FIELD OF THE INVENTION 
     The present invention relates generally to the field of processing and packaging consumer products, particularly in the pharmaceutical industry. More specifically, the present invention relates to an apparatus and method for applying a label to a container, such as a vial for pharmaceuticals. 
     BACKGROUND 
     The use of automated labeling systems for packaging pharmaceutical products, such as pill vials, is known in the art. Examples of such systems include U.S. Pat. No. 6,308,494 B1 to Yuyama et al., U.S. Pat. No. 6,036,812 to Williams et al., and U.S. Pat. No. 5,798,020 to Coughlin et al. In a typical system, a vial is placed into a labeler and held in place by a gripping mechanism. As the vial is rotated, a label is applied to the vial and the vial is removed from the labeler. 
     Prior art labeling systems use various types of gripping mechanisms to secure the vial while a label is being applied. The prior art gripping mechanisms, however, do not easily adapt to handle vials having different diameters. For example, a system set up to place labels on vials with a small diameter cannot easily be converted to place labels on vials with a larger diameter. In typical prior art labeling systems, the labeling process must be halted and a different sized gripping mechanism substituted to accommodate a vials of different diameters. Furthermore, even if the gripping mechanism is capable of accommodating different sized vials, alignment problems (i.e., alignment of the label relative to the vial) are often encountered. Also, vials of different height cannot be labeled in the preferred method which is near the vial opening. 
     Thus, a need exists for a labeling system having a vial gripping mechanism that can accommodate different sized vials without requiring changes in hardware. Additionally, a need exists for a labeling system that enables labels to be accurately aligned in the preferred location on a vial, regardless of the vial&#39;s size. 
     SUMMARY 
     One embodiment of the present invention is directed to a chuck assembly comprising a housing defining a longitudinal axis and having a first end. A plurality of pins extend substantially parallel with the axis from the first end. The plurality of pins is located at a first radius relative to the axis with at least one of the pins being operable to move from the first radius to a second radius, relative to the axis. The pins move from the first radius to the second radius without exposing a cavity on or within the chuck assembly. A means for moving the at least one pin between the first radius and the second radius is also provided. The means for moving may comprise any known combination of gears, cams, and other mechanical components for imparting the desired motion to the pins. 
     The chuck assembly of the present invention may be used in combination with various other components. For example, the chuck assembly may be used in a container labeling system comprising a printer stand, a label printer, a vial drive assembly, a stand assembly, and the chuck assembly. 
     The present invention is also directed to a method for labeling a container comprising placing a container on a gripping mechanism having a plurality of movable gripping pins for inserting into the container. The gripping mechanism is activated to engage the container with the gripping pins. The container is brought into engagement with a source of labels and a label is applied to the container. The container is taken out of engagement with the source of labels and the gripping mechanism is deactivated to disengage the gripping pins from the container. 
     The present invention enables vials of various diameters to be handled by a single device without the need to change hardware. The present invention also enables labels to be uniformly placed on vials of different lengths. Those advantages and benefits, and others, will be apparent from the Detailed Description appearing below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To enable the present invention to be easily understood and readily practiced, the present invention will now be described, for purposes of illustration and not limitation, in connection with the following figures wherein: 
     FIG. 1 is a perspective view of a chuck assembly for gripping containers of various diameters according to an embodiment of the present invention. 
     FIG. 2 is a front view of the chuck assembly of FIG. 1 with the chuck pins in a disengaged position according to an embodiment of the present invention. 
     FIG. 3 is a front view of the chuck assembly of FIG. 1 with the chuck pins in an engaged position according to an embodiment of the present invention. 
     FIG. 4 is a detailed view of the internal components of the chuck assembly of FIG. 1 according to an embodiment of the present invention. 
     FIG. 5 is a front view of a chuck stand assembly for mounting the chuck assembly of FIG. 1 according to an embodiment of the present invention. 
     FIG. 6 is a rear view of the chuck stand assembly of FIG. 5 according to an embodiment of the present invention. 
     FIG. 7 is a perspective view of a labeling system incorporating the chuck stand assembly of FIG. 5 according to an embodiment of the present invention. 
     FIG. 8 is a top view of the labeling system of FIG. 7 according to an embodiment of the present invention. 
     FIG. 9 is an operational process for gripping a container according to an embodiment of the present invention. 
     FIG. 10 illustrates the alignment of a label relative to a vial having a first length secured by the chuck assembly of FIG. 1 according to an embodiment of the present invention. 
