DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments with respect to claims 1-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
The Applicant’s arguments on pages 9-14 are drawn to the amendments to independent claims 1 & 20, and will be discussed in the 35 U.S.C. 103 Rejections section, below. The Applicant argues that the four arts of record do not teach these amended claim elements; however, the prior art of Blanchard was found to teach embodiments meeting the amended elements for claims 1-20.
Amendments to claims 1, 10 & 20 are acknowledged.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or non-obviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-9 & 14-19 are rejected under 35 U.S.C. 103 as being unpatentable over Stadtlander (US20080263844A1, of record) in view of Blanchard (US20100276065A1, of record) and Grosskrueger (US6656299B1, of record). Claim elements are presented in italics.
1. A sandwich structure, comprising: a first sheet comprising an outer surface; a second sheet opposite the first sheet; a core interposed between and coupled to the first sheet and the second sheet; a cavity formed in the first sheet and the core; and a structural reinforcement coupled to the outer surface of the first sheet over and in the cavity, the structural reinforcement comprising: a patch comprising a ply; and a cured potting compound packed into the cavity and further located on the outer surface of the first sheet; wherein: the cured potting compound is interposed between and bonded to the patch and the cavity to repair an abnormality in the core; and the cured potting compound is interposed between bonded to the patch and the outer surface of the first sheet to adhere the patch to the first sheet; the cured potting compound packed into the cavity is materially continuous with the cured potting compound located on the outer surface of the first sheet, such that the cured potting compound forms a single cured mass extending from within the cavity onto the outer surface of the first sheet; and the patch is coupled to the outer surface of the first sheet by the same cured potting compound forming the single cured mass.
With respect to claim 1, the prior art of Stadtlander teaches a sandwich structure (Fig. 6), comprising: a first sheet comprising an outer surface (Fig. 6, item 50; [0030]); a second sheet opposite the first sheet (Fig. 6, item 32); a core (Fig. 6, items 36) interposed between and coupled to the first sheet and the second sheet [0021]; a cavity (Fig. 3, item 28b) formed in the first sheet and the core [0018]; and a structural reinforcement coupled to the outer surface of the first sheet over and in the cavity, the structural reinforcement comprising: a patch comprising a first ply (Fig. 6, item 50) and a second ply (Fig. 6, item 52; [0030]).
Stadtlander teaches an embodiment wherein the cavity can be packed with a potting compound (Fig. 11, item 147) surrounding a stiffener component (Fig. 11, item 142; [0045-0046]); wherein adhesive 146 can be the same as the potting compound 147 [0045], and the potting compound will fill all unoccupied spaces within the cavity [0045].
Stadtlander teaches an adhesive (Fig. 6, item 54) is applied over the filled cavity and across the first layer to provide bonding with the first and second plies (Fig. 6, items 50, 52) of the patch [0030-0031]. Stadtlander teaches the adhesive 54 may be an epoxy film adhesive [0030].
Stadtlander, however, teaches a curing step for the cavity adhesive [0027], and then any potting compound or stiffener extending out of the cavity past the first layer (as shown in Fig. 11) can be ground down to match the first layer before a patch is applied [0029, 0046], before the patch and its adhesive are applied [0030].
Stadtlander is silent on the cured potting compound packed into the cavity is materially continuous with the cured potting compound located on the outer surface of the first sheet, such that the cured potting compound forms a single cured mass extending from within the cavity onto the outer surface of the first sheet.
However, the prior art of Blanchard teaches an adhesive (Fig. 19, item 336; [0114]) to fill a repair cavity and bond a patch (Figs. 18 & 19, item 314; [0113]) onto a first sheet (surface) layer, wherein the adhesive forms a single cured mass. Blanchard teaches the cavity repair for a top sheet and core layers of an airplane skin panel application (Fig. 19, item 312; [0110]).
Blanchard teaches the cavity repair comprises filling the cavity with an adhesive and applying the adhesive continuously onto the first sheet layer (Fig. 19, item 328) to bond with the bottom patch layer.
