EXHIBIT 3.13

               ARTICLES OF INCORPORATION OF GOVERNAIR CORPORATION

KNOW ALL MEN BY THESE PRESENTS:

      That the undersigned citizens of the State of Oklahoma do hereby
voluntarily associate ourselves together for the purpose of forming a private
corporation under the laws of the State of Oklahoma, and do hereby certify:

                                       I.

      The name of this corporation shall be the Governair Corporation.

                                      II.

      The term for which this corporation is to exist is twenty (20) years.

                                      III.

      The purpose for which this corporation is formed is: Manufacturing, with
the right to do all things incidental and necessary for said purpose, and
specifically for the purpose of manufacturing air conditioning units,
refrigeration units, heating units, equipment, machinery and appliances of all
kind and character, radio, and all kinds and character of electrical appliances
and equipment, and to buy and sell merchandise necessary to its business; and to
install such merchandise, units, appliances and equipment, and to advertise by
any lawful means or methods such merchandise so as to make the same readily
salable and to generally conduct a sales agency for any and all merchandise, and
especially air conditioning, refrigeration units, heating units, air cooling
and/or air purifying units, or electrical equipment and appliances designed for
such purposes, including the right to purchase or lease the necessary real
property for the carrying on of such business and to do all things whatsoever
that the general purpose herein referred to might reasonably require to
successfully and legitimately carry out such purposes under the laws of this
state.



                                      IV.

      The places where its principal business is to be transacted are Oklahoma
City, Oklahoma, and a business office or offices may be maintained in
__________________________________ and in such other places as the directors may
from time to time determine; and the meetings of stockholders and directors may
be held at such branch office or offices thus established.

                                       V.

      The number of directors of this corporation shall be three or more. The
names and residences of such directors who are to serve until the next election
are as follows:

                                                          Number of
         Name               Post Office Address      Shares Subscribed

     W. A. Quinn          Oklahoma City, Oklahoma          1700

     H. B. Howry          Oklahoma City, Oklahoma          1700

     D. N. Bell           Oklahoma City, Oklahoma          1700

                                      VI.

      The amount of the capital stock of this corporation shall be $100,000.00,
and shall be divided into 10,000 shares of $10.00 each.

      IN WITNESS WHEREOF, we have hereunto subscribed our names this 13th day of
September, 1937.

                                                           /s/ W. A. Quinn
                                                           ---------------------
                                                           /s/ H. B. Howry
                                                           ---------------------
                                                           /s/ D. N. Bell
                                                           ---------------------
                                                           _____________________

                                                           _____________________

                                      -2-


STATE OF OKLAHOMA          )
                           )  SS.
COUNTY OF OKLAHOMA         )

Personally appeared before me a Notary Public in and for said state, the above
named persons, to-wit: W. A. Quinn, H.B. Howry and D. N. Bell. who are
personally known to me to be the same persons who executed the foregoing
instrument of writing and duly acknowledged the execution of the same as their
free and voluntary act and deed for the uses and purposes therein set forth.

      Witness my hand and official seal this 13 day of September, 1937.

                                                      /s/ [Illegible]
                                                     ---------------------------
                                                               Notary Public

My commission expires the 4day of April, 1940.

                                      -3-


                        AMENDED ARTICLES OF INCORPORATION

STATE OF OKLAHOMA )
                  )  SS
OKLAHOMA COUNTY   )

TO THE SECRETARY OF STATE OF THE STATE OF OKLAHOMA:

         We, the undersigned,

         F. G. Baker, 513 N. Blackwelder, Oklahoma City, Oklahoma
         W. A. Quinn,1112 Belford, Oklahoma City, Oklahoma
         Marie B. Quinn, 431 N.W. 20th, Oklahoma City, Oklahoma

being the persons legally competent to amend the Articles of Incorporation
pursuant to the provisions of the Business Corporation Act of the State of
Oklahoma, do hereby execute the following amendment of the Articles of
Incorporation; and do further affirm that the amendment was adopted in the
manner prescribed by said Act.

                                   ARTICLE ONE

A. AS FILED:

      The name of this corporation is: Governair Corporation.

B. AMENDED:

      The name of this corporation is: Governair Corporation.

