Patent Publication Number: US-2006002785-A1

Title: Methods and apparatus for handling fragile bars

Description:
RELATED APPLICATIONS  
      This application is a Continuation in Part (CIP) of U.S. patent application Ser. No. 10/050,742 by Trpkovski filed on Jan. 15, 2002 the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates generally to methods and apparatus for handling material for the insulating glass industry. More particularly, the present invention relates to methods and apparatus for handling elongate barstock that is useful for forming components such as, for example, spacer frames and muntin bar lattices.  
     BACKGROUND OF THE INVENTION  
      Today, insulating glass units have achieved widespread use as building components. In order to produce insulating glass units inexpensively and in high volume, modern manufacturing of insulating glass units is often mechanized and/or automated. Various materials may be used to manufacture insulating glass units, including sheets of glass, spacer frames, and various sealants. Insulating glass units may also include muntin bars. Muntin bars may be used for both functional and decorative purposes with glass windows or doors. The muntin bars are particularly useful when they retain their geometric configuration and do not separate, as well as when they are able to remain in a flat mating surface relation with the glass.  
     SUMMARY OF THE INVENTION  
      The present invention relates generally to methods and apparatus for handling material for the insulating glass industry. More particularly, the present invention relates to methods and apparatus for handling elongate barstock that is useful for forming components such as, for example, spacer frames and muntin bar lattices. One method of handling material for the insulating glass industry in accordance with the present invention includes the step of arranging a plurality of bars into a plurality of stacks with adjacent stacks defining spaces dimensioned to receive a bar engaging member. The stacks of bars may then be transported to a desired destination. A bar engaging member may be inserted into a space defined by the stacks, and one or more bars may be grasped using the bar engaging member. In some implementations of the invention, the step of grasping one or more bars using the first bar engaging member includes the steps of inserting a second bar engaging member into a second space defined by the stacks and trapping one or more bars between the bar engaging member and the second bar engaging member.  
      A container for handling material for the insulating glass industry is also disclosed. In some implementations, the container includes a container frame and a plurality of combs selectively fixed to the frame. In one aspect of the present invention, each comb includes a plurality of tines that are spaced to define a plurality of channels dimensioned to accept bars having a predetermined width. In another aspect of the present invention, the tines are dimensioned to create spaces between adjacent channels, with each space being dimensioned to receive a bar engaging member. In some implementations, each tine comprises a shaft and a sleeve disposed over the shaft. The sleeve may advantageously comprise a no-mar material.  
      In some implementations, the present invention includes a container having a frame and a plurality of combs that are selectively fixed to the frame by a coupling mechanism. In some implementations, the coupling mechanism comprises a plunger fixed to the frame of the container and a detent defined by a base of the comb. The detent may be advantageously dimensioned to accept at least a portion of the plunger. The plunger may comprise, for example, a ball and a spring arranged to bias the ball toward the detent.  
      In certain advantageous implementations, the present invention utilizes a container including a first forklift interface and a second forklift interface. In some implantations, each forklift interface comprises a first receptacle and a second receptacle. Each receptacle may comprise, for example, a lumen defined by a tube. In some advantageous implementations, each forklift interface comprises a first tube positioned on a first side of a centroid of the container and a second tube disposed on a second side of the centroid of the container. When this is the case, the first tube and the second tube may be advantageously positioned substantially equidistantly from the centroid of the container.  
      A method of handling a first type of bars having a first dimension and a second type of bars having a second dimension is also disclosed. In some implementations, this method includes the step of providing a container including a frame and a first set of combs selectively fixed to the frame. Each comb in the first set of combs preferably has a plurality of tines spaced to accept bars having the first dimension. The first set of combs may be removed from the container and a second set of combs may be selectively fixed to the frame of the container. In certain implementations, each comb in the second set of combs advantageously has a plurality of tines spaced to accept bars having the second dimension.  
      Another method in accordance with the present invention may include the following steps:  
      1) Providing a container having a plurality of prearranged muntin bar retaining channels configured to hold a predetermined type of bars.  