Blanchard teaches the patch comprises vent holes (Fig. 18, items 314a) for venting of gas and excess adhesive [0113], which leads to a smooth skin surface with optional assistance from a vacuum bag [0083] or caul sheet [0125]. Blanchard teaches the patch can comprise multiple plies [0114].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to substitute the patch and application process of Blanchard in place of the patch and application process taught by Stadtlander, in a sandwich structure repair taught by Stadtlander. This modification would provide a simplified means for repairing a cavity with a patch, allowing for venting gas and excess adhesive from the cavity through patch vent holes prior to cure to form a single cured mass, in place of the cavity filling / curing / grinding / patch application / 2nd curing process of Stadtlander; while still predictably resulting a smooth repair surface finish needed for an aircraft skin application.
Blanchard [0078] teaches the adhesive, similarly to Stadtlander, can comprise an epoxy or other suitable adhesive.
Stadtlander, in view of Blanchard, does not explicitly teach the epoxy adhesives of use as a ‘potting compound’.
However, the prior art of Grosskreuger provides evidence that epoxy adhesives used by Stadtlander and Blanchard are considered ‘potting compounds’ [Col. 7, lines 34-35].
2. The sandwich structure of claim 1, wherein: the patch comprises a relief hole extending through a thickness of the patch; and a portion of the cured potting compound is located within the relief hole.
With respect to claim 2, Blanchard teaches vent holes (Fig. 18, items 314a) are formed through the composite patch to relieve pressure by helping to squeeze out air (Fig. 18, items 1800) trapped within the layered of adhesive below the patch [0083], and also allow the escape of excess adhesive (Fig. 18, items 1804) from beneath the patch [0113].
3. The sandwich structure of claim 1, wherein the core comprises a honeycomb structure adjacent to the cavity, wherein: the honeycomb structure provides the first sheet and the second sheet a design bending strength; the cured potting compound in the cavity provides a repair bending strength; and the repair bending strength is equal to or greater than the design bending strength.
With respect to claim 3, Stadtlander teaches the cured potting compound in the patched cavity provides an improved strength to the sandwich structure [0015], so the bending strength of the repaired structure should prima facie obviously be greater than the bending strength of the original structure.
Stadtlander teaches a hollow aluminum core (Fig. 6, items 36; [0021]), filled with a low-density filler such as a foam adhesive, extends from the first layer to the second layer of the sandwich structure and surrounds the cured potting compound.
Stadtlander is silent on the structural design of the aluminum core, and does not explicitly teach a honeycomb structure.
However, Grosskrueger teaches the core can comprise an aluminum composite honeycomb core (Fig. 4, item 37) adjacent to the cavity, and between the first sheet and the second sheet [Col. 6, lines 37-40].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to substitute the aluminum composite honeycomb core, taught by Grosskrueger, to replace the aluminum core with unknown structural design, in the sandwich structure taught by Stadtlander; this modification would predictably result in a known structural design of an aluminum composite honeycomb core in the sandwich structure of Stadtlander, in view of Blanchard and Grosskrueger.
Is this modified sandwich structure of Stadtlander, in view of Grosskrueger, the core is a honeycomb structure that surrounds the cured potting compound.
As the aluminum core structure of Stadtlander may be a honeycomb structure matching Grosskrueger, the bending strength improvement would prima facie obviously still apply to the modified sandwich structure of Stadtlander, in view of Blanchard and Grosskrueger.
4. The sandwich structure of claim 1, wherein the sandwich structure further comprises a bushing, and wherein: the core is a honeycomb structure that surrounds the cured potting compound; and the cured potting compound surrounds the bushing.
With respect to claim 4, as set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches the cured potting compound in the patched cavity surrounded by the original core structure of Stadtlander, which is a hollow aluminum core (Fig. 6, items 36; [0021]), filled with a low-density filler such as a foam adhesive.
Stadtlander is silent on the structural design of the aluminum core, and does not explicitly teach a honeycomb structure.
However, Grosskrueger teaches the core can comprise an aluminum composite honeycomb core (Fig. 4, item 37) adjacent to the cavity, and between the first sheet and the second sheet [Col. 6, lines 37-40]. Grosskrueger also teaches a threaded insert, or bushing (Fig. 4, item 40), can be placed within the upper cavity, and surrounded by the potting compound [Col. 6, line 66 – Col. 7, line 33]. Grosskrueger teaches that the potting compound cures the bushing in place [Col. 7, lines 34-62].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to substitute the aluminum composite honeycomb core and comprising a threaded bushing, taught by Grosskrueger, in place the aluminum core with unknown structural design, in the sandwich structure taught by Stadtlander; this modification would predictably result in a known structural design of an aluminum composite honeycomb core in the sandwich structure of Stadtlander, in view of Blanchard and Grosskrueger, with a bushing available to engage with a fastener through the patch, if desired.