                                   ARTICLE TWO

A. AS FILED:

      The address of its Registered Office in the State of Oklahoma is: Oklahoma
City, County of Oklahoma, and the name and address of its Registered Agent is:
D. N. Bell.

B.  AS AMENDED:

      The address of its Registered Office in the State of Oklahoma is: 513
North Blackwelder, Oklahoma City, County of Oklahoma, and the name and address
of its Registered Agent is: W. A. Quinn, at said address.



                                 ARTICLE THREE

A. AS FILED:

      The duration of the corporation is Twenty years.

B. AMENDED:

      The duration of the corporation is twenty years, from November 1, 1948 to
November 1, 1968.

                                  ARTICLE FOUR

A. AS FILED:

      The purpose or purposes for which the corporation is formed are:
Manufacturing, Sale, Installation and Repair of Refrigerating and cooling units;
air purifying and heating units; and the doing of all things necessary to carry
out such purposes.

B. AMENDED:

      The purpose or purposes for which the corporation is formed are:


                        To carry on a general manufacturing business; to design,
                  patent, manufacture, assemble, buy, sell, distribute, own,
                  hold, demonstrate, install, maintain, operate, prepare, lease,
                  license, mortgage, import, export and in any other manner deal
                  in and deal with, as principal, agent, or otherwise, patented
                  articles, mechanical devices, machinery, appliances,
                  equipment, goods, wares and merchandise of every kind, nature
                  and character, together with raw materials, parts, supplies
                  and any other articles or things necessary, useful, or
                  desirable in connection therewith; to acquire by purchase,
                  lease or otherwise, erect, maintain, operate, own, hold,
                  lease, mortgage, sell, convey, exchange and in any other
                  manner deal in and deal with factories, manufacturing plants,
                  work shops, warehouses, stores and buildings of all kinds,
                  together with tools, machinery and equipment necessary or
                  desirable for the conduct of the business.

                        To purchase, take, own, hold, deal in, mortgage or
                  otherwise lien, and to lease, sell, exchange, convey, transfer
                  or in any manner whatever dispose of real property, within or
                  without the State of Oklahoma.

                                      -5-


                  To manufacture, purchase or otherwise acquire and to hold,
            own, mortgage or otherwise lien, pledge, lease, sell, assign,
            exchange, transfer or in any manner dispose of, and to invest, deal
            and trade in and with goods, wares, merchandise and personal
            property of any and every class and description, within or without
            the State of Oklahoma.

                  To acquire the good will, rights and property of, and to
            undertake the whole or any part of the assets and liabilities of any
            person, firm, association or corporation; to pay for the same in
            cash, the stock of this company, bonds or otherwise; to hold or in
            any manner to dispose of the whole or any part of the property so
            purchased; to conduct in any lawful manner the whole or any part of
            any business so acquired and to exercise all the powers necessary or
            convenient in and about the conduct and management of such business.

                  To guarantee, purchase or otherwise acquire, hold, sell,
            assign, transfer, mortgage, pledge or otherwise dispose of shares of
            the capital stock, bonds or other evidences of indebtedness created
            by other corporations and, while the holder of such stock, to
            exercise all the rights and privileges of ownership, including the
            right to vote thereon, to the same extent as a natural person might
            or could do.

                  To purchase or otherwise acquire, apply for, register, hold,
            use, sell or in any manner dispose of, and to grant licenses or
            other rights in and in any manner deal with, patents, inventions,
            improvements, processes, formulas, trademarks, trade names, rights
            and licenses secured under letters patent, copyrights or otherwise.

                  To enter into, make and perform contracts of every kind for
            any lawful purpose, with any person, firm, association or
            corporation, town, city, county, body politic, state, territory,
            government, or colony or dependency thereof.

                  To borrow money for any of the purposes of the corporation and
            to draw, make, accept, endorse, discount, execute, issue, sell,
            pledge or otherwise dispose of promissory notes, drafts, bills of
            exchange, warrants, bonds, debentures and other negotiable or
            non-negotiable, transferable or non-transferable instruments and
            evidences of indebtedness and to secure the payment thereof and the
            interest thereon by mortgage or pledge, conveyance or assignment in
            trust of the whole or any part of the property of the corporation at
            the time owned or thereafter acquired.

