Patent Abstract:
An apparatus for grouping electronic price labels (EPLs) which facilitates installation of electronic price labels in signs and promotional displays rather than standard shelf edges. The apparatus primarily includes a frame member for mounting the EPLs including a plurality of bays arranged in a plurality of rows and columns. The apparatus additionally includes a product description sheet mounted to the frame member including apertures for exposing displays within the EPLs. Optionally included are a product description sheet holder which mounts to the frame member for retaining the product description sheet against the front surface and a base for supporting the frame member on a flat surface.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 08/961,514 filed on Oct. 30, 1997. 
     The present invention is related to the following commonly assigned U.S. applications and U.S. patents: 
     U.S. Pat. No. 6,098,049, entitled “Electronic Price Label System Including Groups Of Electronic Price Labels And Method Of Managing The Groups”, filed Oct. 30, 1997, and invented by Goodwin et al.; 
     U.S. Pat. No. 5,987,427, entitled “Electronic Price Label System Including Groups Of Electronic Price Labels And Method Of Managing The Groups”, filed Oct. 30, 1997, and invented by Goodwin et al.; and 
     Ser. No. 08/960,801, entitled, “Apparatus For Grouping Electronic Price Labels”, filed Oct. 30, 1997, and invented by Forsythe et al. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to electronic price label (EPL) systems used in transaction establishments, and more specifically to an apparatus for grouping electronic price labels. 
     EPL systems typically include a plurality of EPLs for each merchandise item in a store. EPLs typically display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of EPLs to display the prices of the merchandise items. The EPLs are coupled to a central server from where information about the EPLs is typically maintained in an EPL data file. Price information displayed by the EPLs is obtained from the PLU file. 
     EPLs today may be wired or wireless. Wireless EPLs may employ infrared or radio frequency transmitters to transmit acknowledgment signals acknowledging receipt of messages and to relay acknowledgment signals from other EPLs to receiving devices coupled to a main EPL computer. 
     Current shelf mounting arrangements for EPLs work well in a typical store environment. However, they are not well-suited for displaying price information on a family of products or a plurality of styles associated with a single product. They are also not well-suited for promoting items located on end-aisles, walls, and other promotional structures besides standard store shelving. Mass merchants, including department store retailers desire more flexibility in mounting EPLs to better promote their products. 
     Therefore, it would be desirable to group EPLs in containers, such as cassettes. It would also be desirable to provide a method of managing the groups. 
     SUMMARY OF THE INVENTION 
     In accordance with the teachings of the present invention, apparatus for grouping electronic price labels is provided. 
     The apparatus primarily includes a frame member for mounting the EPLs including a plurality of bays arranged in a plurality of rows and columns. The apparatus additionally includes a product description sheet mounted to the frame member including apertures for exposing displays within the EPLs. Optionally included are a product description sheet holder which mounts to the frame member for retaining the product description sheet against the front surface and a base for supporting the frame member on a flat surface. 
     A method of grouping EPLs includes the steps of inserting the EPLs into rows and columns of bays arranged within a frame member, placing a product description sheet adjacent to the frame member, and orienting apertures in the product description sheet adjacent displays within the EPLs so as to expose the displays. 
     It is a feature of the present invention that a plurality of prices can be displayed for a plurality of related items. Thus, the groups are particularly suited for use in promotional signs. 
     It is also a feature of the present invention that the apparatus can be mounted vertically, such as on walls, and placed on horizontal surfaces, such as tables. Thus, the present invention provides an alternative to mounting EPLs on shelf edges. 
     It is accordingly an object of the present invention to provide an apparatus for grouping electronic price labels (EPLs). 
     It is another object of the present invention to provide an apparatus for grouping EPLs into rows and columns. 
     It is another object of the present invention to provide an apparatus for facilitating use of EPLs in promoting items that are not located on standard merchandise shelves. 
     It is another object of the present invention to provide a sign or other promotional apparatus containing groups of EPLs arranged in rows and columns. 
     It is another object of the present invention to provide a sign or other promotional apparatus containing groups of EPLs for displaying different prices associated with related items. 
     It is another object of the present invention to provide an electronic price label system including groups of EPLs and method of managing the groups. 
