Patent US4291566A successfully refreshed from Google Patents.
US4291566A
Expired / Lapsed
US
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Method of and apparatus for forging metal
Assignee: Rolls Royce PLC
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Filing: 1979-09-10
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Granted: 1981-09-29
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Expires: 1999-09-10
Abstract
Abstract A worn titanium blade for a gas turbine engine has metal displaced at its aerofoil tip, so that the aerofoil can be dressed to restore it to length. The titanium is not amenable to cold forging, or to being entirely heated, a forge is therefore provided which has dies which contact only the immediate area containing the metal to be displaced. The dies are heatable so as to heat the said area by conduction and powered so as to apply suitable pressure in a way which brings about isothermal displacement of the titanium.
Inventors
- 👤 Raymond Dinsdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:37
CPC Classifications
B; B23; B23P; B23P6/00; B23P6/002; B21; B21J; B21J5/00; B21J9/00; B21J9/02; B21J9/06; B21J9/08; B21K; B21K29/00; B21K3/00; B21K3/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49318; Y10T29/49718; Y10T29/49748; Y10T29/4975
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
205 words
A method of heating only an extremity of a blade for a gas turbine engine made from a titanium material and then reforming the extremity including the steps of: heating cooperating movable dies of a forge to a forging temperature for the titanium material of the blade; then inserting the extremity of the blade through a close fitting heat shield to a position where only the extremity of the blade to be reformed is between the heated dies with the remainder of the blade being external of the heat shield; applying a first pressure by the heated cooperating dies on the extremity of the blade to clamp the same therebetween and maintaining the clamping pressure of the dies on the extremity of the blade until heat is transferred from the dies only to the extremity of the blade and raises the temperature of the extremity of the blade to the forging temperature of the titanium material; and after forging temperature for the titanium material of the blade has been reached in the extremity of the blade, then increasing pressure of the cooperating dies on the extremity of the blade to a forging pressure sufficient to achieve displacement of material at the extremity of the blade.
Claim 2
Independent Claim
205 words
A method of heating only an extremity of a blade for a gas turbine engine made from a titanium material and then reforming the extremity including the steps of: heating cooperating movable dies of a forge to a forging temperature for the titanium material of the blade; then inserting the extremity of the blade through a close fitting heat shield to a position where only the extremity of the blade to be reformed is between the heated dies with the remainder of the blade being external of the heat shield; applying a first pressure by the heated cooperating dies on the extremity of the blade to clamp the same therebetween and maintaining the clamping pressure of the dies on the extremity of the blade until heat is transferred from the dies only to the extremity of the blade and raises the temperature of the extremity of the blade to the forging temperature of the titanium material; and after forging temperature for the titanium material of the blade has been reached in the extremity of the blade, then increasing pressure of the cooperating dies on the extremity of the blade to a forging pressure sufficient to achieve displacement of material at the extremity of the blade.
Claim 3
Dependent Claim
20 words
A method of hot forging a titanium blade as claimed in claim 1 wherein the forging operation is performed isothermally.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 1 in which clamping pressure of the dies holding the extremity of the blade is maintained for approximately one minute.
Claim 5
Independent Claim
28 words
A method as claimed in claims 1 or 3 in which forging pressure of the dies on the extremity of the blade is maintained for approximately one minute.
Claim 6
Dependent Claim
29 words
A method as claimed in claim 4 in which the forging pressure of the dies on the extremity of the blade is in the order of about ten tons.
Claim 7
Independent Claim
192 words
An apparatus for hot forging only an extremity of a blade for a gas turbine engine made from a titanium material to reform the same, said apparatus comprising: a pair of cooperating dies movable toward one another; heating means for heating said dies to a temperature sufficient to forge the titanium material of the blade; a heat shield including an aperture therein through which the extremity of the blade to be reworked can pass, said aperture closely fitting about the blade with the extremity of the blade being between said dies and the remainder of the blade being external of said heat shield; and means for moving said cooperating dies into engagement with the extremity of the blade to apply an initial clamping pressure about the extremity of the blade to permit only the extremity of the blade to be heated to the forging temperature of the titanium material by heat extracted only from said dies, said means, after the extremity of the blade has been heated, applying a second pressure by the dies to the extremity of the blade sufficient for forging the extremity of the blade to reform the same.
Claim 8
Independent Claim
192 words
An apparatus for hot forging only an extremity of a blade for a gas turbine engine made from a titanium material to reform the same, said apparatus comprising: a pair of cooperating dies movable toward one another; heating means for heating said dies to a temperature sufficient to forge the titanium material of the blade; a heat shield including an aperture therein through which the extremity of the blade to be reworked can pass, said aperture closely fitting about the blade with the extremity of the blade being between said dies and the remainder of the blade being external of said heat shield; and means for moving said cooperating dies into engagement with the extremity of the blade to apply an initial clamping pressure about the extremity of the blade to permit only the extremity of the blade to be heated to the forging temperature of the titanium material by heat extracted only from said dies, said means, after the extremity of the blade has been heated, applying a second pressure by the dies to the extremity of the blade sufficient for forging the extremity of the blade to reform the same.
Claim 9
Dependent Claim
23 words
An apparatus as claimed in claim 6 wherein said heat shield encases said dies and is made of a low thermal conductivity material.
Claim 10
Dependent Claim
15 words
Apparatus as claimed in claim 7 wherein the low thermal conductively material is a ceramic.
Claim 11
Dependent Claim
20 words
Apparatus as claimed in claim 7 wherein the ceramic is in the form of cast blocks arranged adjacent the dies.
Claim 12
Dependent Claim
21 words
Apparatus as claimed in claim 6 comprising a gas burner positioned so as to direct a flame on to said dies.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |