Abstract:
The present disclosure provides a method of delivering a container ( 103 ) to a marking apparatus ( 100 ), wherein the marking apparatus ( 100 ) is of the type having a marking device for selectively applying a mark to a container ( 103 ). The method comprises providing a plurality of containers within a staging assembly ( 104 ), and isolating at least one container ( 103 ) within a singulator assembly ( 112 ), wherein the singulator assembly ( 112 ) is in communication with the staging assembly ( 104 ). The method further comprises transporting the at least one container ( 103 ) from the singulator assembly ( 112 ) to a portion of the marking apparatus ( 100 ) with a shuttle ( 210 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/816,214, filed on Jun. 23, 2006, the disclosure of which is hereby expressly incorporated by reference. 
    
    
     BACKGROUND 
     Bar coding in patient care and medication delivery is now mandated to administer patient dosing and prevent wrong dosing or inadvertent delivery of medication to the wrong patient. A labeling apparatus has been developed for delivering labels to medical containers, which is described fully in U.S. Patent Application Publication No. US 2005/0115681 A1, entitled “Method and Apparatus for Delivering Barcode-to-Dose Labels, filed on Aug. 13, 2004. 
     To use the aforementioned labeling apparatus, the user must manually feed the container into a portion of the apparatus, and the labeling apparatus thereafter delivers a label to the container. Thus, to deliver labels to a plurality of containers, each container must be individually fed into the apparatus, which is time-consuming and wasteful of resources. 
     SUMMARY 
     The present disclosure provides a method of delivering a container to a marking apparatus, wherein the marking apparatus is of the type having a marking device for selectively applying a mark to a container. The method comprises providing a plurality of containers within a staging assembly, and isolating at least one container within a singulator assembly, wherein the singulator assembly is in communication with the staging assembly. The method further comprises transporting the at least one container from the singulator assembly to a portion of the marking apparatus with a shuttle. 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an isometric view of an auto-feed apparatus constructed in accordance with one embodiment of the present disclosure coupled to a labeling apparatus; 
         FIG. 2  is a partial isometric view of the staging assembly of the auto-feed apparatus of  FIG. 1 ; 
         FIG. 3  is a front partial isometric view of the auto-feed apparatus of  FIG. 1 ; 
         FIG. 4  is a rear partial isometric view of the auto-feed apparatus of  FIG. 3 ; 
         FIG. 5  is a front partial isometric view of the auto-feed apparatus of  FIG. 3 ; 
         FIG. 6A  is a top planar view of the singulator device of the auto-feed apparatus of  FIG. 1  receiving a container of a first diameter; 
         FIG. 6B  is a top planar view of the singulator device of the auto-feed apparatus of  FIG. 6A  receiving a container of a second diameter; 
         FIG. 7A  is a side planar view of a shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus, wherein a container is disposed within the shuttle; 
         FIG. 7B  is a side planar view of  FIG. 7A , showing the pushrod and container translated within the shuttle; 
         FIG. 8A  is a side planar view of the shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus of  FIG. 7B , showing the clamp of the clamp assembly lowered to engage the container; 
         FIG. 8B  is a side planar view of  FIG. 8A , showing the shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus translated; 
         FIG. 8C  is a side planar view of the shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus translated linearly forward so that the container is fed into the labeling apparatus; 
         FIG. 8D  is a side planar view of the shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus translated linearly forward, wherein the container is being labeled by the labeling apparatus; 
         FIG. 8E  is a side planar view of the shuttle, pushrod, end block, clamp assembly, and camming device of the auto-feed apparatus translating rearwardly and allowing the container to fall into a tray below; and 
         FIG. 9  is a block diagram showing a control schematic for the combination auto-feed apparatus and labeling apparatus of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An auto-feed assembly, or auto-feed apparatus  102 , constructed in accordance with one embodiment of the present disclosure is best seen by referring to  FIG. 1 . The auto-feed apparatus  102  delivers containers  103 , which are preferably vials to a marking apparatus, or labeling apparatus  100 . In turn, the labeling apparatus  100  applies a mark or label to the container  103 . The labeling apparatus  100 , and the method of delivering the labels to the containers  103 , is described fully in U.S. Patent Application Publication No. US 2005/0115681 A1, entitled “Method and Apparatus for Delivering Barcode-to-Dose Labels, filed on Aug. 13, 2004, the disclosure of which is hereby expressly incorporated by reference. From time to time throughout this specification, directional terms, such as interior, exterior, top, bottom, etc., are used in the description of various components. It should be apparent that the use of such terms is merely for convenience and, as such, is not intended to be limiting. 