     It is another object of the present invention to provide a system and method of managing rows and columns of EPLs which display different prices for different items. 
     It is another object of the present invention to provide a system and method of managing rows and columns of EPLs which display different prices for different styles of a number of items. 
     It is another object of the present invention to provide a system and method of managing rows and columns of EPLs which display regular and special prices for different items. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a block diagram of a transaction management system, including an EPL system; 
     FIG. 2 is a diagram of a PLU data file; 
     FIGS. 3A and 3B are diagrams of EPL data files; 
     FIG. 4 is a diagram of an EPL group definition file; 
     FIG. 5 is a diagram of an EPL assignment file; 
     FIG. 6 is a flow diagram illustrating operation of group definition software; 
     FIG. 7 is a flow diagram illustrating operation of EPL assignment software; 
     FIGS. 8A and 8B form a flow diagram illustrating operation of a first embodiment of PLU assignment software; 
     FIG. 9 is a flow diagram illustrating operation of a second embodiment of PLU assignment software; 
     FIGS. 10A and 10B form an exploded view of a first sign incorporating a cassette; and 
     FIG. 11 is a second sign incorporating a cassette. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, a transaction management system  10  primarily includes host computer system  12 , point-of-service (POS) system  14 , and EPL system  16 . 
     Host computer system  12  includes storage medium  36 , host PLU terminal  40 , and input device  42 . 
     Storage medium  36  stores PLU data file  44 . PLU data file  44  stores item prices and is available for distribution to POS terminal  20  by host PLU terminal  40 . Alternatively, provision may be made for bar code scanner  18  to directly access primary PLU file  44  from host PLU terminal  40 . 
     Here, terminals  20 ,  24 , and  40  are shown as separate components that are networked together, but they may also be combined in different ways. For example, EPL terminal  24  and host PLU terminal  40  may be combined to form a single host computer. POS terminal  20  and host PLU terminal  40  may be combined to form a POS terminal which doubles as a host computer for a network of other POS terminals. 
     Host PLU terminal  40  executes PLU maintenance routine  50 . PLU maintenance routine  50  updates PLU data file  44 . 
     Input device  42  is preferably a keyboard. 
     PLU maintenance routine  50  may send changes in price in PLU file  44  directly to EPL terminal  24  and POS terminal  20  as they are entered in input device  42  (immediate processing) or store price changes within a batch file  51  in storage medium  36  for later batch updating (batch processing). 
     PLU data file  44  (FIG. 2) includes a line entry for each item sold in the store. Each line entry has an item identification entry (ITEM ID), and PLU price entries (PRICE  1 , PRICE  2 , etc.). Entry ITEM ID identifies a store item. Entry PRICE  1  typically identifies the regular price read by POS system  14  to determine the price of an item during scanning by bar code scanner  18 . When present, the additional prices (PRICE  2 , PRICE  3 , etc.) may include special or “sale” prices or additional version/style prices associated with an item. 
     POS system  14  includes bar code scanner  18  and terminal  20 . 
     EPL system  16  primarily includes EPLs  22 , host EPL terminal  24 , and EPL storage medium  26 . 
     EPLs  22  include EPLs  22 A and EPLs  22 B. EPLs  22 B are typically attached to shelves within a store. Grouped EPLs  22 A are assigned to a product having different versions or styles. Thus, each EPL  22 A displays prices of different versions or special prices associated with a single product&#39;s ITEM ID. EPLs  22 A may be arranged in a cassette  220  (FIG. 10B) or other suitable holder. 
     Host EPL terminal  24  executes EPL software  30  and group management software  34 . Host EPL terminal  24  obtains price information from PLU data file  44  and sends it to EPLs  22 . EPL software  30  schedules price change messages for transmission to EPLs  22  and manages communication between host EPL terminal  24  and EPLs  22 . 
     EPL software additionally maintains EPL data file  32  (FIGS.  3 A and  3 B). EPL data file  32  includes a line entry for each EPL  22  in EPL system  16 . Each line entry has an item identification entry (ITEM ID), an EPL identification entry (EPL ID), and may additionally include an EPL price checksum value entry (EPL CHECK). 
