Abstract:
To collect refuse, a portable material container gripper is mounted to lift arms of a refuse collection truck. The portable material container gripper is easily mounted to the lift arms by inserting a tube around the lift arms and locking it in place with a bar passing through an opening in the tube. The portable material container gripper includes a clamp that clamps around a horizontal bar on a refuse or material container to hold the refuse or material container in place while it is dumped into the bed of the refuse collection truck by the lift arms.

Description:
BACKGROUND OF THE INVENTION 
     Material collection apparatus including a truck with a front or side loader are well known, particularly for refuse collection. One class of refuse collection apparatuses and methods utilizes special containers which are filled by the customers of a refuse collection company. Front loading or side loading vehicles go from customer to customer and empty the containers into the truck bed. 
     In one prior art material collector of this class, multiple part units are mounted permanently to a vehicle. These multipart units grip material containers or slide into pockets built into the material containers. Generally, the material containers are trash containers. Prior art systems of this type are disclosed in U.S. Pat. Nos. 7,210,890 and 5,639,201. These systems have a disadvantage in that if either the vehicle or the multipart unit for gripping the containers is not operable, then neither the vehicle nor the multipart gripping apparatus are usable. The only substitute is another vehicle containing the apparatus for picking up the material containers. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the invention to provide a novel trash can gripper. 
     It is a still further object of the invention to provide a novel method of collecting material. 
     It is a still further object of the invention to provide a novel method of emptying containers. 
     It is a still further object of the invention to provide a novel material collection system. 
     It is a still further object of the invention to provide a novel container dumping system. 
     It is a still further object of the invention to provide a portable container gripper which may be carried to a vehicle and used by the vehicle to grip a series of containers, one after the other. 
     It is a still further object of the invention to provide a material collection system which may quickly move from location to location to collect material. 
     It is a still further object of the invention to provide a material dumping system which has a very short time duration dumping cycle. 
     It is a still further object of the invention to provide a container gripper for a collection system which is easily connected and disconnected from vehicles and may attach a series of containers to the vehicles to which it is attached. 
     It is a still further object of the invention to provide a container gripper which can be used for different types of containers such as commercial heavy containers or lighter containers. 
     It is a still further object of the invention to provide a material collection system which operates from the front of a vehicle to dump material into a bed of the vehicle in a process that permits the operator of the vehicle to see the material that is being dumped. 
     In accordance with the above and further objects of the invention, a lightweight gripper is provided. The lightweight gripper can be carried by a single person and mounted to a lift arm of a vehicle by one person in a simple operation. The gripper contains an easily actuated mechanism for gripping containers that are equipped with a standard gripping bar. The gripper is actuated with a lever operated by a single person to grip a container. The container can be locked in place with a simple locking mechanism. After the container is dumped by the vehicle, it can be easily unlocked and the gripper used for another container. 
     From the above description, it can be understood that the collection system of this invention has several advantages, such as: (1) it has a very short cycle time for emptying a container of less than ten seconds long, such as only a few seconds long; (2) the gripper is portable and may be utilized on many different vehicles; (3) the gripper can be carried by one person, mounted to a lift arm of a vehicle by one person and may grip a can by a simple lever operation by one person; and (4) even though the gripper is portable and easily used, it is strong and durable and may be economically manufactured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above noted and above features of the invention will be better understood from the following detailed description, in which: 
         FIG. 1  is a schematic drawing showing the manner in which the portable material container gripper can be used in conjunction with a vehicle and a number of collection sites; 
         FIG. 2  is a perspective view illustrating the manner in which the portable gripper may be mounted to a lift arm; 
         FIG. 3  is a perspective view of the portable gripper of this invention from one angle; 
         FIG. 4  is a perspective view of the portable gripper taken from another angle; 
         FIG. 5  is a perspective view of one part of the portable gripper of  FIGS. 3 and 4 ; 
         FIG. 6  is an elevational view of another part of the gripper of  FIGS. 3 and 4 ; 
         FIG. 7  is a side view of the portion of the gripper shown in  FIG. 6 ; 
         FIG. 8  is a perspective view of another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 9  is a side view of the part shown in  FIG. 8 ; 
