DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This is in response to Applicant’s arguments and amendments filed on 06/23/2026 amending Claims 1, 11, and 16. Claims 1 – 5, 9 – 16, and 18 – 24 are examined.
Claim Objections
Claim 1 is objected to because of the following informalities:
Claim 1, l. 8 “comprises a metallic liner structure” is believed to be in error for --comprises [[a]] the metallic liner structure-- because Claim 1, l. 7 previously recited “a metallic liner structure”.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
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 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 nonobviousness.
Claims 1 – 5, 9 – 16, 19, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Wilson et al. (6,235,359) in view of Beck et al. (10,527,003) in view of Fite, Jr. (3,056,171) in view of Kobbeman (2,957,309) in view of Hutter (3,483,703) in view of Martin (3,802,346).
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Regarding Claim 1, Wilson teaches, in Fig. 1 and Col. 5, l. 55 to Col. 6, l. 5, the invention as claimed, including rocket motor (Fig. 1) comprising: a nozzle (labeled in Fig. 1); a combustion chamber (space inside motor case) configured to carry a propellant grain (16); and a motor case (12) enclosing the combustion chamber (shown in Fig. 1), the motor case (12) having a longitudinal body (along the longitudinal axis) having a head end (labeled) and a nozzle end (labeled) towards the nozzle (labeled), the motor case (12) comprising an external wall (12, best seen in the enlarged portion of Fig. 1) and an internal wall (14) configured to be in contact with the propellant grain (16, shown in the enlarged portion of Fig. 1).
Wilson is silent on said external wall and said internal wall being an external metallic wall and an internal metallic wall formed as a monolithic piece, the internal metallic wall in a metallic liner structure, wherein the internal metallic sacrificial wall comprises a metallic liner structure positioned on an inner side of the motor case.
Beck teaches, in Figs. 1 – 7, Abstract, Col. 2, ll. 25 - 36, Col. 3, l. 60 to Col. 4, l. 5, Col. 9, ll. 1 – 40, and Col. 10, ll. 1 – 5, a similar rocket motor (100) having an external metallic wall (106) and an internal metallic wall (107) that were formed as a monolithic piece (single piece) motor case (102, 103) by additive manufacturing, in this case direct laser metal sintering (DLMS). Beck further teaches the internal metallic wall in a metallic liner structure (structure of the wall) positioned on an inner side of the motor case.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson to have the external wall and the internal wall be metallic walls formed as part of a monolithic piece using an additive manufacturing process, wherein the internal metallic sacrificial wall comprises a metallic liner structure positioned on an inner side of the motor case, taught by Beck, because Beck teaches, in the Abstract and Col. 9, ll. 1 – 40, that additive manufacturing greatly simplified the overall design and assembly of rocket motors since a rocket motor could be manufactured as a single monolithic piece having complex geometries that were difficult or impossible to achieve using traditional, subtractive machining techniques, e.g., milling, turning, drilling, grinding, etcetera.
Wilson, i.v., Beck, as discussed above, is silent on said internal metallic wall being an internal metallic sacrificial wall, i.e., configured to be sacrificial during combustion of the propellant.
Fite teaches, in Fig. 1, Col. 3, ll. 1 – 15, and Col. 4, ll. 45 – 50, a similar rocket motor having a combustion chamber (11) configured to carry propellant (12) for propelling the rocket; a motor case (10-15) enclosing the combustion chamber (11), the motor case comprising an external wall (10) and an internal wall (15) configured to be sacrificial during combustion of the propellant. Fite teaches, in Col. 4, ll. 45 – 50, that during combustion of the propellant the inner surface of the internal wall was consumed, i.e., sacrificed, but retained its form due to the short burning duration of the solid propellant. Fite teaches, in Col. 4, ll. 55 – 60, that combustion of solid propellant generated temperatures in excess of 4,900 °F. [Note: The following well-known in the art statement is taken to be admitted prior art because Applicant failed to traverse Examiner’s assertion of Official Notice in the Office Action mailed on 02/23/2026 in Applicant’s reply filed on 06/23/2026. MPEP 2144.03(C)] Examiner takes Official Notice that metals such as stainless steel and copper alloys, cited by Beck, had melting points that were significantly lower than the at least 4,900 °F combustion temperature of solid propellant. For example, stainless steel had a melting point of 2,500 °F to 2785 °F (1375 °C to 1530 °C) depending on the specific grade and copper alloys had a melting point of 1,650 °F to 1,900 °F (900 °C to 1,030 °C) which were significantly less than the at least 4,900 °F combustion temperature of solid propellant.