5. The sandwich structure of claim 1, wherein: the sandwich structure is an aircraft comprising an external wetted surface; and the outer surface of the first sheet and the patch of the structural reinforcement define the external wetted surface of the aircraft.
With respect to claim 5, Blanchard teaches the repair patch is applicable for the curved skin panel of an aircraft [0067].
6. The sandwich structure of claim 1, wherein the core is made of a foam material, and the cured potting compound extends through a partial thickness of the core.
With respect to claim 6, Stadtlander teaches the core can be made of a foam material (Fig. 5, items 36 or 38; [0021]). Stadtlander teaches the cured potting compound extends through a partial thickness of the core, as “a thin layer of aluminum core 136 remains below slot (repair cavity) 128b” (Fig. 11, item 128b; [0043]).
7. The sandwich structure of claim 1, wherein: the first sheet further comprises: an inner surface opposite the outer surface; and a peripheral edge through a thickness of the first sheet that extends between the outer surface and the inner surface of the first sheet; the second sheet further comprises an inner surface; the patch comprises a first surface opposite a second surface; and the cured potting compound is bonded to a portion of the inner surface of the first sheet, to the peripheral edge of the first sheet, to the inner surface of the second sheet, to an entirety of the first surface of the patch, and to a portion of the second surface of the patch.
With respect to claim 7, as set forth in the rejection of claim 1, the sandwich structure of Stadtlander, in view of Blanchard and Grosskrueger, teaches the first sheet further comprises: an inner surface opposite the outer surface; and a peripheral edge through a thickness of the first sheet that extends between the outer surface and the inner surface of the first sheet; the second sheet further comprises an inner surface; the patch comprises a first surface opposite a second surface; and the cured potting compound is bonded to a portion of the inner surface of the first sheet, to the peripheral edge of the first sheet, and to an entirety of the first surface of the patch (See Fig. 6 of Stadtlander and Fig. 19 of Blanchard).
Stadtlander teaches an epoxy potting compound (Fig. 11, item 144) can contact the inner surface of the second sheet [0044].
Blanchard teaches the substituted patch in claim 1 comprises vent holes, allowing excess potting compound (Fig. 18, items 1804) to vent out to a portion of the second surface of the patch [0113, 0116].
8. The sandwich structure of claim 7, wherein the inner surface of the second sheet further comprises an adhesive directly interposed between the second sheet and the cured potting compound in the cavity.
With respect to claim 8, in an alternate embodiment (Figure 8), Stadtlander teaches the inner surface of the second sheet contacts the potting material (item 54) that wraps around the cavity from the first layer. The potting material (item 54) is interposed between the second sheet and the cured potting compound (see Fig. 11, item 144) in the cavity as set forth in the rejection of claim 7.
9. The sandwich structure of claim 1, wherein the patch is made of a fiber-reinforced polymer comprising fibers embedded in a matrix.
With respect to claim 9, Blanchard teaches the substituted patch may comprise multiple plies of pre-cured or uncured composite materials [0114].
Blanchard does not explicitly teach the composite to be a fiber-reinforced polymer comprising fibers embedded in a matrix.
However, it would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing that the composite patch in this application could be a fiber-reinforced polymer comprising fibers in a matrix, as ‘prepreg’ plies are commonly known in this field.
Stadtlander provides evidence of this by teaching “repair plies 50 and 52 may also be formed from pre-impregnated fiberglass. In an exemplary embodiment, plies 50 and 52 are impregnated with epoxy resin [0031]”.
14. The sandwich structure of claim 1, wherein: the patch has a length and a width defining an area of the patch; the patch has a patch curvature defined by at least one of a first radius along the length of the patch or a second radius along the width of the patch; and the patch curvature corresponds to a composite curvature of the first sheet.
With respect to claim 14, Blanchard teaches the patch is generally planar and circular [0113], and may conform to the contour or curvature of the skin panel [0110].
15. The sandwich structure of claim 14, wherein: the area of the patch is predetermined based on a size of the cavity formed in the first sheet and the core; and the first radius and the second radius are zero, such that the patch is planar.
