Abstract:
A radio frequency identification (RFID) label applicator comprising a label web path having a bend, the bend having an apex and a label-separating/label-retaining portion having an extendable acute label-separating edge, the path being directed about the portion at the bend so that the edge forms the apex of the bend into an acute apex when the edge is substantially extended, and when the edge is substantially retracted the apex is obtuse.

Description:
[0001]     This application claims priority from provisional patent application Ser. No. 60/654,274, filed Feb. 18, 2005, the disclosure of which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Radio frequency identification (RFID) tags have recently become a preferred means of automatic identification as costs of production have declined. RFID tags store user-defined information and transmit that information to a reader, or data processor, via radio frequency (RF) waves. RFID tags may also allow the reader/processor to write new information thereto. Active RFID tags generally comprise a programmable microchip, an antenna, and a power source. Passive RFID tags do not contain an internal power source, and instead rely on RF (electromagnetic) waves sent from the reader/processor for power. The microchip stores data, while the antenna receives and transmits data as RF waves.  
         [0003]     RFID labels contain RFID tags, in addition to having an exterior surface for receiving visible or printed markings. Therefore, RFID labels contain two forms of information, the RFID tag and the label surface. Within the label applicator industry, the use of RFID labels has created new problems. One of these problems is how to effectively perform read/write cycles on specified RFID labels efficiently and without adversely affecting other RFID labels. A second problem is how to reject defective RFID labels without significantly delaying label application cycles. The present invention at least provides a novel solution to these problems.  
       SUMMARY OF THE INVENTION  
       [0004]     In one embodiment, the invention comprises a radio frequency identification (RFID) label applicator, comprising: a label-separating/label-restraining portion having an acute label-separating edge; a label web path having a label separating/retaining bend, the bend being directed about the label-separating/label-restraining portion; wherein the edge is translatable between a first position and a second position such that when the edge is in the first position the bend is directed about the portion in an acute course, and when the edge is in the second position the label web path is directed about the portion in a obtuse course.  
         [0005]     In another embodiment, the invention comprises a radio frequency identification (RFID) label applicator, comprising: a label-separating/label-restraining portion having an acute label-separating edge and an obtuse label-retaining surface; a label web path having a label separating/retaining bend, the bend being directed about the label-separating/label-restraining portion; wherein one of the edge and surface is translatable between a first and second position such that when the one of the edge and surface is in the first position the bend is acute and when the one of the edge and surface is in the second position the bend is obtuse.  
         [0006]     In another embodiment, the invention comprises a radio frequency identification (RFID) label applicator, comprising: a label web path having a label separating/retaining bend; means for selectively separating a label from a label web at the bend, the means comprising an acute edge; and means for selectively retaining a label upon the label web at the bend, said retaining means providing an obtuse bend.  
         [0007]     In another embodiment, the invention comprises a method of accepting or rejecting a radio frequency identification (RFID) label in a RFID label applicator, the method comprising the steps of: translating a target label contained upon a label web into a label processing unit, the unit being adjacent a label-separating/label-restraining portion about which the label web travels, where the portion includes an acute label-separating edge that forms an acute bend in the label web as it translates about the portion when the edge is in a label web engaging position, the label web having an obtuse bend about the portion when the edge is in a label web unengaged position; determining whether or not to use the target label; rejecting the target label after determining to not use the label by disengaging the label-separating edge prior to the label translating about the portion so the label web contains the obtuse bend thereabout; accepting the target label after determining to use the label by engaging the acute label-separating edge prior to the label translating about the portion so the label web contains the acute bend thereabout; and translating a portion of the label web adjacent the target label about the edge.  
         [0008]     In another embodiment, the invention comprises a method of accepting or rejecting a radio frequency identification (RFID) label in a RFID label applicator, the method comprising the steps of: translating a target label contained upon a label web into a label processing unit, the unit including a retractable acute label-separating edge about which the label web translates in an acute course, so to generate separation forces between the web and any label translating about the edge capable of separating any label from the web; determining whether or not to use the target label; rejecting the target label after determining to not use the label by retracting the label-separating edge prior to the target label translating about the edge so to reduce the existence of any separation forces that may occur as the target label passes about the edge; accepting the target label after determining to use the label by extending the acute label-separating edge so to generate the necessary separation forces to cause the label to separate from the label web as the web translates about the edge; and translating a portion of the label web adjacent the target label about the edge. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a side view of a label applicator in accordance with a first embodiment of the present invention.  