     The auto-feed apparatus  102  is supported on a mount plate  120 , which is coupled to the labeling apparatus  100  in any well-known manner. A tray  134  is stowed beneath the mount plate  120  for receiving containers  103  that have been labeled by the labeling apparatus  100 . 
     Referring to  FIG. 2 , the auto-feed apparatus  102  includes a staging assembly  104  positioned above the mount plate  120 . The staging assembly  104  includes an infeed table  106  which is mounted to the mount plate  120  in any well-known manner such that the infeed table  106  is directed downwardly toward the labeling apparatus  100 . The infeed table  106  includes first and second substantially straight edges  131  and  133 . 
     A singulator assembly  112  and a drive assembly  114  are placed in communication with the staging assembly  104  for processing the containers  103 . Preferably, the singulator assembly  112  is mounted to the infeed table  106  along at least a portion of the second straight edge  133 , and the drive assembly  114  is mounted along the first straight edge  131 . A gap is defined between the singulator assembly  112  and the drive assembly  114  along the second straight edge  131 . This gap defines a feed channel  118  that is used to funnel containers  103  toward the lower corner of the infeed table  106  defined by the intersection of the first and second straight edges  131  and  133 . 
     The singulator assembly  112  is enclosed within a singulator housing  155  having an L-shaped front cover  108  (see  FIGS. 6A and 6B ) and a singulator top cover  110 . Referring to  FIG. 2 , a rail support  178  is mounted on the infeed table  106  inwardly of and substantially parallel to the second straight edge  133 . First and second runner blocks  182  are mounted to the exterior surface of the vertical portion of the rail support  178 . 
     A guide rail  180  is slidably received within the first and second runner blocks  182 . As can best be seen by referring to  FIGS. 6A and 6B , the guide rail  180  is mounted to the interior surface (not shown) of the front cover  108  so that the front cover  108  is linearly displaceable along the vertical portion of the rail support  178 , as described in greater detail below. 
     Still referring to  FIGS. 6A and 6B , an extension spring  184  is positioned along the exterior surface of the vertical portion of the rail support  178  above the guide rail  180 . The extension spring  184  is mounted at one end to the exterior surface of the rail support  178  and at the other end to the interior surface of the longitudinal portion of the front cover  108 . The extension spring  184  biases the front cover  108  in a direction opposite the first straight edge  131  of the infeed table  106  and therefore holds the shortened portion of the front cover  108  in tension against the adjustment mechanism  156  (described in detail below). 
     Referring back to  FIG. 2 , the singulator assembly  112  further includes a retention device  172  that protrudes through a horizontal slot in the shortened portion of the front cover  108  (not shown). The retention device  172  is selectively engageable with the body of a container  103  positioned within the feed channel  118  (see  FIG. 1 ) for maintaining the position of said container  103  therewithin. The retention device  172  is operably coupled to an output push pole (not shown) of a single throw solenoid tubular push  170 . A substantially L-shaped retention solenoid mount  168  mounted to the infeed table  106  along the edge of its vertical portion receives the forward end of the single throw solenoid tubular push  170 . The vertical portion of the retention solenoid mount  168  is positioned adjacent and substantially orthogonal to the front end of the rail support  178 . 
     The horizontal portion of the retention device solenoid mount  168  is positioned above the retention device  172  and includes a retention device guide  174  mounted therebeneath. A guide channel  175  is formed longitudinally along the bottom surface of the retention device guide  174 . The guide channel  175  receives the upper end of a guiding shaft  176 , and the lower end of the guiding shaft  176  is coupled to the top of the retention device  172 . In this manner, when the retention device  172  is linearly translated by the single throw solenoid tubular push  170 , it follows the path of the guiding shaft  176  within the guide channel  175 . An extension spring  177  extends between the vertical portion of the retention device solenoid mount  168  and the guiding shaft  176 . The extension spring  177  biases the retention device  172  towards the retention solenoid mount  168  when the retention device  172  is not linearly actuated by the single throw solenoid tubular push  170 . 