Thus, improving a particular device (rocket motor), based upon the teachings of such improvement in Fite, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the rocket motor of Wilson, i.v., Beck, and the results would have been predictable and readily recognized, that during combustion of solid propellant in the combustion chamber of the rocket motor of Wilson, i.v., Beck, a portion of the thinner internal metallic wall would have been consumed, i.e., sacrificed, due to the extremely high combustion temperatures while the thicker external metallic wall provided the mechanical strength necessary to contain the high temperature and high pressure combustion gases within the combustion chamber. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Wilson, i.v., Beck and Fite, as discussed above, is silent on said metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle.
Kobbeman teaches, in Figs. 1 - 3, Col. 4, ll. 1 – 5, and Col. 4, ll. 45 – 60, a similar rocket motor (11) having a motor case (12) comprising a metallic (Col. 4, ll. 1 – 5 “aluminum, or like resilient material”) liner structure (34, 45) configured to contact a propellant grain (31), the metallic liner structure (34, 45) having a radially weakening geometry (shown in Figs. 2 and 3, Col. 4, ll. 1 – 5 “Corrugated material 45”. Applicant’s Specification Para. [0064] disclosed “…a liner geometry that is best shown in FIG. 5C. The liner geometry may take the form of a corrugated geometry or any geometry that may weaken the liner structure 510.” Compare Applicant’s Fig. 5C to Kobbeman’s Figs. 2 and 3) that [Examiner notes that the phrase “reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain” is a statement of intended use and the structure of the device as taught by Kobbeman can perform the function because Kobbeman teaches a similar corrugated geometry as Applicant’s Fig. 5C and Applicant’s Specification Para. [0064] disclosed that the corrugated geometry weakens, i.e., reduces radial stiffness, the metallic liner structure.] reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall (interpreted as a similar radial thickness metallic wall without the claimed metallic liner structure) such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry (corrugated geometry) defines a space (plurality of bell-shaped open spaces defined between 31 and 45, best seen in Fig. 3) between the metallic liner structure and the propellant grain (31) that [Examiner notes that the phrase “permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle” is a statement of intended use and the structure of the device as taught by Kobbeman can perform the function because Kobbeman teaches a similar corrugated geometry as Applicant’s Fig. 5C and Applicant’s Specification Para. [0064]. Furthermore, uncontained fluids, like combustion gases, naturally flowed from a region of high pressure to a region of lower pressure. When combustion of the propellant grain starts, the pressure of the combustion gases would be highest at the nozzle inlet end, i.e., the nozzle end, so high pressure combustion gases at the nozzle end would have naturally flowed through the channels to the head end until the pressure in the two ends equalized.] permits combustion gas to pass around an outer diameter of the propellant grain (31) toward the head end of the combustion chamber and toward the nozzle (As shown in Fig. 6, the plurality of longitudinal channels traversed the head end to the nozzle end of the propellant grain (31).) Hutter teaches, in Figs. 1 – 3 and Col. 3, ll. 30 – 40, a similar rocket motor (20) having a motor case (1) comprising a plurality of spaces (6, best seen in Figs. 2 and 3) between a propellant grain (2) and a liner (5) to improve airflow of the combustion chamber (3). Hutter teaches, in Col. 3, ll. 30 – 40, utilizing the plurality of spaces (6) to equalize the internal pressure and external pressure around the propellant grain (2), i.e., the pressure in the plurality of spaces (6) would match the pressure in the combustion chamber (3).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson, i.v., Beck and Fite, with said metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle, taught by Kobbeman and Hutter, because all the claimed elements, i.e., the rocket motor comprising a motor case enclosing a combustion chamber configured to carry a propellant grain, the motor case comprising a metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the metallic liner structure being in a corrugated geometry that creates a plurality of spaces, i.e., longitudinal channels traversing the head end to the nozzle end, between the propellant grain and the metallic liner structure would have facilitated improved airflow of the combustion chamber (equalize the pressures around the propellant grain - Hutter - Col. 3, ll. 30 – 40) and would have facilitated cushioning the propellant grain when the rocket motor was subjected to shocks or vibrations resulting in less likelihood that the propellant grain would have cracked or broken up during storage, handling, or operation, Kobbeman - Col. 4, ll. 45 – 65. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Wilson, i.v., Beck, Fite, Kobbeman, and Hutter, is silent on the metallic liner structure has a mechanical strength within 50% to 400% of a mechanical strength of the propellant grain. Examiner notes that 50% to 400% of a mechanical strength of the propellant grain is a very broad range.
