US3967996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacture of hollow pieces
Assignee: Individual
•
Filing: 1974-10-04
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Granted: 1976-07-06
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Expires: 1994-10-04
Abstract
Abstract A method of manufacturing hollow pieces comprising the steps of forming a blank of single sheets each having a layer of gluing substance applied thereto; placing the blank onto an appropriate mandrel and subjecting it to a preliminary compression so as to impart to the blank a stiffness and to shape it into an unclosed profile as required for subsequent steps. Then the blank ends are brought together so as to define a cavity accommodating an elastic bag. The resulting blank is placed into a mould, and pressure is fed into the elastic bag to perform a final pressing. The above-described method is preferably used to manufacture helicopter rotor blades of glass plastic, which have variable cross-sectional shape over their length and exhibit higher strength and longer service life as compared with metal blades.
Inventors
- 👤 Nikolai Ilich Kamov
- 👤 Nikolai Nikolaevich Priorov
- 👤 Anatoly Fedorovich Kovalev
- 👤 Mark Alexandrovich Kupfer
- 👤 Alexandr Georgievich Satarov
- 👤 Iosif Shulimovich Sherman
- 👤 Anatoly Filippovich Vakulenko
- 👤 Igor Ivanovich Kovyryalkin
- 👤 Stanislav Ivanovich Stetsenko
- 👤 Vladimir Borisovich Golstman
- 👤 Konstantin Nikolaevich Guskov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:16
CPC Classifications
B; B29; B29D; B29D99/00; B29D99/0025; B29D99/0028; B23; B23P; B23P15/00; B23P15/04; B29B; B29B15/00; B29B15/08; B29B15/10; B29B15/12; B29B15/122; B29B15/125; B29C; B29C49/00; B29C49/42; B29C49/44; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/304; B29C70/34; B29C70/342; B29C70/40; B29C70/42; B29C70/44; B29C70/446; B29D24/00; B29D24/002; B29D24/004; B64; B64C; B64C11/00; B64C11/16; B64C11/20; B64C11/24; B64C27/00; B64C27/32; B64C27/46; B64C27/473; B29C43/00; B29C43/02; B29C43/10; B29C43/12; B64C2027/4733; B64C2027/4736; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1044
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
198 words
A method of manufacturing hollow blades and hollow blade spars of aircraft rotors having a variable cross-sectional shape, comprising the steps of: making a composite blank by first assembling each component part thereof from separate flexible flat sheets cut from an adhesive-covered cloth of material which sheets are placed one onto another on a rigid mandrel having an outer surface corresponding with the inner surface of the blade; subjecting each of the component parts assembled of separate sheets and lying on the rigid mandrel to a preliminary compression which consists of applying pressure and heat to the sheets to cause agglutination of the sheets and forming a component part of a blank having an unclosed profile and a rigidity sufficient for subsequent steps; assembling the component parts so as to form a cavity of a closed profile; placing an elastic bag into the cavity; placing the blank assembled of its component parts and with the elastic bag in its cavity into a mold whose inner surface corresponds with the outer surface of the blade; and performing final pressing by supplying pressure into the elastic bag and heating the blank whereby the blade of a specified shape is produced.
Claim 2
Independent Claim
198 words
A method of manufacturing hollow blades and hollow blade spars of aircraft rotors having a variable cross-sectional shape, comprising the steps of: making a composite blank by first assembling each component part thereof from separate flexible flat sheets cut from an adhesive-covered cloth of material which sheets are placed one onto another on a rigid mandrel having an outer surface corresponding with the inner surface of the blade; subjecting each of the component parts assembled of separate sheets and lying on the rigid mandrel to a preliminary compression which consists of applying pressure and heat to the sheets to cause agglutination of the sheets and forming a component part of a blank having an unclosed profile and a rigidity sufficient for subsequent steps; assembling the component parts so as to form a cavity of a closed profile; placing an elastic bag into the cavity; placing the blank assembled of its component parts and with the elastic bag in its cavity into a mold whose inner surface corresponds with the outer surface of the blade; and performing final pressing by supplying pressure into the elastic bag and heating the blank whereby the blade of a specified shape is produced.