     The singulator assembly  112  further includes an adjustment mechanism  156  for adjusting the position of the retention device  172  within the feed channel  118  and the linear position of the front cover  108 . The adjustment mechanism  156  includes a retention bracket  166  which is mounted to the upper surface of the horizontal portion of the retention solenoid mount  168 . 
     The adjustment mechanism  156  further includes a thumbscrew that passes through a longitudinal slot formed in singulator top cover  110  (See  FIG. 1 ). After passing through the longitudinal slot, the thumbscrew shaft receives an annular spacer  160  and is thereafter threadably received within a threaded opening in the retention device bracket  166 . The upper end of the thumbscrew includes an annular shoulder and an adjustment knob  158 . As shown in  FIGS. 1 and 2 , the shoulder of the thumbscrew is larger in diameter than the width of the longitudinal slot such that the shoulder of the thumbscrew and the adjustment knob  158  are positioned on the exterior of the singulator top cover  110 . 
     Still referring to  FIG. 2 , a runner block  162  is coupled to the upper surface of the retention device bracket  166  adjacent to spacer  160 . The runner block  162  is slidably received on a guide rail  164 , which is mounted to the bottom surface of the singulator top cover  110  (not shown). 
     The adjustment knob  158  is turned clockwise to drive the thumbscrew within the retention device bracket  166 , and the singulator top cover  110  is clamped between the thumbscrew shoulder and the spacer  160 . In this manner, the adjustment knob  158  and thumb screw cannot move relative to the singulator top cover  110 . Therefore, the retention device solenoid mount  168 , the single throw solenoid tubular push  170 , and the retention device  172 , which are coupled to the thumbscrew and adjustment knob  158  through the retention device bracket  166 , are likewise locked in position relative to the singulator top cover  110 . 
     When the adjustment knob  158  is loosened such that the singulator top cover  110  is no longer clamped between the thumbscrew shoulder and the spacer  160 , the adjustment knob  158  can move within the longitudinal slot of the singulator top cover  110 . Therefore, the retention bracket  166 , the retention device solenoid mount  168 , the single throw solenoid tubular push  170 , and the retention device  172  are also moveable beneath the singulator top cover  110 . The path of movement of the adjustment mechanism  156  is controlled through the slidable translation of the runner block  162  along the guide rail  164 . 
     Referring to  FIG. 1 , the drive assembly  114  is housed within a drive housing  140  coupled to the infeed table  106 . As can best be seen by referring to  FIG. 2 , the drive assembly  114  includes first and second timing pulleys  142  and  144 . The first timing pulley  142  is operably coupled to the output shaft of a motor  148  mounted to the underside of the infeed table  106 . Preferably, a permanent magnet DC motor  148  is used to selectively drive the first timing pulley  142 . A longitudinal belt backer  152  is coupled to infeed table  106  and is positioned between the first and second timing pulleys  142  and  144 . 
     The first and second timing pulleys  142  and  144  are interconnected by a timing belt  146 . As shown in  FIG. 3 , a portion of the timing belt  146  is exposed through a slot in the side of the belt drive housing  140  facing inwardly toward the infeed table  106 . The timing belt  146  is engageable with containers  103  when they are loaded onto the infeed table  106  of the staging assembly  104 , and the clockwise movement of the belt  146  urges the containers  103  downwardly toward the feed channel  118 . 
     Referring to  FIG. 1 , a gate  119  is displaceable along the second straight edge  133  of the infeed table  106  in the gap between the singulator  112  and the drive assembly  114 , or along the lower edge of the infeed channel  118 . As shown in  FIG. 3 , the gate  119  includes a door portion  186  and a bracket portion  188 . The door portion  186  is slideable along the bottom straight edge of the infeed table  106  and is positioned substantially perpendicular thereto. 
     Referring to  FIG. 4 , the bracket portion  188  curves downwardly towards the underside of the infeed table  106  such that it is substantially parallel to the bottom surface of the infeed table  106 . The inner surface of the bracket portion  188  is coupled to the bottom of a runner block  190  which is slidably received on a guide rail  192 . The guide rail  192  is secured to the underside of the infeed table  106  proximate to the second straight edge  133  and substantially parallel thereto. 