Kobbeman further teaches, in Col. 2, ll. 13 – 17 and Col. 4, ll. 45 – 65, that the resilient metallic liner structure effectively compensated for thermal expansion and thermal contraction of the propellant grain due to changes in temperature by concurrently contracting or expanding, respectively resulting in a lower likelihood that the propellant grain would have cracked or broken up during storage, handling, or operation. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the mechanical strength of the resilient metallic liner structure of Kobbeman was about equal to or less than (around 100% or less) the mechanical strength of the propellant grain since propellant grain thermal expansion was compensated for by said resilient metallic liner structure contracting and since propellant grain thermal contraction was compensated for by said resilient metallic liner structure expanding. Martin teaches, in Figs. 1 – 7, Col. 1, ll. 30 – 42, and Col. 2, ll. 5 - 20, a similar rocket motor (Fig. 6) having a rigid metal motor case (30) comprising a liner structure (10) that was configured to be in contact with the propellant grain (35) where the liner structure had a mechanical strength that was less than or around the mechanical strength of the propellant grain (35). Martin teaches, in Col. 1, ll. 30 – 42 and Col. 2, ll. 5 - 20, that the liner structure facilitated avoiding destruction of the rocket motor due to cracks in the propellant grain at the time of ignition by greatly reducing or eliminating the propellant grain’s internal stress when the propellant grain contracted, i.e., shrink, during chill down.
Therefore, the mechanical strength of the metallic liner structure relative to the mechanical strength of the propellant grain was recognized as a result-effective variable, i.e. a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that having the mechanical strength of the metallic liner structure be less than or around the mechanical strength of the propellant grain facilitated preventing crack formation by greatly reducing or eliminating the propellant grain’s internal stress when the propellant grain expanded or contracted due to changes in temperature. Therefore, since the general conditions of the claim, i.e. that the liner structure had a mechanical strength that was less than or around the mechanical strength of the propellant grain, were disclosed in the prior art by Kobbeman and Martin, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the metallic liner structure taught by Wilson, i.v., Beck, Fite, Kobbeman, and Hutter, to have a mechanical strength within 50% to 400% of a mechanical strength of the propellant grain. Furthermore, the range of 50% to 400% of a mechanical strength of the propellant grain is recognized by the Examiner to be a very broad range, and a range that an ordinarily skilled artisan would have found obvious at the time of the invention.
Note 1: It has been held that “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A). It has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980); MPEP 2144.05(II)(B). In Smith v. Nichols, 88 U.S. 112, 118-19 (1874) the Supreme Court held that “a change in form, proportions, or degree "will not sustain a patent". It was held that "It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.", In re Williams, 36 F.2d 436, 438 (CCPA 1929); MPEP 2144.05(II)(A). Claiming that the metallic liner structure has a mechanical strength within 50% to 400% of a mechanical strength of the propellant grain involved only a change of degree and is therefore not such an invention as will sustain a patent.
Regarding Claim 11, Wilson teaches, in Fig. 1 and Col. 5, l. 55 to Col. 6, l. 5, the invention as claimed, including a method for making a rocket motor (Fig. 1) comprising a nozzle (labeled), the method comprising: forming a combustion chamber (space inside motor case) configured to carry a propellant grain (16); and forming a motor case (12) enclosing the combustion chamber (shown in Fig. 1), the motor case (12) having a longitudinal body (along the longitudinal axis) having a head end (labeled) and a nozzle end (labeled) towards the nozzle (labeled), the motor case (12) comprising an external wall (12, best seen in the enlarged portion of Fig. 1) and an internal wall (14) configured to contact the propellant grain (16, shown in the enlarged portion of Fig. 1).
Wilson is silent on said external wall and said internal wall being an external metallic wall and an internal metallic wall formed as a monolithic piece, wherein the internal metallic wall in a metallic liner structure, wherein the internal metallic wall comprises a metallic liner structure positioned on an inner side of the motor case.
Beck teaches, in Figs. 1 – 7, Abstract, Col. 2, ll. 25 - 36, Col. 3, l. 60 to Col. 4, l. 5, Col. 9, ll. 1 – 40, and Col. 10, ll. 1 – 5, a similar rocket motor (100) having an external metallic wall (106) and an internal metallic wall (107) that were formed as a monolithic piece (single piece) motor case (102, 103) by additive manufacturing, in this case direct laser metal sintering (DLMS). Beck further teaches the internal metallic wall in a metallic liner structure (structure of the wall) positioned on an inner side of the motor case.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson to have the external wall and the internal wall be metallic walls formed as part of a monolithic piece using an additive manufacturing process, wherein the internal metallic sacrificial wall comprises a metallic liner structure positioned on an inner side of the motor case, taught by Beck, because Beck teaches, in the Abstract and Col. 9, ll. 1 – 40, that additive manufacturing greatly simplified the overall design and assembly of rocket motors since a rocket motor could be manufactured as a single monolithic piece having complex geometries that were difficult or impossible to achieve using traditional, subtractive machining techniques, e.g., milling, turning, drilling, grinding, etcetera.