     Entry ITEM ID identifies a store item. Entry EPL ID identifies which EPL is assigned to the item. Entry EPL CHECK is a checksum value of the digits of the price information that is displayed by EPL  22 . 
     In a first embodiment (FIG.  3 A), a normally unused bit within an identification number for an item is used to identify a price for the item when a plurality of prices (PRICE  1 , PRICE  2 , etc.) are listed for the item in PLU data file  44 . Alternatively, an additional bit may be added to the item identification numbers to identify which prices to display. 
     In a second embodiment (FIG.  3 B), an additional entry for a price identifier (PRICE) is added to EPL data file  32  to identify a price for the item when a plurality of prices are listed for the item in PLU data file  44 . The price identifier equals “1” for PRICE  1 , “2” for PRICE  2 , etc. 
     Group management software  34  manages assignment of EPLs  22 A to groups and item identification numbers to EPLs  22 A. For this purpose, group management software  34  includes EPL assignment software  35 , group definition software  37 , and PLU assignment software  38 . 
     Group definition software  37  stores group definition information in group definition file  46  (FIG.  4 ). Group definition file  46  includes line entries for group numbers (GROUP#), a total number of EPLs  22 A in the group (EPLs), and the number of EPLs  22 A per line (EPLs/LINE). For example, a two-by-five grouping of EPLs  22 A would have two columns and five rows of EPLs  22 A. The total number of EPLs  22 A in the group would be ten. The number of EPLs  22 A per line would two. 
     EPL assignment software  35  stores EPL assignment information in EPL assignment file  52  (FIG.  5 ). EPL assignment file  52  includes line entries for group numbers (GROUP#), relative number of each EPL  22 A within the group (EPL#), and EPL identification numbers (EPL ID). In the preceding example, relative numbers are determined from left to right and top to bottom. Thus, the two EPLs  22 A in the first row would have relative EPL numbers of “1” and “2”. 
     PLU assignment software  38  assigns item identification numbers to EPLs  22 A within groups. Item assignments are stored within EPL data file  32 , along with item assignments of EPLs  22 B. 
     EPL storage medium  26  stores EPL data file  32 , group definition file  46 , and EPL assignment file  52 , and is preferably a fixed disk drive. 
     EPL system  16  additionally includes input device  47  and display  48 . Input device  47  records information to be stored within EPL data file  32 , group definition file  46 , and EPL assignment file  52 . Input device  47  is preferably a keyboard. 
     Display  48  displays program and recorded information during execution of EPL assignment software  35 , group definition software  37 , and PLU assignment software  38 . 
     Turning now to FIGS. 6-8, the operation of group management software  34  is illustrated in more detail. 
     With reference to FIG. 6, operation of group definition software  37  begins with START  60 . 
     In step  62 , group definition software  37  displays a prompt for an operator to select to create, delete, or modify a group using display  48 . 
     In step  64 , group definition software  37  records the operator choice entered using input device  47 . 
     In step  66 , group definition software  37  determines from the recorded choice whether a group is to created, deleted, or modified. 
     For deletion, operation proceeds to step  67 . 
     In step  67 , group definition software  37  displays a prompt for a group number using display  48 . 
     In step  68 , group definition software  37  records a group number (GROUP #) entered by the operator using input device  47 . 
     In step  70 , group definition software  37  deletes group definition information for the selected group from group definition file  46 . 
     Operation proceeds to step  82 . 
     Returning now to step  66 , for creation, operation proceeds to step  71 . 
     In step  71 , group definition software  37  displays a prompt for the operator to enter group definition information. 
     In step  72 , group definition software  37  records a group number (GROUP #), total number of EPLs in the group (EPLs), and number of EPLs per line (EPLs/LINE) for the group entered by an operator. 
     In step  74 , group definition software  37  stores the group definition information in group definition file  46 . 
     Operation proceeds to step  82 . 
     Returning now to step  66 , for modification, operation proceeds to step  75 . 
     In step  75 , group definition software  37  displays a prompt for a group number (GROUP #). 
     In step  76 , group definition software  37  records a group number entered by an operator. 
     In step  77 , group definition software  37  displays a prompt for group definition information. 