     The outer surface of the bracket portion  188  includes a flange bearing  198   a , which is pivotally and slidably received within a slot formed in one end of a gate link  196 . The gate link  196  extends inwardly from the bracket portion  188  of the door  119  toward the middle of the infeed table  106 , and the second end of the gate link  196  is pivotally coupled to the infeed table through a flange bearing  198   b  and annular spacer  200 . A link pusher plate  202  is coupled to the gate link  196  in between flange bearings  198   a  and  198   b . The link pusher plate  202  extends downwardly and slightly outwardly from the gate link  196 , and the rear surface of the link pusher plate  202  abuts the end of a linear push rod  254 . 
     To displace the gate  119  along the second straight edge  133  of the infeed table  106  away from the first straight edge  131 , thereby “opening” the bottom of the feed channel  118 , the linear pushrod  254  is translated rearward to displace the link pusher plate  202  and cause the gate link  196  to rotate upwardly about flange bearing  198   b . The upward rotation of the gate link  196  translates the bracket portion  188  and the runner block  190  upwardly and linearly along the guide rail  192 . As a result, the door portion  186  of the gate  119  is slidably translated along the second straight edge  133  until the bottom of the feed channel  118  is open. 
     An extension spring  194  is coupled at one end to the runner block  190  and at the opposite end to the underside of the infeed table  106  near the first straight edge  131 . When the pushrod  254  is translated forwardly within the shuttle  210  and is no longer engaging the link pusher plate  202 , the extension spring  194  urges the bracket portion  188  to slide linearly along the guide rail  192  toward the first straight edge  131 . At the same time, the door portion  186  is slidably translated along the second straight edge  133  of the infeed table  106  until the gate  119  is positioned along the bottom opening of the feed channel  118 , thereby “closing” the gate  119 . 
     Referring back to  FIG. 3 , a shuttle flap  204  is coupled to the exterior surface of the door portion  186  of the gate  119  and extends toward the mount plate  120 . A weight  206  is coupled to the end of the shuttle flap  204  opposite the gate  119  to bias the shuttle flap  204  in a downward direction. 
     Still referring to  FIG. 3 , the auto-feed apparatus  102  includes a shuttle assembly  208  coupled to the mount plate  120  beneath the staging assembly  104 . As can best be seen by referring to  FIG. 5 , the shuttle device  208  includes a shuttle  210 . A shuttle guide  213  extends upwardly and outwardly from the edge of shuttle  210  (see  FIG. 5 ) for guiding the containers  103  into the shuttle  210 . A guide rail  212  is mounted to the shuttle  210  along its first side exterior surface. The guide rail  212  is slidably received within a horizontal runner block  214  mounted on its bottom surface to the mounting portion  218  of a vertical rotation cam path plate  216  of a camming device  215 . 
     The rotation cam path plate  216  of the camming device  215  is vertically mounted along its bottom edge to the mount plate  120 , and it extends from the forward portion of the shuttle  210  to the forward edge of the mount plate  120 . The mounting portion  218  of the rotation cam path plate  216  is positioned adjacent to the forward portion of the shuttle  210 , and a cam path portion  220  extends along the bottom of the rotation cam path plate  216  and forwardly of the mounting portion  218 . 
     A slot is formed between the mounting portion  218  and the cam path portion  220  to define the proximal end of the cam path portion  220  and a cam surface  219 , which extends along the upper edge of the cam path portion  220 . A divot  221  is formed along the cam surface  219  beneath the forward end of the mounting portion  218 . A substantially vertical lip  223  is formed along the cam surface  219  at the distal end of the cam path portion  220 . 
     Still referring to  FIG. 5 , a mushroom-shaped rotator cam  224  is positioned adjacent and abutting the rotation cam path plate  216 . The rotator cam  224  includes a stem  225  extending outwardly from a cap  227  having first and second weighted portions  226  and  228  formed on either side of the stem  225 . The stem  225  is initially positioned horizontally adjacent the slot defined by the mounting portion  218  and the cam path portion  220  of the cam path plate  216 . The cap  227  is positioned adjacent to the rear end of the rotation cam path plate  216  with the first weighted portion  226  being positioned above the second weighted portion  228 . 
     Referring to  FIGS. 3 and 5 , the rotator cam  224  is coupled to an end stop  234 , which is positioned adjacent the forward end of the shuttle  210 . A thru-rod  230  extends orthogonally through the end of the stem  230  and is received into the side of a lower shuttle pivot plate  248  of the end stop  234 . A shoulder screw  232  passes through the rotator cam  224  in the portion between the stem  225  and the cap  227  and is received into the rear end of the side of the lower shuttle pivot plate  248 . A roller bearing  217  (shown hidden in  FIGS. 8A and 8B ) is axially disposed on the thru-rod  230  and engages the cam surface  219  so that the rotator cam  224  is linearly and rotatably translatable along the path defined by the cam surface  219 . 