         FIG. 10  is a perspective view showing the attachment of the gripper of this invention to the lift arm of a vehicle; 
         FIG. 11  is a perspective view showing the manner in which the gripper of  FIG. 10  is fastened and locked firmly in place on a lift arm; 
         FIG. 12  is a perspective view of still another part of the gripper of  FIGS. 3 and 4 ; 
         FIG. 13  is a perspective view from another angle of the part of  FIG. 12 ; 
         FIG. 14  is a perspective view of still another part of the gripper of  FIGS. 3 and 4 ; 
         FIG. 15  is a perspective view of still another part of the gripper of  FIGS. 3 and 4 ; 
         FIG. 16  is a perspective view of an operator connecting a material handling container to the gripper of  FIGS. 3 and 4  while it is fastened to the lift arm of a vehicle; 
         FIG. 17  is a perspective view of an operator locking the container of  FIG. 16  in place to connect the container to the lift arm of a vehicle; 
         FIG. 18  is a perspective view showing another step of locking the container to the lift arm; 
         FIG. 19  is a side view of the gripper illustrating its construction in an open position; 
         FIG. 20  is a front view of the gripper of the  FIG. 19 ; 
         FIG. 21  is a perspective view of another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 22  is a perspective view of still another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 23  is a perspective view of still another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 24  is a perspective view of still another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 25  is a perspective view of still another portion of the gripper of  FIGS. 3 and 4 ; 
         FIG. 26  is a perspective view of still another portion of the gripper of  FIGS. 3 and 4 . 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , there is shown a schematic block diagram  10  illustrating the use of a material handling system in accordance with an embodiment of the invention. As shown in the block diagram  10  of  FIG. 1 , a plurality of residences  12 A- 12 D or other establishments with disposal needs and a plurality of material containers  14 A- 14 D located at respective ones of the residences or other establishments  12 A- 12 D are serviced by a vehicle  16  having the portable material container gripper attached to the vehicle. In this specification, the words “portable material container gripper” means a relatively lightweight fixture that can be attached both to a lift arm and to a waste container. It includes a movable arm mounting fixture and a material container clamp that permits mounting a material container to a lift arm of a vehicle for dumping material from the material container. In the preferred embodiment, the portable material container gripper weighs less than 150 pounds. 
     The vehicle with portable material container gripper attached  16  moves from locality to locality at the different ones of the residences  12 A- 12 D and empties the material containers  14 A- 14 D at each locality utilizing the material container gripper. In this process, the gripper is attached to a movable arm of the vehicle at each of the localities and it is also attached temporarily to a respective one of the containers  14 A- 14 D. The movable arm lifts the material container mounted to it by the portable material container gripper and empties it into a bed of the vehicle or other section adapted for storage and then returns the emptied material container to the ground where it may be easily removed by the operator. 
     The portable material container gripper may be attached to many different types of vehicles and to many types of containers but it is particularly adapted in the preferred embodiment for attachment to a lift arm of a front loader and to the type of container containing horizontal bars. Because it is reasonably lightweight and easily removed and attached to the lift arms, it may be used with any of the vehicles in a fleet of vehicles so that vehicles are not rendered useless because the attaching device is broken nor are the attaching devices unusable for lack of a vehicle. They are relatively inexpensive and spare grippers may be easily kept by an establishment. While a preferred embodiment will be disclosed in detail hereinafter, there are many variations which are possible and variations may be easily constructed for different types of material containers and different types of vehicles while maintaining the portability and easy removable and replaceable characteristics of the material container gripper. 
     In  FIG. 2 , there is shown a fragmentary simplified perspective view of a vehicle  16  with a portable material container gripper attached and an operator  18  for that vehicle. One such vehicle  30  which may be used as part of the combination of vehicle with portable material gripper attached is a front loader type vehicle having two lift arms one of which is shown at  22  with a portable material container gripper  20  mounted to it to form a combination vehicle and portable material gripper  16 . The portable material container gripper  20  has as some of its principal parts a combined spine-handle  24 , a movable lift arm mount  26  and a material container clamp  28 . While a combined spine-handle  24  is shown in the embodiment of  FIG. 2 , many different carrying mechanisms and central support and actuating mechanisms are possible. There are other variations which permit fitting to a lift arm and grasping a material container so that the material container may be moved by the lift arm for emptying the contents of the container but the embodiment shown in  FIG. 2  has special advantages such as being light and portable and very quick and easy to use. 