         [0010]      FIG. 2  is a top view of the label applicator shown in  FIG. 1 .  
         [0011]      FIG. 3  is a side view of a snorkel unit in accordance with the first embodiment of the present invention.  
         [0012]      FIG. 4  is a top view the snorkel unit shown in  FIG. 3 .  
         [0013]      FIG. 5  is a front view of the snorkel unit shown in  FIG. 3 .  
         [0014]      FIG. 6  is a side view of a label processing unit in accordance with the first embodiment of the present invention.  
         [0015]      FIG. 7  is a top view of the label processing unit shown in  FIG. 6 .  
         [0016]      FIG. 8  is a side view showing the snorkel unit in operation.  
         [0017]      FIG. 9  is a side view showing the snorkel unit ejecting a label.  
         [0018]      FIG. 10  is a side view showing the snorkel unit transferring a label to the applicator unit.  
         [0019]      FIG. 11  is a side view showing the snorkel unit and applicator unit in operation. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     In  FIGS. 1 and 2 , a label applicator  10  is shown. Label applicator  10  generally includes the following components: a core unit  11 ; a valve unit  12 ; a supply spool  14 , a tensioning spool array  15 , a retrieval spool  16 , a motor  17 , a read/write unit  18 , and a snorkel unit  20 . Core unit  11  generally houses a controller, connectors to a power source and an air source, and data ports. The valve unit  12  generally provides pneumatic controls for certain label applicator operations, such as label application and rejection via snorkel unit  20 . Supply spool  14  contains a label web  19 , on which includes RFID labels  99  (not shown). Label web  19  travels through tensioning spool array  15 , through snorkel unit  20 , and returns to retrieval spool  16 . Tensioning spool array  15  utilizes existing tensioning technology to ensure proper presentation and translation of label web  19 . Motor  17  facilitates translation of label web  19  through label applicator  10 . Read/write unit  18  communicates with RFID labels  99  via an antenna included within snorkel unit  20  for the purpose of reading from and writing to the RFID labels  99 , verifying operational or active labels  99  and rejecting defective or improper labels  99 , activating passive RFID labels  99 , and storing data. The read/write unit  18  also processes data and/or commands. Read/write unit  18  will reject a RFID label  99  based on user-defined criteria, such as when: the read/write unit  18  fails to receive a response from the RFID label  99 ; the read/write unit  18  fails to receive any transmission from the RFID label  99 ; the RFID label  99  does not contain necessary user-defined information; or the read/write unit is unable to write to the RFID label  99 . Although not necessary, read/write unit  18  transmits RF waves through an antenna at different power levels during read and write cycles because the power required for optimal read cycle performance is different than that required for optimal write cycle performance. Finally, snorkel unit  20  carries out many operations, including communicating with RFID labels  99  via an antenna contained therein, dispersing RFID labels  99  from label web  19  for application to products, applying RFID labels  99  to products, and ejecting rejected RFID labels  99  by failing to disperse the label  99  for product application. Core unit  11 , valve unit  12 , supply spool  14 , tensioning spool array  15 , retrieval spool  16 , and motor  17  utilize technology well-known in the respective art and comprise any commercially available product thereof. Further, the location of all above-mentioned components within label applicator  10  are not critical to the current invention, except that the components must be arranged so that the collective continues to function as a label applicator.  FIGS. 1 and 2  depict one of many possible arrangements of the above-mentioned components.  
