  may be, for example, a pin, bolt, rod, or any hardware sufficient to couple the apertures  42 ,  66  together to allow the container frame  14  to rotate with respect to the base frame  12 .  FIG. 7  illustrates member  67  as a pin having recesses  47  formed in opposing ends. The recesses  47  are sized to receive caps  49  that provide a more secure attachment and retention of the member  67  within the aperture  42  defined by sleeve  43 . 
   In some embodiments, the member  67  may have other configurations that provide desired pivotal connection between the bases  12 ,  14 . For example, the member  67  may include a bolt configuration with a fixed head on one end and external threads on an opposing end that is configured to receive a removable nut. 
   The coupling member  67  is preferably configured for relatively easy removal from the apertures  42 ,  66  to provide disassembly of the frames  14 ,  16  from each other. For example, by removing one or more of the caps  49 , the member  67  can be removed so that the base frame  12  and container frame  14  are separable. Easy disassembly may also provide advantages related to replacement and maintenance of the member  67  or other features associated with the pivotal connection between the bases  12 ,  14 . 
   The first actuator  16  includes a first actuator fixed component  70  and a first actuator extending component  72 . The first actuator fixed component  70  is connected to the actuator support  36 . The first actuator extending component  72  includes a roller  78  mounted on one end that engages the track  65 . The first actuator extending component  72  can extend from the first actuator fixed component  70  to initiate rotation of the container frame  14  with respect to the base frame  12 . The roller  78  rolls along the track  65  as the first actuator  16  extends, causing the container frame  14  to begin rotating relative to the base frame  12 . The use of the roller  78  as a contact surface between the first actuator  16  and the container frame  14  provides a reduced friction contact and a smoother actuation of the container frame  14  through its rotation motion relative to the base frame  12 . The track  65  and the roller  78  help to ensure that the initial rotation of the container frame  14  with respect to the base frame  12  is controlled and consistent. 
   The first actuator  16  is secured to the actuator support  36  by a bracket  80  and an actuator coupler  82 . The actuator coupler  82  may be, for example, a pin, bolt, rod, or any hardware sufficient to connect the first actuator  16  to the actuator support  36 . The actuator coupler  82  is preferably removable to allow the first actuator  16  to be easily separated from the actuator support  36 , for example, when the first actuator  16  must be repaired or replaced. 
   A container frame bracket  88  may be used to connect the second and third actuators  18 ,  20  to the third container frame cross-support  62 . The container frame bracket  88  may be any hardware configured for attachment of the first and second actuators  18 ,  20  to the cross-support  62  while permitting rotational movement of the actuators  18 ,  20  relative to the cross-support  62 . A removable pin may be used to couple the actuators  18 ,  20  to the cross-support  62  thereby providing easy detachment of the actuators  18 ,  20  for maintenance or replacement purposes. 
   A base frame bracket  90  may be used to connect the second and third actuators  18 ,  20  to the base frame cross-support  34 . The base frame bracket  90  may be any hardware configured for attachment of the first and second actuators  18 ,  20  to the cross-support  34  while permitting rotational movement of the actuators  18 ,  20  relative to the cross-support  34 . A removable pin may be used to couple the actuators  18 ,  20  to the cross-support  34  thereby providing easy detachment of the actuators  18 ,  20  for maintenance or replacement purposes. 
   The first and second top container retainers  24 ,  26  each include an insert leg  92  and an engagement leg  94 . The insert leg  92  of the first container retainer  24  is parallel with and engages the first vertical arm  54 . The insert leg  92  of the second container retainer  26  is parallel with and engages the second vertical arm  56 . The engagement leg  94  is substantially perpendicular to the insert leg  92  and substantially parallel with the first and second horizontal arms  50 ,  52 . 
   The insert leg  92  has at least one insert leg adjustment aperture  96 . The insert leg  92  may have any number of insert leg adjustment apertures  96  to provide the desired amount of adjustment of the top container retainers  24 ,  26  relative to the vertical arms  54 ,  56 . The first and second vertical arms  54 ,  56  each include a vertical arm adjustment aperture  97 . An adjustment coupler  98  may be inserted through the insert leg adjustment aperture  96  to the vertical arm adjustment aperture  97  to provide a connection and engagement between the container retainers  24 ,  26  and the container frame  14 . A pin  132  may be used to retain the coupler  98  in the apertures  96 ,  97 . The adjustment coupler  98  may be, for example, a pin, bolt, rod, or any hardware that is removable from the apertures  96 ,  97  and replaceable therein for a height adjustment of the container retainers  24 ,  26  relative to the container frame  14 . The distance from the first and second horizontal arms  50 ,  52  to the engagement leg  94  can be adjusted by changing which insert leg adjustment aperture  96  that adjustment coupler  98  is engaged with. 