Wilson, i.v., Beck, as discussed above, is silent on said internal metallic wall being an internal metallic sacrificial wall, i.e., configured to be sacrificial during combustion of the propellant.
Fite teaches, in Fig. 1, Col. 3, ll. 1 – 15, and Col. 4, ll. 45 – 50, a similar rocket motor having a combustion chamber (11) configured to carry propellant (12) for propelling the rocket; a motor case (10-15) enclosing the combustion chamber (11), the motor case comprising an external wall (10) and an internal wall (15) configured to be sacrificial during combustion of the propellant. Fite teaches, in Col. 4, ll. 45 – 50, that during combustion of the propellant the inner surface of the internal wall was consumed, i.e., sacrificed, but retained its form due to the short burning duration of the solid propellant. Fite teaches, in Col. 4, ll. 55 – 60, that combustion of solid propellant generated temperatures in excess of 4,900 °F. [Note: The following well-known in the art statement is taken to be admitted prior art because Applicant failed to traverse Examiner’s assertion of Official Notice in the Office Action mailed on 02/23/2026 in Applicant’s reply filed on 06/23/2026. MPEP 2144.03(C)] Examiner takes Official Notice that metals such as stainless steel and copper alloys, cited by Beck, had melting points that were significantly lower than the at least 4,900 °F combustion temperature of solid propellant. For example, stainless steel had a melting point of 2,500 °F to 2785 °F (1375 °C to 1530 °C) depending on the specific grade and copper alloys had a melting point of 1,650 °F to 1,900 °F (900 °C to 1,030 °C) which were significantly less than the at least 4,900 °F combustion temperature of solid propellant.
Thus, improving a particular method (for making a rocket motor), based upon the teachings of such improvement in Fite, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the method for making a rocket motor of Wilson, i.v., Beck, and the results would have been predictable and readily recognized, that during combustion of solid propellant in the combustion chamber of the rocket motor of Wilson, i.v., Beck, a portion of the thinner internal metallic wall would have been consumed, i.e., sacrificed, due to the extremely high combustion temperatures while the thicker external metallic wall provided the mechanical strength necessary to contain the high temperature and high pressure combustion gases within the combustion chamber. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Wilson, i.v., Beck and Fite, as discussed above, is silent on said metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle.
Kobbeman teaches, in Figs. 1 - 3, Col. 4, ll. 1 – 5, and Col. 4, ll. 45 – 60, a similar rocket motor (11) having a motor case (12) comprising a metallic (Col. 4, ll. 1 – 5 “aluminum, or like resilient material”) liner structure (34, 45) configured to contact a propellant grain (31), the metallic liner structure (34, 45) having a radially weakening geometry (shown in Figs. 2 and 3, Col. 4, ll. 1 – 5 “Corrugated material 45”. Applicant’s Specification Para. [0064] disclosed “…a liner geometry that is best shown in FIG. 5C. The liner geometry may take the form of a corrugated geometry or any geometry that may weaken the liner structure 510.” Compare Applicant’s Fig. 5C to Kobbeman’s Figs. 2 and 3) that [Examiner notes that the phrase “reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain” is a statement of intended use and the structure of the device as taught by Kobbeman can perform the function because Kobbeman teaches a similar corrugated geometry as Applicant’s Fig. 5C and Applicant’s Specification Para. [0064] disclosed that the corrugated geometry weakens, i.e., reduces radial stiffness, the metallic liner structure.] reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall (interpreted as a similar radial thickness metallic wall without the claimed metallic liner structure) such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry (corrugated geometry) defines a space (plurality of bell-shaped open spaces defined between 31 and 45, best seen in Fig. 3) between the metallic liner structure and the propellant grain (31) that [Examiner notes that the phrase “permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle” is a statement of intended use and the structure of the device as taught by Kobbeman can perform the function because Kobbeman teaches a similar corrugated geometry as Applicant’s Fig. 5C and Applicant’s Specification Para. [0064]. Furthermore, uncontained fluids, like combustion gases, naturally flowed from a region of high pressure to a region of lower pressure. When combustion of the propellant grain starts, the pressure of the combustion gases would be highest at the nozzle inlet end, i.e., the nozzle end, so high pressure combustion gases at the nozzle end would have naturally flowed through the channels to the head end until the pressure in the two ends equalized.] permits combustion gas to pass around an outer diameter of the propellant grain (31) toward the head end of the combustion chamber and toward the nozzle (As shown in Fig. 6, the plurality of longitudinal channels traversed the head end to the nozzle end of the propellant grain (31).) Hutter teaches, in Figs. 1 – 3 and Col. 3, ll. 30 – 40, a similar rocket motor (20) having a motor case (1) comprising a plurality of spaces (6, best seen in Figs. 2 and 3) between a propellant grain (2) and a liner (5) to improve airflow of the combustion chamber (3). Hutter teaches, in Col. 3, ll. 30 – 40, utilizing the plurality of spaces (6) to equalize the internal pressure and external pressure around the propellant grain (2), i.e., the pressure in the plurality of spaces (6) would match the pressure in the combustion chamber (3).