      2) Placing a plurality of bars in the retaining channels of the container.  
      3) Placing a plurality of containers in a transportation vehicle. In some applications, the containers may be stacked in a semi trailer.  
      4) Removing the containers from the transportation vehicle.  
      5) Delivering at least one container to an arrival bay arranged to receive a container.  
      6) Sequentially removing bars from the container one at a time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a flow chart illustrating a method of handling material for the insulating glass industry.  
       FIG. 2  is a perspective view of a container in accordance with the present invention.  
       FIG. 3  is a perspective view of an assembly including a vehicle and a plurality of containers that are disposed within the walls of vehicle.  
       FIG. 4  is a plan view of an assembly including a semitrailer and a plurality of containers located within a plurality of walls of semitrailer.  
       FIG. 5  is a perspective view of a frame assembly in accordance with an exemplary embodiment of the present invention.  
       FIG. 6  is an exploded perspective view of a portion of frame assembly of  FIG. 5 .  
       FIGS. 7 through 10  are cross sectional plan views of containers in accordance with the present invention.  
       FIG. 11  is a perspective view of a system for automatically selecting and retrieving desired material from an appropriate container.  
       FIG. 12  is an additional perspective view a system of  FIG. 11 .  
       FIG. 13  is a cross sectional view of a container assembly in accordance with the present invention.  
       FIG. 14  is an additional cross sectional view of the container assembly of  FIG. 13 .  
       FIG. 15  is a perspective view of an additional exemplary embodiment of the present invention.  
       FIG. 16  is a perspective view of yet another exemplary embodiment of the present invention.  
       FIG. 17  is a diagrammatic view of a container in accordance with an additional exemplary embodiment of the present invention.  
       FIG. 18  is a diagrammatic view of a container in accordance with an additional exemplary embodiment of the present invention.  
       FIG. 19  is a diagrammatic view of a container in accordance with an additional exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION  
      The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements. All other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.  
       FIG. 1  is a flow chart  104  illustrating a method of handling material for the insulating glass industry. The material being handled may comprise, for example, bar stock useful in the insulating glass industry. Various types of bar stock may be used without deviating from the spirit and scope of the present invention. For example, bar stock suitable for forming spacer frames useful in the insulating glass industry may be used. By way of a second example, bar stock suitable for forming muntin bar lattices may also be used.  
      Bar stock used in the insulating glass industry often comprises thin sheet metal (e.g., 4.5 mil stainless steel, 6.0 mil aluminum, and the like). This thin sheet metal can be easily damaged during handling. For example, the bar stock may be scratched, bent and/or dented. Some types of bar stock may include a finish such as, for example, paint. This finish may be particularly susceptible to scratching.  
      Block  106 A of flow chart  104  comprises the step of providing a container. The container may be provided, for example, proximate a source of bar stock. This source of bar stock may be, for example, a factory where bar stock is fabricated. In a preferred method in accordance with the present invention, the container includes a plurality of prearranged bar locating members configured to hold a predetermined type of bar stock. In some methods in accordance with the present, the container is provided at a location where bar stock is being fabricated and the bar stock is placed in the container soon after being fabricated. Placing the bar stock in the contained soon after it is fabricated reduces the likelihood that the bar stock will be damaged.  
      In one exemplary embodiment, the bar locating members comprise tines which include a no-mar sleeve. The no-mar sleeve may reduce the likelihood that the outer surface of the bar stock is scratched during handling.  
      Block  106 B of flow chart  104  comprises the step of loading the container. The step of loading the container may involve placing a plurality of bars between the bar locating members of the container. This step may also involve arranging a plurality of bars into a plurality of stacks with adjacent stacks defining spaces dimensioned to receive a bar engaging member.  