     In step  78 , group definition software  37  records group definition information, including total number of EPLs in the group (EPLs), and number of EPLs per line (EPLs/LINE) for the group entered by an operator. 
     In step  80 , group definition software  37  stores the group definition information in group definition file  46 . 
     Operation proceeds to step  82 . 
     In step  82 , group definition software  37  displays a prompt for program return to create, delete, or modify another group, or for program end. 
     In step  84 , group definition software  37  records the operator choice entered using input device  47 . 
     In step  86 , group definition software  37  determines from the recorded choice whether to create, delete, or modify another group or end. 
     For return, operation returns to step  62 . 
     For end, operation ends in step  88 . 
     With reference to FIG. 7, operation of EPL assignment software  35  begins with START  90 . 
     In step  92 , EPL assignment software  35  displays a prompt for a group number (GROUP #) using display  48 . 
     In step  94 , EPL assignment software  35  records a group number entered by an operator using input device  47 . 
     In step  96 , EPL assignment software  35  determines the number of EPLs (EPLs) in the selected group from group definition file  46 . 
     In step  98 , EPL assignment software  35  displays the a list of relative numbers (EPL #) of all EPLs  22 A in the selected group. 
     In step  100 , EPL assignment software  35  displays a prompt for a relative EPL number from the list. 
     In step  102 , EPL assignment software  35  records a relative EPL number entered by the operator. 
     In step  104 , EPL assignment software  35  displays a prompt for an EPL identification number (EPL ID) to be assigned to an EPL  22 A. 
     In step  105 , EPL assignment software  35  records an EPL identification number entered by the operator. 
     In step  106 , EPL assignment software  35  stores the EPL identification number for the EPL in EPL assignment file  52 . 
     In step  108 , EPL assignment software  35  displays a prompt for program return to assign an EPL identification number to the next EPL in the relative number list, or for operation to continue. 
     In step  110 , EPL assignment software  35  records the operator choice entered using input device  47 . 
     In step  112 , EPL assignment software  35  determines from the recorded choice whether to return or continue. 
     For return, operation returns to step  98  to assign an EPL identification number to the next EPL in the relative number list. Operation returns to step  100  until the last EPL in the relative number list has been assigned an EPL identification number. 
     Otherwise, operation continues in step  114 . 
     In step  114 , EPL assignment software  35  displays a prompt for program return to select another group, or for program end. 
     In step  116 , EPL assignment software  35  records the operator choice entered using input device  47 . 
     In step  118 , EPL assignment software  35  determines from the recorded choice whether to return to select another group, or to end. 
     For return, operation returns to step  92  to select another group. 
     Otherwise, operation ends at END  120 . 
     With reference to FIGS. 8A and 8B, operation of a first embodiment of PLU assignment software  38  begins with START  130 . In this embodiment, prices for different versions of the same item are identified by a special bit in the item identification number. Thus, each EPL  22 A receives a unique item identification number. EPL data file  32  of FIG. 3A is employed. 
     In step  132 , PLU assignment software  38  displays a prompt for a group number using display  48 . 
     In step  134 , PLU assignment software  38  records a group number entered by an operator using input device  47 . 
     In step  136 , PLU assignment software  38  determines the number of EPLs (EPLs) in the selected group from group definition file  46 . 
     In step  138 , PLU assignment software  38  displays a list of the determined EPLs and their relative number assignments (EPL #). 
     In step  140 , PLU assignment software  38  displays a prompt for a relative EPL number (EPL #) within the selected group. 
     In step  142 , PLU assignment software  38  records the relative EPL number entered by the operator. 
     In step  144 , PLU assignment software  38  reads a corresponding EPL identification number (EPL ID) for the selected relative EPL number from EPL assignment file  52 . 
     In step  146 , PLU assignment software  38  displays a prompt for an item identification number (ITEM ID) to be assigned to the selected relative EPL number. 
     In step  148 , PLU assignment software  38  records an item identification number entered by the operator. 
     In step  149 , PLU assignment software  38  displays a list of modified item identification numbers and their prices. The modified item identification numbers include the item identification number and special bits to identify prices within PLU data file  44  for the same item. 
     In step  150 , PLU assignment software  38  displays a prompt for a modified item identification number to be assigned to the selected relative EPL number. 
