1
                                                                   EXHIBIT 3.9

                              ARTICLES OF AMENDMENT
                       TO THE ARTICLES OF INCORPORATION OF
                              EAE INDUSTRIES, INC.


     Pursuant to the provisions of Article 4.04 of the Texas Business
Corporation Act, EAE Industries, Inc. (hereinafter referred to as the
"Corporation") adopts the following Articles of Amendment to its Articles of
Incorporation: 

     (1) NAME. The name of the Corporation is EAE Industries, Inc.

     (2) AMENDMENT IS ALTERATION. This Articles of Amendment to the Articles of
Incorporation alters Article IV of the Articles of Incorporation of the
Corporation. The full text of Article IV as it is amended to read by this
Articles of Amendment is quoted below: 

                                  "ARTICLE IV

                      AUTHORIZED STOCK AND SHARE STRUCTURE

          A. Authorized Common Shares. The Corporation is authorized to issue
     twenty thousand (20,000) shares of common stock, in the aggregate, at no
     par value. No distinction shall exist between the shares of the Corporation
     or between the holders of the shares. The shares of common stock shall have
     identical rights and privileges in every respect.

          B. Authorized Preferred Shares. The Corporation is authorized to issue
     five hundred thousand (500,000) shares of preferred stock, in the
     aggregate, with a par value of One and No/100 Dollars ($1.00). The
     preferred shares of the Corporation shall be non-voting and shall be
     preferred upon liquidation in the amount of One and No/100 Dollars ($1.00)
     for each outstanding share. A noncumulative dividend of seventy cents
     ($.70) per share shall be payable with respect to such preferred shares out
     of the funds legally available."

     (3) ADOPTION. The above Amendment to the Articles of Incorporation was
adopted by the unanimous written consent of all of the shareholders of the
Corporation on the 16 day of July, 1997.

     (4) SHARES. The number of shares of stock of the Corporation outstanding at
the time

   2

of the adoption of this Amendment to the Articles of Incorporation was 10,000. 
The number of shares entitled to vote thereon as a class was 10,000, all of 
which were shares of voting common stock.

     (5) VOTES. All of the shareholders of the Corporation voted in favor of
this Articles of Amendment to the Articles of Incorporation by signing a consent
in writing adopting such amendment. 

     (6) ISSUED SHARES. This Articles of Amendment does not provide for an
exchange, reclassification or cancellation of issued shares. 

     (7) STATED CAPITAL. This Articles of Amendment does not effect a change in
the amount of stated capital. Pursuant to Article 4.05 of the Texas Business
Corporation Act, this original Articles of Amendment and a copy thereof shall be
delivered for filing to the Secretary of State of the State of Texas. 

DATED: August 5, 1997. 

                                        EAE INDUSTRIES, INC.

                                        BY: /s/DAVID B. AMMONS
                                           ------------------------------------
                                             David B. Ammons, Secretary