     Referring to  FIGS. 3 and 8A , the end stop  234  includes a front shuttle pivot plate  238  that is vertically positioned adjacent the forward end of the shuttle  210  and includes a V-shaped recess along its upper edge that aligns the correspondingly shaped surface of the shuttle  210 . The front shuttle pivot plate  238  extends downwardly from the shuttle  210 , and the bottom edge of the shuttle pivot plate  238  is coupled to the front upper surface of the lower shuttle pivot plate  248 . The upper surface of the lower shuttle pivot plate  248  is coupled to the bottom surface of a cradle pivot plate  250 , which extends upwardly therefrom and is coupled to the underside of the shuttle  210 . 
     An end block  236  is mounted parallel to the front shuttle pivot plate  238  via a thumbscrew  242  having an adjustment knob  240 . A compression spring  244  is received onto the shaft of the thumbscrew  242  after it passes through the end block  236 , and the thumbscrew  242  is thereafter received into a threaded opening in the front shuttle pivot plate  238 . Preferably, at least two shoulder screws  246  are slidably received within the end block  236  at one end and are fixedly coupled at the other end to the front shuttle pivot plate  238  to help maintain the position of the end block  236  with respect to the front shuttle pivot plate  238 . 
     Referring back to  FIG. 5 , the auto-feed apparatus  102  further includes a push rod assembly  252 . The push rod assembly  252  includes a longitudinal push rod  254  that is receivable within the shuttle  210 . The forward end of the push rod  254  is slidably received within the shuttle  210 , and the rear end of the push rod  254  is coupled to a horizontal main shuttle bracket  258  through a push rod spacer  256 . The rear portion of the main shuttle bracket  258  is coupled to the top of a runner block  264  with upper and lower shuttle rail spacers  260  and  262  disposed therebetween. The runner block  264  is slidably received on a guide rail  266 , and the guide rail  266  is mounted lengthwise along the mount plate  120  laterally of the shuttle  210 . 
     Referring specifically to  FIG. 3 , the push rod assembly  252  further includes a push rod drive assembly  270  coupled to the mount plate  120  laterally of the guide rail  266 . The push rod drive assembly  270  includes a first pulley  272  and a second pulley  274  journaled for rotation on the mount plate  120  and interconnected by a timing belt  278 . The first timing pulley  272  is operably coupled to a stepper motor  280  that is mounted to the lower surface of the mount plate  120 . 
     The push rod drive belt assembly  270  is actuated to reciprocate the push rod  254  linearly within the shuttle  210 . The shuttle rail upper spacer  260  is coupled to the belt drive  270  through a shuttle belt clamp  268 . When the timing belt  278  is translated in either a clockwise or counterclockwise direction, the shuttle rail upper spacer  260  necessarily moves along with the belt  278 , thereby translating the lower spacer  262  and the main shuttle bracket  258  linearly on the runner block  264  along the path defined by the guide rail  266 . The linear translation of the main shuttle bracket  258  linearly translates the push rod  254  within the shuttle  210 . 
     Still referring to  FIG. 3 , the auto-feed apparatus  102  further includes a clamp assembly  284  that raises and lowers a clamp  302  above the forward end of the shuttle  210 . The clamp assembly  284  includes a solenoid mount bracket  286  that is positioned above the push rod drive belt assembly  271  and is coupled at its rear end to the shuttle  210  through a solenoid mount spacer  287  that extends therebetween. A rotary solenoid  288  is disposed between the solenoid mount bracket  286  and the shuttle  210 . The rotary solenoid  288  is coupled to the interior surface of the solenoid mount bracket  286 , and a rotary output arm  289  of the rotary solenoid  288  extends through an opening in the solenoid mount bracket  286 . 
     A clamp arm  290  is operably coupled to the rotary output arm  289  of the rotary solenoid  288  and is positioned adjacent to the exterior surface of the solenoid mount bracket  286 . The clamp arm  290  is coupled at one end to the rotary output arm  289  and extends outwardly and forwardly therefrom. The rotary solenoid  288  rotationally translates the clamp arm  290  about the axis defined by the output arm  289 . 