     Although the embodiment of portable material container gripper  20  shown in  FIG. 2  includes a combined spine-handle  24  that serves as an actuator to fasten the movable lift arm mount  26  and the material container clamp or hook  28  together to fasten a material container to the lift arm of a suitable vehicle such as a front loader, a separate actuator for fastening the material container clamp and movable lift arm mount is not necessary as each of these two may be separately actuated. Moreover, both may be a clamping device or any other type of fastener which can connect to one of a lift arm and a material container. They may be fastened directly to each other or may have intermediate support members or the like connecting the two. 
     In  FIGS. 3 and 4 , there are shown perspective views of the same portable material container gripper  20  from different angles each showing the combined spine-handle  24 , a movable lift arm mount  26  and a material container clamp or hook  28 . In the embodiment of  FIGS. 3 and 4 , the movable lift arm mount  26  is directly connected to the spine portion  40  of the combined spine-handle  24  such as by welding or the like and the combined spine-handle  24  is typically connected a portion of the material container clamp or hook  28 . However, the material container clamp could be rigidly fastened to the combined spine-handle and the movable lift arm mount pivotably mounted. 
     As best shown in  FIGS. 3 ,  4  and  5 , the movable lift arm mount  26  includes a principal holder sized and shaped to be fastened to a lift arm  22 . As best shown in  FIG. 5 , the principal holder in the preferred embodiment is a right regular parallelepiped  34 , sized to fit over a lift arm  22  (not shown in  FIGS. 3 ,  4  and  5 , shown in  FIG. 2 ). For this purpose, it has relatively elongated five inch vertical walls and two inch horizontal connecting walls. Cylindrical openings  36 A and  36 B pass through the vertical walls of the movable arm lift mount  26  in one corner and are sized to receive a horizontal locking bar described hereinafter. The horizontal locking bar is positioned to secure the movable lift arm mount  26  to the lift arm  22  ( FIG. 2 ). The movable lift arm mount  26  is fastened such as by welding to the combined spine-handle  24  ( FIGS. 3 and 4 ). With this arrangement, the principal holder  34  may slide over the lift arm  22  ( FIG. 2 ) and be secured in place by inserting the horizontal locking bar through the openings  36 A and  36 B as described in greater detail hereinafter. 
     In  FIGS. 3 ,  4 ,  6  and  7 , there is shown two perspective views, an elevational view and a side view respectively of the combined spine-handle  24  having a handle portion  38 , spine portion  40  and a pivotable end  42  (best shown in  FIGS. 6 and 7 ). The handle  38  includes a central opening sufficiently large to be grasped by the operator for carrying the portable material container gripper  20  or for pulling downwardly to pivot the material container clamp  28  to a closed position over a substantially horizontal bar on a material container. In the preferred embodiment, the spine portion  40  is 11 1/16 inches long and the entire combined spine-handle  24  is 16 inches long. It is formed of relatively flat material with a one-half inch thickness. The width of the spine portion  40  is two inches. The handle  38  is slightly bent for ease in grasping to form a five degrees angle from the plane of the spine portion  40 . The pivotable end  42  is welded to a tubular cylinder described hereinafter. A pivot pin passes through the central opening of the tubular cylinder to provide pivotable action for the closing of the material container clamp or hook  28  as described hereinafter. 
     In  FIGS. 8 and 9 , there is shown a perspective view and a side view respectively of the material container clamp or hook  28  having a substantially horizontal bar gripping section  46 , a pivot section  48  and an actuating section  50 . As best shown in  FIGS. 8 and 9 , the pivot section  48  contains an opening  52  sized to permit the end of the combined spine-handle  24  to move a sufficient distance about the pivot point to permit the bar gripping section  46  to grip a substantially horizontal bar on a material container as described further hereinafter. The actuating section  50  can be manipulated by hand for the purpose of pivoting the material container clamp or hook  28  to grip the material container to fasten it together with the lift arm  22  ( FIG. 2 ) of a vehicle  16  or to release it. 
     For this purpose, the bar gripping section  46  forms a hook shape on one side of the pivot section  48  while on the other side of the pivot section  48 , the actuating section  50  extends at an angle. 