      Block  106 C of flow chart  104  comprises the step of transporting the container. The step of transporting the container may involve placing a plurality of containers in a transportation vehicle. In some applications, the containers may be arranged in an interlocking fashion in the vehicle. The step of transporting the container may also involve removing the plurality of containers from the transportation vehicle. The step of transporting the container may also involve delivering at least one container to an arrival bay arranged to receive the container. The container may be delivered to the arrival bay using a vehicle, for example, a fork lift.  
      Block  106 D of flow chart  104  comprises the step of inserting a bar engaging member into a space defined by adjacent stacks of bar stock. Various bar engaging members may be utilized without deviating from the spirit and scope of the present invention. Bar engaging members suitable for some applications may comprise, for example, grippers, pinchers, fingers, and vacuum cups.  
      Block  106 E of flow chart  104  comprises the step of removing bar stock from the container. In some methods in accordance with the present invention, bar stock is removed one piece at a time. In other methods in accordance with the present invention, a plurality of pieces of bar stock are grasped and removed from the container.  
      Block  106 F comprises the step of returning the container. The container may be returned, for example, to the bar stock source. At the bar stock source, the container may by reloaded by placing a plurality of bars between the bar locating members of the container.  
       FIG. 2  is a perspective view of a container  1   00  in accordance with the present invention. Container  100  of  FIG. 2  includes a plurality of pre-arranged bar locating members  108  dimensioned and spaced for holding and dispensing a desired type of bar stock. Container  100  of  FIG. 2  also includes a first forklift interface  120 A and a second fork lift interface  120 B. First forklift interface  120 A comprises a plurality of receptacles  124 A that are preferably dimensioned to receive the forks of a forklift. In the embodiment of  FIG. 2 , each receptacle  124 A comprises a lumen  122 A defined by a beam  126 . Second forklift interface  120 B comprises a plurality of receptacles  124 B that are also preferably dimensioned to receive the forks of a forklift. In the embodiment of  FIG. 2 , each receptacle  124 B comprises a lumen  122 B defined by a cross member  128 . As shown in  FIG. 2 , each lumen  122 A has a central axis  123 A and each lumen  122 B has a central axis  123 B. In a preferred embodiment, the forks of a fork lift may be inserted into either end of lumens  122 A,  122 B.  
      Container  100  has longitudinal axis  101  and a lateral axis  103  that intersect at a centroid  168  of container  100 . In the embodiment of  FIG. 2 , beams  126  and cross members  128  both comprise lengths of tubing having a generally rectangular cross section. In  FIG. 2 , it may be appreciated that each forklift interface comprises a first tube positioned on a first side of centroid  168  of container  100  and a second tube disposed on a second side of centroid  168  of container  100 . In the embodiment of  FIG. 2 , the first tube and the second tube of each forklift interface are positioned substantially equidistantly from centroid  168  of container  100 .  
      In  FIG. 2  it may be appreciated that first forklift interface  120 A and a second fork lift interface  120 B are disposed at an angle relative to one another. In the embodiment of  FIG. 2 , each cross member  128  is arranged at about a 90 degree angle relative to each beam  126 .  
      In  FIG. 2 , it may be appreciated that container  100  includes a plurality of first mating elements  130  and second mating elements  132 . In the embodiment of  FIG. 2  each first mating element  130  comprises a post  134  and each second mating element  136  comprises a socket  138 . In some embodiments of the present invention, sockets  140  are dimensioned and located to accept the posts  142  of a second substantially similar container. Also in some embodiments of the present invention, sockets  140  are dimensioned and located to receive the alignment posts of workstation for locating container  100  in the workstation. Container  100  of  FIG. 2  also includes a sensor target  143  that is selectively coupled to container  100 . In  FIG. 2 , it may be appreciated that sensor target  143  has an offset location relative longitudinal axis  101  and a lateral axis  103 . Some methods in accordance with the present invention include the step of sensing the presence of sensor target  143  to verify that container  100  is properly oriented within the workstation.  