     The second end of the clamp arm  290  is pivotally coupled to a first end of a clamp connector arm  292  that extends substantially vertically therefrom. The clamp connector arm  292  is pivotally coupled at its second end to the side of a clamp spacer  294 , and the rear surface of the clamp spacer  294  is mounted to the top of a runner block  300 . The runner block  300  is slidably received on a vertical guide rail  298  that is mounted to a vertical clamp rail mount  296 . The clamp rail mount  296  is coupled to the interior surface of the solenoid mount bracket  286  on one side and to the exterior surface of the shuttle  210  on the other side. 
     A clamp  302  is mounted to the front surface of the clamp spacer  294 . The clamp  302  extends outwardly from the spacer  294  so that it is positioned over the forward end of the shuttle  210 . The clamp  302  is engageable with a container  103  when the clamp  103  is lowered down within the shuttle  210 . 
     In operation, the rotary solenoid  288  is actuated to rotatably translate the clamp arm  290  in a clockwise or counterclockwise direction about the axis of the rotary output arm  289 . In this manner, the clamp arm  290  thereby vertically translates the clamp connector arm  292 , the clamp spacer  294 , and the runner block  300  along the guide rail  298 . The vertical translation of the clamp spacer  294  along the path defined by the guide rail  298  raises and lowers the clamp  302 . 
     One end of an extension spring  282  is mounted to the solenoid mount bracket  286  and the other end is coupled to the main shuttle bracket  258 . The spring  282  biases the clamp assembly  284  and the shuttle  210  (which are coupled together through the solenoid mount spacer  287  and the clamp rail mount  296 ) rearwardly toward the main shuttle bracket  258  of the pushrod drive assembly  252 . 
     The auto-feed apparatus  102  and the labeling apparatus  100  share the same programmable logic controller (PLC) for controlling the automatic sequence of operations of each apparatus. The PLC receives digital input signals from a control panel (not shown) and a plurality of sensors mounted within each apparatus  102  and  100 . 
     Referring to  FIG. 2 , a door closed sensor  326  is mounted to the infeed table  106  adjacent to the end of the feed channel  118 . The door closed sensor  326  is OFF when the gate  119  is open and the door closed sensor  326  is ON when the gate  119  is closed. A feed sensor  324  is mounted to the infeed table  106  along the second bottom edge  133  within the drive housing  140 . The feed sensor  324  senses whether a container  103  is adjacent to the door  119  and in position to be dropped down into the shuttle  210 . If a container  103  is present, the feed sensor  324  is ON, and if a container  103  is not present, the feed sensor  324  is OFF. 
     Referring to  FIG. 5 , first, second, and third proximity switches  308 ,  310 , and  312  are mounted to the mount plate  120 . Preferably, inductive proximity switches or optical sensors are used; however, other switches may also be used without departing from the spirit and scope of the present disclosure. The first proximity switch, or pushrod back sensor  308  is positioned on the mount plate  120  below the shuttle rail upper spacer  260 . The shuttle rail upper spacer  260  consists of a conductive material, such as steel, brass, aluminum, etc., that is detectable by the pushrod back sensor  308 . The first proximity switch  308  detects the shuttle rail upper spacer  260  when the pushrod  254  is retracted within the shuttle  210 . The pushrod back sensor  308  is ON when the pushrod  254  is retracted, and the pushrod back sensor  308  is OFF when the pushrod has been extended forward within the shuttle  210 . 
     The second proximity switch, or shuttle home sensor  310  is positioned below the rear end of the shuttle  210 . A shuttle back flag  314  is secured to the underside of the shuttle  210  at its rear end. The shuttle back flag  314  is also made of a conductive material such that it is detectable by the shuttle home sensor  310 . The shuttle home sensor  310  is ON when the shuttle back flag  314  is detected and the shuttle home sensor  310  is OFF when the shuttle back flag  314  is not detected. 
     Referring to  FIG. 3 , the third proximity switch, or end shuttle travel sensor  312  is mounted on the mount plate  120  at its forward end on the side of the mount plate  120  having the push rod drive assembly  270 . The end shuttle travel sensor  312  is positioned on the mount plate  120  along substantially the same linear path as the guide rail  266 . The clamp rail mount  296 , which is positioned above the guide rail  266 , is sensed by the end shuttle travel sensor  312  when the clamp assembly  284  is translated forward along with the shuttle  210 . The clamp rail mount  296  consists of a conductive material such that it may be sensed by the end shuttle travel sensor  312 . The end shuttle travel sensor  312  is ON when the clamp rail mount  296  is detected, and the end shuttle travel sensor  312  is OFF when it is not detected. 