     At the end of the actuating section  50 , there is a safety bracket  52  positioned to prevent gripping of the material container  14  unless the portable material container gripper  20  is correctly mounted to the lift arm  22  in a manner to be described hereinafter. In  FIG. 10 , there is shown a perspective view of the portable material container gripper  20  being positioned on the lift arm  22  by an operator  18  holding it by the handle portion  38  of the combined spine-handle  24 . As shown in this view, the actuating section  50  of the material container clamp or hook  28  is pulled downwardly, a horizontal lift arm locking bar  54  is pulled out, a vertical material container clamp locking rod  82  is pulled upwardly and a safety pin  68  ( FIG. 20 ) is pulled out. 
     In  FIG. 11 , there is shown a perspective view of the operator  18  pushing the horizontal lift-arm locking bar  54  into the interior of the movable lift arm mount  26  where it passes underneath the lift arm  22  to securely lock the lift arm  22  and the movable lift arm mount  26  together so that the portable material container gripper  20  may lift a heavy container upwardly and turn it upside down for dumping without the movable lift arm mount  26  being separated or moving relative to the lift arm  22  itself. 
     In  FIGS. 3 ,  4  and  12  there is shown a bottom gusset  58  formed as a prism with two narrower edges at right angles to each other connected by other angled sides between flat surfaces. The two sides at right angles to each other are welded respectively to the bottom of the movable lift arm mount  26  and the spine portion  40  of the combined spine-handle  24 . 
     In  FIGS. 3 ,  4  and  13 , there is shown a top gusset  60  also having two edges at right angles to each other between flat surfaces with one of the edges being welded to the spine portion  40  of the combined spine-handle  24  and the other to the top of the movable lift arm mount  26 . These two gussets  58  and  60  provide support on either side and are fastened firmly, preferably by welding to hold the spine portion  40  of the combined spine-handle  24  and movable lift arm mount  26  firmly together as a heavy material container  14  is moved from position to position imposing weight in different directions on the portable material container gripper  20 . 
     In  FIG. 14 , there is shown a perspective view of a retaining collar  62  having a cylindrical tubular portion  64 , a through slot  66  extending through the cylindrical tubular portion  64  and along the cylinder wall between wall to wall at one side and a pin  68  that fits in the opening of the retaining collar  62 . This collar  62  is welded over the opening  36 A or  36 B in the walls of the movable lift arm mount  26  and the retaining collar  62  and openings  36 A and  36 B are sized to accommodate the horizontal lift arm locking bar  54  which slides within the collar  62  and the openings  36 A and  36 B in the movable lift arm mount  26 . 
     In  FIG. 15 , there is shown a perspective view of the horizontal lift arm locking bar  54  having a solid cylindrical portion  70  and a cut away portion  72  in one side. The cut away portion  72  is sized to fit within the retaining collar  62  with the pin  68  in place whereas the horizontal lift arm locking bar  54  itself fits within the collar  62  but extends on either side of the pin  68 . With this arrangement, the horizontal lift arm locking bar  54  may be inserted within the collar  62  and through the aligned openings  36 A and  36 B ( FIG. 5 ) in the parallel walls of the movable lift arm mount  26  (FIGS,  2 ,  3  and  4 ). The pin  68  may then be inserted in the opening  66  to hold the horizontal lift arm locking bar  54  in place while permitting it to slide through the range of the cut away portion  72 . The cut away portion  72  is sufficiently large so that the horizontal lift arm locking bar  54  when moved outwardly permits the lift arm  22  to be inserted into the movable lift arm mount  26  ( FIGS. 2-5 ,  10  and  11 ) and when pushed in, fully holds the lift arm  22  securely in place within the movable lift arm mount  26 . 
     In the preferred embodiment, the movable lift arm mount  26  ( FIG. 5 ) includes side walls that are approximately five inches high jointed by horizontal walls approximately two inches long. The thickness of all four walls is approximately 3/16 of an inch. Parallel openings  36 A and  36 B ( FIG. 5 ) are centered 0.875 of an inch from a side edge and 0.815 of an inch from a bottom side. It has a diameter of 1.256 inches. The horizontal lift arm locking bar  54  ( FIG. 15 ) has an outside diameter of approximately 1.25 inches with a length a three inches. The cutaway portion is 2.75 inches long and is cut to a depth of 0.375 of an inch. Its outward start is 0.595 of an inch from one end. 