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson, i.v., Beck and Fite, with said metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle, taught by Kobbeman and Hutter, because all the claimed elements, i.e., the rocket motor comprising a motor case enclosing a combustion chamber configured to carry a propellant grain, the motor case comprising a metallic liner structure configured to contact the propellant grain, the metallic liner structure having a radially weakening geometry that reduces radial stiffness of the metallic liner structure relative to an unstructured metallic wall such that the metallic liner structure has mechanical properties comparable to the propellant grain and wherein the radially weakening geometry defines a space between the metallic liner structure and the propellant grain that permits combustion gas to pass around an outer diameter of the propellant grain toward the head end of the combustion chamber and toward the nozzle, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the metallic liner structure being in a corrugated geometry that creates a plurality of spaces, i.e., longitudinal channels traversing the head end to the nozzle end, between the propellant grain and the metallic liner structure would have facilitated improved airflow of the combustion chamber (equalize the pressures around the propellant grain - Hutter - Col. 3, ll. 30 – 40) and would have facilitated cushioning the propellant grain when the rocket motor was subjected to shocks or vibrations resulting in less likelihood that the propellant grain would have cracked or broken up during storage, handling, or operation, Kobbeman - Col. 4, ll. 45 – 65. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Wilson, i.v., Beck, Fite, Kobbeman, and Hutter, is silent on the metallic liner structure has a mechanical strength within 50% to 400% of a mechanical strength of the propellant grain. Examiner notes that 50% to 400% of a mechanical strength of the propellant grain is a very broad range.
Kobbeman further teaches, in Col. 2, ll. 13 – 17 and Col. 4, ll. 45 – 65, that the resilient metallic liner structure effectively compensated for thermal expansion and thermal contraction of the propellant grain due to changes in temperature by concurrently contracting or expanding, respectively resulting in a lower likelihood that the propellant grain would have cracked or broken up during storage, handling, or operation. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the mechanical strength of the resilient metallic liner structure of Kobbeman was about equal to or less than (around 100% or less) the mechanical strength of the propellant grain since propellant grain thermal expansion was compensated for by said resilient metallic liner structure contracting and since propellant grain thermal contraction was compensated for by said resilient metallic liner structure expanding. Martin teaches, in Figs. 1 – 7, Col. 1, ll. 30 – 42, and Col. 2, ll. 5 - 20, a similar rocket motor (Fig. 6) having a rigid metal motor case (30) comprising a liner structure (10) that was configured to be in contact with the propellant grain (35) where the liner structure had a mechanical strength that was less than or around the mechanical strength of the propellant grain (35). Martin teaches, in Col. 1, ll. 30 – 42 and Col. 2, ll. 5 - 20, that the liner structure facilitated avoiding destruction of the rocket motor due to cracks in the propellant grain at the time of ignition by greatly reducing or eliminating the propellant grain’s internal stress when the propellant grain contracted, i.e., shrink, during chill down.
Therefore, the mechanical strength of the metallic liner structure relative to the mechanical strength of the propellant grain was recognized as a result-effective variable, i.e. a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that having the mechanical strength of the metallic liner structure be less than or around the mechanical strength of the propellant grain facilitated preventing crack formation by greatly reducing or eliminating the propellant grain’s internal stress when the propellant grain expanded or contracted due to changes in temperature. Therefore, since the general conditions of the claim, i.e. that the liner structure had a mechanical strength that was less than or around the mechanical strength of the propellant grain, were disclosed in the prior art by Kobbeman and Martin, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the metallic liner structure taught by Wilson, i.v., Beck, Fite, Kobbeman, and Hutter, to have a mechanical strength within 50% to 400% of a mechanical strength of the propellant grain. Furthermore, the range of 50% to 400% of a mechanical strength of the propellant grain is recognized by the Examiner to be a very broad range, and a range that an ordinarily skilled artisan would have found obvious at the time of the invention. See Note 1 above.
Re Claims 2 and 12, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above, including wherein the metallic liner structure is part of a monolithic piece of the motor case that is formed by additive manufacturing, see the rejections of independent Claims 1 and 11 above.
Re Claims 3 and 13, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above; except, wherein the metallic liner structure has a reduced mechanical strength compared to a metallic wall without a metallic liner structure.
