<PAGE>   1
                                                                  Exhibit 3.1

                          CERTIFICATE OF INCORPORATION
                                       OF
                              HMI INDUSTRIES INC.


                 FIRST:           The name of the company is HMI Industries Inc.

                 SECOND:          The address of its registered office in the
State of Delaware is No. 100 West Tenth Street, in the City of Wilmington,
County of New Castle.  The name of its registered agent at such address is The
Corporation Trust Company.

                 THIRD:           The nature of the business or purposes to be
conducted or promoted is:

                          To develop, manufacture, fabricate, assemble,
                 purchase or otherwise acquire, lease, rent, store,
                 sell, trade, exchange, job, import, export, deal in or deal
                 with, or transfer or otherwise dispose of vacuum cleaners and
                 other household and institutional appliances, and any
                 accessories, parts, aids, materials, liquids or solvents used
                 or usable in connection therewith.

                          To conduct any lawful business or to engage in any 
                 lawful act or activity for which corporations may be organized
                 under the General Corporation Law of Delaware.
        
                          To acquire, and pay for in cash, stock or bonds of
                 this corporation or otherwise, the good will, rights, assets
                 and property, and to undertake or assume the whole or any part
                 of the obligations or liabilities of any person, firm,
                 association or corporation.

                          To acquire, hold, use, sell, assign, lease, grant
                 licenses in respect of, mortgage or otherwise dispose of
                 letters patent of United States or any foreign country, patent
                 rights, licenses and privileges, inventions, improvements and
                 processes, copyrights, trademarks and trade names,     
                 relating to or useful in connection with any business of this
                 corporation.


                          To acquire by purchase, subscription or otherwise,
                 and to take receive, hold, own, use or otherwise employ,
                 guarantee, sell, assign, exchange, transfer, mortgage, pledge,
                 lend or otherwise dispose of or deal in and with any of the
                 shares of the capital stock, or any voting trust certificates
                 in respect of the shares of capital stock, scrip, warrants,
                 rights, bonds, debentures, notes, trust receipts, and other
                 securities, obligations, choses in action and evidences of
                 indebtedness or interest issued or created by any
                 corporations, joint stock companies, syndicates, associations,
                 firms, trusts or persons, public or private, or by the
                 governmental of the United States of America, or by any
                 foreign government, or by any state, territory, province,
                 municipality or other 




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                 political subdivision or by any government agency, and as
                 owner thereof to possess and exercise all the rights, powers
                 and privileges of ownership, do any and all acts and things
                 necessary or advisable for the preservation, protection,
                 improvement and enhancement in value thereof.

                          To borrow or raise money for any of the purposes of 
                 the corporation and, from time to time without limit as to
                 amount, to draw, make, accept, endorse, execute, issue and
                 deliver promissory notes, drafts, bills of exchange, warrants,
                 bonds, debentures and other negotiable or non-negotiable
                 instruments and evidences of indebtedness, and to secure the
                 payment and full performance of any thereof and of the
                 interest thereon by mortgage upon or pledge, conveyance or
                 assignment in trust of the whole or any part of the assets of
                 the corporation, whether real, personal or mixed (including
                 intangibles) and whether at the time owned or  thereafter
                 acquired, and to sell, pledge or otherwise dispose of such
                 promissory notes, bonds, debentures and other instruments or
                 obligations of the corporation for its corporate purposes.

                          To purchase, receive, take by grant, gift, devise, 
                 bequest or otherwise, lease, or otherwise acquire, own, hold,
                 improve, employ, use and otherwise deal in and with real or
                 personal property, or any interest therein, wherever situated,
                 and to sell, convey, lease, exchange, transfer, assign or
                 otherwise dispose of, or mortgage or pledge, all or any of the 
                 corporation's property and assets, or any interest therein,
                 wherever situated.

                          In general, to possess and exercise all the powers 
                 and privileges granted by the General Corporation Law of
                 Delaware or by any other law of Delaware or by this
                 certificate of incorporation together with any powers
                 incidental thereto, so far as such powers and privileges are
                 necessary or convenient to the conduct, promotion or
                 attainment of the business or  purposes of the corporation.

                          The business and purposes specified in the foregoing 
                 clauses shall, except where otherwise expressed, be in no way
                 limited or restricted by reference to, or inference from, the
                 terms of any other clause in this certificate of
                 incorporation, but business and purposes specified in each of
                 the foregoing clauses of this article shall be regarded as     
                 independent business and purposes.


