UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Act of 1934 (Amendment No. ) BROOKS AUTOMATION, INC. (BRKS) (Name of Issuer) Common Stock (Title of Class of Securities) 114340102 (CUSIP Number) David Nierenberg The D3 Family Funds 19605 NE 8th Street Camas, WA 98607 360-604-8600 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) July 11, 2005 (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D and is filing this schedule because of ss.ss.240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box: |_| -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSON The D3 Family Fund, L.P. (David Nierenberg is president of the General Partner, which is Nierenberg Investment Management Company.) -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |X| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC -------------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| -------------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION USA -------------------------------------------------------------------------------- 7 SOLE VOTING POWER 1,145,856 common shares (2.5%) ----------------------------------------------------------------- NUMBER OF 8 SHARED VOTING POWER SHARES BENEFICIALLY 0 OWNED BY ----------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER REPORTING PERSON 1,145,856 WITH ----------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,321,156 shares (5.1%) -------------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.1% -------------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! 2 -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSON The D3 Family Retirement Fund, L.P. (David Nierenberg is president of the General Partner, which is Nierenberg Investment Management Company.) -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |X| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC -------------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| -------------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION USA -------------------------------------------------------------------------------- 7 SOLE VOTING POWER 355,400 common shares (0.79%) ----------------------------------------------------------------- NUMBER OF 8 SHARED VOTING POWER SHARES BENEFICIALLY 0 OWNED BY ----------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER REPORTING PERSON 355,400 WITH ----------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,321,156 shares (5.1%) -------------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.1% -------------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! 3 -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSON The D3 Children's Fund, L.P. (David Nierenberg is president of the General Partner, which is Nierenberg Investment Management Company.) -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |X| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC -------------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| -------------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION USA -------------------------------------------------------------------------------- 7 SOLE VOTING POWER 85,400 common shares (0.19%) ----------------------------------------------------------------- NUMBER OF 8 SHARED VOTING POWER SHARES BENEFICIALLY 0 OWNED BY ----------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER REPORTING PERSON 85,400 WITH ----------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,321,156 shares (5.1%) -------------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.1% -------------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! 4 -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSON The D3 Offshore Fund, L.P. (David Nierenberg is president of the General Partner, which is Nierenberg Investment Management Company.) -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |X| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC -------------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| -------------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION USA -------------------------------------------------------------------------------- 7 SOLE VOTING POWER 558,900 common shares (1.23%) ----------------------------------------------------------------- NUMBER OF 8 SHARED VOTING POWER SHARES BENEFICIALLY 0 OWNED BY ----------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER REPORTING PERSON 558,900 WITH ----------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,321,156 shares (5.1%) -------------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.1% -------------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! 5 -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSON The D3 Family Bulldog Fund, L.P. ((David Nierenberg is president of the General Partner, which is Nierenberg Investment Management Company.) -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |X| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC -------------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e) |_| -------------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION USA -------------------------------------------------------------------------------- 7 SOLE VOTING POWER 175,600 common shares (0.39%) ----------------------------------------------------------------- NUMBER OF 8 SHARED VOTING POWER SHARES BENEFICIALLY 0 OWNED BY ----------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER REPORTING PERSON 175,600 WITH ----------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER 0 -------------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,321,156 shares (5.1%) -------------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* |_| -------------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.1% -------------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! 