     FIG. 11 illustrates the alignment of a label relative to a vial having a second length secured by the chuck assembly of FIG. 1 according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a perspective view of a chuck assembly  10  for gripping containers of various diameters according to an embodiment of the present invention. Chuck assembly  10  is a gripping mechanism that is used to secure and transport a container, for example, to and from a station where a label is applied. The chuck assembly  10  is comprised of a chuck body  12 , which is a housing for the various parts of chuck assembly  10 . Chuck assembly  10  has one or more chuck pins  34  extending from a first end  13  of the chuck body  12 . The chuck pins  34  extend substantially parallel with a longitudinal axis of the chuck body  12 , which may be a central axis. Each chuck pin  34  may have a roller sleeve  36  associated therewith. In the current embodiment, each chuck pin  34  is attached to a cam shaft  26  housed within the chuck body  12 . Each cam shaft  26  may be rotated by a single drive shaft  16  which enters the chuck body  12  from a second end  15 . 
     As illustrated in FIG. 1, each pin  34  may be rotated by its associated cam shaft  26  without exposing the interior housing of the chuck body  12  and without creating a cavity relative the chuck body  12 , the cam shafts  26 , and the chuck pins  34 , among others. Thus, the chuck assembly of the present invention prevents contaminants from entering the chuck body or restricting the rotation of the cam shaft  26  and chuck pins  34 . 
     FIGS. 2 and 3 are front views of the chuck assembly  10  illustrated in FIG.  1 . FIGS. 2 and 3 illustrate the chuck pins  34  in a disengaged position and in an engaged position, respectively, according to an embodiment of the present invention. The outer edges of chuck pins  34  are positioned at a first radius relative to a point  17  laying along the longitudinal axis of the chuck body  12 . In the current embodiment, each chuck pin  34  is attached near an outer edge of its respective cam shaft  26 , so that when cam shafts  26  are rotated, the radius measured from the chuck pins  34  to the point  17  is changed. In the disengaged position (as illustrated in FIG.  2 ), the outer edges of the chuck pins  34  are at a first radius  38 . The disengaged position refers to a position in which the chuck pins  34  are not securing a container, such as a vial, that is placed over the chuck pins  34 . In the engaged position (as illustrated in FIG.  3 ), the outer edges of the chuck pins  34  are at a second radius  39 ; the second radius  39  being larger than the first radius  38 . The engaged position refers to a position in which the chuck pins  34  secure a container, such as a vial, that is placed over the chuck pins  34 . 
     In the current embodiment, the chuck pins  34  begin in the disengaged position (i.e., positioned at the first radius  38 ). A vial (not shown) is loosely placed over the chuck pins  34  and pushed towards the chuck body  12  such that the vial comes in contact with the chuck body  12 . Once the vial is in place, the drive shaft  16  is rotated, causing each cam shaft  26  to rotate in, for example, a counter-clockwise direction. The drive shaft  16  is rotated until the chuck pins  34  engage the vial (i.e., come into contact with the vial&#39;s inner walls). Thus, the second radius  39  (corresponding to the engaged position) is equal to the inner radius of the vial. In the current embodiment, the maximum angular rotation of the cam shafts  26  is limited to 120°. 
     The roller sleeves  36  permit an engaged vial to be rotated by a vial drive motor (not shown in FIGS. 2 and 3) while the vial is engaged by the chuck pins  34  (for example, while a label is being placed on the vial). After a label is placed on the vial, the drive shaft  16  is rotated in the opposite direction causing the cam shaft  26  to rotate in the clockwise direction. The rotating cam shafts  26 , in turn, cause the chuck pins  34  to disengage the vial (i.e., to travel from the second radius  39  to the first radius  38 ). The labeled vial is then removed from the chuck pins  34 . 
     It should be noted that the rotational direction used to engage and disengage a vial may be reversed (i.e., clockwise to engage, counter-clockwise to disengage) and/or mixed (i.e., one cam shaft  26  rotating clockwise with another cam shaft  26  rotating counter-clockwise) while remaining within the scope of the present invention. It should further be noted that the present invention is not intended to limit the chuck pins  34  to a rotational manner of travel. For example in an alternative embodiment, the chuck pins  34  may move radially relative to the point  17 , from the first radius  38  to the second radius  39 . In the alternative embodiment, other components may replace or accompany the drive shaft  16  and cam shafts  26  to effect the linear motion. Furthermore, a shield to eliminate the exposure of a cavity on or within the chuck body (and thus, preventing contaminants from entering the chuck body), may be associated with each pin  34 . 