       FIG. 3  is a perspective view of an assembly including a vehicle  144  and a plurality of containers  25  that are disposed within the walls  74  of vehicle  144 . In some methods in accordance with the present invention, a plurality of containers  25  are mated with one another in an interlocking stacked configuration. In the embodiment of  FIG. 3 , vehicle  144  comprises a semitrailer  150 . It is to be appreciated that a container may be transported using various vehicles without deviating from the spirit and scope of the present invention. Examples of vehicles which may be suitable in some applications include trucks, airplanes, ships, trains, and fork lifts.  
       FIG. 4  is a plan view of an assembly including a semitrailer  150  and a plurality of containers  25  located within a plurality of walls  74  of semitrailer  150 .  
       FIG. 5  is a perspective view of a frame assembly  152  in accordance with an exemplary embodiment of the present invention. Frame assembly  152  includes a frame  154  and a plurality of combs  156  that are selectively coupled to frame  154 . Each comb  156  of frame assembly  152  comprises a base  158  and a plurality of tines  160  extending away from the base  158 . Frame  154  of frame assembly  152  includes a plurality of beams  126  and a plurality of cross members  128  fixed to beams  126 , for example by welding.  
      First forklift interface  120 A comprises a plurality of receptacles  124 A that are preferably dimensioned to receive the forks of a forklift. In the embodiment of  FIG. 2 , each receptacle  124 A comprises a lumen  122 A defined by a beam  126 . Second forklift interface  120 B comprises a plurality of receptacles  124 B that are also preferably dimensioned to receive the forks of a forklift. In the embodiment of  FIG. 2 , each receptacle  124 B comprises a lumen  122 B defined by a cross member  128 . As shown in  FIG. 2 , each lumen  122 A has a central axis  123 A and each lumen  122 B has a central axis  123 B. In a preferred embodiment, the forks of a fork lift may be inserted into either end of lumens  122 A,  122 B.  
      Frame  154  has longitudinal axis  125  and a lateral axis  127  that intersect at a centroid.  168  of frame  154 . In the embodiment of  FIG. 5 , beams  126  and cross members  128  both comprise lengths of tubing having a generally rectangular cross section. In  FIG. 5 , it may be appreciated that each forklift interface comprises a first tube positioned on a first side of a centroid of the container and a second tube disposed on a second side of the centroid of the container. In the embodiment of  FIG. 5 , the first tube and the second tube of each forklift interface are positioned substantially equidistantly from the centroid of the container. In  FIG. 5  it may be appreciated that first forklift interface  120 A and a second fork lift interface  120 B are generally orthogonal to one another. In the embodiment of  FIG. 5 , each cross member  128  is arranged at about a 90 degree angle relative to each beam  126 .  
      Frame  154  of  FIG. 5  also includes a sensor target  143  that is selectively coupled to frame  154 . In  FIG. 5 , it may be appreciated that sensor target  143  has an offset location relative longitudinal axis  125  and a lateral axis  127  of frame  154 . Some methods in accordance with the present invention include the step of sensing the presence of sensor target  143  to verify that frame  154  is properly oriented within a workstation.  
       FIG. 6  is an exploded perspective view of a portion of frame assembly  152  of  figure 5 . In the embodiment of  FIG. 6 , one comb  156  is shown in a detached position. In some embodiments of the present invention, combs  156  are selectively coupled to frame  154  by a coupling mechanism  174 . In the embodiment of  FIG. 6 , coupling mechanism  174  comprises a plunger  176  that is fixed to frame  154  and a detent  178  defined by base  158  of comb  156 . Detent  178  is preferably dimensioned to accept at least a portion of plunger  176 . Plunger  176  may comprise, for example, a ball and a spring that is arranged to bias the ball toward detent  178 .  
      In  FIG. 6 , it may be appreciated that each tine  180  includes a shaft  182  and a sleeve  184  that is disposed about shaft  182 . In a preferred embodiment, each sleeve  184  comprises a no-mar material that is selected to avoid damaging, marking, or causing blemishes on a bar stock material. Various no-mar materials may be used without deviating from the spirit and scope of the present invention. Examples of no-mar materials which may be suitable in some applications include polymeric materials (e.g., polyethylene and polypropylene) and elastomeric materials (e.g., polyurethane). It is to be appreciated that a container in accordance with the present invention may be configured to carry a desired type of bar stock by installing combs having tines that are dimensioned and spaced to receive the desired bar stock.  
