US3719427A - Variable area nozzle for turbines or compressors - Google Patents

Variable area nozzle for turbines or compressors Download PDF

Info

Publication number
US3719427A
US3719427A US00126688A US3719427DA US3719427A US 3719427 A US3719427 A US 3719427A US 00126688 A US00126688 A US 00126688A US 3719427D A US3719427D A US 3719427DA US 3719427 A US3719427 A US 3719427A
Authority
US
United States
Prior art keywords
gears
vanes
rotation
housing
movable vane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00126688A
Inventor
W Davis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Caterpillar Inc
Original Assignee
Caterpillar Tractor Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Application granted granted Critical
Publication of US3719427A publication Critical patent/US3719427A/en
Assigned to CATERPILLAR INC., A CORP. OF DE. reassignment CATERPILLAR INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CATERPILLAR TRACTOR CO., A CORP. OF CALIF.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D17/00—Regulating or controlling by varying flow
    • F01D17/10—Final actuators
    • F01D17/12—Final actuators arranged in stator parts
    • F01D17/14—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits
    • F01D17/16—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of nozzle vanes
    • F01D17/162—Final actuators arranged in stator parts varying effective cross-sectional area of nozzles or guide conduits by means of nozzle vanes for axial flow, i.e. the vanes turning around axes which are essentially perpendicular to the rotor centre line

Definitions

  • the present invention relates to variable area nozzles of the type employed with either a turbine or compressor rotor and more particularly to such a nozzle assembly including intermeshing bevel gears for positively positioning the vanes.
  • Variable area nozzles are known in the priorart, for example, in gas turbine engines to improve efficiency over relatively wide ranges of operating speeds.
  • it is necessary to accurately position each of the movable vanes and to maintain them in the selected position during operation of the turbine or rotor.
  • Such accuracy is difficult to maintain, for example, due to excessive tolerances arising in a drive arrangement for positioning the vanes or to distortion caused by the flow of hot gases through the nozzle.
  • One exemplary prior art arrangement for controlling movable vanes in a variable area nozzle employed a ring gear arranged about the vanes with the ring gear being operable to position the vanes.
  • Such arrangements have not been found completely satisfactory particularly in combination with turbine rotors, for example, because of the particular susceptibility of the ring gear to heat distortion.
  • variable area nozzle assembly including means for accurately positioning movable vanes in the nozzle.
  • FIG. 1 is a fragmentary sectioned view of a variable area nozzle constructed according to the present invention
  • FIG. 2 is a radially sectioned view of the variable area nozzle illustrated in conjunction with a portion of a rotor
  • FIG. 3 is a fragmentary sectioned view of a portion of a variable area nozzle assembly including compensating spring means.
  • variable area nozzle of the present invention is described below within the preferred environment of a gas turbine engine which is partially illustrated in the drawing.
  • a variable area nozzle assembly indicated at 11 is arranged in axial alignment with a bladed turbine rotor 12.
  • An outer annular housing portion 13 and a hub portion 14 of the housing form an annular passage 16 through which gas flows for interaction with the nozzle and turbine rotor.
  • the nozzle assembly includes a plurality of movable vanes 17 journal mounted in the hub 14 by means of bushings such as that indicated at 18 in FIG. 2.
  • An end portion 19 of each vane is similarly mounted in a stepped bore 21 formed by the housing portion 13.
  • a radially inwardly beveled drive gear 22 is secured to the protruding end portion 19 of each vane by means of a nut 23 threadedly engaging the end portion of the vane.
  • Each of the spacer gears 24 is mounted for rotation on a stub shaft 27 by means of a bushing 28.
  • the stub shafts are secured, for example, by press fit into bores 29 formed in the housing portion 13.
  • the spacer gears are also maintained on the shafts 27 by means of threaded nuts 31.
  • a cover 32 provides protection for the gears arranged outwardly of the housing portion 13.
  • a shaft 33 for the operating gear 26 extends outwardly through the cover 32 and may be rotated by means such as a lever (not shown) to operate the drive gears 22 and position the vanes 17.
  • the spacer gears 24 also provide for rotation of each of the vanes in a similar direction.
  • the threaded nuts 23 urge the drive gears 22 radially inwardly to maintain positive engagement between the drive gears 22 and spacer gears 24.
  • the nuts 23 may be adjusted to compensate for wear in the gears, thus maintaining them in positive engagement and tending to minimize or eliminate backlash.
  • the vane 17 and drive gear 22' of FIG. 3 also have a spring 41 which tends to constantly compensate for gear wear and thermal distortion arising during operation of the turbine engine.
  • a spring 41 is arranged in an annular space between the housing portion 13' and each end portion 19' to act radially inwardly on the vanes 17 by means of a bushing 42.
  • the drive gears 22' are urged radially inwardly into positive engagement with the spacer gears. (also see FIG. 1.)
  • Similar springs could also be arranged to urge the spacer gears radially outwardly and thereby constantly compensate for gear wear.
  • a movable vane assembly of the type used in conjunction with a turbine or compressor rotor for interaction with a gas stream comprising a plurality of radially aligned vanes circumferentially arranged within an annular passage formed by a housing, the vanes being supported for rotation about their radial axes to vary the effective crosssection area of the annular passage,
  • compensating means acting axially on at least a portion of the gears for maintaining the gears in positive engagement with each other.
  • vanes are journal mounted in an annular portion and a hub portion of the housing, end portions of the vanes extending through the annular housing portion for connection with the drive gears, the intermediate gears also being journal mounted in the annular housing.
  • the movable vane assembly of claim 3 wherein the operating means comprises an operating gear arranged in meshing relation with two of the drive gears and actuator means coupled with the operating gear.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Turbines (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

