THE W-SIMILAR CORE FROM PLATES
                   (SHELL-TYPE)

                __________________________________
              /__________________________________/|
            /__________________________________/ ||
 ______   /__________________________________/ | |/
  /|\    |                                   | |/||
   |     |___________________________________|/| ||
   |     | /|\| | | | |         | | | | |    | | ||
   |     |  | | | | | |         | | | | |    | | ||
   |     |  | | | | | |         | | | | |    | | ||
   H     |  h | | | |_|<---y--->| | | |_|    | | ||
   |     |  | | | |/__|         | | |/__|    | | ||
   |     | \|/| |/____|         | |/____|    | | ||
   |     | ___|/______|         |/______|    | | |/
  \|/    |                      |<--b-->|    | |/
 ______  |___________________________________|/   |
                                                 /|
         |                                   | y1
         |<---------------L----------------->|/



         THE L-SIMILAR CORE FROM PLATES
                      (ROD)

         _______________________________
       /_________________________/_____/|
     /_________________________/_____/ ||
   /_________________________/_____/ | /|
  |                         |     |  / ||
  | ___ ____________________|     |/ | ||
  | /|\ |  | ||             |     |  | ||
  |  |  |  | ||             |     |  | ||
  |  |  |  | ||             |     |  | ||
  |  h  |  | ||             |<-y->|  | ||
  |  |  |  | ||_____________|     |  | ||
  |  |  |  | /______________|     |  | ||
  | \|/ |  /________________|     |  | ||
  |_____|/__________________|     |  | /
  |     |<--------b-------->|     |  /  |
  |_______________________________|/   /|
                                     y1
                                  | /
                                  |


                 THE SHELL-TYPE TAPE CORE

                      ---------------       --------------
                   .               .  \ / .             .   \
                .                .     .              .    . |
 ----------  . ---------------.     .---------------.    .   |
 /|\        / .---------------. \ /                   \.     |
  |   ---- | |  -------------  | |    -------------    |     |
  |   /|\  | | |      |      | | |   |      |      |   |     |
  |    |   | | |     .|      | | |   |     .|      |   |    .|
  |    |   | | |   .  |      | | |   |   .  |      |   |  .  |
  |    |   | | | .    |      | | |   | .    |      |   |.    |
  H    h   |-|-|      |      |-|-|- -|      |      |- -|    /|
  |    |   | | |      |      | | |   |      |      |   |  y1 |
  |    |   | | |     . ------| | |   |     . ------|   |/    |
  |    |   | | |   .         | | |   |   .         |   |    /
  |   \|/  | | | .           | | |   | .           |   |  .
  |   ---- | |  -------------  | |    ------------     |.
 \|/        \ '----------------'/ \                  /
 ----------    ---------------       --------------
               |             |       |
               |<-----b----->|<--y-->|


                       THE RING CORE
                        (TOROIDAL)
                                                           
                 *     *                      --------
            *               *                |        |
                   * *                       |_ _ _ _ | 
       *       *         *       *           |        |
                                             |        | 
    *      *                 *       *       |        |
                                             |        |
  *     *                       *      *     |        |
 |       <----------d---------->        |    |        |
 |*     *                       *      *|    |        |
 |                                      |    |        |
 | *      *                  *        * |    |        |
 |                                      |    |        |
 |     *       *         *        *     |    |        |
 |                 * *                  |    |- - - - |
 |          *               *           |    |        |
 |               *     *                |    |________|
 |                                      |             
 |<------------------D----------------->|    |        |
                                             |<--b--->|