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UNITED STATES |
OMB APPROVAL OMB Number: 3235-0145 Estimated average burden |
SCHEDULE
13G
Under the Securities Exchange Act of 1934
(Amendment No. 6)
(Title of Class of Securities)
(Date of Event Which Requires Filing of this Statement)
Check
the appropriate box to designate the rule pursuant to which this Schedule is filed:
[X ] Rule
13d-1(b)
[X ] Rule 13d-1(c)
[
] Rule 13d-1(d)
* The remainder of this cover page
shall be filled out for a reporting person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would alter the disclosures provided in
a prior cover page.
The information required in the remainder of this cover page
shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or
otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of
the Act (however, see the Notes).
Potential
persons who are to respond to the collection of information contained in this form are not required to respond
unless the form displays a currently valid OMB control number.
SEC Page 1 of 10
CUSIP No. 019645506
1. Names
of Reporting Persons.
Palo Alto Investors, LLC
2. Check
the Appropriate Box if a Member of a Group (See Instructions)
(a)
(b) X
4. Citizenship or Place of Organization California
Number of |
5. Sole Voting Power 0 |
6. Shared Voting Power 2,873,874 |
|
7. Sole Dispositive Power 0 |
|
8. Shared Dispositive Power 2,873,874 |
9. Aggregate Amount Beneficially Owned by Each Reporting Person 2,873,874
10. Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions) ______
11. Percent of Class Represented by Amount in Row (9) 8.1%
12. Type of Reporting Person (See Instructions) OO, IA
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CUSIP No. 019645506
1. Names
of Reporting Persons.
Palo Alto Investors
2. Check
the Appropriate Box if a Member of a Group (See Instructions)
(a)
(b) X
4. Citizenship or Place of Organization California
Number of |
5. Sole Voting Power 0 |
6. Shared Voting Power 2,873,874 |
|
7. Sole Dispositive Power 0 |
|
8. Shared Dispositive Power 2,873,874 |
9. Aggregate Amount Beneficially Owned by Each Reporting Person 2,873,874
10. Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions) ______
11. Percent of Class Represented by Amount in Row (9) 8.1%
12. Type of Reporting Person (See Instructions) CO, HC
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CUSIP No. 019645506
1. Names
of Reporting Persons.
William Leland Edwards
2. Check
the Appropriate Box if a Member of a Group (See Instructions)
(a)
(b) X
4. Citizenship or Place of Organization U.S.A.
Number of |
5. Sole Voting Power 6,500 |
6. Shared Voting Power 2,873,874 |
|
7. Sole Dispositive Power 6,500 |
|
8. Shared Dispositive Power 2,873,874 |
9. Aggregate Amount Beneficially Owned by Each Reporting Person 2,880,374
10. Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions) ______
11. Percent of Class Represented by Amount in Row (9) 8.1%
12. Type of Reporting Person (See Instructions) IN, HC
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CUSIP No. 019645506
1. Names
of Reporting Persons.
Anthony Joonkyoo Yun, MD
2. Check
the Appropriate Box if a Member of a Group (See Instructions)
(a)
(b) X
4. Citizenship or Place of Organization U.S.A.
Number of |
5. Sole Voting Power 0 |
6. Shared Voting Power 2,873,874 |
|
7. Sole Dispositive Power 0 |
|
8. Shared Dispositive Power 2,873,874 |
9. Aggregate Amount Beneficially Owned by Each Reporting Person 2,873,874
10. Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions) ______
11. Percent of Class Represented by Amount in Row (9) 8.1%
12. Type of Reporting Person (See Instructions) IN, HC
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CUSIP No. 019645506
1. Names
of Reporting Persons.
Palo Alto Small Cap Master Fund, L.P.
2. Check
the Appropriate Box if a Member of a Group (See Instructions)
(a)
(b) X
4. Citizenship or Place of Organization Cayman Islands
Number of |
5. Sole Voting Power 0 |
6. Shared Voting Power 1,348,941 |
|
7. Sole Dispositive Power 0 |
|
8. Shared Dispositive Power 1,348,941 |
9. Aggregate Amount Beneficially Owned by Each Reporting Person 1,348,941
10. Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See
Instructions) ______
11. Percent of Class Represented by Amount in Row (9) 3.8%
12. Type of Reporting Person (See Instructions) PN
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CUSIP No. 019645506
(a) Name
of Issuer
Allis-Chalmers Energy Inc.
(b) Address
of Issuer's Principal Executive Offices
5075 Westheimer, Suite 890, Houston, TX 77056
(a) The
names of the persons filing this statement are:
Palo Alto Investors, LLC ("PAI")
Palo Alto Investors
William Leland Edwards
Anthony
Joonkyoo Yun, MD
Palo Alto Small Cap Master Fund, L.P. (the "Master Fund")
(collectively, the "Filers").