     Referring to  FIG. 6 , a full tray sensor  318  is positioned below the mount plate  120  to sense when the tray  134  is filled with containers  103 . When the tray  134  is full, the tray sensor  318  is ON, and when the tray  134  is not full, the tray sensor  318  is OFF. 
     To use the auto-feed apparatus  102 , the auto-feed device  102  is first adjusted to fit the containers  103  that are to be fed into the labeling apparatus  100 . Referring to  FIGS. 7A and 7B , the adjustment mechanism  156  is used to simultaneously reposition the retention device  172  within the infeed channel  118  and to change the width of the infeed channel  118 . To make the adjustments, two containers  103  are placed within the infeed channel  118 . The adjustment knob  158  is turned counterclockwise until the singulator top cover  110  is no longer clamped between the thumbscrew shoulder and the spacer  160 . Thereafter, the adjustment knob  158  is slidably translated within the longitudinal slot of the singulator top cover  110 . Since the retention device  172  is indirectly coupled to the adjustment knob  158 , the retention device  172  moves along the same path as the knob  158 . The adjustment knob  158  is translated within the slot until the retention device  172  engages the second container  103  in the feed channel  118 . 
     The linear movement of the adjustment knob  158  linearly translates the front cover  108  of the singulator housing  155 . The shortened portion of the front cover  108  is held in tension against the forward edges of the retention device bracket  166  and the retention device guide  174 . Therefore, the linear movement of the retention device bracket  166  and the retention device guide  174  (through the adjustment knob  158 ) translates the front cover  108  along the guide rail  180 . The linear movement of the front cover  108  changes the orthogonal position of the shortened portion of the front cover  108  relative to the second straight edge  133  to increase or decrease the width of the feed channel  118 . The width of the feed channel  118  needs to be adjusted so that smaller containers  103  will not enter the feed channel  118  side by side and so that larger containers  103  can fit within the feed channel  118 . 
     The end stop  234  is also adjusted so that a container  103  may be properly aligned within the shuttle  210  and delivered to the labeling apparatus  100  for labeling. Referring to  FIG. 8B , a container  103  is placed within the forward end of the shuttle  210 . Thereafter, the adjustment knob  240  is torqued to either drive or loosen the thumb screw  242  within the front shuttle pivot plate  238  and thereby translate the end block  236  closer to or further away from the front shuttle pivot plate  238 . The end block  236  is translated by the adjustment knob  240  until the back surface of the end block  236  abuts the cap of the container  103  and the container shoulder  107  aligns the front surface of the front shuttle pivot plate  238 . At this point, the shuttle  210  has been adjusted to receive the container  103 . 
     The general operation of the auto-feed apparatus  102  will be hereinafter described with reference to the sequence of operation set forth in  FIG. 9 . First, the auto-feed apparatus  102  is activated, as indicated by block  400 . A plurality of containers  103  of generally the same size are loaded onto the infeed table  106 . The containers  103  are gravitationally forced downwardly toward the feed channel  118 . The timing belt  146  also engages the containers  103  and urges the containers  103  downwardly toward the feed channel  118 , thereby preventing the clogging or bridging of containers  103 , as indicated by block  402 . 
     When a container  103  is sensed by the feed sensor  324 , as indicated by decision block  404 , the retention device  172  is actuated to engage the second container  103 , as indicated by block  406 . The retention device  172  retains the second container  103  within the feed channel  118  and isolates the first container from the remaining containers  103 . The pushrod  254  is then translated rearwardly away from the shuttle  210  by the pushrod assembly  252  to open the gate  119 , as indicated by block  408 . With the gate  119  open, the first container  103  in the feed channel  118  is deposited into the shuttle  210 , as shown in  FIG. 7A . 
     After the container  103  is dropped down into the shuttle  210 , the pushrod  254  is translated forwardly within the shuttle  210  to close the gate  119 , as indicated by block  410 . As the gate  119  closes, the shuttle flap  204  engages the body of the container  103  to stabilize the container  103  within the shuttle  210 , as shown in  FIG. 3 . Once the gate  119  is closed, the retention device  172  is retracted and the second container  103  falls downwardly against the gate  119 , as indicated by block  412 . A new second container  103  falls in line behind the new first container  103 , and the retention device  172  engages the new second container  103  to maintain its position within the feed channel  118 . The process of depositing one container  103  into the shuttle  210  is repeated when the shuttle  210  is ready for another container  103 . 