A variable area nozzle assembly arranged in an annular housing adjacent a rotor. In order to accurately position movable vanes in the nozzle while compensating for the effects of wear or heat distortion in the nozzle assembly, bevel bears are secured to the vanes and intermediate bevel gears are arranged therebetween with springs axially urging the gears into positive engagement with each other.

Description

United States Patent [191 Davis March 6, 1973 VARIABLE AREA NOZZLE FOR TURBINES OR COMPRESSORS 3,025,036 3/1962 Kumm et al. ..4l5/23 FOREIGN PATENTS OR APPLICATIONS 601,828 5/1948 Great Britain ..415/160 380,701 9/1932 Great Britain ..4l5/163 Primary ExaminerI-lenry F. Raduazo Att0rney-Fryer, Tjensvold, Feix, Phillips & Lempio [57] ABSTRACT A variable area nozzle assembly arranged in an annular housing adjacent a rotor. In order to accurately position movable vanes in the nozzle while compensating for the effects of wear or heat distortion in the nozzle assembly, bevel bears are secured to the vanes [56] References Cited and intermediate bevel gears are arranged therebetween with springs axially urging the gears into UNITED STATES PATENTS positive engagement with each other.
3,327,933 6/1967 Baumann et a1 ..415/150 6 Claims, 3 Drawing Figures l7 2i 7 l 7 VARIABLE AREA NOZZLE FOR TURBINES OR COMPRESSORS The present invention relates to variable area nozzles of the type employed with either a turbine or compressor rotor and more particularly to such a nozzle assembly including intermeshing bevel gears for positively positioning the vanes.
Variable area nozzles are known in the priorart, for example, in gas turbine engines to improve efficiency over relatively wide ranges of operating speeds. In such nozzle assemblies, it is necessary to accurately position each of the movable vanes and to maintain them in the selected position during operation of the turbine or rotor. Such accuracy is difficult to maintain, for example, due to excessive tolerances arising in a drive arrangement for positioning the vanes or to distortion caused by the flow of hot gases through the nozzle.
One exemplary prior art arrangement for controlling movable vanes in a variable area nozzle employed a ring gear arranged about the vanes with the ring gear being operable to position the vanes. Such arrangements have not been found completely satisfactory particularly in combination with turbine rotors, for example, because of the particular susceptibility of the ring gear to heat distortion.
Accordingly, it is an object of the present invention to provide a variable area nozzle assembly including means for accurately positioning movable vanes in the nozzle.
It is a further object of the invention to provide such a variable area nozzle wherein the positions of the movable vanes are controlled by bevel gears with compensating means for maintaining the gears in positive engagement and thus reducing or eliminating the problem of backlash within the meshing arrangement of gears.
Other objects and advantages of the present invention are made apparent in the following description having reference to the accompanying drawing.
In the drawing:
FIG. 1 is a fragmentary sectioned view of a variable area nozzle constructed according to the present invention;
FIG. 2 is a radially sectioned view of the variable area nozzle illustrated in conjunction with a portion of a rotor; and
FIG. 3 is a fragmentary sectioned view of a portion of a variable area nozzle assembly including compensating spring means.
The variable area nozzle of the present invention is described below within the preferred environment of a gas turbine engine which is partially illustrated in the drawing. Referring to FIG. 1 and particularly to FIG. 2, a variable area nozzle assembly indicated at 11 is arranged in axial alignment with a bladed turbine rotor 12. An outer annular housing portion 13 and a hub portion 14 of the housing form an annular passage 16 through which gas flows for interaction with the nozzle and turbine rotor.