     FIG. 4 is a detailed view of the internal components of the chuck assembly  10  of FIG. 1 according to one embodiment of the present invention. As illustrated in FIG. 4, each chuck pin  34  is attached to one end of its respective cam shaft  26 . A cam shaft spur gear  28  is carried between a pair of cam shaft needle bearings  32 , all of which are secured to the cam shaft  26  by a cam shaft retaining ring  30 . In the current embodiment, three chuck pins  34  are used, however, it should be noted that a different number of chuck pins  34  may be used while remaining within the scope of the present invention. 
     The cam shaft spur gears  28  mesh with a drive shaft spur gear  18  carried between and secured to the drive shaft  16  by a pair of drive shaft retaining rings  20 . In the current embodiment, a single drive shaft spur gear  18  is used to mesh with each cam shaft spur gear  28 . It should be noted multiple drive shaft spur gears  18  or multiple drive shafts  16  may be used to rotate the cam shafts  26  while remaining within the scope of the present invention. 
     In the current embodiment, the drive shaft  16 , drive shaft spur gear  18 , cam shafts  26 , and cam shaft spur gears  28  are a means for moving the chuck pins  34  between the first radius and the second radius. It should be noted that alternative means for moving said chuck pins  34  may be used while remaining within the scope of the present invention. For example, a means using one or more pins, linkages, crank arms, jacks, radius bars, screw gears, winches, yokes, connecting rods, levers, toggles, cables, belts, bell cranks, clutches, pulleys, couplings and/or sprockets (among others) may be used while remaining within the scope of the present invention. 
     The drive shaft  16 , drive shaft spur gear  18 , drive shaft retaining rings  20 , cam shafts  26 , cam shaft spur gears  28 , cam shaft retaining rings  30 , and cam shaft needle bearings  32 , among others, are contained with the chuck body  12 . In the current embodiment, the first end  13  of the chuck body  12  has an opening for each chuck pin  34 . The chuck pins  34  extend parallel with a longitudinal axis of the chuck body  12 . The second end  15  of the chuck body  12  is located opposite the first end  13 . An alternating pair of bearing plates  14  and drive shaft needle bearings  22  are attached to the chuck body  12  at the second end  15 . The bearing plates restrain the drive shaft and cam shaft components within the chuck body  12 , whereas the drive shaft needle bearings  22  allow the drive shaft  16  to freely rotate while passing through bearing plates  14 . A prime mover (such as a rotary solenoid, electric motor, pneumatic piston, hydraulic piston, among others)(not shown in FIG. 4) is a device that is coupled to and imparts the necessary force to the means for moving the chuck pins  34 . 
     In the current embodiment, a rotary solenoid  46  is used as the prime mover to impart a rotational force on the drive shaft  16 . One of the advantages of using a rotary solenoid is the limited torque produced by the rotary solenoid. For example, the rotary solenoid may be selected so as to provide a known torque for rotating shaft  16 , and thus rotating cam shafts  26  from a minimum radius to a maximum radius. If a vial having a radius somewhere between the minimum and maximum is placed on the chuck assembly  10 , sufficient torque will be generated to rotate cam shafts  26  to bring chuck pins  34  into engagement with the inner wall of the vial. However, resistance caused by contact between the chuck pins  34  and the inner wall of the vial will be sufficient to cease movement of the cam shafts  26  and drive shaft  16  without damaging the rotary solenoid. Furthermore, the rotary solenoid does not provide sufficient torque to damage the vial. 
     FIGS. 5 and 6 are a front view and a back view, respectively, of a chuck stand assembly  40  for mounting the chuck assembly  10  of FIG. 1 according to an embodiment of the present invention. Chuck stand assembly  40  includes a chuck assembly mounting plate  42  for mounting the chuck assembly  10 . The chuck assembly mounting plate  42  is also used to mount and align a hub brake  50 , brake release  52 , rotary solenoid  46 , and flexible coupling  48  with the chuck assembly  10 . The chuck assembly mounting plate  42  is coupled to a slide mount bracket  60  with screws  59 . A linear bearing  58 , attached to a slide mount bracket  60  and having a compression spring  56  housed within a spring pocket  54 , permits the horizontal position of the chuck assembly mounting plate  42  to be adjusted. 
     In the current embodiment, a preferred horizontal position is set such that the smallest diameter vial to be labeled will be pressed against the vial drive assembly  76  (as discussed in more detail in conjunction with FIG.  8 ). By setting the chuck assembly mounting plate  42  in this position, the labeler system  70  can accommodate larger vials without changing hardware. Specifically, when a larger vial (secured by the chuck assembly  10 ) is placed against the vial drive assembly  76 , the compression spring  56  permits the chuck assembly mounting plate  42  to move horizontally to accommodate the larger vial. It should be noted that other horizontal adjustment means for the chuck assembly mounting plate  42  may be used while remaining within the scope of the present invention. For example, an actuator may be used for adjusting the position of the chuck assembly mounting plate  42 . 