                                      -6-


                  To purchase, sell, lease, own, hold, deal in, exchange,
            convey, or transfer mineral interests, including oil and gas
            leasehold estates, royalties, oil payments and other interests in
            oil and gas properties, and to drill, exploit, develop, produce,
            operate, or otherwise handle such properties for its own account or
            in connection with others.

                  To purchase, hold, sell and transfer the shares of its capital
            stock.

                  To have one or more offices and to conduct any or all of its
            operations and business, and to promote its objects within or
            without the State of Oklahoma, without restriction as to place or
            amount.

                  To do all such other things as may not be in violation of the
            statutes of the United States of America or of the State of
            Oklahoma, as principal, agent, contractor, trustee, or otherwise,
            alone or in company with others.

                                  ARTICLE FIVE

A. AS FILED:

      The aggregate number of shares which the corporation shall have authority
to allot is 10,000 divided into one class. The designation of each class, the
number of shares of each class, and the par value of the shares of each class
are as follows:



                              NUMBER                                PAR VALUE
       CLASS                 OF SHARES                              PER SHARE
                                                              
      Common                  20,000                                 $10.00
                              20,000                                 $10.00


B. AS AMENDED:

               (No change from amendment of November 18, 1949.)

                                   ARTICLE SIX

A. AS FILED.

      The amount of stated capital with which it will begin business is
$5,000.00, which has been fully paid in.

                                      -7-


                                  ARTICLE SEVEN

A. AS FILED:

      The number and class of shares to be allotted by the corporation before it
shall begin business and the consideration to be received by the corporation
therefor, are:



                          NUMBER                  CONSIDERATION TO
CLASS OF SHARES          OF SHARES                  BE RECEIVED
                                            
    Common                20,000                    $200,000.00


(as shown by amendment of November 18, 1948. Original articles provided for
 5,100 shares.)

B. AMENDED:

      No change, except that the full amount of stock authorized has not been
issued.

                                 ARTICLE EIGHT

A. AS FILED:

      The number of directors to be elected at the first meeting of the
shareholders is three.

B. AMENDED: No change.

                               ARTICLE NINE

      Such amendment was proposed by a resolution of the Board of Directors on
Wednesday, March 19, 1952. The amendment was adopted by a vote of the
shareholders in accordance with the provisions of section 153 of the Oklahoma
Business Corporation Act, 1947. The meeting of the shareholders of the
corporation at which the amendment was adopted was held at 513 North
Blackwelder, in Oklahoma City, Oklahoma County, Oklahoma on Tuesday, April 8,
1952. Notice of the meeting was given the shareholders by mail for a period of
15 days. The number of shares voted for said amendment was 4488-1/3 shares,
being a majority of the issued and outstanding shares of stock.

                                      -8-


(Corporate Seal)
                                             GOVERNAIR CORPORATION

                                             By:/s/ F.G. Baker
                                                --------------------------
                                                    Its ___________President

ATTEST

/s/ Marie B. Quinn
- ---------------------
    Its Secretary

STATE OF OKLAHOMA )
                  )   SS
OKLAHOMA COUNTY   )

      I, the undersigned Notary Public in an for said County and State, hereby
certify that on 13th day of May, 1952, F.G. Baker and Marie B. Quinn, personally
appeared before me and being first duly sworn, acknowledged that they signed the
foregoing document in the respective capacities therein set forth and declared
that the statements therein contained are true.

      IN WITNESS WHEREOF, I have hereunto set my hand and seal the day and year
before written.

                                                      /s/ [Illegible]
                                                   -----------------------------
                                                          Notary Public

My commission expires:
 Sept. 11, 1952

                                      -9-


                        AMENDED ARTICLES OF INCORPORATION

STATE OF OKLAHOMA )
                  )  SS
OKLAHOMA COUNTY   )

TO THE SECRETARY OF STATE OF THE STATE OF OKLAHOMA:

     We, the undersigned,

     W. A. Quinn, 1112 Belford, Oklahoma City, Oklahoma
     Leonard H. Savage, 1209 Huntington Drive, Oklahoma City, Oklahoma
     W. H. McDonald, 1614 N.W. 42nd Place, Oklahoma City, Oklahoma
     C. K. Fitzgerald, 2926 N.W. 35th Street, Oklahoma City, Oklahoma
     Roy C. Lytle, 1304 Larchmont Lane, Oklahoma City, Oklahoma

being the persons legally competent to amend the Articles of Incorporation
pursuant to the provisions of the Business Corporation Act of the State of
Oklahoma, do hereby execute the following amendment of the Articles of
Incorporation, as previously amended; and do further affirm that the amendment
was adopted in the manner prescribed by said Act.