The nozzle assembly includes a plurality of movable vanes 17 journal mounted in the hub 14 by means of bushings such as that indicated at 18 in FIG. 2. An end portion 19 of each vane is similarly mounted in a stepped bore 21 formed by the housing portion 13. A radially inwardly beveled drive gear 22 is secured to the protruding end portion 19 of each vane by means of a nut 23 threadedly engaging the end portion of the vane.
single operating gear 26 is arranged in meshing relation with one pair of the drive gears. Each of the spacer gears 24 is mounted for rotation on a stub shaft 27 by means of a bushing 28. The stub shafts are secured, for example, by press fit into bores 29 formed in the housing portion 13. The spacer gears are also maintained on the shafts 27 by means of threaded nuts 31.
A cover 32 provides protection for the gears arranged outwardly of the housing portion 13. A shaft 33 for the operating gear 26 extends outwardly through the cover 32 and may be rotated by means such as a lever (not shown) to operate the drive gears 22 and position the vanes 17. The spacer gears 24 also provide for rotation of each of the vanes in a similar direction.
As may be best seen, the threaded nuts 23 urge the drive gears 22 radially inwardly to maintain positive engagement between the drive gears 22 and spacer gears 24. The nuts 23 may be adjusted to compensate for wear in the gears, thus maintaining them in positive engagement and tending to minimize or eliminate backlash.
The vane 17 and drive gear 22' of FIG. 3 also have a spring 41 which tends to constantly compensate for gear wear and thermal distortion arising during operation of the turbine engine. Such a spring 41 is arranged in an annular space between the housing portion 13' and each end portion 19' to act radially inwardly on the vanes 17 by means of a bushing 42. Thus, the drive gears 22' are urged radially inwardly into positive engagement with the spacer gears. (also see FIG. 1.)
Similar springs could also be arranged to urge the spacer gears radially outwardly and thereby constantly compensate for gear wear.
What is claimed is:
1. A movable vane assembly of the type used in conjunction with a turbine or compressor rotor for interaction with a gas stream, comprising a plurality of radially aligned vanes circumferentially arranged within an annular passage formed by a housing, the vanes being supported for rotation about their radial axes to vary the effective crosssection area of the annular passage,
a plurality of rotatable bevel gears circumferentially arranged upon the housing, alternate gears being coupled for driving the respective vanes in rotation, the intermediate gears occupying spaces between the drive gears and providing for rotation of the drive gears and vanes in a common direction of rotation,
operating means effectively coupled with the gears for selectively controlling the rotational positions of the vanes, and
compensating means acting axially on at least a portion of the gears for maintaining the gears in positive engagement with each other.
2. The movable vane assembly of claim 1 wherein the vanes are journal mounted in an annular portion and a hub portion of the housing, end portions of the vanes extending through the annular housing portion for connection with the drive gears, the intermediate gears also being journal mounted in the annular housing.
3. The movable vane assembly of claim 2 wherein the drive gears have beveled gear teeth and the intermediate gears have mating beveled gear teeth, the compensating means comprising springs arranged for interaction between the annular housing portion and the end portions of the vanes.
4. The movable vane assembly of claim 3 wherein the operating means comprises an operating gear arranged in meshing relation with two of the drive gears and actuator means coupled with the operating gear.
5. The movable vane assembly of claim 1 wherein the compensating means are arranged for axial interaction