     The slide mount bracket  60  is attached to an actuator  66 , which is driven by a stepper motor  62 . The actuator  66  permits the vertical position of the combination of the slide mount bracket  60  and chuck assembly  10  to be adjusted. In the current embodiment, a linear ball screw actuator  66  is used. It should be noted that other types of actuators and motors may be used while remaining within the scope of the present invention. It should further be noted that chuck stand assembly  40  of the present invention is not intended to be limited to the chuck assembly  10  described above. Other types of electric chuck assemblies such as those manufactured by Sommer Automatic (e.g., Electric 3-Jaw Grippers catalog numbers GED1302, GED1306, GED1502, and GED1506) and Robohand (e.g., RPZ Electric Gripper), among others, may be used with the chuck stand assembly  40  while remaining within the scope of the present invention. 
     FIGS. 7 and 8 illustrate a labeling system  70  incorporating the chuck stand assembly of FIG. 5 according to an embodiment of the present invention. FIG. 7 is a perspective view, and FIG. 8 is a top view of the labeling system  70 . 
     Labeling system  70  includes a printer stand  72 , label printer  74 , chuck stand assembly  40  (with chuck assembly  10 ), a vial drive assembly  76 , and vial drive mount bracket  78 . The printer stand  72  supports label printer  74 , chuck stand assembly  40 , and vial drive mount bracket  78 . Vial drive assembly  76  includes a vial drive motor (not shown) and a vial drum (not shown). In the current embodiment, a roll of labels is fitted over the vial drum, the labels are placed in contact with a vial and the vial drive motor rotates the labels, and thus, the vial. 
     As best illustrated in FIG. 8, the labeling system  70  is configured such that a vial (not shown), which is secured by the chuck assembly  10 , is aligned with and comes into contact with a printed label  80 . In the current embodiment, the labeling system  70  operates in the following manner. The actuator  66  is raised by the stepper motor  62  such that the chuck assembly  10  moves away from the vial drive assembly  76  to a vial exchange position. The chuck pins  34  are reset to the disengaged position. A vial is then placed over the chuck pins  34 . For example, a robot arm from a prescription filling station may be used to place the vial over the chuck pins  34 . One example of a prescription filling station with which the labeling system  70  may be used is shown in U.S. Pat. No. 6,006,946, which is hereby incorporated by reference. The brake release  52  is activated to release hub brake  50 , thus allowing the drive shaft  16  to rotate. The rotary solenoid  46  is then activated to move the chuck pins  34  to the engaged position. Once the chuck pins  34  reach the engaged position, the rotary solenoid  46  begins to “torque out” and the hub release  52  is deactivated. When the hub release  52  is deactivated, the hub brake  50  prevents the drive shaft  16  from rotating, and thus locks the chuck pins  34  in the engaged position. Once the hub brake  50  locks the drive shaft  16  in position, the rotary solenoid  46  is deactivated. 
     The actuator  66  of the chuck stand assembly  40  is then lowered by the stepper motor  62  until the vial comes into contact with the vial drive assembly  76 . The compression spring  76  permits the chuck assembly mounting plate to slightly move in the horizontal direction as required to help facilitate vials of different radii. Printer  74  prints the desired information onto a label  80 . The vial drive assembly  76  simultaneously rotates and applies the printed label to the vial. After the printed label is applied to the vial, the actuator  66  is raised by the stepper motor  62  until the chuck assembly  10  reaches the vial exchange position. The brake release  52  is then activated and the hub brake  50  releases the drive shaft  16 . The chuck pins  34  are then returned to the disengaged position. The vial is removed from the chuck pins  34  (for example, using the prescription filling station&#39;s robot arm). The next vial to be labeled may then be placed over the chuck pins  34 . 
     It should be noted that the operation of the brake release  52  and hub brake  50  may be altered while remaining within the scope of the present invention. For example, the brake release  52  may be activated to engage the hub brake  50  and deactivated to release the hub brake  50 . Additionally, the hub brake  50  may prevent the movement of another means for moving (for example, a cam shaft  26 ) the chuck pins  34  while remaining within the scope of the present invention. Furthermore, the brake release  52  and hub brake  50  may be combined into a single unit. 
