Notice of Maintenance Fees Payable

   Title 37 Code of Federal Regulations (CFR), Section 1.362(d) provides that
maintenance fees may be paid without surcharge for a six-month period beginning
3, 7, and 11 years after the date of issue of patents based on applications
filed on or after Dec. 12, 1980. An additional six-month grace period is
provided by 35 U.S.C. 41(b) and 37 CFR 1.362(e) for payment of the maintenance
fee with the surcharge set forth in 37 CFR 1.20(h), as amended effective Dec.
16, 1991. If the maintenance fee is not paid in the patent requiring such
payment the patent will expire on the 4th, 8th, or 12th anniversary of the
grant.

   Attention is drawn to the patents which were issued on May 19, 1992 for
which maintenance fees due at 3 years and six months may now be paid. The
patents have patent numbers within the following ranges:

        Utility Patents 5,113,526 through 5,115,515
        Reissue Patents based on the above identified patents.

   Attention is drawn to the patents which were issued on May 17, 1988
for  which  maintenance fees due at 7 years and six months may now be paid.
The patents have patent numbers within the following ranges:

        Utility Patents 4,744,106 through 4,745,633
        Reissue Patents based on the above identified patents.

   Attention is drawn to the patents which were issued on May 15, 1984
for which maintenance fees due at 11 years and six months may now be paid. The
patents have patent numbers within the following ranges:

        Utility Patents 4,447,911 through 4,449,250
        Reissue Patents based on the above identified patents.

   No maintenance fees are required for design or plant patents.

   Payments of maintenance fees in patents should be directed to "Commissioner
of Patents and Trademarks, Box M. Fee, Washington, D.C. 20231."
   For patents based on applications filed on or after December 12, 1980, but
before August 27, 1982, patent owners must establish small entity status
according to 37 CFR 1.27 if they have not done so and if they wish to pay the
small entity amount.
   The current amounts of the maintenance fees due at 3 years and six months,
and 7 years and six months, and 11 years and six months are set forth in 37
CFR 1.20(e)-(g), as amended Oct. 1, 1994, which are reproduced below:

37 CFR 1.20 Post-issuance fees

(e) For maintaining an original or reissue patent, except a design or plant
    patent, based on an application filed on or after after Dec. 12, 1980, in
    force beyond 4 years; the fee is due by three years and six months after
    the original grant:

   By a small entity (1.9(f))                                          $480.00
   By other than a small entity                                        $960.00

(f) For maintaining an original or reissue patent, except a design or plant
    patent, based on an application filed on or after Dec. 12, 1980 in force
    beyond 8 years; the fee is due by seven years and six months after the
    original grant:

   By a small entity (1.9(f))                                          $965.00
   By other than a small entity                                      $1,930.00

(g) For maintaining an original or reissue patent, except a design or plant
    patent, based on an application filed on or after Dec. 12, 1980 in force
    beyond 12 years; the fee is due by eleven years and six months after the
    original grant:

   By a small entity (1.9(f))                                        $1,450.00
   By other than a small entity                                      $2,900.00

   The amount of the surcharges for paying the maintenance fee during the
grace period or after the expiration of the patent are set forth in 37 CFR
1.20(h), and (i) which are reproduced below:

(h) Surcharge for paying a maintenance fee during the 6 month grace period
    following the expiration of three years and six months, seven years and six
    months, and eleven years and six months after the date of the original grant
    of a patent based on an application filed on or after Dec. 12, 1980:

   By a small entity (1.9(f))                                           $65.00
   By other than a small entity                                        $130.00

(i) Surcharge for accepting a maintenance fee after expiration of a patent
    for non-timely payment of a maintenance fee where the delay is shown to the
    satisfaction of the Commissioner to have been:

   (1) unavoidable                                                     $640.00
   (2) unintentional                                                 $1,500.00