Martin further teaches, in Col. 1, ll. 15 – 20 and Col. 4, ll. 8 – 12, that the rocket motor had a rigid metal case (30) which was ordinarily made out of steel. As discussed in the rejections of independent Claims 1 and 11 above, Kobbeman taught, in Col. 4, ll. 1 – 5, that the metallic liner structure (45) was made out of aluminum, or like resilient material.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, with the metallic wall without a liner structure being made out of a rigid metal like steel, further taught by Martin, because all the claimed elements, i.e., the rocket motor comprising a motor case enclosing a combustion chamber configured to carry a propellant grain and the motor case being a metallic wall made out of a rigid metal like steel, were known in the art, and one skilled in the art could have substituted the rigid metal case wall, further taught by Martin, for the unknown case material of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, with no change in their respective functions, to yield predictable results, i.e., the rigid metal case wall without a metallic liner structure would have facilitated providing structural strength to the rocket motor during operation to contain the high pressure and high temperature combustion gases generated by combustion of the propellant grain inside the motor case so that propulsive thrust would be generated by only expelling said high pressure and high temperature combustion gases through a nozzle end of the rocket motor. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B). It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, the metallic liner structure (corrugated aluminum or like resilient material) would have had a reduced mechanical strength (flexible/resilient versus rigid) compared to a metallic wall without a liner structure (rigid metal motor case) because the metallic liner structure had to be flexible to allow the propellant grain to thermally expand and contract without inducing severe internal stresses that would have caused cracks to form in the propellant grain.
Re Claims 4 and 14, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above, including wherein the internal metallic sacrificial wall is spaced apart (shown in the enlarged portion of Wilson Fig. 1) from said external metallic wall (12) to form a passage space (space for the ablative layer), and an ablative layer (10 – Col. 5, ll. 55 – 60 “the ablative and insulation materials can be used as a chamber internal insulation liner, as shown in FIG. 1.”) is located in the passage space. As discussed in the Claim 1 and Claim 11 rejections above, Beck taught, in Figs. 4, 6, and 7, and Col. 10, ll. 30 – 45, a similar rocket motor (100) having a motor case (102, 103) having an external wall (106) and an internal wall (107) that is spaced apart from the external wall (106) to form a passage space (108 - gap shown in Figs. 4, 6, and 7) between the internal wall (107) and the external wall (106) formed as a monolithic piece by additive manufacturing.
Thus, improving a particular device/method (rocket motor/method of making a rocket motor), based upon the teachings of such improvement in Beck, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the rocket motor/method of making a rocket motor of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, and the results would have been predictable and readily recognized, that utilizing additive manufacturing to form a monolithic motor case comprising an external metallic wall and an internal metallic sacrificial wall that is spaced apart from said external metallic wall to form a passage space, said ablative layer is located in the passage space would have facilitated strengthening the motor casing, i.e., double walled, while still protecting the external wall from the high temperatures of the combusting propellant grain by locating the insulating ablative layer in the passage space between the internal metallic sacrificial wall and said external metallic wall, Kobbeman – Col. 4, ll. 55 - 65. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Re Claims 5 and 15, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above; except, wherein the metallic liner structure has a Young’s modulus between 100 PSI and 1000 PSI.
[Note: The following well-known in the art statement is taken to be admitted prior art because Applicant failed to traverse Examiner’s assertion of Official Notice in the Office Action mailed on 09/11/2025 in Applicant’s reply filed on 01/23/2026. MPEP 2144.03(C)] Examiner takes Official Notice that it was a scientific fact that the Young’s modulus was defined as the ratio of stress (σ) to strain (ε), in the linear elastic region of a material, where stress was the amount of force applied per unit area (σ = F/A) and strain was the displacement or deformation per unit length (ε = dl/l).
Therefore, the Young’s modulus of the metallic liner structure was recognized as a result-effective variable, i.e. a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that the Young’s modulus facilitated the calculation of the strain (displacement or deformation per unit length) when a known stress (force applied per unit area) was applied to the metallic liner structure. Therefore, since the general conditions of the claim, i.e. that the metallic liner structure had a Young’s modulus, was inherently disclosed in the prior art (every engineering material had a Young’s modulus), it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the metallic liner structure taught by Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, to have a Young’s modulus between 100 PSI and 1000 PSI so that the metallic liner structure would have deformed to match the deformation of the propellant grain. See Note 1 above.
Re Claim 16, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above, including wherein the motor case comprises the internal metallic sacrificial wall and the external metallic wall and the metallic liner structure is located on the internal metallic sacrificial wall, refer to the Claim 11 rejection above.
Re Claims 9 and 19, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above; except, wherein the external metallic wall and the internal metallic sacrificial wall are formed from an additive manufacturing process.