With respect to claim 15, Blanchard teaches the patch is adapted to overlie the rework area [0009], with the rework area (Fig. 17, item 300) used as a template for the centering of the patch [0112]; wherein the patch can remain substantially planar [0110].
16. The sandwich structure of claim 1, wherein the cured potting compound extends only partially through the core.
With respect to claim 16, Stadtlander teaches embodiments where a portion of the core is left below the cavity and filled with an adhesive (Figs. 4 & 6, item 44) that is present beneath the potting compound (Figs. 4 & 6, item 46; [0027]), so the cured potting compound extends only partially through the core and does not contact the second sheet (Fig. 4, item 32).
17. The sandwich structure of claim 1, wherein the cured potting compound extends entirely through the core, such that the cured potting compound extends from an inner surface of the first sheet to an inner surface of the second sheet.
With respect to claim 17, as set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches the potting compound and stiffener fills all spaces of the repaired cavity, which extends up to the first sheet (See Fig. 6 of Stadtlander and Fig. 19 of Blanchard).
Stadtlander also teaches an embodiment wherein an adhesive (Fig. 11, item 144) can contact the potting compound in the cavity down to the inner surface of the second sheet [0044].
Stadtlander is silent on any details for this adhesive 144, and does not explicitly teach a potting compound being used to bond to the inner surface of the second sheet.
However, it would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to substitute the potting compound (Fig. 11, items 146 & 147) of Stadtlander in place of the unknown adhesive 144 of Stadtlander, as the potting compound is taught to have desired bonding with like materials of the first sheet, core, and stiffener, and because Stadtlander has not narrowed the adhesive types allowed for any performance reasons. This substitution modification would lead to potting compound being present throughout the core from the first layer to the second layer.
18. The sandwich structure of claim 1, wherein: the first sheet comprises an injection site extending through a thickness of the first sheet; a portion of the cured potting compound is located within the injection site; and the patch entirely covers the injection site in the first sheet.
With respect to claim 18, Stadtlander teaches the first sheet (Fig. 3, item 30) comprises an injection site (Fig. 3, item 28b - void) extending through a thickness of the first sheet [0020]; and as set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches a portion of the cured potting compound is located within the injection site; and the patch entirely covers the injection site in the first sheet.
19. The sandwich structure of claim 1, wherein: the sandwich structure is an aircraft comprising an internal non-wetted surface; and the outer surface of the first sheet and the patch of the structural reinforcement define the internal non-wetted surface of the aircraft.
With respect to claim 19, Stadtlander teaches the sandwich structure can be part of an acoustic liner of an aircraft engine [Claim 9] comprising an internal non-wetted engine liner surface (Fig. 2, item 10b).
As set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches the outer surface of the first sheet and the patch of the structural reinforcement defines the applicable non-wetted surface of the aircraft.
Claims 10-13 are rejected under 35 U.S.C. 103 as being unpatentable over Stadtlander (US20080263844A1, of record) in view of Blanchard (US20100276065A1, of record) and Grosskrueger (US6656299B1, of record), as set forth above in the rejection of claim 1, and further in view of Armstrong (WO2017081456A1, of record).
10. The sandwich structure of claim 1, wherein the patch comprises: a first ply having fibers embedded in a matrix to provide a strength to the first ply, the first ply defining a surface of the patch that is bonded to the cured potting compound; and a second ply having fibers embedded in a matrix to provide a strength to the second ply, wherein the first ply is oriented relative to the second ply to provide a predetermined reinforcement strength to the path.
With respect to claim 10, as set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches a repair patch may comprise multiple plies covering a repair cavity filled with potting compound in a sandwich structure.
Blanchard teaches the substituted patch may comprise multiple plies of pre-cured or uncured composite materials [0114].
Blanchard does not explicitly teach the composite to be a fiber-reinforced polymer comprising fibers embedded in a matrix.
However, it would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing that the composite patch in this application could be a fiber-reinforced polymer comprising fibers in a matrix, as ‘prepreg’ plies are commonly known in this field.
Stadtlander provides evidence of this by teaching “repair plies 50 and 52 may also be formed from pre-impregnated fiberglass. In an exemplary embodiment, plies 50 and 52 are impregnated with epoxy resin [0031]”.