6 Item 1. Security and Issuer. Common stock in BROOKS AUTOMATION, INC. (BRKS) 15 Elizabeth Drive , Chelmsford, MA 01824-4111. Item 2. Identity and Background. The D3 Family Fund, L.P. is a Washington State limited partnership, whose principal business is investing in the equities of public micro-cap issuers. Located at 19605 N.E. 8th St., Camas, Washington 98607. No convictions or administrative proceedings as described in 2 (d) and (e). Item 3. Source and Amount of Funds or Other Consideration Source of funds is money invested in the partnership by its partners. Item 4. Purpose of Transaction We support the merger of Brooks Automation, Inc. and Helix Technology. Item 5. Interest in Securities of the Issuer. (a,b) The D3 Family Fund, L.P. owns and has sole voting and dispositive power over 1,145,856 common shares of BRKS. (c) Date Shares Bought Price ---- ------------- ----- 7/11/05 90,300 14.66 (d) N/A (e) N/A Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. N/A Item 7. Material to be Filed as Exhibits N/A 7 SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in the Statement is true, complete and correct. July 11, 2005 /s/ DAVID NIERENBERG ------------- ------------------------------------- David Nierenberg President Nierenberg Investment Management Company, Inc., the General Partner of The D3 Family Retirement Fund, L.P 8 Item 1. Security and Issuer. Common stock in BROOKS AUTOMATION, INC. (BRKS) 15 Elizabeth Drive, Chelmsford, MA 01824-4111. Item 2. Identity and Background. The D3 Family Retirement Fund, L.P. is a Washington State limited partnership, whose principal Business is investing in the equities of public micro-cap issuers. Located at 19605 N.E. 8th St., Camas, Washington 98607. No convictions or administrative proceedings as described in 2 (d) and (e). Item 3. Source and Amount of Funds or Other Consideration Source of funds is money invested in the partnership by its partners. Item 4. Purpose of Transaction We support the merger of Brooks Automation, Inc. and Helix Technology. Item 5. Interest in Securities of the Issuer. (a,b) The D3 Family Retirement Fund, L.P. owns and has sole voting and dispositive power over 355,400 common shares of BRKS. (c) Date Shares Bought Price ---- ------------- ----- 7/11/05 21.90 14.66 (d) N/A (e) N/A Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. N/A Item 7. Material to be Filed as Exhibits N/A 9 Signature After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. July 11, 2005 /s/ DAVID NIERENBERG ------------- ------------------------------------------ Date David Nierenberg President Nierenberg Investment Management Company, Inc., the General Partner of the D3 Family Retirement Fund, L.P. 10 Item 1. Security and Issuer. Common stock in BROOKS AUTOMATION, INC. (BRKS) 15 Elizabeth Drive , Chelmsford, MA 01824-4111. Item 2. Identity and Background. The D3 Children's Fund, L.P. is a Washington State limited partnership, whose principal business is investing in the equities of public micro-cap Issuers. Located at 19605 N.E. 8th St., Camas,Washington 98607. No convictions or administrative proceedings as described in 2 (d) and (e). Item 3. Source and Amount of Funds or Other Consideration Source of funds is money invested in the partnership by its partners. Item 4. Purpose of Transaction We support the merger of Brooks Automation, Inc. and Helix Technology. Item 5. Interest in Securities of the Issuer. (a,b) The D3 Children's Fund, L.P. owns and has sole voting and dispositive power over 175,600 common shares of BRKS. (c) Date Shares Bought Price ---- ------------- ----- 6/15/05 1,000 15.64 7/11/05 14,000 14.66 (d) N/A (e) N/A Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. N/A Item 7. Material to be Filed as Exhibits N/A 11 SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in the Statement is true, complete and correct. July 11, 2005 /s/ DAVID NIERENBERG ------------- ------------------------------------- David Nierenberg President Nierenberg Investment Management Company, Inc., the General Partner of The D3 Children's Fund, L.P. 12 Item 1. Security and Issuer. Common stock in BROOKS AUTOMATION, INC. (BRKS) 15 Elizabeth Drive , Chelmsford, MA 01824-4111. Item 2. Identity and Background. The D3 Offshore Fund, L.P. is a Washington State limited partnership, whose principal business is investing in the equities of public micro-cap issuers. Located at 19605 N.E. 8th St., Camas, Washington 98607. No convictions or administrative proceedings as described in 2 (d) and (e). Item 3. Source and Amount of Funds or Other Consideration Source of funds is money invested in the partnership by its partners. Item 4. Purpose of Transaction We support the merger of Brooks Automation, Inc. and Helix Technology. Item 5. Interest in Securities of the Issuer. (a,b) The D3 Offshore Fund, L.P. owns and has sole voting and dispositive power over 558,900 common shares of BRKS. (c) Date Shares Bought Price ---- ------------- ----- 5/18/05 40,000 14.29 5/23/05 30,000 14.42 5/24/05 5,700 14.38 5/25/05 7,000 14.28 6/1/05 10,000 15.38 6/2/05 10,000 15.62 6/3/05 25,000 15.29 6/6/05 43,500 15.05 6/7/05 20,000 15.22 6/8/05 15,000 15.29 6/9/05 5,000 15.36 6/13/05 10,000 15.73 6/14/05 22,000 15.74 6/15/05 4,400 15.62 6/24/05 10,000 15.33 7/11/05 102,300 14.66 (d) N/A (e) N/A 13 Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. N/A Item 7. Material to be Filed as Exhibits N/A SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in the Statement is true, complete and correct. July 11, 2005 /s/ DAVID NIERENBERG ------------- ------------------------------------- David Nierenberg President Nierenberg Investment Management Company, Inc., the General Partner of the D3 Offshore Fund, L.P. 14 Item 1. Security and Issuer. Common stock in BROOKS AUTOMATION, INC. (BRKS) 15 Elizabeth Drive , Chelmsford, MA 01824-4111. Item 2. Identity and Background. The D3 Family Bulldog Fund, L.P. is a Washington State limited partnership, whose principal business is investing in the equities of public micro-cap issuers. Located at 19605 N.E. 8th St., Camas,Washington 98607. No convictions or administrative proceedings as described in 2 (d) and (e). Item 3. Source and Amount of Funds or Other Consideration Source of funds is money invested in the partnership by its partners. Item 4. Purpose of Transaction We support the merger of Brooks Automation, Inc. and Helix Technology. Item 5. Interest in Securities of the Issuer. (a,b) The D3 Family Bulldog Fund, L.P. owns and has sole voting and dispositive power over 175,600 common shares of BRKS. (c) Date Shares Bought Price ---- ------------- ----- 6/14/05 18,000 15.74 7/11/05 20,800 14.66 (d) N/A (e) N/A Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer. N/A Item 7. Material to be Filed as Exhibits N/A 15 SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in the Statement is true, complete and correct. July 11, 2005 /s/ DAVID NIERENBERG ------------- ------------------------------------- David Nierenberg President Nierenberg Investment Management Company, Inc., the General Partner of The D3 Family Bulldog Fund, L.P. 16