       FIGS. 7 through 10  are cross sectional plan views of containers  100  in accordance with the present invention. Each container  100  includes a plurality bar locating members  108  that are preferably dimensioned and spaced for receiving desired pre-sized bars  188 . In  FIGS. 7 through 10 , it may be appreciated that bar locating members  108  are spaced to define a plurality of channels  162  dimensioned to accept bars having a given width. In the embodiments illustrated in  FIGS. 7 through 10 , a stack  228  of bars  188  is disposed within each channel  162 . Also in  FIGS. 7 through 10 , it may be appreciated that bar locating members  108  are dimensioned to create spaces  164  between adjacent channels  162 . In a preferred embodiment, each space  164  is dimensioned to receive a bar engaging member. In this preferred embodiment, each space  164  has dimensions suitable to allow access of a portion of a selection and retrieval subsystem to automatically select and retrieve bars  188  from the container, and deliver the bars to a desired location. The containers  100  illustrated in  FIGS. 7 through 10  also include a plurality of casters  252 . Casters  252  may facilitate movement of the containers. Containers may include, for example, casters, rollers, and wheels without deviating from the spirit and scope of the present invention.  
       FIG. 11  is a perspective view of a system  192  for automatically selecting and retrieving desired material from an appropriate container. System  192  includes a plurality of bays  194 . Each bay  194  is preferably configured to receive a container. In the embodiment of  FIG. 11 , each bay  194  includes a plurality of alignment pins  198 . In a preferred embodiment, each bay  194  also includes a sensor  145  that is adapted to detect the presence of a sensor target  143 . One sensor  145  is shown in  FIG. 11 . In some methods in accordance with the present invention include the sensor  145  and sensor target  143  fixed to a container may be used to verify that the container is properly oriented within a bay of system  192 .  
      System  192  also includes a bar engaging assembly  200  that is coupled to a motion control system  196 . In the embodiment of  FIG. 11 , bar engaging assembly  200  includes a plurality of bar engaging members  202 . In some embodiments of the present invention, two or more bar engaging members  202  may be selectively urged towards one another to trap one or more bars. The force used to urge two or more bar engaging members  202  towards one another may be provided by, for example, one or more air cylinders.  
      In the embodiment of  FIG. 11 , motion control system  196  includes a z-axis linear actuator  204 , an x-axis linear actuator  206  and a plurality of y-axis linear actuators  208 . In a preferred embodiment, motion control system  196  is capable of selectively placing bar engaging assembly  200  in a desired position. Motion control system  196  may comprise various elements without deviating from the spirit and scope of the present invention. For example, motion control system  196  may comprise one or more robots, one or more linear actuators, and/or one or more rotary actuators. Linear actuators which may be suitable in some applications are commercially available from Lintech Corporation of Monrovia, California and Tol-o-matic Corporation of Hamel, Minn.  
      System  192  also includes a conveyor  220  that preferably extends through at least a portion of system  192 . In some methods in accordance with the present invention, conveyor  220  may be utilized to transport material from system  192  to a desired location. In the embodiment of  FIG. 11 , conveyor  220  includes a belt  222  and a plurality of rollers  224 . Bar engaging assembly  200  and motion control system  196  may be used to retrieve bars and place them on belt  222  of conveyor  220 .  
       FIG. 12  is an additional perspective view of system  192  of  FIG. 11 . In the embodiment of  FIG. 12 , a container  100  has been positioned in each bay  194 . For purposes of illustration, a portion of each container  100  is cut-away to reveal an alignment pin  198 . Thus, in  FIG. 12 , it may be appreciated that each container  100  includes a plurality of sockets  140  that are dimensioned to receive an alignment pin  198 . In some methods in accordance with the present invention, alignment pins  198  may be used to locate containers  100  relative to system  192 .  