Stadtlander, in view of Blanchard and Grosskrueger, are silent on orienting the first ply relative to the second ply to provide a predetermined reinforcement strength to the patch.
However, in a similar field of art, the prior art of Armstrong teaches a patch over a repaired cavity comprising a plurality of upper plies (Fig. 3, items 22B) comprising unidirectional fibrous material [0010] that extend over the outer surface of the sandwich structure beyond the cavity. Armstrong teaches the stacking sequence of the patch 20 may comprise a repeating pattern of ply orientations (e.g., I, II, III, IV and V) and ply types for upper plies 22B [0064]. This stacking orientation of plies can provide desired properties such as in-plane stiffness, bending stiffness and strength [0005, 0044].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to use the known technique of orienting unidirectional fiber prepreg layers, taught by Armstrong, to improve the first and second prepreg layers of the patch taught by Stadtlander, in view of Blanchard and Grosskrueger, in the same way; this modification for orienting the unidirectional fibers of the patch plies could provide improved control of the desired properties such as in-plane stiffness, bending stiffness and strength of the repair patch.
11. The sandwich structure of claim 10, wherein: the fibers of the first ply are oriented in a first direction; the fibers of the second ply are oriented in a second direction; and the first direction is angled relative to the second direction.
With respect to claim 11, Armstrong teaches the fibers of the first ply are oriented in a first direction; the fibers of the second ply are oriented in a second direction; and the first direction is angled relative to the second direction, for example – a relative 90° difference between unidirectional fiber directions of the patch plies [0064] to improve control of the desired properties such as in-plane stiffness, bending stiffness and strength of the repair patch [0005, 0044].
12. The sandwich structure of claim 1, wherein: the first sheet is made of a first material; the ply of the patch is made of a second material; and the first material has the same coefficient of thermal expansion as the second material.
With respect to claim 12, as set forth in the rejection of claim 1, Stadtlander, in view of Blanchard and Grosskrueger, teaches a repair patch can comprise multiple plies covering a repair cavity filled with potting compound in a sandwich structure.
Blanchard teaches the substituted patch may comprise multiple plies of pre-cured or uncured composite materials [0114].
Blanchard does not explicitly teach the composite to be a fiber-reinforced polymer comprising fibers embedded in a matrix.
However, it would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing that the composite patch in this application could be a fiber-reinforced polymer comprising fibers in a matrix, as ‘prepreg’ plies are commonly known in this field.
Stadtlander provides evidence of this by teaching “repair plies 50 and 52 may also be formed from pre-impregnated fiberglass. In an exemplary embodiment, plies 50 and 52 are impregnated with epoxy resin [0031]”.
However, in a similar field of art, the prior art of Armstrong teaches a patch over a repaired cavity comprising a plurality of upper plies (Fig. 3, items 22B) which can comprise unidirectional fibrous material [0010] that extends over the outer surface of the sandwich structure beyond the cavity. Armstrong teaches the fibers can be pre-impregnated in a polymer matrix, and can use commercial prepregs, such as epoxy repair plies [0056]; and the stacking orientation of plies can provide desired properties such as in-plane stiffness, bending stiffness and strength [0005, 0044].
Armstrong teaches the composite materials may, for example, include fiber reinforcement materials such as carbon, aramid and/or glass fibers embedded into a thermosetting or thermoplastic matrix material [0044].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to use the known technique of orienting unidirectional fiber prepreg layers of selected materials, taught by Armstrong, to improve the first and second prepreg layers of the patch taught by Stadtlander, in view of Blanchard and Grosskrueger, in the same way; this modification for orienting the unidirectional fibers of the patch plies could provide improved control of the desired properties such as in-plane stiffness, bending stiffness and strength of the repair patch.
If select materials for the patch layers from the list provided by Armstrong were used having the same unidirectional fiber type, but using different matrix material types with matching coefficients of thermal expansion, this selection of patch layer material types could prima facie obviously teach the instant claim 12 elements of the first sheet is made of a first material; the ply of the patch is made of a second material; and the first material would have approximately the same coefficient of thermal expansion as the second material.
13. The sandwich structure of claim 12, wherein the first material is the same material as the second material.
With respect to claim 13, the two patch layers could be selected to have a matching fiber type, fiber structure, and resin type from the options taught by Armstrong, selected to provide desired properties such as in-plane stiffness, bending stiffness and strength [0044].