     As discussed above in conjunction with FIGS. 5 and 6, other types of electric chuck assemblies such as those manufactured by Sommer Automatic (e.g., Electric 3-Jaw Grippers catalog numbers GED1302, GED1306, GED1502, and GED1506) and Robohand (e.g., RPZ Electric Gripper), among others, may be used with the chuck stand assembly  40  while remaining within the scope of the present invention. 
     FIG. 9 is an operational process  90  for gripping a container according to an embodiment of the present invention. Operation  91  initiates operational process  90  when a container is placed over the chuck pins  34  of the chuck assembly  10 . In the current embodiment, the container is a vial. The vial is pushed over the chuck pins  34  (which are in the disengaged position) until the vial comes into contact with the chuck body  12 . 
     Operation  92  assumes control after operation  91  initiates operational process  90 . In operation  92 , the hub brake  50  is released, thus allowing drive shaft  16  to rotate. In the current embodiment, hub brake  50  is released when brake release  52  is activated. After the hub brake  50  is released, operation  93  assumes control. 
     In operation  93 , the rotary solenoid  46  is activated causing the chuck pins  34  to engage the interior surface of the vial. In the current embodiment, the rotary solenoid rotates drive shaft  16  having drive shaft spur gear  18  that is meshed with one or more cam shaft spur gears  28 . Each of the cam shaft spur gears  28  causes its respective cam shaft  26  to rotate, which in turn causes its associated chuck pin  34  attached at the end of the cam shaft  26  to move from the first radius  38  to the second radius  39  relative to the point  17 . After the rotary solenoid is activated by operation  93 , operation  94  assumes control. 
     Operation  94  engages the hub brake  50  when the rotary solenoid  46  begins to “torque out”. In the current embodiment, the rotary solenoid begins to torque out when the chuck pins  34  come into contact with the inner walls of the vial. The hub release  52  is deactivated causing the hub brake  50  to engage the drive shaft  16 . When engaged, the hub brake  50  prevents the drive shaft  16  from rotating. After operation  94  engages the hub brake, operation  95  assumes control. 
     Operation  95  deactivates the rotary solenoid  46 . When the rotary solenoid is deactivated, the chuck pins  34  remain in the engaged position because the drive shaft  16  is locked in place by the hub brake  50 . The vial remains engaged until the hub brake  50  is released. The vial is now ready to be transported. Transportation in this case means to bring the vial into engagement with a source of labels. In other contexts, the vial might be transported to other types of workstations, e.g., a capping station. After the vial has been labeled, i.e., the work station has performed its function, the vial is transported back to the vial exchange position. In the embodiment shown, transporting the vial is accomplished by the stepper motor  62 , although other means of transport may be provided. 
     After the vial returns to the vial exchange position, operation  96  releases the hub brake  50  and allows the chuck pins  34  to return to the disengaged position. In the current embodiment, the brake release  52  is activated to release the hub brake  50  and the chuck pins  34  automatically disengage the vial (for example, through the use of springs, the built-in tensioning of the cam shafts, etc.). 
     Operation  97  terminates operational process  90 . After the vial is disengaged by operation  96 , the vial may be removed and operational process  90  repeated with another vial. 
     FIGS. 10 and 11 illustrates the alignment of a label  80  relative to vials  82 ,  83 , respectively, secured by the chuck assembly  10  of FIG. 1 according to an embodiment of the present invention. In FIG. 10, vial  82  has a length “Y.” In FIG. 11, vial  83  has a length “Z,” where length Z is greater than length Y. Vials  82 ,  83  each have a set of threads  84  for securing a cap (not shown) to the vials. As illustrated in FIGS. 10 and 11, the distance (denoted “X”) from the first end  13  of chuck body  12  to an upper edge of label  80  is constant. Thus as long as the threaded ends of vials  82 ,  83  are touching the first end  13  of chuck assembly  12  when the chuck pins  34  secure the vial, the alignment of the label  80  will be constant regardless of the length of the vial  82 ,  83 . 
     The above-described embodiments of the invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims. For example in an alternative embodiment, a gripping mechanism employing one or more stationary chuck pins  34  in combination with at least one movable chuck pin  34  is used.
A chuck assembly comprises a housing defining a longitudinal axis and having a first end. A plurality of pins extend substantially parallel with the axis from the first end. The plurality of pins is located at a first radius relative to the axis. At least one of the pins is operable to move from the first radius to a second radius, relative to the axis. The chuck assembly also includes a means for moving at least one pin between the first radius and the second radius. A prime mover provides the necessary drive to the means for moving. The chuck assembly may be used in combination with various other components to form combinations or systems. A method of labeling a container is also disclosed.