                                  ARTICLE ONE

A. AS FILED:

      The name of this corporation is: Governair Corporation.

B.  AMENDED:

      The name of this corporation is: Governair Corporation.

                                   ARTICLE TWO

A. AS PREVIOUSLY AMENDED:

      The address of its Registered Office in the State of Oklahoma is: 513
North Blackwelder, Oklahoma City, County of Oklahoma, and the name and address
of its Registered Agent is: W. A. Quinn, at said address.

B. AMENDED:

      No change.

                                      -10-


                                  ARTICLE THREE

A. AS PREVIOUSLY AMENDED:

      The duration of the corporation is twenty years, from November 1, 1948 to
November 1, 1968.

B. AMENDED:

      No change.

                                  ARTICLE FOUR

A. AS PREVIOUSLY AMENDED:

      The purpose or purposes for which the corporation is formed are:

                  To carry on a general manufacturing business; to design,
            patent, manufacture, assemble, buy, sell, distribute, own, hold,
            demonstrate, install, maintain, operate, prepare, lease, license,
            mortgage, import, export and in any other manner deal in and deal
            with, as principal, agent, or otherwise, patented articles,
            mechanical devices, machinery, appliances, equipment, goods, wares
            and merchandise of every kind, nature and character, together with
            raw materials, parts, supplies and any other articles or things
            necessary, useful or desirable in connection therewith; to acquire
            by purchase, lease, or otherwise, erect, maintain, operate, own,
            hold, lease, mortgage, sell, convey, exchange and in any other
            manner deal in and deal with factories, manufacturing plants, work
            shops, warehouses, stores and buildings of all kinds, together with
            tools, machinery and equipment necessary or desirable for the
            conduct of the business.

                  To purchase, take, own, hold, deal in, mortgage or otherwise
            lien, and to lease, sell, exchange, convey, transfer or in any
            manner whatever dispose of real property, within or without the
            State of Oklahoma.

                  To manufacture, purchase or otherwise acquire and to hold,
            own, mortgage or otherwise lien, pledge, lease, sell, assign,
            exchange, transfer or in any manner dispose of, and to invest, deal
            and trade in and with goods, wares, merchandise and personal
            property of any and every class and description, within or without
            the State of Oklahoma.

                                      -11-


                  To acquire the good will, rights and property of, and to
            undertake the whole or any part of the assets and liabilities of any
            person, firm, association or corporation; to pay for the same in
            cash, the stock of this company, bonds or otherwise; to hold or in
            any manner to dispose of the whole or any part of the property so
            purchased; to conduct in any lawful manner the whole or any part of
            any business so acquired and to exercise all the powers necessary or
            convenient in and about the conduct and management of such business.

                  To guarantee, purchase or otherwise acquire, hold, sell,
            assign, transfer, mortgage, pledge or otherwise dispose of shares of
            the capital stock, bonds or other evidence of indebtedness created
            by other corporations and, while the holder of such stock, to
            exercise all the rights and privileges of ownership, including the
            right to vote thereon, to the same extent as a natural person might
            or could do.

                  To purchase or otherwise acquire, apply for, register, hold,
            use, sell or in any manner dispose of, and to grant, licenses or
            other rights in and in any manner deal with, patents, inventions,
            improvements, processes, formulas, trademarks, trade names, rights
            and licenses secured under letters patent, copyrights or otherwise.

                  To enter into, make and perform contracts of every kind for
            any lawful purpose, with any person, firm, association or
            corporation, town, city, county, body politic, state, territory,
            government, or colony or dependency thereof.

                  To borrow money for any of the purposes of the corporation and
            to draw, make, accept, endorse, discount, execute, issue, sell,
            pledge or otherwise dispose of promissory notes, drafts, bills of
            exchange, warrants, bonds, debentures and other negotiable or
            non-negotiable, transferable or non-transferable instruments and
            evidences of indebtedness and to secure the payment thereof and the
            interest thereon my mortgage or pledge, conveyance or assignment in
            trust of the whole or any part of the property of the corporation at
            the time owned or thereafter acquired.