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Blanchard (US20100276065A1, of record), in view of Armstrong (WO2017081456A1, of record), as evidenced by Grosskrueger (US6656299B1, of record).
20. A structural reinforcement for reinforcing a sandwich structure, the structural reinforcement comprising: a cured potting compound; and a patch comprising: a first ply having fibers embedded in a matrix to provide a strength to the first ply, the first ply defining a surface of the patch that is bonded to the cured potting compound; and a second ply having fibers embedded in a matrix to provide a strength to the second ply, wherein the first ply is oriented relative to the second ply to provide a predetermined reinforcement strength to the patch; wherein the cured potting compound is configured to extend from a cavity of the sandwich structure onto an outer surface of the sandwich structure; the cured potting compound within the cavity is materially continuous with the cured potting compound extending onto the outer surface, such that the cured potting compound forms a single cured mass; and the cured potting compound forming the single cured mass is configured to adhere the patch to the outer surface of the sandwich structure.
With respect to claim 20, the prior art of Blanchard teaches a structural reinforcement for reinforcing a sandwich structure, an aircraft skin panel comprising a plurality of plies (Fig. 19, item 312b; [0110]).
Blanchard teaches an adhesive (Fig. 19, item 336; [0114]) to fill a repair cavity and bond a patch (Figs. 18 & 19, item 314; [0113]) onto a first sheet (surface) layer. Blanchard teaches the cavity repair for a top sheet and core layers of an airplane skin panel application (Fig. 19, item 312; [0110]).
Blanchard teaches the cavity repair comprises filling the cavity with an adhesive and applying the adhesive onto the first sheet layer (Fig. 19, item 328) to bond with the bottom patch layer.
Blanchard teaches the patch comprises vent holes (Fig. 18, items 314a) for venting of gas and excess adhesive [0113], which leads to a smooth skin surface with optional assistance from a vacuum bag [0083] or caul sheet [0125]. Blanchard teaches the patch is a composite and can comprise multiple plies [0114].
Blanchard is silent on the multiple-ply composite patch comprising oriented fibers.
However, in a similar field of art, the prior art of Armstrong teaches a patch over a repaired cavity comprising a plurality of upper plies (Fig. 3, items 22B) comprising unidirectional fibrous material [0010] that extend over the outer surface of the sandwich structure beyond the cavity. Armstrong teaches the stacking sequence of the patch 20 may comprise a repeating pattern of ply orientations (e.g., I, II, III, IV and V) and ply types for upper plies 22B [0064]. This stacking orientation of plies can provide desired properties such as in-plane stiffness, bending stiffness and strength [0005, 0044].
It would have been prima facie obvious to a person of ordinary skill in the art prior to the time of filing to use the known technique of orienting unidirectional fiber prepreg layers, taught by Armstrong, to improve the first and second prepreg layers of the patch taught by Blanchard in the same way; this modification for orienting the unidirectional fibers of the patch plies could provide improved control of the desired properties such as in-plane stiffness, bending stiffness and strength of the repair patch.
Blanchard teaches a continuous adhesive application (Fig. 19, item 336; [0114]) to fill a repair cavity and bond a patch (Figs. 18 & 19, item 314; [0113]) onto a first sheet (surface) layer, wherein the adhesive forms a single cured mass.
Blanchard teaches the patch comprises vent holes (Fig. 18, items 314a) for venting of gas and excess adhesive [0113], which leads to a smooth skin surface with optional assistance from a vacuum bag [0083] or caul sheet [0125].
Blanchard teaches the adhesive can comprise an epoxy or other suitable adhesive [0078].
Blanchard does not explicitly teach the epoxy adhesive of use as a ‘potting compound’.
However, the prior art of Grosskreuger provides evidence that the epoxy adhesive used by Blanchard can be considered a ‘potting compound’ [Col. 7, lines 34-35].
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to GREGORY C GROSSO whose telephone number is (571)270-1363. The examiner can normally be reached on M-F 8AM - 5PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Abbas Rashid can be reached on 571-270-7457. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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GREGORY C. GROSSO
Examiner
Art Unit 1748
/GREGORY C. GROSSO/Examiner, Art Unit 1748
/Abbas Rashid/Supervisory Patent Examiner, Art Unit 1748
Prosecution Insights