US5595692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of repairing resin impregnated articles
Assignee: RTX Corp
•
Filing: 1994-09-13
•
Granted: 1997-01-21
•
Expires: 2014-09-13
Abstract
Abstract In a method and system for repairing a resin-impregnated article having one or more dry spots or resin-depleted areas, a mold release is used to coat all surfaces of the defective article, except for the resin-depleted areas and a border area surrounding and contiguous to each resin-depleted area. The coated article is then placed within a mold cavity defined by a two-piece mold and corresponding in shape and size to the article. A plurality of shims are interposed in the parting line between the two halves of the mold, creating a first gap within the parting line and a second gap between the surfaces of the article and the walls defining the mold cavity. A gasket is also seated between the two halves of the mold to seal the mold cavity, and a vacuum pump is coupled to the mold cavity to evacuate the cavity to a negative pressure. Heated, substantially degassed resin is then injected into the mold cavity, which flows through the second gap over the coated surfaces of the article and into the resin-depleted areas to impregnate the depleted areas. The shims are then removed and the two halves of the mold are brought into engagement to substantially close the first and second gaps and squeeze excess resin from the mold cavity. The article is then heat treated within the mold cavity to cure the impregnated resin.
Inventors
- 👤 Michael Folsom
- 👤 Paul DiMora
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:09
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/0038; B29C33/0044; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/46; B29C70/48; B29C73/00; B29C73/02; B29C73/025; B29C73/24; B29C73/28
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
105 words
A method of repairing a defective article produced by resin transfer molding having at least one resin-depleted area, comprising the steps of: applying an anti-adherent to an exterior surface of the article excluding the at least one resin-depleted area to substantially prevent infiltration of resin into the anti-adherent applied surface areas; placing the article in a mold cavity defining a shape corresponding to a shape of the defective article; creating a gap between the exterior surface of the defective article and a wall defining the mold cavity; and injecting resin into the gap to impregnate the at least one resin-depleted area with the injected resin.
Claim 2
Independent Claim
105 words
A method of repairing a defective article produced by resin transfer molding having at least one resin-depleted area, comprising the steps of: applying an anti-adherent to an exterior surface of the article excluding the at least one resin-depleted area to substantially prevent infiltration of resin into the anti-adherent applied surface areas; placing the article in a mold cavity defining a shape corresponding to a shape of the defective article; creating a gap between the exterior surface of the defective article and a wall defining the mold cavity; and injecting resin into the gap to impregnate the at least one resin-depleted area with the injected resin.
Claim 3
Dependent Claim
23 words
A method as defined in claim 1, further comprising the steps of heating and pressurizing the resin prior to injection into the gap.
Claim 4
Dependent Claim
27 words
A method as defined in claim 1, further comprising the step of evacuating the mold cavity to a negative pressure prior to injecting resin into the gap.
Claim 5
Dependent Claim
63 words
A method as defined in claim 1, wherein the mold cavity is defined by a mold including first and second mold sections defining a parting line between the two sections, and the step of creating a gap includes creating a gap within the parting line and in turn between the exterior surface of the defective article and the wall defining the mold cavity.
Claim 6
Dependent Claim
32 words
A method as defined in claim 4, wherein the step of creating a gap includes inserting at least one spacing member into the parting line between the first and second mold sections.
Claim 7
Dependent Claim
23 words
A method as defined in claim 1, further comprising the step of substantially closing the gap after injecting the resin into the gap.
Claim 8
Dependent Claim
25 words
A method as defined in claim 6, further comprising the step of thermally curing the article in the mold cavity after substantially closing the gap.
Claim 9
Dependent Claim
41 words
A method as defined in claim 1, wherein the anti-adherent is applied to substantially all of the exterior surface of the article excluding the at least one resin-depleted area and a border area contiguous to a periphery of each resin-depleted area.
Claim 10
Dependent Claim
17 words
A method as defined in claim 1, wherein the anti-adherent is comprised of a mold release agent.
Claim 11
Dependent Claim
34 words
A method as defined in claim 1, further comprising the steps of monitoring resin flow rate, and increasing resin pressure in response to the resin flow rate falling below a first minimum flow rate.
Claim 12
Dependent Claim
52 words
A method as defined in claim 10, wherein the step of injecting resin is terminated in response to at least one of (i) the resin flow rate falling below a second minimum flow rate less than the first minimum flow rate and (ii) the resin pressure reaching a maximum resin pressure value.
Claim 13
Dependent Claim
75 words
A method as defined in claim 10, wherein the step of injecting resin includes applying pressure to a piston and driving the piston within a container holding resin to discharge resin from the container into the gap, and the step of monitoring the resin flow rate includes monitoring a rate of piston travel and increasing the pressure applied to the piston in response to the rate of piston travel falling below a first minimum rate.
Claim 14
Dependent Claim
51 words
A method as defined in claim 12, wherein the step of injecting resin is terminated in response to at least one of (i) the rate of piston travel falling below a second minimum rate less than the first minimum rate and (ii) the resin pressure reaching a maximum resin pressure value.
Claim 15
Dependent Claim
19 words
A method as defined in claim 1, further comprising the step of substantially degassing the resin prior to injection.
Claim 16
Dependent Claim
38 words
A method as defined in claim 14, wherein the degassing step includes connecting a container holding the resin to a vacuum pump and pumping gases from the container, and terminating the pumping after the resin substantially stops bubbling.
References Cited (Backward Citations)
US3814645A
Cited
US4060953B1
Cited
US4060953A
Cited
US4235952A
Cited
US4409270A
Cited
US4528150A
Cited
US4554036A
Cited
US4780162A
Cited
US4632279A
Cited
US4629597A
Cited
US5277730A
Cited
US5435866A
Cited
US5246642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-21 | 2000-07-22 | 2001-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-21 | 2004-07-22 | 2005-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-21 | 2008-07-22 | 2009-01-21 | $7700.00 | Window Closed / Lapsed |