                  To purchase, sell, lease, own, hold, seal in, exchange,
            convey, or transfer mineral interests, including oil and gas
            leasehold estates, royalties, oil payments and other interests in
            oil and gas properties, and to drill, exploit, develop, produce,
            operate, or otherwise handle such properties for its own account or
            in connection with others.

                                      -12-


                  To purchase, hold, sell and transfer the shares of its capital
            stock.

                  To have one or more offices and to conduct any or all of its
            operations and business, and to promote its objects within or
            without the State of Oklahoma, without restriction as to place or
            amount.

                  To do all such other things as may not be violation of the
            statutes of the United States of America or of the State of
            Oklahoma, as principal, agent, contractor, trustee, or otherwise,
            alone or in company with others.

B.AMENDED:

      No change.

                                  ARTICLE FIVE

A. AS PREVIOUSLY AMENDED:

      The aggregate number of shares which the corporation shall have authority
to allot is 20,000 divided into one class. The designation of each class, the
number of shares of each class, and the par value of the shares of each class
are as follows:



                       NUMBER                    PAR VALUE
CLASS                OF SHARES                   PER SHARE
                                           
Common                 20,000                      $10.00


B. AMENDED:

      The aggregate number of shares which the corporation shall have authority
to allot is 200,000 shares all of the same class. The designation of the class,
the number of shares thereof, and the par value of the shares are as follows:



                      NUMBER                 PAR VALUE
CLASS                OF SHARES               PER SHARE
                                       
Common                200,000                50 cents


                                      -13-


                                   ARTICLE SIX

A. AS FILED:

      The amount of stated capital with which it will begin business if
$5,000.00, which has been fully paid in.

B. AMENDED:

      No change.

                                 ARTICLE SEVEN

A. AS PREVIOUSLY AMENDED:

      The number and class of shares to be allotted by the corporation before it
shall begin business and the consideration to be received by the corporation
therefor, are:



  CLASS                  NUMBER                           CONSIDERATION
OF SHARES              OF SHARES                         TO BE RECEIVED
                                                   
 Common                  20,000                            $200,000.00


(as shown by amended of November 18, 1948. Original articles provided for
5,100 shares.)

B. AMENDED:

      The number and class of shares to be allotted by the corporation after
this amendment, and the consideration previously received by the corporation
therefor, are:



  CLASS                 NUMBER                              CONSIDERATION
OF SHARES              OF SHARES                              RECEIVED
                                                      
  Common                200,000                              $100,000.00


                                 ARTICLE EIGHT

A. AS FILED:

      The number of directors to be elected at the first meeting of the
shareholders is three.

B. AMENDED:

      The number of directors to be elected is five.

                                      -14-


                                  ARTICLE NINE

      The above and foregoing amendment was proposed by a resolution of the
Board of Directors on Tuesday, July 12, 1955. The amendment was adopted by a
vote of the shareholders in accordance with the provision of Paragraph 153 of
the Oklahoma Business Corporation Act, 1947. The meeting of the shareholders of
the corporation at which the amendment was adopted was held at The First
National Bank and Trust Company in Oklahoma City, Oklahoma County, Oklahoma, on
Tuesday, July 12, 1955. Notice of the meeting was waived by all shareholders,
and the holders of all of the issued and outstanding shares of stock were
present and voted unanimously and affirmatively for the amendments herein set
forth.

      DATED at Oklahoma City, Oklahoma, this July 12, 1955.