         [0021]     Referring to  FIGS. 3 through 5 , snorkel unit  20  includes a snorkel base  22 , label processing unit  30 , and a label applicator unit  70 . Snorkel base  22  provides a surface to mount processing unit  30  and applicator unit  70 . Generally, processing unit  30  provides an antenna unit  54  (not shown) that allows read/write unit  18  to communicate with RFID labels  99 . After communicating with a RFID label  99 , processing unit  30  then either extracts an operational label  99  from label web  19  and delivers it to applicator unit  70  or leaves a rejected label  99  on web  19  for return to retrieval spool  16  (also referred to as label ejection). After receiving an operational label  99 , label applicator unit  70  temporarily retains the label  99  and subsequently transfers the label  99  to any desired product. While label applicator unit  70  is receiving and applying the operational label  99 , a new RFID label  99  is drawn into position below antenna  54 , verified operational or rejected, ejected if verified a rejected label  99 , and, if desired, has data written thereto. Thus, the new RFID label  99  may be ready for delivery to applicator unit  70  immediately after applicator unit  70  applies the previously transferred label  99  to the product, depending on the user-defined operations to be performed on the new RFID label  99  by the read/write unit  18 . By allowing the read/write unit  18  to operate on a label  99  while another is being applied to a product, the time extending between label applications is reduced.  
         [0022]     The label processing unit  30  includes an ejector slide unit  32 , a spring block unit  40 , an antenna unit  50 , and a peel unit  60 . Ejector slide unit  32  provides a sliding mounting portion  34  that translates, thereby allowing a portion of the peel unit  60  to retract and eject a rejected label  99 . Ejection allows a rejected label  99  to remain on label web  19  as it returns to retrieval spool  16 , instead of transferring the label  99  from peel unit  60  to applicator unit  70 , as with an operational label  99 . It is contemplated that other orientations may exist that would require mounting portion  34  to translate in different directions to effect label ejection, including rotational translations. Ejector slide unit  32  mounts to the snorkel base  22 .  
         [0023]     Spring block unit  40  ensures proper label web  19  alignment and tension along top plate  62  and comprises a rod  42 , a block  44  with securement means  46 , and a spring plate  48 . In the present embodiment, rod  42  attaches to mounting portion  34 ; however, it is contemplated that it could mount elsewhere, such as to top plate  62 . Block  44  translates axially and radially about rod  42 , allowing spring plate  48  to track the location of label web  19  and conform to the thickness of label web  19 . Block  44  includes a securing means  46  for constraining block  44  to rod  42 . In the present embodiment, the securing means  46  comprises a levered screw, although it is contemplated that any commercially available means may be used. Spring plate  48  attaches to block  44 . By properly positioning and securing block  44 , spring plate  48  applies pressure to label web  19  so to assist in constraining label web  19  as it approaches the antenna unit  50  and the peel unit  60 . Spring plate  48  is made of acetal resin, such as DuPont&#39;s Delrin®, or any comparable commercially available material that does not interfere with RF waves. This provides more consistent read/write cycles between antenna  54  and the RFID labels  99 , since the use of bare metal interferes with those cycles. It is contemplated that insulated metal may also be used. Rod  42 , block  44 , and securing means  46  may be formed of any commercially available material, whether metal or non-metal.  
         [0024]     Antenna unit  50  transmits and receives RF waves from a RFID label  99  and comprises an antenna housing  52 , an antenna  54  (not shown), and an insulating plate  56 . In the present embodiment, antenna unit  50  attaches to mounting portion  34 ; however, it is contemplated that antenna unit  50  may mount elsewhere, such as to top plate  62 . Antenna housing  52  generally protects antenna  54  from physical damage by enclosing antenna  54  therein. In the present embodiment, antenna housing  52  is made of acetal resin. such as Delrin®, or any comparable material available commercially that does not interfere with RF signals sent to or from antenna  54 . Because proper RF transmission to and from antenna  54  generally requires, based on the present embodiment, non-metallic material to be no closer than approximately one-half inch (½″) from antenna  54 , a spacer made from acetal resin, or any other comparable material, may be required when attaching housing  52  to mounting portion  34 . The location of metallic material in relation to antenna  54  may change as stronger or weaker RF waves are transmitted from antenna  54 , thereby allowing metallic materials to be closer than or requiring metallic materials to be farther than one-half inch (½″) from antenna  54 . Insulating plate  56  secures to the label web  19  upstream side (or the block  44  side) of antenna housing  52 , to prevent approaching RFID labels  99  from being adversely affected by RF waves sent between antenna  54  and the intended RFID label  99  (generally closest to antenna  54 ). In the present embodiment, insulating plate  56  is made of stainless steel; however, it is contemplated that any other reflective material may be used. Antenna  54  comprises any commercially available RF antenna, such as those supplied by SAMSys Technologies Inc.  