      In  FIG. 12 a  sensor target  143  is shown fixed to one container  100 . In the embodiment of  FIG. 12 , sensor target  143  is disposed-in alignment with sensor  145  when container  100  is correctly oriented in a bay  194 . In a preferred embodiment, sensor  145  is adapted to detect the presence of sensor target  143 . Sensor  145  may comprise various sensors without deviating from the spirit and scope of the present invention. For example, sensor  145  may comprise an arm that mechanically contacts sensor target  143  and trips a switch. By way of another example, sensor  145  may be an optical sensor which generates a beam that is broken and/or reflected by sensor target  145 . By way of yet another example, sensor  145  may sense the presence of sensor target using a change in inductance or capacitance.  
      In the embodiment of  FIG. 12 , each container  100  holds a plurality of bar stock stacks  228  which are illustrated somewhat diagramatically in  FIG. 12 . In some embodiments, each stack  228  comprises a plurality of bars  230  arranged one on top of the other. One bar  230  shown held by bar engaging members  202  of bar engaging assembly  200 . Bar engaging assembly  200  and motion control system  196  may be used to select a container  100  containing a plurality of desired bars, remove a desired bar, and place the desired bar on belt  222  of conveyor  220 . In  FIG. 12 , one bar  230  can be seen resting on belt  222  of conveyor  220 .  
       FIG. 13  is a cross sectional view of a container assembly  234  in accordance with the present invention. Container assembly  234  includes a container  100  having a plurality of bar locating members  108 . A plurality of bars  230  are disposed between adjacent bar locating members  108  to form stacks  228 . In  FIG. 13 , a first bar engaging member  202 A can be seen disposed within a first space  164 A defined by a plurality of bars  230 . A second bar engaging member  202 B is disposed in a second space  164 B defined by a plurality of bars  230 .  
      In the embodiment of  FIG. 13 , first bar engaging member  202 A and second bar engaging member  202 B have been urged towards one another, and a top bar  230 A has been captured between first bar engaging member  202 A and second bar engaging member  202 B. In  FIG. 13 , it may be appreciated that first bar engaging member  202 A and second bar engaging member  202 B are both disposed above a plane P defined by the top surface of a second bar  230 B.  
       FIG. 14  is an additional cross sectional view of the container assembly  234  of  FIG. 13 . In the embodiment of  FIG. 14 , first bar engaging member  202 A and second bar engaging member  202 B have been moved to a new position, for example, using motion control system  196 .  
      In  FIG. 14 , it may be appreciated that top bar  230 A has been removed from container  100  by first bar engaging member  202 A and second bar engaging member  202 B. In some methods in accordance with the present invention, top bar  230 A may be removed from container  100  by moving top bar  230 A in a direction that is generally perpendicular to a top surface S of second bar  230 B. In  FIG. 14 , it may be appreciated that plane P is defined by top surface S of second bar  230 B. Plane P is illustrated with a phantom line in  FIG. 14 .  
       FIG. 15  is a perspective view of an additional exemplary embodiment of the present invention. A stack  340  comprising a plurality of bars  342  is shown in  FIG. 15 . Stack  340  includes a top bar  342 A and a second bar  342 B. In  FIG. 15 , a first finger  344  and a second finger  346  are positioned proximate top bar  342 A. A finger sleeve  348  of first finger  344  is shown contacting a first side  350  of top bar  342 A and a finger sleeve  348  of second finger  346  is shown contacting a second side  352  of top bar  342 A. In  FIG. 15  it may be appreciated that first finger  344  and second finger  346  are both positioned above a plane P defined by a top surfaces S of second bar  342 B. In some methods in accordance with the present invention, first finger  344  and a second finger  346  may be used to lift top bar  342 A from stack  340 .  