                                                       GOVERNAIR CORPORATION

                                                       By:/s/ W. A. Quinn
                                                          ----------------------
                                                            Its President

(Corporate Seal)

ATTEST:

/s/ Jack A. Oliver
- -----------------------
      Its Secretary

                                      -15-


                        AMENDED ARTICLES OF INCORPORATION
                          AMENDING AND EXTENDING PRIOR
                        AMENDED ARTICLES OF INCORPORATION

STATE OF OKLAHOMA )
                  ) SS:
OKLAHOMA COUNTY   )

TO THE SECRETARY OF STATE OF THE STATE OF OKLAHOMA:

      We, the undersigned,

      W. A. Quinn, 4840 North Sewell, Oklahoma City, Oklahoma
      Leonard H. Savage, 1209 Huntington Drive, Oklahoma City, Oklahoma
      W. H. McDonald, 2217 N.W. 57th Street, Oklahoma City, Oklahoma
      C. K. Fitzgerald, 2530 N.W. 56th Street, Oklahoma City, Oklahoma
      Roy C. Lytle, 6806 N.W. Grand Boulevard, Oklahoma City, Oklahoma

being the persons legally competent to amend the Articles of Incorporation
pursuant to the provisions of the Business Corporation Act of the State of
Oklahoma, do hereby execute the following amendment to the Articles of
Incorporation, as previously amended; and do further affirm that the amendment
was adopted in the manner prescribed by said Act.

                                   ARTICLE ONE

A. AS FILED:

      The name of this corporation is GOVERNAIR CORPORATION.

B. AMENDED:

      No change.

                                  ARTICLE TWO

A. AS PREVIOUSLY AMENDED:

      The address of its Registered Office in the State of Oklahoma is: 513
North Blackwelder, Oklahoma City, County of Oklahoma, and the name and address
of its Registered Agent is: W. A. Quinn, at said address.

                                      -16-


B. AMENDED:

      The address of its Registered Office in the State of Oklahoma is: 4840
North Sewell, Oklahoma City, County of Oklahoma, and the name and address of its
Registered Agent is: W. A. Quinn, at said address.

                                 ARTICLE THREE

A. AS PREVIOUSLY AMENDED:

      The duration of the corporation is twenty years, from November 1, 1948 to
November 1, 1968.

B.  AMENDED:

      The duration of the corporation is fifty years, from November 1, 1948 to
November 1, 1998.

                                  ARTICLE FIVE

A. AS PREVIOUSLY AMENDED:

      The aggregate number of shares which the corporation shall have authority
to allot is 200,000 shares all of the same class. The designation of the class,
the number of shares thereof, and the par value of the shares are as follows:




                         NUMBER                          PAR VALUE
CLASS                  OF SHARES                         PER SHARE
                                                   
Common                  200,000                          50 cents


B. AMENDED:

      The aggregate number of shares which the corporation shall have authority
to allot is 400,000 shares, all of the same class. The designation of the class,
the number of shares thereof, and the par value of the shares are as follows:

                                      -17-




                         NUMBER                          PAR VALUE
CLASS                  OF SHARES                         PER SHARE
                                                   
Common                  400,000                           50 cents


                                  ARTICLE NINE

      The above and foregoing cover all the amendments to the Articles of
Incorporation, and any article not referred to above shall remain the same as
set forth in the Amended Articles of Incorporation dated July 12, 1955.

      The above and foregoing amendment was proposed by a resolution of the
Board of Directors on Friday, June 29, 1962. The amendment was adopted by a vote
of the shareholders in accordance with the provisions of Paragraph 153 of the
Oklahoma Business Corporation Act, 1947. The meeting of the shareholders of the
corporation at which the amendment was adopted was held at the office of the
corporation, 4840 North Sewell, Oklahoma City, Oklahoma, on Friday, June 29,
1962. Notice of the meeting was given to all shareholders, and the holders of
more than ninety (90%) percent of the issued and outstanding shares of stock
were present and voted unanimously and affirmatively for the amendments herein
set forth.

      DATED at Oklahoma City, Oklahoma, this 31st day of October, 1962.

                                                       GOVERNAIR CORPORATION

                                                       By /s/ W. A. Quinn
                                                          ----------------------
                                                                   President

ATTEST:

/s/ [Illegible]
- -----------------------
    Assistant Secretary

                                      -18-


STATE OF OKLAHOMA )
                  ) SS
OKLAHOMA COUNTY   )

      I, the undersigned Notary Public in an for said County and State, hereby
certify that on 31st day of October, 1962, W. A. Quinn and Roy C. Lytle,
personally appeared before me and being first duly sworn, acknowledged that they
signed the foregoing document in the respective capacities therein set forth and
declared that the statements therein contained are true.

      IN WITNESS WHEREOF, I have hereunto set my hand and seal the day and year
before written.

