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US 4,358,471 AGranted
Control apparatus
AssigneeTRW Inc.
InventorsThomas Derkacs, Charles W. Fetheroff, Istvan M. Matay, Istvan J. Toth
Life of this patent
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AssigneeTRW Inc.
InventorsThomas Derkacs, Charles W. Fetheroff, Istvan M. Matay, Istvan J. Toth
Estimating the term…
Although the method and apparatus of the present invention can be utilized to apply either a uniform or a nonuniform covering of material over many different workpieces, the apparatus (20) is advantageously utilized to apply a thermal barrier covering (64) to an airfoil (22) which is used in a turbine engine. The airfoil is held by a gripper assembly (86) while a spray gun (24) is effective to apply the covering over the airfoil. When a portion of the covering has been applied, a sensor (28) is utilized to detect the thickness of the covering. A control apparatus (32) compares the thickness of the covering of material which has been applied with the desired thickness and is subsequently effective to regulate the operation of the spray gun to adaptively apply a covering of a desired thickness with an accuracy of at least plus or minus 0.0015 inches (1.5 mils) despite unanticipated process variations.
A method of forming an airfoil, said method comprising the steps of providing a base having a configuration which is different than the configuration of the airfoil, applying material to the base to form the airfoil, said step of applying material to the base to form the airfoil including the steps of operating a spray means to direct a flow of material toward the base to form on the base a body of sprayed material extending at least part way around the base and having an exterior surface area with a configuration corresponding to the configuration of at least a portion of the airfoil, and removing the base from the body of sprayed material to provide an airfoil having a cavity with a configuration corresponding to the configuration of the base.
A method of applying a covering over at least a portion of a workpiece, said method comprising the steps of holding the workpiece with a gripper means, providing a spray means which is selectively operable to direct a flow of material having either a first composition or a second composition toward the workpiece while it is held by said gripper means, operating the spray means to direct a flow of material having the first composition toward the workpiece to form over at least a portion of the workpiece an initial covering having a thickness which is less than a first predetermined thickness and is formed of material having the first composition while the workpiece is held by said gripper means, detecting the thickness of the initial covering while holding the workpiece with said gripper means, operating the spray means to increase the thickness of the initial covering of material having the first composition to the first predetermined thickness while holding the workpiece with the gripper means, operating the spray means to direct a flow of material having the second composition toward the workpiece to form over at least a portion of the initial covering a second covering having a thickness which is less than a second predetermined thickness and is formed of material having the second composition while the workpiece is held by the gripper means, detecting the thickness of the second covering while holding the workpiece with the gripper means, and operating the spray means to increase the thickness of the second covering of material having the second composition to the second predetermined thickness while holding two workpiece with the gripper means.
A method of applying a covering of a predetermined thickness to at least a portion of a workpiece, said method including the steps of engaging the workpiece with a gripper assembly, applying material to the workpiece by operating a spray means to direct a flow of the material toward the workpiece while it is held by the gripper assembly, said step of operating a spray means includes the steps of supplying material in a powdered form to the spray means, heating the material and directing a flow of the heated material toward the workpiece, effecting relative movement between the spray means and the workpiece during said step of applying material to the workpiece, after applying material to the workpiece to form an initial covering of a thickness which is less than the predetermined thickness, interrupting the application of material to the workpiece, determining the thickness of the initial covering without engaging the initial covering with a solid object, said step of determining the thickness of the initial covering including the step of directing radiant energy against the initial covering while the workpiece is held by the gripper assembly, and increasing the thickness of the initial covering to the predetermined thickness after having determined the thickness of the initial covering by again operating the spray means to direct a flow of the material toward the workpiece while holding the workpiece with the gripper assembly.