                 FOURTH:          The total number of shares of capital
                 stock which the corporation shall have authority to issue is
                 ten million three hundred thousand (10,300,000) shares, of
                 which ten million (10,000,000) shares shall be common stock
                 having a par value of One Dollar ($1.00) per share and three
                 hundred thousand (300,000) shares shall be preferred stock
                 having a par value of Five Dollars ($5.00) per share.  Subject
                 to the requirement of Section 242 (d) (1) of the General
                 Corporation Law of Delaware, the authorized number of shares
                 of either common or preferred stock may be increased or
                 decreased by the affirmative vote 





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                 (taken without regard to class) of the holders of a
                 majority of the capital stock of the corporation entitled to
                 vote.  The common stock and the preferred stock may be issued
                 in classes or series from time to time with such voting powers
                 and such designations, preferences, and relative,
                 participation, optional or other special rights, and
                 qualifications, limitations or restrictions thereof, as shall
                 be stated and expressed in the resolution or resolutions
                 providing for the issue of such common stock or preferred
                 stock or any class or series thereof adopted by the Board of
                 Directors pursuant to the authority hereby vested in it. 
                 Without limitation on the generality of the foregoing, the
                 common stock and the preferred stock, and any class or series
                 thereof, may have such voting powers, full or limited, or no
                 voting powers, as shall be stated and expressed in the
                 resolution or resolutions adopted by the Board of Directors
                 providing for the issue of such common stock or preferred
                 stock, or any class or series thereof. The preferred stock, or
                 any class of series thereof, may be made subject to redemption
                 at such time or times and at such price or prices, may be made
                 convertible into, or exchangeable for, shares of any other
                 class or classes or of any other series of any class of stock
                 of the corporation at such price or prices or at such rates of
                 exchange and with such adjustments, and shall be subject to
                 such provisions as to reissue upon redemption or purchase by
                 or surrender to the corporation, including the prohibition
                 thereof, as shall be stated and expressed in the resolution or
                 resolutions adopted by the Board of Directors providing for
                 the issue of such preferred stock or any class or series
                 thereof; and further, each holder of such preferred stock and
                 of any class or series thereof shall be entitled to receive
                 dividends at such rates, on such conditions, with such
                 preferences (whether cumulative or noncumulative) and at such
                 times, and to have such rights upon the dissolution of, or
                 upon any distribution of assets of, the corporation, as shall
                 also be stated and expressed in the said resolution or 
                 resolutions adopted by the Board of Directors as aforesaid.

                 FIFTH:           The name and mailing address of the 
incorporation is as follows:

     Name                         Mailing Address
     ----                         ---------------

     Charles D. Leist             135 W. LaSalle Street, Chicago, Illinois
                                  60603

                 SIXTH:           The board of directors shall initially 
consist of three members, the same being:

     Name                         Mailing Address
     ----                         ---------------

     Frank C. Callahan            203 N. Wabash Avenue, Chicago, Illinois 60601
     Albert E. Kramer             203 N. Wabash Avenue, Chicago, Illinois 60601
     George P. Brit               203 N. Wabash Avenue, Chicago, Illinois 60601

                 SEVENTH:                  The corporation is to have perpetual
existence.





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                 EIGHTH:          In furtherance and not in limitation of the
powers conferred by statute, the board of directors is expressly authorized:

                                  To make, alter or repeal the by-laws of the   
                 corporation.

                                  To authorize and cause to be executed
                 mortgages and liens upon the real and personal property of the 
                 corporation.

                                  To set apart out of any of the funds of the
                 corporation available for dividends a reserve or reserves for
                 any proper purpose and to abolish any such reserve in the      
                 manner in which it was created.

                                  By a majority of the whole board, to
                 designate one or more committees, each committee to consist of
                 two or more of the directors of the corporation.  The board
                 may designate one or more directors as alternate members of
                 any committee, who may replace any absent or disqualified
                 member at any meeting of the committee.  Any such committee,
                 to the extent provided in the resolution or in the by-laws of
                 the corporation, shall have and may exercise the powers of the
                 board of directors in the management of the business and
                 affairs of the corporation, and may authorize the seal of the
                 corporation to be affixed to all papers which may require it;
                 provided, however, the by-laws may provide that in the absence
                 or disqualification of any member of such committee or
                 committees, the member or members thereof present at any
                 meeting and not disqualified from voting, whether or not he or
                 they constitute a quorum, may unanimously appoint another
                 member of the board of directors to act at the meeting in the
                 place of any such absent or disqualified member.

                 NINTH:           Each member of the board of directors and of
       any committee designated by the board of directors shall, in the
       performance of his duties, be fully protected in relying in good faith
       upon the books of account or reports made to the corporation by any of
       its officers, or by an independent certified public accountant, or by an
       appraiser selected with reasonable care by the board of directors or by
       any such committee, or in relying in good faith upon other records of
       the corporation.