     Referring to  FIG. 7B , the pushrod  254  continues to translate forwardly within the shuttle  210  and engages the bottom of the container  103 , as indicated by block  414 . The pushrod  254  translates the container  103  forwardly within the shuttle  210  until the cap of the container  103  abuts the end block  236 , as indicated by decision block  416 . When the container  103  is engages the end block  236 , the clamp assembly  284  is activated to drop the clamp  302  down to engage the body of the container  103  to secure the container  103  within the shuttle  210 , as shown in  FIG. 8A  and indicated by block  418 . As the pushrod  254  continues to translate forwardly, as indicated by block  420 , it also translates the shuttle  210 , the container  103 , the clamp assembly  284 , the end block  234 , and the rotator cam  224  forwardly together as one unit. 
     Referring to  FIG. 8B , the rotator cam  224  travels forwardly along the rotation cam path plate  216  through the translation of the roller bearing  217  along the cam surface  219 . The rotator cam  224  continues to travel along the cam surface  219  until the end of the stem  225 , which houses the end of the thru-rod  230 , drops into the divot  221 . As the stem  225  and thru-rod  230  drop down into the divot  221 , the weighted portions  226  and  228  of the rotator cam  224  drive the rotator cam  224  in a clockwise direction about the center axis of the thru-rod  230 . This clockwise rotation of the rotator cam  224  also drives the clockwise rotation of the end block  234  about the center axis of the thru-rod  230 . Although the end block  234  is no longer abutting the end of the container  103 , the container  103  is held within the shuttle  210  by the clamp arm  302 . Thus, the pushrod  254  continues to drive the shuttle  210 , the container  103 , the clamp assembly  284 , the reciprocated end block  234 , and the rotator cam  224  forward together as one unit. 
     Referring to  FIG. 8C , as the rotator cam  224  continues to travel forward along the rotator cam path plate  216 , the stem  225  is lifted out of the divot  221  by the clockwise rotation of the rotator cam  224 . The rotator cam  224  rotates approximately 180 degrees about the center axis of the thru-rod  230  such that the end block  284  is maintained beneath the shuttle  210  in an overturned position. 
     The pushrod  254  continues to drive the shuttle  210 , the container  103 , the clamp assembly  284 , the reciprocated end block  234 , and the rotator cam  224  forward together as one unit until the rotator cam  224  abuts the lip  223  on the end of the cam path  219 . At this point, the end shuttle travel sensor  312  is ON, as indicated by decision block  422 , and the pushrod drive assembly  252  stops actuating the pushrod  254 , as indicated by block  424 . The container  103  is positioned within the labeling apparatus  100  so that a label  350  may be wrapped around the container  103 , as shown in  FIG. 8C . As discussed in more detail in U.S. Patent Application Publication No. US 2005/0115681 A1, a label  350  is applied to the container  103 , as shown in  FIGS. 8C and 8D , and the labeling apparatus  100  sends a container wrap signal, as indicated by decision block  426 . 
     As the label  350  is being secured to the container  103 , the clamp assembly  284  lifts the clamp arm  302  to release the container  103 , as shown in  FIG. 8D  and as indicated by block  428 . The pushrod  254  is translated rearwardly by the pushrod drive assembly  252 , as shown in  FIG. 8E  and as indicated by block  430 . As the pushrod  254  is translated rearwardly, the shuttle  210  and clamp assembly  284  are pulled rearwardly by the extension spring  282 . The container  103  is released from the labeling apparatus  100  and is dropped downwardly into the tray  234 . 
     The rearward movement of the shuttle  210  causes the rotator cam  224  to travel rearwardly along the cam path  219 . When the stem  225  enters the divot  221 , the rotator cam  224  rotates counterclockwise about the center axis of the thru-rod  230 , thereby rotating the thru-rod  230  and the end block  234  counterclockwise until the end block  234  abuts the front edge of the shuttle  210 . Once the pushrod  254 , the shuttle  210 , the clamp assembly  284 , the rotator cam  224 , and the end block  234  are restored to their original positions, the shuttle  210  is ready to receive another container  103  so that the feeding process may be repeated. 
     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.