         [0025]     Referring to  FIGS. 6-7 , peel unit  60 , generally, initiates the physical portion of the label application and ejection processes and comprises top plate  62 , bottom plate  64 , peel plate  66 , peel edge  67 , and return edge  69 . If read/write unit  18  determines a label  99  operational, the label  99  is separated from label web  19  at peel edge  67  and transferred to application unit  70  for product application. Tensile forces arising between the label  99  and the label web backing cause the label  99  to separate from label web  19  at peel edge  67 , due to the high return angle (the acute course or bend) experienced by label web  19  as it navigates around peel edge  67  toward retrieval spool  16 . If read/write unit  18  determines a label  99  is defective or otherwise rejected, the label  99  remains on label web  19  by retracting top plate  62 . This provides a more gradual (obtuse) path around peel edge  67 , thereby avoiding the separation forces associated with a high return angle. In the present embodiment, top plate  62  attaches to mounting portion  34  below spring plate  48  and antenna unit  50 ; however it is contemplated top plate  62  may mount elsewhere, such as to antenna unit  50 , and above spring plate  48  and antenna unit  50 . Further, top plate  62  is made of acetal resin, such as Delrin , or any comparable material available commercially that does not interfere with RF signals. In the present embodiment, top plate  62  thickness is approximately one-half inch (½″) to prevent RF signal interference resulting from signal reflections, as seen at higher thicknesses; however, it is contemplated that different thickness may be required based upon the material used and/or the existing RF system (having different RF wave frequencies and amplitudes).  
         [0026]     Peel plate  66  attaches to at least a portion of the top plate  62  and is located along a top edge and adjacent side thereof, where the downstream portion of the RFID web travels after passing antenna unit  50  (typically located nearest the label applicator unit  70 ). Any commercially available means of attachment may be used, including fasteners and clips. The purpose of peel plate  66  is to provide a replaceable wear part, since the label web  19  travels over and around the uppermost portion thereof, of which at least includes the peel edge  67 . In the present embodiment, the side portion of top plate  62  adjacent peel plate  66  is chamfered or angled (linearly or arced) inward from the uppermost portion of the top plate  62 ; although it is contemplated that peel plate  66  may comprise a triangular-like cross-section in an effort to duplicate the present profile formed by top plate  62  with peel plate  66 . The purpose of the angled side is to provide a high angle of return (an acute course or bend) for label web  19  (generally more than ninety degrees (90° )) about peel edge  67  for separating labels  99  from label web  19 . Peel plate  66  generally has a trapezoidal cross-sectional shape, thereby facilitating its mounting to top plate  62  while maintaining an uppermost surface that is substantially co-planar with the uppermost surface of top plate  62 . Peel edge  67  may include mounting flanges  68 , which extend further along the mounting side of top plate  62 . The inclusion of flanges  68  facilitates the reduction of material in the remaining portions of peel plate  66 , thereby minimizing RF signal reflection (interference). In the present embodiment, peel plate  66  is made from stainless steel for its wear properties; however, it is contemplated that peel plate  66  may be made from any other comparable metal or non-metal material. It is also contemplated that the cross-sectional shape of peel plate  66  may be non-trapezoidal and the peel plate  66  may mount to the uppermost surface of top plate  62 .  
         [0027]     Bottom plate  64  attaches to snorkel base  22  below and in close proximity to top plate  62 , for the purpose of providing support thereto. It is contemplated that bottom plate  64  may mount elsewhere, such as to the stationary portion of slide unit  32 . In the present embodiment, bottom plate  64  is made of aluminum; however, it is contemplated that different materials may be used, such as steel or acetal resin. The aluminum bottom plate  64  comprises a frame having an open center, for the purpose of minimizing RF reflection, and is approximately three-eighths of an inch (⅜″) thick; however, different designs and thicknesses may be required or allowed based upon the material used and/or the existing RF system (having different RF wave frequencies and amplitudes). A return edge  69  attaches to a side of bottom plate  64  substantially adjacent to peel edge  67 , so to contact label web  19  after translating from peel edge  67 . Return edge  69  is rounded and made of acetal resin, such as Delrin®, or any other comparable material available commercially. This minimizes damage to label web  19  by providing a low-friction surface for improved translation as web  19  exits peel edge  67 , around bottom plate  64  and toward retrieval spool  16 .  