                                                       /s/ [Illegible]
                                                       -------------------------
                                                             Notary Public

My commission expires:
   Sept. 9, 1964

                                      -19-


                 AMENDED ARTICLES OF INCORPORATION AMENDING AND
                EXTENDING PRIOR AMENDED ARTICLES OF INCORPORATION

Secretary of State
State of Oklahoma
Corporation Division
State Capitol Building
2300 N. Walnut
Oklahoma City, Oklahoma 73105

      Pursuant to the Business Corporation Act of the State of Oklahoma, the
undersigned Corporation hereby certifies the following:

      1.    The present name of the Corporation is Governair Corporation. The
name under which it was originally incorporated was Governair Corporation.

      2.    An amendment to the Corporation's Articles of Incorporation, as
amended, was adopted by the Shareholders on January 14, 1985.

      3.    Article Number 3 currently reads as follows:

            The duration of the corporation is fifty years, from November 1,
      1948 to November 1, 1998.

      Article Number 8 currently reads as follows:

            The number of directors to be elected is five.

      4.    Article Number 3 is amended to read as follows: The duration of the
            corporation is perpetual. Article Number 8 currently reads as
            follows: The number of directors to be elected is three.

                                      -20-


      5.    Of the 380,000 shares outstanding, 380,000 of such shares were
entitled to vote on such amendment. The number of outstanding shares of any
class entitled to vote thereon as a class were as follows:



                                     Number of
Class                           Outstanding Shares
                             
Common                                380,000


      6.    The number of shares voted for and against the amendment was as
follows:



Class                  No. Voted For                No. Voted Against
                                              
Common                    380,000                            0


      7.    The amendment did not change the number or par value of authorized
shares having a par value. The amendment did not change the number of authorized
shares without par value.

      8.    The amendment did not provide for an exchange, reclassification, or
cancellation of issued shares or a reduction of the number of authorized shares
of any class below the number of issued shares of that class.

                                      -21-


STATE OF MISSOURI   )
                    )  SS:
COUNTY OF ST. LOUIS )

      I, Suzanne C. Parker, a Notary Public, do hereby certify that on this 14th
day of January, 1985, personally appeared before me Bernard L. Duchinsky who,
being by me first duly sworn, declare that he is the Chairman of Governair
Corporation, that he signed the foregoing document as Chairman of the
Corporation, and that the statements therein contained are true.

Notarial Seal                                           /s/ Suzanne C. Parker
                                                    ----------------------------
                                                        Notary Public

My commission expires:  June 26, 1988

                                      -22-


FEE:  $10.00

                              Change or Designation
                                       of
                                Registered Agent
                                     and/or
                                   Location of
                                Registered Office
                             (Oklahoma Corporation)

FILE IN DUPLICATE
PLEASE PRINT CLEARLY

PLEASE NOTE: This form MUST be filed with a letter from the Oklahoma Tax
Commission stating the franchise tax has been paid by the corporation for the
current fiscal year, with the exception of not for profit corporations.

TO:  THE OKLAHOMA SECRETARY OF STATE

      The undersigned, for the purpose of changing its registered agent and/or
registered office pursuant to Section 1023/1026 of the Oklahoma General
Corporation Act, hereby certifies:

1.    The name of the corporation is: Governair Corporation

2.    The location of the registered office of this corporation is:

      c/o The Prentice-Hall Corporation System, Oklahoma, Inc.
      115 S.W. 89th Street   Oklahoma City     Oklahoma          73139-8511
      --------------------------------------------------------------------------
      Street Address             City           County            Zip Code
      (P.O. Boxes are not acceptable.)

3.    The name of the registered agent at such address upon whom process against
      this corporation may be served is:

            The Prentice-Hall Corporation System, Oklahoma, Inc.

      IN WITNESS WHEREOF, said corporation has caused this certificate to be
signed by its Vice President and attested by its __________Secretary, this 10th
day of March 1993.

         /s/ Richard J. Harris                         Richard J. Harris
- --------------------------------------------    --------------------------------
by                       Vice President               (Please print name)

ATTEST:

         /s/ Kevin W. Donnelly                         Kevin W. Donnelly
- --------------------------------------------    --------------------------------



by        ____ Secretary                              (Please print name)

                                                          (FM0056-Revised 09/91)

                                      -24-