     In step  151 , PLU assignment software  38  records a modified item identification number entered by the operator. 
     In step  152 , PLU assignment software  38  stores the modified item identification number for the relative EPL number in EPL data file  32  in the record of the EPL identification number. 
     In step  154 , PLU assignment software  38  displays a prompt for program return to assign another item to another relative EPL number, or for operation to continue. 
     In step  155 , PLU assignment software  38  records the operator choice entered using input device  47 . 
     In step  156 , PLU assignment software  38  determines from the recorded choice whether to return or continue. 
     For return, operation returns to step  138  to assign another item identification number to another relative EPL number in the selected group. 
     Otherwise, operation continues in step  158 . 
     In step  158 , PLU assignment software  38  displays a prompt for program return to select another group, or for program end. 
     In step  160 , PLU assignment software  38  records the operator choice entered using input device  47 . 
     In step  162 , PLU assignment software  38  determines from the recorded choice whether to return to select another group, or to end. 
     For return, operation returns to step  132  to select another group. 
     Otherwise, operation ends at END  164 . 
     Advantageously, PLU assignment software  38  assigns merchandise items to relative EPL numbers by automatically determining the EPL identification numbers. The operator does not need to know any EPL identification numbers in order to assign items to relative EPL numbers within groups. 
     With reference to FIG. 9, operation of a second embodiment of PLU assignment software  38  begins with START  170 . In this embodiment, prices for different versions of the same item are identified by a relative price entry PRICE in EPL data file  32 . Thus, each EPL  22 A within a group receives the same item identification number. Prices are differentiated using the relative price entry PRICE. EPL data file  32  of FIG. 3B is employed. 
     In step  172 , PLU assignment software  38  displays a prompt for a group number using display  48 . 
     In step  174 , PLU assignment software  38  records a group number entered by an operator using input device  47 . 
     In step  176 , PLU assignment software  38  determines the number of EPLs (EPLs) in the selected group from group definition file  46 . 
     In step  178 , PLU assignment software  38  displays a list of the determined EPLs and their relative number assignments (EPL #). 
     In step  180 , PLU assignment software  38  displays a prompt for a relative EPL number (EPL #) within the selected group. 
     In step  182 , PLU assignment software  38  records the relative EPL number entered by the operator. 
     In step  184 , PLU assignment software  38  reads a corresponding EPL identification number (EPL ID) for the selected relative EPL number from EPL assignment file  52 . 
     In step  186 , PLU assignment software  38  displays a prompt for an item identification number (ITEM ID) to be assigned to the selected relative EPL number. 
     In step  188 , PLU assignment software  38  records an item identification number entered by the operator. 
     In step  190 , PLU assignment software  38  stores the item identification number for the relative EPL number in EPL data file  32  in the record of the EPL identification number. 
     In step  192 , PLU assignment software  38  displays a list of prices for the item in PLU data file  44 . 
     In step  194 , PLU assignment software  38  displays a prompt for a relative price number (PRICE) to be assigned to the selected relative EPL number. 
     In step  196 , PLU assignment software  38  records a relative price number entered by the operator. 
     In step  198 , PLU assignment software  38  stores the relative price number for the relative EPL number in EPL data file  32  in the record of the EPL identification number. 
     In step  200 , PLU assignment software  38  displays a prompt for program return to assign another item to another relative EPL number, or for operation to continue. 
     In step  202 , PLU assignment software  38  records the operator choice entered using input device  47 . 
     In step  204 , PLU assignment software  38  determines from the recorded choice whether to return or continue. 
     For return, operation returns to step  178  to assign another item identification number to another relative EPL number in the selected group. 
     Otherwise, operation continues in step  206 . 
     In step  206 , PLU assignment software  38  displays a prompt for program return to select another group, or for program end. 
     In step  208 , PLU assignment software  38  records the operator choice entered using input device  47 . 
     In step  210 , PLU assignment software  38  determines from the recorded choice whether to return to select another group, or to end. 
     For return, operation returns to step  172  to select another group. 
     Otherwise, operation ends at END  212 . 