         [0028]     Once a label  99  is separated from the label backing at the peel edge  67 , it travels to the applicator unit  70  (referring again to  FIGS. 3-5 ). In the present embodiment, applicator unit  70  utilizes a tamp blow application method; however, it is contemplated that merge or air-blow application methods may be used. The tamp applicator unit  70  includes tamp slide mechanism  72 , actuator (or cylinder)  74 , manifold  76 , and label pad  78 . Tamp slide mechanism  72  provides a unit that translates in response to actuator  74 , and to which manifold  76  mounts. Manifold  76  provides a vacuum that allows attached label pad  78  to grasp a label  99  as it separates from the label web backing at peel edge  67 . While label pad  78  grasps the label  99 , actuator  74  directs label pad  78  via tamp slide mechanism  72  toward the to-be-labeled product. Applicator unit  70  then applies the label  99  retained by label pad  78  by terminating the vacuum and then blowing the label  99  against the product. In the present embodiment, a product sensor initiates actuator  74  and/or the termination of the vacuum and creation of the blow operation. In use, the product sensor may initiate actuator  74 , terminate vacuum, and blow sequentially as stated above. Also, actuator  74  may extend to a predefined length without receiving any signal from the product sensor, which then only requires product sensor to initiate termination of the vacuum and generation of the blow operation. It is contemplated that any commercially available applicator unit  70  may be used, except that label pad  78  is to be made of aluminum, or any other comparable metal or metal composite that prevents RF waves from adversely affecting the label  99  grasped by label pad  78 . It is further contemplated that applicator unit  70  may include either actuator  74  or the blow operation, without the other.  
         [0029]      FIGS. 8-11  show the operation of label applicator  10 , and more specifically the progression of label web  19  and RFID labels  99  through the snorkel unit  20 . In operation, and after entering snorkel unit  20 , label web  19  translates upon the top plate  62  of peel unit  60  to place a label  99   a  below antenna unit  50  ( FIG. 8 ). At this time, any read/write operations are performed on label  99   a.  After all read/write operations are complete, label web  19  continues to translate upon top plate  62  toward peel edge  67 . As a label  99  approaches peel edge  67 , the read/write unit  18  has already determined whether label  99   a  is to be applied to a product or whether label  99   a  is to be ejected. If label  99   a  is to be ejected ( FIG. 9 ), top plate  62  slides away from the applicator unit  70  (in the label web  19  upstream direction), thereby allowing label web  19  to continue to travel toward applicator unit  70  at a decreasing angle (in an obtuse course or bend) until reaching return edge  69 , whereupon the label web  19  travels around toward retreival spool  16 . This course of travel reduces separation stresses (primarily tensile) within the adhesive between label  99   a  and label web  19 , thereby allowing label  99   a  to remain on label web  19  as it returns to retrieval spool  16 . As the ejected label is removed from top plate  62 , another label  99   b  is being placed underneath antenna unit  50  to begin the same process. If label  99   a  is operational ( FIGS. 10-11 ), label web  19  proceeds over and about peel edge  67 , leaving peel edge  67  in a downward direction (in an acute course or bend) away from applicator unit  70 . This provides separation stresses (primarily tensile) within the adhesive between label  99   a  and label web  19 , sufficient to separate label  99   a  from label web  19 . Applicator unit  70  then obtains label  99   a  for its application to a product. As label  99   a  is being transferred to applicator unit  70 , label  99   b  is being placed into position under antenna unit  50  to begin the same process. While applicator unit  70  is applying label  99   a  to a product, read/write operations may begin to reduce any delay in translating label  99   b  after application of label  99   a.  Note, the read/write operations upon a label  99  may begin before a label  99  is completely under antenna unit  50  (or as label  99  translates towards antenna unit  50 ) and may continue as label  99  translates away from antenna unit  50 .  
         [0030]     Although the present invention has been described above in detail, the same is by way of illustration and example only and is not to be taken as a limitation on the present invention.