   The first and second bottom container retainers  22 ,  23  each include an actuating arm  100 , a spring retainer  101 , a counterweight  102 , a first engagement arm  104 , a fastener  106 , a first stop  108 , and a first cylinder  110  (see  FIG. 6  for an exploded view of an example bottom container retainer  22 ,  23 ). The actuating arm  100  is coupled to the container frame  14  in an orientation substantially parallel with the first horizontal arm  50  and can rotate about an axis substantially parallel to the first horizontal arm  50 . The counterweight  102  is attached to an end of the actuating arm  100  adjacent to the first end  33  of the base frame  12 . An opposing end of the actuating arm  100  as well as the first engagement arm  104  and the first stop  108  are attached to the first cylinder  110 . In some embodiments, the first engagement arm  104 , first stop  108 , and first cylinder  110  may be integrally formed as a single piece using, for example, casting or molding techniques. In other embodiments, some or all of the first engagement arm  104 , the first stop  108 , and the first cylinder  110  may be separate pieces that are coupled together during assembly of the container handling device  10  using, for example, fasteners, welding, etc. 
   A fastener  106  (e.g., a removable pin) may be used to detachably connect the first cylinder  110  to the actuating arm  100 . Bottom retainers  22 ,  23  may include additional fasteners or other structures that provide disassembly of various parts or subassemblies of the retainers  22 ,  23  for purposes of, for example, maintenance or replacement of parts. The ability to replace or repair individual portions of the bottom retainers  22 ,  23  separate from the entire assembly can provide cost and time efficiencies that may not be possible if the entire assembly  22 ,  23  has to be removed and/or replaced for every repair or maintenance required. For example, removing fastener  106  can provide removal and replacement of the arm  104  without disconnecting or removing the other parts  100 ,  102  from the frame  14 . 
   The first bottom container retainer  22  maintains a closed position when first engagement arm  104  is positioned in the engagement recess  44 . The counterweight  102  provides a rotational force on the actuating arm  100  that biases the first bottom container retainer  22  into the closed position when the container holding device  10  is in the closed position. The retainer spring  101  helps to bias the first engagement arm  104  into a raised position when the container holding device  10  is in the open position (see  FIGS. 4-5 ). The biasing forces of spring  101  may be especially useful if the container B is not in contact with the  104  as the device  10  moves between the open and closed positions. 
   The retainer spring  101  may be a compression, extension or any other desired style of spring depending the position and orientation of the spring  101 . The retainer spring  101  may be positioned at alternative locations besides adjacent to the counterweight  102 . For example, the spring  101 , or some other type of biasing member, may be positioned along the length of the actuating arm  100  and provide a rotational force on the arm  100 . 
   The second bottom container retainer  23  includes an actuating arm  100 , a counterweight  102 , a first engagement arm  104 , a fastener  106 , a first stop  108 , and a first cylinder  110 . The actuating arm  100  is coupled to the container frame  14  in an orientation substantially parallel with the second horizontal leg  52  and can rotate about an axis substantially parallel to the second horizontal leg  52 . The counterweight  102  is attached to an end of the actuating arm  100  adjacent to the first end  33  of the base frame  12 . An opposing end of the actuating arm  100  as well as the first engagement arm  104  and the first stop  108  are attached to the first cylinder  110 . In some embodiments, the first engagement arm  104 , the first stop  108 , and the first cylinder  110  may be integrally formed as a single piece using, for example, casting or molding techniques. In other embodiments, the first engagement arm  104 , first stop  108 , and first cylinder  110  may be separate pieces that are couple together during assembly of the container handling device  10  using, for example, fasteners, welding, etc. The fastener  106  is a removable pin that detachably connects the first cylinder  110  to the actuating arm  100 . 
   The second bottom container retainer  23  maintains a closed position when first engagement arm  104  is positioned in the engagement recess  44 . The counterweight  102  provides a rotational force on the actuating arm  100  that biases the second bottom container retainer  23  into the closed position when the container holding device  10  is in the closed position. 
     FIGS. 4 and 5  illustrate the container holding device  10  in a partially open position after initial rotation provided by extension of the first actuator  16 . After initial rotation by the first actuator  16 , the roller  78  no longer engages with track  65  and the second and third actuators  18 ,  20  control further rotation of the container frame  14  relative to the base frame  12 . 
   The first bottom container retainer  22  rotates into an open position when the first engagement arm  104  is substantially perpendicular to first horizontal arm  50 . As the container frame  14  rotates with respect to the base frame  12 , the rotated position of the counterweight  102  changes thereby providing a different rotational force that biases the first engagement arm  104  into the open position shown in  FIGS. 4 and 5 . The second bottom container retainer  23  rotates into an open position when the first engagement arm  104  is substantially perpendicular to second horizontal arm  52 . As the container frame  14  rotates with respect to the base frame  12 , the rotated position of the counterweight  102  changes thereby providing a different rotational force that biases the first engagement arm  104  into the open position shown in  FIGS. 4 and 5 . 
   While the counterweights  102  function effectively to ensure that the engagement arms  104  are always raised with the frame  14  rotates open, other mechanisms and configurations may be used in place of the counterweights  102  and provide the same or similar result. 