(b) The
principal business office of the Filers except the Master Fund is located at:
470 University Avenue, Palo Alto, CA 94301
The principal business office of the Master Fund at:
Citco Fund Services (Bermuda) Limited, Washington Mall West, 2nd Floor, 7 Reid Street, Hamilton HM 11, Bermuda
(c) For citizenship of Filers, see Item 4 of the cover sheet for each Filer.
(d) This statement relates to shares of Common Stock of the Issuer (the "Stock").
(e) The CUSIP number of the Issuer is: 019645506
Item 3. If this statement is filed pursuant to rule 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
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CUSIP No. 019645506
(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).
(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).
(e) [ x ] An investment adviser in accordance with section 240.13d-1(b)(1)(ii)(E) (as to PAI).
(f) [ ] An employee benefit plan or endowment fund in accordance with section 240.13d-1(b)(1)(ii)(F).
(g) [ x ] A parent holding company or control person in accordance with 240.13d-1(b)(1)(ii)(G) (as to Palo Alto Investors, Mr. Edwards and Dr. Yun).
(h) [ ] A savings association as defined in section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813).
(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3).
(j) [ ] A non-U.S. institution in accordance with §240.13d-1(b)(ii)(J).
(k) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(K).
If filing as a non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution _______________________________________________________________.
See Items 5-9 and 11 of the cover page for each Filer.
Item 5. Ownership of Five Percent or Less of a Class
If
this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be
the beneficial owner of more than five percent of the class of securities, check the following [X].*
*The
Master Fund no longer holds more than 5% of the Stock and therefore will no longer file reports under Section
13(d) of the Act with respect to the Stock unless it is otherwise required to do so.
Item 6. Ownership of More than Five Percent on Behalf of Another Person.
PAI
is a registered investment adviser and is the general partner and investment adviser of the Master Fund and the
Fund and other investment limited partnerships and is the investment adviser to other investment funds. PAI's
clients have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the
sale of, the Stock. No client separately holds more than five percent of the outstanding Stock.
Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company.
Item 8. Identification and Classification of Members of the Group.
Palo
Alto Investors is the manager of PAI. Mr. Edwards is the controlling shareholder of Palo Alto Investors. Dr.
Yun is the President of PAI and Palo Alto Investors. The Filers are filing this Schedule 13G jointly, but not as
members of a group, and each of them expressly disclaims membership in a group. Each of PAI, Palo Alto
Investors, Mr. Edwards and Dr. Yun disclaims beneficial ownership of the Stock, except to the extent of that
person's pecuniary interest therein. In addition, the filing of this Schedule 13G on behalf of the Master Fund
should not be construed as an admission that it is, and it disclaims that it is, the beneficial owner, as defined
in Rule 13d-3 under the Securities Exchange Act of 1934, of any of the Stock covered by this Schedule 13G.
Item 9. Notice of Dissolution of Group
Certification of Palo Alto Investors, PAI, Mr. Edwards and Dr. Yun:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.
Certification of the Master Fund:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.
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CUSIP No. 019645506
Exhibit
A Joint Filing Agreement
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.
PALO ALTO INVESTORS By: William L. Edwards, President |
PALO ALTO INVESTORS, LLC By: William L. Edwards, President |
William L. Edwards |
PALO ALTO SMALL CAP MASTER FUND, L.P. By: Palo Alto Investors, LLC, General Partner By: Palo Alto Investors, Manager By: William L. Edwards, President |
EXHIBIT
A
AGREEMENT REGARDING JOINT FILING
OF STATEMENT ON SCHEDULE 13D OR
13G
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CUSIP No. 019645506
The
undersigned agree to file jointly with the Securities and Exchange Commission (the "SEC") any and all statements
on Schedule 13D or Schedule 13G (and any amendments or supplements thereto) required under section 13(d) of the
Securities Exchange Act of 1934, as amended, in connection with purchases and sales by the undersigned of the
securities of any issuer until such time as the undersigned file with the SEC a statement terminating this
Agreement Regarding Joint Filing of Statement on Schedule 13D or 13G. For that purpose, the undersigned hereby
constitute and appoint Palo Alto Investors, LLC, a California limited liability company, as their true and lawful
agent and attorney-in-fact, with full power and authority for and on behalf of the undersigned to prepare or
cause to be prepared, sign, file with the SEC and furnish to any other person all certificates, instruments,
agreements and documents necessary to comply with section 13(d) and section 16(a) of the Securities Exchange Act
of 1934, as amended, in connection with said purchases and sales, and to do and perform every act necessary and
proper to be done incident to the exercise of the foregoing power, as fully as the undersigned might or could do
if personally present, until such time as the undersigned file with the SEC a statement terminating this
Agreement Regarding Joint Filing of Statement on Schedule 13D or 13G.
PALO ALTO INVESTORS
By: William L. Edwards, President |
PALO ALTO INVESTORS, LLC By: William L. Edwards, President |
William L. Edwards |
PALO ALTO SMALL CAP MASTER FUND, L.P. By: Palo Alto Investors, LLC, General Partner By: Palo Alto Investors, Manager By: William L. Edwards, President |
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