     In  FIG. 16 , there is shown a simplified fragmentary perspective view of an operator  18  positioning a waste container  14  with a substantially horizontal bar  74  in juxtaposition with a portable material container gripper  20 . As shown in  FIG. 16 , the waste material container  14  is positioned so that the substantially horizontal bar  74  is within the material container clamp or hook  28  with the movable lift arm mount  26  mounted on the lift arm  22 . The material container clamp or hook  28  is positioned downwardly about the pivotal end  42  of the portable material container gripper  20 . In this specification, the term “substantially horizontal bar” means an elongated member attached to a material or waste container  14  and sized to fit within a material container clamp or hook  28  of a portable material container gripper  20 . The largest distance perpendicular to its longitudinal axis (diameter if it is cylindrical) is less than 6 inches. It is between a horizontal position and a position less than 40 degrees from the horizontal. Horizontal is a direction parallel to the material container&#39;s bottom 
     As shown in  FIGS. 2-4 ,  10 ,  11  and  16 , the portable material container gripper  20  includes a locking bar  76 , a locking tube  78 , a ball knob  80 , a locking rod  82 , locking rod sleeve  84  and a helical spring  86 . The locking bar  76  is mounted to the knob  80  by the locking rod  82 . The bar, rod and knob  80  are biased upwardly by the helical compression spring  86  that is mounted around the sleeve  84  between the top of a parallelepiped shaped locking tube  78  and the knob  80  so that the locking bar  76  is biased upwardly. The locking tube  78  is shaped as a parallelepiped tube with a locking tube cap  96  at its top to support the end of the spring  86 . In the position in  FIG. 16 , the knob  80  and locking tube  78  are positioned upwardly and the vertical material container clamp locking bar  92  is positioned within the locking tube  78 . 
     In  FIG. 17 , there is shown a fragmentary perspective view of an operator  18  pulling upwardly on the end of the material clamp or hook  28  to cause it to pivot about the pivotal end  42  in the pivot section  48  to cause the bar gripping section  46  to grip the substantially horizontal bar  74  of the material container  14  and thus enable the portable material container gripper  20  to mount the material container  14  to the lift arm  22  of the vehicle  16  ( FIG. 2 ). With this arrangement, an operator can quickly connect the substantially horizontal bar of the material container  14  to the movable lift arm mount  26  of the portable material container gripper  20  so that it is fastened thereon. 
     In  FIG. 18 , there is shown a fragmentary view of an operator  18  pushing downwardly on the knob  80  of the locking rod  82  with the safety bracket  52  over the lift arm locking bar  54 . With this arrangement, the clamp  28  cannot be closed about the substantially horizontal bar  74  of the material container  14  unless the lift arm locking bar  54  has been depressed to secure the movable lift arm mount  26  to the lift arm  22  so that the material container  14  will not be loose on the lift arm  22 , thus providing a safety factor. When the lift arm locking bar  54  is depressed, a spring loaded safety pin  88  snaps in place through an opening in the vertical material container clamp locking bar  76  (not shown in  FIG. 18 , shown in  FIG. 4 ). This holds the locking bar downwardly to hold the bar gripping section  46  of the portable material container gripper  20  in its closed position about the substantially horizontal bar  74  of the material container  14 . 
     With this arrangement, independent double locks are provided for the movable lift arm mount  26  and the container clamp  28  to avoid accidents. In the specification, the language “independent lift arm and material container locks” means an arrangement in which a holding device for the lift arm  22  is held firmly in place about the lift arm  22  by a first device that must be manually removed before the holder  28  on the lift arm  22  is free to move and another device that must be manually removed from the material container  14  before the material container  14  is free to move with respect to the portable material container gripper  20 . 
     In  FIGS. 19 and 20 , there are shown respectively a side view and a front view of the portable material container gripper  20  showing the manner in which a lower pivot tube  92  in the pivot section  48  enables pivoting of the material container clamp or hook  28 . As best shown in  FIG. 20 , a pivot pin  94  is welded to the material container clamp or hook  28 . The pivot tube  92  is welded to the bottom of the spine portion  40  ( FIG. 6 ) at the pivotal end  42  of the combined spine-handle  24  to permit pivoting of the material container clamp or hook  28  with respect to the combined spine-handle  24 . 