       FIG. 16  is a perspective view of yet another exemplary embodiment of the present invention. In  FIG. 16 , a first tine  454  and a second tine  456  are laterally spaced from one another so that first tine  454  and second tine  456  define a channel  458 . In the embodiment of  FIG. 16 , a bar  442  is disposed within channel  458 . First tine  454  comprises a tine shaft  460  and a tine sleeve  462  disposed about tine shaft  460 . Second tine  456  also comprises a tine sleeve  462  disposed about a tine shaft  460 . In  FIG. 16 , tine sleeve  462  of first tine  454  is shown contacting a first side  450  of bar  442  at a first tine interface  464 . Also in  FIG. 16 , tine sleeve  462  of second tine  456  is shown contacting a second side  452  of bar  442  at a second tine interface  466 .  
      In the embodiment of  FIG. 16 , a first finger  444  is disposed within a first space  468  defined in part by first fine  454 . Also in the embodiment of  FIG. 16 , a second finger  446  is disposed within a second space  470  defined in part by second tine  456 . First finger  444  comprises a finger shaft  472  and a finger sleeve  448  disposed about finger shaft  472 . Second finger  446  also comprises a finger sleeve  448  disposed about a finger shaft  472 . In  FIG. 16 , finger sleeve  448  of first finger  444  is shown contacting a first side  450  of bar  442  at a first finger interface  474 . Also in  FIG. 16 , finger sleeve  448  of second finger  446  is shown contacting a second side  452  of bar  442  at a second finger interface  476 . In some embodiments of the present invention, each finger interface has a finger interface coefficient of friction and each tine interface has a tine interface coefficient of friction. In certain advantageous embodiments of the present invention, the finger interface coefficient of friction is generally greater than the fine coefficient of friction. With reference to  FIG. 16 , it will be appreciated that because first finger  444  and second finger  446  include not laterally extending surfaces, these fingers are retaining bar  442  through frictional engagement only. When the finger interface coefficient of friction is generally greater than the tine coefficient of friction first finger  444  and second finger  446  are able to pull bar  442  out of channel  458  defined by first tine  454  and second tine  456 .  
       FIG. 17  is a diagrammatic view of a container  500  in accordance with an additional exemplary embodiment of the present invention. Container  500  includes a frame  580 , a longitudinal axis  582 , and a lateral axis  584 . In the embodiment of  FIG. 17 , a centroid  586  of container  500  is located at an intersection of longitudinal-axis  582  and lateral axis  584 . Container  500  of  FIG. 17  also includes a sensor target  588  that is selectively coupled to frame  580 . In  FIG. 17 , it may be appreciated that sensor target  588  has an offset location relative lateral axis  584  and longitudinal axis  582 . Container  500  of  FIG. 17  also includes a plurality of sockets  592  which may be used to locate container  500  within a workstation. Some methods in accordance with the present invention include the step of sensing the presence of sensor target  588  to verify that container  500  is properly oriented within the workstation.  
      In the embodiment of  FIG. 17 , container  500  includes a plurality of tines  590  that are laterally spaced apart to define a plurality of channels  594 . Also in the embodiment of  FIG. 17 , tines  590  are longitudinally spaced about to define a plurality of spaces  596 . A proximal stack  540  comprising a plurality of bars  542  is disposed between a first tine  590 A and second tine  590 B. If  FIG. 17  it may be appreciated that a proximal side  502  of proximal stack  540  is located a first distance D 1  from a distal socket  592 A.  
      In some methods in accordance with the present invention, a plurality of containers containing various types of bars are provided for use with a workstation. In some cases the various types of bars may have different widths. In the embodiment of  FIG. 17 , each bar  542  has a width W 1 . In some advantageous methods, the distance between a distal socket of each container and the proximal side of a proximal stack of bars held by the container is the same for all containers. In these advantageous methods, the proximal side of the proximal stack of bars is located in a consistent location regardless of the type of bar that is held in a particular container.  