                 TENTH:           Meetings of stockholders may be held within
       or without the State of Delaware, as the by-laws may provide.  The
       books of the corporation may be kept (subject to any provision contained
       in the statutes) outside the State of Delaware at such place or places
       as may be designated from time to time by the board of directors or in
       the by-laws of  the corporation.

                 ELEVENTH:        The corporation reserves the right to
       amend, alter, change or repeal any provision contained in this
       certificate of incorporation, in the manner now or hereafter prescribed
       by statute, and all rights conferred upon stockholders herein are
       granted subject to this reservation.





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                 TWELFTH:         In the event that any  Business Combination
       with any Related Person has not been approved, adopted or authorized by
       the affirmative vote of two-thirds of the Continuing Directors, the
       terms of such Business Combination either must be approved, adopted or
       authorized by at least 80% of the Voting Stock entitled to be voted
       (regardless of whether or not any vote of stockholders of the corporation
       is otherwise required by law or agreement), or must provide that the
       holders of all shares of each class, and of each series of each class,
       of outstanding Voting Stock shall be entitled to receive (and such
       Related Person shall be obligated to assure the receipt of) cash,
       securities and other property having a fair value as determined by a
       majority of the Continuing Directors, and Other Consideration, if any,
       of aggregate value per share not less than the higher of (1) the highest
       prices per share that such Related Person paid to acquire any shares of
       such class or series, as the case may be, pursuant to a tender offer,
       cash purchase, open market transaction or privately negotiated sale not
       effected on the open market at any time prior to the record date set to
       determine the stockholders entitled to vote on the proposed Business
       Combination, and (2) the Highest Recent Price per share.

                      For the purposes of this article twelfth:


                          (I)  The term 'Business Combination' shall mean (a)
                      any merger, consolidation or exchange of shares of the
                      corporation and/or any of its subsidiaries with or into,
                      or proposed by or on behalf of, any Related Person,
                      regardless of which entity is the survivor; (b) any sale,
                      lease, exchange, transfer, mortgage or any other security
                      device, or other disposition of assets (other than the
                      sales of products or services in the ordinary course of
                      business) of the corporation (including any securities of
                      subsidiaries) and/or any of its subsidiaries collectively
                      having an aggregate net book value exceeding 50% of the
                      stockholders' equity in the corporation according to the
                      corporation's most recently published annual or quarterly
                      consolidated balance sheet, to any Related Person, in one
                      or more transactions; (C) any sale, lease, exchange,
                      transfer, mortgage or any other security device, or other
                      disposition, of assets having a fair value, as determined
                      by a majority of the Continuing Directors, exceeding 50%
                      of the stockholder's equity in the corporation according
                      to its most recently published annual or quarterly
                      balance sheet, by any Related Person, or proposed by or
                      on behalf of any Related Person, to corporation and/or
                      any of its subsidiaries; (d) any issuance or transfer of
                      any securities of the corporation and/or any of its
                      subsidiaries by the Corporation and/or any of its
                      subsidiaries to any Related Person, other than pro rata
                      to all stockholders of the corporation; (e) any
                      reclassification of shares or recapitalization of the
                      corporation or any of its subsidiaries that would have
                      the effect of increasing the voting power of any Related
                      Person in the corporation, other than solely by
                      fractional share settlements in a pro rata stock dividend
                      or split; (f) any issuance or transfer of any securities
                      of any Related Person to the corporation and/or any of
                      its subsidiaries, other than pro rata to all stockholders
                      of the Related Person; (g) any liquidation or dissolution
                      of the corporation proposed by or on behalf of any
                      Related Person; or (h) any plan, 





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                      agreement, contract, proposal or other arrangement
                      providing for any of the above transactions.

                          (ii) The term 'Related Person' shall mean and include
                      collectively (a) any Person which, alone or together with
                      its Affiliates and Associates, Beneficially Owns shares
                      of capital stock of the corporation having more than 15%
                      of the voting power of the outstanding Voting Stock of
                      Corporation, (b) any Affiliate or Associate of any such
                      Persons, and (C) any other person with which such Person
                      or any of  its Affiliates or Associates has any
                      agreement, arrangement or understanding for the purpose
                      of acquiring, holding, voting or disposing of Voting
                      Stock of the corporation.

                          (iii) The term 'Person' shall mean and include any
                      individual, corporation, partnership, firm, association,
                      trust or other person or entity or group (whether or
                      not it has a legal identity).

                          (iv) The term 'Affiliate' shall mean any Person that
                      directly, or indirectly through one or more
                      intermediaries, controls, or is   controlled by, or is
                      under common control with, a specified Person.

                          (v) The term 'Associate' shall mean (i) any person of
                      which a specified Person is a director, officer or
                      partner or is, directly or indirectly, the Beneficial
                      Owner of 10% or more of any class of its equity
                      securities, (ii) any trust or other estate in which a
                      specified Person has a substantial beneficial interest or
                      as to which such specified Person serves as trustee or in
                      a similar capacity, and (iii) any relative or spouse of a 
                      specified Person, or any relative of such spouse.