A method of applying a covering over at least a portion of a workpiece, said method comprising the steps of holding the workpiece with a gripper means, providing a spray means which is selectively operable to direct a flow of material having either a first composition, a second composition, or a mixture of the first and second compositions toward the workpiece while it is held by said gripper means, operating the spray means to direct a flow of material having the first composition toward the workpiece to form over at least a portion of the workpiece an initial covering formed of material having the first composition while the workpiece is held by said gripper means, operating the spray means to direct a flow of material having a composition which is a mixture of the first and second materials toward the workpiece to form over at least a portion of the initial covering a transition covering formed of material which is a mixture of the first and second compositions while the workpiece is held by said gripper means, and operating the spray means to direct a flow of material having the second composition toward the workpiece to form over at least a portion of the transition covering a third covering formed of material having the second composition while the workpiece is held by the gripper means, said step of holding the workpiece with the gripper means includes the step of continuously holding the workpiece with the gripper means from a time immediately prior to initiation of operation of the spray means to apply the initial covering at least until completion of application of the third covering.
A method of applying a covering over at least a portion of a workpiece with a spray assembly while the workpiece is held by a gripper, said method comprising the steps of gripping the workpiece with the gripper, supporting the gripper for rotational movement about an axis extending through the workpiece while it is held by the gripper and for pivotal movement in any direction relative to the spray assembly about a pivot point disposed on the axis to enable the orientation of the workpiece relative to the spray assembly to be varied, rotating the gripper and workpiece about the axis which extends through the workpiece to vary the orientation of the workpiece relative to the spray assembly, and pivoting the workpiece about the pivot point to further vary the orientation of the workpiece relative to the spray assembly.
A method of applying a covering over at least a portion of a workpiece with a spray assembly while the workpiece is held by a gripper, said method comprising the steps of gripping the workpiece with the gripper, applying a first layer of the covering to the workpiece in longitudinally extending strips by effecting relative movement between the spray assembly and gripper while operating the spray assembly to direct a flow of material toward the workpiece, detecting the thickness of the first layer of the covering, comparing the thickness of the first layer of the covering to a desired thickness, and applying a second layer of the covering to the workpiece in longitudinally extending strips which overlie the strips of the first layer of the covering and have longitudinal central axes which are offset from the longitudinal central axes of the first layer of the covering by effecting relative movement between the spray assembly and gripper while operating the spray assembly to direct a flow of material toward the workpiece, said step of applying a second layer of the covering to the workpiece being continued until the covering has the desired thickness.
A method of applying a covering of material to at least a portion of an airfoil, said method comprising the steps of gripping one end portion of the airfoil with a gripper, supplying material in a powdered form to a spray assembly, directing a flow of the powdered material from the spray assembly toward the airfoil, rotating the gripper and airfoil relative to the spray assembly about a first axis which extends generally parallel to the path of flow of material from the spray assembly to change the orientation of the airfoil relative to the spray assembly, rotating the gripper and airfoil relative to the spray assembly about a second axis which extends transversely to the first axis to change the orientation of the airfoil relative to the spray assembly, and rotating the gripper and airfoil relative to the spray assembly about a third axis which extends transversely to the first and second axes to change the orientation of the airfoil relative to the spray assembly.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, determining the thickness of the initial covering, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering, at least one of the steps of applying an initial covering and increasing the thickness of the covering including the steps of effecting relative movement between the spray means and the workpiece along each of three transversely extending axes and effecting rotational movement between the spray means and the workpiece about each of three transversely extending axes to thereby vary the spatial relationship between the spray means and the workpiece.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, determining the thickness of the initial covering, said step of determining the thickness of the initial covering includes the steps of providing a source of light, directing light from the light source against a surface area of the initial covering with a lens, reflecting light from the surface area to a photosensor, decreasing the amount of light reflected back to the photosensor by effecting relative movement between the lens and the surface area of the initial covering in one direction, subsequently increasing the amount of light reflected back to the photosensor by continuing to effect relative movement between the lens and the surface area of the initial covering in the one direction and detecting when the lens is spaced apart from the surface area of the initial covering by a predetermined distance by detecting when the amount of light reflected back to the photosensor stops decreasing and starts increasing as the distance between the lens and the surface area of the initial covering is changed in the one direction, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, said step of applying an initial covering to the workpiece includes the steps of applying a plurality