   The container holding device  10  may include several safety measures that can improve the overall safety of the device  10 . The first and second bottom container retainers  22 ,  23  help prevent a container from sliding off of the container frame  14  as the container frame  14  rotates relative to the base frame  12  by providing a physical stop along a bottom front edge of the container. Additionally, the retaining pegs  124 ,  126  of the first and second insert container retainers  120 ,  122  can extend into an open top container to help prevent a container from sliding off container frame  14  as container frame  14  rotates with respect to base frame  12  by providing a physical stop along a back top interior edge of the container. Furthermore, the first and second top container retainers  24 ,  26  help prevent a container from tipping off of the container frame  14  as the container frame  14  rotates relative to the base frame  12  by providing a physical stop along a top back edge of the container. The height of the first and second top container retainers  24 ,  26  is adjustable to help of secure a top rear edge of a container for containers of various sizes held by the container frame  14 . Additionally, the retaining pegs  124 ,  126  of the first and second insert container retainer,  120 ,  122  extend into an open top container to help prevent a container from tipping off container frame  14  as container frame  14  rotates with respect to base frame  12  by providing a physical stop along a top back edge of the container. 
   Controlled and consistent handling of containers by device  10  also improves overall safety. The use of the track  65  and the roller  78  helps to ensure that the initial rotation of the container frame  14  with respect to the base frame  12  is controlled and consistent. During initial rotation, the roller  78  maintains contact with the track  65  as it rolls. The rolling action helps prevent the erratic movements that may be cause by surfaces sliding against one another. 
   The container holding device  10  may include additional first and second insert container retainers  120 ,  122  that are coupled to container retainers  24 ,  26 , respectively (see  FIGS. 1 ,  2 ,  4  and  5 ). The first and second insert container retainers  120 ,  122  include retaining pegs  124 ,  126  that extend in a direction toward the horizontal arms  50 ,  52  of the container frame  14 . The first and second insert container retainers  120 ,  122  may be configured to fit into or fit over an exposed end of the container retainers  24 ,  26  and secured to the retainers  24 ,  26  with a connecting member such as, for example, a connecting pin (not shown). 
   In use, the first and second insert container retainers  120 ,  122  may be coupled to the retainers  24 ,  26  after the retainers  24 ,  26  have been adjusted into a desired position relative to the vertical arms  54 ,  56  of the frame  14  (e.g., the retainers  24 ,  26  have been adjusted vertically into contact with a top surface of a container held in frame  14 ). The first and second insert container retainers  120 ,  122  may alternatively be secured to the retainers  24 ,  26  before the retainers  24 ,  26  are connected or positioned relative to the vertical arms  54 ,  56 . 
   By connecting the first and second insert container retainers  120 ,  122  to retainers  24 ,  26 , the retaining pegs  124 ,  126  typically can extend into an interior of a container held by the frame  14 . The arms can then provide additional safety for the device  10  by increasing its ability to retain a container when the container frame  14  rotates relative to the base frame  12  to empty the container. 
   Separability of components can simplify manufacturing, transportation, and maintenance of the container holding device  10  or sub-assemblies of the device  10 . Separation and easy disassembly permits components to be constructed and finish (e.g., painted, etc.) as separate pieces, which simplifies manufacturing and assembly of the container handling device  10 . Constructing an integrated device requires welding or similar operation that is more complex and expensive than using less permanent forms of assembly, such as fasteners. Also, constructing an integrated device using welding or similar operation is more difficult than using less permanent forms of assembly in the case of an error or desired modification. Finishing an integrated device is difficult for large devices since painting, chemically treating, or similar operation would require a facility at least as large as the device. Disassembling a device prior to finishing requires a smaller facility. Also, integrates devices cannot be finished prior to integration because paint, chemical treatment, or similar finish may interfere with welding or similar process. Separation and easy disassembly simplifies manufacturing and assembly of the container handling device  10 . 
   Separation of component also allows components simplifies shipping and handling, simplifying transportation. Shipping an integrated device requires a shipping method with a large cargo area. Individual pieces can be packed tighter and shipped with smaller area requirements. Also, handling an integrated device may require extra equipment when the integrated device is too large or unwieldy to be handled by hand. Individual pieces are more easily carried by hand. Separation of component simplifies transportation. 
     FIG. 8  illustrates an example front-end loader  200  for use with the container handling device  10 . The loader  200  includes a pair of lift arms  202  that engage the device  10  and provide lifting of the device  10  vertically. Other types of loaders besides the front-end, fork-lift style loader  200  could be used with the container handling device  10  to provide the lifting and moving features desired to provide proper unloading of a container held by the device  10 . 
   Additionally, separation allows components to be easily replaced, which simplifies maintenance. Repairing an integrated device may require the entire device to be replaced if a single component cannot be replaced. Even if a piece that is attached by welding or similar operation can be removed, the removal process can leave the device weakened at the point of removal. Less permanent forms of assembly allow a component to be removed and replaced without damaging the device. Separation simplifies maintenance 
   The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.