     As best shown in  FIGS. 4 ,  19  and  20 , the locking rod  82  is threaded into the knob  80  and extends through the locking rod sleeve  84 . The helical compression spring  86  extends from the knob  80  to the cap  96  of the locking tube  78  to bias the knob  80 , rod and locking bar upwardly with the sleeve being shorter than the helical spring in its expanded state to limit movement downwardly of the vertical locking bar  76 . The locking rod  82  ( FIG. 17 ) extends into and is threaded into the locking bar  76 . The locking rod  82  is welded to the locking bar  76 . With this arrangement, when the locking bar  76  is moved downwardly by pressing on the knob  80 , the locking bar  76  locks the clamp  28  in place and is positively locked by a spring loaded safety pin  88 . When the spring loaded safety pin  88  is manually pulled out, the compression spring  86  moves the knob  80  and locking bar  78  upwardly so that the clamp  28  may be manually removed from the lift arm. 
     To receive the spring loaded safety pin  88  and maintain alignment between the locking bar  76  and locking rod  82 , the square locking bar  76  fits within the locking tube  78  with a close tolerance that permits movement upwardly and downwardly within the locking bar  76 . It includes an opening alignable with the opening in the locking tube  78  so that the spring loaded safety pin  88  is forced by its spring pressure through both the opening in the square locking tube  78  and the square aligning bar  76  to lock the locking bar  76  in place and hold the clamp  28  firmly. The top of the locking bar  76  is welded to the bottom of the locking rod sleeve  84  and sized to extend below the locking tube  78  when the knob  80  is fully depressed and locked in place by the spring loaded safety pin  88 . 
     In  FIG. 21 , there is shown a perspective view of the locking tube  78  having an opening  100  at its base sized to receive the spring loaded safety pin  88 . This tube  78  is welded to the spine portion  40  of the combined spine-handle  24  to receive the square aligning bar  76 . In  FIG. 22 , there is shown a perspective view of the locking cap  96  sized to fit within the top of the locking tube  78  and be welded thereto. It includes a central cylindrical opening  102  having a diameter sized to receive the locking rod  82  with a loose movable fit. 
     In  FIG. 23 , there is shown a perspective view of the locking rod sleeve  84  having an internal diameter  106  sized to receive the locking rod  82  and an external diameter  104  sized to be larger than the opening  102  ( FIG. 22 ) in the locking cap  96 . It has a length shorter than the distance between the knob  80  and the top of the locking tube  78  when the knob  80  is fully extended but sufficiently short so that when the knob  80  is pressed until the spring loaded safety in  88  locks the locking tube  78  in place, the locking bar  76  extends outwardly from the locking tube  78  to lock the material container clamp or hook  28  in place and thus prevent the substantially horizontal bar  74  from freeing itself from the lift arm  22  of the vehicle  16 . 
     In  FIG. 24 , there is shown a perspective view of the locking rod  82  having a bottom end  112  that is welded to the square aligning bar  76 , an external diameter  110  sized for a loose fit through the opening  102  ( FIG. 22 ) in the locking cap  96  ( FIG. 22 ) and sized for a loose fit within the cylindrical central opening  106  ( FIG. 23 ) of the rod sleeve  84  ( FIG. 23 ). At its upper end are recessed external threads  108  sized to be threaded into a tapped bore within the knob  80 . With this arrangement, the knob  80  may be threaded onto the locking rod  82 . The locking rod  82  extends downwardly and is held within the locking tube  78  by the welded square aligning bar  76  ( FIGS. 19 and 20 ). At its upper end, the knob  80  and the top of the locking tube  78  hold the helical compression spring  86  in place. 
     In  FIGS. 25 and 26 , there are shown respectively perspective views of the lower pivot tube  92  and the lower pivot pin  94 . The pivot tube  92  has an external diameter  116  welded to the combined spine-handle  24  at the bottom of its spine portion  40  and an internal diameter  114  sized for a loose rotatable fit with the external diameter  118  of the lower pivot pin  94 . The lower pivot pin  94  is welded to the material container clamp or hook  28  to permit pivoting of the clamp or hook  28  with respect to the spine portion  40  of the combined spine-handle  24 . 
     Although a preferred embodiment of the invention is described with some particularity, many modifications and variations may be made without deviating from the invention. Accordingly, it is to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.