Claims (6)

1. A movable vane assembly of the type used in conjunction with a turbine or compressor rotor for interaction with a gas stream, comprising a plurality of radially aligned vanes circumferentially arranged within an annular passage formed by a housing, the vanes being supported for rotation about their radial axes to vary the effective cross-section area of the annular passage, a plurality of rotatable bevel gears circumferentially arranged upon the housing, alternate gears being coupled for driving the respective vanes in rotation, the intermediate gears occupying spaces between the drive gears and providing for rotation of the drive gears and vanes in a common direction of rotation, operating means effectively coupled with the gears for selectively controlling the rotational positions of the vanes, and compensating means acting axially on at least a portion of the gears for maintaining the gears in positive engagement with each other.
1. A movable vane assembly of the type used in conjunction with a turbine or compressor rotor for interaction with a gas stream, comprising a plurality of radially aligned vanes circumferentially arranged within an annular passage formed by a housing, the vanes being supported for rotation about their radial axes to vary the effective cross-section area of the annular passage, a plurality of rotatable bevel gears circumferentially arranged upon the housing, alternate gears being coupled for driving the respective vanes in rotation, the intermediate gears occupying spaces between the drive gears and providing for rotation of the drive gears and vanes in a common direction of rotation, operating means effectively coupled with the gears for selectively controlling the rotational positions of the vanes, and compensating means acting axially on at least a portion of the gears for maintaining the gears in positive engagement with each other.
2. The movable vane assembly of claim 1 wherein the vanes are journal mounted in an annular portion and a hub portion of the housing, end portions of the vanes extending through the annular housing portion for connection with the drive gears, the intermediate gears also being journal mounted in the annular housing.
3. The movable vane assembly of claim 2 wherein the drive gears have beveled gear teeth and the intermediate gears have mating beveled gear teeth, the compensating means comprising springs arranged for interaction between the annular housing portion and the end portions of the vanes.
4. The movable vane assembly of claim 3 wherein the operating means comprises an operating gear arranged in meshing relation with two of the drive gears and actuator means coupled with the operating gear.
5. The movable vane assembly of claim 1 wherein the compensating means are arranged for axial interaction with alternate ones of the gears, the compensating means being effectIve to urge the alternate gears against the remaining gears and thus provide for positive engagement between all of the plurality of gears.
US00126688A 1971-03-22 1971-03-22 Variable area nozzle for turbines or compressors Expired - Lifetime US3719427A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12668871A 1971-03-22 1971-03-22

Publications (1)

Publication Number Publication Date
US3719427A true US3719427A (en) 1973-03-06

Family

ID=22426193

Family Applications (1)

Application Number Title Priority Date Filing Date
US00126688A Expired - Lifetime US3719427A (en) 1971-03-22 1971-03-22 Variable area nozzle for turbines or compressors

Country Status (1)