                         (vi) The terms  'Beneficially Owns' and 'Beneficial 
                      Owner' shall refer to either or both of the following
                      powers possessed by any person, directly or indirectly,
                      through any contract, arrangement, understanding,
                      relationship, or otherwise, either alone or shared with
                      others:  (a) voting power, including the power to vote,
                      or to direct the voting of, a security; or (b) investment
                      power, including either a right to acquire or the power
                      to dispose of, or to direct the acquisition or
                      disposition of, a security.

                        (vii) The term 'Voting Stock' shall mean all outstanding
                      shares of capital stock to the corporation entitled to
                      vote generally in the election of Directors, other than
                      any stock having such right only by reason of the
                      occurrence of a contingency.

                       (viii) The term 'Continuing Director' shall mean a 
                      Director who is not a Related Person and who was not
                      proposed for election as a Director by or on behalf
                      of a Related Person.





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                         (ix) The term 'Highest Recent Price' of any class or
                      series of Voting Stock shall mean the highest sale price
                      reported during the 30 day period immediately preceding
                      the date in question of a share of such stock on the
                      Composite Tape for American Stock Exchange-Listed Stocks,
                      or if such stock is not quoted on such Composite Tape, on
                      the American Stock Exchange, or if such stock is not
                      listed on such Exchange, on the principal United States
                      securities exchange registered under the Securities
                      Exchange Act of 1934 on which such stock is listed, or,
                      if such stock is not listed on any such exchange, the
                      highest asked quotation for a share of such stock
                      reported during the 30-day period preceding the date in
                      question on the National Association of Securities
                      Dealers, Inc.  Automated Quotations Systems or any system
                      then in use, or if no such quotations are available, the
                      fair value on the date in question of a share of such
                      stock as determined by a majority of Continuing   
                      Directors.

                        (x) The term 'Other Consideration' shall apply in a 
                      Business Combination in which the corporation is the
                      surviving or acquiring corporation, and shall mean the
                      stock of the corporation retained by its existing public  
                      stockholders.

                      Continuing Directors, in making determinations pursuant   
to this article twelfth, may engage for the account of the corporation such
persons, including investment banking firms and the independent accountants who
have reported on the most recent audited financial statements of the
corporation, and utilize employees and agents of the corporation, who will in
the judgment of the Continuing Directors, be of assistance of them.  Any such
determination when made in good faith of the basis of such information and
assistance as was then reasonably available for such purpose, shall be
conclusive and binding upon the corporation and its stockholders.

                      THIRTEENTH:      No action that requires the vote or
consent of stockholders of the corporation may be taken without a meeting
and vote of stockholders.

                      FOURTEENTH:      Notwithstanding any other provisions of
this certificate of incorporation or the bylaws of the corporation (and
notwithstanding the fact that a lesser percentage may be specified by law, this
certificate of incorporation or the by-laws of the corporation), the amendment
or repeal of article twelfth, thirteenth or fourteenth of this certificate of
incorporation shall require the affirmative vote of the holders of shares
representing at least 80% of the shares of Voting Stock as defined in article
twelfth entitled to be voted thereon.

                        
                      FIFTEENTH:       No director of the corporation shall be
liable to the corporation or its stockholders for monetary damages for breach
of fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to the corporation or its stockholders; (ii) for
acts or omission not in good faith or which involve intentional misconduct or
knowing violation of law; (iii) under Section 174 of the Delaware General
Corporation Law relating to unlawful payment of a dividend or unlawful stock
purchase 




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or redemption; or (iv) for any transaction from which the director derived an
improper personal benefit.

                      THE UNDERSIGNED, being the incorporator hereinbefore
named, for the purpose of forming a corporation pursuant to the General
Corporation Law of the State of Delaware, makes this certificate, hereby
declaring and certifying that this is my act and deed and the facts herein
stated are true, and accordingly have hereunto set my hand this 11th day of
October, 1968.


/s/ Charles D.Leist 
------------------
Incorporator


STATE OF ILLINOIS)
                 )  SS
COUNTY OF COOK   )


        BE IT REMEMBERED  that on this 11th day of October, A.D., 1968,
personally came before me, a Notary Public for the State of Illinois,  Charles
D. Leist, the party to the foregoing certificate of incorporation, known to me
personally to be such, and acknowledge the said certificate to be his act and
deed and that the facts stated therein are true.

        GIVEN under my hand and seal of office the day and year aforesaid.

                                                   /s/ Louise G. Walker
                                                   --------------------
                                                        Notary Public





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