Beck further teaches, in Figs. 1 – 7, Abstract, Col. 3, l. 60 to Col. 4, l. 5, Col. 9, ll. 1 – 40, and Col. 10, ll. 1 – 5, a similar rocket motor (100) having a monolithic piece (single piece) of a motor case (102, 103) having an external metallic wall (106) and an internal metallic wall (107) that was formed by additive manufacturing, in this case direct laser metal sintering (DLMS).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, to have the external metallic wall and the internal wall are formed by additive manufacturing process, further taught by Beck, because Beck teaches, in the Abstract and Col. 9, ll. 1 – 40, that additive manufacturing greatly simplified the overall design and assembly of rocket motors since a rocket motor could be manufactured as a single monolithic piece having complex geometries that were difficult or impossible to achieve using traditional, subtractive machining techniques, e.g., milling, turning, drilling, grinding, etcetera.
Re Claims 10 and 20, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above; except, wherein the metallic liner structure has a Young’s modulus that is comparable to a Young’s modulus of the propellant grain.
[Note: The following well-known in the art statement is taken to be admitted prior art because Applicant failed to traverse Examiner’s assertion of Official Notice in the Office Action mailed on 09/11/2025 in Applicant’s reply filed on 01/23/2026. MPEP 2144.03(C)] Examiner takes Official Notice that it was a scientific fact that the Young’s modulus was defined as the ratio of stress (σ) to strain (ε), in the linear elastic region of a material, where stress was the amount of force applied per unit area (σ = F/A) and strain was the displacement or deformation per unit length (ε = dl/l).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, the metallic liner structure would have had a Young’s modulus that was comparable to a Young’s modulus of the propellant grain because the metallic liner structure facilitated avoiding destruction of the rocket motor due to cracks in the propellant grain at the time of ignition by greatly reducing or eliminating the propellant grain’s internal stress when the propellant grain contracted, i.e., shrink, during chill down. In other words, comparable Young’s moduli meant that the metallic liner structure and the propellant grain had similar ratios of stress to strain, so the metallic liner structure and the propellant grain would have similar deformations when they experienced the same stress. As discussed in the rejections of independent Claims 1 and 11 above, Kobbeman taught, in Col. 2, ll. 13 – 17 and Col. 4, ll. 45 – 65, that the resilient metallic liner structure effectively compensated for thermal expansion and thermal contraction of the propellant grain due to changes in temperature by concurrently contracting or expanding, respectively resulting in a lower likelihood that the propellant grain would have cracked or broken up during storage, handling, or operation. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that the resilient metallic liner structure would have had a Young’s modulus that was comparable to the Young’s modulus of the propellant grain since propellant grain thermal expansion was compensated for by said resilient metallic liner structure contracting and since propellant grain thermal contraction was compensated for by said resilient metallic liner structure expanding.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Wilson et al. (6,235,359) in view of Beck et al. (10,527,003) in view of Fite, Jr. (3,056,171) in view of Kobbeman (2,957,309) in view of Hutter (3,483,703) in view of Martin (3,802,346) as applied to Claim 14 above, and further in view of Liu (5,151,216).
Re Claim 18, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above; except, wherein the ablative layer is formed of an ablative material that is injection molded into the passage space.
Liu teaches, in Col. 3, ll. 20 – 25, Col. 14, l. 64 to Col. 15, l. 5, and Claim 18, an ablative material that was injection molded into a passage space (open space inside a closed mold) for use on the solid fuel rockets, i.e., rocket motors with solid propellent grains, of the space shuttle.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, with the ablative layer is formed of an ablative material that is injection molded into a passage space, taught by Liu, because all the claimed elements, i.e., the rocket motor comprising a motor case enclosing a combustion chamber configured to carry a propellant grain and an ablative layer formed from an ablative material that is injection molded into a passage space, were known in the art, and one skilled in the art could have substituted the injection moldable ablative material, taught by Liu, for the ablative material of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, with no change in their respective functions, to yield predictable results, i.e., the injection moldable ablative material would have been injected into the passage space defined between the external wall and the internal wall to form an ablative layer between the external wall and the internal wall. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Claims 21 - 24 are rejected under 35 U.S.C. 103 as being unpatentable over Wilson et al. (6,235,359) in view of Beck et al. (10,527,003) in view of Fite, Jr. (3,056,171) in view of Kobbeman (2,957,309) in view of Hutter (3,483,703) in view of Martin (3,802,346) and further in view of Lawrynowicz et al. (9,763,791).
Re Claims 21 and 23, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, teaches the invention as claimed and as discussed above, and Wilson further teaches an insulator-carrying surface (external metallic wall surface facing and in contact with the ablative and insulator material 10, Col. 5, l. 55 to Col. 6, l. 10) of the external metallic wall (12). Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, as discussed above, is silent on a set of surface structures on said insulator-carrying surface of the external metallic wall.