Country Link
US (1) US3719427A (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804550A (en) * 1972-01-12 1974-04-16 Lucas Aerospace Ltd Control vane arrangement for gas turbine
US3816021A (en) * 1971-12-11 1974-06-11 Lucas Aerospace Ltd Control vane arrangement for a gas turbine engine
US3857649A (en) * 1973-08-09 1974-12-31 Westinghouse Electric Corp Inlet vane structure for turbines
EP0289697A1 (en) * 1987-04-03 1988-11-09 MAN Gutehoffnungshütte Aktiengesellschaft Actuator for the variable guide vanes of an axial turbo machine
US6779971B2 (en) * 2000-10-12 2004-08-24 Holset Engineering Company, Limited Turbine
US6821084B2 (en) 2002-12-11 2004-11-23 General Electric Company Torque tube bearing assembly
US20050232757A1 (en) * 2003-05-27 2005-10-20 General Electric Company Wear resistant variable stator vane assemblies
US20060029494A1 (en) * 2003-05-27 2006-02-09 General Electric Company High temperature ceramic lubricant
US20060245676A1 (en) * 2005-04-28 2006-11-02 General Electric Company High temperature rod end bearings
US20070160463A1 (en) * 2005-08-26 2007-07-12 Ingo Jahns Gap control arrangement for a gas turbine
US20100202873A1 (en) * 2009-02-06 2010-08-12 General Electric Company Ceramic Matrix Composite Turbine Engine
US8123150B2 (en) 2010-03-30 2012-02-28 General Electric Company Variable area fuel nozzle
US8382436B2 (en) 2009-01-06 2013-02-26 General Electric Company Non-integral turbine blade platforms and systems
US20130089417A1 (en) * 2011-10-07 2013-04-11 David J. Wiebe Wear prevention system for securing compressor airfoils within a turbine engine
US8668445B2 (en) 2010-10-15 2014-03-11 General Electric Company Variable turbine nozzle system
BE1030541B1 (en) * 2022-05-19 2023-12-19 Safran Aero Boosters DEFORMABLE COUPLING FOR VARIABLE PITCH BLADE

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB380701A (en) * 1931-02-06 1932-09-22 Albert Huguenin Improved distributor for reversible hydraulic turbines
GB601828A (en) * 1945-10-04 1948-05-13 B F Sturtevant Co Improvements relating to control vanes for fans
US3025036A (en) * 1960-01-06 1962-03-13 Curtiss Wright Corp Gas turbine speed control
US3327933A (en) * 1964-08-07 1967-06-27 Bbc Brown Boveri & Cie Apparatus for regulating a turbocompressor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB380701A (en) * 1931-02-06 1932-09-22 Albert Huguenin Improved distributor for reversible hydraulic turbines
GB601828A (en) * 1945-10-04 1948-05-13 B F Sturtevant Co Improvements relating to control vanes for fans
US3025036A (en) * 1960-01-06 1962-03-13 Curtiss Wright Corp Gas turbine speed control
US3327933A (en) * 1964-08-07 1967-06-27 Bbc Brown Boveri & Cie Apparatus for regulating a turbocompressor