of layers of material to the workpiece to form the initial covering, said steps of applying a plurality of layers of material to the workpiece including the steps of applying one of the layers in strips and applying the next succeeding layer in strips having longitudinal axes which are offset from longitudinal axes of the strips of the one layer, determining the thickness of the initial covering, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of a desired thickness to at least a portion of a workpiece having an internal passage, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, said step of operating a spray means including the steps of supplying material in a powdered form to said spray means, heating the material, and directing a flow of the heated material toward the workpiece, inducing a flow of fluid through the internal passage while directing the flow of heated material toward the workpiece, determining the thickness of the initial covering, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, said step of applying an initial covering to the workpiece includes the step of effecting relative movement between the workpiece and spray means and varying the speed of relative movement between the workpiece and spray means to vary the amount of material which is applied over a surface area of the workpiece, determining the thickness of the initial covering, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, determining the thickness of the initial covering, comparing the thickness of the initial covering with desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering, at least one of the steps of applying an initial covering and increasing the thickness of the covering including the step of effecting pivotal movement of the workpiece relative to the spray means in any direction about a pivot point to vary the orientation of the workpiece relative to the spray means.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, said step of applying an initial covering to the workpiece includes the step of applying a plurality of longitudinally extending strips to the workpiece with the strips in an overlapping relationship, determining the thickness of the initial covering, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, interrupting operation of the spray means when the thickness of the covering applied to the airfoil is less than the desired thickness, determining the thickness of the covering on the airfoil with an accuracy which is within less than 0.0005 of the actual thickness of the covering, and resuming operating the spray means to increase the thickness of the covering, said step of determining the thickness of the covering on the airfoil includes the steps of providing a light source, directing light from the source of light against a surface area of the airfoil with a lens before applying material to the airfoil with the spray means, increasing the amount of light reflected back to the light source by changing the distance between the lens and the surface area of the airfoil in a first direction from a first distance to a predetermined distance, subsequently decreasing the amount of light reflected back to the light source by changing the distance between the lens and the surface of the airfoil in the first direction from the predetermined distance to a second distance, detecting when the lens is spaced apart from the surface area of the airfoil by the predetermined distance by detecting when the amount of light reflected back to the light source stops increasing and starts decreasing, and determining the position of the airfoil relative to a reference location when the lens is spaced apart from the airfoil by the predetermined distance, after at least partially performing said step of operating the spray means to apply a covering of a desired thickness to the airfoil performing the steps of directing light from the source of light against a surface area of the covering with the lens, increasing the amount of light reflected back to the light source by changing the distance between the lens and the surface area of the covering in the first direction from a first distance to a predetermined distance, subsequently decreasing the amount of light relfected back to the light source by changing the distance between the lens and the surface area of the covering in the first direction from the predetermined distance to a distance which is different than the predetermined distance, detecting when the lens is spaced apart from the surface area of the covering by the predetermined distance by detecting when the amount of light reflected back to the light source stops increasing and starts decreasing, and determining the position of the airfoil relative to the reference location when the lens is spaced apart from the surface area of the covering by the predetermined distance.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, engaging the airfoil with a gripper assembly prior to performing said step of operating a spray means, supporting the airfoil at first location with the gripper assembly during performance of said step of operating a spray means, moving the airfoil to a second location while supporting the airfoil with the gripper assembly, measuring the thickness of the covering applied to the airfoil by the spray means while supporting the airfoil at the second location with the gripper assembly, moving the airfoil back to the first location while supporting the airfoil with the gripper assembly, and resuming the application of material to the airfoil while it is supported at the first location by the gripper assembly.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, determining the thickness of the covering of material applied to the airfoil, said step of determining the thickness of the covering on the airfoil including the steps of locating the airfoil at a measuring station with a surface area on the airfoil at a predetermined position before applying material to the airfoil with said spray means, and, after applying at least a portion of the covering to the airfoil, locating the airfoil at the measuring station with a surface area on the covering at the predetermined position.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, effecting relative movement between the airfoil and the spray means to effect the application of the covering to the airfoil in a plurality of longitudinally extending strips.