Lawrynowicz teaches, in Fig. 2, Col. 6, ll. 5 – 30, Col. 8, ll. 45 – 67, and Col. 9, ll. 1 – 20, a set of surface structures (T-shaped – 24, 32) on an insulator-carrying surface (interior side of 16 facing 18) of an external metallic wall (16, Col. 4, ll. 60 - 65), the set of surface structures (T-shaped – 24, 32) radially protruding from said insulator-carrying surface (interior side of 16 facing 18), wherein the set of surface structures (T-shaped – 24, 32) are shaped to provide mechanical retention of the insulator [18 - a polymer such as polyetherether ketone (PEEK) was an insulator]. Lawrynowicz teaches, in Col. 6, ll. 25 – 30, Col. 8, ll. 45 – 67, and Col. 9, ll. 1 – 10, that the T-shaped surface structures provided mechanical retention, i.e., mechanical interlocking, between the PEEK insulator (18) and the wall (16) with the insulator-carrying surface (interior side of 16 facing 18). Lawrynowicz further teaches, in Col. 8, ll. 50 – 55, that additive manufacturing processes can generate any three-dimensional (3D) interlocking structure, i.e., surface structures.
Thus, improving a particular device/method (rocket motor/method of making a rocket motor), based upon the teachings of such improvement in Lawrynowicz, would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, i.e., applying this known improvement technique in the same manner to the rocket motor/method of making a rocket motor of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin, and the results would have been predictable and readily recognized, that integrating a set of surface structures on the insulator-carrying surface of the external metallic wall and formed as part of the monolithic piece (i.e., single piece formed by an additive manufacturing process) would have resulted in the set of surface structures radially protruding from the insulator-carrying surface into the passage space, and the set of surface structures would have been shaped to facilitate providing mechanical retention of the ablative/insulator layer. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1396; MPEP 2143(C).
Re Claims 22 and 24, Wilson, i.v., Beck, Fite, Kobbeman, Hutter, Martin, and Lawrynowicz, teaches the invention as claimed and as discussed above, including wherein the set of surface structures is formed as part of an additive manufacturing process. As discussed above, Lawrynowicz taught, in Col. 8, ll. 50 – 55, that additive manufacturing processes can generate any three-dimensional (3D) interlocking structure, i.e., surface structures. As discussed above, Beck teaches, in the Abstract and Col. 9, ll. 1 – 40, that additive manufacturing greatly simplified the overall design and assembly of rocket motors since a rocket motor could be manufactured as a single monolithic piece having complex geometries that were difficult or impossible to achieve using traditional, subtractive machining techniques, e.g., milling, turning, drilling, grinding, etcetera.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, Martin, and Lawrynowicz, the set of surface structures would have been formed as part of an additive manufacturing process because Beck taught that additive manufacturing greatly simplified the overall design and assembly of rocket motors since a rocket motor could be manufactured as a single monolithic piece having complex geometries that were difficult or impossible to achieve using traditional, subtractive machining techniques, e.g., milling, turning, drilling, grinding, etcetera.
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.
Response to Arguments
Applicant's arguments filed 06/23/2026 have been fully considered but they are not persuasive.
In response to applicant's arguments on Pg. 8, first paragraph against references Beck and Fite individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). The independent claims were rejected based on the combination of Wilson, i.v., Beck, Fite, Kobbeman, Hutter, and Martin. Furthermore, the Supreme Court held in KSR that "A person of ordinary skill in the art is also a person of ordinary creativity, not an automaton.“ KSR, 550 U.S. at 421, 82 USPQ2d at 1397. "[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle.“ Id. at 420, 82 USPQ2d at 1397. Office personnel may also take into account "the inferences and creative steps that a person of ordinary skill in the art would employ.“ Id. at 418, 82 USPQ2d at 1396; MPEP 2141(II)(C) and MPEP 2141.03(I). The rejections are maintained.
In response to applicant's argument on Pg. 8, last paragraph that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). Applicant’s arguments failed to cite exactly what knowledge gleaned only from the applicant's disclosure. Furthermore, the Supreme Court held in KSR that "A person of ordinary skill in the art is also a person of ordinary creativity, not an automaton.“ KSR, 550 U.S. at 421, 82 USPQ2d at 1397. "[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle.“ Id. at 420, 82 USPQ2d at 1397. Office personnel may also take into account "the inferences and creative steps that a person of ordinary skill in the art would employ.“ Id. at 418, 82 USPQ2d at 1396; MPEP 2141(II)(C) and MPEP 2141.03(I). The rejections are maintained.
Correspondence
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/LORNE E MEADE/Primary Examiner, Art Unit 3741
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