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3816021A (en) * 1971-12-11 1974-06-11 Lucas Aerospace Ltd Control vane arrangement for a gas turbine engine
US3804550A (en) * 1972-01-12 1974-04-16 Lucas Aerospace Ltd Control vane arrangement for gas turbine
US3857649A (en) * 1973-08-09 1974-12-31 Westinghouse Electric Corp Inlet vane structure for turbines
EP0289697A1 (en) * 1987-04-03 1988-11-09 MAN Gutehoffnungshütte Aktiengesellschaft Actuator for the variable guide vanes of an axial turbo machine
US4836746A (en) * 1987-04-03 1989-06-06 Man Gutehoffnungshuette Gmbh Axial flow engine guide vane adjusting device
US6779971B2 (en) * 2000-10-12 2004-08-24 Holset Engineering Company, Limited Turbine
US6821084B2 (en) 2002-12-11 2004-11-23 General Electric Company Torque tube bearing assembly
US7220098B2 (en) 2003-05-27 2007-05-22 General Electric Company Wear resistant variable stator vane assemblies
US20050232757A1 (en) * 2003-05-27 2005-10-20 General Electric Company Wear resistant variable stator vane assemblies
US20060029494A1 (en) * 2003-05-27 2006-02-09 General Electric Company High temperature ceramic lubricant
US20060245676A1 (en) * 2005-04-28 2006-11-02 General Electric Company High temperature rod end bearings
US7543992B2 (en) 2005-04-28 2009-06-09 General Electric Company High temperature rod end bearings
US20070160463A1 (en) * 2005-08-26 2007-07-12 Ingo Jahns Gap control arrangement for a gas turbine
US8382436B2 (en) 2009-01-06 2013-02-26 General Electric Company Non-integral turbine blade platforms and systems
US20100202873A1 (en) * 2009-02-06 2010-08-12 General Electric Company Ceramic Matrix Composite Turbine Engine
US8262345B2 (en) 2009-02-06 2012-09-11 General Electric Company Ceramic matrix composite turbine engine
US8123150B2 (en) 2010-03-30 2012-02-28 General Electric Company Variable area fuel nozzle
US8668445B2 (en) 2010-10-15 2014-03-11 General Electric Company Variable turbine nozzle system
US20130089417A1 (en) * 2011-10-07 2013-04-11 David J. Wiebe Wear prevention system for securing compressor airfoils within a turbine engine
US8920116B2 (en) * 2011-10-07 2014-12-30 Siemens Energy, Inc. Wear prevention system for securing compressor airfoils within a turbine engine
BE1030541B1 (en) * 2022-05-19 2023-12-19 Safran Aero Boosters DEFORMABLE COUPLING FOR VARIABLE PITCH BLADE

Similar Documents

Publication Publication Date Title
US3719427A (en) Variable area nozzle for turbines or compressors
US2860827A (en) Turbosupercharger
US3943703A (en) Cooling passages through resilient clamping members in a gas turbine power plant
US3647311A (en) Turbine interstage seal assembly
US2651492A (en) Turbine
US10450877B2 (en) Guide means for a gas turbine and gas turbine having such a guide means
JP4474088B2 (en) Method for reducing seal tooth wear, honeycomb seal and gas turbine engine
EP0202188B1 (en) Two stage turbine rotor assembly
US4218189A (en) Sealing means for bladed rotor for a gas turbine engine
US3818696A (en) Regenerative air-cooled gas turbine engine
US4901523A (en) Rotor for gas turbine engine
US6575704B1 (en) Turbomachine and sealing element for a rotor thereof
JPH01159499A (en) Split shroud type compressor
JP2013519836A (en) Drive device for rotating adjustable blades of turbomachine
US20180223868A1 (en) Turbine Engine Compressor with Variable-Pitch Vanes
CN105745415A (en) Variable displacement supercharger
US2741454A (en) Elastic fluid machine
US10450884B2 (en) Impeller having a radial seal for a turbine engine turbine
US8561997B2 (en) Adverse pressure gradient seal mechanism
JP3091179B2 (en) Positioning drive mechanism and backlash adjustment mechanism
US20180306048A1 (en) Sealing ring element for a turbine comprising an inclined cavity in an abradable material
US3765795A (en) Compositely formed rotors and their manufacture
US2788951A (en) Cooling of turbine rotors
US5435693A (en) Pin and roller attachment system for ceramic blades
GB2192943A (en) A variable pitch blade assembly

Legal Events

Date Code Title Description
AS Assignment

Owner name: CATERPILLAR INC., A CORP. OF DE.,ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515

Owner name: CATERPILLAR INC., 100 N.E. ADAMS STREET, PEORIA, I

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515