       FIG. 18  is a diagrammatic view of a container  600  in accordance with an additional exemplary embodiment of the present invention. Container  600  includes a first tine  690 A and a second tine  690 B that define a channel  658 . A proximal stack  640  comprising a plurality of bars  642  is disposed in channel  658  (i.e., between first tine  690 A and second tine  690 B). In the embodiment of  FIG. 18 , bars  642  of proximal stack  640  have a width W 2 .  
      In  FIG. 18  it may be appreciated that a proximal side  602  of proximal stack  640  is located a distance D 2  from a proximal socket  692 A. In the exemplary embodiment of  FIG. 18 , distance D 2  is substantially equal to distance D 1  shown in  FIG. 17 . This is the case, even though width W 2  shown in  FIG. 18  is different than width W 1  shown in  FIG. 17 . A distal stack  640 ′ comprising a plurality of bars  642  is also shown if  FIG. 18 . A distal side  606  of distal stack  640 ′ is located a distance D 3  from a distal socket  692 B. In  FIG. 18 , distance D 3  is generally greater than distance D 2 .  
       FIG. 19  is a diagrammatic view of a container  700  in accordance with an additional exemplary embodiment of the present invention. In  FIG. 19 , a first tine  754  and a second tine  756  are laterally spaced from one another so that first tine  754  and second tine  756  define  30  a channel  758 . In the embodiment of  FIG. 19 , a bar  742  is disposed within channel  758 . In the embodiment of  FIG. 19 , each tine comprises a tine shaft  760  and a tine sleeve  762  disposed about the tine shaft  760 . In  FIG. 19 , tine sleeve  762  of first tine  754  is shown contacting a first side  750  of bar  742  at a first tine interface  764 . Also in  FIG. 19 , tine sleeve  762  of second tine  756  is shown contacting a second side  752  of bar  742  at a second tine interface  766 .  
      In the exemplary embodiment of  FIG. 19 , bar  742  has width B and channel  758  has a width C when the sleeves of the tines defining channel  758  are allowed to assume a resting shape. With reference to  FIG. 19 , it may be appreciated that width B is generally larger than width C. In  FIG. 19 , it may also be appreciated that tine sleeve  762  of first tine. 754  and tine sleeve  762  of second tine  756  are shown assuming a generally deformed shape.  
      In the embodiment of  FIG. 19 , a first finger  744  is disposed within a first space  768  defined in part by first tine  754 . Also in the embodiment of  FIG. 19 , a second finger  746  is disposed within a second space  770  defined in part by second tine  756 . A third finger  745  and a fourth finger  747  are also shown in  FIG. 19 . In the embodiment of  FIG. 19 , each finger comprises a finger shaft  772  and a finger sleeve  748  disposed about the finger shaft  772 . In  FIG. 19 , finger sleeve  748  of first finger  744  is shown contacting a first side  750  of bar  742  at a first finger interface  774 . Also in  FIG. 19 , finger sleeve  748  of second finger  746  is shown contacting a second side  752  of bar  742  at a second finger interface  776 . In some embodiments of the present invention, each finger interface has a finger interface coefficient of friction and each tine interface has a tine interface coefficient of friction. In certain advantageous embodiments of the present invention, the finger coefficient of friction is generally greater than the tine coefficient of friction.  
      Each tine sleeve  762  and each finger sleeve  748  may comprise various materials without deviating from the spirit and scope of the present invention. Examples of materials which may be suitable in some applications include, polymeric materials (e.g., polyethylene) and elastomeric materials (e.g., polyurethane). In some cases, each sleeve may comprise a foam material (e.g., a closed cell foam material). In some embodiments of the present invention, each finger sleeve has a first hardness and each tine sleeve has a second hardness with the first hardness being greater than the second hardness. In some embodiments of the present invention, each finger sleeve has a first durometer and each tine sleeve has a second durometer with the first durometer being greater than the second durometer. In some embodiments of the present invention, each finger sleeve has a first modulus and each tine sleeve has a second modulus with the first modulus being greater than the second modulus.  
      Numerous characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size and ordering of steps without exceeding the scope of the invention. The invention&#39;s scope is, of course, defined in the language in which the appended claims are expressed.