A method of applying a covering of material over at least a portion of an airfoil having an internal passage, said method comprising the steps of providing an airfoil operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, and inducing a flow of fluid through the internal passage while directing the heated material toward the airfoil to thereby cool the airfoil.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, and utilizing electrical energy from a source of electrical energy to detect the thickness of the covering applied to the airfoil without engaging the covering with a solid object.
A method as set forth in claim 169 wherein said step of utilizing electrical energy to detect the thickness of the covering includes the step of detecting the thickness of the covering on the airfoil with an accuracy which is within less than 0.0005 of the actual thickness of the covering.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, effecting relative movement between the spray means and the airfoil along each of three transversely extending axes, and effecting rotational movement between the spray means and the airfoil about each of three transversely extending axes to thereby vary the spatial relationship between the spray means and the airfoil.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, and effecting pivotal movement of the airfoil relative to the spray means in any direction about a pivot point to vary the orientation of the airfoil relative to the spray means.
A method of applying a covering of material over at least a portion of an airfoil, said method comprising the steps of providing an airfoil, operating a spray means to apply to the airfoil a covering having a thickness which differs from a desired thickness by less than 0.0015 of an inch, said step of operating a spray means includes the steps of supplying material in powdered form to the spray means, heating the material, and directing a flow of the heated material toward the airfoil, and effecting relative movement between the airfoil and the spray means to effect the application of the covering to the airfoil by sequentially applying a plurality of layers of material to the airfoil, said step of applying a plurality of layers of material to the airfoil includes the steps of sequentially spraying a plurality of longitudinally extending strips of the material onto the airfoil to form one of the layers and sequentially spraying onto the one layer a plurality of longitudinally extending strips of material to form the next succeeding layer.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, determining the thickness of the initial covering, wherein said step of determining the thickness of the intial covering includes the steps of providing a source of light, directing light from the light source against the initial covering with a lens, reflecting light from the initial covering back to the light source, increasing the amount of light reflected back to the light source by varying the distance between the lens and the initial covering in a first direction, subsequently decreasing the amount of light reflected back to the light source by continuing varying the distance between the lens and the initial covering in the first direction, and detecting when the lens is spaced apart from the initial covering by a predetermined distance by detecting when the amount of light reflected back to the light source stops increasing and starts decreasing, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method of applying a covering of a desired thickness to at least a portion of a workpiece, said method comprising the steps of applying to the workpiece an initial covering having a thickness which is less than the desired thickness by operating a spray means to direct a flow of material toward the workpiece, determining the thickness of the initial covering, said step of determining the thickness of the initial covering includes the steps of providing a source of light, directing light from the light source against a surface area of the initial covering with a lens, reflecting light from the surface area to a photosensor, decreasing the amount of light reflected back to the photosensor by effecting relative movement between the lens and the surface area of the initial covering in one direction, subsequently increasing the amount of light reflected back to the photosensor by continuing to effect relative movement between the lens and the surface area of the intial covering in the one direction and detecting when the lens is spaced apart from the surface area of the initial covering by a predetermined distance by detecting when the amount of light reflected back to the photosensor stops decreasing and starts increasing as the distance between the lens and the surface area of the initial covering is changed in the one direction, comparing the thickness of the initial covering with the desired covering thickness to determine the difference between thickness of the initial covering and the desired covering thickness, and increasing the thickness of the covering to the desired thickness by operating the spray means to direct a flow of material toward the initial covering.
A method comprising the steps of providing a workpiece, gripping the workpiece with a gripper assembly, operating a spray means to apply a covering over at least a portion of the workpiece while the workpiece is gripped by the gripper assembly, effecting relative movement between the spray means and the workpiece by moving the gripper assembly relative to the spray means while gripping the workpiece with the gripper assembly, measuring the thickness of the covering applied to the workpiece by the spray means while gripping the workpiece with the gripper assembly, resuming the application of material to the workpiece by operating the spray means after having performed said step of measuring the thickness of the covering and while gripping the workpiece with the gripper assembly, and continuously maintaining a grip on the workpiece with the gripper assembly from the time at which said step of operating a spray means is initiated at least until completion of said step of resuming the application of material to the workpiece.
Dependencies are inferred from the claim text.