Claim 3
Independent Claim
207 words
A method of manufacturing hollow blades and hollow blade spars of aircraft rotors having a variable cross-sectional shape, comprising the steps of: making a composite blank by first assembling each component part thereof from separate flexible flat sheets cut from an adhesive covered cloth of material which sheets are placed one onto another on a rigid mandrel having an outer surface corresponding with the inner surface of the blade; subjecting each of the component parts assembled of separate sheets and lying on the rigid mandrel to a preliminary compression which consists of applying pressure and heat to the sheets to cause agglutination of the sheets and forming a component part of a blank having an unclosed profile and a rigidity sufficient for subsequent steps; assembling the component parts so as to form a number of cavities of a closed profile separated from one another; placing an elastic bag into each of the cavities; placing the blank assembled of its component parts and with the elastic bags in its cavities into a mold whose inner surface corresponds with the outer surface of the blade; and performing final pressing by supplying pressure into the elastic bags and heating the blank whereby the blade of a specified shape is produced.
Claim 4
Independent Claim
207 words
A method of manufacturing hollow blades and hollow blade spars of aircraft rotors having a variable cross-sectional shape, comprising the steps of: making a composite blank by first assembling each component part thereof from separate flexible flat sheets cut from an adhesive covered cloth of material which sheets are placed one onto another on a rigid mandrel having an outer surface corresponding with the inner surface of the blade; subjecting each of the component parts assembled of separate sheets and lying on the rigid mandrel to a preliminary compression which consists of applying pressure and heat to the sheets to cause agglutination of the sheets and forming a component part of a blank having an unclosed profile and a rigidity sufficient for subsequent steps; assembling the component parts so as to form a number of cavities of a closed profile separated from one another; placing an elastic bag into each of the cavities; placing the blank assembled of its component parts and with the elastic bags in its cavities into a mold whose inner surface corresponds with the outer surface of the blade; and performing final pressing by supplying pressure into the elastic bags and heating the blank whereby the blade of a specified shape is produced.
Claim 5
Dependent Claim
30 words
The method according to claim 1, further comprising the step of mounting structural members in each component part assembled from the sheets, the members being fixed during the preliminary compression.
Claim 6
Dependent Claim
30 words
The method according to claim 2, further comprising the step of mounting structural members in each component part assembled from the sheets, the members being fixed during the preliminary compression.
Claim 7
Dependent Claim
35 words
The method according to claim 1, further comprising the step of mounting structural members in each component part when assembling the component parts to form the blank, the members being fixed during the final pressing.
Claim 8
Dependent Claim
35 words
The method according to claim 2, further comprising the step of mounting structural members in each component part when assembling the component parts to form the blank, the members being fixed during the final pressing.
Claim 9
Dependent Claim
19 words
The method according to claim 1, wherein used as the material for the sheets are natural or synthetic fabrics.
Claim 10
Dependent Claim
19 words
The method according to claim 2, wherein used as the material for the sheets are natural or synthetic fabrics.
Claim 11
Dependent Claim
16 words
The method according to claim 1, wherein used as the material for the sheets is foil.
Claim 12
Dependent Claim
16 words
The method according to claim 2, wherein used as the material for the sheets is foil.
Claim 13
Dependent Claim
35 words
The method according to claim 1, further comprising the steps of utilizing the blank cavity as the elastic bag; mounting metal sheets in the cavity; and sealing the joints between the sheets with elastic straps.
Claim 14
Dependent Claim
35 words
The method according to claim 2, further comprising the steps of utilizing the blank cavities as the elastic bags; mounting metal sheets in the cavities; and sealing the joints between the sheets with elastic straps.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-06 | 1980-01-05 | 1980-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-06 | 1984-01-05 | 1984-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-06 | 1988-01-05 | 1988-07-06 | $7700.00 | Window Closed / Lapsed |