     Advantageously, PLU assignment software  38  assigns merchandise items to relative EPL numbers by automatically determining the EPL identification numbers. The operator does not need to know any EPL identification numbers in order to assign items to relative EPL numbers within groups. 
     Turning now to FIGS. 10A and 10B, sign  220  includes EPL cassette  222 , product description sheet holder  223 , and product description sheet  224 . 
     Cassette  222  includes rows and columns of bays  226  for installing EPLs  22 A. Here, two columns and five rows of bays  226  are shown. However, the present invention envisions other numbers of rows and columns as well. Not all bays  226  need be filled with EPLs  22 A. The number of EPLs  22 A is determined by the product or products associated with sign  220  and the product description sheet  224 . Cassette  222  is preferably made of plastic. 
     In more detail, each bay  226  includes left wall  228 , right wall  230 , top wall  232 , bottom wall  234 , and back wall  236 . Walls  228 - 234  are planar and form a frame for openings having substantially similar dimensions as the perimeters of EPLs  22 A. 
     EPLs  22 A include feet  238  and locking tabs  240  for retaining EPLs  22 A within bays  226 . EPLs  22 A are inserted within bays  226  by inserting the bottom edge and feet  238  first, and the inserting the top edge and locking tabs  240  last. Removal is accomplished in reverse after using a key to depress locking tabs  240 . 
     Bottom walls  234  include bottom support members  242  upon which EPLs  22 A sit. Bottom support members  242  include end portions  244  which retain feet  238  in place within bays  226 . 
     Back walls  236  include a include feet viewing apertures  246  and tab viewing apertures  248 . Feet viewing apertures  246  allow an operator to access feet  238  and end portions  244 . Tab viewing apertures  248  are located near the upper edges of back walls  236  and allow an operator to access locking tabs  240 . 
     Each bay  226  is deep enough so that the front surfaces  254  of EPLs  22 A are substantially flush with front surface  256  of cassette  222 . 
     Cassette  222  may additionally include base  252  for supporting cassette  222  on a table or other flat surface. Here, base  252  is attached to cassette  222 , however, base  252  may also be integrally manufactured with cassette  222 . The disclosed cassette  222  with base  252  allows product description sheet  226  to be inclined, but other cassette orientations, including substantially vertical orientations, are also envisioned. Cassette  222  may also be manufactured without base  252  so that cassette  222  may be mounted on walls and other substantially vertical surfaces. 
     Cassette  222  additionally includes top and bottom retaining members  258  and  260  which retain product description sheet holder  223  against front surface  256  of cassette  222  and front surfaces  254  of EPLs  22 A. Product description sheet holder  223  is inserted into cassette  222  by first placing bottom edge  262  behind bottom retaining member  260  and then pressing top edge  264  under top retaining member  258 . Once in place, product description sheet holder  223  is held snugly in place by bottom retaining member  260  and top retaining member  258 , but can be easily removed by applying a removal force to top edge  264  and top retaining member  258 . Thus, reconfiguration with a different product description sheet  224  is easily accomplished. 
     Product description sheet holder  223  retains product description sheet  224 . For this purpose, product description sheet holder  223  is generally U-shaped, having first and second panels  270  and  272 . Panels  270  and  272  join at top edge  264 . Product description sheet holder  223  is preferably made of transparent Plexiglas or plastic. 
     Product description sheet  224  slides between panels  270  and  272  of product description sheet holder  223 . Product description sheet  224  includes item identification information, such as product name, brand, and style, and may additionally include other promotional information. Product description sheet  224  includes apertures  274  which line up with displays  280  of EPLs  22 A when sign  220  is assembled with installed EPLs  22 A. 
     Advantageously, sign  220  is particularly suited for promoting items that are not located on standard store shelving, such as end-aisle structures. Sign  220  may be mounted on a wall or placed on a table. 
     FIG. 10A illustrates a product description sheet  224  which includes promotional information for a special or “sale” promotion for different items. For each line, one of EPLs  22 A displays a regular price and the other EPL  22 A displays a sale price. 
     FIG. 11 illustrates a product description sheet  224  which includes promotional information for different styles or types of a single product. Each style has a corresponding EPL  22 A for displaying the regular price of the style and the sale price of the style. 
     Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.

Technology Classification (CPC): 6